Institute of Marine Biology, National Taiwan Ocean University, Keelung, Taiwan.
Microbes Environ. 2011;26(4):317-24. doi: 10.1264/jsme2.me10202. Epub 2011 Jun 18.
A new extremely thermophilic, anaerobic, gram-negative bacterium, strain NTOU1, was enriched and isolated from acidic marine hydrothermal fluids off Gueishandao island in Taiwan with 0.5% starch and 0.5% maltose as carbon sources. This strain was capable of growth utilizing various sugars found in lignocellulosic biomass as well as xylan and cellulose, and produced ethanol, lactate, acetate, and CO(2) as fermentation products. The results of a 16S rRNA gene sequence analysis (1,520 bp) revealed NTOU1 to belong to the genus Thermoanaerobacterium. When tested for the ability to grow and produce ethanol from xylose or rice straw hemicellulosic hydrolysate at 70°C, the strain showed the highest levels of ethanol production (1.65 mol ethanol mol xylose(-1)) in a medium containing 0.5% xylose plus 0.5% yeast extract. Maximum ethanol production from the rice straw hemicellulose was 0.509 g g(-1), equivalent to 98.8% theoretical conversion efficiency. Low concentrations of inhibitors (derived from dilute acid hydrolysis) in the rice straw hemicellulose hydrolysate did not affect the ethanol yield. Thus, Thermoanaerobacterium strain NTOU1 has the potential to be used for ethanol production from hemicellulose.
从台湾龟山岛附近的酸性海洋热液中，以 0.5%淀粉和 0.5%麦芽糖为碳源，富集并分离出一株新型的嗜热、厌氧、革兰氏阴性细菌，命名为 NTOU1 株。该菌能够利用木质纤维素生物质中的各种糖、木聚糖和纤维素进行生长，并产生乙醇、乳酸、乙酸和 CO2 作为发酵产物。16S rRNA 基因序列分析（1520bp）结果表明，NTOU1 属于热厌氧菌属。当在 70°C 下用木糖或水稻秸秆半纤维素水解物测试其生长和生产乙醇的能力时，该菌株在含有 0.5%木糖和 0.5%酵母提取物的培养基中显示出最高的乙醇产量（1.65mol 乙醇/mol 木糖）。从水稻秸秆半纤维素中获得的最大乙醇产量为 0.509gg-1，相当于 98.8%的理论转化率。水稻秸秆半纤维素水解物中低浓度的抑制剂（来源于稀酸水解）不会影响乙醇产量。因此，Thermoanaerobacterium 菌株 NTOU1 有潜力用于从半纤维素生产乙醇。
