Processability of four strains of lactic acid bacteria

Three kinds of common antibiotic,tetracycline,erythromycin and chloromycetin were selected for measuring the maximum tolerated concentration( MTC) of four strains of lactic acid bacteria in different antibiotics.The in vitro gastrointestinal environmental tolerance of the four strains of lactic acid bacteria were compared.Four strains of lactic acid bacteria had different levels of resistance to three kinds of antibiotics,and the maximum tolerated concentration were obtained: Leuconostoc mesenteroides subsp.Mesenteroides BD1710,MTC of tetracycline and chloramphenicol was 1,2 μg/m L respectively; Lactobacillus plantarum ST-Ⅲ,MTC of chloramphenicol was 1μg/mL; Lactobacillus casei BD0054,MTC of tetracycline and chloramphenicol was 1 μg/mL; Lactobacillus casei LC2W,MTC of chloramphenicol was 1 μg/m L. Four strains of lactic acid bacteria were intolerance to erythromycin.The results of simulated gastrointestinal environment experiment demonstrated: in the simulated gastric juice environment,the growth of ST-Ⅲ and LC2W were unaffected,great harm were caused to BD0054;Under the environment of simulated intestinal juice,the growth of ST-Ⅲ and BD1710 were unaffected,LC2W do not endure.When four strains of bacteria were treated with high temperatures,EDTA will enhance the damage to these bacteria.After freeze drying treatment added with 10% skim milk,the survival rate were 90% ~95%.