饲料原料中两株优良乳酸菌的分离、筛选与鉴定

Isolation, screening and identification of two excellent lactic acid bacteria in feed materials

为获得性能优异的乳酸菌,对一些饲料原料中乳酸菌进行了筛选和鉴定,共获得了105株乳酸菌,通过形态学观察,16S rRNA基因序列分析以及生理生化试验等手段获取了有代表性的16株乳酸菌,通过产酸性能、酸耐受性、耐胆盐能力和抑菌效果等试验测定,共获得了2株性能优异的乳酸菌P16和C20。经鉴定,P16为戊糖片球菌(Pediococcus pentosaceus),对大肠杆菌K88(Escherichia coli CVCC 225)的抑菌能力较强,12 h发酵液pH值为3.36, 0.3%胆盐处理2 h存活率为82.00%;C20为希氏肠球菌(Enterococcus hirae)对指示菌金黄色葡萄球菌(Staphylococcus aureus ATCC 25923)的抑菌效果较好,发酵液12 h pH值为3.88,0.3%胆盐处理2 h存活率为97.67%;此外,P16和C20酸耐受性也相对较强,具备一定应用潜力。

In order to obtain lactic acid bacteria with excellent performn, lactic acid bacteria were screened and identified from several feed materials. Through morphological observation, combined with 16S rRNA gene sequence analysis and physiological and biochemical experiments, 16 representative strains of lactic acid bacterias were tested by acid production,acid tolerance, bile salt resistance and antibacterial effect. Two strains of lactic acid bacterias P16 and C20 with excellent performance were obtained. P16 was identified as Pediococcus pentosaceus and had strong antibacterial activity against E. coli k88(CVCC 225). At the same time, the pH value of the fermentation broth was 3.36 after cultured 12 h, and the survival rate was 82.00% after treated with 0.3% choline salt for 2 h. C20 had a better antibacterial effect against the indicator strain Staphylococcus aureus ATCC 25923, while the pH of the fermentation broth was 3.88 after cultured 12 h,and the survival rate was 97.67% after treated with 0.3% choline salt for 2 h;in addition, the tolerance of P16 and C20 acid was also relatively strong, with certain application potential.