Genome sequencing and functional characterization of a Dictyopanus pusillus fungal enzymatic extract offers a promising alternative for lignocellulose pretreatment of oil palm residues

Abstract

The pretreatment of biomass remains a critical requirement for bio-renewable fuel production from lignocellulose. Although current processes primarily involve chemical and physical approaches, the biological breakdown of lignin using enzymes and microorganisms is quickly becoming an interesting eco-friendly alternative to classical processes. As a result, bioprospection of wild fungi from naturally occurring lignin-rich sources remains a suitable method to uncover and isolate new species exhibiting ligninolytic activity. In this study, wild species of white rot fungi were collected from Colombian forests based on their natural wood decay ability and high capacity to secrete oxidoreductases with high affinity for phenolic polymers such as lignin. Based on high activity obtained from solid-state fermentation using a lignocellulose source from oil palm as matrix, we describe the isolation and wholegenome sequencing of Dictyopanus pusillus, a wild basidiomycete fungus exhibiting ABTS oxidation as an indication of laccase activity. Functional characterization of a crude enzymatic extract identified laccase activity as the main enzymatic contributor to fungal extracts, an observation supported by the identification of 13 putative genes encoding for homologous laccases in the genome. To the best of our knowledge, this represents the first report of an enzymatic extract exhibiting laccase activity in the Dictyopanus genera, offering means to exploit this species and its enzymes for the delignification process of lignocellulosic by-products from oil palm.

A Comparative Photographic Review on Higher Plants and Macro-Fungi: A Soil Restoration for Sustainable Production of Food and Energy

“…There are many species of mushrooms that have the ability to produce bioethanol, such as Pleurotus florida, P. ostreatus, Ganoderma lucidum, Lentinula edodes, etc., as reported by Xiong et al [178], Rueda et al [182], Sudhakar et al [179], Devi et al [177], Periyasamy et al [181], and Ranjithkumar et al [180] (Table 5; Figure 13). The suggested mechanism of producing biofuels and energy from lignocellulosic biomass (LCB) is based on biochemical processes, which need certain conditions, especially C:N ratio < 30 and humidity >30% through biodegrading enzymes (e.g., laccase, mannanase, cellulase, and xylanase).…”

“…SMS of Ganoderma lucidum used by 0.2% (v/v) for fermentation using baker's yeast (Saccharomyces cerevisiae) and incubated for 5 days at 30 °C Fermentation using mushroom for bioethanol production I. Fermentation using Pleurotus florida on cotton spinning wastes and the optimum ethanol yield (1.18 g L −1 ) was obtained by 64% at 60 h II. Mushroom of Dictyopanus genera can its enzyme (laccase activity 267 U L −1 ) from oil palm delignification process for bioethanol derived-cellulose Sources: [99,172,173,[175][176][177][178][179][180][181][182].…”