Research at UAF - Purification, Immobilization and Characterization of Ligninases Produced By Indigenous White Rot Fungi For Industrial Applications


Duration:      3 Year
Cost:              3.151
Funding Agency:   Higher Education Commission

Progress Reports


Abstract:
The extracellular and non-specific lignin mineralizing enzymes (LMEs) including lignin peroxidases (LiPs), manganese peroxidases (MnPs) and laccases are secreted by white rot fungi (WRF) in secondary metabolism. LMEs have extensive industrial applications including delignification of lignocellulosic biomass for fuel ethanol production, food, brewery and wine, animal feed, denim stone washing, laundry detergents, paper and pulp industries, and in bioremediation of chemical pollutants The project was planned to investigate the ligninase enzymes (MnP, LiP and Laccase) production potential of five locally isolated indigenous strains of white rot fungi Pleurotus ostreatus IBL-02, Phanerochaete chrysosporium IBL-03, Coriolus versicolor IBL-04, Ganoderma lucidum IBL-05 and Schyzophyllum commune IBL-06 using lignocellulosic agro-based residues including wheat straw, rice straw, banana stalk, sugarcane bagasse, corn stover and corn cobs in Solid State Fermentation (SSF) as well as in Liquid State Fermentation (LSF). It was observed that the maximum production of Laccasse enzyme (935.48 U/mL) was achieved with wheat straw at 7 days of solid state fermentation with fungal culture of Pleurotus ostreatus IBL-02 followed by Coriolus versicolor IBL-04 (680 U/mL) after 5 days in SSF of corn cobs as a substrate, while under LSF the enzyme production was quite low as compare to SSF. Maximum LiP activity (1535.8 U/mL) was observed in SSF of wheat straw after 10 days of incubation with Ganoderma lucidum IBL-05, followed by Schyzophyllum commune IBL-06 (783.9 U/mL) using corn stover in 8 days and  by Phanerochaete chrysosporium IBL-03 LiP (640 U/mL) using banana stalk after 5 days. Maximum production of MnP (666 U/mL) was shown by Coriolus versicolor IBL-04 in SSF of corn cobs after 5 days, followed by Ganoderma lucidum IBL-05 (643.4 U/mL) and Phanerochaete chrysosporium IBL-03 (620 U/mL) with wheat straw as substrate. In conclusion SSF of lignocellulosic substrates gave better yield of lignolytic enzymes as compare to LSF. Hence SSF was selected for further studies including optimization of growth media and hyperproduction of Laccase, LiP and MnP by Pleurotus ostreatus IBL-02, Ganoderma lucidum IBL-05 and Coriolus versicolor IBL-04, respectively using wheat straw for the production of laccase and  LiP and corn cobs for MnP production, respectively in SSF.