Production of Cellulase and Amylase Enzymes in both Solid and Liquid States by Two Species of Fungi

Abstract

Aims: To isolate fungi capable of simultaneous production of amylase and cellulase
 Study Design: The experiment was carried out in aseptic conditions, data were subjected to one way Analysis of Variance (ANOVA) and the means were separated using Least Significance Deference (LSD).
 Place and Duration of Study: Department of Microbiology, University of Nigeria, Nsukka, Enugu State, Nigeria, between August 2010 and July 2013.
 Methodology: Plantain peels and infected bark of the stump of a tree were collected for fungi isolation. A 1 g sample each was weighed separately and added to 10 ml distilled water, 1 ml of each of the diluents was plated out on Emerson’s yeast phosphate soluble starch (YPSs) medium. After growth, colonies were picked and subcultured several times for purity. The isolates were characterized and identified based on colony morphology and microscopic examination. They were later screened for amylase and cellulase activities by growing them on various concentrations of starch and carboxymethyl cellulose
 Results: Amylolytic and cellulosic fungi were isolated from plantain peels and infected bark of a tree. The isolates were identified as Rhizopus and Fusarium sp and they were able to produce amylase and cellulase simultaneously. The enzyme activities were determined on various concentrations of starch and carboxymethyl cellulose (CMC) in liquid medium. At 2 % starch + 0 % CMC, enzymes activities were 127.44 U/ml and 144.59 U/ml glucoamylase and 356.43 U/ml and 263.63 U/ml cellulase for Rhizopus and Fusarium sp respectively. When the organisms were grown on a solid medium (koji) supplemented with various concentrations of CMC, there was an increase in cellulase activities as CMC increased. Cellulase activity of 1902.02 U/g was recorded by Rhizopus sp at 1.5 g CMC supplementation and 1481.18 U/g was from Fusarium sp at 1 g CMC supplementation, but highest glucoamylase activities of 322.68 U/g and 302.12 U/g were recorded for Rhizopus and Fusarium spp respectively at 1 g CMC supplementation. Glucoamylase activities were not significantly affected by CMC supplementation in solid state culture.
 Conclusion: The result of the study showed that the isolates were able to produce amylase and cellulase enzymes in appreciable quantities and therefore can find usefulness in industrial application of these enzymes.