Production of Dextran from Locally Lactobacillus Spp. Isolates

摘要

Background:Dextran is a commercially available bacterial exopolysaccharide (EPS) with several industrialapplications in the food industry and in the biomedical industry as an adjuvant, emulsifier, carrier, andstabilizer. The production of dextran at the industrial level occurs through the fermentation of a sucrose-richmedium. Research to optimize dextran production has found that the yield of dextran varies depending thespecific conditions for production. The aim of this study was to produce dextran and establish the optimalconditions for dextran biosynthesis from different Lactobacillus species isolated from healthy vaginal andinfant stool samples.Methods:Lactobacillus spp. were isolated and identified from vaginal and infant stool samples via the VITEK2 system. The presence of dextran biosynthesis from the different Lactobacillus spp. isolates was determinedby a screening test for mucoid colonies and confirmed via the ethanol precipitation method. To optimize forthe maximum yield of dextran, the effects of various parameters such as temperature, incubation time, pH,inoculum size, aeration, and sucrose concentration were examined.Results:All Lactobacillus spp. isolates were able to produce dextran. The optimal conditions for dextran productionwas at 24 hours of incubation at 30 °C with 15% sucrose, 4% inoculation size at pH 7.0 in aerobic conditions. Thisyielded a dextran dry weight of 580 mg/100 mL.Conclusions: Dextran production from Lactobacillus species isolates vagina and infant stool had the ability toproduce dextran.