Influence of low-shear modeled microgravity on heat resistance, membrane fatty acid composition, and heat stress-related gene expression in Escherichia coli O157: H7 ATCC 35150, ATCC 43889, ATCC 43890, and ATCC 43895

H. W. Kim, Min-Suk Rhee

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

We previously showed that modeled microgravity conditions alter the physiological characteristics of Escherichia coli O157:H7. To examine how microgravity conditions affect bacterial heat stress responses, D values, membrane fatty acid composition, and heat stress-related gene expression (clpB, dnaK, grpE, groES, htpG, htpX, ibpB, and rpoH), E. coli O157:H7 ATCC 35150, ATCC 43889, ATCC 43890, and ATCC 43895 were cultured under two different conditions: low-shear modeled microgravity (LSMMG, an analog of spaceflight conditions) and normal gravity (NG, Earth-like conditions). When 24-h cultures were heated to 55°C, cells cultured under LSMMG conditions showed reduced survival compared with cells cultured under NG conditions at all time points (P <0.05). D values of all tested strains were lower after LSMMG culture than after NG culture. Fourteen of 37 fatty acids examined were present in the bacterial membrane: nine saturated fatty acids (SFA) and five unsaturated fatty acids (USFA). The USFA/SFA ratio, a measure of membrane fluidity, was higher under LSMMG conditions than under NG conditions. Compared with control cells grown under NG conditions, cells cultured under LSMMG conditions showed downregulation of eight heat stress-related genes (average,-1.9-to-3.7-fold). The results of this study indicate that in a simulated space environment, heat resistance of E. coli O157:H7 decreased, and this might be due to the synergistic effects of the increases in membrane fluidity and downregulated relevant heat stress genes.

Original languageEnglish
Pages (from-to)2893-2901
Number of pages9
JournalApplied and Environmental Microbiology
Volume82
Issue number10
DOIs
Publication statusPublished - 2016 May 1

Fingerprint

microgravity
Weightlessness
Escherichia coli O157
heat tolerance
cultured cells
shear stress
gene expression
heat stress
membrane fluidity
Fatty Acids
fatty acid
Hot Temperature
fatty acid composition
membrane
Gene Expression
unsaturated fatty acids
Cultured Cells
Membrane Fluidity
saturated fatty acids
Membranes

ASJC Scopus subject areas

  • Applied Microbiology and Biotechnology
  • Food Science
  • Biotechnology
  • Ecology

Cite this

@article{462b0049ac424992b7ee4531b1c40b92,
title = "Influence of low-shear modeled microgravity on heat resistance, membrane fatty acid composition, and heat stress-related gene expression in Escherichia coli O157: H7 ATCC 35150, ATCC 43889, ATCC 43890, and ATCC 43895",
abstract = "We previously showed that modeled microgravity conditions alter the physiological characteristics of Escherichia coli O157:H7. To examine how microgravity conditions affect bacterial heat stress responses, D values, membrane fatty acid composition, and heat stress-related gene expression (clpB, dnaK, grpE, groES, htpG, htpX, ibpB, and rpoH), E. coli O157:H7 ATCC 35150, ATCC 43889, ATCC 43890, and ATCC 43895 were cultured under two different conditions: low-shear modeled microgravity (LSMMG, an analog of spaceflight conditions) and normal gravity (NG, Earth-like conditions). When 24-h cultures were heated to 55°C, cells cultured under LSMMG conditions showed reduced survival compared with cells cultured under NG conditions at all time points (P <0.05). D values of all tested strains were lower after LSMMG culture than after NG culture. Fourteen of 37 fatty acids examined were present in the bacterial membrane: nine saturated fatty acids (SFA) and five unsaturated fatty acids (USFA). The USFA/SFA ratio, a measure of membrane fluidity, was higher under LSMMG conditions than under NG conditions. Compared with control cells grown under NG conditions, cells cultured under LSMMG conditions showed downregulation of eight heat stress-related genes (average,-1.9-to-3.7-fold). The results of this study indicate that in a simulated space environment, heat resistance of E. coli O157:H7 decreased, and this might be due to the synergistic effects of the increases in membrane fluidity and downregulated relevant heat stress genes.",
author = "Kim, {H. W.} and Min-Suk Rhee",
year = "2016",
month = "5",
day = "1",
doi = "10.1128/AEM.00050-16",
language = "English",
volume = "82",
pages = "2893--2901",
journal = "Applied and Environmental Microbiology",
issn = "0099-2240",
publisher = "American Society for Microbiology",
number = "10",

}

TY - JOUR

T1 - Influence of low-shear modeled microgravity on heat resistance, membrane fatty acid composition, and heat stress-related gene expression in Escherichia coli O157

T2 - H7 ATCC 35150, ATCC 43889, ATCC 43890, and ATCC 43895

AU - Kim, H. W.

AU - Rhee, Min-Suk

PY - 2016/5/1

Y1 - 2016/5/1

N2 - We previously showed that modeled microgravity conditions alter the physiological characteristics of Escherichia coli O157:H7. To examine how microgravity conditions affect bacterial heat stress responses, D values, membrane fatty acid composition, and heat stress-related gene expression (clpB, dnaK, grpE, groES, htpG, htpX, ibpB, and rpoH), E. coli O157:H7 ATCC 35150, ATCC 43889, ATCC 43890, and ATCC 43895 were cultured under two different conditions: low-shear modeled microgravity (LSMMG, an analog of spaceflight conditions) and normal gravity (NG, Earth-like conditions). When 24-h cultures were heated to 55°C, cells cultured under LSMMG conditions showed reduced survival compared with cells cultured under NG conditions at all time points (P <0.05). D values of all tested strains were lower after LSMMG culture than after NG culture. Fourteen of 37 fatty acids examined were present in the bacterial membrane: nine saturated fatty acids (SFA) and five unsaturated fatty acids (USFA). The USFA/SFA ratio, a measure of membrane fluidity, was higher under LSMMG conditions than under NG conditions. Compared with control cells grown under NG conditions, cells cultured under LSMMG conditions showed downregulation of eight heat stress-related genes (average,-1.9-to-3.7-fold). The results of this study indicate that in a simulated space environment, heat resistance of E. coli O157:H7 decreased, and this might be due to the synergistic effects of the increases in membrane fluidity and downregulated relevant heat stress genes.

AB - We previously showed that modeled microgravity conditions alter the physiological characteristics of Escherichia coli O157:H7. To examine how microgravity conditions affect bacterial heat stress responses, D values, membrane fatty acid composition, and heat stress-related gene expression (clpB, dnaK, grpE, groES, htpG, htpX, ibpB, and rpoH), E. coli O157:H7 ATCC 35150, ATCC 43889, ATCC 43890, and ATCC 43895 were cultured under two different conditions: low-shear modeled microgravity (LSMMG, an analog of spaceflight conditions) and normal gravity (NG, Earth-like conditions). When 24-h cultures were heated to 55°C, cells cultured under LSMMG conditions showed reduced survival compared with cells cultured under NG conditions at all time points (P <0.05). D values of all tested strains were lower after LSMMG culture than after NG culture. Fourteen of 37 fatty acids examined were present in the bacterial membrane: nine saturated fatty acids (SFA) and five unsaturated fatty acids (USFA). The USFA/SFA ratio, a measure of membrane fluidity, was higher under LSMMG conditions than under NG conditions. Compared with control cells grown under NG conditions, cells cultured under LSMMG conditions showed downregulation of eight heat stress-related genes (average,-1.9-to-3.7-fold). The results of this study indicate that in a simulated space environment, heat resistance of E. coli O157:H7 decreased, and this might be due to the synergistic effects of the increases in membrane fluidity and downregulated relevant heat stress genes.

UR - http://www.scopus.com/inward/record.url?scp=84966460145&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84966460145&partnerID=8YFLogxK

U2 - 10.1128/AEM.00050-16

DO - 10.1128/AEM.00050-16

M3 - Article

C2 - 26944847

AN - SCOPUS:84966460145

VL - 82

SP - 2893

EP - 2901

JO - Applied and Environmental Microbiology

JF - Applied and Environmental Microbiology

SN - 0099-2240

IS - 10

ER -