Breeding of xylanase producing strain with chaetomium globosum by ultraviolet mutation

Xylanase has important potential applications value.In order to gain the strain which has stable genetic traits to produce xylanase,we took the xylanase activity as evaluation index,used ultraviolet mutation method,determined the time of ultraviolet irradiation by single factor experiment.By preliminary screening of Ultraviolet mutation strains in the medium containing xylan,the xylanase activity was measured by DNS methods.Screen was then repeated in the mutation strains.The highest xylanase activity mutant strains were selected to determine their activity and the genetic stability.The results of this experiment showed that the power of ultraviolet lamp was 20W,exposure distance was 30cm and exposure time was 120s.The fatality rate of chaetomium globosum was 92.35%.Under these conditions,15 mutant strains with higher yield of xylanase was selected.The strain Z30-56 had the highest xylanase activity and highest yield was 9850IU/mL,increasing 53.7% compared with the original strain.The genetics of the strain was also very stable.