响应面法优化以桑枝为主要基质的灵芝栽培配方

Optimization of cultivation formula for Ganoderma lucidum based on mulberry branches using response surface methodology

目的利用响应面法对以桑枝为主要成分的灵芝栽培培养基配方进行优化。方法以苯酚-硫酸法测定灵芝子实体中的多糖含量为指标,通过Plackett-Burman(PB)实验筛选出影响栽培灵芝子实体多糖含量的主要因素,然后用最陡爬坡试验、中心组合设计和响应面法对影响灵芝多糖含量的显著因素进行优化,利用以栽培灵芝子实体中多糖含量为响应值建立的二次回归方程模型,确定主要影响因素的最佳浓度,得到可大幅度提高灵芝子实体中多糖含量的最佳发酵培养基配方。结果确定了以桑枝为主要基质的优化后栽培培养基配方:65%桑枝屑,25%中药渣,4%玉米粉,1%蔗糖,1%石膏粉,4%麸皮,0.1%KH_2PO_4,0.1%MgSO_4·7H_2O,0.01%VB1。验证实验表明使用优化后的培养基生产的灵芝子实体中的多糖含量高达8.35%,是基础培养基生产的灵芝子实体多糖含量(3.17%)的2.63倍。结论对灵芝栽培培养基配方采用响应面中心组合设计,可以有效地对栽培培养基进行优化。

Objective To optimize cultivation formula of Ganoderma lucidum based on mulberry branches by means of response surface methodology. Methods Using polysaccharide content tested by phenol-sulfuric acid method as an index, a Plackett-Burman（PB） design was applied to screen potential key factors associated with polysaccharides content in fruit body of Ganoderma lucidum. Then, the steepest ascent test, central composite design and response surface methodology were applied to optimize the significant factors influencing the polysaccharide content. Finally, the optimal medium formula was obtained with a significantly improved polysaccharide content according to a quadratic regression equation model established by fruit body＇ s polysaccharide content as response values. Results The optimized cultivation formula based on mulberry braches was dertermined： 65% mulberry branches sawdust, 25% Chinese herb medicine residue, 4% corn flour, 1% sucrose, 1% gypsum powder, 4% bran, 0.1% KH2PO4, 0.1% MgSO4 · 7H2O, 0.01% VBt. The verification experiment results showed that the polysaccharide content was obtained 8.35% in the fruit body by the optimized medium, and a 2.63-fold of that （3.17% ） cultured by the original basic medium. Conclusion The central composite design and response surface methodology can be used to optimize cultivation formula for Ganoderma lucidum.