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Bacterial cellulose (Bacterial cellulose, BC) is a class of extracellular microbial cellulose, with plant fibers and animal fibers, it has a high water holding capacity, high crystallinity, fine mesh structure and other characteristics ultrapure (Naoto K et al.2007; Wu RQ et al.2010), in the food industry, paper industry, chemical industry, pharmaceutical industry and other areas with high use value and a very wide range of commercial applications prospects (Vandamme EJ et al. 1998; Jonas R et al.1998). However, due to its lower yield, higher production costs, its application has been a greater restrictions. Improve bacterial cellulose production, reduce production costs is bacterial cellulose research. Therefore, this study using high-pressure mutagenesis techniques, access to high-yield strains, explore high hydrostatic pressure treatment on the properties of J2 strains, provide a theoretical basis for the high mutagenic; optimized medium and high-yielding strains for the industrial production of bacterial cellulose laid foundation. The main results are as follows: ① the use of high hydrostatic pressure on bacterial cellulose producing bacteria J2 processing, found that high hydrostatic pressure on the strain J2 obvious lethal effects and mortality of J2 strains with increasing treatment time, as dealing with stress The temperature increased. ② high hydrostatic pressure treatment morphogenetic strains survived a certain degree of change, Bacillus somewhat shorter length, indicating that high hydrostatic pressure treatment to the smaller size of J2 strains. Strain J2 by ??high hydrostatic pressure treatment, although no obvious characteristics change, but after high hydrostatic pressure treatment strains utilize different carbon and nitrogen sources, high hydrostatic pressure treatment of bacterial cellulose production strains was significantly improved. After screening, a higher yield of a strain of bacterial cellulose J2After (referred J2A), which is a strain of bacterial cellulose production J2Before (referred J2B) of 1.485 times, and the growth rate is significantly faster. ③ high hydrostatic pressure treatment strain J2A during fermentation fermentation parameters have undergone some changes during fermentation cell density is significantly higher than the static pressure before the treatment, the high hydrostatic pressure treatment strain J2A fermentation process the acidity is less than before the treatment of high hydrostatic pressure, and in the fermentation process the high hydrostatic pressure treatment, the strain of the carbon source utilization of nitrogen is higher than before the treatment. ④ determine the optimal culture conditions of fermentation, namely: a 20-22h shake culture seed culture was inoculated with 9% a fermentation medium access, static culture 8d, the highest yield of bacterial cellulose. ⑤ yield have been optimized fermentation medium: 3% of the carbon source (glucose: sucrose = 2:1), yeast extract 0.5%, K2HPO40.08%, MgSO41.62%, FeSO40.36%, ZnSO40.03%, lemon acid, 0.05% to 0.7% in ethanol, under the conditions obtained by fermentation of the original bacterial cellulose 2.85 times based on the fermentation medium. ⑥ using high-speed homogenizer, ultrasonic, microwave, four kinds of alkali treated yeast, yeast found: water = 18:100, the bacterial cellulose production reached the highest value, which is the best ultrasonic broken effect, yeast fermentation production of bacterial cellulose obtained higher yields, reaching 26.081g/100mL medium. ⑦ ultrasonic treated waste yeast added salt MgSO4, ZnSO4, FeSO4, K2HPO4, we found that the production of bacterial cellulose salts MgSO4 has a certain extent, while adding ZnSO4, FeSO4, K2HPO4 when the production of bacterial cellulose There are certain role, especially for cellulose production FeSO4 role in promoting the more obvious, and in the FeSO4 concentration of 0.1%, the bacterial cellulose production lines in the highest value 34.084g. ⑧ use yeast fermentation resulting bacterial cellulose membrane metric has not changed the basic nature of much change, are high water content, with some rehydration rate of cellulose membrane.
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