泡菜中乳酸菌的分离及其苯乳酸产量研究

从泡菜中分离纯化得到2株乳酸菌LMD和LRA2,均能产乳酸、革兰氏染色阳性、接触酶阴性。经系统发育分析,结合菌落形态、细胞形态、生化反应试验,确定菌株LMD和LRA2为肠膜明串珠菌。菌株LMD和LRA2的苯乳酸产量和苯丙氨酸的添加量与培养时间呈正相关。在含0.16 %苯丙氨酸的MRS液体培养基中,培养72 h,菌株LMD的苯乳酸产量为0.144 7 mg·mL^-1,菌株LRA2的苯乳酸产量为0.158 5 mg·mL^-1。

Phenyllactic Acid-producing Activity of Lactic Acid Bacteria from Pickled Vegetable

Two strains of lactic acid bacteria, strain LMD and LRA2, were obtained from pickled vegetable. Two strains were gram-positive, lactic acid-producing, and catalase-negative. Based on morphological, physiological, biochemistry test and 16S rDNA sequencing analysis, LMD and LRA2 were identified as Leuconostoc mesenteroides. The phenyllactic acid （ PLA） yield increased with increasing phenylalanine （PPA） concentration and incubation time. After 72h in-cubation, strain LMD in MRS broth containing 0. 16% PPA produced 0. 1447 mg·mL-1 PLA, while LRA2 did 0. 1585mg·mL-1 PLA.