欢迎访问《草业学报》官方网站,今天是 分享到:

草业学报 ›› 2018, Vol. 27 ›› Issue (8): 118-129.DOI: 10.11686/cyxb2017374

• 研究论文 • 上一篇    下一篇

小花棘豆与玉米混贮微生物特性及脱除苦马豆素乳酸菌的筛选

陶雅1, 2, 李峰1, 孙启忠1, 柳茜3, 高润1, 徐春城2, *   

  1. 1.中国农业科学院草原研究所,内蒙古 呼和浩特 010010;
    2.中国农业大学工学院,北京 100083;
    3.凉山彝族自治州畜牧兽医研究所,四川 西昌 615042
  • 收稿日期:2017-09-06 修回日期:2017-11-28 出版日期:2018-08-20 发布日期:2018-08-20
  • 通讯作者: E-mail: xucc@cau.edu.cn
  • 作者简介:陶雅(1982-),女,内蒙古呼和浩特人,副研究员,硕士。E-mail: taoya2001@126.com
  • 基金资助:
    优质饲草供给及草畜种养循环关键技术研发(2017YFD0502100),中国农业科学院创新工程(CAAS-ASTIP-IGR 2015-02)和内蒙古自治区自然科学基金项目(2014MS0368)资助

Microbial characteristics of Oxytropis glabra and corn mixed silage and screening for swainsonine-removing lactic acid bacteria

TAO Ya1, 2, LI Feng1, SUN Qi-zhong1, LIU Qian3, GAO Run1, XU Chun-cheng2, *   

  1. 1.Grassland Research Institute, Chinese Academy of Agricultural Science, Hohhot 010010, China;
    2.College of Engineering, China Agricultural University, Beijing 100083, China;
    3.Institute of Animal and Veterinary Sciences of Liangshan Prefecture, Xichang 615042, China
  • Received:2017-09-06 Revised:2017-11-28 Online:2018-08-20 Published:2018-08-20

摘要: 旨在探讨小花棘豆与玉米按不同比例混贮对微生物特性及乳酸菌多样性影响,挖掘具有脱除苦马豆素活性的乳酸菌,为小花棘豆青贮饲料的开发利用提供理论参考。以小花棘豆和全株玉米为原料,按不同比例10:0(T1)、9:1(T2)、8:2(T3)7:3(T4)、6:4(T5)、5:5(T6)、4:6(T7)、0:10(T8)混合青贮,室温发酵60 d,检测青贮前、后微生物种类、数量变化,鉴定分离出的乳酸菌,并测定其对苦马豆素的脱除率。试验结果:1)原料中乳酸菌数量随着玉米混入量的增加逐渐升高,青贮饲料各处理间乳酸菌数量无显著差异;原料中的肠细菌各处理间无显著差异,经过青贮发酵后肠细菌均未检测到;好氧细菌数量在原料和青贮饲料中均随着玉米比例的增加逐渐减少;酵母菌数量在各处理间均无显著差异;原料中的霉菌数量随着玉米混入比例增加逐渐增加,而青贮饲料中的霉菌数量均在检出线以下。2)从小花棘豆与玉米混贮的原料中共分离得到乳酸菌菌株4株,经鉴定属于Lactococcus lactis subsp. hordniaeLactococcus lactis subsp. lactisLactococcus taiwanensis 3种;从青贮饲料中分离出乳酸菌菌株9株,经鉴定属于Lactobacillus plantarum subsp. plantarumLactobacillus brevisLactobacillus pentosusLactobacillus amylovorus 4种,当玉米混入比例升高时,原料中乳酸菌多样性有所增加,而青贮饲料中乳酸菌多样性有所下降。3)不同乳酸菌菌株对苦马豆素的脱除率均高于85%,其中菌株JD6E、JD4D、JD10D、JD2E和JD1F对苦马豆素的脱除率高达100%。经过热处理后,菌株JD10D和JD2E对苦马豆素的脱除率分别为100%和97.76%,而其他菌株对苦马豆素的脱除率下降31.76%~100%,其中菌株JD6D和JD1E经过热处理后对苦马豆素的脱除率分别下降到2.17%和0。结果表明,小花棘豆与玉米混贮可以增加青贮原料中乳酸菌的数量及多样性,降低青贮饲料和原料中好氧细菌的数量,有助于提高青贮成功率;乳酸菌对苦马豆素具有良好的脱除效果,菌株JD10D和JD2E对苦马豆素的吸附脱除作用最强,而菌株JD6D和JD1E对苦马豆素的降解作用最强,均可用作小花棘豆青贮脱除苦马豆素的发酵菌株。

关键词: 小花棘豆, 混贮, 微生物特性, 苦马豆素脱除

Abstract: To establish a method to use Oxytropis glabra as a silage crop, the influence of different ratios of O. glabra and corn (Zea mays) on microbial characteristics and the diversity of lactic acid bacteria in silage were investigated. We also screened for swainsonine-removing lactic acid bacterial strains. The proportions of O. glabra:corn in the eight treatments were as follows: 10:0 (T1), 9:1 (T2), 8:2 (T3), 7:3 (T4), 6:4 (T5), 5:5 (T6), 4:6 (T7) and 0:10 (T8). The microbial community structure and quantities were analyzed after fermentation of silage for 60 days. Lactic acid bacterial strains were isolated from fresh material and silage, and their removal rates of swainsonine were determined. The main results were as follows: 1) The numbers of lactic acid bacteria in fresh material increased with increasing proportions of corn, but did not differ significantly among the silage materials. The mixing ratio did not affect the numbers of coliform bacteria in the fresh material, and coliform bacteria could not be detected after fermentation. The numbers of aerobic bacteria in fresh and silage material decreased with increasing proportions of corn. The amount of yeasts was not affected by the ratio of O. glabra and corn. When more corn was added, the number of molds increased, but molds were beneath the limits of detection in the silage materials. 2) Four lactic acid bacterial strains were isolated from the fresh material: Lactococcus lactis subsp. Hordniae, Lactococcus lactis subsp. Lactis, and Lactococcus taiwanensis. Nine lactic acid bacterial strains were isolated from silage material, including Lactobacillus plantarum subsp. Plantarum, Lactobacillus brevis, Lactobacillus pentosus, and Lactobacillus amylovorus. As the proportion of corn increased, the diversity of lactic acid bacteria increased in fresh material but decreased in silage. 3) The swainsonine-removing rates of all lactic acid bacterial strains were higher than 85%, and 100% for strains JD6E, JD4D, JD10D, JD2E, and JD1F. After pretreatment of silage with boiling water, the swainsonine-removing rates of strains JD10D and JD2E were 100% and 97.76% respectively, but those of other strains decreased by 31.76%-100%. The swainsonine-removing rates of strains JD6D and JD1E dropped to 2.17% and 0, respectively, after the heat treatment. These results showed that with increasing proportions of corn in the mixture, the quantities and diversity of lactic acid bacteria in fresh material increased and the populations of aerobic bacteria both in raw material and silage decreased, which increased the success rate of ensilage. Some lactic acid bacteria were able to remove swainsonine. Strains JD10D and JD2E had the best ability to bind swainsonine, and strains JD6D and JD1E showed the best swainsonine-degradation ability. These four strains can be used as biological detoxification agents to remove swainsonine from O. glabra silage.

Key words: Oxytropis glabra, mixed silage, microbial characteristics, swainsonine-removing