김치유산균의 프로바이오틱 특성 조사

Abstract

A total of 10 strains of lactic acid bacteria (LAB) was isolated from Kimchi were characterized for probiotic properties. Acid and artificial gastric juice tolerance of these 10 strains of LAB were investigated. The result of viability test in acid and artificial gastric juice, strains Lactobacillus plantarum AF1 and Lactobacillus plantarum NO1 showed high viability (maintain initial viable cell, 10⁸∼10⁹ CFU/mL) for 2 hours in 0.05 M sodium phosphate buffer (pH 2.5), and artificial gastric juice. The ashesion of 10 strains of LAB was studied using Caco-2 cell lines as an in vitro model for intestinal epithelium. The two most adhesive strains were Leuconostoc kimchii GJ2 and Pediococcus pentosaceus MP1. Adhesion of all the strains was dependent of the number of bacteria used. This study was also carried out to investigate the cell surface hydrophobicity (CSH) and cell autoaggregation ability of 10 strains of LAB. Among the tested strains, Lb. plantarum AF1 and Lb. plantarum NO1 were highly observed hydrophobicity and cell autoaggregation, compared to Lactobacillus rhmanosus GG as control. However, no correlation could be observed cell surface hydrophobicity and autoaggregation between adhesion abilities of the tested strains of LAB. The enzyme profiling is an important factor for selection of strains as starter cultures. The enzymatic potential of the strains was evaluated using the API ZYM kit. Leucine arylamidase activity was strong for P. pentosaceus MP1, the mean value being > 40 nmole of substrate. Strong β-galactosidase activities were observed by Lb. buchneri MS, Lb. plantarum AF1 and Lb. plantarum NO1. To obtain antibiotic susceptibilities of LAB, minimum inhibitory concentration (MIC) of 8 antibiotics for 10 LAB isolates from Kimchi were determined. All strains tested were sensitive to ampicillin, gentamacin, kanamycin, streptomycin, erythromycin, clindamycin, tetracyclline and chloramphenicol. Taken together these results, Lb. plantarum NO1 isolated Kimchi may be used as probiotic strains.