1.Enhancement of cellulolytic enzymes and xylanase production via classical mutational techniques under solid-state fermentation condition
Tai Wan Yi ; Lee Chee Keong ; Darah Ibrahim2
Malaysian Journal of Microbiology 2016;12(1):91-101
Aims: High cost of cellulases remains the most significant barrier to the economical production of bio-ethanol from
lignocellulosic biomass (LB). The present study aims at developing a local cellulolytic fungal strain through random
mutagenesis coupled with the feasibility of solid-state fermentation (SSF) by utilizing agricultural wastes such as oil palm
frond (OPF) as the substrate.
Methodology and results: Out of 95 wild isolates tested, native fungal strain Aspergillus niger, designated DWA8 was
isolated as the top enzymatic secretor. For quantitative enzyme analysis, SSF was conducted using 1x106 spore/mL
inoculated onto 5 g of ground OPF, incubated at room temperature for 7 days, with 70% moisture content and an initial
medium pH of 7. Random mutagenesis has always been tempting in the enhancement of enzyme production. In this
work, the compounded treatment of microwave, ultraviolet (UVC) and Ethyl Methanesulfonate (EMS) have generated an
Aspergillus niger MUE3.06 mutant with an overall increase of 114% in CMCase activity, approximately 70% in FPase
and Xylanase activity respectively compared with the parental DWA8 strain. Thus this finding is capable to be fully
developed as an established mutational scheme to create highly productive filamentous fungus in a cheap, simple and
sustainable way.
Conclusion, significance and impact of study: It was the first attempt to explore the combine effect of the three
popular mutagens upon cellulases and xylanases. It is believed that more diversified of mutagen types induce more
diversified mutation pattern (with instructive planning), which is very desirable in creating new enzymes with novel
abilities.
Cellulases