Separation Of A Alkali Protease Producing Strain And Its Application

In this paper, a bacterial strain was employed to use organic nutrients in the water after extracting Camellia oil with aqueous enzymatic extraction method to produce alkaline protease. The alkaline protease then was utilized with tea saponin together to wash the dirty cloth. Microbial screening and identification, mutation breeding, and fermentation conditions were studied with the optimization of enzyme activity and detergency, in order to select a good alkaline protease producing strain and better culture conditions. The main conclusions are as follows:A strain of Bacillus was isolated from the soil of an oil mill in Zheqiao Town, Leiyang, Hunan Province. It was capable of producing alkaline protease by fermenting the soaking fluid of camellia cake. The determination of the enzyme activity indicated that its enzyme activity value was 150U/mL. To determine its dirt-removing power by making a detergent with adding this strain, the result showed that the stain removal index of this detergent was 18, which was 2 times as much as that of the detergents without the strain。The strain was identified as Bacillus Sp.The UV mutagenesis experiments on the strain were studied. The optimum conditions were as follows:10"5-fold dilution,0.1 mL Bacterium fluid, and 3 minutes of ultraviolet exposure. The determination of the enzyme activity indicated that its enzyme activity value was 290U/mL,2-time as much as before. To determine its dirt-removing power with a detergent test, the result showed that the stain removal index of detergent was 19。The strain was named STPZ-503。Factorial experiment design was used to study the effect of different carbon, nitrogen sources, metal ions, and amount of the water after extracting oil on enzyme activity value。The study incideated that the soluble starch, sugar, yeast extract, camellia cake and Mn2+ are best for enzyme production And the best cultivation condition was as follows:36℃,250rpm,8.5pH, and inoculation amount 5%(v/v), The determination of the enzyme activity was up to 310U/mL。Response surface methodology was used in the design of experiments and in the analysis of results. This procedure limited the number of actual experiments performed while allowing for possible interactions between the components. The optimum values for the tested variables for the maximum alkaline protease production were sugar 1.00 (g/L), yeast extract 1.55 (g/L), and the soaking fluid 81.0%(v/v). The maximum alkaline protease production was 540.68U/mL,2 times as much as before; The maximum removal index of detergent was 20.21。...