Abstract Novel application of coconut husk as growth support matrix and natural inducer of fungal laccase production in a bubble column reactor

*Author for Correspondence.
Institute of Biological Sciences,
Faculty of Science, University of Malaya,
Kuala Lumpur 50603, Malaysia.
Tel: 6-03-7967-6740, Fax: 6-03-7967-4178,
E-mail: suffian_ This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract.
Laccase production by a white-rot fungus Pycnoporus sanguineus and its growth in a bubble column reactor were studied as a function of different inducers and superficial gas velocities. Free suspended biomass and immobilized biomass systems were studied where in the latter novel application of coconut husk as simultaneous support matrix and natural laccase inducer was studied. Good biomass growth was observed in the free suspension cultivation but no laccase activity was detected even after known enzyme inducers were applied. In the immobilized biomass system supplied with aeration at superficial gas velocity of 1.14 x 10^-3 m s^-1, the fungus growing on the surface of coconut husk produced significant amount of biomass at 2.4 ± 0.2 g L^-1 dry weight as compared to the non-aerated (control) system where only 0.6 ± 0.1 g L^-1 dry weight of biomass was obtained. Laccase activity was detected only after 36 hours of fermentation and the highest activity i.e. 2.85 ± 0.05 U L^-1 was obtained at 48 hours. No laccase activity was detected in the non-aerated system even after 48 hours of fermentation.