Potential Uses of Xylanase-Rich Lignocellulolytic Enzymes Cocktail for Oil Palm Trunk (OPT) Degradation and Lignocellulosic Ethanol Production

Abstract

In this paper, we reported that oil pam trunk (OPT) can be used as an alternative fermentation feedstock for lignocellulolytic enzyme production and carbon source for bioethanol production. Xylanase production from OPT by locally isolated fungus, Aspergillus fumigatus SK1, under solid state fermentation (SSF) was optimized using central composite design (CCD). Under optimized conditions, a maximum xylanase activity of 1792.43 U/g was produced, which was 4.28 folds higher than before optimization. Significant amount of CMCase (56.19 U/g), FPase (3.47 U/g), and β-glucosidase (1.55 U/g) were also found concomitantly with xylanase. Subsequently, the effect of solid loading, Tween-80 concentration and incubation temperature on saccharification of OPT by the crude enzymes were optimized to enhance the total reducing sugar production. A total of 13.148 g/L of reducing sugar was reported at optimized condition. The comparisons of physiochemical characteristics between native and hydrolysed OPT by SEM, FTIR and XPS showed strong degradation capacity of the crude enzymes towards cellulose, hemicellulose and lignin.Alcoholic fermentation of the hydrolysate by Candida tropicalis RETL-Crl produced 3.067 g/L of ethanol. Higher ethanol production at 0.322 g/g with theoretical ethanol yield of 68.05%indicates Candida tropicalis RETL-Crl has a greater potential to be used in ethanol fermentation process. This result further proved that OPT has potential to be used as a renewable carbon source.

Upcycling the Spent Mushroom Substrate of the Grey Oyster Mushroom Pleurotus pulmonarius as a Source of Lignocellulolytic Enzymes for Palm Oil Mill Effluent Hydrolysis

“…released a total reducing sugar of 85.8%. In another study, the hydrolysis of oil palm trunk by crude enzymes from Aspergillus fumigatus released 13.15 g/l of reducing sugar [ 52 ]. The variations in the yield of reducing sugar were possibly contributed by the variety of chemical content in biomass and pretreatment conditions [ 53 ].…”

Potential application of waste from castor bean (Ricinus communis L.) for production for xylanase of interest in the industry

“…The lower xylanase production at higher moisture levels could attribute to alteration in particle structure, decrease in porosity or lower oxygen transfer, whereas the lower moisture content leads to a reduction in the diffusion of the nutrients and oxygen in the substrate, lower degree of swelling and higher water tension (Hasseltine 1972 ). On the other hand, Soliman et al ( 2012 ) related that 75 % was the optimum initial moisture for xylanase production by A. niger (21.32 U g −1 ) in using barley bran and Ang et al ( 2015 ) related that initial moisture of 75–80 % is optimal to xylanase production using Aspergillus fumigatus SK1 cultivated SSF with in oil palm trunk.…”

“…It has been shown in a previous study that A. tubingensis JP-1 was unable to produce a considerable xylanase yield above 30 °C (Pandya and Gupta 2012 ). On the other hand, Ang et al ( 2015 ) related that maximum xylanase production by Aspergillus fumigatus SK1 cultivated SSF with in oil palm trunk was between 40 and 45 °C and Adhyaru et al ( 2015 ) found the highest XY production of 1998 ± 12 U g ds −1 by Aspergillus tubingensis FDHN1 in sorghum straw SSF at 40 °C. It shows that the type of fermentable wastes and species of microorganisms may also affect the value of incubation temperature.…”

Solid-State Fermentation as a Novel Paradigm for Organic Waste Valorization: A Review

“…Du et al [181] confirmed the feasibility of scaling up the bioconversion of sweet sorghum stalks by S. cerevisiae from 500 mL to a 127 m 3 rotary drum fermenter and subsequently in a 550 m 3 rotary drum fermenter with 88% of relative theoretical ethanol yield in less than 20 h. Anjani et al [180] presented an interesting integrated bioconversion of potato peel by SSF for the production of bioethanol and manure by employing yeast and fungi (Aspergillus niger, A. variabilis and S. cerevisiae) in an effort to achieve zero waste generation. In Asian regions, palm oil trunk [184], rice straw [185,186], and banana pseudo stem [187] were successfully utilized to produce bioethanol with high yield (84%) by Aspergillus sp. and T. reesei through SSF.…”