Study the optimum conditions for biosurfactant and bacteriocin production from Lactobacillus plantarum isolated from different sources

The goal of current research is to study the optimal conditions for the biosurfactant (lipid) and bacteriocin production from local isolate Lactobacillus sp. A total of 120 Lactobacillus sp. isolates were obtained from several sources, recognized according to biochemical tests, and screened utilizing primary and secondary screen processes for bacteriocin and lipid production. According to the observed results, the isolate Lactobacillus sp. ZMJ20 obtained from the clinical sample of healthy Iraqi females revealed to the highest lipids emulsifying activity E24% (60%) and decrease in surface tension to 29.2 mN/m and higher bacteriocin inhibitory impact against pathogenic isolate Candida albicans with a diameter of (22 mm). Therefore, the isolate Lactobacillus sp. ZMJ20 was selected for identification and optimization studies. The isolate was recognized as Lactobacillus plantarum by VITEK 2 system and ensured via molecular identification by PCR technique. Modified MRS medium was used in the fermentation processes for bacteriocin and lipid production by of L. plantarum. The findings of optimum conditions showed that fructose was the best source of carbon and energy instead of dextrose (glucose) and the best nitrogenous sources were meat and yeast extract at ratio (1: 1) with a percentage of (2.5%) instead of peptone, meat, and yeast extract together. The ideal pH was (6.5), the optimum temperature was (37°C) and the best incubation period for bacteriocin and biosurfactant (lipid) production was after 48 and 72 hours respectively. All the production processes are adopted under anaerobic conditions.