Feasible acetic acid fermentations of alcoholic and sugary substrates in combined operation mode

Abstract

Starting from small-scale batch cultivations, acetic acid fermentations in static and submerged systems have been performed by a single acetic acid bacterial strain. To provide user-friendly selected starter cultures for industry, the versatility of these cultures in using different oxidation substrates under different conditions was assessed. In all cases, vinegars with the desired acetic acid, residual ethanol and reducing sugar contents were obtained. An appropriate small-scale batch cultivation subjected to strict process control was pivotal for obtaining the desired acetic acid concentrations and an active culture for submerged fermentation. This achievement enabled the generation of selected starter cultures for submerged vinegar production, which reached an acetic acid content of 8.00–9.00% (w/v), as well as prototype-scale vinegar production. The production of vinegars with reducing sugars in the range of 15.00–27.00 (% w/v) was achieved, and cellulose production was avoided. The dominance of the microbial culture in this process was shown via (GTG)5-PCR. These results are valuable for introducing the use of selected acetic acid bacteria cultures in industrial vinegar production

Cost-effective production of bacterial cellulose using acidic food industry by-products

“…Culturing the bacterium G. sucrofermentans B-11267 on TS and whey, a pH increase was observed, which is most likely due to the consumption of organic acids of stillage and whey. The concentration of monocarboxylic acids in TS medium after 3 days of cultivation was negligible, suggesting that they were metabolized via TCA cycle or that the formed oxaloacetate was decarboxylated into pyruvate that is used by the gluconeogenesis pathway to produce glucose, as previously stated for K. xylinus 39 …”

“…In addition, acetic acid can be used in the pathway of gluconeogenesis, increasing glucose availability. 39 …”

“…The concentration of monocarboxylic acids in TS medium after 3 days of cultivation was negligible, suggesting that they were metabolized via TCA cycle or that the formed oxaloacetate was decarboxylated into pyruvate that is used by the gluconeogenesis pathway to produce glucose, as previously stated for K. xylinus . 39 …”

“…It can be transformed into acetyl-CoA and metabolized in tricarboxylic acid (TCA) cycle to generate ATP. In addition, acetic acid can be used in the pathway of gluconeogenesis, increasing glucose availability 39 …”

Bio-produced Acetic Acid: A Review

“…Traditional vinegar production generally use indigeniuos starter culture instead of applying selected (monophyletic) starter culture (SSC), because of the low price of the product. However a recent study shows, that a systematic process development with SSC can confirm the feasibility of applying selected strain [30].…”