Destructuring plant biomass: Focus on fungal and extremophilic cell wall hydrolases. (May 2015)

• Record Type: Journal Article
• Authors: Guerriero, Gea; Hausman, Jean-Francois; Strauss, Joseph; Ertan, Haluk; Siddiqui, Khawar Sohail
• Is Part Of: Plant science. Volume 234(2015:May)
• Page Start: 180
• Page End: 193
• Publication Date: 2015-05
• Subjects: NBUS natural biomass utilization systems -- CWDEs cell wall degrading enzymes; Lignocellulosic biomass -- Saccharification -- Carbohydrate-active enzymes -- Fungal secretome -- Extremozymes -- Synergistic activation; Botany -- Periodicals; Botanique -- Périodiques; 580
• DOI: 10.1016/j.plantsci.2015.02.010
• Languages: English
• ISSNs: 0168-9452

Abstract

Graphical abstract: Highlights: Lignocellulose is an abundant renewable alternative to fossil fuels. Lignocellulose is recalcitrant to degradation by cell wall hydrolases. Fungi degrade plant biomass synergistically through secreted enzymes. Extremozymes help improve biomass conversion under harsh conditions. Strategies to improve function-stability and recycling of enzymes are discussed. Abstract: The use of plant biomass as feedstock for biomaterial and biofuel production is relevant in the current bio-based economy scenario of valorizing renewable resources. Fungi, which degrade complex and recalcitrant plant polymers, secrete different enzymes that hydrolyze plant cell wall polysaccharides. The present review discusses the current research trends on fungal, as well as extremophilic cell wall hydrolases that can withstand extreme physico-chemical conditions required in efficient industrial processes. Secretomes of fungi from the phyla Ascomycota, Basidiomycota, Zygomycota and Neocallimastigomycota are presented along with metabolic cues (nutrient sensing, coordination of carbon and nitrogen metabolism) affecting their composition. We conclude the review by suggesting further research avenues focused on the one hand on a comprehensive analysis of the physiology and epigenetics underlying cell wall degrading enzyme production in fungi and on the other hand on the analysis of proteins with unknown function and metagenomics of extremophilic consortia. The current advances in consolidated bioprocessing, altered secretory pathways and creation of designer plants are also examined. Furthermore, recent developments in enhancing the activity, stability and reusability of enzymes based on synergistic, proximity and entropic effects, fusion enzymes, structure-guided recombination between homologous enzymes and magnetic enzymes are considered with a view to improving saccharification.