The effect of pH on growth of Clostridium botulinum type A and expression of bontA and botR during different growth stages

Foodborne Pathogens and Disease
Tao LiHui Wang

Abstract

In this study, the effects of pH on the growth, relative expressions of bontA and botR genes, and neurotoxin formation of foodborne pathogens Clostridium botulinum type A were systematically studied throughout its growth stage. As in the previous reports, no C. botulinum growth was observed at extremely acidic pH. However, the effect of alkaline pH on the growth and neurotoxin production of C. botulinum was first revealed in this study. The maximum growth rate at pH 9.0 was similar to that at other pH values, although the lag phase at pH 9.0 was 16 h longer than that at pH 8.0. The peak of bontA mRNA expression at pH 9.0 was only 15.5% compared with that at pH 7.0. However, the neurotoxin concentration quantified in the cultures did not differ significantly. BotR is a known regulatory protein of bontA. The quantitative relationship between bontA and botR at different growth stages was first determined in this study. The mRNA levels of bontA were found to be positively correlated with those of botR, and the ratio of the mRNA transcript varied with pH. All these findings provide important physiological information on C. botulinum and thereby contribute to the improvement of food safety.

References

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Citations

Feb 28, 2014·Bioprocess and Biosystems Engineering·Igor Viana BrandiEliane Macedo Sobrinho
Jan 17, 2015·Research in Microbiology·Chloé Connan, Michel R Popoff
Jun 25, 2017·Systematic and Applied Microbiology·German A Estrada-BonillaElke J B N Cardoso

Methods Mentioned

BETA
enzyme-linked immunosorbent assays
PCR
electrophoresis
ELISA

Related Concepts

BotR protein, Clostridium botulinum
Bacterial Proteins
Food Contamination
Food Microbiology
Hydrogen-Ion Concentration
Alpha-Neurotoxins
RNA, Bacterial
Poly(A) Tail
Trans-Activators
Gene Expression Regulation, Bacterial

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