식해에서 분리한 유산균의 특성과 유산균 배양액의 항산화 작용 및 콜레스테롤 저감 활성

Abstract

The objective of this study was aimed to evaluate the biological functions such as antioxidant and cholesterol-lowering activities of lactic acid bacteria (LAB) isolated from Korean traditional fermented seafood, Sik-hae. A total of nine LAB strains were isolated from the fermented seafood, which was purchased from traditional markets in Gyeongju-city, Pohang-city, Yeongdeok-gun, and Gangneung-city. These LAB isolates were identified based on the biochemical analysis using the API 50 CHL system and 16S rRNA gene sequencing technique. The probiotic characteristics of LAB isolates were carried out by several assays such as acid, bile, and salinity resistance, and also the antioxidant activity. The antioxidant activities of LAB isolates were analyzed using 2, 2 diphenyl-1-picrylhydrazyl and 2-azinobis (3-ethylbenzthiazoline)-6-sulfonic acid radical scavenging assay as well as ferric reducing antioxidant power assay and oxygen radical absorbance capacity assay. The safety of LABs was also evaluated by determining the hemolysis assay, antibiotic resistance, and amino acid decarboxylase activity. Results show that LABs did not exhibit α- or β-hemolysis on the blood agar plate. The antibiotic resistance properties of LABs were examined using erythromycin, kanamycin, streptomycin, tetracycline, penicillin G, and ampicillin. Furthermore, it was not observed the productions of any biogenic amines from LAB isolates. Except for Leuconostoc citreum S-01, LAB isolates also showed a proteolytic activity. The cholesterol-lowering effect by LAB isolates was observed at varying levels ranging from 45.3 to 81.6%. Among all LAB isolates, L. mesenteroides S-09 was found to have excellent acid resistance, bile resistance, salinity resistance, antioxidant activity, and cholesterol reduction ability. Thus, the present study suggests that the LAB strains isolated from Sik-hae can be used as a potential microbial source for the development of fermented seafood products in the future.