Functional and technological properties of exopolysaccharide producing autochthonous Lactobacillus plantarum strain AAS3 from dry fish based fermented food

Abstract

The present study was aimed to evaluate the disparate functional and technological properties of exopolysaccharide (EPS) producing potent Lactobacillus sp. Initially, 10 autochthonous probiotic bacteria were isolated from Hentak and screened for EPS production. Among them, Lactobacillus plantarum strain AAS3 was identified as maximum producer of EPS (450.5 ± 5.8 mg/L) and assessed further for evaluating functional and technological attributes using standard methodologies. Strain AAS3 maintained its viability towards simulated gastric juice (pH 2.0) with total cell counts of 2.4 ± 0.06 log cfu/mL. The isolate showed pronounced β-galactosidase activity (18.3 ± 0.6 U/mL), bile salt hydrolase production (3.32 ± 0.5 U/mL), and cholesterol reducing property (41.6 ± 0.8%). Propitious antioxidant traits of strain AAS3 were observed in terms of scavenging hydroxyl radicals. The isolate sustained high concentrations of NaCl, fermented distinctive carbohydrates, and produced important hydrolytic enzymes. Further, strain AAS3 displayed promising autolytic property (56.4 ± 1.2%), catalase activity (22.34 ± 0.3 AU), and nitrite production (28.2 ± 0.8 mM nitrite/mg dry weight). Most importantly, the isolate showed not only negative results towards in vitro haemolytic, DNase, and gelatinase tests but also sensitivity to conventional antibiotics tested. In conclusion, pronounced EPS production, exemplary functional and technological traits, and safety aspects signify suitability of L. plantarum strain AAS3 in food processing industries as quintessential adjunct/starter culture.