Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Appl Environ Microbiol. 2008 Dec;74(23):7286-96. doi: 10.1128/AEM.00768-08. Epub 2008 Oct 10.

Synthesis and uptake of the compatible solutes ectoine and 5-hydroxyectoine by Streptomyces coelicolor A3(2) in response to salt and heat stresses.

Author information

  • 1Laboratory for Microbiology, Department of Biology, Philipps University Marburg, Marburg, Germany.

Abstract

Streptomyces coelicolor A3(2) synthesizes ectoine and 5-hydroxyectoine upon the imposition of either salt (0.5 M NaCl) or heat stress (39 degrees C). The cells produced the highest cellular levels of these compatible solutes when both stress conditions were simultaneously imposed. Protection against either severe salt (1.2 M NaCl) or heat stress (39 degrees C) or a combination of both environmental cues could be accomplished by adding low concentrations (1 mM) of either ectoine or 5-hydroxyectoine to S. coelicolor A3(2) cultures. The best salt and heat stress protection was observed when a mixture of ectoine and 5-hydroxyectoine (0.5 mM each) was provided to the growth medium. Transport assays with radiolabeled ectoine demonstrated that uptake was triggered by either salt or heat stress. The most effective transport and accumulation of [(14)C]ectoine by S. coelicolor A3(2) were achieved when both environmental cues were simultaneously applied. Our results demonstrate that the accumulation of the compatible solutes ectoine and 5-hydroxyectoine allows S. coelicolor A3(2) to fend off the detrimental effects of both high salinity and high temperature on cell physiology. We also characterized the enzyme (EctD) required for the synthesis of 5-hydroxyectoine from ectoine, a hydroxylase of the superfamily of the non-heme-containing iron(II)- and 2-oxoglutarate-dependent dioxygenases (EC 1.14.11). The gene cluster (ectABCD) encoding the enzymes for ectoine and 5-hydroxyectoine biosynthesis can be found in the genome of S. coelicolor A3(2), Streptomyces avermitilis, Streptomyces griseus, Streptomyces scabiei, and Streptomyces chrysomallus, suggesting that these compatible solutes play an important role as stress protectants in the genus Streptomyces.

PMID:
18849444
[PubMed - indexed for MEDLINE]
PMCID:
PMC2592907
Free PMC Article

Images from this publication.See all images (6)Free text

FIG. 1.
FIG. 2.
FIG. 3.
FIG. 4.
FIG. 5.
FIG. 6.
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk