Increase of power output by change of ion transport direction in a plant microbial fuel cell
Timmers, R.A. ; Strik, D.P.B.T.B. ; Hamelers, H.V.M. ; Buisman, C.J.N. - \ 2013
International Journal of Energy Research 37 (2013)9. - ISSN 0363-907X - p. 1103 - 1111.
long-term performance - bioelectrochemical systems - exchange membranes - electrolysis cells - iron reduction - rice plants - electricity - cathode - rhizodeposits - generation
The plant microbial fuel cell (PMFC) is a technology for the production of renewable and clean bioenergy based on photosynthesis. To increase the power output of the PMFC, the internal resistance (IR) must be reduced. The objective of the present study was to reduce the membrane resistance by changing the transport direction of cations in the direction of the established concentration gradient. Two setups, a MFC and PMFC, were designed with one anode and two cathode compartments to demonstrate the effect of changing the transport direction. This design allowed changing the direction of transport of cations by switching the cathode compartment that functions as cathode. The change between cathode 1 and cathode 2 enhanced the power output of the PMFC by 398%. More specifically, after changing transport direction, the increase in power output was due to the reduction of IR (normalized to membrane area) from 4.3 O m2mem to 1.2 O m2mem in the PMFC. Consecutive changes of cathodes resulted in an increase of generated power with cathode 1 while this power decreased for cathode 2. During the consecutive changes, the average power output remained constant 0.0362¿±¿0.0005 W m-2mem; this was 246% higher than the initial power output with cathode 1
Electricity generation by a novel design tubular plant microbial fuel cell
Timmers, R.A. ; Strik, D.P.B.T.B. ; Hamelers, H.V.M. ; Buisman, C.J.N. - \ 2013
Biomass and Bioenergy 51 (2013). - ISSN 0961-9534 - p. 60 - 67.
exchange membranes - iron reduction - rice plants - rhizodeposits - performance - resistance - transport - bacteria
The tubular plant microbial fuel cell was designed to increase the feasibility of this technology. To test the new setup two anode materials were investigated, namely a graphite felt and graphite granules. The average power output based on membrane area was 10 mW m-2 for felt, and 12 mW m-2 for graphite granules. The corresponding mass and volume power densities for the felt were 15 and 69 times greater than for the granules. This showed that a decrease in the use of anode electrode material is possible while achieving comparable power outputs per square meter of membrane. These findings make future applications of the plant microbial fuel cell technology more feasible due to costs reduction per kWh. Furthermore, this PMFC design could be likely applied into soils without the need to excavate the topsoil.2
Insect egg deposition induces indirect defense and epicuticular wax changes in Arabidopsis thaliana
Blenn, B. ; Bandoly, M. ; Küffner, A. ; Otte, T. ; Geiselhardt, S. ; Fatouros, N.E. ; Hilker, M. - \ 2012
Journal of Chemical Ecology 38 (2012)7. - ISSN 0098-0331 - p. 882 - 892.
furcifera horvath homoptera - plant cuticular waxes - whitebacked planthopper - eceriferum mutants - trissolcus-basalis - pierid butterflies - nezara-viridula - host location - up-regulation - rice plants
Egg deposition by the Large Cabbage White butterfly Pieris brassicae on Brussels sprouts plants induces indirect defense by changing the leaf surface, which arrests the egg parasitoid Trichogramma brassicae. Previous studies revealed that this indirect defense response is elicited by benzyl cyanide (BC), which is present in the female accessory reproductive gland (ARG) secretion and is released to the leaf during egg deposition. Here, we aimed (1) to elucidate whether P. brassicae eggs induce parasitoid-arresting leaf surface changes in another Brassicacean plant, i.e., Arabidopsis thaliana, and, if so, (2) to chemically characterize the egg-induced leaf surface changes. Egg deposition by P. brassicae on A. thaliana leaves had similar effects to egg deposition on Brussels sprouts with respect to the following: (a) Egg deposition induced leaf surface changes that arrested T. brassicae egg parasitoids. (b) Application of ARG secretion of mated female butterflies or of BC to leaves had the same inductive effects as egg deposition. Based on these results, we conducted GC-MS analysis of leaf surface compounds from egg- or ARG-induced A. thaliana leaves. We found significant quantitative differences in epicuticular waxes compared to control leaves. A discriminant analysis separated surface extracts of egg-laden, ARG-treated, untreated control and Ringer solution-treated control leaves according to their quantitative chemical composition. Quantities of the fatty acid tetratriacontanoic acid (C34) were significantly higher in extracts of leaf surfaces arresting the parasitoids (egg-laden or ARG-treated) than in respective controls. In contrast, the level of tetracosanoic acid (C24) was lower in extracts of egg-laden leaves compared to controls. Our study shows that insect egg deposition on a plant can significantly affect the quantitative leaf epicuticular wax composition. The ecological relevance of this finding is discussed with respect to its impact on the behavior of egg parasitoids.
Plant Volatiles Induced by Herbivore Egg Deposition Affect Insects of Different Trophic Levels
Fatouros, N.E. ; Lucas-Barbosa, D. ; Weldegergis, B.T. ; Pashalidou, F.G. ; Loon, J.J.A. van; Dicke, M. ; Harvey, J.A. ; Gols, R. ; Huigens, M.E. - \ 2012
PLoS ONE 7 (2012)8. - ISSN 1932-6203
furcifera horvath homoptera - elm leaf beetle - whitebacked planthopper - cotesia-glomerata - herbaceous plants - pieris-brassicae - host location - rice plants - oviposition - defense
Plants release volatiles induced by herbivore feeding that may affect the diversity and composition of plant-associated arthropod communities. However, the specificity and role of plant volatiles induced during the early phase of attack, i.e. egg deposition by herbivorous insects, and their consequences on insects of different trophic levels remain poorly explored. In olfactometer and wind tunnel set-ups, we investigated behavioural responses of a specialist cabbage butterfly (Pieris brassicae) and two of its parasitic wasps (Trichogramma brassicae and Cotesia glomerata) to volatiles of a wild crucifer (Brassica nigra) induced by oviposition of the specialist butterfly and an additional generalist moth (Mamestra brassicae). Gravid butterflies were repelled by volatiles from plants induced by cabbage white butterfly eggs, probably as a means of avoiding competition, whereas both parasitic wasp species were attracted. In contrast, volatiles from plants induced by eggs of the generalist moth did neither repel nor attract any of the tested community members. Analysis of the plant’s volatile metabolomic profile by gas chromatography-mass spectrometry and the structure of the plant-egg interface by scanning electron microscopy confirmed that the plant responds differently to egg deposition by the two lepidopteran species. Our findings imply that prior to actual feeding damage, egg deposition can induce specific plant responses that significantly influence various members of higher trophic levels.
Characterization of the internal resistance of a plant microbial fuel cell
Timmers, R.A. ; Strik, D.P.B.T.B. ; Hamelers, H.V.M. ; Buisman, C.J.N. - \ 2012
Electrochimica Acta 72 (2012). - ISSN 0013-4686 - p. 165 - 171.
exchange membranes - rice plants - electricity - rhizodeposits - generation - transport - bacteria
The objective of this research was to clarify the internal resistance of the PMFC. To characterize internal resistances of the PMFC current interrupt and polarization were used, and partial resistances were calculated. The internal resistance consisted mainly of anode resistance and membrane resistance which both decreased during current interrupt. The anode resistance was the result of mass transfer resistance in the electrochemically active biofilm. The membrane resistance was the result of accumulation of cations in the cathode. The polarization showed a distinct hysteresis which was explained by the increase of the internal resistance during polarization. The increase of this resistance makes it difficult to interpret the maximum power output of the PMFC.
Microbial community structure elucidates performance of Glyceria maxima plant microbial fuel cell
Timmers, R.A. ; Rothballer, M. ; Strik, D.P.B.T.B. ; Engel, M. ; Schulz, M. ; Hartmann, A. ; Hamelers, H.V.M. ; Buisman, C.J.N. - \ 2012
Applied Microbiology and Biotechnology 94 (2012)2. - ISSN 0175-7598 - p. 537 - 548.
targeted oligonucleotide probes - iron-reducing bacteria - in-situ hybridization - electricity-generation - fe(iii)-reducing bacterium - shewanella-putrefaciens - activated-sludge - soil bacteria - rice plants - human feces
The plant microbial fuel cell (PMFC) is a technology in which living plant roots provide electron donor, via rhizodeposition, to a mixed microbial community to generate electricity in a microbial fuel cell. Analysis and localisation of the microbial community is necessary for gaining insight into the competition for electron donor in a PMFC. This paper characterises the anode-rhizosphere bacterial community of a Glyceria maxima (reed mannagrass) PMFC. Electrochemically active bacteria (EAB) were located on the root surfaces, but they were more abundant colonising the graphite granular electrode. Anaerobic cellulolytic bacteria dominated the area where most of the EAB were found, indicating that the current was probably generated via the hydrolysis of cellulose. Due to the presence of oxygen and nitrate, short-chain fatty acid-utilising denitrifiers were the major competitors for the electron donor. Acetate-utilising methanogens played a minor role in the competition for electron donor, probably due to the availability of graphite granules as electron acceptors.
Rhizosphere anode model explains high oxygen levels during operation of a Glyceria maxima PMFC
Timmers, R.A. ; Strik, D.P.B.T.B. ; Arampatzoglou, C. ; Buisman, C.J.N. ; Hamelers, H.V.M. - \ 2012
Bioresource Technology 108 (2012). - ISSN 0960-8524 - p. 60 - 67.
microbial fuel-cells - triticum-aestivum l - rice plants - electricity production - root exudation - organic-acids - carbon - solubilization - rhizodeposits - turnover
In this paper, the effect of root oxygen loss on energy recovery of the plant microbial fuel cell (PMFC) is described. In this manner, advanced understanding of competing processes within the rhizosphere-anode interface was provided. A microscopic model was developed on the basis of exudation, oxygen loss, biological oxidation, and biological current generation. The model was successfully validated by comparison to oxygen concentration profiles, volatile fatty acid profiles, and chemical oxygen demand profiles measured in the anode compartment. The model predicted oxic zones around roots in the anode of the plant microbial fuel cell. Results show no direct link between current generation and photosynthesis. This was consistent with the model which predicted that current was generated via hydrolysis of root-derived organic compounds. This result means that to optimize energy recovery of a PMFC, the plant selection should focus on high root biomass production combined with low oxygen loss.
Microbial solar cells: applying photosynthetic and electrochemically active organisms
Strik, D.P.B.T.B. ; Timmers, R.A. ; Helder, M. ; Steinbusch, K.J.J. ; Hamelers, H.V.M. ; Buisman, C.J.N. - \ 2011
Trends in Biotechnology 29 (2011)1. - ISSN 0167-7799 - p. 41 - 49.
fuel-cells - electricity production - bioelectrochemical systems - energy performance - green electricity - biogas production - oxygen reduction - ion-transport - waste-water - rice plants
Microbial solar cells (MSCs) are recently developed technologies that utilize solar energy to produce electricity or chemicals. MSCs use photoautotrophic microorganisms or higher plants to harvest solar energy, and use electrochemically active microorganisms in the bioelectrochemical system to generate electrical current. Here, we review the principles and performance of various MSCs in an effort to identify the most promising systems, as well as the bottlenecks and potential solutions, for “real-life” MSC applications. We present an outlook on future applications based on the intrinsic advantages of MSCs, specifically highlighting how these living energy systems can facilitate the development of an electricity-producing green roof.
Transgene organisation in potato after particle bombardment-mediated (co-) transformation using plasmids and gene cassettes
Romano, A. ; Raemakers, C.J.J.M. ; Bernardi, J. ; Visser, R.G.F. ; Mooibroek, A. - \ 2003
Transgenic Research 12 (2003). - ISSN 0962-8819 - p. 461 - 474.
agrobacterium-tumefaciens - t-dna - amylose-free - integration patterns - rice plants - transformation - arabidopsis - starch - expression - cotransformation
Protocols for efficient co-transformation of potato internodes with genes contained in separate plasmids or gene cassettes (i.e., linear PCR fragments comprising a promoter-gene-terminator) using particle bombardment were established. Twenty-eight out of 62 (45%) and 11 out of 65 (17%) plants transformed with a plasmid containing the selectable marker contained one and two additional non-selected genes, respectively. When gene cassettes were used in transformation, six out of eight plants were co-transformed. Expression analysis showed that 75-80% of the plants transformed with two transgenes expressed both of them, irrespective of the use of plasmids or gene cassettes. Thirty-eight plants containing the gusA reporter-gene and the nptII selectable-marker have been characterised with respect to the molecular organisation of the donor DNAs. Seventeen out of 49 (35%) gusA sites of integration contained one copy of the gene. Only 11 gusA sites (22%) were linked to the site of integration of the selectable marker. When one site of integration contained several copies of the transgene, a predominance of 3'-3' inverted re-arrangement repeats was observed.