Isolation of Biotechnologically Important Exopolysaccharide Producing Bacteria from Different Environments

Abstract

Exopolysaccharides (EPSs) are carbohydrate polymers that occur naturally and are excreted by some microorganisms. The microbial EPS has a number of biotechnological uses in paints, textiles, cosmetics, medicine, etc. Interest in searching for novel EPS has increased due to the broad range of applications of EPS. Therefore, this study focused on isolating, screening, and identifying the most potent EPS-producing bacteria from different habitats. A total of 10 different samples were collected from in and around Dhaka University Campus. After initial screening, 88 distinct bacterial colonies were considered to be producing exopolysaccharides on the basis of thick mucoid colonies on nutrient agar medium. The findings showed that EPS-producing bacteria are widely dispersed throughout various habitats. Out of 88 isolates, 20 better isolates were finally selected for extensive study. The isolated Gram-positive bacteria belonged to the genera Micrococcus, Streptococcus, and Bacillus. While Gram-negative bacteria were identified as Proteus myxofaciens, Chryseobacterium sp., Klebsiella pneumoniae subsp. Ozaenae, Edwardsiellaictaluri and Acinetobacter sp. The EPS production ranged between 0.55 ± 0.04 and 2.21 ± 0.06 g/l. Bacillus subtilis (P11) was identified as the most promising isolate for EPS production, yielding the highest amount at 2.21 ± 0.06 g/l. The current study's findings showed that these local isolates could produce important exopolysaccharides and might be used in various biotechnological aspects.

Plant Tissue Cult. & Biotech. 35(2): 247-255, 2025 (December)