• Microbiology and Biotechnology Letters
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• v.46 no.4
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• pp.403-415
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• 2018

The aims of this novel work were to determine the microbial strains and exopolysaccharide (EPS) producers in water kefir from Nakhon Ratchasima Province, Thailand. Thirty-three microbial strains were identified using 16S rRNA gene analysis consisting of 18 bacterial strains, as 9 strains of acetic acid bacteria (AAB), 9 strains of lactic acid bacteria (LAB), and 15 yeast strains. All bacteria were able to produce EPS with a diverse appearance on agar media containing different sugars at a concentration of 8%. Culture supernatants from AAB and LAB showed 31-64% 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity with the highest antioxidant activity of 64% from Acetobacter pasteurianus WS3 and WS6. Crude EPS from A. pasteurianus WS3 displayed the highest ferric reducing antioxidant power at 280 mM $FeSO_4/g$ EPS, greatest anti-tyrosinase activity at 20.35%, and highest EPS production of 1,505 mg EPS/L from 8% sucrose. These microbes offer beneficial health implications and their EPSs can be used as food additives and cosmetic ingredients.

• Food Science and Preservation
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• v.30 no.4
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• pp.691-702
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• 2023

This study aimed to develop high value-added mulberry (Morus alba) vinegar by fermenting mulberry with yeast and acetic acid bacteria, for using it in various foods. To select the optimal strain for mulberry fermentation, different strains were tested and Saccharomyces cerevisiae SRCM101756 and Acetobacter pasteurianus SRCM102419, exhibiting excellent alcohol and acetic acid production ability during mulberry fermentation, were selected for fermentation. Mulberry vinegar was prepared using mulberry wine and the selected acetic acid bacteria, and the physicochemical properties and physiological effects were measured. The pH was 2.98 and total acidity was 4.70% by day 9 of fermentation, establishing the possibility of developing them into vinegars for industrial use. The angiotensin-glucosidase inhibition activity of mulberry vinegar increased from 13.22% to 19.19% in the 100-fold dilution, and from 42.35% to 46.11% in the 50-fold dilution, from before fermentation to after fermentation, respectively. The angiotensin-converting enzyme inhibition activity of mulberry vinegar was found to significantly increase from 44.82% before fermentation to 63.88% after fermentation in the 25-fold dilution. Moreover, a significant increase in pancreatic lipase inhibition activity after fermentation was observed. Thus, mulberry vinegar can be used as a functional material in vinegar and other foods.

• Microbiology and Biotechnology Letters
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• v.43 no.2
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• pp.97-104
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• 2015

Vinegar is a widely used acidic seasoning and can be manufactured using various methods and bases, including cereals, wheat, and fruits. Most studies on vinegar have been conducted to evaluate its antioxidant activity. In the present study, fermented dark vinegar (FDV) produced from unpolished rice was examined for its antimicrobial activity, biochemical content, including the amounts of sugar, total soluble sugar, organic acid, and free amino acids, and pH and physiological activity. The antimicrobial efficiency of FDV was assessed using the paper disc-agar diffusion method. FDV exhibited strong antimicrobial activity against the pathogenic bacteria and yeast strains that were tested. In fact, the activity of FDV was shown to be higher than that of the commercial antibiotics carbenicillin (50 µg/ml) and tetracycline (50 µg/ml) against Staphylococcus aureus, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella typhimurium, Yersinia enterocolitica, and Lodderomyces elongisporus. The antioxidant activity of FDV and ascorbic acid was evaluated. Using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method, we found that FDV has the highest activity of the antioxidants. After spreading FDV onto tryptic soy broth and yeast extract-peptone-dextrose agar media, the microbial strains were isolated and characterized through physiological and biochemical analysis. Based on 16S ribosomal DNA sequence analysis, the isolated microorganisms exhibited a close similarity to Acetobacter papayae, Acetobacter pasteurianus, and Acetobacter peroxidans.

• Microbiology and Biotechnology Letters
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• v.48 no.2
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• pp.193-204
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• 2020

Sixteen acetic acid bacteria (AAB) were isolated from blueberries and citric fruits of the Salto Grande region (Concordia, Entre Rios, Argentina) using enrichment techniques and plate isolation. Enrichment broths containing ethanol and acetic acid enabled maximum AAB recovery, since these components promote their growth. Biochemical tests allowed classification of the bacteria at genus level. PCR-RFLP of the 16S rRNA and PCR-RFLP of the 16S-23S rRNA intergenic spacer allowed further classification at the species level; this required treatment of the amplified products of 16S and 16S-23S ITS ribosomal genes with the following restriction enzymes: AluI, RsaI, HaeIII, MspI, TaqI, CfoI, and Tru9I. C7, C8, A80, A160, and A180 isolates were identified as Gluconobacter frateurii; C1, C2, C3, C4, C5, C6, A70, and A210 isolates as Acetobacter pasteurianus; A50 and A140 isolates as Acetobacter tropicalis; and C9 isolate as Acetobacter syzygii. The bacteria identified by 16S rRNA PCR-RFLP were validated by 16S-23S PCR-RFLP; however, the C1 isolate showed different restriction patterns during identification and validation. Partial sequencing of the 16S gene resolved the discrepancy.

• Food Science and Preservation
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• v.21 no.6
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• pp.903-907
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• 2014

For the selection of a starter for vinegar, six strains of acetic-acid bacteria were isolated from traditional Korean vinegar fermented through the static method. These strains were investigated for their acetic-acid fermentation and identification characteristics. The 16S rRNA sequences of six strains were identified as Acetobacter pasteurianus, A. malorum, Gluconacetobacter entanii, Ga. intermedius, and Ga. xylinus respectively. The overoxidation of acetic acid, acetic-acid and pH tolerances, and acetic-acid production of these strains were investigated. None seemed to have been overoxidized. The Gluconacetobacter genus showed acetic-acid tolerance. Among the acetic-acid bacteria, A. malorum V5-7 exhibited the highest pH tolerance. The Ga. intermedius V11-5 and Ga. xylinus V8-1 strains produced colloids that exopolysaccharides of fiber. The acetic-acid production by isolated acetic-acid bacteria and type strain was a achieved at a shaking culture at $30^{\circ}C$ for 5 days. A. malorum V5-7, A. pasteurianus Gam2, and Ga. intermedius V11-5 exhibited the highest acetic acid production. The study results indicate that appropriate strains of acetic-acid bacteria improved the thraditional Korean vinegar fermented through the static method.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.2
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• pp.298-305
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• 2016

Prior research has attempted to develop a method for fermentation of onion vinegar to satisfy customer quality standard. Onion wine (OW) and onion vinegar (OV) were produced by alcoholic and acetic fermentation of onion extracts (OE) using Saccharomyces cerevisiae and Acetobacter pasteurianus, and their taste compounds (non-volatile organic acids, non-protein N compounds, and free sugars) were determined. Main components of non-volatile organic acids were malic acid (50.1%) and citric acid (26.9%) in OE, whereas malic acid (28.1%), acetic acid (20.8%), lactic acid (20.1%), citric acid (13.3%), and succinic acid (12.0%) were detected in OW. Total concentrations of non-volatile organic acids in OV were 4,612.0 mg/100 g, which was 3.9 and 2.3 times higher than those of OE and OW, respectively. Non-volatile organic acids except malonic acid and acetic acid were reduced during acetic fermentation. Non-protein N compounds increased 4.23-fold ($41,526.8{\mu}g/100g$) during alcohol fermentation, and urea content was the highest of non-protein N compounds at $33,816{\mu}g/100g$. The reduced values in OV might be used as a nutritious element of Acetobacter pasteurianus. Free sugars (glucose, fructose, and sucrose) were detected in OE, whereas only fructose was absent in OW and OV.

• Korean Journal of Food Science and Technology
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• v.53 no.6
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• pp.768-774
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• 2021

Habanero red pepper (HRP)-fermented liquid with Acetobacter pasteurianus SRCM101474 was prepared, the quality characteristics measured and bioactivity analysis were measured. As the fermentation period increased, the number of viable cells increased, pH decreased, and acidity increased. After fermentation, the organic acid content of HRP was confirmed to be acetic acid with the highest content of 33413.54 ppm. Analysis of capsaicin and dihydrocapsaicin showed that the increase was significantly raised as acetic acid fermentation progressed. The total phenol and flavonoid contents as well as the antioxidant activity increased as the fermentation period passed. In addition, α-glucosidase inhibitory and pancreatic lipase inhibitory activities were significantly increased after fermentation. It was confirmed that it can be used as a functional material by measuring the physiological activities of antioxidant, anti-obesity, and anti-diabetes through fermentation, and the possibility of development as a spicy material and application product using it as capsaicin increases after fermentation.

• Korean Journal of Food Science and Technology
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• v.50 no.1
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• pp.61-68
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• 2018

The aim of this study was to develop various types of vinegar using whey. Amongst various acetic acidproducing strains, Acetobacter pomorum IWV-03 strain was selected as an excellent strain for the production of whey makgeolli vinegar. The acidity of this vinegar was found to be 5.6%. The total organic acid content and the free amino acid content of the whey makgeolli vinegar were 5.5 and 5.9 mg%, respectively, which was higher than that of the control makgeolli vinegar (5.0 and 4.5 mg%, respectively). In addition, DPPH and ABTS radical scavenging activity of whey makgeolli vinegar were 49.85 and 63.46%, respectively, which were again higher than that of control makgeolli vinegar (27.20 and 19.22%, respectively).

• Journal of Dairy Science and Biotechnology
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• v.40 no.1
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• pp.23-34
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• 2022

In this study, to determine the importance of lactic acid bacteria (LAB) in Kombucha fermentation, biological functions, such as organic acid production and anti-inflammatory and antibacterial activities, of Kombucha, with or without LAB inoculation, were evaluated. Lactobacillus paracasei DK215, Saccharomyces cerevisiae C3, and Acetobacter pasteurianus P2 were selected as the inoculants. Organic acids were measured every 3 days from the end of fermentation using HPLC; the organic acid content of LAB-inoculated Kombucha was relatively high. Samples with or without LAB inoculation showed high antibacterial activity against Escherichia coli. The MTT assay results indicated no significant difference in concentration difference and cell death. In the NO production test, compared with the uninoculated Kombucha sample, the LAB-inoculated Kombucha sample exhibited a value similar to that of the group without LPS treatment. The levels of cytokine (IL-1α, IL-6, TNF-α) production were significantly lower than those of the LPS(+) group, indicating the anti-inflammatory activity potential of the Kombucha sample. This improvement in the biological function of the LAB-inoculated Kombucha further verifies the value of LAB in the fermented food and beverage industry.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.6
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• pp.695-702
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• 2017

This study was carried out to investigate the effects of seed vinegar on antioxidant activity and antimicrobial activities of concentrated blueberry vinegar (CBV). Of the nine strains of yeast and six strains of acetic acid bacteria provided by the Microbial Institute for Fermentation Industry, each strain of yeast (Saccharomyces cerevisiae SRCM 100610, showing the highest ethanol content) and acetic acid bacteria (Acetobacter pasteurianus SRCM 101342, showing the highest total acidity) was selected for production of CBVs. Sugar content, pH, total acidity, total phenolic content (TPC), and browning intensity (280 nm and 420 nm) in CBVs using concentrated blueberry juice were $11.05{\sim}12.70^{\circ}Brix$, 2.63~2.98, 1.65~5.72%, 3.03~4.24 mg/mL, 0.95~1.50, and 0.11~0.20, respectively. Sugar content and total acidity of CBVs increased upon addition of seed vinegar, whereas pH, TPC, and browning intensity decreased. Of all CBVs with various additions of seed vinegar, the control showed the lowest $EC_{50}$ values in DPPH radical scavenging assay, ABTS radical scavenging assay, and reducing power (23.80, 19.48, and 79.21 dilution factor, respectively), whereas the 40% seed vinegar group showed the highest clear zone diameter values for Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, and Bacillus cereus (4.31, 4.59, 5.81, and 3.97, respectively). Antioxidant activities of CBVs were closely correlated with their TPC, browning intensity at 280 nm, pH, and total acidity values, showing correlation determination coefficient ($R^2$) values higher 0.82. However, antimicrobial activities of CBVs were closely correlated with their pH and total acidity values, showing higher $R^2$ values more than 0.92. These results suggest that CBVs using concentrated blueberry juice, S. cerevisiae SRCM 100610, and A. pasteurianus SRCM 101342 may be useful as potentially functional foods for enhancing health.