Na Na, Qili Moge, Wu Nier, Sun Lin, Xu Haiwen, Zhao Yi, Wei Xiaobin, Xue Yanlin, Tao Ya
Inner Mongolia Key Laboratory of Microbial Ecology of Silage, Inner Mongolia Engineering Research Center of Development and Utilization of Microbial Resources in Silage, Inner Mongolia Academy of Agriculture and Animal Husbandry Science, Hohhot, China.
College of Foreign Languages, Inner Mongolia University of Finance and Economics, Hohhot, China.
Front Microbiol. 2022 Apr 22;13:836899. doi: 10.3389/fmicb.2022.836899. eCollection 2022.
The aim of this study was to determine the effects of six common commercial lactic acid bacteria (LAB) additives [A1, , , and ; A2, and ; A3, and ; A4, , , , and ; A5, (producing feruloyl esterase); and A6, , , β-glucanase, and xylanase] on the bacterial community and fermentation quality of alfalfa silage. Alfalfa was harvested at the squaring stage, wilted in the field for 24 h, and ensiled without any additives (Control) or with A1, A2, A3, A4, A5, or A6. Microbial counts, bacterial community, fermentation parameters, and nutritional composition were determined after ensiling for 90 days. The total abundance of LAB genera on alfalfa pre-ensiling was 0.38% in bacterial community. The abundances of , , and in the Control silage were 42.18, 40.18, and 8.09% of abundance, respectively. The abundances of in A1-, A2-, A3-, A4-, and A5-treatments were 89.32, 92.93, 92.87, 81.12, and 80.44%, respectively. The abundances of and in A6-treatment were 70.14 and 24.86%, respectively. Compared with Control silage, LAB-treated silage had lower pH and less ammonia nitrogen and water-soluble carbohydrates concentrations ( < 0.05). Further, the A5- and A6-treatments contained lower neutral detergent fiber, acid detergent fiber, and hemicellulose than other treatments ( < 0.05). Overall, LAB genera were presented as minor taxa in alfalfa pre-ensiling and as dominant taxa in alfalfa silage. Adding LAB additives improved the fermentation quality and altered the bacterial community of alfalfa silage. The main bacterial genera in Control silage were , , and . dominated the bacterial communities of A1-, A2-, A3-, A4-, and A5-treatments, while and were dominant bacterial genera in A6-treatment. Inoculating A5 and A6 degraded the fiber in alfalfa silage. It is necessary to ensile alfalfa with LAB inoculants.
本研究旨在确定六种常见的商业乳酸菌（LAB）添加剂[A1， ， ， 和 ；A2， 和 ；A3， 和 ；A4， ， ， ，和 ；A5， （产生阿魏酸酯酶）；以及A6， ， ，β-葡聚糖酶和木聚糖酶]对苜蓿青贮饲料细菌群落和发酵品质的影响。苜蓿在现蕾期收获，在田间萎蔫24小时，然后不添加任何添加剂（对照）或添加A1、A2、A3、A4、A5或A6进行青贮。青贮90天后测定微生物数量、细菌群落、发酵参数和营养成分。苜蓿青贮前细菌群落中LAB属的总丰度为0.38%。对照青贮饲料中 、 和 的丰度分别占丰度的42.18%、40.18%和8.09%。A1、A2、A3、A4和A5处理中 的丰度分别为89.32%、92.93%、92.87%、81.12%和80.44%。A6处理中 和 的丰度分别为70.14%和24.86%。与对照青贮饲料相比，LAB处理的青贮饲料pH值较低，氨态氮和水溶性碳水化合物浓度较低（P<0.05）。此外，A5和A6处理的中性洗涤纤维、酸性洗涤纤维和半纤维素含量低于其他处理（P<0.05）。总体而言，LAB属在苜蓿青贮前是次要类群，在苜蓿青贮饲料中是优势类群。添加LAB添加剂改善了苜蓿青贮饲料的发酵品质并改变了其细菌群落。对照青贮饲料中的主要细菌属为 、 和 。 在A1、A2、A3、A4和A5处理的细菌群落中占主导地位，而 和 是A6处理中的优势细菌属。接种A5和A6可降解苜蓿青贮饲料中的纤维。用LAB接种剂对苜蓿进行青贮是必要的。
