Expression of PprI from Deinococcus radiodurans Improves Lactic Acid Production and Stress Tolerance in Lactococcus lactis

PLoS One. 2015 Nov 12;10(11):e0142918. doi: 10.1371/journal.pone.0142918. eCollection 2015.

Abstract

PprI is a general switch protein that regulates the expression of certain proteins involved in pathways of cellular resistance in the extremophilic bacterium Deinococcus radiodurans. In this study, we transformed pprI into Lactococcus lactis strain MG1363 using the lactococcal shuttle vector pMG36e and investigated its effects on the tolerance and lactic acid production of L. lactis while under stress. PprI was stably expressed in L. lactis as confirmed by western blot assays. L. lactis expressing PprI exhibited significantly improved resistance to oxidative stress and high osmotic pressure. This enhanced cellular tolerance to stressors might be due to the regulation of resistance-related genes (e.g., recA, recO, sodA, and nah) by pprI. Moreover, transformed L. lactis demonstrated increased lactic acid production, attributed to enhanced lactate dehydrogenase activity. These results suggest that pprI can improve the tolerance of L. lactis to environmental stresses, and this transformed bacterial strain is a promising candidate for industrial applications of lactic acid production.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Deinococcus / genetics*
  • Gene Expression
  • Genetic Vectors / genetics
  • Industrial Microbiology
  • L-Lactate Dehydrogenase / metabolism
  • Lactic Acid / metabolism*
  • Lactococcus lactis / enzymology
  • Lactococcus lactis / genetics*
  • Lactococcus lactis / metabolism*
  • Osmotic Pressure
  • Oxidative Stress
  • Transformation, Genetic*

Substances

  • Bacterial Proteins
  • Lactic Acid
  • L-Lactate Dehydrogenase

Grants and funding

This work was supported by the Foundation of Henan Science and Technology Committee (grant No. 132300410123), the Exploration, Torch-plan Project (grant No. 112102310069) from Henan Province, the Special Fund for Agro-Scientific Research in the Public Interest of China (grant No. 201103007), and the National Natural Science Foundation of China (http://www.nsfc.gov.cn/; grant Nos. 11405147, 31170079, 31210103904, 31370119 and 31370102). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.