重组烟曲霉壳聚糖酶在毕赤酵母中高密度发酵表达及性质研究
The Study on High Density Fermentation of Recombinant Chitosanase from Aspergillus fumigatus in Pichia pastoris and Characterization of Recombinant Chitosanase

采用高密度发酵法在5L发酵罐中对pPIC9-csn/GS115重组毕赤酵母Pichia pastoris菌株进行发酵,壳聚糖酶的产量达到4200 U？mL-1,发酵液经乙醇浓缩、透析和阳离子交换色谱等步骤进行分离纯化,获得了纯度较高的重组壳聚糖酶.该重组壳聚糖酶与野生型壳聚糖酶对壳聚糖作用模式相同,其最终产物均为壳三糖,且其最适作用温度为60℃,最适pH值为6.0.
The recombinant Pichia pastoria strain infected with pPIC9-csn/GS115 for expression of chitosanase was high cell density cultured in a 5 L fermentor.As a result,the yield of chitosanase was 4 200 U？mL,the chitosanase fermentation product was purified to above 95% by ethanol concentration,dialysis and cation exchange chromatography.In addition,the recombinant chitosanase showed the same mode of action as the wild chitosanase,produced the final product chitotriose and were optimal at the temperature of 60 ℃ and pH of 6.0