Optimization of biomass and pigment production by Penicillium species isolated form virgin forest floorAuthor(s): M.Chutia, G.U.Ahmed
Extracellular pigment-producing ascomycetous filamentous fungi belonging to the genera Penicillium was obtained from soil and its optimal culture conditions investigated. The effect of nutrient culture media, pH and temperature on growth, sporulation and pigment production of three Penicillium species isolated from virgin forest floors of North east India was studied to optimize the mycelial growth and secondary metabolite production. Culture media significantly affected the growth, sporulation and conidial discharge of the species. The average colony growth of the three Penicillium species was higher in Malt Extract Agar (MEA) medium (4.1±0.59cm) whereas spore production was higher in Potato Dextrose Agar (PDA) medium (87.3±3.1). The optimal culture conditions for pigment production were as follows: inoculumÂs age, 7 days; temperature, 25 °C; pH, 6 and medium, PDA. Mycelial growth had also a significant correlation with the media pH and incubation temperature together with the pigment production. Under the optimal conditions obtained in the flask culture tested, the isolates secreted coloured pigments into the culture medium which was dependent on the pH of the solution. The high concentration of pigments produced by Penicillium species may be utilized for commercial production of pigments or the metabolites having industrial importance.