【作者】 杨永彬；

【导师】 林跃鑫；

【作者基本信息】 福建师范大学 ， 生物化学与分子生物学， 2004， 硕士

【摘要】 本文以产碱性纤维素酶的浅黄金色单胞菌(Chrysemonas Luteola)FQ为出发菌株，利用紫外线(UV)和甲基磺酸乙酯(EMS)对其进行复合诱变，经过两代诱变，获得一株产碱性纤维素酶较高的变株FQ2，其产碱性纤维素酶的能力从原来的156.6lu／ml提高到325.45u／ml。同时对变株的培养基成分和发酵条件进行了调整和优化，使其产内切β-1，4-葡聚糖苷酶的能力进一步得到增强，此外利用硫酸铵沉淀、SephdexG-100、DEAE-Sepharose Fast Flow等层析技术对其产的内切β-1，4-葡聚糖苷酶进行了分离纯化和理化性质的研究，结果表明其产生的内切葡聚糖苷酶在碱性条件下具有较好的酶活稳定性。更多还原

【Abstract】 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 .更多还原