Comprehensive studies on optimization of cellulase and xylanase production by a local indigenous fungus strain via solid state fermentation using oil palm frond as substrate

Abstract

The high cost of cellulases remains the most significant barrier to the economical production of bio-ethanol from lignocellulosic biomass. The goal of this study was to optimize cellulases and xylanase production by a local indigenous fungus strain (Aspergillus niger DWA8) using agricultural waste (oil palm frond [OPF]) as substrate.The enzyme production profile before optimization indicated that the highest carboxymethyl cellulose (CMCase), filter paper (FPase), and xylanase activities of 1.06 U/g, 2.55 U/g, and 2.93 U/g were obtained on day 5, day 4, and day 5 of fermentation, respectively. Response surface methodology was used to study the effects of several key process parameters in order to optimize cellulase production. Of the five physical and two chemical factors tested, only moisture content of 75% (w/w) and substrate amount of 2.5 g had statistically significant effect on enzymes production. Under optimized conditions of 2.5 g of substrate, 75% (w/w) moisture content, initial medium of pH 4.5, 1 × 10 6 spores/mL of inoculum, and incubation at ambient temperature (±30 C) without additional carbon and nitrogen, the highest CMCase, FPase, and xylanase activities obtained were 2.38 U/g, 2.47 U/g, and 5.23 U/g, respectively. Thus, the optimization process increased CMCase and xylanase production by 124.5 and 78.5%, respectively. Moreover, A. niger DWA8 produced reasonably good cellulase and xylanase titers using OPF as the substrate when compared with previous researcher finding. The enzymes produced by this process could be further use to hydrolyze biomass to generate reducing sugars, which are the feedstock for bioethanol production. K E Y W O R D SAspergillus niger, cellulases, oil palm frond, response surface methodology, xylanase

A detailed overview of xylanases: an emerging biomolecule for current and future prospective

“…Similarly, Tai et al (2019) reported the optimization of five physical and two nutritional parameters using the RSM approach for enhanced xylanase production. Indigenous fungus Aspergillus niger DWA8 was grown under SSF on an oil palm frond.…”

Optimization of β-1,4-Endoxylanase Production by an Aspergillus niger Strain Growing on Wheat Straw and Application in Xylooligosaccharides Production

“…Behnam et al [ 48 ] reported that the interaction between moisture and incubation time was significant for xylanase production by Mucor indicus and were non-significant for Mucor hiemalis and R. oryzae xylanase through SSF on wheat bran. In this sense, Tai et al [ 20 ], reported significant interaction between xylanase production and moisture level when A. niger DWA8 was grown using agricultural waste. According to studies conducted by Almeida et al and Azzouz et al [ 24 , 49 , 50 ], the interaction between the moisture level and incubation time does not significantly affect biomass and xylanase production by Penicillium roqueforti ATCC 10110, Trichoderma afroharzianum , and A. niger BG during solid-state fermentation of yellow mombin residue and wheat bran, respectively.…”

“…RSM modeling strategies have been used for improving xylanase production by Aspergillus candidus [ 52 ] and A. fumigatus ABK9 [ 53 ] with wheat straw as the substrate, as well as other Aspergillus strains growing on related substrates [ 20 , 21 ]. Therefore, it may be concluded that BBD-based RSM strategies can significantly enhance xylanase production.…”

“…Specially, Aspergillus and Trichoderma species have been studied extensively for their ability to secrete high-levels of enzymes in solid-state fermentation (SSF) [ 12 , 13 , 14 , 15 , 16 ]. Aspergillus is a genus usually employed to produce xylanolytic enzyme cocktails in industrial plants for applications like paper manufacturing, bread-making, animal feed, juice and wine industries [ 17 , 18 ] and, thus, several studies reporting enzymatic production optimization have been released, either by traditional One-Factor-at-a-Time (OFAT) approach [ 19 ] or by Response Surface Methodology (RSM) [ 20 , 21 ]. However, since the enzymatic system secreted by fungi depends on the strain and the culture conditions, it is interesting to study new isolates to produce efficient and robust enzymes.…”

The impact of Egyptian thermophylic cellulase on the dyeability of natural and recovered cellulosic fabrics

“…Generally, the production of cellulases is very expressive owing to their various biotechnological applications. However their high cost, low titer of their production and low thermal stability of the produced enzymes remain the most significant barriers to their industrial applications [14][15][16]. therefore, microbial production of cellulase on local agriculture wastes represents a promising future for industrial applications with high environmental impact.…”