CAJ | 학술논문

利用农业废弃物合成气发酵生产燃料乙醇不仅可以缓解中国的能源危机，也是减轻环境污染、促进农业可持续发展和改善农村环境的重要举措。该文对实验室富集获得的4个菌系及国内外报道较多的4个菌株发酵生物质合成气生产燃料乙醇的潜力进行了研究。结果表明：菌株LP-fm4、Clostridium sp. P11和A-fm4发酵生物质合成气生产乙醇的净产量分别为179.23、152.92和115.08 mg/L；菌体比生长速率分别为1.46、1.66和1.18 d-1；乙醇比生成速率分别3.50、2.05和0.78 d-1，单位菌体生成乙醇的量分别为2252.90、1450.20和1132.37 mg/g，显著高于其他菌株（群）。多重比较分析与综合性状聚类分析结果表明前两者为利用合成气高效发酵乙醇的理想菌体，菌 A-fm4为具有潜力菌体。以期为未来农业废弃物合成气乙醇发酵提供了优良的菌种资源。
이용농업폐기물합성기발효생산연료을순불부가이완해중국적능원위궤，야시감경배경오염、촉진농업가지속발전화개선농촌배경적중요거조。해문대실험실부집획득적4개균계급국내외보도교다적4개균주발효생물질합성기생산연료을순적잠력진행료연구。결과표명：균주LP-fm4、Clostridium sp. P11화A-fm4발효생물질합성기생산을순적정산량분별위179.23、152.92화115.08 mg/L；균체비생장속솔분별위1.46、1.66화1.18 d-1；을순비생성속솔분별3.50、2.05화0.78 d-1，단위균체생성을순적량분별위2252.90、1450.20화1132.37 mg/g，현저고우기타균주（군）。다중비교분석여종합성상취류분석결과표명전량자위이용합성기고효발효을순적이상균체，균 A-fm4위구유잠력균체。이기위미래농업폐기물합성기을순발효제공료우량적균충자원。
Ethanol is one of the most important alternative biofuels, which provides a net energy gain, has environmental benefits and is economically competitive. Ethanol production from syngas anaerobic fermentation appears to be a potential and promising technology compared to the existing chemical conversion techniques. Currently, syngas fermentation is being developed as one option towards the production of bio-ethanol from biomass. Agricultural residue biomass such as corn stalks and wheat stalks, has been an important part of the biomass resource in the world. Much attention has been attracted on the conversation and utilization of these biomasses with high value. The gasification of the agricultural residue biomass is a mature and industrialized technology up to now. Gasification of agricultural lignocellulosic residue followed by syngas fermentation to produce bio-ethanol is being explored owing to the low cost and availability of agricultural residue feedstock. The process can not only change trash to treasure but also be of benefit to reduce environmental pollution, which will promote the sustainable development of agriculture and improve the rural environment. It has been found that some anaerobic bacteria can be used to convert syngas to ethanol and acetic acid, such as Clostridium ljungdahlii and C. autoethanogenum. But the excellent strains are still very limited and their productivity levels are not high. According to the fact that bio-ethanol production from syngas in anaerobic conditions still can not be industrialized, special emphasis has been given to obtain the efficient microorganism fermenting that transfers syngas to ethanol. In order to obtain strains for high efficient ethanol production by syngas generated from agricultural residue, ethanol fermentations taking syngas as the sole carbon source and energy source were carried out. Ethanol production potentials were compared among the mixed-cultures A-fm4, B-fm4, G-fm4 and LP-fm4 and the reported strains Clostridium carboxidivorans P7, Clostridium sp. P11, C. ljungdahlii and C. autoethanogenum DSM10061. Meanwhile, microbial mixed-cultures A-fm4, B-fm4, G-fm4 and LP-fm4 were isolated from animal faeces samples of alpaca, papion, lesser panda and gibbon respectively under strict anoxic condition in 200 mL bottle. Batch fermentations were done in 300 mL serum bottles each containing 60 mL fermentation medium. 10%(v/v) of inoculum was transferred to fresh media. The 240 mL syngas was injected into the 300 mL serum bottle by syringe. Experiments were conducted for 7 days. The results showed that all of the cultures/mixed-cultures can transform syngas into biofuel ethanol. The net ethanol production and specific cell growth rate were 179.23, 152.92, 115.08 mg/L and 1.46, 1.66, 1.18 d-1, respectively, for culture/mixed-cultures LP-fm4, Clostridium sp. P11 and A-fm4. Their specific ethanol production rate and ethanol production amount per cell were 3.50, 2.05, 0.78 d-1 and 2252.90, 1450.20, 1132.37 mg/g (dry cell weight, DCW), respectively. These parameters were significantly higher than those of other treatments. Duncan analysis and dendrogram of cluster analysis also agreed that mixed-culture/strain LP-fm4 and Clostridium sp. P11 were the ideal microorganisms for ethanol production by syngas generated from agricultural residue, and mixed-culture A-fm4 was a potential candidate. The research results will provide excellent microorganisms for fermentation of syngas generated from agricultural residue in the future.