对羟基苯甲醛等3 种天麻成分对灰树花胞外多糖生物合成的影响

在灰树花液体发酵体系中，分别添加不同量的天麻素、对羟基苯甲醇和对羟基苯甲醛3 种天麻成分，分析这3 种成分对灰树花菌体生长和胞外多糖（exopolysaccharide，EPS）合成的影响，采用苯酚-硫酸法测定胞外多糖含量。结果表明：适宜质量浓度的这3 种天麻成分均能促进灰树花菌体生长和胞外多糖的生物合成，其中对羟基苯甲醛添加量为0.15 g/L时效果最佳，并且略低于体积分数7%天麻醇提取物。动态分析0.15 g/L对羟基苯甲醛和7%天麻醇提取物对灰树花EPS合成促进作用的结果表明：在整个发酵过程中，二者促进灰树花EPS生物合成的效果基本一样，并且从发酵第7天开始，二者的EPS产量均显著高于空白组（P＜0.05）。采用高效液相色谱法动态测定发酵期间对羟基苯甲醛含量变化，结果表明：在发酵的第5天，对羟基苯甲醛基本被完全吸收，而此时灰树花EPS开始大量积累。因此，灰树花可利用对羟基苯甲醛来促进EPS的生物合成。

Effect of p-Hydroxylbenzaldehyde and Other Main Ingredients of Rhizoma gastrodiae on the Biosynthesis of Exopolysaccharide by Grifola frondosa in Submerged Culture

To test the stimulatory effects of three ingredients of Rhizoma gastrodiae on the biosynthesis of exopolysaccharide
(EPS) by Grifola frondosa in submerged culture, gastrodin (GA), p-hydroxybenzyl alcohol (HA) and p-hydroxylbenzaldehyde
(HBA) were separately added at various concentrations into the culture medium. The EPS concentration in the culture
supernatant was determined by phenol-sulphuric acid assay. The results showed that all three additives had an effective
stimulatory effect on mycelial growth and EPS production. Among them, the addition of p-hydroxylbenzaldehyde at 0.15 g/L
exhibited the best effect, although slightly inferior to 7% (V/V) of the 75% ethanol extract of R. gastrodiae. Furthermore,
kinetic analysis suggested that the EPS production curves with 0.15 g/L p-hydroxybenzaldehyde and 7% (V/V) of the
R. gastrodiae extract over the entire fermentation process were substantially same, producing significantly more EPS than
the blank group from the 7th day onwards (P < 0.05). As determined by high performance liquid chromatography (HPLC),
dynamic changes in the concentration of p-hydroxylbenzaldehyde during the fermentation process showed that on the 5th
day, p-hydroxylbenzaldehyde was completely absorbed and EPS began to accumulate in large quantity. Therefore, Grifola
frondosa could utilize p-hydroxylbenzaldehyde to promote the biosynthesis of EPS.