Isolation and genetical analyses on phytase producing bacteria in the rumen

通过一系列实验对肠道细菌的挥发性硫产生能力进行了评价。由粪便产生的甲硫醇和硫化氢是集约化畜牧业领域的环境问题。我们已经从一系列实验室菌株中鉴定出四种梭菌菌株和五种其他甲烷乙烯利生产菌，这些菌株可能存在于牲畜的大肠中。我们还从猪粪便中分离出产气荚膜梭菌，它是一种有效的甲硫醇生产菌。与从L-蛋氨酸产生甲烷硫醇不同，许多实验室菌株从L-胱氨酸产生硫化氢。我们已经鉴定睾丸酮丛毛单胞菌JCM 5832为有效的硫化氢降解剂。我们从养猪场的土壤中分离到一株分解硫化氢的芽孢杆菌，其分解硫化氢的效率与睾丸酮丛毛单胞菌相当。通过气味指数分析评价了这些细菌对猪粪便的除臭能力，睾丸酮梭菌使猪粪便的气味指数从26降低到21，而我们分离的芽孢杆菌使其从26降低到19.5。16 S rDNA序列分析表明，该菌株与苏云金芽孢杆菌（B. thuringiensis）相似。

A series of experiments were conducted to evaluate volatile sulfur producing ability of a range of intestinal bacteria. Methanethiol and hydrogen sulfide generated from feces present an environmental issue in the intensive field of animal agriculture. We have identified four strains of clostridia and five others a methanethiol producers from a range of laboratory strains, which may be present in the large intestines of livestock. We have also isolated on Clostridium perfringens from pig feces as a potent producer of methanethiol. Unlike methanethiol from L-methionine, many laboratory strains produced hydrogen sulfide from L-cystine.Next to these experiments, we eveluate the ability of volatile sulfur decomposition of a range of a aerobic heterotrophs. We have identified Comamonas testosteroni JCM 5832 as a potent hydrogen sulfide degrader. We have isolatead a Baciilus from soil in a pig farm that decomposes hydrogen sulfide as efficient a Comamonas testosteroni. The abilities of these bacteria to decrease odor of pig feces were evaluated by odor lank analyses.C.testosteroni decreased odor index from 26 to 21, while our Bacillus isolate decrease it from 26 to 19.5. 16S rDNA sequence of this Bacillus indicated that it resemble to B.thuringiensis.