里氏木霉HC-415菌液体发酵产纤维素酶时形态学变化研究

Study of the Morphological Change of 2Trichoderma reesei HC-415 in the Liquid Fermentation Process for Cellulase Production

在30L发酵罐中研究里氏木霉HC-415菌液体发酵产纤维素酶菌体形态学变化时,发现该菌的形态变化可分为4个时期;第Ⅰ期为接种后的0～24h,菌体形态主要呈丝状伸长,较少分枝,产酶基本处于停滞期;第Ⅱ期为24～60h,菌丝体不断伸长,分枝增多,菌体变粗,酶活性增长明显;第Ⅲ期在60～132h,此期菌丝体变粗变短,并出现横隔,分枝顶部生出许多膨大的圆形结节,该期为纤维素酶活力的快速增长期和高峰稳定期;第Ⅳ期为132h后,期间菌丝体呈粗短圆状,仍有许多膨大的结节,但菌体数量逐渐变少,酶活性开始逐步下降.结果表明:里氏木霉液体发酵产纤维素酶时菌体形态与发酵液中的酶活性变化密切相关,形态学特征可作为实际生产中快速调控发酵液成熟度的重要指标。

This study addresses the morphological changes of Trichoderma reesei HC-415 in the process for cellulase production in 30 L fermenter. It was found that the morphological changes of HC-415 could he divided into four periods in the process of fermentation. The hypha morphology during the first period showed that filamentous elongation with less branching and the enzyme production was almost at a stationary phase after vaccinations within 0~24 h. Next, the mycelial length and the number of branches increased, the stem became thick and the enzyme activity significantly increased after vaccination within 24 ~60 h. Then, mycelium with septa became short and thick, and this was accompanied by the appearance of many enlargement round nodules at the top of the branches after vaccination within 60~ 132 h. This was the period of rapid growth and peak stability of cellulase activity. Finally, the number of thick and short round mycelium with many enlargement nodules declined, accompanied by the gradual decline of enzyme activity after vaccination for 132 h. The results demonstrated that a tight correlation existed between the morphological characteristics and the cellulase production and the activity of Trichoderma reesei in liquid. Furthermore, the morphological characteristics can be used as an important indicator for the regulation of fermentation broth of maturity in the production of cellulase.