鳄鱼肠中一株乳酸菌分离鉴定及活性物质的初步分析

Isolation and Identification of a Lactobacillus in Crocodile Intestines and Preliminary Analysis of its Active Substances

利用含有0.3%CaCO_3的MRS分离培养基,从鳄鱼肠道分离得到1株产酸能力强的菌株,命名E02,通过形态观察,并进行生理生化特征分析,初步鉴定为乳杆菌。以大肠杆菌、副溶血性弧菌、金黄色葡萄球菌、枯草芽孢杆菌、单核细胞增生李斯特菌和黑曲霉作为指示菌,采用牛津杯双层平板法测其发酵产物抑菌活性。通过用乳酸调节与原发酵液相同pH的MRS液体培养基,并与原发酵液作抑菌活性对比,进行抑菌活性物质初步分析。实验结果表明,菌株E02发酵产物的抑菌物质主要是酸,只有少部分是其他活性物质。

A strain with strong acid-producing ability was isolated from the intestinal tract of the crocodile using the MRS isolation medium containing 0.3%CaCO3.The strain was named E02.Through morphological observation and physiological and biochemical characteristics analysis,it was initially identified as Lactobacillus.Escherichia coli,Vibrio parahaemolyticus,Staphylococcus aureus,Bacillus subtilis,Listeria monocytogenes,and Aspergillus niger were used as indicator bacteria to measure the antibacterial activity of their fermentation products using the Oxford Cup double-layer plate method.By using lactic acid to adjust the MRS liquid medium having the same pH as the original fermentation broth and comparing with the original fermentation broth for antibacterial activity,a preliminary analysis of the antibacterial active substances was conducted.The experimental results show that the antibacterial substances of the fermentation product of strain E02 are mainly acid,and only a small part is other active substances.