【摘要】 【目的】从土壤中分离筛选获得了一株具有高产木聚糖酶能力的真菌Sp1。【方法】经过28SrDNA测序鉴定为赭绿青霉(Penicillium ochro-chloron)。通过对摇瓶发酵条件优化试验及酶特性研究。【结果】该菌株的最适产酶条件为:2%(W/V)粗制木聚糖+0.5%葡萄糖为碳源,0.44%KNO3+0.06%蛋白胨为氮源,发酵起始pH为5.0,150mL三角瓶装液量为40mL,转速为220r/min,28℃下培养72h木聚糖酶酶活可达387U/mL。将菌株Sp1发酵所得粗酶液经过纯化后研究其酶学特性,酶最适反应pH为4.0,最适反应温度为55℃,在40℃,pH2.2～6.0,酶活性稳定。终浓度为0.01mol/L的Na+、K+和Zn2+对酶活有促进作用。【结论】所筛选的Sp1菌株具有较好的应用前景。更多还原

【Abstract】 [Objective and Method]The aim of this study was designed to screen a strain of fungi named Sp1 from the soil.It was identified as Penicillium ochro-chloron by morphological identification and 28S rDNA sequence analysis.[Result]The results showed that the optimum conditions for Sp1 producing xylanase were mixture of 2%(W/V)xylan,0.5%glucose,mixture of 0.44%KNO3 and 0.06% peptone,40 mL liquid medium in 150 mL flask which is composed of 0.2%KH2PO4,0.2%(NH4)2SO4,0.03% MgSO4·7H2O,0.03% CaCl2,0.0005 %FeSO4·7H2O,2%xylan,0.5%glucose,0.44% KNO3,the initial pH 5.0,fermentable temperature 28 ℃,200 rpm of rotation,fermentation time was 3 days,the enzyme activity of xylanase reached 387 U/mL.the crude enzyme from SP1 strain was separated and purified and indicated that the purified xylanase was endo-xylanase.The optimal pH and temperature were 4.0 and 55℃,good stability below 55℃,stable within pH 2.5～5.5.Na2+,K+ and Zn2+ can activate the activity of xylanase with final concentration of these metal ions 0.01 mol/L.[Conclusion]The screened strain Sp1 is of great value in application.更多还原