Cellulase Production by a Newly Isolated Soil Fungus Penicillium Griseofulvum A2

Rice straw is one of the most abundant resources in the world. Returning straw to field is an effective method facilitating sustainable agricultural production in many countries. However, the crop residues cannot be degraded easily due to recalcitrant structure and composition of lignocellulosic material. A straw-degrading fungus Penicillium griseofulvum A2 was isolated from rice straw culture medium and identified by morphology and ITS rRNA gene sequencing. Enzyme-producing condition of A2 was optimized, including nitrogen source ((NH 4 ) 2 SO 4 , NH 4 Cl, urea, and peptone), pH value (5.0 to 7.5), and incubation time (1 to 20 d). Results showed that P. griseofulvum A2 produced the highest CMCase (33.97 ± 0.33 U/mL) utilizing urea as nitrogen source and growing at pH 7.0-7.5 after 15 d cultivation. While, NH 4 Cl was more suitable for β-glucosidase (15.40 ± 1.77 U/mL) production under pH 7.0 condition after 10 d cultivation. The isolated fungus P. griseofulvum A2 is a good potential strains to decomposed rice straw.