Isolation and characterization of a new cold-active protease from psychrotrophic bacteria of Western Himalayan glacial soil

Sci Rep. 2021 Jun 17;11(1):12768. doi: 10.1038/s41598-021-92197-w.

Abstract

As an approach to the exploration of cold-active enzymes, in this study, we isolated a cold-active protease produced by psychrotrophic bacteria from glacial soils of Thajwas Glacier, Himalayas. The isolated strain BO1, identified as Bacillus pumilus, grew well within a temperature range of 4-30 °C. After its qualitative and quantitative screening, the cold-active protease (Apr-BO1) was purified. The Apr-BO1 had a molecular mass of 38 kDa and showed maximum (37.02 U/mg) specific activity at 20 °C, with casein as substrate. It was stable and active between the temperature range of 5-35 °C and pH 6.0-12.0, with an optimum temperature of 20 °C at pH 9.0. The Apr-BO1 had low Km value of 1.0 mg/ml and Vmax 10.0 µmol/ml/min. Moreover, it displayed better tolerance to organic solvents, surfactants, metal ions and reducing agents than most alkaline proteases. The results exhibited that it effectively removed the stains even in a cold wash and could be considered a decent detergent additive. Furthermore, through protein modelling, the structure of this protease was generated from template, subtilisin E of Bacillus subtilis (PDB ID: 3WHI), and different methods checked its quality. For the first time, this study reported the protein sequence for psychrotrophic Apr-BO1 and brought forth its novelty among other cold-active proteases.

MeSH terms

  • Amino Acid Sequence
  • Bacteria / enzymology*
  • Bacteria / isolation & purification
  • Caseins / metabolism
  • Catalytic Domain
  • Cold Temperature*
  • Enzyme Inhibitors / pharmacology
  • Enzyme Stability / drug effects
  • Hydrogen-Ion Concentration
  • Hydrolysis
  • Ice Cover / microbiology*
  • India
  • Ions
  • Kinetics
  • Metals / pharmacology
  • Models, Molecular
  • Molecular Weight
  • Oxidants / pharmacology
  • Peptide Hydrolases / chemistry
  • Peptide Hydrolases / genetics
  • Peptide Hydrolases / isolation & purification*
  • Phylogeny
  • Protein Domains
  • Soil Microbiology*
  • Solvents / pharmacology
  • Substrate Specificity / drug effects
  • Surface-Active Agents / pharmacology

Substances

  • Caseins
  • Enzyme Inhibitors
  • Ions
  • Metals
  • Oxidants
  • Solvents
  • Surface-Active Agents
  • Peptide Hydrolases