Citrate, low pH and amino acid limitation induce citrate utilization in Lactococcus lactis biovar diacetylactis.

ABSTRACT: In Lactococcus lactis subsp. lactis biovar diacetylactis, citrate transport is facilitated by the plasmid-encoded citrate permease (CitP). In this work, we analysed regulation of citrate utilization by pH, nutrient limitation and the presence of citrate at four different levels: (i) plasmid copy number, (ii) citP transcription, (iii) citP mRNA processing and (iv) citrate utilization capacity. Citrate was supplied as cosubstrate together with lactose. The citP gene is known to be induced in cells grown at low pH. However, we demonstrated that transcription of citP was even higher in the presence of citrate (3.8-fold compared with 2.0-fold). The effect of citrate has been overlooked by other researchers because they determined the effect of citrate using M17 medium, which already contains 0.

SUBMITTER: van Mastrigt O 

PROVIDER: S-EPMC5812246 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature