Effects of Facultative Anaerobic Cellulolytic Bacteria and Nitrogen-fixing Bacteria Isolated from Cow Rumen Fluid on Rumen Fermentation and Dry Matter Degradation in Vitro  

作　　者：Zhang Mei-mei Li Yan-fang Liu Da-sen 

机构地区：[1]College of Animal Sciences and Technology,Northeast Agricultural University,Harbin 150030,China [2]College of Science,Northeast Agricultural University,Harbin 150030,China

出　　处：《Journal of Northeast Agricultural University(English Edition)》2020年第1期49-59,共11页东北农业大学学报（英文版）

基　　金：Supported by China Agriculture Research System(CARS-37);Northeast Agricultural University Innovation Funding for Postgraduate(yjscx14007)。

摘　　要：The purpose of the paper was to study the effects of cellulolytic bacteria(CB)mixed with nitrogen-fixing bacteria(NFB)on fermentation in vitro.Nine CB strains and seven NFB strains were isolated from numen fluid of three Holstein cows.Based onhigher activity of cellulose or nitrogenase,three CB types[CB-2(KT725624),CB-5(KT725623)and CB-6(KT725622)]and one NFB type[NFB-3(KT735054)]were screened out,respectively.Two parts were included in this study.The first part explored the optimal mixed ratio of CB to NFB through inoculating filter paper medium with the bacteria of 2×10^5 cfu·mL^-1.According to CMCase and FPase activities in the medium,the ratio of 4 to 1 was proven to be more effective.In the second part,rumen fermentation in vitro was conducted at 4:1 of CB to NFB,aiming at studying the effects of mixed bacteria.Six groups were classified,namely,control group(no bacteria),Group 1(CB-2+NFB-3),Group 2(CB-5+NFB-3),Group 3(CB-6+NFB-3),Group 4(NFB-3)and Group 5(CB-6).All the experimental groups had the same amount of bacteria(4×10^6 cfu·mL^-1)in the fermentation liquid.Samples were collected at 2,4,8,12 and 24 h of incubation.Compared with the groups with CB or NFB alone,gas production,dry matter degradability and bacterial protein expressions in the mixed groups increased.However,NH3-N concentration decreased and p H was stable.Meanwhile,related values among three mixed groups were significantly different;values in Group 2 were the best.

关 键 词：RUMEN CELLULOLYTIC BACTERIUM nitrogen-fixing BACTERIUM mixed culture in VITRO fermentation 

分 类 号：S852.6[农业科学—基础兽医学]