优化培养条件对提高香菇漆酶产量的研究

Study on Optimization of Culture Conditions for Improved Production of Lentinula edodes Laccase

对香菇发酵产漆酶条件进行了优化并研究了部分漆酶性质.结果发现静置培养优于振荡培养; pH值≥5.6时香菇菌体基本无法生长,香菇最适生长及产酶pH值为3.5; 20 ℃低温有利于香菇漆酶生长,但最适产酶温度是 25 ℃; Cu^2＋浓度为0.2～1.0 mmol/L 时有利于香菇漆酶的合成,其中 0.4 mmol/L 是香菇产漆酶的最佳铜离子浓度,当铜离子终浓度超过 5 mmol/L 时,严重抑制香菇菌丝的生长;除了2,5-二甲基苯胺之外,阿魏酸、愈创木酚、没食子酸、黎芦醇等诱导剂促进香菇合成漆酶的作用不明显,反而会抑制菌丝生长;Tween-80的加入不利于漆酶合成.香菇漆酶在 60 ℃条件下保温 1 h 后仍残余了 2 % 的活力;以2,2＇-连氮-双（3-乙基苯并噻唑-6-磺酸）（ABTS）为底物的最佳反应温度是 65 ℃,最适反应pH值为2.2（柠檬酸-磷酸氢二钠缓冲液体系）.

Optimization of culture conditions for laccase production by xianggu mushroom （Lentinula edodes） was carried out and part characteristics of the crude laccase was investigated. Static cultivation was better than shaking cultivation for preparation of laccase from the edible mushroom. When culture pH value was ≥ 5.6, L, edodes was basically unable to grow. The best activity of laccase was found when pH value was around 3.5 and culture temperature was 25℃, though 20 ℃ was benefitial to the growth of mushroom. The concentration of Cu^2＋ from 0. 2 to 1.0 mmol/L improved laccase production by L. edodes, while the optimal concentration of Cu^2＋ was 0. 4 mmol/L. However, when concentration of Cu^2＋ exceeded 5 mmol/L, the growth of L. edodes was inhibited, Except 2,5-dimethoxyaniline, other four inducers, namely： ferulic acid, 2-methoxyphenol, gallic acid （3,4,5- trihydroxybenzoic acid） and veratryl alcohol （3,4-dimethoxybenzylalkohol） did not increase laccase activity significantly, but inhibited the mushroom＇s growth instead. Addition of Tween-80 affected the yield of laccase negatively. 2 % of the activity of L. edodes laccase was retained after one hour incubation at 60 ℃. Using 2,2＇-azino-di-（ 3-ethylbenzothiazoline-6-sulfonic acid） （ABTS） as substrate, optimal reaction temperature of the laccase was 65 ℃ and optimum pH value was 2.2.