嗜热菌株AT07-1的分离鉴定及其在污泥溶解预处理厌氧发酵产氢中的应用

Isolation and characterization of Bacillus thermophilic bacteria AT07-1 and its application in sludge solubilization and bio-hydrogen production by anaerobic fermentation

从湖南大学花园土壤中采集样品,用稀释涂布法分离和纯化适于污泥溶解的典型嗜热菌菌株,从中选出一株高效菌进行形态观察,并对其进行生理生化鉴定.结果表明,该菌株的革兰氏染色为阳性,呈细杆状,产芽孢,为好氧或兼性需氧细菌,最适生长温度为65℃,最适生长pH值为6.8-7.5.通过16SrDNA碱基测序和对比证实,该菌株是目前尚未报道过的一株嗜热菌,GenBank中注册命名为Bacillus thermophilicbacteriaAT07-1（注册号：FJ231108）.同时,将其纯种菌用于嗜热酶溶解（solubilization by thermophilic enzyme,S-TE）污泥稳定化处理,接种该嗜热菌可促进污泥中悬浮固体的溶解,2.5d时接种试验挥发性悬浮固体（volatile suspended solid,VSS）溶解率达到59.41%,比不接种试验同期提高了25.58%,达到了EPA规定的污泥稳定化要求.进一步对经AT07-1预处理的污泥厌氧产氢效果进行研究,试验结果显示,接种处理后污泥发酵产氢效果良好,高出未接种处理（65℃热处理）污泥26.4%,发酵气体中只含有H2和CO2.

A novel strain of thermophilic bacteria with high efficiency for sludge dissolution was isolated from garden soil by the method of dilution spread.The strain＇s colony morphology,physiological and biochemical characteristics were observed.Results showed that the strain was a small,Gram-positive,rod-shaped,spore-forming,aerobic or facultative aerobic bacterium.The strain grew optimally at 65℃ and pH 6.8～7.5.The 16S rDNA analysis showed that the strain has not been previously reported and therefore it was labeled Bacillus thermophilic bacteria AT07-1（registration number：FJ231108）.The pure culture of the strain was then used in sludge solubilization tests（S-TE tests）and an enhanced solubilization process was obtained.The volatile suspended solid（VSS）solubilization rate reached 59.41% at 2.5 d after the inoculation,25.58% higher than the process without it,which meets the standard of sludge stability suggested by the U.S.Environmental Protection Agency.Preliminary investigations on hydrogen production from anaerobic fermentation of sludge showed that bio-hydrogen production after pretreatment with Bacillus thermophilic bacteria AT07-1was 26.4% higher than without it,and the biogas was only composed of hydrogen and carbon dioxide.