scholarly journals Glutamate and histidine improve both solvent yields and the acid tolerance response of Clostridium beijerinckii NCP 260

2016 ◽  
Vol 120 (5) ◽  
pp. 1271-1281 ◽  
Author(s):  
B.W.P. Reeve ◽  
S.J. Reid
Keyword(s):  
Acid Tolerance ◽  
Clostridium Beijerinckii ◽  
Acid Tolerance Response ◽  
Tolerance Response

Effect offurmutation on acid-tolerance response and in vivo virulence of avian septicemicEscherichia coli

2002 ◽  
Vol 48 (5) ◽  
pp. 458-462 ◽  
Author(s):  
Chengru Zhu ◽  
Musangu Ngeleka ◽  
Andrew A Potter ◽  
Brenda J Allan
Keyword(s):  
Parent Strain ◽  
Acid Tolerance ◽  
Wild Type ◽  
Acid Tolerance Response ◽  
E Coli ◽  
Regulator Protein ◽  
In The Wild ◽  
Tolerance Response ◽  
Wild Type Parent

The Fur (ferric uptake regulator) protein is a master regulator of iron metabolism in gram-negative bacteria. In the present study, the effect of a partial deletion of the fur gene on the acid-tolerance response and in vivo virulence of avian Escherichia coli was examined. The fur mutant was unable to trigger the acid-tolerance response as observed in the wild-type parent strain. However, the mutant was as virulent as the wild-type parent strain when tested in 1-day-old chickens by subcutaneous inoculation. These data indicate that the fur gene is involved in the acid-tolerance response but not involved in the virulence of E. coli, as detected by the ability to cause septicemia in our experimental infection.Key words: E. coli, fur, acid-tolerance response.

scholarly journals Adaptive acid tolerance response (ATR) in Aeromonas hydrophila

Microbiology ◽  
1994 ◽  
Vol 140 (7) ◽  
pp. 1731-1736 ◽  
Author(s):  
K. L. KAREM ◽  
J. W. FOSTER ◽  
A. K. BEJ
Keyword(s):  
Aeromonas Hydrophila ◽  
Acid Tolerance ◽  
Acid Tolerance Response ◽  
Tolerance Response

High-Salt Preadaptation of Vibrio parahaemolyticus Enhances Survival in Response to Lethal Environmental Stresses

2014 ◽  
Vol 77 (2) ◽  
pp. 246-253 ◽  
Author(s):  
SAI SIDDARTH KALBURGE ◽  
W. BRIAN WHITAKER ◽  
E. FIDELMA BOYD
Keyword(s):  
Stress Response ◽  
Marine Environment ◽  
Vibrio Parahaemolyticus ◽  
High Salinity ◽  
Acid Stress ◽  
Acid Tolerance ◽  
High Salt ◽  
Wild Type ◽  
Acid Tolerance Response ◽  
Tolerance Response

Adaptation to changing environmental conditions is an important strategy for survival of foodborne bacterial pathogens. Vibrio parahaemolyticus is a gram-negative seafoodborne enteric pathogen found in the marine environment both free living and associated with oysters. This pathogen is a moderate halophile, with optimal growth at 3% NaCl. Among the several stresses imposed upon enteric bacteria, acid stress is perhaps one of the most important. V. parahaemolyticus has a lysine decarboxylase system responsible for decarboxylation of lysine to the basic product cadaverine, an important acid stress response system in bacteria. Preadaptation to mild acid conditions, i.e., the acid tolerance response, enhances survival under lethal acid conditions. Because of the variety of conditions encountered by V. parahaemolyticus in the marine environment and in oyster postharvest facilities, we examined the nature of the V. parahaemolyticus acid tolerance response under high-salinity conditions. Short preadaptation to a 6% salt concentration increased survival of the wild-type strain but not that of a cadA mutant under lethal acid conditions. However, prolonged exposure to high salinity (16 h) increased survival of both the wild-type and the cadA mutant strains. This phenotype was not dependent on the stress response sigma factor RpoS. Although this preadaptation response is much more pronounced in V. parahaemolyticus, this characteristic is not limited to this species. Both Vibrio cholerae and Vibrio vulnificus also survive better under lethal acid stress conditions when preadapted to high-salinity conditions. High salt both protected the organism against acid stress and increased survival under −20°C cold stress conditions. High-salt adaptation of V. parahaemolyticus strains significantly increases survival under environmental stresses that would otherwise be lethal to these bacteria.

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