Characterization Of Alginate Lyase From Marine Bacterial (Vibrio Sp.H) And Study On The Product Of Alginate Degraded By Enzyme

Extracellular alginate lyase secreted by Alginate degradation strain, which was isolated from laminaria japonica from the natural decay of Weihai. Using sodium alginate as the singulare carbon source,a marine bacteria Vibrio sp.H was got through training and screening.The Vibrio sp.H is Gram-negative,Rod-shaped.The strains is facultative anaerobic and the optimumis condition for its growth is 25℃,pH 6.5 and concentration of NaCl is 4%.It is Oxidase-positive,which is Sensitive to inhibitor of Vibrio,Non-luminous and do not produce pigment.The study showed that the Vibrio sp.H is blong to Vibrionaceae Vibrio.The research on the nature of alginate lyase showed that its molecular mass was 56.2 KD.and Enzyme activity is 123.23U/mg.The enzyme bad an optional temperature of 25℃for its activity,and was most active at pH 6.5.The Km was about 76.35g/L.From effects of metal ions on enzyme activity, The EDTA and Zn²⁺ shows enhancement of(M)n and(G)n enzyme activity.The Ba²⁺ shows inhibition of(M)n and(G)n enzyme activity.The best concentration of Alginate was 3%and Poly(G) of(M)n decreased very well at the same time.The enzymolysis of Vibrio sp.H on the Alginate was observed.With the best concentration of the Alginate we can get Poly(M) and Poly(G).Then we have further reacherON the Nature of Poly(M)and Poly(G).The follow is the result.The appearance of the nature of Poly(M) is white solid.Its aqueous solution is colorless and pH is 6.96.Poly(G) is pale yellow solid.Its aqueous solution is yellowish and pH is 7.98.Visible absorption appeared at 220～250nm and 230～250nm and there is no absorption in the foreseeable band.Carbonization temperature of Poly(M) and Poly(G) is between 226℃and 285℃.Optical activity that is levorotation is between -0.5 and -0.65.From saccharous electrophoresis analysis of the oligosaccharide,the degree of degradation of the alginate lyase on Poly(M) is greater than Poly(G). Weight-average molar mass of Poly(M) is 601 and molecular weight of Poly(G) is 3177 by GPC.Poly(M) can get three monosaccharides,Poly(G) can get sixteen polysaccharides.From IR,we alse know that at 940nm the absorbency of Poly(G) is greater than Poly(M).