• 제목/요약/키워드: D-(-)-lactic acid

검색결과 505건 처리시간 0.025초

Probiotic bifidobacteria의 건강 증진 작용과 산업적 이용 (Health Benefits of Probiotic Bifidobacteria and Their Industrial Application)

  • 임광세
    • Journal of Dairy Science and Biotechnology
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    • 제21권2호
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    • pp.125-137
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    • 2003
  • Bifidobacteria are normal inhabitants of the human gastrointestinal tract throughout lift, starting just days after birth, and are one of several predominant species of the colonic microflora, along with Peptostreptococcus, Eubacteria, Clostridia, and Bacteroides. Bifidobacteria differ from lactic acid bacteria in that they produce not only lactic acid but also acetic acid as major fermentation products. The classification of bifidobacteria has changed numerous times since they were discovered in 1899 in the feces of breast-fed infants. Since 1994, three additional species have been included in the list (B. lactis, B. inopinatum, and B. denticolens), with a current total of 32 species. A variety of probiotic effects of bifidobacteria are currently being investigated. Research reports suggests several potential probiotic advantages, in particular antimicrobial effects, immune-modulation reduction of the cancer risk, and modulation of gastrointestinal flora. As technological challenges related to viability and enumeration are being overcome, milks fermented with these anaerobic microorganisms(alone or in combination with lactic acid bacteria) are more able to provide consistently satisfying with large numbers of viable microorganisms. Over 70 products containing bifidobacteria are currently offered around the world, including fermented milks, cheese, buttermilk frozen desserts, candy, and pharmaceutical preparations.

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Biotransformation of major ginsenosides in ginsenoside model culture by lactic acid bacteria

  • Park, Seong-Eun;Na, Chang-Su;Yoo, Seon-A;Seo, Seung-Ho;Son, Hong-Seok
    • Journal of Ginseng Research
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    • 제41권1호
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    • pp.36-42
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    • 2017
  • Background: Some differences have been reported in the biotransformation of ginsenosides, probably due to the types of materials used such as ginseng, enzymes, and microorganisms. Moreover, most microorganisms used for transforming ginsenosides do not meet food-grade standards. We investigated the statistical conversion rate of major ginsenosides in ginsenosides model culture during fermentation by lactic acid bacteria (LAB) to estimate possible pathways. Methods: Ginsenosides standard mix was used as a model culture to facilitate clear identification of the metabolic changes. Changes in eight ginsenosides (Rb1, Rb2, Rc, Rd, Re, Rf, Rg1, and Rg2) during fermentation with six strains of LAB were investigated. Results: In most cases, the residual ginsenoside level decreased by 5.9-36.8% compared with the initial ginsenoside level. Ginsenosides Rb1, Rb2, Rc, and Re continuously decreased during fermentation. By contrast, Rd was maintained or slightly increased after 1 d of fermentation. Rg1 and Rg2 reached their lowest values after 1-2 d of fermentation, and then began to increase gradually. The conversion of Rd, Rg1, and Rg2 into smaller deglycosylated forms was more rapid than that of Rd from Rb1, Rb2, and Rc, as well as that of Rg1 and Rg2 from Re during the first 2 d of fermentation with LAB. Conclusion: Ginsenosides Rb1, Rb2, Rc, and Re continuously decreased, whereas ginsenosides Rd, Rg1, and Rg2 increased after 1-2 d of fermentation. This study may provide new insights into the metabolism of ginsenosides and can clarify the metabolic changes in ginsenosides biotransformed by LAB.

Enhancement of Thermomechanical Properties of Poly(D, L-lactic-co-glycolic acid) and Graphene Oxide Composite Films for Scaffolds

  • Yoon, Ok-Ja;Sohn, Il-Yung;Kim, Duck-Jin;Lee, Nae-Eung
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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    • pp.548-548
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    • 2012
  • Thermomechanical and surface chemical properties of composite films of poly(D, L-lactic-co-glycolic acid) (PLGA) were significantly improved by the addition of graphene oxide (GO) nanosheets as nanoscale fillers to the PLGA polymer matrix. Enhanced thermomechanical properties of the PLGA/GO (2 wt.%) composite film, including an increase in the crystallization temperature and reduction in the weight loss, were observed. The tensile modulus of a composite film with increased GO fraction was presumably enhanced due to strong chemical bonding between the GO nanosheets and PLGA matrix. Enhanced hydrophilicity of the composite film due to embedded GO nanosheets also improved the biocompatibility of the composite film. Improved thermomechanical properties and biocompatibility of the PLGA composite films embedded with GO nanosheets may be applicable to biomedical applications such as scaffolds.

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A Study on the Prevention of Salmonella Infection by Using the Aggregation Characteristics of Lactic Acid Bacteria

  • Kim, Min-Soo;Yoon, Yeo-Sang;Seo, Jae-Gu;Lee, Hyun-Gi;Chung, Myung-Jun;Yum, Do-Young
    • Toxicological Research
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    • 제29권2호
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    • pp.129-135
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    • 2013
  • Salmonella is one of the major pathogenic bacteria that cause food poisoning. This study investigated whether heat-killed as well as live Lactobacillus protects host animal against Salmonella infection. Live and heat-killed Lactobacillusacidophilus was administered orally to Sprague-Dawley rats for 2 weeks before the rats were inoculated with Salmonella. Rise in body temperature was moderate in the group that was treated with heat-killed bacteria as compared to the Salmonella control group. The mean amount of feed intake and water consumption of each rat in the heat-killed bacteria group were nearly normal. The number of fecal Salmonellae was comparable between the live and the heat-killed L. acidophilus groups. This finding shows that L. acidophilus facilitates the excretion of Salmonella. Moreover, the levels of pro inflammatory cytokines, including tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 beta, in the heat-killed L. acidophilus group were significantly lower when compared to the levels in the Salmonella control group. These results indicate that nonviable lactic acid bacteria also could play an important role in preventing infections by enteric pathogens such as Salmonella.

알코올성 지방간을 유발시킨 마우스에서 유산균 발효 마늘추출물의 간 보호 효과 (Hepatoprotective Effects of Lactic Acid-Fermented Garlic Extracts on Fatty Liver-Induced Mouse by Alcohol)

  • 최지휘;김민석;유희종;김기호;이희섭;조홍연;이승현
    • 한국식품영양과학회지
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    • 제43권11호
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    • pp.1642-1647
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    • 2014
  • 본 연구는 Lactobacillus plantarum으로 발효시킨 유산균 발효 마늘추출물의 간 손상 보호 효과를 알코올성 지방간을 유발시킨 C57BL/6J 마우스를 사용하여 확인하고자 하였다. 유산균 발효 마늘추출물은 일반식이군에 비해 지방간 유도와 함께 증가한 간 무게를 용량 의존적으로 감소시켰다. 유산균 발효 마늘추출물 200 mg/kg 투여군에서 대표적 간 손상 관련 혈청효소인 ALT, AST 및 ALP의 활성이 낮았으며, 간 손상의 다른 중요한 지표들인 TBIL, DBIL 값도 현저히 낮았다. 또한 유산균 발효 마늘추출물은 간의 조직학적 관찰에서도 알코올로 유도된 간 지방의 축적을 농도 의존적으로 개선하였다. 간 조직 내 GSH 함량을 측정한 결과, 알코올에 의해 감소된 GSH가 유산균 발효 마늘추출물 투여에 의해 점차 일반식이군 수준으로 회복됨을 알 수 있었다. 이상의 연구 결과는 유산균 발효에 의해 마늘의 냄새와 맛을 개선시킨 유산균 발효 마늘추출물이 알코올성 지방간의 예방 및 개선을 위한 기능성식품용 상업적 소재로서 높은 실용화 가능성을 시사한다.

두유(豆乳)를 이용(利用)한 요구르트 제조(製造)에 대하여 (Studies on Production Yoghurt from Soy Flour)

  • 유성식;이상갑;김진호;박우철
    • Current Research on Agriculture and Life Sciences
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    • 제7권
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    • pp.23-32
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    • 1989
  • 대두(大豆)를 이용(利用)한 요구르트 및 유산균(乳酸菌) 음료(飮料)의 제조(製造)를 위(爲)하여 두유(豆乳) 요구르트에 대한 유산균(乳酸菌) 생육(生育)과 산생성(酸生成) 및 여러가지 첨가물(添加物)에 대한 영향(影響)을 조사(調査)하였다. 시비조건(施肥條件)에 차이(差異)를 두어 재배(栽培)한 대두(大豆)를 이용(利用)한 두유(豆乳)에서의 유산균(乳酸菌) 생육(生育) 및 산생성(酸生成)은 큰 차이(差異)가 없었으나 개발복비(開發複肥)를 사용(使用)한 Soybean D가 다소(多少) 양호(良好)한 것으로 나타났으며, 두유(豆乳), 탈지두유 및 분리대두단백(分離大豆蛋白)에서의 산생성(酸生成)은 두유(豆乳)가 탈지두유보다 양호(良好)했으며 분리(分離) 대두단백(大豆蛋白)으로 조제(調製)한 두유(豆乳)에서는 현저(顯著)히 낮았다. 두유(豆乳) 요구르트의 제조(製造)에 사용(使用)한 균주별(菌株別) 산생성능력(酸生成能力)은 L. bulagricus와 L. acidophilus가 우수(優秀)하였다. 당(糖)과 각종(各種) 발육촉진물질(發育促進物質)의 첨가(添加)에 의해 균증식(菌增殖) 및 산생성(酸生成)이 촉진(促進)되었으며 특(特)히 Glucose와 Yeast Extract의 첨가(添加)는 현저(顯著)한 효과(效果)를 나타내었다.

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Effects of Maturity Stages on the Nutritive Composition and Silage Quality of Whole Crop Wheat

  • Xie, Z.L.;Zhang, T.F.;Chen, X.Z.;Li, G.D.;Zhang, J.G.
    • Asian-Australasian Journal of Animal Sciences
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    • 제25권10호
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    • pp.1374-1380
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    • 2012
  • The changes in yields and nutritive composition of whole crop wheat (Triticum aestivum L.) during maturation and effects of maturity stage and lactic acid bacteria (LAB) inoculants on the fermentation quality and aerobic stability were investigated under laboratory conditions. Whole crop wheat harvested at three maturation stages: flowering stage, milk stage and dough stage. Two strains of LAB (Lactobacillus plantarum: LAB1, Lactobacillus parafarraqinis: LAB2) were inoculated for wheat ensiling at $1.0{\times}10^5$ colony forming units per gram of fresh forage. The results indicated that wheat had higher dry matter yields at the milk and dough stages. The highest water-soluble carbohydrates content, crude protein yields and relative feed value of wheat were obtained at the milk stage, while contents of crude fiber, neutral detergent fiber and acid detergent fiber were the lowest, compared to the flowering and dough stages. Lactic acid contents of wheat silage significantly decreased with maturity. Inoculating homofermentative LAB1 markedly reduced pH values and ammonia-nitrogen ($NH_3$-N) content (p<0.05) of silages at three maturity stages compared with their corresponding controls. Inoculating heterofermentative LAB2 did not significantly influence pH values, whereas it notably lowered lactic acid and $NH_3$-N content (p<0.05) and effectively improved the aerobic stability of silages. In conclusion, considering both yields and nutritive value, whole crop wheat as forage should be harvested at the milk stage. Inoculating LAB1 improved the fermentation quality, while inoculating LAB2 enhanced the aerobic stability of wheat silages at different maturity stages.

Characterization of Lactobacillus acidophilus Isolated from Piglets and Chicken

  • Ahn, Y.T.;Lim, K.L.;Ryu, J.C.;Kang, D.K.;Ham, J.S.;Jang, Y.H.;Kim, H.U.
    • Asian-Australasian Journal of Animal Sciences
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    • 제15권12호
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    • pp.1790-1797
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    • 2002
  • Lactic acid bacteria were isolated from piglets and chicken and characterized. Lactic acid bacteria showing resistance to low pH and bile, adhesion to intestinal epithelium cells, and the inhibition of Escherichia coli and Salmonella spp. were identified as Lactobacillus acidophilus. L. acidophilus PF01 survived for 2 h in MRS broth adjusted to pH 2. L. acidophilus CF07 was less resistant than L. acidophilus PF01 to pH 2, but survived at pH 2.5 for 2 h. Both of isolates were able to grow in MRS broth containing 0.3% (w/v) bile, with L. acidophilus CF07 being more tolerant to bile than L. acidophilus PF01. L. acidophilus PF01 and CF07 adhered specifically to the duodenal and jejunal epithelium cells of piglet, and the cecal and duodenal epithelium cells of chicken, respectively. Both of isolates did not adhere to the epithelium cells of the various animal intestines from which they were isolated. When L. acidophilus was cultured with E. coli and Salmonella spp. in MRS broth, MRS broth containing 2% skim milk powder or modified tryptic soy broth at $37^{\circ}C$, L. acidophilus PF01 and CF07 inhibited the growths of E. coli K88 and K99, and S. enteritidis and S. typhimurium, respectively. Both of isolates were found to possess the essential characteristics of probiotic lactic acid bacteria for piglet and chicken.

Fermentation characteristics and microbial community composition of wet brewer's grains and corn stover mixed silage prepared with cellulase and lactic acid bacteria supplementation

  • Guoqiang Zhao;Hao Wu;Yangyuan Li;Li Li;Jiajun He;Xinjian Yang;Xiangxue Xie
    • Animal Bioscience
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    • 제37권1호
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    • pp.84-94
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    • 2024
  • Objective: The objective of this study was to investigate how cellulase or/and lactic acid bacteria (LAB) affected the fermentation characteristic and microbial community in wet brewer's grains (WBG) and corn stover (CS) mixed silage. Methods: The WBG was mixed thoroughly with the CS at 7:3 (w/w). Four treatment groups were studied: i) CON, no additives; ii) CEL, added cellulase (120 U/g fresh matter [FM]), iii) LAB, added LAB (2×106 cfu/g FM), and iv) CLA, added cellulase (120 U/g FM) and LAB (2×106 cfu/g FM). Results: All additive-treated groups showed higher fermentation quality over the 30 d ensiling period. As these groups exhibited higher (p<0.05) LAB counts and lactic acid (LA) content, along with lower pH value and ammonia-nitrogen (NH3-N) content than the control. Specifically, cellulase-treated groups (CEL and CLA) showed lower (p<0.05) neutral detergent fiber and acid detergent fiber contents than other groups. All additives increased the abundance of beneficial bacteria (Firmicutes, Lactiplantibacillus, and Limosilactobacillus) while they decreased abundance of Proteobacteria and microbial diversity as well. Conclusion: The combined application of cellulase and LAB could effectively improve the fermentation quality and microbial community of the WBG and CS mixed silage.

두경부 환자의 3D Printing을 이용한 Silicon Bolus의 유용성 (Usefulness of Silicon Bolus Using 3D Printing of Head and Neck Patients)

  • 권경태;이용기;원영진
    • 한국방사선학회논문지
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    • 제13권7호
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    • pp.909-916
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    • 2019
  • 구강 및 두경부 암의 방사선치료 시 치료 범위에 피부를 포함하는 경우가 많으며 이때 볼루스의 사용이 빈번해진다. 특히 턱 부분의 요철로 인하여 환자의 적용 시 선량 불확실성을 제공한다. 본 연구에서는 3D Printing을 이용하여 Gel 볼루스와 Poly lactic acid(PLA), Silicon을 적용한 환자 맞춤형 볼루스를 제작하여 물성 특성을 확인하고, 제작된 볼루스와 치료계획의 불일치성을 확인하며, 실제 방사선 선량 전달시 발생하는 선량불확실성을 측정하였다. 그 결과 일반적인 요철 부위에는 PLA 재질의 볼루스가 안정적이며, 요철이 심하거나 환자의 체형이 자주 바뀔 수 있는 환자의 경우 Silicon 재질의 볼루스가 유용할 것으로 사료된다.