A novel cold active esterase derived from Colombian high Andean forest soil metagenome

World J Microbiol Biotechnol. 2012 Jan;28(1):361-70. doi: 10.1007/s11274-011-0828-x. Epub 2011 Jul 1.

Abstract

In order to search new lipolytic enzymes and conduct bioprospecting of microbial communities from high Andean forest soil, a metagenomic library of approximately 20,000 clones was constructed in Escherichia coli using plasmid p-Bluescript II SK+. The library covered 80 Mb of the metagenomic DNA mainly from Proteobacteria, Actinobacteria and Acidobacteria. Two clones with lipolytic activity in tributyrin as a substrate were recovered. Clone BAA3G2 (pSK-estGX1) was selected and the entire 4.6 Kb insert sequence was determined. The sequence had a GC content of 70.6% and could be derived from an undescribed Actinobacteria genome. One open reading frame encoded a polypeptide of 210 amino acids (gene estGX1) with a molecular mass of 22.4 kDa that contained the pentapeptide G-P-S-G-G near the N-terminus essential for lipase activity and the putative catalytic triad was identified, also a putative ribosomal binding site located 18 bp upstream the estGX1 ATG start codon was identified. The phylogenetic analysis suggested that the protein belonged to a new lipase family. The secreted enzyme showed a preference for short length fatty acids, with specific activity against p-nitrophenyl-butyrate (0.142 U/mg of total protein), it was cold active with relative activity of 30% at 10°C and moderately thermo active with relative activity of 80% at 50°C and had a pH optimum of 8.0 at 40°C.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acinetobacter / enzymology
  • Acinetobacter / genetics
  • Acinetobacter / isolation & purification
  • Altitude
  • Amino Acid Sequence
  • Bacterial Proteins / genetics
  • Bacterial Proteins / isolation & purification
  • Bacterial Proteins / metabolism*
  • Cold Temperature
  • Colombia
  • Conserved Sequence
  • DNA, Bacterial / genetics
  • Esterases / genetics
  • Esterases / isolation & purification
  • Esterases / metabolism*
  • Genomic Library
  • Kinetics
  • Lipase / genetics
  • Lipase / isolation & purification
  • Lipase / metabolism
  • Metagenome
  • Molecular Sequence Data
  • Phylogeny
  • Sequence Homology, Amino Acid
  • Soil Microbiology*
  • Trees

Substances

  • Bacterial Proteins
  • DNA, Bacterial
  • Esterases
  • Lipase