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草业学报 ›› 2022, Vol. 31 ›› Issue (7): 85-95.DOI: 10.11686/cyxb2021261

• 研究论文 • 上一篇    下一篇

瘤胃纤维素降解菌系对灭菌水稻秸秆结构性碳水化合物降解的影响

李君风(), 赵杰, 唐小月, 代童童, 董东, 宗成, 邵涛()   

  1. 南京农业大学草业学院饲草调制加工与贮藏研究所,江苏 南京 210095
  • 收稿日期:2021-06-29 修回日期:2021-09-08 出版日期:2022-07-20 发布日期:2022-06-01
  • 通讯作者: 邵涛
  • 作者简介:E-mail: taoshaolan@163.com
    李君风(1988-),女,甘肃临夏人,讲师,博士。E-mail: ljf126ff@126.com
  • 基金资助:
    国家自然科学基金青年项目(31901391);西藏农作物秸秆综合利用技术集成与示范(XZ201901NB07)

Effect of a rumen cellulolytic microbial consortium on the degradation of structural carbohydrate in sterile rice straw silage

Jun-feng LI(), Jie ZHAO, Xiao-yue TANG, Tong-tong DAI, Dong DONG, Cheng ZONG, Tao SHAO()   

  1. Institute of Ensiling and Processing of Grass,College of Agro-grassland and Science,Nanjing Agricultural University,Nanjing 210095,China
  • Received:2021-06-29 Revised:2021-09-08 Online:2022-07-20 Published:2022-06-01
  • Contact: Tao SHAO

摘要:

为了提高水稻秸秆的青贮发酵品质,本研究旨在从黑白花奶牛瘤胃中筛选出具有降解纤维素能力的兼性厌氧复合菌系,探讨其对水稻秸秆青贮过程中结构性碳水化合物降解及发酵品质的影响。试验采集了黑白花奶牛瘤胃内容物,经富集培养、刚果红染色初筛,耐酸诱导,滤纸降解复筛,酶活力测定,获得高效兼性厌氧纤维素降解复合菌系M6。试验设4个处理组:1)水稻秸秆直接自然青贮(CK)组;2)灭菌后水稻秸秆青贮(IRR)组;3)灭菌水稻秸秆接种复合乳酸菌(CLAB)青贮组;4)灭菌水稻秸秆接种复合菌系(M6)青贮组,分别于青贮3、6、15、45、60和90 d后开窖取样分析。结果表明,青贮3 d后,M6处理组pH始终低于其他各组,青贮第60天达到最低值(4.62)。青贮45 d后,M6处理组乳酸含量始终显著高于其他各组(P<0.05),且在青贮90 d达到最高值(23.90 g·kg-1 DM)。青贮15 d后,中性洗涤纤维、酸性洗涤纤维和纤维素含量在M6组均显著低于其他各组(P<0.05),且在第90天达到最低值。青贮60 d后,IRR和M6组保持较高水平的水溶性碳水化合物含量,其次为CLAB组。综上所述,复合菌系M6在水稻秸秆青贮过程中具有降解粗纤维和促进乳酸发酵的作用,添加纤维素降解复合菌系可有效改善水稻秸秆青贮发酵品质,为青贮添加剂的研发与应用提供了理论依据。

关键词: 纤维素降解复合菌系, 水稻秸秆, 发酵品质, 碳水化合物

Abstract:

In order to improve the fermentation quality of rice (Oryza sativa) straw silage, this study aimed to isolate a facultative anaerobic cellulolytic microbial consortium (i.e. a group of two or more rumen bacteria working symbiotically) from the rumens of black-and-white dairy cows and further evaluate its effect on the fermentation quality and structural carbohydrates degradation of rice straw silage. The cellulolytic microbial consortium (M6) was screened from rumen contents by continuous enrichment cultivation, Congo red staining, acid-resistant induction screening, secondary screening through filter paper degradation, and enzyme activity assay. Rice straw was treated with following: 1) Natural fermentation of non-irradiated rice straw (CK); 2) Irradiated rice straw ensiled directly (IRR); 3) Irradiated rice straw ensiled with combined lactic acid bacteria (CLAB); 4) Irradiated rice straw ensiled with the microbial consortium (M6). Each treatment was sampled randomly after 3, 6, 15, 45, 60 and 90 days of ensiling for laboratory analysis. It was found that the pH of M6 silages was lower than that of other silages after 60 days of ensiling, and reached the minimum (4.62) on day-60 of ensiling. After 45 days of ensiling, the lactic acid content of M6 silage was significantly (P<0.05) higher than that of other silages and reached the maximum (23.90 g?kg-1 DM) on the day-90 of ensiling. After 15 days of ensiling, the contents of neutral detergent fiber (NDF), acid detergent fiber (ADF) and cellulose in M6 silages were significantly (P<0.05) lower than those of other silages, and were lowest on day-90 of ensiling. After 60 days of ensiling, the IRR and M6 silages maintained higher levels of water-soluble carbohydrate content than other treatments, followed by the CLAB silage. In summary, the microbial consortium M6 is effective in degrading cellulose and promoting lactic acid fermentation of rice straw silage. The addition of this cellulolytic microbial consortium effectively improved the fermentation quality of rice straw. This work provides a theoretical basis for the development and application of a silage additive containing the M6 microbial consortium.

Key words: cellulolytic microbial consortium, rice straw, fermentation quality, water-soluble carbohydrate