EFFECT OF PREBIOTICS, INORGANIC SALTS AND AMINO ACIDS FOR CELL ENVELOPE PROTEINASE PRODUCTION FROM LACTOBACILLUS PLANTARUM LP69

Background. Cell-envelope proteinases (CEPs) can improve the texture and organoleptic characteristics of dairy products, and may also cause the release of bioactive peptides, which contribute to improving the host's health. Thus, the CEPs with high activity produced by L. plantarum has great potential in the development of functional dairy products. Methods. A single factor experiment was used to investigate the effects of prebiotics (inulin, stachyose, isomaltooligosaccharide, xylooligosaccharides, galactooligosaccharides and fructooligosaccharides), inorganic salts (Na2HPO4, NaH2PO4, K2HPO4, KH2PO4, CH3COONa and C6H14N2O7) and amino acids (arginine, leucine, serine, lysine, alanine and glutamic acid) on the activity of cell envelope proteinases (CEPs), specific activity, protein content, OD600 value and pH in MRS broth fermented by Lactobacillus plantarum LP69. Results. The optimum concentration of inulin (0.7%), isomaltooligosaccharide (0.5%), Na2HPO4 (0.4%), CH3COONa (0.4%), leucine (20 mg/L), serine (20 mg/L) for L. plantarum LP69 was estimated with the activity of CEP in the range 17.36-21.47 U/mL, protein content in the range 19.18-22.53 mg/mL, specific activity in the range 0.77-1.12 U/mg. Conclusion. Inulin, isomaltooligosaccharide, Na2HPO4, CH3COONa, leucine and serine are superior to other selected substances, and have a significant influence on the CEP activity and specific activity of L. plantarum LP69. This would provide a reference for further optimization of CEP-producing media of L. plantarum LP69.