title: Destructuring plant biomass: focus on fungal and extremophilic cell wall hydrolases.
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.
authors: Environmental Research and Innovation (ERIN), Luxembourg Institute of Science and Technology (LIST), Esch/Alzette, Luxembourg. Electronic address: gea.guerriero@list.lu.
authors: Gea
authors: G
authors: Guerriero
authors: Environmental Research and Innovation (ERIN), Luxembourg Institute of Science and Technology (LIST), Esch/Alzette, Luxembourg.
authors: Jean-Francois
authors: JF
authors: Hausman
authors: Department of Applied Genetics and Cell Biology, Fungal Genetics and Genomics Unit, University of Natural Resources and Life Sciences Vienna (BOKU), University and Research Center Campus Tulln-Technopol, Tulln/Donau, Austria; Health and Environment Department, Austrian Institute of Technology GmbH - AIT, University and Research Center Campus Tulln-Technopol, Tulln/Donau, Austria.
authors: Joseph
authors: J
authors: Strauss
authors: School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia; Department of Molecular Biology and Genetics, Istanbul University, Turkey.
authors: Haluk
authors: H
authors: Ertan
authors: Biology Department, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran, Saudi Arabia. Electronic address: ksiddiqui@kfupm.edu.sa.
authors: Khawar Sohail
authors: KS
authors: Siddiqui
mesh_terms: D001203:Ascomycota / Q000201:enzymology / Q000235:genetics; D001487:Basidiomycota / Q000201:enzymology / Q000235:genetics; D018533:Biomass; D002473:Cell Wall / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D005658:Fungi / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D006867:Hydrolases / Q000235:genetics / Q000378:metabolism*; D010944:Plants / Q000378:metabolism / Q000382:microbiology*
chemical_list: D005656:Fungal Proteins; D006867:Hydrolases
keywords: Carbohydrate-active enzymes; Extremozymes; Fungal secretome; Lignocellulosic biomass; Saccharification; Synergistic activation