A fungus CQ31 isolated from soil samples was identified as Chaetomium sp.. This strain produced effectively xylanases utilizing several liguocellulosic materials in the solid-state fermentation (SSF), and corn straw was the best carbon source. The results of single-factor-experiment showed that the corn straw as the carbon source, tryptone as the nitrogen source, initial moisture content of 80% and initial pH 9.0 were the optimal conditions for xylanase production. Under the optimized conditions, it produced xylanase which was 4897 U/g dry substrate while mannanase was 803 U/g dry substrate after 7 days of cultivation. Therefore, xylanase and mannanase production by Chaetomium sp. CQ31 in SSF possess potential for commercial applications.

Animals ; Biliary Tract ; abnormalities ; diagnostic imaging ; Cats ; Cholangiography ; Disease Models, Animal ; Female ; Liver ; metabolism ; pathology ; Liver Diseases ; diagnostic imaging ; etiology ; metabolism ; Male ; Malondialdehyde ; metabolism ; Mitochondria, Liver ; diagnostic imaging ; pathology ; Pancreatic Ducts ; abnormalities ; diagnostic imaging

Objective To investigate the source of the first human case of avian influenza A (H5N1) infection in Beijing. Methods Interviewing the relatives of the case and other key persons, collecting and detecting samples of related biological, epidemiological and environmental data of the case were conducted. Later, the infection source was thoroughly investigated. Results The case ever contacted a slaughtered duck 5 days prior to the onset of illness, and the duck was bought from a stall of a wet market in Yanjiao area of Hebei province. Ten environmental samples were collected in this stall and the neighboring stall of the market. Another 6 samples were tested positive for H5N1 virus by PCR method, with 5 virus strains isolated. The whole-genome sequencing indicated that the amino acid homology between the H5N1 virus strains from the environment and the virus isolated from the case reached 99.8%-100%. Conclusion From both epidemiological and virological evidence, it was proved that the first human case of avian influenza A (H5N1) infection in Beijing was infected by a duck that carrying H5N1 virus the case contacted 5 days proceeding the onset of illness.