A novel exopolysaccharide from deep-sea bacterium Zunongwangia profunda SM-A87: low-cost fermentation, moisture retention, and antioxidant activities.

Research paper by Mei-Ling ML Sun, Sheng-Bo SB Liu, Li-Ping LP Qiao, Xiu-Lan XL Chen, Xiuhua X Pang, Mei M Shi, Xi-Ying XY Zhang, Qi-Long QL Qin, Bai-Cheng BC Zhou, Yu-Zhong YZ Zhang, Bin-Bin BB Xie

Indexed on: 30 May '14Published on: 30 May '14Published in: Applied Microbiology and Biotechnology


Many marine microorganisms can secrete exopolysaccharides (EPSs) which have important applications in biotechnology. We have purified a novel EPS from deep-sea bacterium Zunongwangia profunda SM-A87, identified its glycosyl composition and linkage, and optimized its production to 8.9 g/l in previous studies. To reduce the fermentation cost, an economical fermentation medium containing 60.9 % whey, 10 g/l soybean meal, and 2.9 % NaCl was developed. The EPS yield of batch fermentation in this medium reached 12.1 ± 0.3 g/l. Fed-batch fermentation was conducted and led to an EPS yield of 17.2 ± 0.4 g/l, which represents the highest EPS yield ever reported for a marine bacterium. The EPS was extracted and it displayed good rheological properties, moisture-retention ability, and antioxidant activity. Particularly, its moisture-retention ability is superior to that of other marine bacterial EPSs reported to date. SM-A87 EPS also showed high antioxidant activity. These results suggest that SM-A87 EPS has promising potentials in biotechnology.

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