title: Insights into plant biomass conversion from the genome of the anaerobic thermophilic bacterium Caldicellulosiruptor bescii DSM 6725.
abstract: Caldicellulosiruptor bescii DSM 6725 utilizes various polysaccharides and grows efficiently on untreated high-lignin grasses and hardwood at an optimum temperature of ∼ 80 °C. It is a promising anaerobic bacterium for studying high-temperature biomass conversion. Its genome contains 2666 protein-coding sequences organized into 1209 operons. Expression of 2196 genes (83%) was confirmed experimentally. At least 322 genes appear to have been obtained by lateral gene transfer (LGT). Putative functions were assigned to 364 conserved/hypothetical protein (C/HP) genes. The genome contains 171 and 88 genes related to carbohydrate transport and utilization, respectively. Growth on cellulose led to the up-regulation of 32 carbohydrate-active (CAZy), 61 sugar transport, 25 transcription factor and 234 C/HP genes. Some C/HPs were overproduced on cellulose or xylan, suggesting their involvement in polysaccharide conversion. A unique feature of the genome is enrichment with genes encoding multi-modular, multi-functional CAZy proteins organized into one large cluster, the products of which are proposed to act synergistically on different components of plant cell walls and to aid the ability of C. bescii to convert plant biomass. The high duplication of CAZy domains coupled with the ability to acquire foreign genes by LGT may have allowed the bacterium to rapidly adapt to changing plant biomass-rich environments.
authors.affiliation: Institute of Bioinformatics, Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA.
authors.forename: Phuongan
authors.initials: P
authors.lastname: Dam
authors.forename: Irina
authors.initials: I
authors.lastname: Kataeva
authors.forename: Sung-Jae
authors.initials: SJ
authors.lastname: Yang
authors.forename: Fengfeng
authors.initials: F
authors.lastname: Zhou
authors.forename: Yanbin
authors.initials: Y
authors.lastname: Yin
authors.forename: Wenchi
authors.initials: W
authors.lastname: Chou
authors.forename: Farris L
authors.initials: FL
authors.lastname: Poole
authors.forename: Janet
authors.initials: J
authors.lastname: Westpheling
authors.forename: Robert
authors.initials: R
authors.lastname: Hettich
authors.forename: Richard
authors.initials: R
authors.lastname: Giannone
authors.forename: Derrick L
authors.initials: DL
authors.lastname: Lewis
authors.forename: Robert
authors.initials: R
authors.lastname: Kelly
authors.forename: Harry J
authors.initials: HJ
authors.lastname: Gilbert
authors.forename: Bernard
authors.initials: B
authors.lastname: Henrissat
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
authors.forename: Michael W W
authors.initials: MW
authors.lastname: Adams
mesh_terms: D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics; D018533:Biomass; D050260:Carbohydrate Metabolism / Q000235:genetics*; D020869:Gene Expression Profiling; D005798:Genes, Bacterial; D016680:Genome, Bacterial; D023281:Genomics; D006094:Gram-Positive Bacteria / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D010944:Plants / Q000378:metabolism; D040901:Proteomics
chemical_list: D001426:Bacterial Proteins