摘要
从土壤中筛选获得了1株木糖醇高产菌株,该菌株发酵玉米芯水解液后获得的发酵液,通过离心去除菌体,用紫外分光光度法测得木糖醇产量。采用摇瓶发酵对发酵工艺条件进行优化,通过测定发酵液中木糖的残留量、木糖醇的产量、木糖醇的转化率来确定最佳的发酵工艺。结果表明,木糖醇的产量由最初3.12g/L增加到8.79g/L,转化率由15.6%增加到43.95%;优化后,最佳培养基条件为:选用木糖质量浓度为20g/L的玉米芯水解液为碳源,质量浓度为2.5g/L的蛋白胨和2.5g/L的酵母浸膏作为氮源,质量浓度为3.0g/L的KH2PO4,4.0g/L的NaCl,0.5g/L的MgSO4·7H2O,最佳发酵条件为:摇瓶发酵装液量80mL/250mL,转速160r/min,pH值为5.0,发酵温度30℃,发酵时间44h,在此条件下,木糖醇最大产量是13.84g/L,木糖转化率达69.0%。该菌株经初步研究,显示了良好的研究潜力和应用前景。
Through screening, a high yield strain of xylitol from the soil is obtained, the fermentation broth is obtained by the strain fermented corncob hydrolyzate, the bacteria is removed by centrifilgated, the xylitol production is measured by ultraviolet spectrophotometry. Using shake flask fermentation conditions on the optimization of fermentation technique, by means of measuring the residual amount of xylitol broth, the xylitol output, and the transformation efficiency of xylitol to determine the best fermentation process. The high-yielding strain of xylitol screened and obtained from the soil, by UV mutagenesis, xylitol production from the initial 3.12 g/L to 8.79 g/L, transformation efficiency from 15.6% to 43.95%, after optimized, the best medium conditions are that adoption xylose concentration 20 g/L of corn cob hydrolyzate as the carbon source, 2.5 g/L peptone, 2.5 g/L yeast extract as nitrogen source, 3.0 g/L KH2PO4, 4.0 g/L NaCl, 5 g/L MgSO4·7H2O, the best fermentation conditions are that the shake flask fermentation liquid volume is 80 mL/250 mL, the speed is 160 r/rain, pH is 5.0, fermentation temperature is 30 %2, and fermentation time is 44 h. In these conditions, the maximum yield of xylitol is 13.84 g/L, xylose transformation efficiency is 69.0%. Through an initial investigation on this strain showes that it will have a good research potential and application prospects.
出处
《农产品加工（下）》
2010年第7期17-21,共5页
Farm Products Processing
基金
云南省科技厅社会发展科技计划项目(云烟科[2009]200号)
关键词
木糖
术糖醇
工艺优化
xylose
xylitol
technology optimization
