Identification Of Alginate Lyases Producing Microbe And Immobilization Of Its Alginate Lyases

Brown algae is the common marine plant in coastal regions, its main composition are polysaccharides. Recently studies showed that alginate oligosaccharides, the degradation products of alginate, have significant effect on tumor treatment and enhanceing immunity. Alginate oligosaccharides have been widely used in pharmaceutical, feed, functional food, and other industries. In this paper a strain producing alginate lyase was identified and further researches on alginate lyase immobilization were also studied. It will provide a theoretical basis for the utilization of alginate lyase industry. The main results were as follows:(1) An alginate lyase producing strain was selected and the physiological and biochemical characteristics were also studied and then identified by 16 s rDNA sequences as Pseudoalteromonas genus, and named as Pseudoalteromonas sp.L1.(2) The immobilization of alginate lyase was studied by the method of diatomite adsorption, and the effects of carrier dosage, immobilization time, temperature and the pH value on immobilized alginate lyase were investigated. Orthogonal test suggested that the optimum condition was: the diatomite dosage was 0.15 g for 1g alginate lyase, immobilized at 35℃for 2h in pH7. The immobilization rate was 92.05%, and the activity could reach 1.39 U/g. Compared with free alginate lyase, the thermal and acid-basic stabilities of immobilized alginate lyase were both obvious increased. After immobilized alginate lyase was recycle used for 7 times, the activity in immobilized alginate lyase remained in 68.27% of its initial activity. The results showed that the diatomite adsorption method in immobilized alginate lyase has excellent characteristics for industrial production.