Phân lập và tuyển chọn vi khuẩn lactic có họat tính kháng <i>Vibrio parahaemolyticus</i> từ nội tạng tôm thẻ chân trắng (<i>Litopenaeus vannamei</i>)

Abstract

     The lactic acid bacteria (LAB) are used to create probiotics in shrimp farming due to beneficial effects such as supporting digestion and inhibiting pathogenic bacteria in shrimp. This study aims to acquire certain strains of lactic acid bacteria against Vibrio parahaemolyticus from gut of White leg shrimp (Litopenaeus vannamei) in Nhon Trach district, Dong Nai province in order to produce probiotic for the shrimp basically. The research was carried out by isolating some strains on pre-selective medium MRS Broth + 50mg/l Nystatin and selective medium MRS agar + 0,5% CaCO₃; determining lactic acid by the Uffelmann reagent; selecting strains with high antibacterial activity; identifying by biochemical and molecular biology methods. Next, Vibrio parahaemolyticus antibacterial ability of the identified strains was investigated. The results showed that Lactobacillus salivariu LIITA1.2.2, Lactobacillus reuteri LIVTA2.4.1 and Lactobacillus plantarum LVIITA3.3.9 were selected. These strains could produce lactic acid and resistant to V. parahaemolyticus in density of 10⁵ cfu /ml, 10⁶ cfu/ml and 10⁷ cfu/ml.

Keywords: Probiotic, lactic acid bacteria (LAB), Vibrio parahaemolyticus, Lactobacillus rhamnosus, Lactobacillus salivarius, Lactobacillus reuteri, Litopenaeus vannamei