본 연구는 이형발효 유산균을 첨가한 이탈리안 라이그라스 및 총체보리 사일리지의 저장 기간 동안의 변화에 따른 반추위 발효 효과를 규명하고자 수행하였다. 사일리지의 접종 균주는 이형발효 유산균으로 Lactobacillus casei KACC 12413 및 Lactobacillus reuteri KCTC 3594 및 Lactobacillus casei + Lactobacillus reuteri로 하였다. In vitro 실험의 pH 변화는 LCR 처리구가 높은 경향이었으며, 작물 간의 차이는 WCB사일리지 보다 IRG 사일리지의 pH가 높았다. 총 가스 생산량은 대조구에 비해 유산균 첨가구가 낮았고, WCB 보다 IRG 사일리지가 높은 수준이었다. 암모니아태 질소 농도는 유산균 첨가구 보다 대조구가 높은 경향이었고, 30일 보다 60일 사일리지가 낮았다. 총 휘발성지방산 생성량은 30일 및 60일 WCB 사일리지의 LC 처리구가 높았다. In situ 실험에서 건물 소화율은 48시간 발효 했을 때 LCR 처리구가 높았고 대조구가 가장 낮았다. 작물 간에 차이는 WCB에 비해 IRG가 8∼10% 더 높았다. NDF 소화율은 LC 처리구 및 LCR 처리구가 높은 경향이었고(p<0.05), ADF 소화율은 LC 처리구 및 LCR처리구가 높았다. 본 연구의 결과로 미루어 보아 propionate를 생성하는 이형 발효 유산균이 접종된 사일리지는 반추위 내 발효조건을 개선하고 가축의 사일리지 소화율을 증진 시킬 것으로 보이며, 가축의 생산성 및 사료가치가 향상 될 것으로 여겨진다.

Soymilk has been substituted for milk for people who are suffering from lactoseintolerance. In this study γ-aminobutyric acid (GABA) producing lactic acid bacterium, Lactobacillus plantarum LP2, was applied to ferment soymilk for improving its functionality. GABA production was proved in MRS broth supplemented 3% monosodium glutamate (MSG) and soymilk including 10% (w/v) soymilk powder and 5%(w/v) fructooligosaccharide where L. plantarum LP2 was applied. In addition to the soymilk, isolated soy protein (ISP), which was enzyme-treated, was added to it for improving the content of free amino acids including glutamic acid. L. plantarum LP2 was well grown and produced GABA in the soymilk medium.

The purpose of this study was to investigate the quality and antioxidant properties of three fermented sweet potato cultivars (Shinyulmi, Hogammi, and Shinjami) using lactic acid bacteria. During the fermentation, the pH was lowered and the titratable acidity increased. The viable cell counts of lactic acid bacteria increased 8.44-9.62 log CFU/g. Organic acid content (especially lactic acid) of sweet potatoes increased by fermentation. Also, γ-Aminobutyric acid increased more than 8.6 times by fermentation in all samples. The total polyphenol and flavonoid contents of sweet potato, showed insignificant changes in all samples by fermentation. ABTS radical scavenging activity of all samples slightly decreased by fermentation, but not significantly. DPPH radical scavenging activity decreased slightly by fermentation except Shinyulmi. However, when compared with the varieties, Shinjami showed the highest activity. The reducing power of Shinjami decreased slightly by fermentation, but activity was the highest among all samples. Based on these results, most of the chemical properties and functionality of fermented sweet potato are retained after fermentation, although some antioxidant activity decreases. We suggest that three fermented sweet potato cultivars (Shinyulmi, Hogammi, and Shinjami) using lactic acid bacteria can be used in various applications because of their effective functional properties.

The purpose of this study was to analyze the effectiveness of different storage periods of lactic acid bacteria (LAB)-fermented low moisture fresh rice straw silage. The low moisture fresh rice straw sample was inculcated with LAB and stored for different storage periods such as 45, 90, and 365 days, respectively. The low moisture fresh rice straw (LMFRS) silage inoculated with LAB exhibited reduction in pH throughout the fermentation as compared with the control (P<0.05). The lactic acid content was increased at the late fermentation period (90 and 365 days, respectively) in LAB inoculated LMFRS silage as compared with the control (P<0.05). In contrast, the acetic acid and butyric acid concentrations were slightly reduced in the LAB inoculated LMFRS silage sample at 90 and 365 days fermentation, respectively. Meanwhile, the non-inoculated LMFRS silage showed higher amounts of acetic acid and butyric acid at an extended fermentation with low bacterial population as compared with the LAB inoculated LMFRS silage. However, lactic acid concentration was slightly high in the non-inoculated LMFRS silage at early 45 days fermentation. Additionally, the nutrient profile such as crude protein (CP), acid detergent fibre (ADF), neutral detergent fibre (NDF), and total digestibility nutrients (TDN) were not significantly different in control and LAB inculcated samples during all fermentation. Though, the microbial population was greater in the LAB inoculated LMFRS silage as compared with the control. However, the massive population was noted in the LAB inoculated LMFRS silage during all fermentation. It indicates that the inoculated LAB is the main reason for increasing fermentation quality in the sample through pH reduction by organic acids production. Overall results suggest that the LAB inoculums are the effective strain that could be a suitable for LMFRS silage fermentation at prolonged days.

Fermented total mixed ration (TMR) is a novel feed for ruminants in South Korea. The purpose of this study was to evaluate the effects of lactic acid bacteria (LAB) on the quality of TMR and in vitro ruminal fermentation. Strains of three LAB spp. (Lactobacillus plantarum, L. brevis, L. mucosae) were used in fermentation of TMR. Inoculations with the three LAB spp. lowered pH and increased concentrations of lactic acid, acetic acid, and total organic acid compared to non-LAB inoculated control (only addition of an equivalent amount of water) (p<0.05). Bacterial composition indicated that aerobic bacteria and LAB were higher. However, E. coli were lower in the fermented TMR than those in the control treatment (p<0.05). Among the treatments, L. brevis treatment had the highest concentration of total organic acid without fungus detection. Gas production, pH, and ammonia-nitrogen during ruminal in vitro incubation did not differ throughout incubation. However, ruminal total VFA concentration was higher (p<0.05) in the LAB spp. treatments than the control treatment at 48 hours. Overall, the use of L. brevis as an inoculant for fermentation of high moisture. TMR could inhibit fungi growth and promote lactic fermentation, and enhance digestion in the rumen.

The effects of lactic acid bacteria (LAB) mixtures on low moisture Italian ryegrass (IRG) silage fermentation was evaluated in field conditions. The experiment was categorized into two groups: Un-inoculated (Control) and Inoculated with LAB mixture for four storage periods (45, 90, 180, and 365 days, respectively). Silage inoculated with the LAB mixture had the lowest pH with highest lactic acid production than the control from beginning at 45-365 days at all moistures. Higher LAB counts were observed in inoculated silages than the control silages at whole experimental periods. It is a key reason for the rapid acidification and higher lactic acid production in silages during the storage periods. Overall results suggest that an adding of LAB mixture had positive effects on the increasing aerobic stability of silage and preserved its quality for an extended duration.

콩 가공 부산물인 콩 배아 이소플라본의 생체내 활성을 증가시키기 위하여 LA, LB, LP 등 3가지 유산균을 단독 또는 혼합하여 비배당체화 전환 효율을 증가시키고자 균주의 종류와 접종량, 발효시간에 따른 이소플라본 함량을 분석하였다. 그 결과 균주를 이용한 모든 발효에서 균주를 사용하지 않은 대조군에 비하여 높은 이소플라본 비배당체 전환을 보였고, 발효시간에 따른 비배당체 전환율은 24시간에서 급격히 증가하였고 이후에는 큰 변화는 보이지 않았다. 비배당체화 발효의 최적 균주는 LP균, 접종량은 5%, 발효시간은 24시간 이었다. 대조군의 이소플라본 배당체의 구성은 글리시틴>다이드진>제니스틴 순으로 가장 높은 함량을 나타내었고, 유산균을 접종하여 발효시켰을 때 배당체들은 감소하였고, 비배당체 함량이 증가하였으며, 다이드제인>글리시테인>제니스테인 순으로 45% 이상의 비배당체 전환율을 나타내었다. 특히, 대조군과 비교하여 유산균으로 발효시켰을 때 다이드진의 함량이 가장 크게 감소하였고, 다이드제인 함량이 가장 크게 증가하였다. 소야사포닌의 경우 발효에 의하여 Ab가 급격하게 감소하였고 Ba와 Bb가 증가하였다. 발효액은 pH 3에서 pH 6으로 증가함에 따라 이소플라본 비배당체 함량이 증가하였으며 특히, 다이드제인 함량이 많이 증가하였고, 소야사포닌 함량은 Ab 함량이 급격하게 감소하였고, Ba와 Bb 함량도 소량감소하는 등 발효액의 pH가 발효에 의한 이소플라본과 소야사포닌 함량 변화에 많은 영향을 미치는 중요한 요인중의 하나임을 알 수 있었고, LP균을 이용한 발효로 가공부산물인 콩 배아의 생리활성 증가 및 기능성소재화를 꾀할 수 있을 것 으로 생각된다.

Nowadays micro-dust is a serious problem in Korea. In particular micro-dust contains heavy metals such as Pb (lead) and Cd (cadmium) which negatively effect on human health. In this study, we intended to isolate lactic acid bacteria which can scavenge the heavy metals. Firstly we isolated two lactic acid bacteria which were resistant to Ag, Cu, and Zn (30-100 mM AgNO3, CuSO4, ZnSO4 in MRS broth). The two lactic acid bacteria CJNU 1877 and JG 15 were identified Lactobacillus paracasei and Enterococcus faecium, respectively. Subsequently the strains were inoculated in MRS broth and agar plate where 100 ppm of Pb(NO3)2 and CdSO4 were added, respectively. They did grow in the conditions and we found aggregations from 24 h cultures, indicating the strains can absorb the heavy metals, which was further proved by scanning electron microscopy (SEM) and Inductively Coupled Plasma-Optical Emission Spectrometer. Therefore the isolated lactic acid bacteria can be used as a probiotics harboring heavy metal scavenging activity.

Ginseng, the root of the Panax ginseng, has been widely used as a traditional herbal medicine in Korea, China, and Japan for thousands of years. Now ginseng has become popular as functional health food and natural medicine and it is one of the bestselling natural products in the world. Gut microbiota has been found to play an important role in the metabolism and pharmacological action of orally administered ginseng. Recent animal and clinical studies have shown that compound K (20-O -beta-D-glucopyranosyl-20(S)-protopanaxadiol, CK) is the major ginsenoside metabolite deriving from gut microbiota-induced biotransformation and is more efficiently absorbed into the systemic circulation than its parent ginsenosides. Since ginsenoside metabolism varies between individuals depending on the population of gut microbiota, much attention paid to the transformation of major ginsenosides into more pharmacologically active ginsenosides using diverse methods including heating, acid hydrolysis, microbial conversion, and enzymatic treatment. Recently, in food and drug industry and academia, the development of fermented ginseng products using probiotic bacteria is being intensively studied due to the potential health benefits of ginsenoside metabolites and probiotics. This review summarizes recent studies on the metabolism of ginsenoside by gut microbiota and biotransformation of ginsenoside using lactic acid bacteria and their enzymes.

본 연구는 2017년 국내에서 유통되는 유산균을 함유한 건강기능식품과 가공식품 120건에 대하여 프로바이오틱스 함량, pH와 산도를 분석하였다. 또한, 건강기능식품 중 프로바이오틱스 5개 제품에 대한 보존방법에 따른 변화를 조사하였다. 프로바이오틱스 제품 85건 중 2건이 표시량 이하였고, 가공식품 35건은 모두 적합이었다. 프로바이오틱스 제품의 프로바이오틱스수, pH, 산도 평균은 각각 1.2 × 1010 CFU/g (표시량: 3.4 × 109 CFU/g), 5.35, 1.29%이었으며, 가공식품 중 유산균 함유량 표시 식품 17건의 유산균수 평균은 5.8 × 108 CFU/g이었다. 프로바이오틱스 5제품의 보존온도(−20℃, 4℃, 20℃, 40℃)와 보존기간(1, 3, 6개월) 경과에 따른 프로바이오틱스 함량 변화를 관찰한 결과, 보존기간 1개월에서 6개월 후 프로바이오틱스수 감소율은 평균 59%이었고, 4℃에서 가장 낮은 감소율과 40℃에서 가장 높은 감소율을 나타내었다. 또한, 5개 제품 중 3제품에서 보존기간 1개월에서 3개월 경과 후 40℃에서 70%이상 급격한 균수 감소를 관찰할 수 있었다. 따라서 프로바이오틱스 제품의 보존온도와 보관기간에 따른 변화를 고려할 때 프로바이오틱스 제품은 냉장보관을 권장하며 구입 후 되도록 단기간에 섭취하는 것이 바람직한 것으로 판단된다.

Edible biopolymer films were developed from the exopolysaccharides (EPS) extracted from Weissella confusa 113-2. The optimum composition for film formation was determined using the response surface analysis with the explanatory variables of the EPS (0.5-5.5%) and glycerol (0.5-5.5%) concentrations and the response variable of film elastic modulus (EM). The mass ratio of distilled water to solids was set constant (14:1). Tensile strength (TS), percentage elongation at break (%E), EM, water vapor permeability (WVP) of EPS films were evaluated. The glass transition temperatures of the films were also determined by a dynamic mechanical analysis. The optimum mass ratio of EPS to glycerol was 0.754:0.375. The WVP, TS, %E, and EM of the film under the optimal composition were 3.53±0.21 g·mm/kPa·h·m2, 7.03±0.49 MPa, 84.82±12.31%, and 62.03±6.93 MPa, respectively. The glass transition temperature varied from 54 to 83 °C. The EPS film has the potential to be applied to food products as an edible film with physical and barrier properties comparable to other biopolymer edible films.

This study was conducted to investigate the effect of addition of lactic acid bacteria inoculants on quality of rye silage harvested at early heading stage. The nutritive values in lactic acid bacteria (LAB) inoculated group showed similar results to control. The pH of rye silage in LAB inoculation significantly decreased as compared to control (P<0.05). In addition, the content of lactic acid in LAB inoculation significantly increased (P<0.05), but the content of acetic acid in LAB treatments decreased. In addition, lactic acid bacterial counts in LAB inoculation significantly increased as compared to control (P<0.05). Therefore, we suggest that rye silage could be improved by LAB inoculation.

β-glucosidase is an enzyme that hydrolyzes glycosidic bonds to generate terminal non-reducing residues in β-D-glucosides and oligosaccharides. These enzymes are used to degrade the plant cell walls of plant biomass. The 170 lactic acid bacteria isolated from beachu kimchi were examined for their β-glucosidase activity(E.C. 3.2.1.21.). Among the tested lactic acid bacteria, 48 strains utilized cellobiose as a carbon source. The highest β-glucosidase activity was 0.0537±0.0021(U/mg protein) in MSE129. MSE129 was identified to be Weissella koreenisis using 16S rRNA gene sequence analysis.