A single point mutation in the listerial betL sigma(A)-dependent promoter leads to improved osmo- and chill-tolerance and a morphological shift at elevated osmolarity

作者：Hoffmann Roland F; McLernon Susan; Feeney Audrey; Hill Colin; Sleator Roy D^*

来源：Bioengineered, 2013, 4(6): 401-407.

DOI：10.4161/bioe.24094

• Listeria
• osmotolerance
• chill-tolerance
• salt stress
• twisted cells

Betaine uptake in Listeria monocytogenes is mediated by three independent transport systems, the simplest of which in genetic terms is the secondary transporter BetL. Using a random mutagenesis approach, based on the E. coli XL1 Red mutator strain, we identified a single point mutation in a putative promoter region upstream of the BetL coding region which leads to a significant increase in betL transcript levels under osmo- and chill-stress conditions and a concomitant increase in stress tolerance. Furthermore, the mutation appears to counter the heretofore unreported %26quot;twisted%26quot; cell morphology observed for L. monocytogenes grown at elevated osmolarities in tryptone soy broth.

• 出版日期2013-12