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Laccase is a kind of copperish polyphenoloxidase, existed in fungus widely. Laccase is able to catalyse diverse forms of chemical reactions that involved in biology, chemistry, physic, iatrology, environics and other many fields of study. Because of its capacity of lignin degradation, laccase has application potentials and values of research in pulping and papermaking, textile fabrics, degradation of environmental pollutant, which has a comprehensive scientific future.In this paper, the writer systemically studied the filtration identification mutation breeding、optimization strain enzyme-producing condition and the degradation to bamboo fabrics, a new sort of pro-environment fabrics which has a comprehensive scientific future of laccase producing bacteria. Results are as followed:With Bavendamm reaction test and discoloration circle on oxidation zone flat being measurement indicators, filtered more than 20 samples of soil and rotten-wood, and 6 strains were found with high Lacs enzyme activity. The strain 1024 was shown to be an excellent Lacs enzyme producer with a highest activity by re-filtering and shaking bottle. Measuring the growth curve of 1024 by means of weighing the dry hypha and the results showed that the logarithmic metaphase of growth of the 1024 was 80 hours. When cultured in basic enzyme-producing medium at 30℃and shaken at 140rpm, laccase activity of no.1024 strain was 6.921 U/L on the 8th day.A higher laccase producing strain N1024j with genetic stability was obtained from 1024 by mutagenesis with N+ ion implantation (30KeV,100×1014ions/cm2,10-3Pa, 10mA,10s). Compared with N1024, the enzyme-production is up to 8.62 U/L on the 1st generation and 7.81 U/L on the 5th generation, which improved by 24.55% and 12.84% respectively.The enzyme-producing conditions were optimized by single-factor method and quadrature analysis. The results of the experiment showed the best enzyme-producing conditions were as following:peeled potato 200g, dextrose 25g, yeast extract 3.0g, KH2PO43.0g,TuWen80 O.lg, distilling water 1000ml, loading amount 50mL,culture temperature 27℃, initial pH 6.0,rotational speed 120rpm. The Laccase activity reached 15.76U/L after three days. Compared with the formal enzyme-producing condition, the enzyme activity enhanced 182.83%.Used N1024j in microbe degumming of bamboo fabrics, the degradation rate of lignin is 33.19%, and the degradation rate of holocellulose is 22.28% after 30 days and the selectivity coefficient of lignin degradation was 1.49. Bamboo fabrics samples of non-treated, 10d-treated,20d-treated and 30d-treated were analyzed with infrared spectrum. According to the related peak variety of lignin and hemicellulose, N1024j is able to highly offer a selective degradation on lignin and hemicellulose. But it was still highly lignin-laden, and supposed to be continually processed.
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