Screening of alginate lyase-producing microorganisms and optimization of fermentation conditions in disc abalone
LI Yun-tao1, WANG Li-ping1,2, ZHANG Meng1, ZHANG Yu1
1. Shanghai Engineering Research Center of Aquatic-Product Processing & Preservation, College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China; 2. Engineering Research Center of Food Thermal-processing Technology, College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China
Abstract: A bacterial strain producing alginate lyase named SS-1 was isolated from intestine of disc abalone Haliotisdiscushannai using sodium alginate as the sole carbon source on agar medium by transparent circle method, and initially identified as Vibrio sp. by morphological observation and 16S rRNA gene sequence analysis in order to screen biodegradable alginate lyase microbial strain. The best fermentation of SS-1 producng the aximal activity of alginate enzyme was observed under conditions of 30 ℃, initial pH 7.2 with activity of about 38.6 U/mL in 28 h. The optimization by a response surface methodology revealed that the optimal fermentation medium of SS-1 was comprised of maltose 11.86 g/L, yeast extract 16.72 g/L, K2HPO4 1.36 g/L, MgSO4·7H2O 1.5 g/L, FeSO4·7H2O 0.1 g/L, and NaCl 6.75 g/L. The supernatant of strain SS-1 had activity of 191.8 U/mL in optimized medium, 4.97 times higher compared with the basic medium, indicating that strain SS-1 is of a potential strain for alginate-derived oligosaccharide (ADO) industrial fermentation.
2017, Vol. 32 
