Acetic acid bacteria (AAB) involved in cocoa fermentation from Ivory Coast: species diversity and performance in acetic acid production

The microbiota diversity identified during the cocoa fermentation and the benefits of the starter cultures use: an overview

“…Acetic bacteria, especially species of the Acetobacter genus, develop during this phase. Acetic acid is considered one of the main metabolites produced by an exothermic reaction (oxidizing ethanol to acetic acid), promoting embryo inactivation, increasing the permeability of the cell wall of the grain and the release of precursor molecules of aroma and chocolate flavour (Camu et al ., 2007; Nielsen et al ., 2007; Batista et al ., 2015; Soumahoro et al ., 2020).…”

“… 1: (Agyirifo et al ., 2019), 2: (Almeida et al ., 2018), 3: (Arana‐Sánchez et al ., 2015), 4: (Bastos et al ., 2018), 5: (Batista et al ., 2015), 6: (Bortolini et al ., 2016), 7: (Fernández Maura et al ., 2016), 8: (Gibe & Pangan, 2015), 9: (Hamdouche et al ., 2015), 10: (Ho et al ., 2015), 11: (Koné et al ., 2016), 12: (Lee et al ., 2019), 13: (Miguel et al ., 2017), 14: (Mota‐Gutierrez et al ., 2018), 15: (Ouattara et al ., 2017) 16: (Pereira et al ., 2017), 17: (Romanens et al ., 2018), 18: (Samagaci et al ., 2016), 19: (Schwenninger et al ., 2016), 20: (Serra et al ., 2019), 21: (Soumahoro et al ., 2020), 22: (Visintin et al ., 2017). …”

“…The diversity of these species is practically restricted to two genera: Acetobacter and Gluconobacter (Table 1). The species Acetobacter pasteurianus being the most identified in fermentation processes in Cameroon (Bortolini et al ., 2016; Mota‐Gutierrez et al ., 2018), Ivory Coast (Hamdouche et al ., 2015; Soumahoro et al ., 2020), Brazil (Miguel et al ., 2017; Serra et al ., 2019) and Honduras (Romanens et al ., 2018).…”

“…The lactic acid produced in the previous phase by LAB can be used as the only carbon source by A. pasteurianus, thus reinforcing a good interaction and synergy with the other microbial groups present in the fermentation. Thanks to the acetic acid produced from the oxidation of ethanol (produced by yeasts) and the consequent increase in the mass temperature, the cocoa seed loses its germinative power due to the death of the embryo, which initiates several structural and chemical reactions inside (Soumahoro et al, 2020). The oxidation reactions of lactic acid to acetoin occur via the a-acetolactate pathway and in a low proportion in acetic acid, since bacteria of the genus Acetobacter have low production and activity of the enzyme decarboxylase pyruvate (Pelicaen et al, 2019;De Vuyst & Leroy, 2020).…”

Sucesión microbiana durante la fermentación espontánea de cacao en unidades productivas

“…En una primera fase de la fermentación las levaduras y BAL predominan por las condiciones iniciales del medio (alta concentración de azúcares, medio ácido y anaerobiosis), lo que ocasiona la despectinización de la pulpa, y esto permite la entrada de oxígeno a la masa de fermentación [8]. Los productos de la fermentación heterofermentativa del ácido cítrico por parte de las BAL, genera un ligero incremento en el pH, lo que promueve el crecimiento de las BAA [9]. Estos procesos bioquímicos que se generan en la fermentación generan cambios que se ven reflejados en parámetros fisicoquímicos que influencian en la calidad del grano (pH, acidez, grado de fermentación, índice de grano, índice de mazorca, entre otros) [10].…”