不同搅拌器类型对齿毛菌发酵产漆酶的影响

Effects of different stirrers on laccase production with Cerrena unicolor

摘要:

【目的】白腐菌Cerrena unicolor Y-G07是一种不产孢子的丝状真菌，其漆酶合成与生长相偶联。应用于单细胞微生物发酵的搅拌器并不适用于白腐真菌。在此，综合考虑溶氧效果和剪切力作用，研究不同搅拌器类型对白腐菌Cerrena unicolor Y-G07发酵生产漆酶产量的影响。【方法】针对Y-G07菌株生长过程需氧量大，且对剪切力敏感的特性，订制5种不同类型的搅拌器(径向流、轴向流等)，在通气已控制在设备最大量程及转速优化的前提下，研究Y-G07在发酵生产过程中使用不同类型搅拌器对菌丝生长形态、生长速度、溶氧情况、糖代谢和漆酶合成的影响。【结果】Cerrena unicolor Y-G07菌株对不同类型搅拌器产生的发酵液流态性质和剪切力敏感，表现在菌丝体的生长形态、细胞浓度差异较大，且生长周期改变，从而影响漆酶的合成。采用六折叶DT602搅拌器最有利于该菌株形成致密度合适的网状菌丝体，菌丝体细胞浓度高，断裂少、生长状况好，漆酶的单位产量可达690 U/mL，相对于普通使用的六叶平直叶搅拌器(448U/mL)提高了54%。【结论】选择合适的搅拌器类型有利于好氧但对剪切力敏感的微生物发酵。

Abstract:

[Objective] To study the effects of different stirrers on laccase production with white-rot fungus Cerrena unicolor Y-G07 during fermentation. [Methods] Y-G07 is a non-spore forming filamentous fungus, whose laccase synthesis is coupled with its cell growth. Considering the aerobic nature and shear force sensitivity of the strain, five different stirrers were designed to compare the effects on hyphal morphology, growth rate, dissolved oxygen, glycometabolism and laccase production. [Results] Different stirrers resulted in the difference in hyphal morphology, cell concentration, growth cycle, and thus affected laccase production. The six-hinge-blade DT602 impeller formed reticular mycelia with appropriate density, high concentrations of mycelium cells and less hypha fracture during fermentation. The laccase production was increased up to 690 U/mL, which is 54% higher than that by using usual Six-flat-blade impeller. [Conclusion] Proper design of agitator in fermentor can be favorable for aerobic and shear-force sensitive microorganisms.