Screening And Identification Of High Efficiency Ramie Non-fiber Degradation Strains And The Research On Degumming Process

Ramie dubbed as "The Chinese herb", and the ramie fiber was known as "The king of fiber", sold around the word as high-grade textile materials. It is the important natural fiber resources of our country. However, original ramie can’t be directly used in textile, because it contains vast non-fiber gelatine. So, firstly, we had to take steps to make the ramie degumming. The traditional natural degumming methods need so long time, and low efficiency; The chemical methods, widely used at present, consumed energy and made serious pollution. The worstly is in this way it damnify the ramie fiber, and hard to get the high quality ramie spinning fiber. In recent years, biological degumming method has been studied widely.We used the ramie non-fiber gelatine as target, screening high efficiency degradation strains from nature. And used to extract the spinning ramie fiber. Through the experiment obtained the following results:1. Screening and identification of high efficiency ramie non-fiber degradation strains.We,on ourselvesly, found a screening model,and obtained 13 high efficiency degradation strains, and carry on the enzyme production performance measurements.The enzyme activity of strains, and combined with the final degumming result, showed that strains B6 and M7 are high-yielding strains of pectinase and xylanase, and the cellulose activity is lower. The property of degumming was stable afer domestication. They would be used as degumming strains in the later experiments.According to morphologic, physiologic-biochemic and molecular biologic experiments, identified B6 strain as Bacillus cereus, and strain M7 kwon as Penicillium tardum. Thom.2. Optimization enzymatic production conditions and the degumming process of the selected strains.Use the single factor rotation method and delition method optimized the enzymatic production conditions of the two strains, found that the two strains can breed the ramie no-fiber-gelatine as nutrition. In the degumming process,the strain B6 only need 5%o of MgS04·7H2O as growing factor. And for strain M7 only need to add 0.7‰of K2HPO4 to the fermentation broth to adjust the pH value.Based on the single factors analysis and determination, we studied the degumming effects with the mathematical model of quadratic rotation-orthogonal combination design. Finally, we obtained the best experiment scheme, as follows: Strain B6:Degumming time50.2h, Degumming temperature32℃, pH 6.4, inoculation amount7.68%, ratio of fiber/water 1:25 Strain M7:Degumming time59.2h, Degumming temperature28℃, pH 7.0, inoculation amount 13.2%, ratio of fiber/water 1:33Through the experiment, we got the final residual gum contents were 10.24% and 10.99% respectively. And the better thing is that they have the similar technological conditions, and it provide the possibility of the two strains unite degumming.2. Union strains degumming and simulated experiment in natureAccording to the growth characteristic, enzymatic production activity and the required degum process conditionsof the two strains, design a union strains degumming experiment in the stationary wave bottle fermentation:First, use the mold M7 to degum,30 hours later, inoculate the bacteria B6. Under this fermentation degumming experiment scheme, we got a lower residual gum content. Based on the above conditions, we simulated a small industrialization retting flax in nature. This experiment laid a foundation for the union strains directly using in ramie degumming industrial.