OPTIMIZATION OF CELLULASE PRODUCTION BY PENICILLIUM-OCCITANIS

The mutant Pol6 of Penicillium occitanis is an interesting strain for producing cellulases and hemicellulases, The nitrogen source and substrate that regulate cellulase production were evaluated in shake-flask and fermenter (batch and fed-batch) culture. The nature of the nitrogen source and the C/N ratio markedly affected cellulase production by P. occitanis. When nitrate was used in Mandels and Weber's basal growth medium with a C/N ratio below 20.2, it resulted in more cellulase production than from urea or ammonium sulphate. Crude substrates such as wheat bran and wheat flour residues, used in combination with a local cellulose esparto grass paper pulp as an alternative nitrogen source and cellulose substrates, also gave high cellulase yields. Greatest cellulase yields and productivity were obtained by fed-batch cultivation [23 filter-paper activity units (FPU)/ml and 168 FPUl(-1)h(-1)].