Screening and Identification of Alginate Lyase-producing Strains and Optimization of Its Enzyme-production Conditions

Using sodium alginate as the sole carbon source medium, the microorganisms in Sargassum collected from Weizhou Island, Guangxi, were screened and isolated. The relative enzyme activity was determined by 3,5-Dinitrosalicylic acid (DNS) method, and the high-yield strain, marked M0101, was obtained. According to the morphological, physiological and biochemical characteristics and 16S rDNA sequence analysis, the target strain was identified to belong to the genus of Vibrio, named as Vibrio gangliei M0101. The prioritization scheme of enzyme production of M0101 was confirmed by a single factor test: Alginate 50 g/L, (NH₄)₂SO₄ 2 g/L, K₂HPO₄ 1 g/L, NaCl 100 g/L, MgSO₄·7H₂O 1 g/L, FeSO₄·7H₂O 0.01 g/L, 30 ℃, 200 r/min, initial pH9.0; and the maximum enzyme activity of strain M0101 reached 221.90 U/mL after optimation. It was 6.11 times higher than before(36.32 U/mL). Its efficiently hydrolysis of high concentration alginate and high salt tolerance, which has potential for large-scale preparation of alginate lyase.