游离棉酚脱除菌株的分离鉴定及体内定植效果研究

该研究从藜麦茎叶和番茄杆样品中筛选分离出高效游离棉酚脱除菌株，为棉籽粕生物脱毒提供优良菌株。测定筛选菌株的游离棉酚脱除能力及产蛋白酶能力，采用人工胃液、人工肠液耐受实验，抗生素敏感实验及表面特性实验研究筛选菌株在体内定植能力，并通过形态学观察、生理生化试验及16S rDNA序列分析对筛选菌株进行鉴定。结果表明，筛选出1株高效游离棉酚脱除芽孢杆菌，编号为S-77，其游离棉酚脱除率为81.30%，产蛋白酶酶活为767.27 U/g。菌株S-77被鉴定为东洋芽孢杆菌（Bacillus toyonensis），具有耐人工胃液、肠液效果及较好黏附于宿主肠壁细胞的能力，对抗生素敏感，可用于棉籽粕生物脱毒。

Isolation,identification and in vivo colonization of free gossypol-degrading strain

The efficient free gossypol-degrading strains were isolated and screened from quinoa stem leaf and tomato rod, to provide an excellent strain for biological detoxification of cottonseed meal. The free gossypol-degrading and protease-producing ability of the screened strains were tested, and in vivo colonization ability was further investigated by simulated gastric juice and simulated intestinal fluid tolerance tests, as well as antibiotics sensitivity test and surface characteristics test. The screened strain was identified by morphological observation, physiological and biochemical test and 16S rDNA sequence analysis. The results showed that a Bacillus strain with efficient free gossypol-degrading was obtained and numbered as S-77, with the free gossypol removal rate of 81.30% and the protease activity of 767.27 U/g. The strain S-77 was identified as Bacillus toyonensis, which was resistant to simulated gastric juice and intestinal fluid and had the ability to better adhere to the host intestinal parietal cells. The strain S-77 was sensitive to antibiotics, and could be used for biological detoxification of cottonseed meal.