香菇复配氨基酸培养基优化及其对香菇菌丝生长生理的影响

Optimization of compound amino acid medium for Lentinula edodes and the effect on mycelial growth and physiology

摘要:

【背景】L-氨基酸能够提供香菇生长发育的部分养分需求，利用外源添加氨基酸的方式对香菇生长基质进行优化，对于香菇产业的增产提质具有积极的发展意义。【目的】利用外源添加丙氨酸(Ala)、丝氨酸(Ser)和天冬酰胺(Asn)的方式改善培养基成分，并探究复配氨基酸促进香菇生长的可能代谢途径。【方法】在三因素三水平上，通过响应面法对复配氨基酸的添加浓度进行优化，并对优化后培养基的香菇菌丝进行一系列生理指标测定。【结果】以香菇菌丝生长速度为响应值，筛选出复配氨基酸Ala、Asn和Ser的理论最佳添加浓度分别为174.711、113.826和5.661 mg/L，通过试验验证，结果表明此配方可有效促进香菇菌丝生长。与PDA培养基相比，复配氨基酸培养基中的菌丝丙酮酸(pyruvic acid，PA)和蛋白质含量更高，而且该配方可以显著提高香菇菌丝中谷草转氨酶(glutamic oxaloacetic transaminase，GOT)和谷丙转氨酶(glutamic pyruvic transaminase，GPT)活性，并减少丙二醛(malondialdehyde，MDA)的积累。【结论】此研究为香菇培养基的改良以及氨基酸的促进生长机理提供理论参考。

关键词:香菇;氨基酸;外源添加;响应面法

Abstract:

[Background] L-amino acid supports the growth and development of Lentinula edodes as a nutrient. It is of great significance for the high-production and high-quality development of L. edodes industry to optimize the growth substrate of L. edodes by adding amino acids. [Objective] Exogenous alanine (Ala), serine (Ser), and asparagine (Asn) were used to improve the medium, and the possible metabolic pathway of the compound amino acids to promote the growth of L. edodes mycelia was explored. [Methods] The three-factor, three-level Box-Behnken design was employed to optimize the concentration of the amino acids, with the evaluation indicator of mycelial growth rate, and a series of physiological indexes of L. edodes mycelia in the optimized medium were determined. [Results] The theoretical optimal concentration of Ala, Asn, and Ser was 174.711 mg/L, 113.826 mg/L, and 5.661 mg/L, respectively, and the formula was verified to effectively promote the growth of L. edodes mycelia. Compared with potato dextrosa agar (PDA), the optimized medium enabled high content of pyruvic acid (PA) and protein, significantly high activity of glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT), and low content of malondialdehyde (MDA) in L. edodes mycelia. [Conclusion] The study provides a theoretical reference for the improvement of L. edodes medium and the mechanism of amino acids promoting mycelial growth.

Key words:Lentinula edodes;amino acid;exogenous addition;response surface methodology