Screening Of Strain Producing Alkaline Cellulase And Studies On The Characteristics Of The Enzyme

Alkaline cellulase, mostly known as "endo-1,4-β-D-glucanase", is a popular enzyme which is extensively used in the washing powders and textile industry for its strong ability of removal of dusts and its promising biofurnishings .However,the yield of this enzyme in most of microorganisms is not desirable. In order to improve the yield of Alkaline cellulase production in Chrysemonas Luteola, we screen a strain henceforth referred to as FQ2 from the liberary of mutants by treating the Chrysemonas Luteola with UV as well as the combined mutagen of EMS. Compared with the original strain Chrysemonas Luteola, the mutant FQ2 has a siganificant increase in the production of Alkaline cellulase. The purification and characterization of endo-1,4-β-D-glucanase from the FQ2 are further studied .The results are as follows:1 .By exposing the Chrysemonas Luteola to the mutagen of UV and EMS, we screen a mutant strain FQ2 which significantly increase the production of alkaline cellulase, going up to 325.45u/ml from the original 156.61u/ml in strain Chrysemonas Luteola. The optimal culture medium for the FQ2 are 3%rice bran, 0.5%yeast extract, 0.5% KH2PO4, 0.5 %NaCl and a culture conditions of initial pH8.0,constant temperature 32℃ and rotary shaker 200r/min is preferred for FQ2 . A medium capacity of 70ml and an inoculums concentration of 8% also contribute to the production of endo1,4-β-D-glucanase in FQ2.2.The purification of endo-1,4-β-D-glucanase from FQ2 is processed by the use of 60%(NH4)2SO4, SephdexG-100 gel filtration DEAE-Sepharose FastFlow ion-exchange chromatogaraphy in order and the enzyme was purified12.4 folds. The enzyme was characterized by demonstration of optimal activity at50Cand pH7.0 and an approximate molecular weight of 45000u determined by SDS-PAGE. The pH range of the enzyme showing the activity is from pH5-l 1 and most of the enzyme activity can be maintained at pH7-10. The cn/.yme activity can be enhanced by the metal irons such as Ca24 and Mn2+ if exposed to a proper concentration while the Pb2+ and Hg2+ serveed as inhibitors .