响应面分析法优化香菇多糖发酵培养基

Optimization of submerged cultivation medium components for lentinan production by Lentinula edodes using response surface methodology

香菇多糖是香菇中分离出的一种重要的具有生理活性的物质。采用深层发酵技术培养香菇菌丝体生产多糖,可利用农副产品作原料,成本低,周期短,易于大规模生产。采用响应面优化香菇Lentinula edodes135发酵培养基产多糖,首先Plackett-Burman设计对培养基8因素进行筛选,获得影响多糖产量的3个主要因素:葡萄糖,鱼粉和KH2PO4;然后用最陡爬坡路径逼近最大响应区域;最后通过Box-Behnken设计及响应面分析确定了主要影响因素的最佳浓度:葡萄糖2.2533%,鱼粉0.9756%,VB10.003%,NaCl0.8%,MgSO4·7H2O0.1%,FeSO4·7H2O0.04%,KH2PO40.0993%,初始pH值5.5。在优化后的培养基中,粗多糖产量为2.33g/L,实测值与预测值的误差为+3.61%,比初始培养基多糖产量提高1.91倍。

Lentinan is the most important polysaccharide isolated from Lentinula edodes, with unique biological activities. Production of lentinan by submerged cultivation utilizing subsidiary agricultural products as raw material can reduce the cost, and shorten production cycle, and it is easy of large scale manufacture. Response surface methodology （RSM） was used to optimize L. edodes 135 submerged cultivation medium for lentinan production. Plackett-Burman design was used to evaluate the influence of related eight factors, and three factors playing the important roles in the medium, including glucose, fish powder and KH2PO4, were selected. Steepest ascent path was adopted to approach the optimal region, and then the Box-Behnken design and response surface analysis were used to determine the optimal levels of the main factors. As a result the optimal conditions were analyzed as： glucose 2.2533%, fish powder 0.9756%, VB1 0.003%, NaCl 0.8%, MgSO4·7H2O 0.1%, FeSO4·7H2O 0.04%, KH2PO4 0.0993%, and the initial pH value of 5.5. The yield of lentinan produced by L. edodes in the optimal medium increased 1.91 times as compared with that in the initial medium and reached 2.33g/L, with only ＋3.61% differences from the forecast by RSM.