Question

During cocoa pulp fermentation, how does the cross-feeding dynamic between lactic acid bacteria, yeast, and acetic acid bacteria influence energy generation AND cell biogenesis in acetic acid bacteria and successful fermentation of cocoa pulp.

Answer 1

This is mainly done by the organism acetic acid bacteria (AAB) .They play an important role during cocoa fermentation and their main product, acetate, is a major driver for the development of the desired cocoa flavors. The metabolism of these bacteria under cocoa pulp fermentation-simulating conditions can be done A carefully designed combination of parallel 13C isotope labeling experiments allows elucidation of intracellular fluxes in the complex environment of cocoa pulp, when lactate and ethanol were included as primary substrates among undefined ingredients.This demonstrate that AAB exhibit a functionally separated metabolism during coconsumption of two-carbon and three-carbon substrates. Acetate is almost exclusively derived from ethanol, while lactate serves for the formation of acetoin and biomass building blocks. Although this is suboptimal for cellular energetics, this allows maximized growth and conversion rates. The functional separation results from a lack of phosphoenolpyruvate carboxykinase and malic enzymes, typically present in bacteria to interconnect metabolism. In fact, gluconeogenesis is driven by pyruvate phosphate dikinase. Consequently, a balanced ratio of lactate and ethanol is important for the optimum performance of AAB. As lactate and ethanol are individually supplied by lactic acid bacteria and yeasts during the initial phase of cocoa fermentation, respectively, this underlines the importance of a well-balanced microbial consortium for a successful fermentation process. Indeed, AAB performed the best and produced the largest amounts of acetate in mixed culture experiments when lactic acid bacteria and yeasts were both present.So we can say that by the cross-feeding dynamic between lactic acid bacteria, yeast, and acetic acid bacteria influences the energy generation.