Exopolysaccharide production from isolated Enterobacter sp. strain ACD2 from the northwest of Saudi Arabia

Substantial interest has emerged on the use of marine microorganisms as producers of important macromolecules such as exopolysaccharides (EPSs), to apply them in areas including the food, pharmaceutical, and cosmetic industries, as well as other important sectors. In this study, thirty seven marine bacterial isolates were isolated from Haqel Beach in Tabuk region, Saudi Arabia. We found that only nine isolates have the ability to produce extracellular polysaccharides in medium. We selected the best producer and characterized it morphologically, biochemically, and molecularly using 16S rRNA analysis, revealing it to be Enterobacter sp. We also optimized the culture fermentation conditions to obtain the highest EPS yield. Our results showed that the optimal medium conditions were as follows: 15% sucrose, 0.5% peptone, presence of all fermentation medium salts, pH 7.5-8.0, incubation temperature 37 degrees C, and shaking at 150 rpm for 72 h, which conferred the highest EPS yield of 8.6 g/l.

Automated summary

This study isolated thirty-seven marine bacterial isolates from Haqel Beach in Tabuk, Saudi Arabia, with only nine of them capable of producing extracellular polysaccharides. The best producer was identified as an Enterobacter species through morphological, biochemical, and molecular characterization. By optimizing culture fermentation conditions, a high EPS yield of 8.6 g/l was achieved, with optimal medium compositions and incubation parameters established.