ATP requirements for benzoic acid tolerance in Zygosaccharomyces bailii

Abstract

Aims: To calculate the energetic requirements for benzoic acid tolerance in Zygosaccharomyces bailii in chemostat experiments. Methods and Results: A 5.6-l stirred-tank chemostat was used. The yield of ATP (Y ATP ) was calculated under nitrogen atmosphere, assuming equimolar ATP and ethanol production. Under these conditions Y ATP , equal to 20 g mol )1 of ATP, was not affected by the acid, whereas the maintenance coefficient (m ATP ) increased from)1 in the absence of the acid to 4.8 in the presence of 0.67 mmol l )1 undissociated benzoic acid. These ATP requirements were similar to those found in Saccharomyces cerevisiae with other weak acids. Conclusions: No significant differences have been found in the energy expended to cope with the acid between sensitive and tolerant species. Therefore, the main difference between tolerant and sensitive species could rely on cellular features that would not need extra energy in terms of ATP. Significance and Impact of the Study: The potential mechanisms involved in the tolerance to weak acids in yeasts have been extensively studied but their actual relevance has not been assessed. Our results suggest that future efforts should concentrate on nonexpending energy features as membrane permeability and metabolic tolerance in the cytoplasm.

Controlling microbial contamination during hydrolysis of AFEX-pretreated corn stover and switchgrass: effects on hydrolysate composition, microbial response and fermentation

“…When yeast are grown under glucose-depleted conditions, significant amounts of benzoic acid can accumulate [ 44 ]. The required redirection of ATP toward active export could reduce cell growth [ 55 – 57 ]. The comparatively high concentrations of benzoic acid in all hydrolysates may also be one reason for the high sensitivity of the PDR12 knockout mutant, which has lost a weak acid (i.e., benzoate) inducible transporter and may experience high levels of benzoate accumulation [ 57 ].…”

The effect of preservatives on Alicyclobacillus acidoterrestris and Propionibacterium cyclohexanicum in fruit juice

“…Its antimicrobial activity is due to the undissociated acid the concentration of which declines as the pH level increases (Batchelor, 1984). Although effective against yeasts and bacteria this preservative can be degraded by some bacteria, for example, Burkholderia cepacia (Philippe, Vega, & Bastide, 2001) and some yeasts such as Zygosaccharomyces baillii (Leyva & Peinado, 2005) which may become resistant to benzoic acid (Batchelor, 1984).…”

An effect of positional isomerism of benzoic acid derivatives on antibacterial activity against Escherichia coli

“…The mechanism action implies the diffusion through the membrane of the undissociated acid at low external pH. Later in the cytoplasm where pH is near neutrality, the weak acid would dissociate releasing one anion and one proton, with the subsequent acidification of the cytoplasm and accumulation of the anion [ 24 ]. The connection of both hydroxyl and methoxyl substituents to the benzoic acid significantly shortened the time of bacterial cells killing.…”