Study On Sryeening Bacteria Of Flax Degumming,Identifying And Knowing About Microbiology Diversity

Flax is a very important textile raw material and is popular with people. There are three mainly methods of flax degumming, physical, chemical and biological. At present biological flax degumming is the main using and investigative method. biological flax degumming includes adding bacterium and adding enzyme. In this thesis It has investigated correlation parameter and factors of flax degumming in lab conditions analyse the flax degumming factors with determining enzyme activity. they have filtered some bacteria of efficient flax degumming and made the identification. they have investigatived the influence factors of degumming bacteria's pectinase activity. they also investigatived the microorganism diversity at different conditions of flax degumming using DGGE method. The main results are as follows:1. At the process of flax degumming, The amount of alive bacterium goes up at the prophase and falls at the anaphase. Pectinase, cellulose and xylanase are very important and have effects on flax degumming, The content of pectinse is higher than two others. The quantity of nitrogen and reducing sugar are rapidly increasing at the prophase of flax degumming. In the falx degumming process microorganism utilize carbon. The content of reducing sugar decrease and the content of nitrogen increase among the fluctuation. pH has a sharp deline in the prophase and becomes stabilization in the anaphase. COD has a sharp increase in the prophase and has a slowness increase in the anaphase.Among the influence factor, wo choose temperature, ratio of flax stem to water,pH and degumming additive to investigate. The optimum erternal retting conditions were as follows:water temperature 35℃, ratio of flax stem to watel:20 and pH 6 or 8. The activity of pectinse is higher. Adding urea into rettng water has higher activity of pectinse than adding others and adding none. The activity of xylanase is higher with adding ammonium nitrate then others .2. There are abundant microorganism in the soil. When flax were retting, we added diffent type of soil into the retting water and more then 50 bacteria were screened from them. Four bacteria with higher flax retting effect were chose from them. In order to identify their category we determined their gene sequence. They were preliminarily identified and GJ-87-1, GJ-87-2,GJ-87-3 were named as Bacillus. GJ-86-6 were named as Paenibacillus massiliensis. We added these four bacteria into flax stem respectively and added water to ret, then determined interrelated enzyme. The result were that when we added bacteria we fond the activity of pectinse and xylanase observably increased and activity of cellulose was low in retting water. They conformed to the require of degumming bacteria. We also determined others interrelated parameter reducing sugar,nitrogen,pH and ratio of flax stem degumming. The result were as follows: when we added bacteria into retting water the reducing sugar has no remarkable change, the content of nitrogen has a sharp increase, the ratio of degummed flax stem increased and pH showed alkalescence.3. We investigated the influencing factors to the activity of pectinse about the four bacteria temperature, pH, carbon, nitrogen and metal ion. The pectinse's activity of bacteria was higher at 35℃than others; The pectinse's activity of bacteria was comparatively higher when the substrat was at acid condition; To carbon origin, the activity of pectinse was higher when we added bran and pulse flour than others ; Adding ammonia sulfate, the activity of pectinse was higher than adding others; Different metal ion has different effect to the activity of pectinse about the four bacteria.4. We extracted DNA of bacteria from the retting water at different time and use PCR-DGGE method to investigated dynamic change of microorganism diversity in the retting water. The result was that microorganism diversity of the retting water was higher at prophase than at other time(at about 24 hours), then the microorganism diversity was steady until flax retting finished. When we used four methods to deal with the flax degumming, the resulst of microorganism diversity about the retted water were very different. Microorganism diversity is higherthan others when we added oxygen to the retting water . when we added urea into the retting water the microorganism diversity decreased. There were dominant population when we added GJ-86-6 to the retting water.