宇佐美曲霉L-336酸性蛋白酶2m^3罐中试发酵研究报告

Studies on the Fermentation Process of Acid Protease by Asp.usamii L 336 in 2m 3 Agitation Fermentor

宇佐美曲霉栗色变种Ｌ－３３６是分泌高单位酸性蛋白酶的生产菌，在摇瓶小试工艺基础上进行２ｍ３罐发酵中试，结果表明：较优发酵培养基（％）为黄豆粉４．３，玉米粉１．０，鱼粉０．７，蚕蛹水解液１０，Ｎａ２ＨＰＯ４０．２，ＣａＣｌ２０．５，ＮＨ４Ｃｌ１．０，豆油１．６；风量为０～２５ｈ时１∶０．４ｖ／ｖ／ｍ，２５～５０ｈ时１∶１．０ｖ／ｖ／ｍ，５０ｈ后１∶１．３ｖ／ｖ／ｍ；接种量１０％，温度３１℃，搅拌转速２００ｒ／ｍｉｎ，发酵周期７５ｈ。在上述条件下，发酵酶活力稳定在５５００ｕ／ｍｌ左右。

Asp.usamii L 336 could produce high yield acid protease,whose fermentation conditions in 2m 3 agitation fermentor were studied on the basis of agitation flask tests. The experimental results showed that the most suitable fermentation medium consisted of 4.3% bean flour, 5% maize flour, 0.7%fish flour,10% silkworm chrysalis hydrolyzat, 1.6% bean oil, 0.5% CaCl 2, 1.0% NH 4Cl, and 0.2% Na 2HPO 4 with 5% inoculum size, 31℃±1℃,200 r/min agitation speed,and 75h fermentation period. Air condition was 1∶0.4 V/V/m before 25h, however, it became 1∶1.0 V/V/m from 25h to 50h and 1∶1.3 v/v/m after 50h. Under such circumstances, the acid protease enzyme activity of Asp.usamii L 336 was about 5 500 u/ml.