• Preventive Nutrition and Food Science
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• 제2권2호
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• pp.109-120
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• 1997

In order to elucidate roles of lactic acid bacteria(LAB) for the antibiosis occurring in th fermenting environment of Kimchi, 2.052 strains of LAB were isolated from Kimchi. Fifty tow strains which showed antagonistic effect against 4 indicator strains were finally selected and investigated. Based upon responses to protease treatment, antibiosis of the 52 strains of LAB were classified into 3 types. Type A antibiosis resulted from action of antibiotic-like substances which were not affected by protease treatment and which had broad action spectra against even natural inhabitants of Kimchi. Type B antibiosis was due to bacteriocin-like substances which were very sensitive to treatment of protease and more effective against foreign bacteria than original inhabitant microflora. Type C antibiosis was owing to proteinaceous compounds which were activated or induced by the presence of protease and then exerted antibacterial activities. Therefore, lactic acid bacteria appeared to contribute to antibiosis of Kimchi by the concerted action of these three different types of antibacterial compounds. As one of model system for type B bacteriocin, the antagonistic compound produced by LAB31-9 as well as th producer strain itself was further charaacterized. Strain LAB31-9 was identified as L. casei. Bacteriocin produced by LAB31-9 was proteinaceous and stable over wide range of pH and to various solvents, but very labile to heat treatment. Its mode of action was bactericidal. Based upon these data, bacteriocin produced by LAB31-9 was named as 'caseicin K319'. Genetic determinant for the bacteriocin production of LAB31-9 was located in the chromosome.

• 산업식품공학
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• 제13권2호
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• pp.130-137
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• 2009

This study evaluated the potential of utilizing the osmotic solution from dried mango processing as alternative raw material for mango wine making. Fermentation was carried out using two kinds of yeast strains Saccharomyces bayanus, Lalvin EC-1118 and Saccharomyces cerevisiae, Lalvin D-47 at 20$^{\circ}C$ for 28 days. Physicochemical analysis during fermentation was performed for each treatment and the resulting wine samples were analyzed for color, volatiles and sensory properties. Results of physicochemical analysis between the two fermenting samples as well as the wine samples show almost similar results regardless of the yeast strains. Wine color of sample wines after storage were not significantly different at p<0.05 and when compared with a commercial mango wine. From the volatile analysis, esters and alcohols constituted majority of the compounds. Production of several esters, alcohols, acids and terpenes were affected by yeast strain used in fermentation. Results of sensory analysis showed that wines fermented by S. bayanus EC-1118 strain was more acceptable although sensory scores between the treatments and the reference wine showed significant differences in all the attributes evaluated, except for bitterness. The utilization of osmotic solution from dried mango process could produce similar properties with existing commercial mango wines although there is still need for further work on the improvement of some sensory attributes of the mango wines.

• 한국축산식품학회지
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• 제38권6호
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• pp.1144-1154
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• 2018

Both the calcium and collagen in bone powder are hard to be absorbed by the body. Although enzymatic hydrolysis by protease increased the bio-availability of bone powder, it was a meaningful try to further increase $Ca^{2+}$ release, oligopeptide formation and antioxidant activity of the sheep bone hydrolysate (SBH) by lactic acid bacteria (LAB) fermentation. Lactobacillus helveticus was selected as the starter for its highest protease-producing ability among 5 tested LAB strains. The content of liberated $Ca^{2+}$ was measured as the responsive value in the response surface methodology (RSM) for optimizing the fermenting parameters. When SBH (adjusted to pH 6.1) supplemented with 1.0% glucose was inoculated 3.0% L. helveticus and incubated for 29.4 h at $36^{\circ}C$, $Ca^{2+}$ content in the fermented SBH significantly increased (p<0.01), and so did the degree of hydrolysis and the obtaining rate of oligopeptide. The viable counts of L. helveticus reached to $1.1{\times}10^{10}CFU/mL$. Results of Pearson correlation analysis demonstrated that LAB viable counts, $Ca^{2+}$ levels, obtaining rates of oligopeptide and the yield of polypeptide were positively correlated with each other (p<0.01). The abilities of SBH to scavenge the free radicals of DPPH, OH and ABTS were also markedly enhanced after fermentation. In conclusion, L. helveticus fermentation can further boost the release of free $Ca^{2+}$ and oligopeptide, enhance the antioxidant ability of SBH. The L. helveticus fermented SBH can be developed as a novel functional dietary supplement product.

• 미생물학회지
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• 제54권4호
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• pp.436-441
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• 2018

인삼은 우수한 약리 활성 작용을 보이는 전통적인 약초이다. 본 연구에는 프로바이오틱스 Lactobacillus helveticus KII13과 Pediococcus pentosaceus KID7 균주를 진세노사이드(ginsenoside) 함량을 증가시키기 위해 조 인삼 추출물을 발효시켜 진세노사이드를 형질전환 시키는데 사용되었다. 발효삼 추출물의 TLC(Thin-layer chromatography) 분석 결과, 5일간의 발효 후 주요 사포닌인 진세노사이드 Rg3, Rh1 및 Rh2로 변환되는 것으로 나타났다. HPLC 분석을 수행하여 주요 및 미량 진 세노사이드를 정량화하였다. 3일째에는 Rg3가 나타나고, 5일째에는 Rh2 및 Rh1이 나타난다. L. helveticus KII13과 P. pentosaceus KID7의 공동 배양은 주요 진세노사이드(Rb1과 Rg1)를 미량 진세노사이드(Rg3, Rh2, Rh1)로 전환시키는 것을 학인하였다.

• 미생물학회지
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• 제54권4호
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• pp.379-383
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• 2018

맥주는 가장 대중적인 알코올 발효주이지만 퓨린(purine) 함량이 높아 고요산혈증 및 통풍 발생과 연관이 있다고 알려져 있다. 본 연구에서는 맥주 발효 온도를 달리함으로써 맥주의 퓨린 함량을 낮출 수 있는지 알아보았다. 맥주 제조의 주된 발효법인 상면 발효와 하면 발효에서 주로 사용되는 $20^{\circ}C$와 $10^{\circ}C$ 온도에서 맥주를 발효한 후, 각각에서 대표적 퓨린 화합물인 adenine, guanine 그리고 xanthine들의 함량을 high performance liquid chromatography 방법으로 측정하였다. 그 결과, $10^{\circ}C$ 발효 맥주가 $20^{\circ}C$ 발효 맥주에 비해 총 퓨린 함량이 낮았으며, 특히 adenine의 함량이 의미있게 낮아져 있음을 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제32권3호
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• pp.307-316
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• 2022

Yeasts play an important role in spontaneous fermentation of traditional alcoholic beverages. Our previous study revealed that a mixed-consortia of both Saccharomyces and non-Saccharomyces yeasts were responsible for fermentation of khadi, a popular, non-standardized traditional beverage with an immense potential for commercialization in Botswana. Functional characterization of isolated fermenting yeasts from mixed consortia is an indispensable step towards the selection of potential starter cultures for commercialization of khadi. In this study, we report the characterization of 13 khadi isolates for the presence of brewing-relevant phenotypes such as their fermentative capacity, ability to utilize a range of carbon sources and their ability to withstand brewing-associated stresses, as a principal step towards selection of starter cultures. Khadi isolates such as Saccharomyces cerevisiae, Saccharomycodes ludwigii and Candida ethanolica showed good brewing credentials but Lachancea fermentati emerged as the isolate with the best brewing attributes with a potential as a starter culture. However, we were then prompted to investigate the potential of L. fermentati to influence the fruity aromatic flavor, characteristic of khadi. The aroma components of 18 khadi samples were extracted using headspace solid phase micro-extraction (HS-SPME) and identified using a GC-MS. We detected esters as the majority of volatile compounds in khadi, typical of the aromatic signature of both khadi and L. fermentati associated fermentations. This work shows that L. fermentati has potential for commercial production of khadi.

• 융합정보논문지
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• 제11권5호
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• pp.223-231
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• 2021

유산균에 의한 감국 추출물(CIL)의 항산화능의 변화를 알아보기 위해 64%, 80% ethanol 로 추출한 농도별 CIL를 발효시켜 total phenolic contents (TPC), flavonoid, 2,2-diphenyl-1-picrylhydrazyl (DPPH), reducing power (RP), linoleic acid 자동산화 저해활성의 변화를 확인해 보았다. TPC의 경우 3109, 3237에서 증가하였으며, flavonoid에서는 모든 균주에서 감소를 나타냈다. DPPH 측정에서는 64% CIL 발효 후 3074, 3109에서 증가하였으며, 80% CIL 발효에서는 모든 균주가 증가를 나타냈다. RP측정에서는 64%, 80% CIL에서 모든 균주에서 증가를 보였으며, linoleic acid 자동산화 저해활성에서는 모든 균주에서 감소를 나타냈다. 특히 3109 항산화능을 평가하는 DPPH와 RP 측정에서 다른 균주에 비해 전반적으로 높게 측정이 되었다. 결과적으로 4종의 유산균 중에서 3109가 발효과정을 통해서 CIL의 항산화 효능을 효과적으로 증대하는 것을 확인할 수 있었다.

• 한국식생활문화학회지
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• 제37권6호
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• pp.555-563
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• 2022

The purpose of this study was to confirm the quality characteristics of distilled soju with different rice pretreatment processes. The non-steamed fermentation method is a technology that uses starch to produce saccharification and alcohol without going through the steaming of raw materials. It has advantages such as reduction of manpower and cost, prevention of nutrient loss, and minimization of waste water. In this study, rice used were non-steamed and pulverized 'Baromi2', nonsteamed and steamed 'Samgwang', and puffed rice. As the fermenting agent, koji, modified nuruk, N9 yeast, and purified enzyme were used, and lactic acid was added to prevent contamination during fermentation. The amount of water was 300% in total, and after the first watering, 5 days after fermentation, the second watering was carried out. As a result of the study, it was confirmed that the non-steamed fermentation method using 'Baromi' was superior to the existing fermentation method in terms of temperature during fermentation, final alcohol content, soluble solids, and pH. By expanding the stability of the production technology of non-steamed fermentation technology, product quality improvement can be expected.

• Journal of Animal Science and Technology
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• 제65권3호
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• pp.652-663
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• 2023

The rumen fluids contain a wide range of bacteria, protozoa, fungi, and viruses. The various ruminal microorganisms in the rumen provide nutrients by fermenting the forage they eat. During metabolic processes, microorganisms present in the rumen release diverse vesicles during the fermentation process. Therefore, in this study, we confirmed the function of rumen extracellular vesicles (EVs) and their interaction with the host. We confirmed the structure of the rumen EVs by transmission electron microscope (TEM) and the size of the particles using nanoparticle tracking analysis (NTA). Rumen EVs range in size from 100 nm to 400 nm and are composed of microvesicles, microparticles, and ectosomes. Using the Caenorhabditis elegans smart animal model, we verified the interaction between the host and rumen EVs. Exposure of C. elegans to rumen EVs did not significantly enhance longevity, whereas exposure to the pathogenic bacteria Escherichia coli O157:H7 and Staphylococcus aureus significantly increased lifespan. Furthermore, transcriptome analysis showed gene expression alterations in C. elegans exposed to rumen EVs, with significant changes in the metabolic pathway, fatty acid degradation, and biosynthesis of cofactors. Our study describes the effect of rumen EV interactions with the host and provides novel insights for discovering biotherapeutic agents in the animal industry.

• Journal of Dairy Science and Biotechnology
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• 제41권3호
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• pp.113-125
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• 2023

In this study, we explored the synergistic effects of whey protein concentrate (WPC) and soybean protein components after fermentation with lactic acid bacteria isolated from kimchi, and identified several peptides with desirable physiological functions, proteolysis, and immune effects. Antioxidant activity was determined using 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid, 1,1-diphenyl-2-picrylhydrazyl, ferric-reducing antioxidant power, and hydroxyl radical scavenging assays, followed by cross-validation of the four antioxidant activities. These assays revealed that samples with a 8:2 and 9:1 whey to soy ratio possessed higher antioxidant activity than the control samples. Antibacterial potency testing revealed high antibacterial activity in the 9:1 and 8:2 samples. Cytotoxicity testing of samples using 3-(4, 5-dimethyl thiazol-2-yl)-2, 5-diphenyl tetrazolium bromide revealed that only the 10:0, 1:9, and 0:10 samples had <80% viable cells, indicating no significant cytotoxicity. Nitric oxide (NO) assays revealed that NO expression was reduced in 8:2, 5:5, and 0:10 protein ratio fermentations, indicating low inflammatory reaction stimulatory potential. Cytokine expression was confirmed using an enzyme-linked immunosorbent assay kit. The 8:2 sample had the lowest inflammatory cytokine (interleukin [IL]-1α, IL-6, and tumor necrosis factor-α) levels compared with the lipopolysaccharide-treated group. Amino acid profiling of the 8:2 sample identified 17 amino acids. These results suggest that inoculating and fermenting Lactobacillus plantarum DK203 and Lactobacillus paracasei DK209 with an 8:2 mixture of WPC and soybean protein releases bioactive peptides with excellent anti-inflammatory and antioxidant properties, making them suitable for functional food development.