产苯乳酸乳酸菌的筛选及鉴定

Screening and Identification of Lactic Acid Bacteria Producing Phenyllactic Acid

[目的]研究产苯乳酸乳酸菌的筛选与鉴定。[方法]用双层培养基法从传统发酵制品中分离出115株乳酸菌,用双层平板法从中筛选出24株对啤酒酵母具有明显抑菌效果的菌株,然后通过高效液相色谱分析筛选产苯乳酸量最高的菌株,并对筛选的菌株进行形态学观察、生理生化鉴定以及菌株16S rDNA序列的测定与分析。[结果]对初筛的24株菌株发酵液进行高效液相色谱分析得到7株苯乳酸的产量>60 mg/L的菌株,其中菌株P421乳酸菌显示出最高的苯乳酸生产能力,苯乳酸产量可达80.5 mg/L。根据菌株P421的形态特征、生理生化特征和16S rDNA序列分析,将该菌株鉴定为植物乳杆菌(Lactobacillus plantarum)。[结论]从传统发酵制品中分离筛选得到1株产苯乳酸的菌株,建立了1种准确筛选苯乳酸生产菌的方法。

[Objective] The study aimed to research the screening and identification of lactic acid bacteria producing phenyllactic acid.[Method] The 115 lactic acid bacteria strains were separated from the traditional fermented products by using double-medium method.Among them,the 24 strains which had obvious bacteriostasis effect on beer yeast were screened by using double-layer plate method,and then the strain that could produce highest phenyllactic acid was screened and analyzed through HPLC method.The screened strains were made to for the observation on morphology,the identification on physiology and biochemistry,the measuration and analysis on strain 16S rDNA sequence.[Result] After the fermentation liquid of first screened 24 strains fermentation liquid were made for HPLC analysis,the 7 strains with the yield of phenyllactic acid more than 60 mg/L were obtained.In which,the strain P421 lactic acid bacteria showed the highest phenyllactic acid production capacity and its yield of phenyllactic was up to 80.5 mg/L.On base of the morphological character,physiology and biochemistry and 16SrDNA sequence analysis,this strain was identified as the Lactobacillus plantarum.[Conclusion] A strain of phenyllactic acid-producing was separated and screened in traditional fermented products and the method of accurately screening the phenyllactic acid producing bacteria was established.