Research on the Screening of Bacteria Decomposing High-temperature Cellulose and the Characteristics of JSU-5 Producing Cellulase

[Objective] The reference for the bacteria strain producing cellulase enzyme and its efficiency was provided.[Method] The bacteria decomposing hightemperature cellulose was screened out from cow dung and wheat straw compost.The condition of cellulase production such as carbon,nitrogen,pH value,NaCl concent-ration,the volume of liquid and so on was researched and the optimum fermentation condition was determined with orthogonal test.[Results] The bacteria strain——JSU-5,selected from 11 high-temperature bacteria of cellulose decomposition,had the highest enzyme activity.The result indicated there was the highest activity of enzyme production when the pH value was at around 6 or when the culture time was for 5 d.And also there was the highest activity of enzyme production when the wheat straw was used as carbon source,or the soybean powder was used as nitrogen source.The concentration of sodium was 0.2%.The main factor affecting the cellulose enzyme activity in medium components was carbon,water and nitrogen.[Conclusion] The best nutrition component in medium for strains——JSU-5 producing cellulase was the quantity of wheat straw,50 g/L;soybean flour,30 g/L;NaCl,2 g/L;the volume of liquid,60 ml;pH value,6.0 and the fermentation temperature,50 ℃,under which,113.4U/ml of enzyme was produced.