Genome analyses of the carboxydotrophic sulfate-reducers Desulfotomaculum nigrificans and Desulfotomaculum carboxydivorans and reclassification of Desulfotomaculum caboxydivorans as a later synonym of Desulfotomaculum nigrificans
Visser, M. ; Parshina, S.N. ; Alves, J.I. ; Sousa, D.Z. ; Pereira, I.A.C. ; Muyzer, G. ; Kuever, J. ; Lebedinsky, A.V. ; Koehorst, J.J. ; Worm, P. ; Plugge, C.M. ; Schaap, P.J. ; Goodwin, L.A. ; Lapidus, A. ; Kyrpides, N.C. ; Detter, J.C. ; Woyke, T. ; Chain, P. ; Davenport, K.W. ; Spring, S. ; Rohde, M. ; Klenk, H.P. ; Stams, A.J.M. - \ 2014
Standards in Genomic Sciences 9 (2014)3. - ISSN 1944-3277 - p. 655 - 675.
reducing bacterium - sp nov. - sequence - growth - classification - hydrogenase - evolution - standard - archaea - system
Desulfotomaculum nigrificans and D. carboxydivorans are moderately thermophilic members of the polyphyletic spore-forming genus Desulfotomaculum in the family Peptococcaceae. They are phylogenetically very closely related and belong to ‘subgroup a’ of the Desulfotomaculum cluster 1. D. nigrificans and D. carboxydivorans have a similar growth substrate spectrum; they can grow with glucose and fructose as electron donors in the presence of sulfate. Additionally, both species are able to ferment fructose, although fermentation of glucose is only reported for D. carboxydivorans. D. nigrificans is able to grow with 20% carbon monoxide (CO) coupled to sulfate reduction, while D. carboxydivorans can grow at 100% CO with and without sulfate. Hydrogen is produced during growth with CO by D. carboxydivorans. Here we present a summary of the features of D. nigrificans and D. carboxydivorans together with the description of the complete genome sequencing and annotation of both strains. Moreover, we compared the genomes of both strains to reveal their differences. This comparison led us to propose a reclassification of D. carboxydivorans as a later heterotypic synonym of D. nigrificans
Effect of sulfate on methanogenic communities that degrade unsaturated and saturated long-chain fatty acids (LCFA)
Sousa, D. de; Alves, J.I. ; Alves, M.M. ; Smidt, H. ; Stams, A.J.M. - \ 2009
Environmental Microbiology 11 (2009)1. - ISSN 1462-2912 - p. 68 - 80.
propionate-oxidizing bacterium - methane-producing bacteria - anaerobic granular sludge - nov sp-nov - gen-nov - reducing bacterium - uasb reactors - microbial diversity - pure culture - waste-water
Anaerobic bacteria involved in the degradation of long-chain fatty acids (LCFA), in the presence of sulfate as electron acceptor, were studied by combined cultivation-dependent and molecular techniques. The bacterial diversity in four mesophilic sulfate-reducing enrichment cultures, growing on oleate (C(18:1), unsaturated LCFA) or palmitate (C(16:0), saturated LCFA), was studied by denaturing gradient gel electrophoresis (DGGE) profiling of polymerase chain reaction (PCR)-amplified 16S rRNA gene fragments. These enrichment cultures were started using methanogenic inocula in order to assess the competition between methanogenic communities and sulfate-reducing bacteria. Phylogenetic affiliation of rRNA gene sequences corresponding to predominant DGGE bands demonstrated that members of the Syntrophomonadaceae, together with sulfate reducers mainly belonging to the Desulfovibrionales and Syntrophobacteraceae groups, were present in the sulfate-reducing enrichment cultures. Subculturing of LCFA-degrading methanogenic cultures in the presence of sulfate resulted in the inhibition of methanogenesis and, after several transfers, archaea could no longer be detected by real-time PCR. Competition for hydrogen and acetate was therefore won by sulfate reducers, but acetogenic syntrophic bacteria were the only known LCFA-degrading organisms present after subculturing with sulfate. Principal component analysis of the DGGE profiles from methanogenic and sulfate-reducing oleate- and palmitate-enrichment cultures showed a greater influence of the substrate than the presence or absence of sulfate, indicating that the bacterial communities degrading LCFA in the absence/presence of sulfate are rather stable
Sulfate Reduction at pH 4 During the Thermophilic (55 degrees C) Acidification of Sucrose in UASB Reactors
Lopes, S.I.C. ; Capela, M.I. ; Dar, S.A. ; Muyzer, G. ; Lens, P.N.L. - \ 2008
Biotechnology Progress 24 (2008)6. - ISSN 8756-7938 - p. 1278 - 1289.
acid-mine drainage - gradient gel-electrophoresis - anaerobic granular sludge - in-situ hybridization - mill waste-water - sp-nov - reducing bacterium - metal fractionation - bioreactor - sulfur
Continuous sulfate reduction at pH 4.0 was demonstrated in a pH controlled thermophilic (55 degrees C) upflow anaerobic sludge bed reactor fed with sucrose at a COD/SO42- ratio of 0.9 and an organic loading rate of 0.8 and 1.9 gCOD (l(reactor) d)(-1) for a period of 78 days. A near v complete sulfate reduction efficiency was achieved throughout the reactor run, corresponding to sulfate removal rates of 0.91 and 1.92 g (l(reactor) d)(-1) at sulfate loading rates of 0.94 and 2 g (l(reactor) d)(-1), respectively, by keeping the sulfide concentration below 20 mg l(-1) due to stripping with nitrogen gas. Acidification was always complete and acetate was the only, degradation intermediate left in the effluent, which did not exceed 180 mgCOD l(-1) in pseudo-stationary states. The sludge was well retained ill the reactor and kept its granular form. A, Cu, Se, and Mo accumulated in the sludge, whereas Co, Ni, Fe, and Mn leached from the sludge, despite their continuous supply to the reactor via the influent. The bacterial diversity in the reactor sludge at the end of the reactor run was low and the culture was dominated by one acidifying species, resembling Thermoanaerobacterium sp., and one sulfate reducing species, resembling Desulfotomaculum sp.
Bioconversion of Selenate in Methanogenic Anaerobic Granular Sludge
Astratinei, V. ; Hullebusch, E.D. van; Lens, P.N.L. - \ 2006
Journal of Environmental Quality 35 (2006). - ISSN 0047-2425 - p. 1873 - 1883.
soluble selenium removal - bacillus sp sf-1 - elemental selenium - sequential extraction - reducing bacterium - toxic metals - reduction - speciation - oxyanions - reactor
The capacity of anaerobic granular sludge to remove selenate from contaminated wastewater was investigated. The potential of different types of granular sludge to remove selenate from the liquid phase was compared to that of suspended sludge and contaminated soil and sediment samples. The selenate removal rates ranged from 400 to 1500 µg g VSS¿1 h¿1, depending on the source of biomass, electron donor, and the initial selenate concentration. The granular structure protects the microorganisms when exposed to high selenate concentrations (0.1 to 1 mM). Anaerobic granular sludge "Eerbeek," originating from a UASB reactor treating paper mill wastewater, removed about 90, 50, and 36% of 0.1, 0.5, and 1 mM of Se, respectively, from the liquid phase when incubated with 20 mM lactate at 30°C and pH 7.5. Selenite, elemental Se (Seo), and metal selenide precipitates were the conversion products. Enrichments from the anaerobic granular sludge "Eerbeek" were able to convert 90% of the 10-mM selenate to Seo at a rate of 1505 µg Se(VI) g cells¿1 h¿1, a specific growth rate of 0.0125 g cells h¿1, and a yield of 0.083 g cells mg Se¿1. Both microbial metabolic processes (e.g dissimilatory reduction) as well as microbially mediated physicochemical mechanisms (adsorption and precipitation) contribute to the removal of selenate from the Se-containing medium
High rate sulfate reduction in a submerged anaerobic membrane bioreactor (SAMBaR) at high salinity
Vallero, M.V.G. ; Lettinga, G. ; Lens, P.N.L. - \ 2005
Journal of Membrane Science 253 (2005)1-2. - ISSN 0376-7388 - p. 217 - 232.
methanogenic bacteria - thermophilic sulfate - waste-water - reducing bacterium - sulfite reduction - sp-nov - reactor - acetate - environments - degradation
Sulfate reduction in salt rich wastewaters (50 g NaCl L¿1 and 1 g MgCl2·6H2O L¿1; conductivity 60¿70 mS cm¿1) was investigated in a 6 L submerged anaerobic membrane bioreactor (SAMBaR) and inoculated solely with the halotolerant sulfate reducing bacterium Desulfobacter halotolerans. The SAMBaR was fed with acetate and ethanol at organic loading rates up to 14 g COD L¿1 day¿1 in excess of sulfate (COD/SO42¿ of 0.5) and operated at pH 7.2 ± 0.2 and a hydraulic retention time (HRT) from 8 to 36 h. A sulfate reduction rate up to 6.6 g SO42¿ L¿1 day¿1 was achieved in the SAMBaR operating at a flux of 17.1 L m¿2 h¿1, which resulted in a HRT of 9 h including the backflow of permeate used for backflushing. The fairly constant very high specific sulfate reduction rate of 5.5 g SO42¿ g VSS¿1 day¿1 showed that the performance of the SAMBaR was limited by the low amount of biomass (0.85 g VSS L¿1) present in the reactor at the end of the experiment. It was shown that sulfate reducing submerged anaerobic membrane bioreactors can be operated over extended periods of time without chemical cleaning of the membranes at a certain fixed flux if this flux is substantially below the nominal critical flux determined experimentally (18¿21 L m¿2 h¿1). Intermittent operation as well as backflush of the membranes were shown to slow the fouling in the membranes. Frequent backflush (e.g. 1 min each 10 min) is the suggested operational strategy to minimize fouling in anaerobic MBRs.
Methanol utilization in defined mixed cultures of thermophilic anaerobes in the presence sulfate
Goorissen, H.P. ; Stams, A.J.M. ; Hansen, T.A. - \ 2004
FEMS microbiology ecology 49 (2004)3. - ISSN 0168-6496 - p. 489 - 494.
sp-nov - reducing bacterium - reactor - reduction - hydrogen - sulfide - strains
We studied thermophilic sulfate reduction with methanol as electron donor in continuous cultures. Mixed cultures of selected microorganisms were used, representing different methanol degrading pathways followed by various trophic groups of microorganisms. Our results show that direct competition for methanol between a homoacetogen, Moorella thermoautotrophica, and a sulfate reducer, Desulfotomaculum kuzrietsovii, is in favour of the sulfate reducer due to its affinity for methanol. Methanogenesis as a result of interspecies hydrogen transfer between D. kuznetsovii and a hydrogen-consuming methanogenic archaeon, Methanothermobacter thermoautotrophicus occurred only below 5 mM total sulfide. A similar result was obtained when M. thermoautotrophica was grown on methanol in the presence of Mb. thermoautotrophicus. Interestingly, D. kuznetsovii could coexist with a non-methanolutilizing sulfate reducer (Thermodesulfovibrio species). Our data show that it is possible to maintain a dominant sulfate-reducing process with methanol as electron donor at 60 degreesC in mixed continuous cultures. (C) 2004 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.