一株耐盐产电菌Shewanella algae E-1的分离及其产电特性分析

【背景】产电微生物的种类和电化学活性机制对微生物燃料电池的产电性能有着重要的影响。【目的】从海水中分离获得一株耐盐产电微生物,研究其产电特性并鉴定种属信息。【方法】以取自南海的海水为接种液启动并运行阳极液中含有不同盐浓度的微生物燃料电池,从富集的阳极生物膜上分离得到一株纯培养的微生物菌株,命名为E-1。通过接种于阳极液中添加不同盐浓度的微生物燃料电池中对其产电特性进行分析,并利用形态学观察、Biolog分析和16SrRNA基因序列比对相结合的方法进行种属鉴定。【结果】菌株E-1在无外源添加和外源添加6.6%NaCl条件下产生的功率密度分别为51.69 m W/m2和26.56 m W/m2,这与其良好的耐盐能力相关。菌株E-1被鉴定为海藻希瓦氏菌(Shewanella algae),表现出多样的底物利用能力,生长的温度范围为25-40°C,pH范围为5.0-10.0。【结论】这是首次对Shewanella algae种内微生物产电性能及其在微生物燃料电池中应用的报道,丰富了产电微生物的多样性,菌株E-1能够在较高盐浓度条件下表现出良好的产电性能,为微生物燃料电池在海水资源化处理方面的应用提供新的实验材料。     

微生物燃料电池内阻及其影响因素分析

微生物燃料电池(MFC)是一种通过微生物的催化作用将有机物中的化学能直接转化为电能的生物反应装置,研究表明内阻是限制微生物燃料电池产能的重要因素。本文对目前国内外有关微生物燃料电池内阻的研究成果进行了总结,系统介绍了微生物燃料电池内阻定义、构成和常用的微生物燃料电池内阻测定方法,重点分析了反应器、产电底物、产电微生物和操作条件等对微生物燃料电池内阻的影响,并结合已有的研究结果提出了降低内阻、提高微生物燃料电池产电性能的可行性方法。     

微生物燃料电池中阳极产电微生物的研究进展

微生物燃料电池（MFC）是利用阳极产电微生物为催化剂降解有机废物直接将化学能转化为电能的装置。在MFC系统中,产电微生物是影响产电性能的核心要素之一。介绍了MFC中产电微生物的最新研究现状,详细讨论了产电微生物的种类、产电机理和产电能力．为产电微生物的富集、驯化、改造和多种菌种优化组合提供思路。     

微生物燃料电池中假单胞菌F026的产电性能研究

基于微生物燃料电池的反应装置,从污水处理厂曝气池的污泥中通过富集,筛选和基于16S rRNA基因序列的系统发育分析等手段驯化出1株高效产电假单胞菌F026。以F026为阳极产电菌制作微生物燃料电池,考察了底物种类、温度和p H值等因素对微生物燃料电池产电性能的影响。结果表明,F026最适合在以可溶性淀粉为底物,p H为中性偏碱性,温度在30~35℃的环境下生长。在此条件下,微生物燃料电池的最高电压达到500 m V,体积功率密度达到2 W/m3。     

pH值对微生物燃料电池处理生物废弃物的影响

以生物废弃物为底物,采用双室微生物燃料电池对生物废弃物进行处理,研究阳极液初始pH值对生物废弃物CODcr、TOC去除率的影响,以及对微生物燃料电池产电性能影响。实验结果表明,当阳极液pH值为6时,CODcr去除率达72.1%,TOC的去除率达44.5%,其输出电压最大为1.27 V,平均电压797 mV,最大功率密度达到136.6 mW/m2。     

沉积型海底微生物燃料电池构建及其影响因素研究

海底微生物燃料电池具有底物丰富、可长期运行、维护成本低和环境友好等特点,具有很好的研究价值和广阔的发展前景。但由于其低的功率密度输出和长期运行的不稳定性,使海底微生物燃料电池尚未得到广泛地实际应用。选取海底沉积泥用于实验室构建的海底微生物燃料电池装置中,比较了在不同阳极材料、阴阳极面积比、阳极修饰、阳极泥下深度条件下海底微生物燃料电池的功率密度输出及其电化学性能,得出最佳的海底微生物燃料电池阳极材料为碳毡;阴极及电极最佳面积比为1∶1;最佳阳极修饰为氨水浸渍;最佳阳极泥下深度为2 cm。     

产电菌群及电子受体对微生物燃料电池性能的影响

采用2种类型的微生物燃料电池--常规微生物燃料电池(S-MFCs,以生活污水作为产电菌群接种源、以硝酸盐作为电子受体）和改进后的微生物燃料电池（A-MFCs,以厌氧发酵液作为产电菌群接种源、以铁氰化物作为电子受体）,分析了产电菌群和电子受体的改进对微生物燃料电池产电性能的影响.结果表明：产电菌群和电子受体对MFCs驯化周期和运行周期具有显著影响,使驯化周期由S-MFCs的500 h缩短到A-MFCs的430 h,运行周期由S-MFCs的100 h增加到A-MFCs的350 h;改进后的微生物燃料电池使COD去除率提升了25%,使电压输出提高了约300%.选择合适的产电菌菌种和电子受体标准电极电势是微生物燃料电池性能提升的基础.     

微生物燃料电池在固体废物堆肥中的应用进展

微生物燃料电池(Microbial fuel cell,MFC)是一种近几年快速发展的废物处理与能源化技术,可以与污水处理、污染物降解、脱盐等环境技术结合。微生物燃料电池与堆肥技术结合可以在处理日益增长的固体废弃物的同时回收能量,具有很好的发展前景。文中分析了堆肥微生物燃料电池系统的微生物特征,探讨了堆肥过程中影响微生物燃料电池产电性能的因素,包括电极,隔膜,供氧和构型。最后归纳说明了堆肥微生物电池作为一种新的废弃物处理技术的特点:较高的微生物量并可产生较高的电流密度;对不同环境的适应性强;可以自身调节温度,能源利用效率高;质子从阳极向阴极的移动会受到不同堆肥原料的影响。     

微生物燃料电池阳极产电微生物和阴极受体特性及研究进展

介绍微生物燃料电池的基本工作原理。根据电子传递方式阳极产电微生物分为无需中间体微生物和需中间体微生物。对阴极进行不同反应所涉及的最终电子受体进行了概述,并展望了微生物燃料电池的应用前景。     

微生物燃料电池中产电微生物的研究进展

微生物燃料电池(Microbial fuel cell,MFC)作为一种新型的环境治理和能源技术,目前已得到研究者们的广泛关注。微生物燃料电池是一种利用微生物将有机物中的化学能转化成电能的装置,产电微生物作为生物催化剂,对微生物燃料电池的发展至关重要。不同种类的产电微生物,其电子转移机制与能力有所差异,直接影响MFC的产电性能,从而决定MFC在工程实践中的性能与应用。任何含有大量微生物的废水、污泥、沉积物都可以作为产电微生物的筛选来源,尝试从不同环境条件下分离筛选高效产电微生物有望促进MFC的进一步完善,从而加速其在环境中的应用。通过对微生物燃料电池的发展、产电微生物种类及其电子传递机制等进行总结分析,综述了MFC中产电微生物的最新研究进展,包括产电微生物的筛选方法、种类以及技术研究等,最后展望了今后在产电微生物方面的主要研究方向及MFC的发展前景,以期为产电微生物的的筛选和应用奠定相应的理论基础及提供思路。     

The significance of the initiation process parameters and reactor design for maximizing the efficiency of microbial fuel cells

Microbial fuel cells (MFCs) can be used for electricity generation via bioconversion of wastewater and organic waste substrates. MFCs also hold potential for production of certain chemicals, such as H₂ and H₂O₂. The studies of electricity generation in MFCs have mainly focused on the microbial community formation, substrate effect on the anode reaction, and the cathode’s catalytic properties. To improve the performance of MFCs, the initiation process requires more investigation because of its significant effect on the anodic biofilm formation. This review explores the factors which affect the initiation process, including inoculum, substrate, and reactor configuration. The key messages are that optimal performance of MFCs for electricity production requires (1) understanding of the electrogenic bacterial biofilm formation, (2) proper substrates at the initiation stage, (3) focus on operational conditions affecting initial biofilm formation, and (4) attention to the reactor configuration.     

Impact of a static magnetic field on the electricity production of Shewanella-inoculated microbial fuel cells

The electricity production of Shewanella-inoculated microbial fuel cells (MFCs) under magnetic field (MF) exposure was investigated in different reactor systems. The persistency of the MF effect and the influences of MF intensity and direction on MFC performance were also studied. Application of a 100-mT static MF to the MFCs improved electricity production considerably, with an increase in the maximum voltage by 20-27% in both single- and two-chamber MFCs, while a more conspicuous improvement in the electricity generation was observed in a three-electrode cell. The MF effects were found to be immediate and reversible, and adverse effects seemed to occur when the MF was suddenly removed. The medium components analysis demonstrated that the application of MF led to an enhanced bioelectrochemical activity of Shewanella, and no significant promotion in mediator secretion was found. The improvement in the electricity production of MFCs under MF was mainly attributed to the enhanced bioelectrochemical activity, possibly through the oxidative stress mechanism. An accelerated cell growth under MF might also contribute to the enhanced substrate degradation and power generation.     

Improving energy accumulation of microbial fuel cells by metabolism regulation using Rhodoferax ferrireducens as biocatalyst

AIMS: To study the physiology and metabolism of microbial cells in the performance of microbial fuel cells (MFCs). METHODS AND RESULTS: A dual-chamber MFCs was constructed, and Rhodoferax ferrireducens was used as biocatalyst. To examine the physiology of microbial cells in the performance of MFCs, the anode media containing planktonic cells was replaced with fresh media in which KH(2)PO(4) and/or NH(4)Cl were excluded. The replacing of anode media containing planktonic cells with fresh media excluded of KH(2)PO(4) and NH(4)Cl made the coulombic yield remarkably increased by a factor of 68% (from 29.1 to 46.8C). The results showed that the electricity could be generated with cells in biofilms as biocatalyst, and coulombic yield was improved by limiting cell growth via removal of ingredients in anode media. By supplementation of glucose to the anode media when current declined to baseline, MFCs achieved about same platform current values immediately. MFCs could continue to produce electricity for about 30 h even after glucose was below detection. CONCLUSIONS: Biofilms and metabolism of glucose play important roles in the performance of MFCs. Coulombic yield of MFCs could be improved by regulating the media ingredients using the stable biofilms-electrode system. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first attempt to study the effect of ingredient compositions of anode media on the performance of MFCs. The observed results that MFCs continued to produce electricity after glucose was below detection was helpful to better understand the mechanism of microbial electricity production.     

Effect of enrichment procedures on performance and microbial diversity of microbial fuel cell for Congo red decolorization and electricity generation

The purpose of this study was to determine the effect of enrichment procedure on the performance and microbial diversity of an air-cathode microbial fuel cell (MFC) which was explored for simultaneous azo dye decolorization and electricity generation. Two different enrichment procedures in which glucose and Congo red were added into the MFCs sequentially (EP1) or simultaneously (EP2) were tested by operating parallel MFCs independently for more than 6 months. The power density, electrode potential, Congo red decolorization, biofilm morphology, and bacterial diversity of the MFCs under the two enrichment procedures were compared and investigated. The results showed that the enrichment procedures have a negligible effect on the dye decolorization, but significantly affected the electricity generation. More than 90% decolorization at dye concentration of 300 mg/L was achieved within 170 h for the two tested enrichment procedures. However, the MFC with EP2 achieved a maximum power density of 192 mW/m², which was 75% higher than that of the MFC with EP1 (110 mW/m²). The depressed surfaces of the bacteria in the MFC with EP1 indicated the allergic response caused by the subsequent addition of Congo red. 16S rRNA sequencing analysis demonstrated a phylogenetic diversity in the communities of the anode biofilm and showed clear differences between the anode-attached populations in the MFCs with a different enrichment procedure. This study suggests that the enrichment procedure is important for the MFC explored for simultaneous dye decolorization and electricity generation.     

光合细菌在微生物燃料电池中的应用研究进展

微生物燃料电池(Microbial fuel cells,MFCs)降解污染物的同时产生电能,受到广泛关注。光合细菌在MFCs领域的应用实现了污水处理、CO2捕捉、光电转换等多重功能,并显示出了良好的产电特性。本文根据光合细菌在MFCs中所起作用的不同对其产电机理进行评述,并在此基础上分析了光照对光合细菌型MFCs产电性能的影响;针对当前研究的不足与面临的问题,提出了今后光合细菌在MFCs领域的应用前景与发展方向。     

Increased power generation from primary sludge in microbial fuel cells coupled with prefermentation

Raw primary sludge and the prefermentation liquor (PL) of primary sludge were used to generate electricity in single-chambered air-cathode microbial fuel cells (MFCs). The MFCs treating the primary sludge produced 0.53 V and 370 mW/m² for the maximum potential and power density, respectively. In the primary sludge-fed MFCs, only 5 % of the total energy production was produced from direct electricity generation, whereas 95 % of that resulted from the conversion of methane to electricity. MFCs treating the PL generated the maximum potential of 0.58 V and maximum power density of 885 mW/m², respectively. In the energy production analysis, direct electricity production (1,921 Wh/kg TCOD_rem) in the MFCs treating the PL was much higher than that of the primary sludge-fed MFC (138 Wh/kg TCOD_rem). Volatile suspended solids during 10 days were reduced to 18.3 and 38 % in the primary sludge-fed MFCs and prefermentation reactor, respectively. These findings suggest that a two-stage process including prefermentation and MFCs is of great benefit on sludge reduction and higher electricity generation from primary sludge.     

Use of Pseudomonas species producing phenazine-based metabolites in the anodes of microbial fuel cells to improve electricity generation

The rate of anodic electron transfer is one of the factors limiting the performance of microbial fuel cells (MFCs). It is known that phenazine-based metabolites produced by Pseudomonas species can function as electron shuttles for Pseudomonas themselves and also, in a syntrophic association, for Gram-positive bacteria. In this study, we have investigated whether phenazine-based metabolites and their producers could be used to improve the electricity generation of a MFC operated with a mixed culture. Both anodic supernatants obtained from MFCs operated with a Pseudomonas strain (P-PCA) producing phenazine-1-carboxylic acid (PCA) and those from MFCs operated with a strain (P-PCN) producing phenazine-1-carboxamide (PCN) exerted similarly positive effects on the electricity generation of a mixed culture. Replacing supernatants of MFCs operated with a mixed culture with supernatants of MFCs operated with P-PCN could double the currents generated. Purified PCA and purified PCN had similar effects. If the supernatant of an engineered strain overproducing PCN was used, the effect could be maintained over longer time courses, resulting in a 1.5-fold increase in the production of charge. Bioaugmentation of the mixed culture MFCs using slow release tubes containing P-PCN not only doubled the currents but also maintained the effect over longer periods. The results demonstrated the electron-shuttling effect of phenazine-based compounds produced by Pseudomonas species and their capacity to improve the performance of MFCs operated with mixed cultures. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Dynamic changes in the microbial community composition in microbial fuel cells fed with sucrose

The performance and dynamics of the bacterial communities in the biofilm and suspended culture in the anode chamber of sucrose-fed microbial fuel cells (MFCs) were studied by using denaturing gradient gel electrophoresis (DGGE) of PCR-amplified partial 16S rRNA genes followed by species identification by sequencing. The power density of MFCs was correlated to the relative proportions of species obtained from DGGE analysis in order to detect bacterial species or taxonomic classes with important functional role in electricity production. Although replicate MFCs showed similarity in performance, cluster analysis of DGGE profiles revealed differences in the evolution of bacterial communities between replicate MFCs. No correlation was found between the proportion trends of specific species and the enhancement of power output. However, in all MFCs, putative exoelectrogenic denitrifiers and sulphate-reducers accounted for approximately 24% of the bacterial biofilm community at the end of the study. Pareto–Lorenz evenness distribution curves extracted from the DGGE patterns obtained from time course samples indicated community structures where shifts between functionally similar species occur, as observed within the predominant fermentative bacteria. These results suggest the presence of functional redundancy within the anodic communities, a probable indication that stable MFC performance can be maintained in changing environmental conditions. The capability of bacteria to adapt to electricity generation might be present among a wide range of bacteria.     

Electricity generation and microbial community response to substrate changes in microbial fuel cell

The effect of substrate changes on the performance and microbial community of two-chamber microbial fuel cells (MFCs) was investigated in this study. The MFCs enriched with a single substrate (e.g., acetate, glucose, or butyrate) had different acclimatization capability to substrate changes. The MFC enriched with glucose showed rapid and higher power generation, when glucose was switched with acetate or butyrate. However, the MFC enriched with acetate needed a longer adaptation time for utilizing glucose. Microbial community was also changed when the substrate was changed. Clostridium and Bacilli of phylum Firmicutes were detected in acetate-enriched MFCs after switching to glucose. By contrast, Firmicutes completely disappeared and Geobacter-like species were specifically enriched in glucose-enriched MFCs after feeding acetate to the reactor. This study further suggests that the type of substrate fed to MFC is a very important parameter for reactor performance and microbial community, and significantly affects power generation in MFCs.     

Micro-sized microbial fuel cell: A mini-review

This review presents the development of micro-sized microbial fuel cells (including mL-scale and μL-scale setups), with summarization of their advantageous characteristics, fabrication methods, performances, potential applications and possible future directions. The performance of microbial fuel cells (MFCs) is affected by issues such as mass transport, reaction kinetics and ohmic resistance. These factors are manipulated in micro-sized MFCs using specially allocated electrodes constructed with specified materials having physically or chemically modified surfaces. Both two-chamber and air-breathing cathodes are promising configurations for mL-scale MFCs. However, most of the existing μL-scale MFCs generate significantly lower volumetric power density compared with their mL-counterparts because of the high internal resistance. Although μL-scale MFCs have not yet to provide sufficient power for operating conventional equipment, they show great potential in rapid screening of electrochemically microbes and electrode performance. Additional possible applications and future directions are also provided for the development of micro-sized MFCs.