Purification and characterization of pedioxanthin (carotenoid pigment) produced by Pediococcus pentosaceus N33 strain isolated from pickles

ABSTRACT

Forty-two lactic acid bacteria were isolated from 28 pickles and yoghurt samples, and screened for their antimicrobial efficacy against certain multidrug resistant (MDR) bacteria using well diffusion method. A strain Pediococcus pentosaceus N33 (MF062087) showed the best inhibitory effects against both Brevibacillus brevis H18 (MG637284) and Lysinibacillus fusiformis R29 (MG637285). Pediococcus pentosaceus N33 strain produced high thermostable antimicrobial compound as indicated by heat treatment between 60 and 100°C for 20 min as well as at 121°C for 15 min. It is a proteinaceous compound highly active at acidic pH (2–6). The antimicrobial compound was extracted and precipitated by 70% ammonium sulfate and finally fractionated using Sephadex G₅₀ column. The molecular weight of pure compound was 10 kDa using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis. The spectroscopic analysis based on UV, IR, NMR and MS analyses were used to characterize and identify the pure antimicrobial compound. From the characterization and identification of this inhibitory compound, it was observed that the target compound contains carotenoid pigment in addition to protein. This carotenoid pigment was identified as pedioxanthin which is the first observed from this strain. Our results evaluated the potential activity of Pediococcus pentosaceus N33 strain as a probiotic agent and its potential contribution for food industry and pharmaceutical applications.

KEYWORDS:

• Antimicrobial activity
• carotenoprotein
• lactic acid bacteria
• spectroscopic analysis
• pedioxanthin

Acknowledgments

We thank Prof. Dr. Wesam A. Hassanein for her revision of this study and we would like to thank Prof. Dr. M. G. Assy for identifying of the extracted compound.

Conflict of interest

The authors declare that they have no conflict of interest.

Supplementary material

Supplemental data for this article can be accessed here.