丝状真菌纤维素酶合成机制的研究

丝状真菌产生的纤维素酶被认为是最有应用前景的,但就目前酶生产效率来看,离实际应用还有很大的差距,需要对酶的合成调节机制有更为全面和深刻的了解。纤维素酶的生物合成受诱导和阻遏双重控制,酶的生产既有赖于低廉的保持一定浓度诱导物的存在,又必须清除分解代谢产物对酶合成的阻遏,其中的详细机制有待进一步的阐明。真菌纤维素酶的分泌也是相当复杂的,在酶的分泌过程中,酶会发生例如糖基化等一系列变化。提高纤维素酶的活力测定方法的准确性,使其进一步规范化,是研究纤维素酶工作的另外一个重要的领域。随着现代生物学朝着分子水平的不断发展,分子生物学的许多方法也越来越多地被应用于纤维素酶的研究中,并取得了重要进展。对真菌纤维素酶合成调节机制的深入研究,将为提高纤维素酶产量,推动应用工作的发展打下理论基础。

BIOSYNTHESIS REGULATION OF CELLULASE IN MYCELIAL FUNGI

The fungus can produce extra cellular complex system which can hydrolyze cellulose to soluble sugars. The biosynthesis of cellulase in fungi is regulated by the induction—represion mechanism, and it related to the growth of the organisms. Many materials can induce the syntheisis of cellulase, the inducers interact with the repressor and render the repressor inactive, the results being enzyme biosynthesis. β—glucosidase play an important role in the induction of enzyme synthesis. The cellulase is repressed by glucose and other readily metabolizable sugars in the growth medium. The structural gene expression is repressed by the accumulation of catabolites. The cellulase first occurs in the endoplasmic reticulum and release outside the cells by the specific and unspecific system. The age of mycelial growth and the presence of some materials which affact the cell wall structure relate to the amount of enzyme protein release. In the research of cellulase production and secretion, the enzyme activity assay needs to be specific and easily. Now the production cost of enzyme is the main obstruct of making cellulase to practical use. So to improve the productivity of enzyme is present research work. The development of biological technology which can be used as producing cellulase is also needed.