Isolation of thermotolerant and high acetic acid-producing Acetobacter pasteurianus from Ivorian palm wine

Abstract

The aim of this work was to identify acetic acid bacteria expressing technological characteristics for further use in vinegar production in tropical countries. It was focused on isolation and identification of thermotolerant acetic acid bacteria strains from Elaeis guineensis wine of Côte d'Ivoire (Ivorian palm wine). A screening was performed to find out strains with high vinegar production, tolerant against high ethanol, acid and sugar concentrations as well as tolerating high production temperatures. Among 104 isolated strains, 5 were selected for their growth ability, acetification capacity (acetic acid production higher than 30 g/l) and suroxydation at 37°C. Tolerance against 6% acetic acid and 9% ethanol was observed. Osmotolerance study showed tolerance against 5% and 10% glucose giving 100% and 50% relative growth, respectively. Resistance against desiccation showed survival rate of 50% at 37°C after 5 h treatment and 10% after 20 h treatment. The best aeration rate in flasks for acetification was 70%. Polyphasic identification study based on biochemical, physiological and molecular characterization showed that the 5 isolates were all Acetobacter pasteurianus. Owing to their potentialities, these strains may be used as starters in vinegar production after conducting preservation studies.

Occurrence of High Acetic Acid-Producing Bacteria in Ivorian Cocoa Fermentation and Analysis of Their Response to Fermentative Stress

“…For instance, Lu et al [30]reported an acidproducing Acetobactersp strains from spoiled banana in Taiwan, with short lag phase (12 h). Furthermore, no lag phase for acid production was observed in Acetobacterpasteurianus strains isolated from palm wine [29] and traditional rice fermentation [22].The long lag phase observed in our AAB strains studied, may be indicative of their behavior in their natural ecosystem (cocoa fermentation) and seems to be a common property for AAB involved in cocoa fermentation since Romero-Cortes et al [27]also reported a long lag phase (2 days) in AAB strain Acetobactertropicalis from Mexican cocoa fermentation. In fact, maximum production of acetic acid during cocoa fermentation occurs generally after the third day [7,25]and AAB strains should keep a low level of acid production until this period which corresponds to the occurrence of reactions leading to formation of cocoa and chocolate aroma precursors.…”

“…This production is particularly higher than that from AAB in Mexican cocoa fermentation reported by Romero-Cortes et al [27]which was 25 g/L. However, Sharafi et al [28] isolated AAB(Acetobacterpasteurianus) from fruit with capacity to produce up to 100 g/L of acetic acid while Konaté et al [29]reported AAB(Acetobacterpasteurianus) as the best acid producer from traditional palm wine producing 30 g/L of acetic acid. At date, the strain 121D isolated in this study, present the higher acetic acid production from cocoa fermentation.…”

Screening of Acetic Acid Bacteria from Pineapple Waste for Bacterial Cellulose Production using Sago Liquid Waste

“…The characteristics of LKN6 isolate which are ethanol and sugar tolerant indicated that isolate LKN6 is able to produce acetic acid. Konate et al (2014) stated that the AAB that are tolerant to high ethanol and sugar concentrations have the ability to produce acetic acid.…”

Screening and Characterization of New Acetobacter fabarum and Acetobacter pasteurianus Strains with High Ethanol–Thermo Tolerance and the Optimization of Acetic Acid Production

“…According to [17], A. aceti subspecies aceti is capable of producing AA at 37 • C after a three-day lag phase of production. Other authors have isolated strains of A. pasteurianus from palm wine, Cacao and apple that are capable of producing AA at 39 • C [22], at 47 Tolerance in AAB to high temperatures can be achieved by thermal adaptation of the isolated strains. This thermal adaptation plays an important role not only in the reduction of the cooling system, but also in the protection of the fermentation process against accidental failures of the thermal management [24].…”