title: Isolation and characterization of a non-specific endoglucanase from a metagenomic library of goat rumen.
abstract: A cellulase gene (cel28a) was isolated from a rumen microbial metagenome library of goat rumen microorganisms, cloned into E. coli, and expressed in active form. The gene has a length of 1596 bp obtained using a genome walking Kit and encodes a protein of 509 amino acids with a calculated MW of 55 kDa. The deduced amino acid sequence was homologous with cellulases belonging to the glycosyl hydrolase family 5 (GH5). The expressed protein showed activity toward carboxymethylcellulose (CMC) and xylan, suggesting non-specific endoglucanase activity. The optimal conditions for endoglucanase and xylanase activities were 50 °C and pH 5.0. The metal ions (Ca(2+), Fe(2+), Mn(2+) and Co(2+)) stimulated the cellulase activity of cel28a, while the other metal ions and chemicals (Ni(2+), Mg(2+), Zn(2+), Cu(2+), SDS and EDTA) inhibited the cellulase activity. Further examination of substrate preference showed a higher activity with CMC, oat spelt xylan and birchwood xylan than with filter paper and microcrystalline cellulose, again suggesting that the protein was an endoglucanase with xylanase activity.
authors.affiliation: College of Animal Science and Technology, Anhui Agricultural University, No. 130 Changjiang West Road, Hefei, 230036, Anhui, People's Republic of China. chengjianbofcy@163.com.
authors.forename: Jianbo
authors.initials: J
authors.lastname: Cheng
authors.affiliation: College of Animal Science and Technology, Anhui Agricultural University, No. 130 Changjiang West Road, Hefei, 230036, Anhui, People's Republic of China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Huang
authors.affiliation: College of Animal Science and Technology, Anhui Agricultural University, No. 130 Changjiang West Road, Hefei, 230036, Anhui, People's Republic of China.
authors.forename: Haiqin
authors.initials: H
authors.lastname: Jiang
authors.affiliation: College of Animal Science and Technology, Anhui Agricultural University, No. 130 Changjiang West Road, Hefei, 230036, Anhui, People's Republic of China.|Anhui Provincial Laboratory for Local Livestock & Poultry Genetic Resource Conservation and Bio-Breeding, No. 130 Changjiang West Road, Hefei, 230036, Anhui, People's Republic of China.
authors.forename: Yunhai
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: College of Animal Science and Technology, Anhui Agricultural University, No. 130 Changjiang West Road, Hefei, 230036, Anhui, People's Republic of China.
authors.forename: Lvmu
authors.initials: L
authors.lastname: Li
authors.affiliation: College of Animal Science and Technology, Anhui Agricultural University, No. 130 Changjiang West Road, Hefei, 230036, Anhui, People's Republic of China.
authors.forename: Juhua
authors.initials: J
authors.lastname: Wang
authors.affiliation: College of Animal Science and Technology, Anhui Agricultural University, No. 130 Changjiang West Road, Hefei, 230036, Anhui, People's Republic of China. fancaiyun@ahau.edu.cn.|Anhui Provincial Laboratory for Local Livestock & Poultry Genetic Resource Conservation and Bio-Breeding, No. 130 Changjiang West Road, Hefei, 230036, Anhui, People's Republic of China. fancaiyun@ahau.edu.cn.
authors.forename: Caiyun
authors.initials: C
authors.lastname: Fan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D002266:Carboxymethylcellulose Sodium / Q000378:metabolism; D002480:Cellulase / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism; D003001:Cloning, Molecular; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics; D006041:Goats / Q000382:microbiology*; D006863:Hydrogen-Ion Concentration; D056186:Metagenomics; D008969:Molecular Sequence Data; D010802:Phylogeny; D012417:Rumen / Q000382:microbiology*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D013379:Substrate Specificity; D014990:Xylans / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D014990:Xylans; D002482:Cellulose; D002480:Cellulase; D002266:Carboxymethylcellulose Sodium; C109691:microcrystalline cellulose
keywords: Endoglucanase; Goat rumen; Metagenome; Xylanase