碱性过氧化氢处理稻秸纤维对瘤胃体外发酵特性和微生物多样性的影响  

Effects of Alkaline Hydrogen Peroxide Treatment of Rice Straw Fiber onRuminal Fermentation Characteristics and Microbial Diversity in Vitro

作　　者：郭孟娇 高健 孙展英 杨承剑[2] 成艳芬 GUO Mengjiao;GAO Jian;SUN Zhanying;YANG Chengjian;CHENG Yanfen(National Center for International Research on Animal Gut Nutrition,Nanjing Agricultural University,Nanjing 210095,China;Buffalo Research Institute,Chinese Academy of Agricultural Sciences and Guangxi Zhuang Nationality Autonomous Region,Nanning 530001,China)

机构地区：[1]南京农业大学动物科技学院,动物消化道营养国际联合研究中心,南京210095 [2]中国农业科学院广西壮族自治区水牛研究所,南宁530001

出　　处：《动物营养学报》2024年第7期4739-4750,共12页CHINESE JOURNAL OF ANIMAL NUTRITION

基　　金：兰州大学中央高校基本科研业务费专项资金(lzujbky-2022-ct04);国家自然科学基金项目(32061143034)。

摘　　要：本试验旨在评估一种碱性过氧化氢处理稻秸纤维的体外瘤胃降解率及其对瘤胃发酵参数和微生物多样性的影响。以普通稻秸为对照,将碱氧处理获得的稻秸纤维体外发酵72 h,并分别在4、8、12、18、24、36、48和72 h时测定产气量;在0.5、4、12、24、48和72 h时,每组取6个发酵瓶采集发酵液,用于测定挥发性脂肪酸(VFA)、氨态氮(NH_(3)-N)和菌体蛋白(MCP)含量,收集剩余底物,用于纤维降解率的测定;收集72 h发酵底物于-80℃保存,用于后续DNA提取和高通量分析。结果表明:1)在发酵72 h时,稻秸纤维的干物质降解率是稻秸的1.64倍(P<0.05),中性洗涤纤维、酸性洗涤纤维、纤维素和半纤维素的降解率均显著高于稻秸(P<0.05)。稻秸纤维干物质开始降解时间短于稻秸,稻秸纤维在发酵4 h时出现降解而稻秸在发酵12 h时出现降解。2)扫描电镜结果表明,与稻秸相比,稻秸纤维结构更加松散,微生物黏附数量更多,发酵72 h消化更完全。3)稻秸纤维的发酵总产气量、总挥发性脂肪酸含量以及丙酸和异戊酸含量均极显著高于稻秸(P<0.01),甲烷产量/总产气量比例和丁酸、异丁酸和戊酸含量以及乙酸/丙酸比例均显著或极显著低于稻秸(P<0.05或P<0.01)。在发酵72 h时,稻秸纤维的细菌总数和MCP含量极显著高于稻秸(P<0.01),NH_(3)-N含量极显著低于稻秸(P<0.01)。4)α多样性结果表明,稻秸纤维菌群多样性显著高于稻秸(P<0.05)。在门水平上,微生物差异分析结果表明,稻秸纤维和稻秸中相对丰度大于1%的菌门无显著差异(P>0.05);在属水平上,稻秸纤维中瘤胃球菌属(Ruminococcus)、产乙酸糖发酵菌属(Saccharofermentans)和普雷沃氏菌科UCG-001(Prevotellaceae_UCG-001)等的相对丰度显著低于稻秸(P<0.05),未培养的毛螺菌科(unculured_Lachnospiraceae)、Probable_genus_10、拟杆菌目F082(Bacteroidales_F082)和毛螺菌科UCG-009(Lachnospiraceae_UCG-009)的相对丰度显著高于�The aim of this experiment was to evaluate the rumen degradation rate of rice straw fiber treated with alkaline hydrogen peroxide and its effects on rumen fermentation parameters and microbial diversity in vitro.Taking the normal rice straw as control,the rice straw fiber treated with alkaline hydrogen peroxide was fermented for 72 h in vitro and the gas production was measured at 4,8,12,18,24,36,48 and 72 h,respectively.At 0.5,4,12,24,48 and 72 h,six fermentation bottles were collected from each group to determine the contents of volatile fatty acid(VFA),ammonia nitrogen(NH_(3)-N)and microbial protein(MCP),and the remaining substrate was collected for the determination of fiber degradation rate.The fermentation substrate was collected at 72 h and stored at-80℃for subsequent DNA extraction and high-throughput analysis.The results showed as follows:1)the dry matter degradation rate of rice straw fiber was 1.64 times that of rice straw at 72 h of fermentation(P<0.05),and the degradation rates of neutral detergent fiber,acid detergent fiber,cellulose and hemicellulose were significantly higher than those of rice straw(P<0.05).The dry matter degradation time of rice straw fiber was shorter than that of rice straw.Rice straw fiber degradation occurred at 4 h and rice straw degradation occurred at 12 h.2)The scanning electron microscope results showed that compared with the rice straw,the fiber structure of rice straw was more loose,the number of microbial adhesion was more,and the digestion was more complete after 72 h of fermentation.3)The total gas production,total volatile fatty acid content and contents of propionate and isovalerate in rice straw fiber were extremely significantly higher than those in rice straw(P<0.01),and the ratio of methane production to total gas production,the contents of butyrate,isobutyrate and valerate,and the ratio of acetate to propionate were significantly or extremely significantly lower than those in rice straw(P<0.05 or P<0.01).At 72 h of fermentation,the total bacteria number and

关 键 词：稻秸纤维 纤维降解 瘤胃发酵 微生物多样性 体外 

分 类 号：S816[农业科学—饲料科学]