Hou Meiling, Wang Zhijun, Sun Lin, Jia Yushan, Wang Shicong, Cai Yimin
College of Life Science, Baicheng Normal University, Baicheng, China.
Key Laboratory of Forage Cultivation, Processing and High Efficient Utilization of Ministry of Agriculture, Key Laboratory of Grassland Resources, Ministry of Education, College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot, China.
Front Microbiol. 2023 Jan 9;13:1072140. doi: 10.3389/fmicb.2022.1072140. eCollection 2022.
To prepare high-quality silage, we studied the chemical composition, silage fermentation, characterization, and identification of lactic acid bacteria (LAB) associated with the silage fermentation of native grass on the Inner Mongolian Plateau.
LAB were isolated from fresh native grass and their silage, and silages were prepared using a small-scale fermentation system with 2-3 cm length in plastic bags.
The dominant species of native grasses used were , , , and , which contained 47.83-59.43 % moisture, 55.12-67.74 % neutral detergent fiber (NDF), and 8.72-14.55 crude protein (CP), and these nutrients did not change greatly during ensiling. Good preservation with a relatively low pH (below 4.44) and high ( < 0.05) lactic acid content (>0.58) was obtained after ensiling. Based on the morphological and biochemical characteristics, these isolates were divided into 12 groups (A-L). All isolate strains were gram-positive and catalase-negative bacteria that produce lactic acid from glucose. Group A-K were cocci, while group L was rod-shaped. Group A-E formed D-lactic acid, but group H-K formed L-lactic acid, and other groups formed DL-lactic acid. Group A-E were heterofermentative, and Group F-L were homofermentative types of LAB. According to the 16S rRNA gene sequences analysis, strains were identified as genus (A, B, and C), (D, E), (F, G), (H, I, J and K), and (L). (E.) (29.17%, percentage of total isolates) and (18.75%) were the most frequently occurring dominant species.
This study suggests that the native grasses contained abundant LAB species, and they can be used as good-quality silages in animal husbandry. In addition, the strains and were the most frequently isolated from native grass silages as dominant species which can be a potentially excellent inoculant for native grass silage.
为制备高质量青贮饲料，我们研究了内蒙古高原天然牧草青贮发酵过程中相关的化学成分、青贮发酵、特性及乳酸菌（LAB）的鉴定。
从新鲜天然牧草及其青贮饲料中分离乳酸菌，并使用塑料袋中长度为2 - 3厘米的小规模发酵系统制备青贮饲料。
所使用的天然牧草的优势物种为 、 、 、 和 ，其含水量为47.83 - 59.43%，中性洗涤纤维（NDF）含量为55.12 - 67.74%，粗蛋白（CP）含量为8.72 - 14.55%，青贮过程中这些养分变化不大。青贮后获得了良好的保存效果，pH值相对较低（低于4.44），乳酸含量较高（ < 0.05）（>0.58）。根据形态和生化特征，这些分离株被分为12组（A - L）。所有分离菌株均为革兰氏阳性且过氧化氢酶阴性的细菌，能从葡萄糖产生乳酸。A - K组为球菌，而L组为杆状。A - E组形成D - 乳酸，但H - K组形成L - 乳酸，其他组形成DL - 乳酸。A - E组为异型发酵，F - L组为同型发酵类型的乳酸菌。根据16S rRNA基因序列分析，菌株被鉴定为 属（A、B和C）、 属（D、E）、 属（F、G）、 属（H、I、J和K）和 属（L）。 （E.） （占分离株总数的29.17%）和 （18.75%）是最常见的优势物种。
本研究表明天然牧草含有丰富的乳酸菌物种，它们可作为优质青贮饲料用于畜牧业。此外， 菌株和 菌株是天然牧草青贮饲料中最常分离出的优势物种，可能是天然牧草青贮的潜在优良接种剂。
