Acetobacter Aceti Research Articles

Vinegar production from Citrus bergamia by-products and preservation of bioactive compounds

Processing citrus fruits results in significant amount of wastes; however, citrus by-products still contain high amounts of polyphenolic and other bioactive value-added compounds. In addition, bergamot (Citrus bergamia) wastes contain two compounds—brutieridin and melitidin—which exhibit statin-like properties. Recently, novel fermented products containing bioactive compounds received increasing attention because of their health-promoting functions. In this study, the bioconversion of citrus wastes in vinegars with high content in bioactive and aromatic compounds was performed, detecting a high permanence at the end of the process of the main compounds of interest, especially brutieridin and melitidin. In addition, the sensory analysis of the vinegars was performed, obtaining good performances. According to the adopted preselection procedure, 50 out of the 54 strains of acetic acid bacteria were excluded because of their low aptitude to grow in the tested conditions. The best vinegar was produced from citrus wine at pH 2.90 using the Acetobacter aceti strain DSM_3508T as microbial starter. This research has demonstrated—for the first time—the possibility to produce citrus vinegar at high content of brutieridin and melitidin and other bioactive compounds using selected microbial starters.

Study the Effect of pH on the Fermentation Anaerobic-Aerobic Siwalan (Borassus flabellifer L.) Sap to Produce Acetic Acid

This research is to study the effect of ethanol fermentation aerobic pH on acetic acid product. Anaerobic fermentation uses saccharomyces cerevisiae to produce ethanol, and aerobic fermentation uses acetobacter acetic for acetic acid production. In aerobic ethanol fermentation using pH 3; 3.5; 4 and 5. The ethanol concentration was evaluated using GC ULTRA Scientific Gas Chromatography, DSQ II detector, and MS 220 column. Acetic acid produced was analyzed using an alkalymetric method. Anaerobic fermentation uses Saccharomyces cerevisiae with 1-day log phase, while aerobic fermentation uses acetobacter aceti with a 5-day log phase. Fermentation using saccharomyces cerevisiae within 24 hours so that reduction sugar could stably decrease, optimum ethanol could be got at optimum pH 6 which could decrease 55 % of reducing sugar concentration to produce 8,20583 %v/v ethanol. Fermentation acetate acid content observed in 3 days at pH 6 and 30 ⁰C will produce 6,659 g/l also shows that pH 4-6 at 30 ⁰C will produce 6,605 g/l acetate acid. Aerobic fermentation of acetate acid in 3 days shows that pH 4-6 is highly affected by temperature at 30⁰C. Statistical analysis shows, in ethanol production pH and fermentation time give significant effect, but interaction has no significant effect.

Increasing the acetification rate of Acetobacter aceti adsorbed on luffa sponge using recycle of incremental oxygenated medium.

Speeding up the production of vinegar from rice wine by acetification, using a packed-bed bioreactor with a luffa sponge matrix (LSM) as adsorption carrier of acetic acid bacteria (AAB), and the effect of oxygenation of the recycled medium were investigated. The 0.06 L/min recycle of medium resulted in a high oxygen-transfer coefficient, while optimal dissolved oxygen (DO) of the medium maximized planktonic AAB cell growth with no contamination due to high acid in an external reservoir without LSM. The highest acetification rate (ETA) of 2.857 ± 0.1g/L/day was achieved with DO 3.5-4.5ppm at 35 ± 1°C. To increase ETA, the optimized oxygenated medium was externally supplied and recycled at the ratio of 0.1. Therefore, acetification was conducted in both the bioreactor and reservoir resulting in an increased ETA (6 ± 0.2g/L/day). This also aligned with the highest system AAB biomass (confirmed by scanning electron microscopy). Under the recycled oxygenated medium supply consistently high biotransformation yields (average 77.3%) were observed over nine sequential cycles. Meanwhile, an average ETA of 6.3 ± 0.2g/L/day was obtained. This method can have practical applications in improving the efficiency and speeding up small-scale vinegar production.

Influence of sucrose and Acetobacter aceti adition to acetic acid content on coconut water vinegar

Vinegar can be made from coconut water through a fermentation process in two stages, namely alcohol fermentation used yeast in an anaerobic state and acetic acid fermentation using Acetobacter aceti in aerobic. The present work was to investigate the influences of sucrose addition on alcohol fermentation and Acetobacter aceti on acetic acid fermentation to the acetic acid and phenol content of product vinegar. Method of the experiment was used in a completely randomized design by factorial with two replications. The first factor was sugar concentration (A) consisting of 2 levels i.e 15% and 20%, whereas the second factor was the concentration of inoculum of A.aceti consisting of 3 levels i.e 10%, 15% and 20%. Observations determined for ethanol content, pH, specific gravity, acetic acid andand phenol content. The results showed that ethanol and acetic acid contents tended to increase, and the pH value decreased, while the specific gravity almost constant. Then, for acetic acid fermentation was showed increasing the acetic acid content for all treatment in days 49, especially for the addition of 15% sucrose and 10% A.aceti.

Bacteriophages as an Up-and-Coming Alternative to the Use of Sulfur Dioxide in Winemaking.

Certain acetic and lactic acid bacteria are major causes of quality defects in musts and wines, giving rise to defects such as a “vinegary,” “sharp, like nail polish-remover” taste or preventing alcoholic and/or malolactic fermentation. Sulfur dioxide is the major tool currently used in the control of these bacteria in wine. The aim of this work was to isolate bacteriophages from musts and wine of different grape varieties that were able to eliminate lactic and acetic acid bacteria spoilages at the laboratory scale. Musts obtained from grape-berries of Vitis vinifera cv. Chardonnay and Moscatel and a red wine made with V. vinifera cv. Tintilla de Rota were used to isolate bacteriophages. Bacteriophages were obtained from each of the musts and the wine and belonged to the order Caudovirals and the family Tectivirals. They were isolated by classical virology methods and identified by electron microscopy. The host bacteria used in the study were lactic acid bacteria of the species Lactobacillus hilgardii, Lactobacillus plantarum, and Oenococcus oeni and the acetic bacteria Acetobacter aceti. A comparative study was performed by adding phage titrations and SO2 to musts and wines, which had been previously inoculated with bacteria, to study the effectiveness of bacteriophages against bacteria. The comparative study showed that some bacteriophages were as effective as sulfur dioxide at low concentrations.

Analysis of the basic components and free amino acid composition of pineapple fruit vinegar

Acetic acid fermentation is an essential step in producing high-quality vinegar. In this study, the alcoholic medium was used as a seed broth for acetic fermentation using Acetobacter aceti as the inoculum for approximately 7 days at 32℃ to obtain 45.87g/L acetic acid. During the Acetic acid fermentation stage, the content of the total polyphenols decreased first and then increased. Based on amino acid analyzer analysis, pineapple vinegar contains 18 kinds of free amino acids. And the contents of sweet and umami free amino acids are the main free amino acids, followed by bitter amino acids.

Activity and Stability of the Alcohol Biosensor Using Acetobacter aceti Biofilm on Screen-Printed Carbon Electrode

Most of the alcohol analytical methods are robust and instrumentally expensive. An alternative of ethanol biosensor based on selected biofilm forming Acetobacter aceti bacteria producing alcohol oxidase was constructed on a screen-printed carbon electrode. The enzyme specifically oxidizes the ethanol and generate electrical current that then electrochemically detected and measured by cyclic voltammetry method. A scanning electron microscopic analysis indicated that the biofilm was formed firmly in the electrode. This constructed biosensor reached its optimum at biofilm formed by bacteria of 1.33 × 1010 cells/ml, temperature of 27°C, and pH 7. The enzyme kinetic had KM and Vmax AOX values of 3.5 mm and 125 μA respectively. The biosensor had detection and quantization limit of 0.003 and 0.009%, respectively, and a sensitivity of 57.29 μA (%)-1. A linearity and relative deviation value were revealed at 0.993 and 1.95% respectively. The biosensor was relatively specific and had no interferences with methanol, sodium chloride and citric acid as the common interferences of ethanol compounds. Furthermore, the biosensor had been stably for at least 55 days. Therefore, this constructed biosensor should be developed into a prototype for a practical effective analysis.

Starter consortia for on-farm cocoa fermentation and their quality attributes

A starter consortium of Saccharomyces cerevisiae (Y), Lactobacillus plantarum (LAB), and Acetobacter aceti (AAB) was defined to ferment the Cocoa beans (Theobroma cacao). Emphasis was laid to optimize the microbial concentration with a functional ratio of selected cultures. A central composite rotatable design (CCRD) was employed to study the effect of inoculum size (0–20% w/v) with alcohol, titrable acidity, polyphenols, anthocyanin, cut test, and sensory as response variables. The significant (p < 0.05) response surface models with high coefficients of determination values (R2) ranging from 0.82 to 0.93 were considered for the experimental data, which represented the polynomial response models for describing the constraints. Based on the design, the concentration of consortia ranged 9.03X103 CFU/g of Y, 5.9X104 CFU/g of LAB, and 7.0X104 CFU/g of AAB. The graphical optimization of superimposed contour plots fulfilled the desired metabolites; alcohol (Y1) ≤ 11 mg/g, titrable acidity (Y2) ≥ 0.25%, polyphenols (Y3) ≤ 4.0 mg/g, anthocyanin (Y4) ≤ 14 mg/g, sensory (Y5) ≥ 6.0, and cut test (Y6)≥95%. Thus, validation through a field trial was confirmed to adopt the techno-economic feasibility on-farm process with precise inoculums. The effect of starter consortia on Cocoa fermentation and quality was found to be significant.

Characteristics of Black Glutinous Rice Vinegar as Traditionally Fermented Product of Yeast Tapai and Acetobacter aceti

As the source of nutrition in food, the product of rice vinegar also has advantages as anti-diabetes, anti-oxidation, anti-cholesterol and anti-bacterial which contribute to health. For the current research, the fermentation of black glutinous rice for producing rice vinegar used microbes contained in yeast tape and acetic acid bacteria (BAA). To get high-quality vinegar products, two stages of the optimization process are carried out. The first process is the fermentation process for the production of alcohol using yeast from tapai and the second process is a fermentation process for the production of acetic acid using Acetobacter aceti. The products are analyzed for their physicochemical and functional properties. Vinegar produced in the processes contained 52.04 g/L acetic acid, 21.83% anthocyanin level, 1844.72 (GAE mg / L) total phenolic and 92.71% DPPH inhibition.

Sensitive and stable ethanol biosensor development based on Acetobacter aceti biofilm for halal detection of food and beverages

Sensitive and stable ethanol biosensor development based on Acetobacter aceti biofilm for halal detection of food and beverages

Acetobacter sacchari sp. nov., for a plant growth-promoting acetic acid bacterium isolated in Vietnam

Two bacterial strains, designated as isolates VTH-Ai14T and VTH-Ai15, that have plant growth-promoting ability were isolated during the study on acetic acid bacteria diversity in Vietnam. The phylogenetic analysis based on 16S rRNA gene sequences showed that the two isolates were located closely to Acetobacter nitrogenifigens RG1T but formed an independent cluster. The phylogenetic analysis based on 16S rRNA gene and three housekeeping genes’ (dnaK, groEL, and rpoB) sequences were analyzed. The genomic DNA of the two isolates, VTH-Ai14T and VTH-Ai15, Acetobacter nitrogenifigens RG1T, the closest phylogenetic species, and Acetobacter aceti NBRC 14818T were hybridized and calculated the %similarity. Then, phenotypic and chemotaxonomic characteristics were determined for species’ description using the conventional method. The 16S rRNA gene and concatenated of the three housekeeping genes phylogenetic analysis suggests that the two isolates were constituted in a species separated from Acetobacter nitrogenifigens, Acetobacter aceti, and Acetobacter sicerae. The two isolates VTH-Ai14T and VTH-Ai15 showed 99.65% and 98.65% similarity of 16S rRNA gene when compared with Acetobacter nitrogenifigens and Acetobacter aceti and they were so different from Acetobacter nitrogenifigens RG1T with 56.99 ± 3.6 and 68.15 ± 1.8% in DNA-DNA hybridization, when isolates VTH-Ai14T and VTH-Ai15 were respectively labeled. Moreover, the two isolates were phenotypically distinguished from Acetobacter nitrogenifigens in growth in the presence of 0.35% acetic acid (v/v), on nitrogen-free LGI medium and D-mannitol, and in no ability to solubilize phosphate. Therefore, the two isolates, VTH-Ai14T(= VTCC 910031T= BCC 67843T= TBRC 11175T= NRIC 0977T) and VTH-Ai15 (= VTCC 910032 = BCC 67844 = TBRC 11176 = NRIC 0978), can be assigned to an independent species within the genus Acetobacter, and the name of Acetobacter sacchari sp. nov. is proposed for the two isolates.

Study of pH Effect on the Anaerobic-Aerobic Fermentation of Siwalan &lt;i&gt;(Borassus flabellifer L.)&lt;/i&gt; Sap to Produce Acetic Acid

Siwalan (Borassus flabellifer L.) is a palm family that is widely planted in the Tuban area of ​​East Java. Siwalan sap has a relatively high sugar content of about 10-15 g / 100 ml. The sap is obtained by tapping the inflorescences. In general, siwalan sap is used for fresh drinks or alcoholic beverages with maximum storage in 3 days. Based on the sugar content in the sap of siwalan, acetic acid products can be made through fermentation of glucose to ethanol, then the ethanol is fermented into acetic acid. Acetic acid is widely used as a preservative of food and health drinks. The purpose of this research is to study the effect of ethanol fermentation aerobic pH on acetic acid product. Anaerobic fermentation uses saccharomyces cereviceae to produce ethanol, and aerobic fermentation uses acetobacter aceti for acetic acid production. In aerobic ethanol fermentation using pH 3; 3.5; 4 and 5. The concentration of ethanol was analyzed using GC ULTRA Scientific Gas Chromatography, DSQ II detector, and MS 220 column. Acetic acid produced from the aerobic fermentation process was analyzed using an alkalimetric method. Anaerobic fermentation uses Saccharomyces cereviceae with 1-day log phase, while aerobic fermentation uses acetobacter aceti with a 5 day log phase. Aerobic fermentation to produce acetic acid was observed in 5 days to obtained maximum acetic acid concentration, the highest acetic acid concetration is about 2.595 g/l and yield of acetic acid is obtained 0.519% (b/v) at pH 5. Low acetic acid concentration due to low intitial sugar content in siwalan sap.

Biofilm inhibition and corrosion resistance of 2205-Cu duplex stainless steel against acid producing bacterium Acetobacter aceti

Acid producing bacterium Acetobacter aceti causes pitting corrosion of stainless steel (SS). This work investigated the enhanced resistance of 2205-Cu duplex stainless steel (DSS) against biocorrosion by A. aceti in comparison with 2205 DSS using electrochemical and surface analysis techniques. With the addition of Cu to 2205 DSS, biofilms on the 2205-Cu DSS surface were inhibited effectively. The largest pit depth on 2205-Cu DSS surface in the presence of A. aceti was 2.6 μm, smaller than 5.5 μm for 2205 DSS surface. The icorr was 0.42 ± 0.03 μA cm−2 for 2205-Cu DSS in the biotic medium, which was much lower than that for 2205 DSS (3.69 ± 0.65 μA cm−2). All the results indicated that the A. aceti biofilm was considerably inhibited by the release of Cu2+ ions from the 2205-Cu DSS matrix, resulting in the mitigation of biocorrosion by A. aceti.

Development of a novel selective medium for the isolation and enumeration of acetic acid bacteria from various foods

Acetic acid bacteria (AAB) are gram-negative, obligate aerobic bacteria that produce acetic acid from alcohols or sugars. AAB are ubiquitous and found in many food products, including vinegar and wine. Owing to the lack of a suitable selective culture medium and the fastidious nature of AAB in food samples, ecological studies have been fundamentally limited for decades. Here, we developed a novel selective medium (AAB-selective agar; ABS) for AAB from food samples and evaluated its performance in comparison with glucose-yeast extract-calcium carbonate agar (GYC). In inclusivity tests, 16 species of AAB showed good growth on both ABS and GYC. Remarkably, the growth of 21 non-AAB strains was inhibited on ABS but not on GYC, suggesting the high exclusivity of the novel selective medium (p < 0.05). In artificial AAB-positive food samples, including wine, vinegar, yogurt, fruit, and kimchi, ABS provided better visual differentiation of AAB colonies, showing green colonies with a yellow halo surrounded by no competing colonies. Moreover, in ABS, a significantly greater number of AAB colonies were recovered from yogurts, fruits, and kimchi (Acetobacter aceti ATCC 15973 in yogurt, 4.24 ± 0.17 vs. 3.80 ± 0.14; Gluconobacter oxydans ATCC 15163 in fruit, 4.87 ± 0.07 vs. 4.53 ± 0.15; Gluconacetobacter hansenii ATCC 35959 in kimchi, 4.25 ± 0.14 vs. 3.85 ± 0.12; p < 0.05). Finally, a total of five novel AAB strains were isolated from 10 vinegar and 10 kimchi samples using ABS, while unsuccessful using GYC, demonstrating the superior performance of ABS in isolating new AAB strains or detecting AAB contamination.

Phenolic composition, antioxidant and antibacterial properties, and in vitro anti-HepG2 cell activities of wild apricot (Armeniaca Sibirica L. Lam) kernel skins

The polyphenols profiles of the methanol extracts of bitter apricot [Armeniaca Sibirica (L.)] kernel skins (AKS) were analysed by liquid chromatography-electrospray ionization mass spectrometry. The antioxidan, anticancer effect on HepG2 cell and antibacterial properties of the AKS polyphenol extracts were further characterized in vitro. Polyphenol compounds (35), including nine phenolic acids, thirteen anthocyanins and thirteen flavonoids, were identified in AKS for the first time. The content of apigenin 7-O-glucoside, (cyanidin 3-(4″-acetylrutinoside), 3- (6″-acetylglucoside)-5-glucoside and salicylic acid was relatively high than the others. The AKS polyphenols strongly reduced Fe3+ and exhibited good scavenging activity towards 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) free radicals, 1,1-diphenyl-1-picrylhydrazyl free radicals, hydroxyl radicals, superoxide anions and hydrogen peroxide. The AKS polyphenols could regulate oxidant stress in HepG2 cells by downregulating reduced glutathione, upregulating oxidative glutathione, malondialdehyde and advanced oxidation protein products, and reduced cell viability to induce apoptosis of HepG2 cells in vitro. The AKS polyphenols showed strong antibacterial activity against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Acetobacter aceti and Bacillus cereus. Therefore, the antioxidant, inhibitory effect on HepG2 cells and antimicrobial activity of the AKS polyphenols were distinct and worthy of further consideration for medical industry applications.

Acceleration of cocoa fermentation through the action of bacteria (Acetobacter aceti) and yeast (Saccharomyces cerevisiae)

Introductionthe management of the curriculum in teacher training within the Catholic University of Salta in the School of Education and Teacher Improvement, this thought from a deductive perspective in which theoretical processes are established that allow the explanation of the curriculum in terms of teacher training and its impact on the organizational articulation. Objectiveto specify a strategic articulated intervention device that requires the constitution of a new emancipatory discourse. Materials and methodsWe present a qualitative research that analyzes the problems and variables established in the study. ResultsThe process of rupture leads us to reflect on the teaching position in the face of praxis, on the processes of "learning to teach" which involves continuous training. DiscussionThis perspective points to the development of certain skills that are developed over time of the formation through diverse strategies Conclusionsthe development of the professional competences of the teacher that confront with the disciplinary approach from an innovative glance

Bioconversion of Oil Palm Trunk Residues Hydrolyzed by Enzymes from Newly Isolated Fungi and Use for Ethanol and Acetic Acid Production Under Two-Stage and Simultaneous Fermentation

Oil palm trunk (OPT) is one of the richest biomass in Southern Thailand. The OPT residues (OPTr), obtained after separation of the sap, was hydrolyzed by the crude enzymes of the selected fungal isolates under solid-state fermentation (SSF) and submerged fermentation (SmF). From screening and identification studies, Ceratocystis paradoxa TT1 produced the highest CMCase activity (18.16 Unit gds−1) from SmF while Trichoderma koningiopsis TM3 exhibited the highest xylanase and FPase activities (56.46 and 2.13 Unit gds−1, respectively) from SSF. Enzymatic hydrolysis of OPTr using the crude enzymes of T. koningiopsis TM3 (25 Unit gds−1) at 50 °C for 15 h revealed the maximum reducing sugars of 11.92 g L−1 with the yield of 0.48 gg−1. Bioconversion of the OPTr hydrolysate to ethanol by Saccharomyces cerevisiae TISTR5055 could be increased (2.13-fold) by supplementation of YM nutrients. The effects of co-cultures (S. cerevisiae TISTR5055 and Acetobacter aceti) for production of co-products (ethanol and acetic acid) from the OPTr hydrolysate with and without YM nutrients addition was conducted under two-stage fermentation and simultaneous fermentation. Both fermentation types gave similar ethanol production (4.15 and 4.01 g L−1) but the ethanol productivity (0.34 g L−1 h−1) from two-stage fermentation was 1.55-fold higher than that from simultaneous fermentation. On the other hand, the maximum acetic acid production (2.12 g L−1) and productivity (0.09 g L−1 h−1) were achieved from the simultaneous fermentation of the co-cultures without nutrient addition. These two values were 1.7-fold higher acetic acid concentration and 4.4-folds higher productivity than the two-stage fermentation.

Stern–Geary Constant for X80 Pipeline Steel in the Presence of Different Corrosive Microorganisms

The Stern–Geary constant (B value) is indispensable to measure the corrosion rate in the microbiologically influenced corrosion (MIC) systems. Linear polarization resistance (LPR) and weight loss methods were used to study the variation of B values for X80 pipeline steel in the presence of Pseudomonas aeruginosa, Acetobacter aceti and Desulfovibrio vulgaris. The results showed that B values in the presence of three different bacteria were 35.60 ± 0.55 mV, 33.00 ± 1.00 mV and 58.60 ± 0.55 mV, respectively, suggesting that the change of corrosion system significantly affected the B values of X80 pipeline steel. This work further indicated that the determination of B values is necessary to accurately measure the MIC rate by LPR method.

Suitability of ultraviolet‐C irradiation for white grape must

Background and Aims Ultraviolet (UV)‐C irradiation is used for the reduction of microbial spoilage in food. Its effectiveness for the treatment of white grape must has been investigated considering different microbial species and modification of must composition. Methods and Results Static and dynamic laboratory‐scale systems emitting at 254 nm were used for the treatment of Vitis vinifera cv. Chardonnay and cv. Crimson grape juices of variable turbidity. The must samples were singularly inoculated with a pure culture of wine spoilage strains belonging to three species, Dekkera bruxellensis, Acetobacter aceti and Lactobacillus brevis, and treated with UV‐C ranging from 300 to 1800 J/L. Cell counts and microbial reduction (derived from α values, according to the Weibull model), colour change, polyphenol oxidase (PPO) inactivation and formation of α‐dicarbonyl compounds were evaluated. After treatment at the maximum UV‐C dosage under static conditions, reductions of yeast counts of 4.91–5.99 log10 colony‐forming units (CFU)/mL and bacterial counts of 4.12–5.05 log10 CFU/mL were achieved, depending on the strain being tested. Polyphenol oxidase activity decreased by up to 7.8 ± 1.4% with variation attributed to must turbidity, which indicated that clarification of must before UV‐C treatment can lead to PPO inactivation. No significant variation in the colour or the concentration of α‐dicarbonyl compounds was detected. Results were confirmed for grape juice with the continuous flow apparatus. Conclusions The UV‐C systems achieved microbial reduction without formation of oxidative compounds, suggesting that the experimental conditions employed did not cause any noticeable oxidative phenomena. Significance of the Study The UV‐C treatment of grape juice can be considered a potential alternative to sulfur dioxide addition for processing of white must. Improved efficacy of treatment can be achieved by increasing the flow rate and by clarification of must, making the system potentially applicable under industrial conditions.

Bioprocess Intensification Using Flow Reactors: Stereoselective Oxidation of Achiral 1,3-diols with Immobilized Acetobacter Aceti

Enantiomerically enriched 2-hydroxymethylalkanoic acids were prepared by oxidative desymmetrisation of achiral 1,3-diols using immobilized cells of Acetobacter aceti in water at 28 °C. The biotransformations were first performed in batch mode with cells immobilized in dry alginate, furnishing the desired products with high molar conversion and reaction times ranging from 2 to 6 h. The biocatalytic process was intensified using a multiphasic flow reactor, where a segmented gas–liquid flow regime was applied for achieving an efficient O2-liquid transfer; the continuous flow systems allowed for high yields and high biocatalyst productivity.