Xylanase is produced from GJY-08 strain by solid-state fermentation. The influence of fermentation time, the initial pH, the temperature, the ratio of wheat bran to corn stalk, nitrogen sources and inoculation amount of the stain on xylanase production were studied. The optimum conditions of xylanase production from GJY-08 strain are as follows: fermentation time 4 d, the initial pH 4.5, the temperature 30 ℃, the ratio of wheat bran to corn stalk 7∶3, nitrogen sources carbamide, inoculation amount 3 mL, the ratio of culture medium to water 1∶2.

The experiment shows that it is feasible to determinate the chemical oxygen demand(COD) of the water from styrene condensate stripper by Fushun chemical plastic plant. We Compared the rapid determination method by COD tester and assay. These results show that the accuracy and precision of relative standard deviation (RSD) is between 0.0%～5.0% through the calculations of the standard addition recovery rate and the measurements of the standard sample. These results meet the requirements of the water quality monitoring in laboratory. Therefore, the above method can be promoted for application.

Three strains of bacteria, which had a strong antibacterial activity, were selected from the soil. The strain of XY-2 had the strongest inhibition against Staphylococcus aureus, Bacillus subtilis, Botrytis cinerea, Streptococcus mutans, E. coli. According to the analysis of morphological characteristics, training characteristics, physiological, and biochemical characteristics of XY-2, it was identified as Bacillus licheniformis. The compositions of fermentation medium of XY-2 were optimized by the orthogonal test. The results show that the optimized medium are as follows: ρ(corn starch) 20 g/L, ρ(soybean powder) 90 g/L, ρ(corn steep liquor) 7 g/L. Under these conditions, the concentration of viable cells in fermentation broth can reach 9.67×10 ⁸ cfu/mL.