青海地区产共轭亚油酸乳酸菌分离及其对青贮全株玉米品质的影响

Isolation of Lactobacillus producing conjugated linoleie acid in Qinghai area and its effect on quality of whole corn silage

以青海高寒地区青贮玉米(Zea mays)为材料,从中分离出产共轭亚油酸(CLA)的微生物并对其进行形态学观察和16S rDNA基因序列分析,同时将该菌作为青贮菌剂回接到全株玉米中,在实验室用青贮袋青贮40 d,研究该菌作为青贮添加剂替代常规青贮菌剂处理全株玉米对其青贮品质及营养成分影响。结果表明,这株分离得到的产CLA的微生物为植物乳杆菌(Lactobacillus plantarum),命名为ANCLA2。从感官角度评价该菌青贮全株玉米效果和常规植物乳杆菌青贮效果相当,能有效提高青贮中乳酸(LA)和乙酸(AA)含量,降低青贮料pH且抑制了青贮料中氨态氮(NH3-N)含量;但ANCLA2菌较高程度地降低了全株玉米干物质(DM)和粗蛋白(CP)含量,且随着接种量增加,干物质损失量增高;中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)含量显著高于对照组(P<0.05),粗脂肪(EE)和CLA含量高于其他处理组(P<0.05)。综上,ANCLA2菌在保证全株玉米青贮效果的同时,能提高粗脂肪和CLA含量。

A bacteria which could convert linoleic acid to conjugated linoleie acid (CLA),was screened from the silage in Qinghai Province. The bacteria was identified by morphological observation and 16S rDNA gene sequence analysis. The bacteria was inoculated to the whole plant corn and was cultured 40 days in seal silage bags. The effects of bacteria on the organoleptic properties and chemical compositions of the whole corn silages were assessed. The results showed that this bacteria strain producing CLA was Lactobacillus plantarum and named ANCLA2. It can effectively improve the content of lactic acid and acetic acid in silage, reduce pH and inhibit the ammonia nitrogen (NH3-N) content, but the dry matter (DM) content of whole plant corn and the crude protein (CP) significantly decreased, and the more the dry matter was lost with the inoculation increasing; neutral detergent fiber (NDF) and acid detergent fiber (ADF) were significantly higher than the control group (P < 0.05), crude fat (EE) and CLA content higher than other treatment groups (P < 0.05). In summary, ANCLA2 bacteria not only ensure the effect of the whole plant corn silage, but also improve the content of crude fat and CLA.