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Since ancient times, the silk is known as the \It is the unique structure and silk amino acid composition, silk fibers exhibit elegant luster, comfortable feel and good moisture absorption, desorption and insulation, it has been very popular as textile materials. Silk fibroin by 75% to 80%, and 20% to 25% sericin. Production process silk by unglued processing to remove most of the sericin highlights the unique luster and supple. The silk degumming the method according to the nature of the sericin, grease, wax and other debris, unglued when using the different treatment agent, silk degumming into chemical degumming and enzymatic degumming (microbial retting) categories. Silk degumming chemical method, the main drawback of such methods is uneven unglued, degreasing effect, loss of strength of the silk fiber, water consumption, energy consumption and pollution of the environment, is a class of high consumption of resources process. Enzymatic degumming process at room temperature the degumming process fibroin damage is very small, so that the excellent quality of the silk can be adequately protected. Enzyme with less, and the reaction after the release of the enzyme can continue reaction of catalytic another; biodegradable wastewater treatment, therefore, reduce pollution and save energy. Enzyme degummed silk fiber surface is more smooth, transparent, silk Ming stronger sense. It can be said that the enzymatic degumming process is a very typical softness of silk, polishing, and improve the processing of wearability. The enzymatic degumming compensate for the lack of silk chemical degumming law to make a qualitative leap in the raw silk quality. The purpose of this study is to obtain the silk degumming enzyme high yield bacteria strains producing the enzyme activity unit and silk degumming rate indicators from Sichang surrounding soil separation, screening to get one pair of silk with a significant the degumming ability Bacillus subtilis (Bacillus sp. ), numbered scw2-1. On this basis, for the identification of the strains, the study of the optimization of the fermentation conditions and the strain producing silk degumming rates of the active substance, such as testing. The main results are as follows: 1. Silk degumming enzyme producing strains separation, screening and degumming experiments 7 degumming enzyme production capacity strains isolated from mulberry fields and silk factory in the surrounding soil, respectively, named scw1-1, scw1-2 scw1-3, scw2-1, sy4-2, sy6-1 SY6-2 the on which scw2-1, SY6-1 and sy6-2 three strains has obvious advantages compared with other several strains producing the active material capacity. Silk degumming scw2-1, sy6-1 and sy6-2 three strains of testing, results showed that the three strains produced the active substance the silk degumming role, especially scw2-1 strains producing active substances degumming the most significant. produced in fermentation 3d the active substances unglued strongest, with the prolongation of degumming time, degumming is proportional to the rate of growth in the after degumming 4d to the Dasi glue completely Tuojin-scw2-1 strains. 2.scw2-1 strains identified scw2-1 strains classification and identification of morphological, physiological, biochemical, and molecular biology. Morphological, physiological and biochemical characteristics of test results show that the, scw2-1 strain of the Gram-positive rod-shaped bacterium, Bacillus, can not the movement of the bacteria; beef extract peptone solid medium for 24h, cell growth good; 16S rDNA Sequence analysis showed that the sequence of Bacillus thuringiensis (Bacillus thuringiensis) FJ462697.1 sequence homology of 16S rDNA as high as 99%. The integrated indicators identified results, identification of the strains belonging to Bacillus genus, named for the optimization of fermentation conditions of Bacillu sp.scw2-1. 3.scw2-1 strains producing degumming enzyme of scw2-1 Optimization of the fermentation conditions made get medium best carbon source for soluble starch, nitrogen sources for soybean powder, metal ions K , and the optimum temperature of 37 ° C, initial pH of 5.0, fermentation time 72h . Get the best of each component of the fermentation medium by orthogonal test: 3% of the soluble starch, soy flour, 3% 4 1% the KH 2 PO .
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