Abstract
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 °C, and shaking at 150 rpm for 72 h, which conferred the highest EPS yield of 8.6 g/l.