Screening of a high xylanase producing strain and the study on the conditions for xylanase production

A high xylanase producing strain of APS 35 that can efficiently degrade hemicellulose was screened from 46 strains stored in our lab.The xylanase activity was up to 31.801 IU·g-1 which was 4.91 times higher than APS 02(control).The results of optimization of fermentation conditions showed that the optimum conditions that APS 35 produced xylanase with rice straw as the substrate were culture temperature 28 ℃,inocubation time 3-4 days,straw powder and wheat bran ratio 4∶1,inoculation ratio 10%,yeast extract as nitrogen source(the amount of total nitrogen 0.4%),pH 4.0,Tween-80 concentration 0.4%.Under these conditions,the xylanase activity was 32.024 IU·g-1,no significant difference from prior to optimization.