对羟基苯甲醇对灰树花产胞外多糖的影响及其发酵动力学

通过向灰树花发酵液中添加不同质量浓度梯度的对羟基苯甲醇，分析其对灰树花菌体生长和胞外多糖合成的影响，并且进一步研究了添加对羟基苯甲醇后发酵液中菌丝体生长、残糖（还原糖）含量、胞外多糖产量、pH值、对羟基苯甲醇和天麻素含量的变化情况，并做动力学分析。结果表明：当对羟基苯甲醇添加量为200 mg/L时效果最佳，相比于空白组（未添加对羟基苯甲醇）使菌丝体生物量提高了22.73%，胞外多糖产量提高了10.24%，均显著高于空白组（P＜0.05）。动力学研究结果表明：在整个发酵过程中，灰树花生长从第8天趋于稳定，葡萄糖作为碳源不断被消耗并且胞外多糖逐渐合成，到第10天二者趋于稳定。此外，对羟基苯甲醇含量减少，部分转化为天麻素。

Effect of p-Hydroxybenzyl Alcohol on the Biosynthesis of Exopolysaccharide by Submerged Culture of Grifola frondosa and Fermentation Kinetics

The effect of adding different concentration gradients of p-hydroxybenzyl alcohol to the culture medium of Grifola
frondosa on mycelial growth and the production of extracellular polysaccharide in submerged fermentation. Meanwhile, we
determined changes in mycelial growth, reducing sugar (residual sugar) content, extracellular polysaccharide content, pH,
p-hydroxybenzyl alcohol and gastrodin contents in the fermentation broth of Grifola frondosa, and we also made a dynamic
analysis. Results showed that addition of 200 mg/L p-hydroxybenzyl alcohol was found to be optimal, resulting in an
increase in mycelial biomass of 22.73% and an increase in extracellular polysaccharide production of 10.24% as compared
with the control group without added p-hydroxybenzyl alcohol; both increases were significant (P < 0.05). Dynamic analysis
results showed that the growth of Grifola frondosa remained stable from day 8 onwards; glucose was consumed as the carbon
source, and residual glucose and the production of extracellular polysaccharide both remained stable from day 10 onwards.
In addition, the gastrodin content increased as a result of partial conversion of p-hydroxybenzyl alcohol into gastrodin.