He-Ne激光诱变香菇原生质体选育速生高产菌株及香菇液体深层发酵工艺研究

【作者】 段东霞；

【导师】 陈五岭；

【作者基本信息】 西北大学 ， 微生物， 2002， 硕士

【摘要】 本文采用激光技术与微生物原生质体育种技术相结合，选育香菇速生高产新菌株。并研究了所选育的新菌株在深层培养条件下的最佳发酵工艺条件，为香菇工业化生产液体菌种打下了良好的基础。 实验结果表明，香菇原生质体制备与再生的最佳条件为：采用对数生长期的菌体，2％溶壁酶，在32℃下酶解2.5—3hr，原生质体产率达到2.81×10⁶个/mL；制备的原生质体，在含0.6mol/1MgSO₄的高渗培养基上培养，再生率为3.24％。 采用波长为632.8nm的He-Ne激光，以不同剂量辐照香菇135原生质体，所选的变异株经酯酶同工酶谱分析，其酶带条纹数，迁移率等均发生了显著变化；斜面培养，液体培养分析表明变异株与对照相比生长速率和生物量发生了明显变化。说明其遗传物质发生了改变，且不同剂量的He-Ne激光对香菇原生质体的诱变效果有差异。表明激光对香菇是一种有良好应用前景的诱变剂。 本文从工业化角度出发，研究了香菇的液体深层培养情况，考察了培养过程中还原糖，氨基氮，pH等参数随菌丝生长的变化规律；研究了不同培养基配方，不同接种方式，对菌丝量的影响，筛选出最佳培养基配方，发酵工艺条件。更多还原

【Abstract】 In this paper, with laser-irradiation and protoplast technique, the mutants were screened whose mycelial growth speed was increased. We studied the submerged cultivation of the mutants, offering the base of modern fermation technique.The result showed that protoplasts were easier to be obtained when Lentinus edodes were cultured to the mid-later exponential stage, while the mycelium co-treated with 2% Lywallzyme, at 32. And the regeneration frequencies reached to 3.24% on hyperosmotic medium containing 0.6M MgSCXHe-Ne laser (A =632.8nm) irradiated protoplasts for different time. The analysis of esterase isoenzyme indicated that the mutants’ esterase is-enzyme patterns were of great difference from the starting strain. Solid culture, liquid culture told the mutants’ mycelial growth speed and biomass were different from starting strain too. So it was concluded the mutants genetic substances had changed and different doses had different effect on protoplasts. Laser is a good mutagen.From the industrial angle, we studied the submerged cultivation of the mutants; discussing the law of a series of parameters, for example, reducing sugar, amino nitrogen, pH with the change of mycelia growth in the course of activation. After studied the effect on wet mycelial amount of the different medium, different inoculation methods, we got the best fermentative media and fermentative procedure.更多还原