Culture and function-related characteristics of six acetic acid bacterial strains isolated from farm-made fermented vinegars

Abstract

The present study evaluated the cultural and functional characteristics of six strains of acetic-acid bacteria (AAB), namely, GHUR-A11-2, SR-A24, GY-A26, GHF-A37, JS-B7, and JS-C1, which were isolated from farm-made fermented vinegars. The six bacterial strains exhibited high acetic acid production capability via the decomposition of CaCO 3 , and they were identified as Acetobacter pasteurianus based on the 16S rDNA sequences. The initial pH and optimal growth temperature for acetic acid production were determined to be 4.0 and 30℃, respectively; however, some strains of AAB presented reasonable growth even at 40℃. Four bacterial strains (except SR-A24 and GHF-A37) exhibited alcohol degradation activities of more than 90%. Bacillus cereus presented high susceptibility to the antibacterial activity of the six strains of AAB. The antioxidant activity evaluated using DPPH and ABTS was 5-15 times and 4-5 times higher for the six strains of AAB than that for the control group, respectively. GHUR-A11-2, SR-A24, and JS-C1 exhibited higher ACE activities, with inhibition rates of 154%-175%, as compared to those exhibited by the positive control of 0.1% captopril (inhibition rate of 138%). Furthermore, the fibrinolysis activity of SR-A24 (93.3%) was markedly higher than that of 0.5 U plasmin. Four bacterial strains (except GHF-A37 (75.3%) and JS-B7 (68.0%)), exhibited α-glucosidase inhibition activities of more than 100%. It was concluded that the six strains of AAB exhibited excellent physiologically active characteristics, which facilitated their use as seed strains for the synthesis of high-efficiency functional vinegar by harnessing the functional characteristics that fit the scientific basis.

Quality and Functional Characterization of Acetic Acid Bacteria Isolated from Farm-Produced Fruit Vinegars

“…The AAB strains were isolated from farm-produced vinegars (Table 1) by plating on YGC agar (5 g/L yeast extract, 30 g/L glucose, 10 g/L CaCO3, 4% (v/v) ethanol, 2% (w/v) agar) [22]. Each 100-200 µL sample of vinegars was spread onto YGC agar plates and incubated at 30 °C for 3 days.…”

“…Antioxidant activity for AAB strains was determined using 2,2-diphenyl-1picrylhydrazyl (DPPH, Sigma-Aldrich, St Louis, MO, USA) and 2,2′-azino-bis-(3ethylbenzothiazoline-6-sulfonic acid) (ABTS, Sigma-Aldrich). Determination of radical scavenging activity of the samples was carried out using a previously reported method [22,25] with slight modifications. For the DPPH assay, a stock solution of 0.4 mM DPPH in absolute ethanol was prepared, and a working DPPH solution was prepared by dilution with absolute ethanol to an absorbance of 0.95-0.99 at 525 nm.…”

Immunomodulatory effects of six Acetobacter pasteurianus strains in RAW-Blue macrophage

“…In this study, we evaluated the immune response of six strains of AAB, which were isolated from farm-made fermented vinegars and recently characterized with excellent physiological functions, including antibacterial, antioxidant, antihypertensive and antidiabetic effects (Kim et al, 2022). We suggest that the expression of pro-inflammatory genes inducible NO synthase (iNOS), cyclooxygenase (COX)-2, TNF-α, IL-6, and IL-1β, regulated the production of NO and cytokines through AABstimulated NF-κB and AP-1 activation.…”

“…The six strains of AAB used in this study are : A. pasteurianus A11-2 (GHUR-A11-2, KACC 92203P) originating from vinegar of brown rice, A. pasteurianus A24 (SR-A24, KACC 92204P) originating from rice vinegar, A. pasteurianus A26 (GY-A26, KACC 92205P) originating from fruit vinegar of Yeongcheon, Gyeongbuk, Korea, A. pasteurianus A37 (GHF-37, KACC 92206P) originating from plum vinegar, A. pasteurianus B7 (JS-B7, KACC 92207P) originating from grain vinegar of Sunchang, Jeonbuk, Korea, and A. pasteurianus C1 (JS-C1, KACC 92208P) originating from fruit vinegar of Chuncheon, Gangwon, Korea. These strains were isolated, reported and stored in the Fermented Processed Foods Division of the National Academy of Agricultural Sciences (Kim et al, 2022). The AAB were cultured at 30℃ using a solid (yeast extract 0.5%, glucose 3.0%, CaCO 3 1.0%, agar 2.0%, and ethanol 3%, w/v) and liquid media (yeast extract 0.5%, glucose 0.5%, glycerol 1.0%, MgSO 4 ․7H 2 O 0.02%, ethanol 4.0%, and acetic acid 1.0%, w/w).…”

Microbiome Analysis of Traditional Grain Vinegar Produced under Different Fermentation Conditions in Various Regions in Korea

“…Traditional vinegar is a fermented food produced by various microorganisms under complex conditions [ 1 ]. Vinegar is used worldwide as an important cooking ingredient and as a preservative [ 2 , 3 , 4 ]. Due to its organic acid, polyphenol, and melanoidin content, traditional vinegar has various physiological functions, including blood glucose control, lipid metabolism regulation, weight loss, antimicrobial, antioxidant, and anticancer activities [ 5 ].…”