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Chitosan is found so far only trona polysaccharide, with a wide range of applications in the field of medical, textile, food, health, printing and dyeing, cosmetics, wastewater treatment, as well as a huge product development and marketing capabilities. Chitin deacetylase (chitin deacetylase, EC3.5.1.41) is the production of enzymes, catalytic chitin into chitosan deacetylated chitin into a shell by catalytic N-acetylamino-D-glucose amine polysaccharides, mainly binding bacteria Gang of fungi. Use it instead of the now widely used in concentrated alkali pyrolysis production of chitosan, which can solve the environmental pollution problems currently chitosan production, and can produce high-quality chitosan products. The papers from the natural environment in screening the to the chitin deacetylase yield bacteria Z7. And optimization of fermentation conditions of enzyme production and enzymatic properties of this strain, has laid a good foundation for later chitin deacetylase industrial production. The results are as follows: (1) Chitin deacetylase Screening and identification of high-yielding strains. In this study, nitro-N-acetanilide as chromogenic reagent from the flood, in the ruins of the soil of the beach as well as shrimp and crab processing plant screening to the production of chitin deacetylase strains 36, according to the differences in the ability of the chromogenic screening to production Chitin off nine the acetyltransferase ability strains. By further fermentation rescreening, a chitin deacetylase producing strain Z7, Central South University of Forestry Science and Technology Culture Collection number F14 CSUFT. Of Bergey strain identification manual and the 16s rDNA sequence analysis identified strains Z7 Bacillus amyloliquefaciens (Bacillusamyloliquefaciens). (2) the chitin deacetylase yield optimization of fermentation conditions. The use of single-factor method strain Z7 shake flask batch fermentation conditions. Strains the Z7 producing chitin deacetylase optimal culture conditions: age 10h, culture temperature of 37 ° C, pH 6.0, shaking speed 160r/min, with volume of 20%, incubation time 28h. Plackett-Burman experiment and response surface experimental combination of methods to get the best strains for enzyme production fermentation medium formulation: chitin 10g / L starch 25g / L, yeast extract, 10g / L, magnesium sulfate 0.25g / L, potassium dihydrogen phosphate 0.3 g / L, NaCl 5 g / L, the activity level has reached this condition 27.48U/mL. In this paper, strains Z7 optimum fermentation medium, enzyme activity and the relationship of the growth curve, determine the strains the Z7 fermented type growth associated. (3) the basic properties of chitin off high-yielding strains of enzymatic deacetylase. Deacetylase enzymatic properties of chitin produced by strains Z7 showed that: the enzyme optimum temperature of 40 ° C, the optimum pH value of 6.5, 1mmol / L concentration, Mg2, K, Ca2 and Fe2 ions on activation, which most Mg2 activation pb2 Cu2 and Mn2 inhibit the enzyme, which Mn2 strongly inhibited.
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