Dynamics in Copy Numbers of Five Plasmids of a Dairy Lactococcus lactis Strain under Dairy-Related Conditions Including Near-Zero Growth Rates.

ABSTRACT: Lactic acid bacteria can carry multiple plasmids affecting their performance in dairy fermentations. The expression of plasmid-borne genes and the activity of the corresponding proteins are severely affected by changes in the numbers of plasmid copies. We studied the impact of growth rate on the dynamics of plasmid copy numbers at high growth rates in chemostat cultures and down to near-zero growth rates in retentostat cultures. Five plasmids of the dairy strain Lactococcus lactis FM03-V1 were selected, and these varied in size (3 to 39 kb), in replication mechanism (theta or rolling circle), and in putative (dairy-associated) functions. The copy numbers ranged from 1.5 to 40.5, and the copy number of theta-type replicating plasmids was negatively correlated to the plasmid size. Despite th

SUBMITTER: van Mastrigt O 

PROVIDER: S-EPMC5960958 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature