Assessment of β-D-glucosidase activity and bgl gene expression of Oenococcus oeni SD-2a

PLoS One. 2020 Oct 9;15(10):e0240484. doi: 10.1371/journal.pone.0240484. eCollection 2020.

Abstract

Glycosidases enhance flavor during wine-making by mediating the enzymatic release of aroma molecules. In order to better understand the aroma enhancement potential of Oenococcus oeni SD-2a, β-D-glucosidase (βG) activities in the culture supernatant, whole cells, and disrupted cell lysate were assessed at mid log, late log and stationary growth phase. The enzymatic activity was also compared further from cell cultures with 5 different carbon sources (glucose, cellobiose, arbutin, glucose and cellobiose, glucose and arbutin) at late log phase. Correspondingly, expression levels of 3 bgl genes, OEOE-0224, OEOE-1210, and OEOE-1569 were investigated from cell cultures of the 3 growth phases, and the 5 cell cultures with different carbon sources. Finally, the volatile aroma compounds released by O. oeni SD-2a in synthetic wines with natural glycosides were evaluated by GC-MS. Results showed βG of O. oeni SD-2a was not extracellular enzyme, and the location of it didn't change with the change of growth phase and carbon source studied. βG activities in the whole cells and disrupted cell lysate were similar and constant at the 3 growth phases. As for the carbon sources, βG activities of whole cells and disrupted lysate were positively affected by cellobiose. While arbutin displayed positive and negative effect on βG activity of whole cells and disrupted lysate, respectively. It is probably that bgl genes OEOE-0224 and OEOE-1210 were related to βG activity of SD-2a whole cells, while OEOE-1569 was responsible for βG activity of disrupted lysate. More kinds of volatile compounds and higher total concentration were released by SD-2a in synthetic wine compared with control. Thus, SD-2a showed a great potential for flavor enhancement under wine-like conditions. This study provides more information for further study of βG activity from O. oeni SD-2a.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Carbon / metabolism
  • Fermentation
  • Gas Chromatography-Mass Spectrometry
  • Gene Expression Regulation, Bacterial
  • Gene Expression Regulation, Enzymologic
  • Oenococcus / enzymology
  • Oenococcus / genetics
  • Oenococcus / growth & development*
  • Volatile Organic Compounds / analysis*
  • Wine / analysis
  • Wine / microbiology
  • beta-Glucosidase / genetics
  • beta-Glucosidase / metabolism*

Substances

  • Bacterial Proteins
  • Volatile Organic Compounds
  • Carbon
  • beta-Glucosidase

Supplementary concepts

  • Oenococcus oeni

Grants and funding

Author: Yahui Li Grant numbers: BK20170603 and 31901675 Names of funder: Natural Science Foundation of Jiangsu Province, China and National Natural Science Foundation of China. URL of funder website: http://std.jiangsu.gov.cn/http://www.nsfc.gov.cn/ The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.