title: Potential of semiarid soil from Caatinga biome as a novel source for mining lignocellulose-degrading enzymes.
abstract: The litterfall is the major organic material deposited in soil of Brazilian Caatinga biome, thus providing the ideal conditions for plant biomass-degrading microorganisms to thrive. Herein, the phylogenetic composition and lignocellulose-degrading capacity have been explored for the first time from a fosmid library dataset of Caatinga soil by sequence-based screening. A complex bacterial community dominated by Proteobacteria and Actinobacteria was unraveled. SEED subsystems-based annotations revealed a broad range of genes assigned to carbohydrate and aromatic compounds metabolism, indicating microbial ability to utilize plant-derived material. CAZy-based annotation identified 7275 genes encoding 37 glycoside hydrolases (GHs) families related to hydrolysis of cellulose, hemicellulose, oligosaccharides and other lignin-modifying enzymes. Taxonomic affiliation of genes showed high genetic potential of the phylum Acidobacteria for hemicellulose degradation, whereas Actinobacteria members appear to play an important role in celullose hydrolysis. Additionally, comparative analyses revealed greater GHs profile similarity among soils as compared to the digestive tract of animals capable of digesting plant biomass, particularly in the hemicellulases content. Combined results suggest a complex synergistic interaction of community members required for biomass degradation into fermentable sugars. This large repertoire of lignocellulolytic enzymes opens perspectives for mining potential candidates of biochemical catalysts for biofuels production from renewable resources and other environmental applications.
authors.affiliation: Research Center for Chemistry, Biology and Agriculture (CPQBA), UNICAMP, Division of Microbial Resources, Zip code 13148-218, Paulínia, São Paulo, Brazil gilenolacerdajr@gmail.com.
authors.forename: Gileno V
authors.initials: GV
authors.lastname: Lacerda Júnior
authors.affiliation: Research Center for Chemistry, Biology and Agriculture (CPQBA), UNICAMP, Division of Microbial Resources, Zip code 13148-218, Paulínia, São Paulo, Brazil.
authors.forename: Melline F
authors.initials: MF
authors.lastname: Noronha
authors.affiliation: Research Center for Chemistry, Biology and Agriculture (CPQBA), UNICAMP, Division of Microbial Resources, Zip code 13148-218, Paulínia, São Paulo, Brazil.
authors.forename: Sanderson Tarciso P
authors.initials: ST
authors.lastname: de Sousa
authors.affiliation: Research Center for Chemistry, Biology and Agriculture (CPQBA), UNICAMP, Division of Microbial Resources, Zip code 13148-218, Paulínia, São Paulo, Brazil.
authors.forename: Lucélia
authors.initials: L
authors.lastname: Cabral
authors.affiliation: Department of Bioengineering, University of California San Diego, La Jolla, CA 92093-0412, USA.
authors.forename: Daniela F
authors.initials: DF
authors.lastname: Domingos
authors.affiliation: Laboratory of Environmental Microbiology, Brazilian Agricultural Research Corporation, EMBRAPA Environment, Jaguariúna, Zip code 13820-000, Brazil.
authors.forename: Mírian L
authors.initials: ML
authors.lastname: Sáber
authors.affiliation: Laboratory of Environmental Microbiology, Brazilian Agricultural Research Corporation, EMBRAPA Environment, Jaguariúna, Zip code 13820-000, Brazil.
authors.forename: Itamar S
authors.initials: IS
authors.lastname: de Melo
authors.affiliation: Research Center for Chemistry, Biology and Agriculture (CPQBA), UNICAMP, Division of Microbial Resources, Zip code 13148-218, Paulínia, São Paulo, Brazil.
authors.forename: Valéria M
authors.initials: VM
authors.lastname: Oliveira
mesh_terms: D039903:Actinobacteria / Q000378:metabolism; D000818:Animals; D056804:Biofuels; D018533:Biomass; D001938:Brazil; D002482:Cellulose / Q000378:metabolism; D006026:Glycoside Hydrolases; D006868:Hydrolysis; D008031:Lignin / Q000378:metabolism*; D064307:Microbiota; D010802:Phylogeny; D020560:Proteobacteria / Q000378:metabolism; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology
chemical_list: D056804:Biofuels; D012987:Soil; C036909:lignocellulose; D002482:Cellulose; D008031:Lignin; D006026:Glycoside Hydrolases; C023305:hemicellulase
keywords: Caatinga soil; biofuels; bioinformatics; lignocellulose degradation; metagenomics/community genomics