Isolation and characterization of a novel glycosyl hydrolase family 74 (GH74) cellulase from the black goat rumen metagenomic library

Folia Microbiol (Praha). 2017 May;62(3):175-181. doi: 10.1007/s12223-016-0486-3. Epub 2016 Nov 19.

Abstract

This study aimed to isolate and characterize a novel cellulolytic enzyme from black goat rumen by using a culture-independent approach. A metagenomic fosmid library was constructed from black goat rumen contents and screened for a novel cellulase. The KG37 gene encoding a protein of 858 amino acid residues (92.7 kDa) was isolated. The deduced protein contained a glycosyl hydrolase family 74 (GH74) domain and showed 77% sequence identity to two endo-1,4-β-glucanases from Fibrobacter succinogenes. The novel GH74 cellulase gene was overexpressed in Escherichia coli, and its protein product was functionally characterized. The recombinant GH74 cellulase showed a broad substrate spectrum. The enzyme exhibited its optimum activity at pH 5.0 and temperature range of 20-50 °C. The enzyme was thermally stable at pH 5.0 and at a temperature of 20-40 °C. The novel GH74 cellulase can be practically exploited to convert lignocellulosic biomass to value-added products in various industrial applications in future.

MeSH terms

  • Animals
  • Cellulase / chemistry
  • Cellulase / genetics*
  • Cellulase / isolation & purification*
  • Cloning, Molecular
  • Enzyme Stability
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Fibrobacter / enzymology
  • Fibrobacter / genetics
  • Gene Expression
  • Gene Library
  • Genetic Testing
  • Goats / microbiology*
  • Hydrogen-Ion Concentration
  • Metagenome*
  • Metagenomics
  • Molecular Weight
  • Recombinant Proteins / genetics
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism
  • Rumen / microbiology*
  • Sequence Homology
  • Substrate Specificity
  • Temperature

Substances

  • Recombinant Proteins
  • Cellulase