青贮饲料中优良乳酸菌的分离鉴定及其生物学特性研究

Isolation and Identification of Excellent Lactic Acid Bacteria from Silage and Its Biological Characteristics Research

为筛选优良的青贮饲料添加剂,采用平板分离法从青贮饲料中分离乳酸菌,通过细菌形态学、生理生化特征鉴定和16S rRNA基因序列分析相结合的方法对分离出的细菌进行鉴定。通过产酸性试验和抑菌试验对分离出来的12株乳酸菌进行筛选,并对筛选出的6株乳酸菌进行生物学特性比较。结果显示,5株为戊糖片球菌,4株为植物乳杆菌,1株为发酵乳杆菌,1株为肠系膜明串珠菌肠膜亚种,1株为屎肠球菌;菌株B1-6、B1-7、B2-3、B2-8、B3-1、B5-2的产酸能力和抑菌效果较好;菌株B1-7和B5-2生长最快,8 h后进入稳定期,其余菌株14 h后进入稳定期;菌株B1-7在培养温度高于45℃,培养基pH>10和含盐量>0.08g/mL时不再生长,其余菌株均具有良好的抗逆性具备青贮潜力,可作为秸秆青贮的生物添加剂做进一步研究。

To screen excellent microbials for silage additive usage,12 bacteria strains were isolated from the silage.According to the results of morphological observation,physiological and biochemical tests,and sequence analysis of the 16S rRNA gene of the strains isolated,6 strains were screened and compared through acid yield tests and bacteriostatic tests.The results showed 5 strains werePediococcus pentosaceus,4 strains were Lactobacillus plantarum,1 strain was Lactobacillus fermentum,1 strain was Leuconostoc mesenteroides subsp.mesenteroides,1 strain wasEnterococcus faecium;Strain B1-7 and B5-2 which reached a stable period after 8 h were fastest-growing,others were 14 h;The B1-7 stain no longer grow at temperature higher than 45℃,medium pH10,salinity0.08 g/mL.Other stains could be used as bio-straw silage additives to do further research which showed strong resistance and silage potential.