Department of Microbiology, University of Port Harcourt, P.M.B. 5323, Port Harcourt, Rivers State, Nigeria; Department of Wcrobiology, Federal University of Technology, P.M.B. 1526, Owerri, Imo State, Nigeria
Okerentugba, P.O., Department of Microbiology, University of Port Harcourt, P.M.B. 5323, Port Harcourt, Rivers State, Nigeria; Anyanwu, V.E., Department of Wcrobiology, Federal University of Technology, P.M.B. 1526, Owerri, Imo State, Nigeria
The present study was conducted to evaluate citric acid production by a novel Penicillium sp. ZE-19 and its UV treated strain Penicillium sp. UV-7 using sucrose and fructose based media as sources of carbon and energy. Triplicate fermentations were carried out in shake flasks at 200 rpm and 28±2°C for 144 h and samples were analysed at a twelve hourly interval. The findings indicated that both organisms utilized fructose and sucrose for citric acid and biomass productions. However, both strains produced higher citric acid concentration on sucrose medium than on fructose medium; since higher citric acid concentration (CA; 22.5±0.29-23±0.1 g L-1), specific citric acid production rate (qca; 0.036-0.038 g/g.h-1) and citric acid yields (YCA/S; 0.32-0.33 g g-1) were obtained from medium containing sucrose after 144 h of incubation and these values were significantly higher (p<0.05) compared to their values under fructose medium. Interestingly, the concentrations of biomass produced by both strains on fructose and sucrose media were significantly not different (p>0.05). Although, the attempt to improve the Penicillium sp. ZE-19 gave a negative result, the authors suggest further strain optimization strategies. This study therefore, confirms a novel strain which could be used for possible commercial citric acid bioprocess using sucrose based medium. © 2014 Academic Journals Inc.