Identification and Characterization of a Novel Thermophilic, Organic Solvent Stable Lipase of Bacillus from a Hot Spring

Lipids. 2017 Jul;52(7):619-627. doi: 10.1007/s11745-017-4265-y. Epub 2017 Jun 3.

Abstract

A novel lipase gene lip256 was cloned and identified from the genomic library of hot spring strain Bacillus sp. HT19. The deduced amino acid sequence of lip256 has less than 32% identity to a predicted esterase (Cog1752) from Photobacterium leiognathi lrivu.4.1 and contains a novel motif (GTSAG) that differs from other clusters in the lipase superfamily. Following purification, a single band was obtained with a molecular mass of 33 kDa by SDS-PAGE, and the optimal temperature and pH for lipolytic activity of Lip25 were 70 °C and 9.0, respectively. Lip256 exhibited high activity at high temperatures, with 40% maximum activity at 80 °C and good stability at temperatures ranges between 50 and 80 °C. Additionally, the enzyme was highly stable in the presence of butyl-alcohol, glycerol, acetonitrile, pyridine, and urea. However, the presence of acetone, methanol, trichloromethane, petroleum ether, hexane, tert-butanol, isopropanol, dithiothreitol, ethylenediaminetetraacetic acid, polyhexamethylene biguanide, dimethyl sulfoxide, benzene, Triton X-100, Tween-20, Tween-80, and sodium dodecyl sulfate suppressed or absolutely inhibited enzyme activity. Furthermore, Ca2+, Mg2+, and Cu2+ suppressed enzyme activity, whereas Na+, Fe3+, K+, Fe2+, and Sr2+ enhanced enzyme activity. The unique characteristics of novel lipase Lip256, including its thermo-alkaliphilic performance, high tolerance toward metal ions, inhibitors, and detergents, and high stability in organic solvents, implied that this enzyme might be an interesting candidate for industrial processes.

Keywords: Bacillus sp.; Characterization; Identification; Lipase; Thermophile.

MeSH terms

  • Amino Acid Sequence
  • Bacillus / enzymology
  • Bacillus / genetics
  • Bacillus / isolation & purification*
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Cloning, Molecular
  • Genomic Library
  • Hot Springs / microbiology*
  • Hot Temperature
  • Hydrogen-Ion Concentration
  • Lipase / chemistry
  • Lipase / genetics*
  • Lipase / metabolism*
  • Molecular Weight
  • Protein Stability
  • Water Microbiology

Substances

  • Bacterial Proteins
  • Lipase