Using Streptococcus thermophilus phages, plasmid transduction in Lactococcus lactis was demonstrated. The transduction frequencies were 4 orders of magnitude lower in L. lactis than in S. thermophilus. These results are the first evidence that there is phage-mediated direct transfer of DNA from S. thermophilus to L. lactis. The implications of these results for phage evolution are discussed.

Lactic acid bacteria have been isolated from living, harvested, and fermented plant materials; however, the adaptations these bacteria possess for growth on plant tissues are largely unknown. In this study, we investigated plant habitat-specific traits of Lactococcus lactis during growth in an Arabidopsis thaliana leaf tissue lysate (ATL). L. lactis KF147, a strain originally isolated from plan...

25 Lactococcus lactis is a prokaryotic microorganism with great importance as a starter 26 culture and has become the model species among the lactic acid bacteria. The long and 27 safe history of use of L. lactis in dairy fermentations has resulted in the classification of 28 this species as GRAS (General Regarded As Safe) or QPS (Qualified Presumption of 29 Safety). However, our group has iden...

Lactococcus lactis is a prokaryotic microorganism with great importance as a culture starter and has become the model species among the lactic acid bacteria. The long and safe history of use of L. lactis in dairy fermentations has resulted in the classification of this species as GRAS (General Regarded As Safe) or QPS (Qualified Presumption of Safety). However, our group has identified several ...

Lactobacillus delbrueckii represents a technologically relevant member of lactic acid bacteria, since the two subspecies bulgaricus and lactis are widely associated with fermented dairy products. In the present work, we report the characterization of two commercial strains belonging to L. delbrueckii subspecies bulgaricus, lactis and a novel strain previously isolated from a traditional ferment...

Whole-genome nucleotide sequencing has revolutionized the genetic, biochemical and molecular biology research on bacteria and indeed, many higher organisms. The genome sequences of the strains of two subspecies of Lactococcus lactis, L. lactis subsp. lactis and L. lactis subsp. cremoris, have been determined. These genomic sequences have permitted two important new approaches to be applied in t...

Two strains of Lactococcus lactis subsp. lactis were used to determine the influence of lactose and arginine on viability and amino acid use during carbohydrate starvation. Lactose provided energy for logarithmic-phase growth, and amino acids such as arginine provided energy after carbohydrate exhaustion. Survival time, cell numbers, and ATP concentrations increased with the addition of arginin...

Small heat shock proteins are protective produced by organisms under thermal stress. They widely present in living organisms. Here, Hsp18, Hsp18.55 and Hsp19.5 genes were cloned from Lactobacillus plantarum heterologous expressed Lactococcus lactis , their potential functions ethanol stress investigated. The results showed that the recombinant strain over expressing gene had stronger resistance...

Lactococcus lactis subsp. cremoris MG1363 is an important starter culture for dairy fermentation. During industrial fermentations, L. lactis is constantly exposed to stresses that affect the growth and performance of the bacterium. Although the response of L. lactis to several stresses has been described, the adaptation mechanisms at the level of in vivo fluxes have seldom been described. To ga...

The prsA-like gene from Lactococcus lactis encoding its single homologue to PrsA, an essential protein triggering the folding of secreted proteins in Bacillus subtilis, was characterized. This gene, annotated pmpA, encodes a lipoprotein of 309 residues whose expression is increased 7- to 10-fold when the source of nitrogen is limited. A slight increase in the expression of the PrsA-like protein...