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Lipase is a special kind of an ester bond hydrolase, lipolysis glycerolipid and fatty acid, is widely found in animals, plants and microorganisms, can also be obtained by chemical synthesis. Plants and animals as a source of these resources by the climate, soil conditions, lipase addition, the plant and animal species separation and purification is more complex, and the complex process of chemical synthesis, and the higher cost, so most of the enzymes are microbial produced by fermentation. Currently, the production of lipase microorganisms including Aspergillus niger, Geotrichum candidum, Pseudomonas, Mucor, Rhizopus, Candida lipase produced are widely used in industry, such as washing industry, food industry, chemical industry , leather, paper, etc., in recent years, the lipase in the pharmaceutical industry have also been more and more attention. Therefore, there is a huge potential economic value obtained in the development of the pharmaceutical industry, the strains of high-yield lipase. This study is screened from the environment of the fatty four lipase production strain, strains were named as 7, strain, strain 6 strain 5, these four strains their respective lipase activity was measured by titration were 3.00U/mL, 1.70U/mL, 1.70U/mL, 4.00U/mL. Strains investigated strains culture conditions, results showed 7 at a temperature of 25 ° C, pH value of 7.0 when the conditions, the incubation time as for 72h produced by the enzyme highest lipase activity. 16SrRNA sequence analysis of the molecular biology of the strains, the strain was identified as Pseudomonas spp consolidated its morphological characteristics, named as strain 7. The crude product of the strain produced by the lipase in the separation and purification of lipase initially identified its isoelectric point, and the culture liquid salting range results show that the lipase isoelectric point of about 6.0, ammonium sulfate saturation of 40% - 50% for the best range of salting. Culture supernatant after grading salting out, desalting, DEAE-Sepharose Fast Flow chromatography, freeze-drying, the Sephadex G-75 chromatography separation and purification methods, SDS-PAGE test results show that the molecular weight of the lipase is about 31ku. The study also looked at the optimum conditions for lipase its stability, results showed: the the lipase optimum pH of about 9.0, and the optimum temperature of 40 ° C. The lipase has a wide pH and temperature stability range, at pH 8.0, the temperature is more stable under the conditions of 30 ~ 50 ℃. Metal ion in a final concentration of 1 mmol / L Li, Mg2, Ba2 significant role in promoting the activity of lipase activity, Tween 80 and Triton-100 on the enzyme activity to serve as a catalyst for EDTA on the enzyme activity exists significantly inhibited; ethyl acetate presence of inhibitory effect on the enzyme activity, but the effect is weak, and the performance of certain alcohol resistance.
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