苯乳酸生产菌的筛选及鉴定

Screening and identification of phenyllactic acid-producing bacteria

苯乳酸是一种具有宽广抑菌谱的新型生物保鲜剂,为筛选得到苯乳酸高产菌株,采用改良的碳酸钙溶解圈法和抑菌圈法,从自然环境中采集的50个样品中分离筛选得到2株高产苯乳酸的乳酸菌,分别命名为BLPC002和SCPC008,并对其进行了初步鉴定。结果显示,BLPC002和SCPC008在以苯丙氨酸为底物的条件下,摇瓶发酵苯乳酸产量分别为358 mg/L和333 mg/L,较改良前不到100 mg/L有明显的提高,说明改良后的筛选方法更加高效、准确。进一步通过对菌株形态和16S rDNA序列分析初步鉴定,均为植物乳杆菌。

Phenyllactic acid is a new biological preservative with broad antibacterial spectrum.In order to obtain high yield lactic acid bacteria,2 lactic acid bacteria strains with high phenyllactic acid yield were isolated from 50 samples in different environment with the modified methods of dissolving calcium ring and bacteriostatic circle,which were named respectively as BLPC002 and SCPC008,and the strains were identified.The results showed that the yield of phenyllactic acid in shake flask fermentation with phenylalanine as substrate was 358 mg/L and 333 mg/L,respectively.The yields of phenyllactic acid were evidently improved compared with less than 100 mg/L before modification.It indicated that the modified method was more efficient and accurate.The strains were identified as Lactobacillus plantarum by morphological analysis and 16S rDNA sequencing.