Abstract:At present, the yield of plantaricin produced by Lactobacillus plantarum through conventional fermentation is relatively low. Therefore, optimization of plantaricin production conditions and methods of isolation and purification is an effective approach to improve its yield. In this study, three strains of L. plantarum were chosen as fermentation agents and the effects of fermentation time, temperature, initial pH of the culture, and medium composition on the production of plantaricin were investigated. Based on the results of such optimization techniques, five different methods for separation and purification of plantaricin were explored and the best combination was identified as follows: fermentation time of 28~35 h; temperature at 30 ℃~37 ℃; initial pH of the culture medium at 6.5~7.0; 10 g/L glucose and 10 g/L sucrose as carbon sources; 10 g/L peptone, 5 g/L beef cream, and 5 g/L yeast powder as nitrogen sources; 2 g/L potassium hydrogen phosphate, 0.2 g/L magnesium sulfate, 0.05 g/L manganese sulfate, 2 g/L ammonium citrate, and 5 g/L sodium acetate as inorganic salts; and 1 ml/L tween-80 as emulsifier. Under these optimized culture conditions plantaricin yield increased by at least 1.5 times. The optimal separation method identified as ultrafiltration, where the recovery rate reached 71% after fermentation broth was extracted by ultrafiltration. Results from this study thus provide theoretical and technical evidence for increasing plantaricin yield which will be useful for industrial applications.
