• Journal of Microbiology and Biotechnology
• /
• 제26권6호
• /
• pp.1057-1062
• /
• 2016

Kimchi is a traditional Korean fermented vegetable food, the production of which involves brining of Korean cabbage, blending with various other ingredients (red pepper powder, garlic, ginger, salt-pickled seafood, etc.), and fermentation. Recently, kimchi has also become popular in the Western world because of its unique taste and beneficial properties such as antioxidant and antimutagenic activities, which are derived from the various raw materials and secondary metabolites of the fermentative microorganisms used during production. Despite these useful activities, analysis of the microbial community present in kimchi has received relatively little attention. The objective of this study was to evaluate the bacterial community structure from the raw materials, additives, and final kimchi product using the culture-independent method. Specifically, polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) was used to analyze the 16S rRNA partial sequences of the microflora. One primer set for bacteria, 341F^GC-518R, reliably produced amplicons from kimchi and its raw materials, and these bands were clearly separated on a 35-65% denaturing gradient gel. Overall, 117 16S rRNA fragments were identified by PCR-DGGE analysis. Pediococcus pentosaceus, Leuconostoc citreum, Leuconostoc gelidum, and Leuconostoc mesenteroides were the dominant bacteria in kimchi. The other strains identified were Tetragenococcus, Pseudomonas, Weissella, and uncultured bacterium. Comprehensive analysis of these microorganisms could provide a more detailed understanding of the biologically active components of kimchi and help improve its quality. PCR-DGGE analysis can be successfully applied to a fermented food to detect unculturable or other species.

• 한국미생물·생명공학회지
• /
• 제49권2호
• /
• pp.131-137
• /
• 2021

This study aimed at isolating lactic acid bacteria with anti-MRSA (methicillin-resistant Staphylococcus aureus) bacteriocin activity from fermented shrimp. We selected three strains, named Weissella sp. S1, S2, and S3, using analysis based on 16S rRNA gene sequences. All strains showed appropriate growth in an MRS medium containing 5% (w/v) NaCl and showed antibacterial activities against Bacillus cereus, Escherichia coli, Staphylococcus aureus, and MRSA. The strains exhibited similar growth rates at 0-5% NaCl, with approximate reduction in growth rate observed at 9% NaCl. Weissella sp. S1, S2, and S3 exhibited maximum growth rates at pH 7, 9, and 8, respectively. The crude bacteriocin was prepared from Weissella sp. S3 and subjected to characterization. The remaining activities after 30 min of exposure at each temperature were 100%, beyond 75%, and 49% at 4℃ and 37℃, 50℃ and 70℃, and 100℃, respectively. The remaining activities after 24 h of exposure at each pH were 100%, 75%, and 49% at pH 3 and 5, 7 and 9, and 10, respectively. Use of 50% (v/v) ethanol or isopropanol treatment did not diminish the antibacterial activity of the bacteriocin, while the 50% (v/v) hexane treatment reduced the activity by 51%. The molecular weight of the bacteriocin was nearly 6 kDa that was quantified using tricine-SDS-PAGE. Our findings suggest that Weissella sp. S3 may be considered a probiotic and useful source of antimicrobial substances in the development of bio-preservatives for food or in MRSA treatment.

• 한방비만학회지
• /
• 제18권2호
• /
• pp.96-105
• /
• 2018

Objectives: The aim of this study was to examine the effect of Asparagus cochinchinensis (AC) and fermented AC (fAC) on microorganisms and efficacies. Methods: AC was fermented for four weeks without using any bacterial strains. Then we investigated fermentation characteristics including potential of hydrogen (pH), total sugar, microbial profiling and antioxidant compound contents such as total polyphenol and total flavonoid. The anti-obesity effects of AC and fAC were evaluated by using Oil Red O staining in 3T3-L1 adipocyte. Also anti-diabetic effects of them were evaluated by using 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose (2-NBDG) uptake in C2C12 skeletal muscle cell. Results: Both pH and total sugar of fAC were decreased significantly compared to unfermented AC. And the abundance of total bacteria and lactic acid bacteria increased during fermentation, especially Lactobacillus plantarum. Also fermentation of AC increased the content of total polyphenol. On the metabolic aspects, we found that AC and fAC suppressed fat accumulation. Conclusions: After four weeks of fermentation, AC increased concentrations of active compounds, altered microbial composition, and inhibited fat accumulation such as triglyceride. These results indicate that fermentation of AC might be a beneficial therapeutic approach for obesity.

• 한국응용과학기술학회지
• /
• 제37권6호
• /
• pp.1535-1544
• /
• 2020

본 연구의 목적은 3년 이상 숙성된 재래식 된장으로부터 아민 산화 효소를 생산하는 프로바이오틱 바실러스균을 분리 동정하는 것이다. 시료로부터 분리된 바이오제닉 아민(biogenic amines, BA) 생성균은 Bacillus sp. TS09, Bacillus licheniformis TS17, Bacillus subtilis TS19, Bacillus cereus TS23, Bacillus sp. TS30, Bacillus megaterium TS31, B. subtilis TS44, Bacillus coagulans TS46 및 Bacillus amyloliquefaciens TS59 등으로 동정되었다. 한편 동일한 시료로부터 분리된 B. subtilis TS04와 TS50은 인공 위액 및 담즙액에 대한 저항성, 장내 상피세포에 대한 부착능 및 BA 생성균(Bacillus sp. TS30 및 B. subtilis TS44)에 대한 박테리오신 생산 등의 프로바이오틱 활성을 나타내었다. 게다가 B. subtilis TS04와 TS50 균주가 생산한 아민 산화 효소에 의하여 카다베린, 푸트레신 및 티라민의 생성량을 감소시킬 수 있었으므로 이들은 BA 중독 위험을 낮출 수 있는 프로바이오틱스 소재로서의 활용 가치가 높을 것으로 판단된다.

• Journal of Plant Biotechnology
• /
• 제49권3호
• /
• pp.250-256
• /
• 2022

This study was conducted to measure changes in polyphenol components and antioxidant effects of Cirsium Lineare (Thunb.) after fermentation by lactic acid bacteria. First, Cirsium Lineare (Thunb.) extract (CE, unfermented) and Cirsium Lineare (Thunb.) extract fermented with Lactobacillus paracasei (FCE) were prepared. Changes in components resulting from fermentation were confirmed through changes in polyphenol compound content and silymarin derivative pattern, and antioxidant activity was confirmed using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, 2,2'azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, and ferric reducing antioxidant power (FRAP) analyses. As a result, polyphenol contents of CE and FCE were confirmed as 21.94 ± 1.15 and 67.90 ± 4.48 mg GAE/g, respectively. Both values were increased approximately three times by fermentation, and there was also a change in the silymarin derivative pattern. In the case of DPPH radical RC₅₀ values in particular, CE and FCE were confirmed to inhibit DPPH radicals by 50% at concentrations of 129.44 ± 5.85 and 50.00 ± 3.47 ㎍/mL, respectively, with the FCE value approximately 2.5 times lower than that of CE. In addition, ABTS radical scavenging and FRAP activity were confirmed to share similar trends as DPPH radical scavenging activity. When CE and FCE were compared, FCE showed a better antioxidant effect overall. In conclusion, this study suggested that FCE prepared through lactic acid bacteria fermentation may be utilized as a powerful antioxidant material.

• 한국축산식품학회지
• /
• 제43권3호
• /
• pp.454-470
• /
• 2023

This study analyzed the microbiological (Lactobacillus spp., Staphylococcus spp., mold, yeast, aerobic bacteria) and physicochemical properties [pH, salinity, water activity, volatile basic nitrogen (VBN), and thiobarbituric acid reactive substances]. The starters were used by mixing Debaryomyces hansenii separated from Korean Doenjang (D) and fermented sausage (S). The starter was inoculated with dry-cured ham and aged for 6 weeks at 20℃ and 25℃, respectively. The aerobic bacteria, Lactobacillus spp., and Staphylococcus spp. of D, S, and DS treatment showed significantly higher values at 25℃ than at 20℃. Among them, S25 treatment showed a high tendency. At week 6, the mold of the S25 treatment was significantly higher than the S20 treatment, and the yeast was higher in 25℃ than 20℃ (p<0.05). The pH of all treatment groups increased with the aging period. Compared with that at 25℃, the pH was significantly higher at 20℃ (p<0.05). The water activity showed a significant decrease as the aging period increased, and the treatment of D25, S20, and DS20 showed a significantly higher value at week 6 (p<0.05). Compared with that at 20℃, the VBN content was higher at 25℃. At week 6, the VBN contents of the C20, S25, and DS25 groups were higher than those of the other treatment groups. Therefore, inoculation of D. hansenii separated from fermented sausage produced in Korean starter at 25℃ is expected to improve the safety of harmful microorganisms and physiochemical properties in dry-cured ham.

• 한국축산식품학회지
• /
• 제43권2호
• /
• pp.346-358
• /
• 2023

The aim of this study was to evaluate efficacies of selected lactic acid bacteria (LAB) in inducing immunoglobulin A (IgA) secretion. Twenty-five different LAB isolated from traditional fermented Korean foods were characterized for their probiotic properties and screened to identify those that could stimulate lamina propria cells (LPCs) from Peyer's patch to secret IgA in vitro. Among them, four strains (Lactiplantibacillus plantarum CJW55-10, Lactiplantibacillus pentosus CJW18-6, L. pentosus CJW56-11, and Pediococcus acidilactici CJN2696) were found to be strong IgA inducers. The number of IgA positive B cells and soluble IgA level were increased when LPCs were co-cultured with these LAB. Expression levels of toll-like receptor (TLR) such as TLR2 and TLR4 and secretion of interleuckin-6 were augmented in LPCs treated with these LAB. Further, we determined whether oral intake of these LAB enhanced IgA production in vivo. After one-week of daily oral administration, these LAB feed mice increased mucosal IgA and serum IgA. In conclusion, selected strains of LAB could induce systemic IgA secretion by activating lamina propria B cells in Peyer's patch and oral intake of selected strains of LAB can enhance systemic immunity by inducing mucosal IgA secretion.

• 한국미생물·생명공학회지
• /
• 제51권2호
• /
• pp.191-202
• /
• 2023

Elevated serum cholesterol is a main risk factor for heart disorders. Most probiotic products administered to lower cholesterol are dairy products which are not suitable for lactose-intolerant individuals. In this study, we assessed the cholesterol-lowering efficacy of LAB isolated from traditionally fermented drinks in diet-induced rats and determine their efficacy in the production of non-dairy, probiotic formulations using papaya juice. LAB were isolated from palm wine and corn beer on MRS agar using a pour-plate technique. Identification was carried out using 16S rRNA gene sequencing. A hypercholesterolemia model in which diet-induced Wistar albino rats were assigned into four groups was established. Oral gavage was carried out for 30 days. On the 31^st day, the rats were dissected and the serum lipid profile was analyzed using biochemical kits. A 10⁶ cfu/ml of a 24-h-old culture of selected lactobacilli was used to inoculate papaya juice and incubated at 37℃. Microbial and chemical changes were assessed during papaya fermentation and after four weeks of cold storage. Two selected isolates (Pw1 and Cb4) had in vitro cholesterol reduction of > 80%. These two isolates lowered lipid profile (triglyceride, total cholesterol, LDL-c) significantly, and increased HDL-c levels (p < 0.5) in the rat sera. Phylogenetic analysis showed that Pw1 was 98.86% similar to Limosilactobacillus fermentum, while Cb4 was 99.54% similar to Enteroccocus faecium. Both strains fermented papaya juice with cell viability reaching 8.92 × 10⁸ cfu/ml and 25.3 × 10⁸ cfu/ml respectively, and were still viable after 4 weeks of cold storage.

• Animal Bioscience
• /
• 제35권9호
• /
• pp.1379-1389
• /
• 2022

Objective: This study identified the major lactic acid bacteria (LAB) strains from different fermented total mixed rations (FTMRs) via metataxonomic analysis and evaluated the ability of their standard strain as ensiling inoculants for corn stover silage. Methods: The bacterial composition of eight FTMRs were analyzed by 16S rDNA sequencing. Corn stover was ensiled without LAB inoculation (control) or with 1×10⁶ cfu/g LAB standard strain (Lactobacillus vaginalis, Lactobacillus reuteri, Lactobacillus helveticus, or Lactobacillus paralimentarius) selected from the FTMRs or 10 g/t commercial silage inoculant (CSI) around 25℃ for 56 days. For each inoculation, a portion of the silage was sampled to analyze ensiling characteristics at time intervals of 0, 1, 3, 7, 14, 28, and 56 days, gas production (GP), microbial crude protein and volatile fatty acids as the measurements of rumen fermentation characteristics were evaluated in vitro with the silages of 56 days after 72 h incubation. Results: Lactobacillus covered >85% relative abundance of all FTMRs, in which L. pontis, L. vaginalis, L. reuteri, L. helveticus, and L. paralimentarius showed >4% in specific FTMRs. CSI, L. helveticus, and L. paralimentarius accelerated the decline of silage pH. Silage inoculated with L. paralimentarius and CSI produced more lactic acid the early 14 days. Silage inoculated with L. paralimentarius produced less acetic acid and butyric acid. For the in vitro rumen fermentation, silage inoculated with CSI produced more potential GP, isobutyric acid, and isovaleric acid; silage inoculated with L. helveticus produced more potential GP and isovaleric acid, silage inoculated with L. paralimentarius or L. reuteri produced more potential GP only. Conclusion: The standard strain L. paralimentarius (DSM 13238) is a promising ensiling inoculant for corn stover silage. The findings provide clues on strategies to select LAB to improve the quality of silage.

• 급식외식위생학회지
• /
• 제5권1호
• /
• pp.30-39
• /
• 2024

Rice, nuruk, and water are the main ingredients to prepare takju, a traditional Korean liquor. Takju quality varies depending on the type of ingredients and fermentation temperature. In the current study, different combinations of nuruk (SH, JJ) and rice (glutinous rice, non-glutinous rice) were fermented at different temperatures (20, 25℃) and analyzed for quality characteristics over the fermentation period of 10 days. Regardless of the temperature, higher soluble solids (27.1~29%) were measured in the takju prepared with glutinous rice compared to non-glutinous rice. And acidity increased from 0.03% to 1.1% to all takju fermented at both 20 and 25℃, and, higher acidity was measured in the takju prepared with JJ nuruk. The color value of lightness (L) decreased from 57.9 to 23.9. Alcohol content was less than 15.5% in glutinous rice takju and less than 12.3% in non-glutinous rice takju. Total bacteria count (7~8 Log CFU/mL) and lactic acid bacteria count (4~7 Log CFU/mL) increased in different takju. However, the very high yeast count was recorded in takju prepared from SH nuruk compared to takju prepared from JJ nuruk at 0 day of fermentation. A sharp decline (84.92~98.57%) of yeast was observed just after the 1st day of fermentation which gradually reduced to lowest at 4th day of fermentation. No yeast was observed at 6th day fermentation and onwards. These results indicate that the raw materials, especially rice and nuruk, affect the physiochemical properties of takju.