Proteins Induced during Adaptation of Acetobacter aceti to High Acetate Concentrations

Abstract

As a typical product of microbial metabolism, the weak acid acetate is well known for its cytotoxic effects. In contrast to most other microbes, the so-called acetic acid bacteria can acquire significant resistance to high acetate concentrations when properly adapted to such hostile conditions. To characterize the molecular events that are associated with this adaptation, we analyzed global protein expression levels during adaptation of Acetobacter aceti by two-dimensional gel electrophoresis. Adaptation was achieved by using serial batch and continuous cultivations with increasing acetate supplementation. Computer-aided analysis revealed a complex proteome response with at least 50 proteins that are specifically induced by adaptation to acetate but not by other stress conditions, such as heat or oxidative or osmotic stress. Of these proteins, 19 were significantly induced in serial batch and continuous cultures and were thus noted as acetate adaptation proteins (Aaps). Here we present first microsequence information on such Aaps from A. aceti. Membrane-associated processes appear to be of major importance for adaptation, because some of the Aap bear N-terminal sequence homology to membrane proteins and 11 of about 40 resolved proteins from membrane protein-enriched fractions are significantly induced.

Study on fermentation conditions of palm juice vinegar by response surface methodology and development of a kinetic model

“…It has been reported that the optimum pH for the growth of acetic acid bacteria is 5.5-6.3 (Holt et al, 1994). A. aceti can adapt to high acetic acid conditions by producing 35 proteins specifically induced during acetate adaptation (Steiner et al, 2001). The literature reports that cell numbers of A. aceti decreased faster at pH 3.4 under strictly anaerobic conditions (Joyeux, et al, 1984).…”

A Specialized Citric Acid Cycle Requiring Succinyl-Coenzyme A (CoA):Acetate CoA-Transferase (AarC) Confers Acetic Acid Resistance on the Acidophile Acetobacter aceti

“…The molecular mechanisms of acetic acid resistance in Acetobacter aceti include adaptation of the cytoplasmic components (9,14) to internal acidification (32), acetic acid efflux via the AatA acetic acid:proton antiporter (31,39), and production of acid-inducible proteins identified by proteomic screens, many with undefined biochemical roles (28,52).…”

Putative ABC Transporter Responsible for Acetic Acid Resistance in Acetobacter aceti

“…A genetic approach identified a gene cluster responsible for acetic acid resistance in Acetobacter aceti, which includes aarA encoding a citrate synthase, aarB encoding a functionally unknown protein, and aarC encoding a protein probably involved in acetic acid assimilation (16,17). A biochemical approach to determine changes in protein profiles in response to acetic acid showed that the production of many proteins was changed (27,38). One of the proteins whose production was enhanced in response to acetic acid was identified as aconitase (27).…”