本文从稻田土壤中分离到一株产纤维酶活力高的X-5菌株，经形态特征及生理生化特征初步鉴定为半知菌亚门，丝孢纲，丝孢目，丛梗孢科，青霉属(Penicillium)。对青霉菌X-5菌株进行发酵培养条件的研究结果表明，以5.0%稻草粉为碳源，3.0%豆饼粉为氮源，装液量为60ml，接种量为5.0%，培养温度为26~28 ℃，初始pH 4.5~6.0，培养120 h，产酶活力最高，CMC酶活为75.72 IU/ml，FP酶活为6.68 IU/ml。

Strain X-5 which with high cellulos-producing activity was obtained and identified to be Fungi Imperfecti, Moniliales, Moniliaceace, Aspergilleae,Penicillium.. Production of cellulase was carried out by submerged fermentation with strain X-5. The results showed that the best carbon source, nitrogen source, medium volume, inoculum size, temperature, the initial pH value and culturing time were 5.0% rice straw powder, 3.0% bean cake meal, 60mL, 5.0%, 26~28 ℃, 4.5~6.0, and 120 h, respectively. Under the above conditions, the highest activities of CMCase and FPase in the fermented broth were 75.72 IU /ml and 6.68 IU/mL, respectively.