Effect of lactic acid produced by lactic acid bacteria on prodigiosin production from Streptomyces coelicolor

Often isolated from soil-dwelling microbes such as Serratia marcescens and Streptomyces coelicolor, red-pigmented prodigiosin and its derivatives have been characterized as natural bioactive compounds which possess a broad range of cytotoxic activity against various cancer cell lines as well as other biology activities. The raising need to enhance the production of this secondary metabolite due to its wide applications in both industrial and therapeutic field has gained attention from researchers over decades. Several approaches were carried out ranging from improving nutrient sources to metabolic engineering of S.coelicolor or co-cultivation with other bacteria. Recently, studies reported cell-free supernatant from lactic acid bacteria (LAB) intensively stimulated the pigment production from Streptomyces colelicor, however the reason for this enhancement was still unknown. In this study, we further investigated on the effect of lactic acid, a bioactive compound extracted from cell-free supernatants of LAB on prodigiosin production from Streptomyces coelicolor. The resulted data with 2 different strains of lactic acid bacteria (Leuconostoc mesenteroides and Lactobacillus plantarum) revealed treatment with lactic acid isolated from LAB exhibited an inhibition effect on prodigiosin yield in both intracellular and extracellular extraction.