Isolation and characterization of lactic acid bacteria from sugarcane waste

Abstract

Aim: Researchers are focusing more on the isolation of new probiotic bacteria to increase varieties for the growing market demand. This study aimed to isolate lactic acid bacteria (LAB) strains from sugarcane waste materials and evaluate its characteristic. Methodology and results: In the present study, two strains of LAB (Isolate A and B) were isolated from sugarcane waste and investigated in vitro for their characteristics as potential probiotics. These isolates were evaluated on their characteristics based on four biochemical tests (acid tolerance, bile tolerance, microbial adhesion, and phenol resistance), with the commercial strain Lactobacillus isolated from Yakult ® served as a positive control. Both isolated strains (>8 log10 CFU/mL) displayed higher survivability than control (>6 log10 CFU/mL) in simulated gastrointestinal conditions at pH 2.0 and pH 6.9 after 24 h. Furthermore, both isolated LABs were resistant to inhibitory substances which are 0.05-0.3% bile and 0.4% phenol. For bile tolerance, isolate A (OD 6.83) had a higher absorbance at 0.3% bile concentration as compared to isolate B (OD 2.20). However, isolate B (7.49 log10 CFU/mL) showed higher resistance towards 0.4% phenol than isolate A (7.11 log10 CFU/mL) after 24 h. Both isolate A and isolate B displayed low cell surface hydrophobicity, strong electron donor, and basic characteristic. Conclusion, significance and impact of study: Both isolates were able to survive under gastrointestinal stress conditions, implying their potential as probiotics. This study demonstrated that valuable products such as probiotic strain could be isolated from sugarcane wastes to use in food production or medical treatment.