Hydrogen Peroxide-Resistant CotA and YjqC of Bacillus altitudinis Spores Are a Promising Biocatalyst for Catalyzing Reduction of Sinapic Acid and Sinapine in Rapeseed Meal

PLoS One. 2016 Jun 30;11(6):e0158351. doi: 10.1371/journal.pone.0158351. eCollection 2016.

Abstract

For the more efficient detoxification of phenolic compounds, a promising avenue would be to develop a multi-enzyme biocatalyst comprising peroxidase, laccase and other oxidases. However, the development of this multi-enzyme biocatalyst is limited by the vulnerability of fungal laccases and peroxidases to hydrogen peroxide (H2O2)-induced inactivation. Therefore, H2O2-resistant peroxidase and laccase should be exploited. In this study, H2O2-stable CotA and YjqC were isolated from the outer coat of Bacillus altitudinis SYBC hb4 spores. In addition to the thermal and alkali stability of catalytic activity, CotA also exhibited a much higher H2O2 tolerance than fungal laccases from Trametes versicolor and Trametes trogii. YjqC is a sporulation-related manganese (Mn) catalase with striking peroxidase activity for sinapic acid (SA) and sinapine (SNP). In contrast to the typical heme-containing peroxidases, the peroxidase activity of YjqC was also highly resistant to inhibition by H2O2 and heat. CotA could also catalyze the oxidation of SA and SNP. CotA had a much higher affinity for SA than B. subtilis CotA. CotA and YjqC rendered from B. altitudinis spores had promising laccase and peroxidase activities for SA and SNP. Specifically, the B. altitudinis spores could be regarded as a multi-enzyme biocatalyst composed of CotA and YjqC. The B. altitudinis spores were efficient for catalyzing the degradation of SA and SNP in rapeseed meal. Moreover, efficiency of the spore-catalyzed degradation of SA and SNP was greatly improved by the presence of 15 mM H2O2. This effect was largely attributed to synergistic biocatalysis of the H2O2-resistant CotA and YjqC toward SA and SNP.

MeSH terms

  • Bacillus / enzymology*
  • Bacillus / genetics
  • Bacillus / metabolism
  • Bacterial Outer Membrane Proteins / physiology
  • Biocatalysis*
  • Bioreactors / microbiology
  • Brassica rapa / metabolism*
  • Catalase / genetics
  • Catalase / physiology*
  • Catalysis
  • Choline / analogs & derivatives*
  • Choline / metabolism
  • Coumaric Acids / metabolism*
  • Drug Resistance, Bacterial / genetics
  • Hydrogen Peroxide / pharmacology
  • Laccase / genetics
  • Laccase / physiology*
  • Oxidation-Reduction
  • Spores, Bacterial / chemistry
  • Spores, Bacterial / metabolism

Substances

  • Bacterial Outer Membrane Proteins
  • Coumaric Acids
  • sinapine
  • sinapinic acid
  • Hydrogen Peroxide
  • Laccase
  • Catalase
  • Choline

Grants and funding

This work was supported by the Fundamental Research Funds for the Central Universities. The research was funded by Collaborative Innovation Involving Production, Teaching & Research funds of Jiangsu Province (BY2014023-28) and Agricultural Support Project, Wuxi Science & Technology Development (CLE01N1310). This work was also financially supported by the Program of Marine Biological Resources Exploitation and Utilization of Science and Technology Innovation Team of Taizhou (No.1302ky08).