已確定細(xì)菌為高效發(fā)電器,,此細(xì)菌通常是在地球30公里以上發(fā)現(xiàn)的細(xì)菌。
同溫層芽孢桿菌(Bacillus stratosphericus )是一種常見(jiàn)微生物,,它存在于與衛(wèi)星一起繞地球運(yùn)行的高濃度平流層中,,是一種超級(jí)生物膜的一個(gè)關(guān)鍵組分,這種生物膜已被一隊(duì)紐卡斯?fàn)柎髮W(xué)科學(xué)家工程構(gòu)建,。
對(duì)來(lái)自戴河口,、國(guó)達(dá)拉謨、英國(guó)的75種不同細(xì)菌進(jìn)行分離,,研究小組用一種微生物燃料電池(MFC)測(cè)試了每一處微生物的發(fā)電力,。
通過(guò)選擇最佳物種細(xì)菌,一種"挑選和組合"微生物創(chuàng)造了一個(gè)人工生物膜,,成倍增加了MFC的電輸出,,從105瓦每立方米200瓦每立方米。
盡管還是相當(dāng)?shù)?,這對(duì)運(yùn)行一個(gè)電燈來(lái)說(shuō)是足夠的電力,,并可以提供給世界無(wú)電地區(qū)一個(gè)非常必要的電源。
在"超級(jí)"蟲(chóng)中,,同溫層芽孢桿菌是一種大氣中常見(jiàn)由于大氣循環(huán)過(guò)程被帶到地球的微生物,,并被研究小組從戴河河床中分離出來(lái),。
此研究結(jié)果發(fā)表在美國(guó)化學(xué)協(xié)會(huì)期刊Journal of Environmental Science and Technology上,顯示了技術(shù)的潛力,。
已經(jīng)做的就是有意地模仿微生物組合來(lái)工程化一種能更有效發(fā)電的生物膜,。這是首次以這樣的方式來(lái)研究與選擇單個(gè)微生物。同溫層芽孢桿菌的發(fā)現(xiàn)很令人吃驚,,它所表明的是這種技術(shù)對(duì)將來(lái)的潛力,,在具發(fā)電潛力的微生物之外還有數(shù)十億種微生物。
使用微生發(fā)電不是一種新觀點(diǎn),,它已被用于廢水與污水廠的治理中,。
微生物燃料電池,它以一種與電池相似的方式工作,,利用細(xì)菌通過(guò)一個(gè)生物催化氧化作用過(guò)程將有機(jī)化合物直接轉(zhuǎn)換為電,。
一種生物膜或粘液涂在MFC的炭精電極上,當(dāng)細(xì)菌進(jìn)食時(shí)產(chǎn)生電子,,這些電子傳入電極并產(chǎn)生電流,。
直到現(xiàn)在,生物膜一直在不受檢查地生長(zhǎng),,但是這項(xiàng)新研究首次表明,,通過(guò)操控生物膜,你能明顯地增加燃料電池的電輸出,。
與同溫層芽孢桿菌一樣,,混合物中其他電流生產(chǎn)蟲(chóng)是高地芽孢桿菌(Bacillus altitudinis),它是另一種來(lái)自高空大氣的蟲(chóng),,也是硬壁菌門(mén)(Bacteroidetes)的一個(gè)新成員,。
在燃料電池技術(shù)上,紐卡斯?fàn)柎髮W(xué)是公認(rèn)的國(guó)際領(lǐng)先水平,。紐卡斯?fàn)柎髮W(xué)化學(xué)工程與先進(jìn)材料學(xué)院Keith Scott教授領(lǐng)導(dǎo)的研究小組在2年前新鋰/空氣動(dòng)力電池的開(kāi)發(fā)中起關(guān)鍵作用,。
最新的燃料電池研究能將MFC發(fā)展帶到一個(gè)新水平。(生物谷bioon.com)
doi:10.1021/es2020007
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Enhanced electricity production by use of reconstituted artificial consortia of estuarine bacteria grown as biofilms
Jinwei Zhang, Enren Zhang, Keith Scott and Grant Burgess
ABSTRACT Microbial fuel cells (MFCs) can convert organic compounds directly into electricity by catalytic oxidation, and although MFCs have attracted considerable interest, there is little information on the electricity-generating potential of artificial bacterial biofilms. We have used acetate-fed MFCs inoculated with sediment, with two-chamber bottles and carbon cloth electrodes to deliver a maximum power output of 175 mW·m-2 and a stable power output of 105 mW·m-2. Power production was by direct transfer of electrons to the anode from bacterial consortia growing on the anode, as confirmed by cyclic voltammetry (CV) and scanning electron microscopy (SEM). Twenty different species (74 strains) of bacteria were isolated from the consortium under anaerobic conditions and cultured in the laboratory, of which 34% were found to be exoelectrogens in single-species studies. Exoelectrogenesis by members of the genera Vibrio, Enterobacter, and Citrobacter and by Bacillus stratosphericuswas confirmed, by use of culture-based methods, for the first time. An MFC with a natural bacterial consortium showed higher power densities than those obtained with single strains. In addition, the maximum power output could be further increased to 200 mW·m-2 when an artificial consortium consisting of the best 25 exoelectrogenic isolates was used, demonstrating the potential for increased performance and underlying the importance of artificial biofilms for increasing power output.