Molecular characterization of Lactobacillus plantarum DMDL 9010, a strain with efficient nitrite degradation capacity

PLoS One. 2014 Nov 25;9(11):e113792. doi: 10.1371/journal.pone.0113792. eCollection 2014.

Abstract

Nitrites commonly found in food, especially in fermented vegetables, are potential carcinogens. Therefore, limiting nitrites in food is critically important for food safety. A Lactobacillus strain (Lactobacillus sp. DMDL 9010) was previously isolated from fermented vegetables by our group, and is not yet fully characterized. A number of phenotypical and genotypical approaches were employed to characterize Lactobacillus sp. DMDL 9010. Its nitrite degradation capacity was compared with four other Lactobacillus strains, including Lactobacillus casei subsp. rhamnosus 719, Lactobacillus delbrueckii subsp. bulgaricu 1.83, Streptococcus thermophilus 1.204, and lactobacillus plantarum 8140, on MRS medium. Compared to these four Lactobacillus strains, Lactobacillus sp. DMDL 9010 had a significantly higher nitrite degradation capacity (P<0.001). Based on 16S rDNA sequencing and sequence comparison, Lactobacillus sp. DMDL 9010 was identified as either Lactobacillus plantarum or Lactobacillus pentosus. To further identify this strain, the flanking regions (922 bp and 806 bp upstream and downstream, respectively) of the L-lactate dehydrogenase 1 (L-ldh1) gene were amplified and sequenced. Lactobacillus sp. DMDL 9010 had 98.92 and 76.98% sequence identity in the upstream region with L. plantarum WCFS1 and L. pentosus IG1, respectively, suggesting that Lactobacillu sp. DMDL 9010 is an L. plantarum strain. It was therefore named L. plantarum DMDL 9010. Our study provides a platform for genetic engineering of L. plantarum DMDL 9010, in order to further improve its nitrite degradation capacity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • DNA, Ribosomal / genetics
  • Genes, Bacterial
  • Lactobacillus plantarum / genetics*
  • Lactobacillus plantarum / metabolism
  • Molecular Sequence Data
  • Nitrites / metabolism*
  • Phylogeny
  • RNA, Ribosomal, 16S / genetics

Substances

  • DNA, Ribosomal
  • Nitrites
  • RNA, Ribosomal, 16S

Associated data

  • GENBANK/KJ917253
  • GENBANK/KM017408
  • GENBANK/KM017409

Grants and funding

This study was financially supported by the National Natural Science Foundation of China (No. 31101254), the Natural Science Foundation of the Guangdong Province (No. S2011010005679), and the Foundation of SCUT (D2116760). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.