Rumen fermentation and acetogen population changes in response to an exogenous acetogen TWA4 strain and Saccharomyces cerevisiae fermentation product  

外源添加产乙酸菌和酿酒酵母发酵物对瘤胃发酵特性及产乙酸菌菌群结构的影响（英文）

作　　者：Chun-lei YANG Le-luo GUAN Jian-xin LIU Jia-kun WANG 

机构地区：[1]Institute of Dairy Science, Mo E Key Laboratory of Molecular Animal Nutrition, College of Animal Sciences,Zhejiang University [2]Department of Agricultural, Food & Nutritional Science, Faculty of Agricultural, Life & Environmental Sciences,University of Alberta

出　　处：《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》2015年第8期709-719,共11页浙江大学学报（英文版）B辑（生物医学与生物技术）

基　　金：supported by the Fundamental Research Funds for the Central Universities(No.2011XZZX006);the National Natural Science Foundation of China(No.31172229);the University of Alberta Research Internship Program Summer 2012,Canada

摘　　要：The presence of yeast cells could stimulate hydrogen utilization of acetogens and enhance acetogenesis. To understand the roles of acetogens in rumen fermentation, an in vitro rumen fermentation experiment was conducted with addition of acetogen strain （TWA4） and/or Saccharomyces cerevisiae fermentation product （XP）. A 2×2 factorial design with two levels of TWA4 （0 or 2×10^7 cells/ml） and XP （0 or 2 g/L） was performed. Volatile fatty acids （VFAs） were increased （P〈0.05） in XP and TWA4XP, while methane was increased only in TWA4XP （P〈0.05）. The increase rate of microorganisms with formyltetrahydrofolate synthetase, especially acetogens, was higher than that of methanogens under all treatments. Lachnospiraceae was predominant in all acetogen communities, but without close acetyI-CoA synthase （ACS） amino acid sequences from cultured isolates. Low-Acetitomaculum ruminis-like ACS was predominant in all acetogen communities, while four unique phylotypes in XP treatment were all amino acid identified Iow-Eubacterium limosum-like acetogens. It differs to XP treatment that more Iow-A. ruminis-like and less Iow- E. limosum-like sequences were identified in ＂I＇WA4 and TWA4XP treatments. Enhancing acetogenesis by supple- mentation with an acetogen strain and/or yeast cells may be an approach to mitigate methane, by targeting proper acetogens such as uncultured Iow-E. limosum-like acetogens.目的:酵母可以促进产乙酸菌利用氢生成乙酸。为了解产乙酸菌在瘤胃发酵中的作用,本试验研究了产乙酸菌单独添加及其与酿酒酵母发酵物联合添加对瘤胃发酵特性及产乙酸菌菌群结构的影响。创新点:通过瘤胃甲烷生成量与产乙酸菌菌群结构关联,揭示降低瘤胃甲烷生成的新途径。方法:试验采用2×2双因素试验设计,产乙酸菌TWA4的添加量为0和2×107 cells/ml,酿酒酵母发酵物XP的添加量为0和2 g/L。结论:瘤胃体外发酵研究发现,单独添加XP以及TWA4和XP联合添加可增加挥发性脂肪酸产量(P<0.05),TWA4和XP联合添加显著增加了甲烷生成量(P<0.05)。单独添加TWA4、XP以及两者联合添加均增加了含有甲酰四氢叶酸合成酶的微生物的数量,尤其是产乙酸菌的数量,这类微生物的增长幅度高于产甲烷菌。各处理产乙酸菌均以Lachnospiraceae为主,但与已培养的微生物的相似性较低。与Acetitomaculum ruminis低相似性的一类未知的产乙酸菌在各处理中均占优势,但XP的添加增加了与Eubacterium limosum低相似未知产乙酸菌的数量。与XP不同,TWA4及其与XP的联合添加使与A.ruminis低相似性的一类未知的产乙酸菌的数量增加,与E.limosum低相似未知产乙酸菌的数量降低。因此,添加与E.limosum低相似的未知产乙酸菌和(或)酵母可能是降低瘤胃甲烷生成的一种有效途径。

关 键 词：ACETOGEN Saccharomyces cerevisiae fermentation product Rumen fermentation METHANOGEN 

分 类 号：TQ920.1[轻工技术与工程—发酵工程]