Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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Membrane bioreactors for groundwater treatment
Hage, J.C. ; Tramper, J. ; Hartmans, S. - \ 2006
NPT Procestechnologie 13 (2006)1. - ISSN 1380-3638 - p. 9 - 11.
Membrane-aerated biofilm reactor for the removal of 1,2-dichloroethane by Pseudomonas sp strain DCA1
Hage, J.C. ; Houten, R.T. ; Tramper, J. ; Hartmans, S. - \ 2004
Applied Microbiology and Biotechnology 64 (2004)5. - ISSN 0175-7598 - p. 718 - 725.
biologische behandeling - membranen - ethyleendichloride - biofilms - biodegradatie - verwijdering - afvalwaterbehandeling - pseudomonas - insecticiden - beluchting - biological treatment - membranes - ethylene dichloride - biodegradation - removal - waste water treatment - insecticides - aeration - waste-gas treatment - aliphatic-compounds - aerobic biofilms - degradation - groundwater - bioreactor - kinetics - trichloroethylene - model - water
A membrane-aerated biofilm reactor (MBR) with a biofilm of Pseudomonas sp. strain DCA1 was studied for the removal of 1,2-dichloroethane (DCA) from water. A hydrophobic membrane was used to create a barrier between the liquid and the gas phase. Inoculation of the MBR with cells of strain DCA1 grown in a continuous culture resulted in the formation of a stable and active DCA-degrading biofilm on the membrane. The maximum removal rate of the MBR was reached at a DCA concentration of approximately 80 µM. Simulation of the DCA fluxes into the biofilm showed that the MBR performance at lower concentrations was limited by the DCA diffusion rate rather than by kinetic constraints of strain DCA1. Aerobic biodegradation of DCA present in anoxic water could be achieved by supplying oxygen solely from the gas phase to the biofilm grown on the liquid side of the membrane. As a result, direct aeration of the water, which leads to undesired coagulation of iron oxides, could be avoided
A membrane-aerated biofilm reactor (MBR) with a biofilm of Pseudomonas sp. strain DCA1 was studied for the removal of 1,2-dichloroethane (DCA) from water. A hydrophobic membrane was used to create a barrier between the liquid and the gas phase. Inoculation of the MBR with cells of strain DCA1 grown in a continuous culture resulted in the formation of a stable and active DCA-degrading biofilm on the membrane. The maximum removal rate of the MBR was reached at a DCA concentration of approximately 80 muM. Simulation of the DCA fluxes into the biofilm showed that the MBR performance at lower concentrations was limited by the DCA diffusion rate rather than by kinetic constraints of strain DCA1. Aerobic biodegradation of DCA present in anoxic water could be achieved by supplying oxygen solely from the gas phase to the biofilm grown on the liquid side of the membrane. As a result, direct aeration of the water, which leads to undesired coagulation of iron oxides, could be avoided.
Application of Pseudomonas sp. strain DCA1 for the removal of chlorinated hydrocarbons
Hage, J.C. - \ 2004
Wageningen University. Promotor(en): Hans Tramper, co-promotor(en): S. Hartmans. - [S.l.] : S.n. - ISBN 9085040795 - 126
oplosmiddelverwijdering - gechloreerde koolwaterstoffen - biofilms - bioreactoren - microbiële afbraak - pseudomonas - membranen - solvent removal - chlorinated hydrocarbons - bioreactors - microbial degradation - membranes
Enzymatic synthesis of thioglucosides using almond ß-glucosidase
Meulenbeld, G.H. ; Roode, B.M. de; Hartmans, S. - \ 2002
Biocatalysis and Biotransformation 20 (2002)4. - ISSN 1024-2422 - p. 251 - 256.
A selection of different glycosidases was screened for the glycosylation of 1-propanethiol. The g-glucosidases from almond, Aspergillus niger and Caldocellum saccharolyticum were capable of 1-propanethioglucoside (1-PTG) formation. The almond g-glucosidase showed the highest activity in this reversed hydrolysis type of reaction using glucose as glucosyl donor. Besides 1-propanethiol, also thioglucosides of 2-propanethiol and furfuryl mercaptan were formed by the almond g-glucosidase. The substrate specificity of the almond g-glucosidase with respect to thioglucosylation is restricted to primary and secondary aliphatic thiols. Once the thioglucosides are formed, they are not hydrolyzed at a significant rate by almond g-glucosidase. As a consequence the synthesis of 1-PTG could be observed at very low aglycone concentrations (0.5␟/v based on the reaction solution) and high yields (68␋ased on 1-PT and 41␋ased on glucose) were obtained. An excess of aglycone, otherwise frequently applied in reversed hydrolysis glycosylation, is therefore not necessary in the glucosylation of 1-PT.
Concominant extracellular accumulation of alpha-keto acids and higher alcohols by Zygosaccharomyces rouxii
Sluis, C. van der; Rahardjo, Y.S.P. ; Smit, B.A. ; Kroon, P.J. ; Hartmans, S. ; Schure, E.G. ter; Tramper, J. ; Wijffels, R.H. - \ 2002
Journal of Bioscience and Bioengineering 93 (2002). - ISSN 1389-1723 - p. 117 - 124.
Alpha-keto acids are key intermediates in the formation of higher alcohols, important flavor components in soy sauce, and produced by the salt-tolerant yeast Zygosaccharomyces rouxii. Unlike most of the higher alcohols, the alpha-keto acids are usually not extracellularly accumulated by Z. rouxii when it is cultivated with ammonium as the sole nitrogen source. To facilitate extracellular accumulation of the alpha-keto acids from aspartate-derived amino acid metabolism, the amino acids valine, leucine, threonine and methionine were exogenously supplied during batch and A-stat cultivations of (mutants of) Z. rouxii. It was shown that all alpha-keto acids from the aspartate-derived amino acid metabolism, except alpha-ketobutyrate, could be extracellularly accumulated. In addition, it appeared from the concomitant extracellular accumulation of alpha-keto acids and higher alcohols that in Z. rouxii, valine, leucine and methionine were converted via Ehrlich pathways similar to those in Saccharomyces cerevisiae. Unlike these amino acids, threonine was converted via both the Ehrlich and amino acid biosynthetic pathways in Z. rouxii.
Klaasje J. Hartmans : investeren in onderzoek naar plantaardige bestrijdingsmiddelen noodzakelijk
Delft, R. van - \ 2001
Aardappelwereld 55 (2001)4. - ISSN 0169-653X - p. 4 - 5.
aardappelen - investering - opslag - behoud - bestraling - pesticiden - gewasbescherming - wetgeving - agrarisch recht - nederland - europa - onderzoek - recht - potatoes - storage - preservation - irradiation - pesticides - plant protection - investment - legislation - agricultural law - research - netherlands - europe - law
Bij het zoeken naar een alternatief voor kiemremmingsmiddelen voor de aardappel ontdekte men de plantaardige stof carvon als goede vervanger. De regelgeving in Nederland en binnen Europa is dermate dichtgetimmerd, dat zelfs het onderzoek naar toepassing van dit middel, dat gewonnen kan worden uit Karwijzaad, geldverslindend wordt
Co-metabolic degradation of chlorinated hydrocarbons by Pseudomonas sp. strain DCA1
Hage, J.C. ; Kiestra, F.D.G. ; Hartmans, S. - \ 2001
Applied Microbiology and Biotechnology 57 (2001). - ISSN 0175-7598 - p. 548 - 554.
Thioglucosidase activity from Sphingobacterium sp. strain OTG1
Meulenbeld, G.H. ; Hartmans, S. - \ 2001
Applied Microbiology and Biotechnology 56 (2001). - ISSN 0175-7598 - p. 700 - 706.
Screening for novel thioglucoside hydrolase activity resulted in the isolation of Sphingobacterium sp. strain OTG1 from enrichment cultures containing octylthioglucoside (OTG). OTG was hydrolysed into octanethiol and glucose by cell free extracts. Besides thioglucoside hydrolysis, several other glucoside hydrolase activities were detected in the Sphingobacterium sp. strain OTG1 cell free extract. By adding β-glucosidase inhibitors it was possible to discriminate between these different activities. Ascorbic acid and D-gluconic acid lactone inhibited the hydrolysis of p-nitrophenyl β-glucoside, but did not affect octyl- and octylthioglucoside hydrolase activity. Besides OTG, various other thioglucosides were hydrolysed by the novel thioglucosidase, with almost the same activities regardless of the nature of the aglycone, including the myrosinase model substrate sinigrin (a glucosinolate). Sinigrin could also be used as a growth substrate by Sphingobacterium sp. strain OTG1, although at concentrations exceeding 0.15 mM degradation was not complete.
Enzymatic glucosylation: sucrose glucosyltransferases and glucosidases in O- and S-glucoside synthesis
Meulenbeld, G.H. - \ 2001
Wageningen University. Promotor(en): A.G.J. Voragen; S. Hartmans. - S.l. : S.n. - ISBN 9789058085269 - 112
sucrose - glucose - catechine - glycosyltransferasen - catechin - glycosyltransferases
<p>Glycosylation is considered as a useful method for improving chemical properties like solubility and volatility of compounds with interesting organoleptic or physiological properties. The aim of the research described in this thesis was to explore the enzymatic glycosylation of aglycones (nonsaccharide acceptor molecules). The initial focus is on the glucosylation of aromatic alcohols by non-Leloir glucosyltransferases like sucrose glucosyltransferases.<br/>Several streptococcal sucrose glucosyltransferases (glucansucrases) were screened for transglucosylation activity using the flavonoid catechin as model aglycone and sucrose as an economically feasible glucosyl donor substrate (Chapter 2). <em>Streptococcus</em><em>mutans</em> GS-5 glucosyltransferase-D (GTF-D) glucosylated catechin most efficiently (90% catechin yield). Three different catechin glucosides were isolated of which two catechin glucoside structures were spectroscopically elucidated; catechin-4'- <em>O</em> -α-D- and catechin-4',7- <em>O</em> -α-di-D-glucopyranoside. The structure of the third glucoside remained unsolved, although hydrolysis studies using <em>Aspergillus</em><em>niger</em> amyloglucosidase suggested that catechin-7- <em>O</em> -α-D-glucopyranoside was formed. The acceptor specificity of GTF-D towards aromatic aglycones is restricted to compounds containing two adjacent aromatic hydroxyl groups, e.g. (substituted) catechol(s) (Chapter 3). This suggests that one hydroxyl group is involved in the interaction with GTF-D, while the other is available for formation of the glucosidic linkage. Compounds containing one hydroxyl group like phenol, irreversibly inhibit GTF-D transglucosylation activity.<br/>To facilitate the transglucosylation of less water soluble aglycones, the addition of water miscible organic solvents (cosolvents) was studied (Chapter 3). Bis-2-methoxyethyl ether (MEE) was selected as the most appropriate cosolvent. MEE addition resulted in a 4-fold increase in catechin transglucosylation activity due to a 12-fold increase in catechin solubility. Addition of MEE (10-30% v/v) also enabled the glucosylation of catechol aglycones at otherwise inhibitory concentrations (200 mM). This was explained by assuming that the partitioning of the aglycone between solvent and enzyme was changed upon MEE addition.<br/>The addition of bis-2-methoxyethyl ether also affected the formation rate and absolute amounts of glucan formed (Chapter 4). An increase of 20% in reducing sugars was observed using 20% (v/v) MEE. Besides an increase in sucrose hydrolysis there was also an increase the formation of high molecular weight glucan chains (10 <sup>2</SUP>-10 <sup>3</SUP>kDa). Linkage analysis showed that also the type of glucosidic linkage was affected upon MEE addition. Glucan formed in the presence of MEE contained an increased amount ofα(1,3) linkages. It was hypothesised that MEE affected glucan formation through modifying the GTF-D glucan binding domain.<br/>The accumulation of fructose was shown to inhibit aglycon glucosylation and glucan formation. To overcome this inhibition, the fructose consuming yeasts <em>Pichia</em><em>pastoris</em> and the mutant <em>Saccharomyces</em><em>cerevisiae</em> T2-3D were added (Chapter 2). Both yeasts are incapable of utilising sucrose. Due to the consumption of fructose during transglucosylation, an increase in glucoside yield and the maximum duration of catechin glucosylation was observed. Consequently, the consumption of sucrose by GTF-D increased. Eventually glucosylation yields by GTF-D could be engineered either by adding MEE or by fructose consuming yeasts (Chapter 2 and 3). Using MEE, the glucoside yield based on catechin decreased and the sucrose based yield increase. The addition of the yeasts resulted in an increased catechin based glucoside yield and a decreased sucrose based glucoside yield.<br/>In the second part of this thesis the attention is focussed on glycosidases and the hydrolysis and formation of thioglucosides. The observed stability of thioglucosides towards enzymatic hydrolysis was used to screen for new thioglucoside active enzymes (Chapter 5). Using octylthioglucoside (OTG) as a carbon source for microbial growth, <em>Sphingobacterium</em> sp. strain OTG1 was isolated. In the cell free extract a novel thioglucoside hydrolase activity was observed, showing distinct characteristics compared to typicalβ- or thioglucosidases. Various thioglucosides were hydrolysed by the <em>Sphingobacterium</em> cell free extract, with almost the same activities.<br/>In view of the aim of this thesis, the synthesis of glycosides, various glycosidases were screened for the glycosylation of 1-propanethiol (Chapter 6). Theβ-glucosidase from almond, <em>Aspergillus</em><em>niger</em> and <em>Caldocellum</em><em>saccharolyticum</em> showed thioglucosylation activity using glucose and 1-propanetiol. The almond enzyme showed the highest activity (3μmol.min <sup>-1</SUP>.mg <sup>-1</SUP>). Only primary and secondary (10-fold slower reaction rate) aliphatic thiols were glucosylated. Of the different thiols examined, the glucosylation of furfuryl mercaptan is the most interesting because of the potential of the glucoside as a flavour precursor.<br/>Because of the stability of thioglucosides towards most enzymatic hydrolases (glycosidases), an excess of aglycone otherwise frequently applied in reversed hydrolysis glycosylation is not necessary for thioglucosylation. Consequently, high yields up to 60% based on 1-propanethiol and 40% based on glucose were obtained for the synthesis of 1-propanethioglucoside.</p>
Enzymatic modification of bacterial exopolysaccharides : xanthan lyase as a tool for structural and functional modification of xanthan
Ruijssenaars, H.J. - \ 2001
Wageningen University. Promotor(en): J.A.M. de Bont; S. Hartmans. - S.l. : S.n. - ISBN 9789058083739 - 95
polysacchariden - xanthan - lyasen - biodegradatie - polysaccharides - lyases - biodegradation
<p>Bacterial extracellular polysaccharides (EPSs) can be applied, e.g., in foods, as a thickener or stabilizer. The functional properties that make a polysaccharide suitable for such applications are largely determined by the primary structure, i.e., the sugar composition, the linkage types between the sugar units, and the presence of side chains and non-sugar substituents. The aim of this research was to obtain EPS-modifying enzymes that could be used as tools both for studying structure-function relationships of (food-grade) EPSs and for the production of tailor-made EPSs with a specific, desired functionality. EPS-degrading microorganisms could serve as a source of such enzymes.</p><p>To get an idea of the probability of finding EPS-degrading microorganisms, a comparative biodegradability study was carried out on eight EPSs, six of which were produced by lactic acid bacteria (Chapter 2). Human faeces or soil were used as inocula. Xanthan, clavan, and the EPSs of <em>Streptococcus thermophilus</em> strains SFi39 and SFi12 were readily degraded. The four other EPSs, produced by <em>Lactococcus lactis</em> ssp. <em>cremoris</em> B40, <em>Lactobacillus sakei</em> 0-1, <em>S. thermophilus</em> SFi20, and <em>Lactobacillus helveticus</em> Lh59, were not. Xanthan, the most relevant food-grade EPS, was chosen as the target for further studies.</p><p>For efficient screening of polysaccharide-degrading microorganisms, plate methods are required that discriminate between intact and degraded polysaccharide. Such methods can make use of specific physicochemical properties of the polysaccharide, such as complex formation with dyes and gelling capacity. Alternatively, dye-labelled polysaccharides can be applied. Chapter 3 presents a survey of plate methods based on the above principles.</p><p>A mixed xanthan-degrading culture was obtained from soil by enrichment on xanthan. From this culture, <em>Paenibacillus alginolyticus</em> XL-1 was isolated. This strain degraded 28% of the xanthan molecule and appeared to leave the backbone intact. Several xanthan-degrading enzymes were excreted during growth on xanthan, including a xanthan lyase. Xanthan lyase removes the terminal mannosyl residue of the trisaccharide xanthan side chain by aβ-eliminative mechanism, resulting in a double bond in the side chain glucuronyl residue. Xanthan lyase is the only polysaccharide lyase that is exo-acting, releasing residues from the outside of a polysaccharide molecule. All other polysaccharide lyases described to date are endo-acting, attacking the polysaccharide backbone. In <em>P. alginolyticus</em> XL-1, xanthan lyase production is induced by xanthan and inhibited by glucose and low-molecular-weight enzymatic degradation products from xanthan. A 97-kDa xanthan lyase was purified and characterized. The enzyme is specific for pyruvated mannosyl side chain residues and optimally active at pH 6.0 and 55°C (Chapter 4).</p><p>The gene encoding the pyruvated mannose-specific xanthan lyase of <em>P</em> . <em>alginolyticus</em> XL-1, designated <em>xalA</em> , was isolated. The <em>xalA</em> gene encodes a 936-amino acid protein, including a 36-amino acid signal sequence. The XalA protein belongs to polysaccharide lyase family 8, which until now only contained chondroitinases and hyaluronate lyases. The part of the <em>xalA</em> gene encoding the 900-amino acid, 96,887-Da mature enzyme was expressed functionally in <em>Escherichia coli</em> . Like the native enzyme, the recombinant enzyme is specific for pyruvated xanthan. Heterologous production of XalA in <em>E. coli</em> increased the volumetric productivity by a factor 30, compared to production by <em>P. alginolyticus</em> . The recombinant xanthan lyase was used as a tool to modify xanthan, which resulted in a dramatic loss of the capacity to form gels with locust bean gum.</p><p>Besides xanthan lyase, <em>P. alginolyticus</em> XL-1 produces other enzymes that could be useful for xanthan modification, such as a xanthan deacetylase and an enzyme releasing uronic acid, or uronic acid-containing oligosaccharides, from xanthan lyase-modified xanthan. Since these enzymes were produced at very low titers, <em>P. alginolyticus</em> XL-1 is not a suitable production organism for xanthan-modifying enzymes. Strain XL-1 may be very useful, however, as a source of genes for heterologous production of xanthan-modifying enzymes.</p>
Plate screening methods for the detection of polysaccharase-producing microorganisms
Ruijssenaars, H.J. ; Hartmans, S. - \ 2001
Applied Microbiology and Biotechnology 55 (2001)2. - ISSN 0175-7598
Polysaccharide-degrading enzymes (polysaccharases) are widely applied in industry. One of the sources of these enzymes are polysaccharide-degrading microorganisms. To obtain such microorganisms from enrichment cultures, strain collections or gene libraries, efficient plate screening methods are required that discriminate between intact and degraded polysaccharide. This can be achieved by making use of specific physicochemical properties of the polysaccharide, such as complex formation with dyes and gelling capacity, or by the application of dye-labelled polysaccharides. This review presents a survey of plate methods based on these principles. Both theoretical and practical aspects of the methods are discussed.
Use of Life Cycle Assessment in development processes illustrated with a manure treatment system
Satter, I.H.G. ; Starmans, D.A.J. ; Willers, H.C. ; Ogink, N.W.M. ; Groot Koerkamp, P.W.G. - \ 2000
In: Proceedings of the 4th International Symposium on Biotechnology, Noordwijkerhout (NL), 10-12 April / Hartmans, S., Lens, P., - p. 157 - 160.
Performance of a thermophilic sulfate and sulfite reducing high-rate anaerobic reactor fed with methanol
Weijma, J. ; Hulshoff Pol, L.W. ; Stams, A.J.M. ; Lettinga, G. - \ 2000
In: ISEB 4 Proceedings of the 4th International Symposium on Environmental Biotechnology, Noordwijkerhout, 10-12 April 2000 / Hartmans, S., Lens, P.N.L., - p. 222 - 225.
Rates of ammonia assimilation and ammonification during composting - development of methodology
Veeken, A.H.M. ; Hanajima, D. ; Hamelers, H.V.M. - \ 2000
In: ISEB 4 Proceedings of the 4th International Symposium on Environmental Biotechnology, Noordwijkerhout, 10-12 April 2000 / Hartmans, S., Lens, P.N.L., - p. 524 - 527.
Application of redox mediators to accelerate the transformation of reactive azo dyes in anaerobic bioreactors
Zee, F.P. van der; Bouwman, R.H.M. ; Strik, D.P.B.T.B. ; Lettinga, G. ; Field, J.A. - \ 2000
In: ISEB 4 Proceedings of the 4th International Symposium on Environmental Biotechnology, Noordwijkerhout, 10-12 April 2000 / Hartmans, S., Lens, P.N.L., - p. 34 - 37.
Regulation of aspartate-derived amino-acid metabolism in Zygosaccharomyces rouxii compared to Saccharomyces cerevisiae
Sluis, C. van der; Smit, B.A. ; Hartmans, S. ; Schure, E.G. ter; Tramper, J. ; Wijffels, R.H. - \ 2000
Enzyme and Microbial Technology 27 (2000). - ISSN 0141-0229 - p. 151 - 156.
To elucidate the growth inhibitory effect of threonine, the regulation of the aspartate-derived amino-acid metabolism in Zygosaccharomyces rouxii, an important yeast for the flavor development in soy sauce, was investigated. It was shown that threonine inhibited the growth of Z. rouxii by blocking the methionine synthesis. It seemed that threonine blocked this synthesis by inhibiting the conversion of aspartate. In addition, it was shown that the growth of Z. rouxii, unlike that of Saccharomyces cerevisiae, was not inhibited by the herbicide sulfometuron methyl (SMM). From enzyme assays, it was concluded that the acetohydroxy acid synthase in Z. rouxii, unlike that in S. cerevisiae, was not sensitive to SMM. Furthermore, the enzyme assays demonstrated that the activity of threonine deaminase in Z. rouxii, like in S. cerevisiae, was strongly inhibited by isoleucine and stimulated by valine. From this work, it is clear that the aspartate-derived amino-acid metabolism in Z. rouxii only partly resembles that in S. cerevisiae. Copyright (C) 2000 Elsevier Science Inc. To elucidate the growth inhibitory effect of threonine, the regulation of the aspartate-derived amino-acid metabolism in Zygosaccharomyces rouxii, an important yeast for the flavor development in soy sauce, was investigated. It was shown that threonine inhibited the growth of Z. rouxii by blocking the methionine synthesis. It seemed that threonine blocked this synthesis by inhibiting the conversion of aspartate. In addition, it was shown that the growth of Z. rouxii, unlike that of Saccharomyces cerevisiae, was not inhibited by the herbicide sulfometuron methyl (SMM). From enzyme assays, it was concluded that the acetohydroxy acid synthase in Z. rouxii, unlike that in S. cerevisiae, was not sensitive to SMM. Furthermore, the enzyme assays demonstrated that the activity of threonine deaminase in Z. rouxii, like in S. cerevisiae, was strongly inhibited by isoleucine and stimulated by valine. From this work, it is clear that the aspartate-derived amino-acid metabolism in Z. rouxii only partly resembles that in S. cerevisiae.
The fate of sulfonated aromatic amines under aerobic and anaerobic conditions and in an aerobic bioreactor system
Tan, N.C.G. ; Leeuwen, A. van; Voorthuizen, E.M. van; Lettinga, G. ; Field, J.A. - \ 2000
In: ISEB 4 Proceedings of the 4th International Symposium on Environmental Biotechnology, Noordwijkerhout, 10-12 April 2000 / S. Hartmans and P.N.L. Lens. - [S.l.] : [s.n.], 2000. - ISBN 90-6754-594-5 - p. 567 - 570.
A novel gene encoding xanthan lyase of Paenibacillus alginolyticus strain XL-1
Ruijssenaars, H.J. ; Hartmans, S. ; Verdoes, J.C. - \ 2000
Applied and Environmental Microbiology 66 (2000). - ISSN 0099-2240 - p. 3945 - 3950.
Xanthan-modifying enzymes are powerful tools in studying structure-function relationships of this polysaccharide. One of these modifying enzymes is xanthan lyase, which removes the terminal side chain residue of xanthan. In this paper, the cloning and sequencing of the first xanthan lyase-encoding gene is described, i.e., the xalA gene, encoding pyruvated mannose-specific xanthan lyase of Paenibacillus alginolyticus XL-1. The xalA gene encoded a 100,823-Da protein, including a 36-amino-acid signal sequence. The 96,887-Da mature enzyme could be expressed functionally in Escherichia coli. Like the native enzyme, the recombinant enzyme showed no activity on depyruvated xanthan. Compared to production by P. alginolyticus, a 30-fold increase in volumetric productivity of soluble xanthan lyase was achieved by heterologous production in E. coli. The recombinant xanthan lyase was used to produce modified xanthan, which showed a dramatic loss of the capacity to form gels with locust bean gum.
Biodegradability of food-associated extracellular polysaccharides
Ruijssenaars, H.J. ; Stingele, F. ; Hartmans, S. - \ 2000
Current Microbiology 40 (2000). - ISSN 0343-8651 - p. 194 - 199.
Fungal growth on toluene : Monitoring metabolic pathways with fluorinated analogues and 19F-NMR
Prenafeta-Boldu, F.X. ; Luykx, D.M.A.M. ; Vervoort, J. ; Bont, J.A.M. de - \ 2000
In: Proceedings of the 4th International Symposium on Environmental Biotechnology : 4th International Symposium on Environmental Biotechnology, Noordwijkerhout, NL, 2000 / S. Hartmans, P. Lens. - Wageningen : [s.n.], 2000. - ISBN 90-6754-594-5 - p. 418 03:B3 - 418 03:B3.
Anaerobic production and degradation of volatile fatty acids at low temperature
Nozhevnikova, A.N. ; Rebac, S. ; Parshina, S.N. ; Kotsyurbenko, O.R. ; Holliger, C. ; Lettinga, G. - \ 2000
In: ISEB 4 Proceedings of the 4th International Symposium on Environmental Biotechnology, Noordwijkerhout, 10-12 April 2000 / Hartmans, S., Lens, P.N.L., - p. 270 - 273.
Transglycosylation by Streptococcus mutans GS-5 glucosyltransferase-D1: acceptor specificity and engineering of reaction conditions
Meulenbeld, G.H. ; Hartmans, S. - \ 2000
Biotechnology and Bioengineering 70 (2000). - ISSN 0006-3592 - p. 363 - 369.
The acceptor specificity of Streptococcus mutans GS-5 glucosyltransferase-D (GTF-D) was studied, particular the specificity toward non-saccharide compounds. Dihydroxy aromatic compounds like catechol, 4-methylcatechol, and 3-methoxycatechol were glycosylated by GTF-D with a high efficiency. Transglycosylation yields were 65°50°and 75°respectively, using 40 mM acceptor and 200 mM sucrose as glucosyl donor. 3-Methoxylcatchol was also glycosylated, though at a significantly lower rate. A number of other aromatic compounds such as phenol, 2-hydroxybenzaldehyde, 1,3-dihydroxybenzene, and 1,2-phenylethanediol were not glycosylated by GTF-D. Consequently GTF-D aromatic acceptors appear to require two adjacent aromatic hydroxyl groups. In order to facilitate the transglycosylation of less water-soluble acceptors the use of various water miscible organic solvents (cosolvents) was studied. The flavonoid catechin was used as a model acceptor. Bis-2-methoxyethyl ether (MEE) was selected as a useful cosolvent. In the presence of 15øv/v) MEE the specific catechin transglucosylation activity was increased 4-fold due to a 12-fold increase in catechin solubility. MEE (10-30␟/v) could also be used to allow the transglycosylation of catechol, 4-methylcatechol, and 3-methoxycatechol at concentrations (200 mM) otherwise inhibiting GTF-D transglycosylation activity.
Nutrients removal in three sludge types sewage treatment system
Marsman, E.H. ; Temmink, B.G. ; Reitsma, B.A.H. ; Klapwijk, A. ; Tessel, P.J. - \ 2000
In: ISEB 4 Proceedings of the 4th International Symposium on Environmental Biotechnology, Noordwijkerhout, 10-12 April 2000 / Hartmans, S., Lens, P.N.L., - p. 58 - 62.
Use of 1H NMR to visualise and characterise the structure and diffusional properties of methanogenic granular sludge
Lens, P.N.L. ; Vergeldt, F. ; Lettinga, G. ; As, H. van - \ 2000
In: ISEB 4 Proceedings of the 4th International Symposium on Environmental Biotechnology, Noordwijkerhout, 10-12 April 2000 / Hartmans, S., Lens, P.N.L., - p. 597 - 600.
High-rate sulfate reduction in bioreactors : suspended versus granular sludge
Lens, P.N.L. ; Zundert, E. van; Lettinga, G. - \ 2000
In: ISEB 4 Proceedings of the 4th International Symposium on Environmental Biotechnology, Noordwijkerhout, 10-14 April 2000 / S. Hartmans and P.N.L. Lens. - [S.l.] : [s.n.], 2000. - ISBN 90-6754-594-5 - p. 419 03:B2 - 419 03:B2.
Effect of the liquid upflow velocity on thermophilic sulphate reduction in acidifying granular sludge reactors
Lens, P.N.L. ; Korthout, D. ; Hulshoff Pol, L.W. ; Lettinga, G. - \ 2000
In: ISEB 4 Proceedings of the 4th International Symposium on Environmental Biotechnology, Noordwijkerhout, 10-12 April 2000 / S. Hartmans and P.N.L. Lens. - [S.l.] : [s.n.], 2000. - ISBN 90-6754-594-5 - p. 381 03:B2 - 381 03:B2.
Integrated mechanical, biological and physico-chemical treatment of liquid manure streams
Kalyuzhnyi, S. ; Sklyar, V. ; Epov, A. ; Arkhipchenko, I.A. ; Barbolina, I.I. ; Orlova, O. ; Nekrasova, V. ; Kevbrina, M. ; Nozhevnikova, A.N. ; Kovalev, A. ; Derikx, P.J.L. ; Klapwijk, A. - \ 2000
In: ISEB 4 Proceedings of the 4th International Symposium on Environmental Biotechnology, Noordwijkerhout, 10-14 April 2000 / Hartmans, S., Lens, P.N.L., - p. 436 - 439.
ISEB 4 Proceedings of the 4th International Symposium on Environmental Biotechnology, Noordwijkerhout, 10-12 April 2000
Hartmans, S. ; Lens, P.N.L. - \ 2000
[Wageningen] : Unknown Publisher - ISBN 9789067545945 - 608
milieubescherming - biotechnologie - afvalverwerking - environmental protection - biotechnology - waste treatment
Monooxygenase-mediated degradation of chlorinated hydrocarbons by Pseudomonas sp. DCA1
Hage, J.C. ; Hartmans, S. - \ 2000
In: Proceedings of the 4th International Symposium on Environmental Biotechnology : 4th International Symposium on Environmental Biotechnology, Noordwijkerhout, NL, 2000 / Hartmans, S., Lens, P., Wageningen : - ISBN 9067544945 - p. 13 - 16.
Quinones as final electron acceptors in anaerobic granular sludge
Cervantes, F.J. ; Velde, S. van der; Lettinga, G. ; Field, J.A. - \ 2000
In: ISEB 4 Proceedings of the 4th International Symposium on Environmental Biotechnology, Noordwijkerhout, 10-12 April 2000 / Hartmans, S., Lens, P.N.L., - p. 520 - 523.
Fate of nitrogen and phosphorus during pig slurry processing through straw filter
Barbolina, I.I. ; Arkhipchenko, I.A. ; Derikx, P.J.L. ; Klapwijk, A. - \ 2000
In: ISEB 4 Proceedings of the 4th International Symposium on Environmental Biotechnology, Noordwijkerhout, 10-12 April 2000 / Hartmans, S., Lens, P.N.L., - p. 407 - 410.
Pootgoed kan goed worden bewaard met buitenluchtkoeling
Hak, P.S. ; Hartmans, K.J. - \ 1999
Aardappelwereld 53 (1999)8. - ISSN 0169-653X - p. 31 - 33.
pootaardappelen - opslag - gasbewaring - koelen - koelsystemen - kiemrust - seed potatoes - storage - controlled atmosphere storage - cooling - cooling systems - seed dormancy
Uit onderzoek kan worden afgeleid dat de invloed van de hoogte van de bewaarpemperatuur tot medio eind november minder groot is op het kiemgedrag dan mogelijk werd aangenomen
A pyruvated mannose-specific xanthan lyase involved in xanthan degradation by Paenibacillus alginolyticus XL-1
Ruijssenaars, H.J. ; Bont, J.A.M. de; Hartmans, S. - \ 1999
Applied and Environmental Microbiology 65 (1999)6. - ISSN 0099-2240 - p. 2446 - 2452.
Enhanced (+)-catechin transglucosylating activity of Streptococcus mutans GS-5 glucosyltransferase-D due to fructose removal
Meulenbeld, G.H. ; Zuilhof, H. ; Veldhuizen, A. van; Heuvel, R.H.H. van den; Hartmans, S. - \ 1999
Applied and Environmental Microbiology 65 (1999)9. - ISSN 0099-2240 - p. 4141 - 4147.
Monooxygenase-mediated 1,2-dichloroethane degradation by Pseudomonas sp. strain DCA1
Hage, J.C. ; Hartmans, S. - \ 1999
Applied and Environmental Microbiology 65 (1999)6. - ISSN 0099-2240 - p. 2466 - 2470.
Kiemregulering bij 7 pootaardappelrassen gedurende de bewaring met behulp van Talent en de invloed daarvan op de teelt en op de consumptiedatum: (resultaten van bewaarexperimenten uitgevoerd op het PAV en teeltexperimenten op de ATO-DLO proefboerderij 'de Eest', gedurende het seizoen 1996/1997)
Hartmans, Klaasje J. - \ 1998
Wageningen : ATO-DLO (Rapport / ATO-DLO B374) - 53
Application of caraway seed constituents as spout suppressant and for control of fungal storage diseases
Hartmans, K.J. ; Oosterhaven, J. ; Gorris, L.G.M. ; Smid, E.J. - \ 1998
In: Caraway, The Genus Carum
Application of S-carvone as a potato sprout suppressant and control agent of fungal storage diseases
Hartmans, K.J. ; Oosterhaven, J. ; Smid, E.J. - \ 1998
In: Caraway The Genus Carum - p. 175 - 195.
Zilverschurft en de bewaring van aardappelen
Hartmans, K.J. ; Smid, E.J. - \ 1998
Aardappelwereld 52 (1998)3. - ISSN 0169-653X - p. 25 - 28.
plantenziekteverwekkende schimmels - solanum tuberosum - aardappelen - opslag - pootaardappelen - gewasbescherming - cultuurmethoden - oogsttijdstip - fungiciden - helminthosporium solani - plant pathogenic fungi - potatoes - storage - seed potatoes - plant protection - cultural methods - harvesting date - fungicides
Sprout growth regulation of 7 seedpotato cultivars during storage with Talent and the influence on subsequent plant growth and potato yield (ware potatoes). Results of storage experiments carried out at PAGV and field experiments conducted on the ATO-DLO experimental farm "de Eest"during the season 1996-1997 (In Dutch)
Hartmans, K.J. - \ 1998
Unknown Publisher
Potato Storage Research in the Netherlands
Oosterhaven, K. ; Hartmans, K. ; Hertog, M. ; Verdijck, G. ; Ceton, C. - \ 1998
Screening for polysaccharide-degrading micro-organisms.
Ruijssenaars, H.J. ; Wiel, L.G. van de; Hartmans, S. - \ 1998
In: New frontiers in screening for microbial biocatalysts / Kieslich, K., van der Beek, C.P., de Bont, J.A.M., van den Tweel, W.J.J., - p. 239 - 245.
Indigo formation by aromatic hydrocarbon-degrading bacteria.
O'Connor, K.E. ; Hartmans, S. - \ 1998
Biotechnology Letters 20 (1998)3. - ISSN 0141-5492 - p. 219 - 223.
A variety of aromatic hydrocarbon-degrading bacteria expressing different oxygenases were tested for their ability to produce indigo from indole. Styrene-grown cells of Pseudomonas putida S12 and CA-3 expressing styrene mono-oxygenase produced indigo at rates of 4–8 nmol min–1 mg dry wt–1. Toluene-grown cells of P. putida F1 and naphthalene-grown cells of P. putida PpG7 expressing dioxygenases formed indigo at rates of 1.5 and 2.5 nmol min–1 mg dry wt–1, respectively.
Recalcitrance of 1,1-dichloro-2,2-bis (p-chlorophenyl) ethylene to degradation by pure cultures of 1,1-diphenylethylene-degrading aerobic bacteria.
Megharaj, M. ; Hartmans, S. ; Engesser, K.H. ; Thiele, J.H. - \ 1998
Applied Microbiology and Biotechnology 49 (1998). - ISSN 0175-7598 - p. 337 - 342.
Purification and characterization of two lignin peroxidase isozymes produced by Bjerkandera sp. strain BOS55.
Have, R. ten; Hartmans, S. ; Teunissen, P.J.M. ; Field, J.A. - \ 1998
FEBS Letters 422 (1998). - ISSN 0014-5793 - p. 391 - 394.
Calculated ionisation potentials to determine the oxidation of vanillin precursors by lignin peroxidase.
Have, R. ten; Rietjens, I.M.C.M. ; Hartmans, S. ; Swarts, H.J. ; Field, J.A. - \ 1998
FEBS Letters 430 (1998). - ISSN 0014-5793 - p. 390 - 392.
In view of the biocatalytic production of vanillin, this research focused on the lignin peroxidase (LiP) catalysed oxidation of naturally occurring phenolic derivatives: O-methyl ethers, O-acetyl esters, and O-glucosyl ethers. The ionisation potential (IP) of a series of model compounds was calculated and compared to their experimental conversion by LiP, defining a relative IP threshold of approximately 9.0 eV. Based on this threshold value only the O-acetyl esters and glucosides of isoeugenol and coniferyl alcohol would be potential LiP substrates. Both O-acetyl esters were tested and were shown to be converted to O-acetyl vanillin in molar yields of 51.8 and 2.3%, respectively.
Membrane bioreactors for waste gas treatment.
Reij, M.W. ; Keurentjes, J.T.F. ; Hartmans, S. - \ 1998
Journal of Biotechnology 59 (1998). - ISSN 0168-1656 - p. 155 - 167.
This review describes the recent development of membrane reactors for biological treatment of waste gases. In this type of bioreactor gaseous pollutants are transferred through a membrane to the liquid phase, where micro-organisms degrade the pollutants. The membrane bioreactor combines the advantages of membrane devices with the clean technology of biological air purification. Two types of membrane materials can be used for gas-liquid contact: hydrophobic microporous material and dense material, such as silicone rubber. Microporous material generally has a higher permeability, but dense membranes can be advantageous in the case specific selectivity is required. Biomass is generally present as a biofilm on the membrane, but may also be suspended in the liquid phase. In a number of cases the reactor performance appears to be hampered by an unstable biofilm performance and/or by clogging of the liquid channels due to excess biomass formation. So far, membrane bioreactors for waste gas treatment have only been tested on laboratory scale. If the long-term stability of these reactors can be demonstrated, we expect membrane bioreactors to be useful tools in the treatment of gas streams containing poorly water-soluble pollutants and highly chlorinated hydrocarbons, which are difficult to treat with the conventional methods for biofiltration.
Kiemregulering bij 3 fabrieksrassen gedurende de bewaring met behulp van Talent en de invloed daarvan op de teelt en opbrengst : (resultaten van bewaarexperimenten uitgevoerd op het PAGV (Lelystad) en teeltexperimenten uitgevoerd op de proefboerderijen Kooijenburg (Rolde) en 't Kompas (Valthermond) van de Stichting Interprovinciaal Onderzoekscentrum voor de Akkerbouw, gedurende het seizoen 1994/95)
Hartmans, Klaasje J. - \ 1997
Wageningen : ATO-DLO (Rapport / ATO-DLO B295) - 42
Kiemregulering bij 4 pootaardappelrassen gedurende de bewaring met behulp van Talent en de invloed daarvan op de teelt en opbrengst bij laat pten : (resultaten van bewaarexperimenten uitgevoerd op het PAGV en de proefboerderij Westmaas en teeltexperimenten uitgevoerd op de ATO-DLO proefboerderij 'de Eest', gedurende het seizoen 1995/1996)
Hartmans, Klaasje J. - \ 1997
Wageningen : ATO-DLO (Rapport / ATO-DLO B294) - 45
Kiemregulering bij 5 late pootaardappelrassen gedurende de bewaring met behulp van Talent en de invloed daarvan op de teelt en opbrengst : (resultaten van bewaarexperimenten uitgevoerd op het PAGV en op de ATO-DLO proefboerderij 'de Eest', gedurende het seizoen 1995/1996)
Hartmans, Klaasje J. - \ 1997
Wageningen : ATO-DLO (Rapport / ATO-DLO B266) - 51
Kiemregulering bij 4 vroege pootaardappelrassen gedurende de bewaring met behulp van Talent en de invloed daarvan op de teelt en opbrengst : (resultaten van bewaarexperimenten uitgevoerd op het PAGV en de proefboerderij Westmaas en teeltexperimenten uitgevoerd op de ATO-DLO proefboerderij 'de Eest', gedurende het seizoen 1995/1996)
Hartmans, Klaasje J. - \ 1997
Wageningen : ATO-DLO (Rapport / ATO-DLO B261) - 50
Kiemregulering bij 4 pootaardappelrassen gedurende de bewaring met behulp van Talent en de invloed daarvan op de teelt en opbrengst : (resultaten van bewaarexperimenten uitgevoerd op het PAGV en de proefboerderij Westmaas en teeltexperimenten uitgevoerd op de ATO-DLO proefboerderij 'de Eest', gedurende het seizoen 1995/1996)
Hartmans, Klaasje J. - \ 1997
Wageningen : ATO-DLO (Rapport / ATO-DLO B248) - 58
Talent suppressed storage diseases at seed potatoes (in Dutch)
Hartmans, K.J. ; Hak, P.S. ; Smid, E.J. - \ 1997
Aardappelwereld 51 (1997)4. - ISSN 0169-653X - p. 19 - 21.
groeivertraging - pootaardappelen - gewasbescherming - bestrijdingsmethoden - opslag - plantenziektekunde - bewaarziekten - growth retardation - seed potatoes - plant protection - control methods - storage - plant pathology - storage disorders
Induction of maleate hydratase in Pseudomonas pseudoalcaligenes.
Werf, M.J. van der; Huybers, P. ; Tweel, W.J.J. van den; Hartmans, S. - \ 1997
World Journal of Microbiology and Biotechnology 13 (1997). - ISSN 0959-3993 - p. 279 - 282.
Isolation of a xanthan-degrading bacterium and purification of its xanthan lyase.
Ruijssenaars, H.J. ; Hartmans, S. - \ 1997
In: VII meeting on industrial applications of enzymes, Barcelona - p. 169 - 169.
Evaluation of a plate method for screening of polysaccharide-degrading micro-organisms.
Ruijssenaars, H.J. ; Hartmans, S. - \ 1997
Nederlands Tijdschrift voor Medische Microbiologie 5 (1997). - ISSN 0929-0176 - p. 45 - 46.
Screening for polysaccharase-producing micro-organisms.
Ruijssenaars, H.J. ; Wiel, L.G. van der; Hodgson, G.A. ; Hartmans, S. - \ 1997
In: 2nd Carbohydrate Bioengineering Meeting, La Rochelle, France, Programme and Abstracts - p. S9 - S9.
Biofiltration of air containing low concentrations of propene using a membrane bioreactor.
Reij, M.W. ; Hamann, E.K. ; Hartmans, S. - \ 1997
Biotechnology Progress 13 (1997). - ISSN 8756-7938 - p. 380 - 386.
Membrane bioreactor for waste gas treatment
Reij, M.W. - \ 1997
Agricultural University. Promotor(en): J.A.M. de Bont; S. Hartmans. - S.l. : Reij - ISBN 9789054856351 - 114
biotechnologie - afvoergassen - biochemie - membranen - bioreactoren - biotechnology - waste gases - biochemistry - membranes - bioreactors
Summary<p>This thesis describes the design and testing of a membrane bioreactor (MBR) for removal of organic pollutants from air. In such a bioreactor for biological gas treatment pollutants are degraded by micro-organisms. The membrane bioreactor is an alternative to other types of bioreactors for waste gas treatment, such as compost biofilters and bioscrubbers. Propene was used as a model pollutant to study the membrane bioreactor.<p>A membrane bioreactor for waste gas treatment consists of a gas and a liquid compartment, separated by a membrane. Gaseous pollutants diffuse through the membrane and are consumed by microorganisms present in the liquid phase. The organisms are supplied with water and inorganic nutrients via this liquid phase. Various membrane bioreactors described in the literature are reviewed in Chapter 2. In the work presented in this thesis, microporous hydrophobic material was selected because of its low mass transfer resistance and the availability of both sheets and fibres. For the removal of propene from air the mass transfer resistance of this type of membrane was found to be negligible (Chapter 3).<p>The propene-degrading bacterium <em>Xanthobacter</em> Py2 was shown to form biofilms in membrane bioreactors. Continuous propene removal by biofilms of <em>Xanthobacter</em> Py2 was demonstrated in both flat sheet reactors and hollow-fibre reactors. In both configurations the biofilms are situated on the membrane in the liquid phase. Propene consumption rates could be described quite accurately with the computer programme BIOSIM, that describes simultaneous diffusion and reaction in a biolayer (Chapter 3).<p>During continuous operation of hollow-fibre reactors at inlet concentrations of 0.5 to 6 gram propene per m <sup>3</SUP>, the propene conversion decreased after several weeks (Chapter 4). Clogging of the fibres by excess biomass formation and acidification due to ammonium oxidation, were identified as possible causes. However, when both clogging and ammonium oxidation were prevented, the propene conversion still decreased in time.<p>Apparently other factors than clogging and nitrification affect the long-term performance of biofilms of <em>Xanthobacter</em> Py2, growing In an MBR. These factors might be Identified with new methods for biofilm analysis, which allow the localization of activity within the biofilm.<p>According to the Dutch emission standards, hydrocarbons such as propene, in offgas have to be reduced to less than 150 mg m <sup>-3</SUP>. In Chapter 5, two propenedegrading strains were compared for their ability to degrade such low concentrations of propene and the faster growing strain, <em>Xanthobacter</em> Py2, was selected. At a concentration of 300 to 600 mg m <sup>-3</SUP>in the gas phase, a 20 days startup period was required for biofilm formation. Once the biofilm had been established, the amount of active biomass adapted to the amount of propene available Within several days. Propene could be removed continuously from air at a concentration of 15 to 50 mg m <sup>-3</SUP>in the gas phase without supplying other organic nutrients to the microbial population (Chapter 5).<p>Besides the removal of poorly water soluble pollutants like propene, the membrane bioreactor is also suitable for the removal of pollutants that result in acidification, such as chlorinated hydrocarbons. Therefore, in Chapter 6 the biodegradation of trichloroethene (TCE) by <em>Xanthobacter</em> Py2 was tested during growth on propene in a stirred vessel. The aerobic biodegradation of TCE is difficult because of toxic intermediates that are formed. With <em>Xanthobacter</em> Py2 continuous cometabolic degradation of TCE was shown to be feasible with concentrations up to 206 μM in the liquid phase. The amount of TCE that could be degraded, depended on the TCE concentration and ranged from 0.03 to 0.34 grams of TCE per gram of biomass.<p>Membrane bioreactors for gas-liquid contact have several potential applications. They are suitable for the removal of poorly soluble pollutants from air because of their large gas-liquid interface and small mass transfer resistance. Especially if biodegradation of a poorly soluble pollutant results in acidification, the membrane bioreactor might be a unique tool, since the acidic product can be removed via the liquid phase. Other applications might be the removal of highly chlorinated hydrocarbons from air by an aerobic or a combined anaerobic/aerobic: process, as was recently suggested in literature. Membrane bioreactors may also be useful tools in biofilm research, because of easy handling and processing of biofilm samples, excellent oxygen transfer properties and the possibility to apply counter gradients.
Indigo formation by microorganisms expessing styrene monooxygenase activity.
O'Connor, K.E. ; Dobson, A.D.W. ; Hartmans, S. - \ 1997
Applied and Environmental Microbiology 63 (1997). - ISSN 0099-2240 - p. 4287 - 4291.
Biodegradation kinetics in relation to the removal of low contaminant concentrations from waste streams.
Hartmans, S. ; Hage, K.C. ; O'Connor, K.E. ; Reij, M.W. - \ 1997
In: Proc. Part II, 3rd Int. Symp. Env. Biotech., Oostende, Belgium, Eds. H. Verachtert and W. Verstraete - p. 471 - 474.
Transglycosylation of alcohols with glycosyltransferases.
Hartmans, S. ; Meulenbeld, G.H. ; Heuvel, R.H.H. van den; Pijnenburg, J.P.M. - \ 1997
In: 2nd Carbohydrate Bioengineering Meeting,La Rochelle, France, Programme and Abstracts - p. S9 - S9.
Biological waste gas treatment: kinetics and reactors.
Hartmans, S. - \ 1997
Mededelingen - Universiteit Gent, Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen 62 (1997). - ISSN 1373-7503 - p. 1501 - 1504.
Membrane bioreactor for the removal of chlorinated compounds from groundwater.
Hage, J.C. ; Hartmans, S. - \ 1997
Nederlands Tijdschrift voor Medische Microbiologie 5 (1997). - ISSN 0929-0176 - p. 37 - 38.
Interference of peptone and tyrosine with the lignin peroxidase assay.
Have, R. ten; Hartmans, S. ; Field, J.A. - \ 1997
Applied and Environmental Microbiology 63 (1997)5. - ISSN 0099-2240 - p. 3301 - 3303.
Kiemregulering bij 9 pootaardappelrassen gedurende de bewaring met behulp van Talent en de invloed daarvan op de teelt en opbrengst : (resultaten van bewaarexperimenten uitgevoerd op het PAGV en de proefboerderij Westmaas en teeltexperimenten uitgevoerd op de ATO-DLO proefboerderij 'de Eest', gedurende het seizoen 1994/1995)
Hartmans, Klaasje J. - \ 1996
Wageningen : ATO-DLO (Rapport / ATO-DLO B187) - 55
Kiemregulering bij 4 pootaardappelrassen gedurende de bewaring met behulp van Talent en de invloed daarvan op de teelt en opbrengst : (resultaten van bewaarexperimenten uitgevoerd op het PAGV en de proefboerderij Westmaas en teeltexperimenten uitgevoerd op de ATO-DLO proefboerderij 'de Eest', gedurende het seizoen 1994/1995)
Hartmans, Klaasje J. - \ 1996
Wageningen : ATO-DLO (Rapport / ATO-DLO B176) - 50
Kiemremming bij consumptieaardappel (Agria) met behulp van Talent formuleringen : resultaten van een bewaarexperiment uitgevoerd op de ATO-DLO Proefboerderij "De Eest" (NOP) gedurende het bewaarseizoen 1994-1995
Hartmans, K.J. ; Buitelaar, N. - \ 1996
Wageningen : ATO-DLO (Rapport / ATO-DLO B207) - 34
Kiemremming bij een 10-tal aardappelrassen met behulp van Talent : resultaten van een bewaarexperiment uitgevoerd op de ATO-DLO Proefboerderij "De Eest" (NOP) gedurende het bewaarseizoen 1994-1995
Hartmans, K.J. ; Buitelaar, N. - \ 1996
Wageningen : ATO-DLO (Rapport / ATO-DLO B199) - 29
Kiemregulering bij 4 fabrieksrassen gedurende de bewaring met behulp van Talent en de invloed daarvan op de teelt en opbrengst : (resultaten van bewaarexperimenten uitgevoerd op het PAGV (Lelystad) en teeltexperimenten uitgevoerd op de proefboerderijen Kooijenburg (Rolde) en 't Kompas (Valthermond) van de Stichting Interprovinciaal Onderzoekscentrum voor de Akkerbouw, gedurende het seizoen 1994/95)
Hartmans, Klaasje J. - \ 1996
Wageningen : ATO-DLO (Rapport / ATO-DLO B197) - 46
Kiemregulering bij 4 pootaardappelrassen gedurende de bewaring met behulp van Talent en de invloed daarvan op de teelt en opbrengst bij laat poten : resultaten van bewaarexperimenten uitgevoerd op het PAGV en de proefboerderij Westmaas en teeltexperimenten uitgevoerd op de ATO-DLO proefboerderij 'de Eest', gedurende het seizoen 1994/1995)
Hartmans, Klaasje J. - \ 1996
Wageningen : ATO-DLO (Rapport / ATO-DLO B193) - 43
Sprout growth regulation during storage of seed potatoes with Talent (in Dutch)
Hartmans, K.J. - \ 1996
Aardappelwereld (1996)11. - ISSN 0169-653X - p. 21 - 23.
fungiciden - kiemremmers - pesticiden - gewasbescherming - pootaardappelen - kiemremming - fungicides - germination inhibitors - pesticides - plant protection - seed potatoes - sprout inhibition
S-carvone inhibits the wound healing of potato tubers temporarily
Oosterhaven, J. ; Hartmans, K.J. - \ 1996
In: Supplement to Plant Physiology, Abstr. of Plant Biology '96, ASPP meeting San Antonio, USA, Abstract nr. J513: 122
Temporary inhibition of the wound healing of potato tubers by S-carvone
Oosterhaven, J. ; Hartmans, K.J. - \ 1996
In: Abstracts of the 13th triennial conference of the EAPR 1996, Veldhoven, NL, July 14-19: 640-641
Food grade polysaccharides.
Hartmans, S. - \ 1996
In: Abstract NBC 6th Congr. Amsterdam, The Netherlands (1996) W-1
Screening for exo-polysaccharide degrading bacteria.
Ruijssenaars, H.J. ; Hartmans, S. - \ 1996
In: Symp. on New frontiers in screening for microbial biocatalysts. Ede, The Netherlands (1996) 66 P29
A screening method for polysaccharide degrading microorganisms.
Ruijssenaars, H.J. ; Hodgson, G.A. ; Hartmans, S. - \ 1996
In: Abstract NBC 6th Congr. Amsterdam, The Netherlands (1996) PE-5
Formation of chiral styrene oxides and 2-phenylpropionic acid.
Hartmans, S. ; Nöthe, Chr. ; Marconi, A.M. - \ 1996
In: Abstract NBC 6th Congr. Amsterdam, The Netherlands (1996) PH-11
Biofilms in membrane bioreactors.
Reij, M.W. ; Hartmans, S. - \ 1996
In: Abstract NBC 6th Congr. Amsterdam, The Netherlands (1996) W-20
Peroxidase mediated biotransformations useful in the biocatalytic production of vanillin.
Have, R. ten; Hartmans, S. ; Field, J.A. - \ 1996
In: Abstract NBC 6th Congr. Amsterdam, The Netherlands (1996) PH-13
Propene removal from synthetic waste gas using a hollow-fibre membrane bioreactor.
Reij, M.W. ; Hartmans, S. - \ 1996
Applied Microbiology and Biotechnology 45 (1996). - ISSN 0175-7598 - p. 730 - 736.
Prevention of clogging in a biological trickle-bed reactor removing toluene from contaminated air.
Weber, F.J. ; Hartmans, S. - \ 1996
Biotechnology and Bioengineering 50 (1996). - ISSN 0006-3592 - p. 91 - 97.
Tijdelijke kiemremming bij 4 pootaardappelrassen gedurende de bewaring met behulp van het carvonhoudende middel D 4024 en de invloed daarvan op de teelt en opbrengst : (resultaten van bewaarexperimenten uitgevoerd op het PAGV en teeltexperimenten uitgevoerd op de ATO-DLO proefboerderij 'de Eest', gedurende het seizoen 1993/1994)
Hartmans, Klaasje J. - \ 1995
Wageningen : ATO-DLO (Rapport / ATO-DLO B162) - 39
The use of carvone in agriculture: sprout suppression of potatoes and antifungal activity against potato tubers and other plant diseases
Hartmans, K.J. ; Diepenhorst, P. ; Bakker, W. ; Gorris, L.G.M. - \ 1995
Industrial Crops and Products 4 (1995)1. - ISSN 0926-6690 - p. 3 - 13.
The monoterpene S-carvone inhibits wound healing of wounded potato tuber tissue
Oosterhaven, J. ; Hartmans, K.J. ; Scheffer, J.J.C. ; Plas, L.H.W. van der - \ 1995
Physiologia Plantarum 93 (1995). - ISSN 0031-9317 - p. 225 - 232.
Inhibition of potato sprout growth by carvone enantiomers and their bioconversion in sprouts
Oosterhaven, J. ; Hartmans, K.J. ; Scheffer, J.J.C. - \ 1995
Potato Research 38 (1995)2. - ISSN 0014-3065 - p. 219 - 230.
Membrane bioreactor with a porous hydrophobic membrane as a gas-liquid contactor for waste gas treatment.
Reij, M.W. ; Gooijer, K.D. de; Bont, J.A.M. de; Hartmans, S. - \ 1995
Biotechnology and Bioengineering 45 (1995). - ISSN 0006-3592 - p. 107 - 115.
Toluene : biological waste-gas treatment, toxicity and microbial adaptation
Weber, F.J. - \ 1995
Agricultural University. Promotor(en): J.A.M. de Bont; S. Hartmans. - S.l. : Weber - ISBN 9789054854340 - 170
materialen - biodegradatie - tolueen - microbiële afbraak - gassen - conservering - afval - technologie - afvalverwerking - kwaliteit - recycling - milieu - materials - biodegradation - toluene - microbial degradation - gases - conservation - wastes - technology - waste treatment - quality - environment
<p>Due to the increasing stringent legislation concerning the emission of volatile organic compounds, there is nowadays a growing interest to apply biological waste-gas treatment techniques for the removal of higher concentrations of specific contaminants from waste gases. Fluctuations in the contaminant concentrations can strongly affect the performance of bioreactors used for the treatment of waste-gas streams. Temporary high concentrations can be toxic for the microorganisms in the reactor, resulting in inactivation of the system. Furthermore, for a reliable operation the design of the reactor should be based on the peak concentrations in the waste gas, which is not an economically favourable situation. Therefore, it would be desirable to buffer the fluctuations in the contaminant concentration by means of an adsorbent, so that a constant supply of contaminants to the bioreactor can be achieved. The buffer capacity of a number of activated carbons and other adsorbents was tested (Chapter 2). Using one selected type of activated carbon it was demonstrated that fluctuations between 0 and 1000 mg toluene per m <sup><font size="-1">3</font></SUP>could be transformed to an average value of about 300 mg/m <sup><font size="-1">3</font></SUP>, which was subsequently completely degraded in a biofilter. Without an activated-carbon column significant amounts of toluene were not degraded in the biofilter when the inlet concentration was 1000 mg/m3,<p>A disadvantage of trickie-bed reactors for biological waste-gas treatment is the reduction in reactor performance which is sometimed observed due to the formation of an excessive amount of biomass resulting in clogging. By limiting the amount of nutrients available for biomass formation it was attempted to prevent clogging of the reactor (Chapter 3). As a consequence of this nutrient limitation a reduced removal rate of toluene was observed. However, when a fungal culture was used to inoculate the reactor, the toluene removal rate under nutrient limiting conditions was almost twice as high. Over a period of 375 days an average removal rate of 27 g-C/(m <sup><font size="-1">3</font></SUP>h) was obtained with this fungal culture. These results clearly show that, even under non-sterile conditions, inoculation of the reactor with a specific starter culture can influence the reactor performance over a prolonged period of time. From the carbon balance over the reactor and the nitrogen availability it was concluded that under these nutrient-limited conditions large amounts of carbohydrates are formed. Even under nutrientlimited conditions the biomass content (including extracellular polysaccharides and other polymers) of the reactor increased, which eventually can result in clogging of the reactor. In order to prevent clogging eventually biomass has to be removed regularly from the reactor. We therefore studied the application of a NaOH- wash to remove excess biomass. Using regular NaOH-washes an average toluene removal rate of 35 g-C/(m <sup><font size="-1">3</font></SUP>h) was obtained with a mixed culture of bacteria. After about 50 days there was no longer a net increase in the biomass content of the reactor. The amount of biomass which was formed in the reactor equalled the amount removed by the NaOH-wash Under these conditions it should be possible to maintain a high toluene removal rate without clogging of the reactor taking place for a long period of time.<p>From a biofilter used for the removal of toluene from waste gases we have isolated the fungus, <em>Cladosporium sphaerospermum,</em> which is able to grow on toluene as the sole source of carbon and energy (Chapter 4). To our knowledge this is the first report of toluene catabolism by an eukaryotic microorganism. The oxygen-consumption rates as well as the measured enzyme activities of toluenegrown <em>C.</em><em>sphaerospermum</em> indicate that toluene is degraded by an initial attack on the methyl group.<p>The toxicity of various pollutants in a waste-gas stream for microorganisms could limit the application of biological waste-gas treatment techniques. Especially compounds, with a good solubility in water can be expected to accumulate in the water-phase of the reactor during the start-up period. This accumulation can result in the inactivation of the biomass in the reactor as the contaminant concentrations reach toxic levels. The toxicity of various volatile organic compounds frequently present as contaminants in waste gases has been determined (Chapter 5). For both the Gram-positive <em>Rhodococcus</em> S5 and the Gram-negative <em>Pseudomonas</em> S12 the toxicity was assessed as the concentration which reduced the growth rate of the bacterium with 50%. No significant differences were observed between the IC50% values for these two bacteria. A relationship between the toxicity and hydrophobicity of various substituted benzene compounds was observed.<p>Surprisingly, one of the selected bacteria, <em>Pseudomonas putida</em> S12 was able to adapt to the presence of high concentrations of contaminants. This adaptation resulted in the capacity of this strain to grow in the presence of supersaturating amounts of toluene (Chapter 6).<p>In general, the toxicity of organic solvents is caused by the accumulation of these lipophilic solvents in the membrane lipid bilayer, affecting structural and functional properties of the membrane. The accumulation of solvents in the cell membrane can affect both the membrane fluidity and the bilayer stability. The physico-chemical effects of alkanols, alkanes and other hydrocarbons on biomembranes are summarized in Chapter 8. Although organic solvents can be highly toxic for microorganisms, some microorganisms are able to grow in the presence of concentrations of these solvents which are generally toxic (Chapter 8).<p><em>P. putida</em> S12 and two other solvent tolerant <em>P. putida</em> strains reacted to toxic concentrations of toluene by accumulating trans unsaturated fatty acids in the membrane instead of the <em>cis</em> isomers. This higher <em>trans</em> / <em>cis</em> ratio of the unsaturated fatty acids in toluene-adapted cells resulted a higher lipid-ordering since the gel to liquid-crystalline transition temperature was about 7-9 °C higher compared to the non- adapted cells. This <em>cis</em> / <em>trans</em> isomerization of fatty acids is probably a mechanism to very quickly compensate for the increase in membrane fluidity, and destabilization of the bilayer structure caused by toluene accumulating in the membrane (Chapter 7 & 8). Apart from changes in the fatty acid composition also changes in the phospholipid composition were observed when the organism was grown in the presence of toluene. The decreased incorporation of phosphaticlylethanolamine and the increased incorporation of diphosphatidylethanolamine (cardiolipin) are expected to prevent the formation of non-bilayer phospholipids configurations which might be caused by toluene (Chapter 8).<p>In Chapter 9 the results presented in this thesis are discussed in relation to biotechnological applications.
Use of activated carbon as a buffer in biofiltration of waste gases with fluctuating concentrations of toluene.
Weber, F.J. ; Hartmans, S. - \ 1995
Applied Microbiology and Biotechnology 43 (1995). - ISSN 0175-7598 - p. 365 - 369.
Possible regulatory role for nonaromatic carbon sources in styrene degradation by Pseudomonas putida CA-3.
O'Connor, K. ; Buckley, C.M. ; Hartmans, S. ; and Dobson, A.D.W. - \ 1995
Applied and Environmental Microbiology 61 (1995). - ISSN 0099-2240 - p. 544 - 548.
Inhibitory effect of S-carvone on wound healing of potato tuber tissue.
Oosterhaven, K. ; Hartmans, K.J. ; Scheffer, J.J.C. ; Plas, L.H.W. van der - \ 1995
Physiologia Plantarum 93 (1995). - ISSN 0031-9317 - p. 225 - 232.
S-Carvone inhibits phenylalanine ammonia lyase (PAL) activity and suberization during wound healing of potato tubers.
Oosterhaven, K. ; Hartmans, K.J. ; Scheffer, J.J.C. ; Plas, L.H.W. van der - \ 1995
Journal of Plant Physiology 146 (1995). - ISSN 0176-1617 - p. 288 - 294.
Effect of maleate counterion on malease activity: production of D-malate in a crystal-liquid two-phase system.
Werf, M.J. van der; Hartmans, S. ; Tweel, W.J.J. van den - \ 1995
Enzyme and Microbial Technology 17 (1995). - ISSN 0141-0229 - p. 430 - 436.
Permeabilization and lysis of Pseudomonas pseudoalcaligenes cells by Triton X-100 for efficient production of D-malate.
Werf, M.J. van der; Hartmans, S. ; Tweel, W.J.J. van den - \ 1995
Applied Microbiology and Biotechnology 43 (1995). - ISSN 0175-7598 - p. 590 - 594.
Continuous degradation of trichloroethylene by Xanthobacter sp. strain Py2 during growth on propene.
Reij, M.W. ; Kieboom, J. ; Bont, J.A.M. de; Hartmans, S. - \ 1995
Applied and Environmental Microbiology 61 (1995). - ISSN 0099-2240 - p. 2936 - 2942.
Microbial degradation of styrene.
Hartmans, S. - \ 1995
In: Biotransformations: microbial degradation of health risk compounds, Ved Pal Singh (ed.). Elsevier Sci. Publ., Amsterdam - p. 227 - 238.
Microbial aspects of biological waste gas treatment.
Hartmans, S. - \ 1995
In: Abstract 7th European Congr. on Biotechnology. Nice, France. Abstract book 4 (1995) 44 JEC 203
Microbial degradation of vinyl chloride.
Hartmans, S. - \ 1995
In: Biotransformations: microbial degradation of health risk compounds, Ved Pal Singh (ed.). Elsevier Sci. Publ., Amsterdam - p. 239 - 248.
Enzymology and stereochemistry of styrene oxidation.
Hartmans, S. ; Nöthe, C. ; Marconi, A.M. - \ 1995
BioSpektrum (1995). - ISSN 0947-0867 - p. 78 - PB005.
Enzymology and stereochemistry of styrene oxidation.
Hartmans, S. ; Nöthe, Chr. ; Bont, J.A.M. de - \ 1995
In: Abstract 7th European Congr. on Biotechnology. Nice, France. Abstract book 2 (1995) 104 MAP 215
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