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Objective: amylase is an important industrial enzymes, has been widely used in food, washing, pharmaceutical and other industries. Due to low temperature amylase with high catalytic activity at low temperatures and the heat-sensitive characteristics, so that it has a broad application prospects in the field of bio-engineering and energy conservation. The low temperature amylase general is generated by the low-temperature microbes, thus screened for the production of low-temperature amylase strains are the primary source of low temperature amylase based. Permafrost is referred to as low-temperature microbial resource treasure house, isolated from the Tianshan permafrost, purification of low-temperature microbes for low-temperature the enzyme strains of significance screening out high-quality, high-dynamic production. Methods: In this study, the unique geographical environment in Xinjiang, isolated from Tianshan Glacier permafrost, and purified strains produced low-temperature amylase, to solve the problem of low temperature amylase sources. Fermentation conditions for the production of low-temperature amylase enzymatic properties and strains of laboratory strains screened studies to further understand the nature of the low-temperature amylase, lay a theoretical and practical foundation for basic research and industrial application of the low-temperature amylase. Conclusion: ① through conventional dilution plate method, from the Tianshan Glacier ice containing frozen soil screening produced in low-temperature-amylase strains three, respectively, the number L10-1, M12-1, X2. Phylogenetic tree of strains of physiological and biochemical experiments and enzyme production strains showed that: strain M12-1, X2 Paenibacillus polymyxa closest genetic relatives, 99% similarity; strains L10-1 and Hymenobacter.sp closest genetic relatives, similarity only 96%, indicating that the strain L10-1 may Hymenobacter bacteria of the genus, belonging to the genus temporarily, pending subsequent further identification. (2) By comparing the three strains, the optimum growth temperature, enzyme optimum temperature and strain average ratio of the size of the diameter transparent circle, to determine L10-1 enzyme production target strains, their relative activity reached 28.2U/mL of. Bacteria optimum growth temperature range of 18 ~ 24 ℃, case areas psychrotrophs; production amylase optimum temperature of 35 ° C isozymes optimum temperature around 25-30 ℃ (temperature amylase optimum temperature of 60-65 ° C) ③ The strains producing the enzymatic properties: studies have shown that the strain L10-1 amylase extracellular enzymes, the optimum temperature of 35 ° C; optimal pH value 6.0; poor thermal stability of the enzyme were maintained 30 ° C and 40 ℃ for 30min 60% and 20% of the activity, the enzyme activity is almost undetectable after 20min incubation at 60 ℃; Ca2, MG2, K of Mn2, Na this enzyme have different degrees of activation, Co2, Cu2, Zn2 significantly inhibited the enzyme; phenyl methyl sulfonyl fluoride (PMSF), ethylenediamine tetraacetic acid (EDTA), dodecane yl sulfate (SDS) significantly inhibited the enzyme, indicating that the enzyme is a typical metal activating enzyme, while the active centers may exist a group of serine (serine). ④ laboratory strains L10-1 enzyme production optimum fermentation conditions: 1% sucrose (carbon source), 1.5% casein hydrolyzate (nitrogen source), loading volume of 500 ml Erlenmeyer flask medium 250ml, shaking speed 200r / min and cultured 36h after the enzyme by 15.23U/mL to 29.13U/mL. The above conclusion is more similar to the research at home and abroad, that the enzyme has some potential for development and application.
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