• 한국미생물·생명공학회지
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• 제10권3호
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• pp.211-215
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• 1982

Streptomyces griseorubiginosus var. soyoensis 에 의하여 두가지의 항진균성 항생물질이 생성되었는데 하나는 trans-cinnamamide 이었고 다른 하나는 UV, IR, NMR, mass spectrum 및 화학반응의 결과로 새로운 tetraene계 화합물임이 밝혀져 이 물질을 Tetraene KM-A라 하였다. 본 물질의 항균성을 조사한 결과 곰팡이 및 효모류에 대하여는 강한 항진균성을 나타내었으나 항세균성은 없었다. 배지에 sterol류를 첨가하였을때 Tetraene KM-A의 항균력이 없어지는 것으로 보아 stesoid와 결함함을 알수 있고 항균작용도 이와 관련이 있는 것으로 판단하였다. Tetraene KM-A의 mouse 및 rat에 대한 복강주사에 의한 $LD_{50}$ 은 각각 84.3과 90.4mg/kg이였으며 mouse에 대만 경구독성은 1503mg/kg이었다.

• Journal of Microbiology and Biotechnology
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• 제10권1호
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• pp.56-62
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• 2000

The hpa gene genetically linked to the ctxa2b gene was cloned into the pTED expression vector, and the constructed pTEDhpa/ctxa2b was transformed into Excherichia coli. The fusion protein, the adhesin fused to the cholera toxin subunit A2B (CTXA2B) subunit, was expressed to high levels as inclusion bodies in E. coli. The expressed protein was partially purified by washing the inclusion bodies with working solution containing 8M Urea and 0.1M DTT. Refolding of denatured fusion protein was carried out in the presence of glutathione redox buffer. The refolded fusion protein was purified by size exclusion chromatography. The expressed fusion protein was verified by SDS-PAGE, western blotting with antibodies to both antigenic components of adhesin and cholera toxin subunit B (CTXB), and its N-terminal amino acid sequence was analyzed. The orderly assembled fusion protein was confirmed by modified Gm1-ganglioside ELISA with Abs to adhesin. The results indicate that the purified fusion protein is an Adhesin/CTXA2B protein containing the H. pylori adhesin and $G_{m1}4-ganglioside binding activity of CTXB and the expressed fusion protein in E. coli could be easily purified by the refolding process, Its molecular weight was 168kDa as estimated by size exclusion chromatography. The Adhesin/CTXA2B protein may be used as a candidate antigen for oral immunization against H. pylori.

• Journal of Microbiology and Biotechnology
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• 제25권10호
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• pp.1687-1696
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• 2015

Supplementation with probiotics can protect against the development of food allergies by modulating the host immune response; however, the mechanisms are not fully understood. The objective of this study was to investigate the allergy-reducing effects of regulatory dendritic cells (regDCs) induced by Lactobacillus paracasei L9 (L9) in β-lactoglobulin (BLG)-sensitized mice. The L9 supplement suppressed the aberrant balance of Th1/Th2 responses to BLG in mice, via upregulation of the CD4+CD25+Foxp3+Treg cell responses. The amount of CD4+CD25+Foxp3+Treg cells in mesenteric lymph nodes increased by 51.85%. Furthermore, administration of L9 significantly induced the expression of CD103 and reduced the maturation status of DCs in mesenteric lymph nodes, Peyer's patches, and spleen. Bone marrow-derived dendritic cells (BM-DCs) were activated by L9 in vitro, with an approximate 1.31-fold and 19.57-fold increase in expression of CD103 in CD11c+DCs and the level of IL-10 production, respectively, while the expression of CD86 did not change significantly. These data demonstrate that L9 reduced the BLG allergic sensitization, likely through regDCs mediated active suppression.

• Journal of Microbiology and Biotechnology
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• 제25권6호
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• pp.863-871
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• 2015

Bifidobacterium longum subsp. longum BBMN68, isolated from centenarians in Guangxi, China, has been proved to be a promising probiotic strain for its health benefits. In this study, the biodistribution of this strain in the rat gut was first investigated using the quantitative realtime PCR assay and propidium monoazide. Strain-specific primers were originally designed based on the BBMN68 genome sequence. Healthy rats were orally inoculated with either a single dose of BBMN68 (10¹⁰ colony-forming units/kg), or with one dose per day for 7 days and bacterial concentrations were analyzed in detail from the intestinal contents and feces of four different gut locations, including stomach, small intestine, colon, and rectum. Results indicated that strain BBMN68 could overcome the rigors of passage through the upper gastrointestinal tract and transiently accumulate in the colon, even though survival in the stomach and small intestine was not high. A good level of BBMN8 could stay in vivo for 72 h following a 7-day oral administration, and a daily administration is suggested for a considerable and continuous population of BBMN68 to be maintained in the host intestine.

• Journal of Microbiology and Biotechnology
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• 제28권11호
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• pp.1800-1805
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• 2018

Inflammatory bowel disease, including Crohn's disease and ulcerative colitis (UC), is a chronically relapsing inflammatory disorder of the gastrointestinal tract. Intestinal epithelial cells (IECs) constitute barrier surfaces and play a critical role in maintaining gut health. Dysregulated immune responses and destruction of IECs disrupt intestinal balance. Dextran sodium sulfate (DSS) is the most widely used chemical for inducing colitis in animals, and its treatment induces colonic inflammation, acute diarrhea, and shortening of the intestine, with clinical and histological similarity to human UC. Current treatments for this inflammatory disorder have poor tolerability and insufficient therapeutic efficacy, and thus, alternative therapeutic approaches are required. Recently, dietary supplements with probiotics have emerged as promising interventions by alleviating disturbances in the indigenous microflora in UC. Thus, we hypothesized that the probiotic Bifidobacterium animalis subsp. lactis strain BB12 could protect against the development of colitis in a DSS-induced mouse model of UC. In the present study, oral administration of BB12 markedly ameliorated DSS-induced colitis, accompanied by reduced tumor necrosis factor-${\alpha}$-mediated IEC apoptosis. These findings indicate that the probiotic strain BB12 can alleviate DSS-induced colitis and suggest a novel mechanism of communication between probiotic microorganisms and intestinal epithelia, which increases intestinal cell survival by modulating pro-apoptotic cytokine expression.

• Journal of Microbiology and Biotechnology
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• 제24권12호
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• pp.1736-1743
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• 2014

In this study, we evaluated the effect of Lactobacillus plantarum HY7714 on skin hydration in human dermal fibroblasts and in hairless mice. In Hs68 cells, L. plantarum HY7714 not only increased the serine palmitoyltransferase (SPT) mRNA level, but also decreased the ceramidase mRNA level. In order to confirm the hydrating effects of L. plantarum HY7714 in vivo, we orally administered vehicle or L. plantarum HY7714 at a dose of $1{\times}10^9CFU/day$ to hairless mice for 8 weeks. In hairless mice, L. plantarum HY7714 decreased UVB-induced epidermal thickness. In addition, we found that L. plantarum HY7714 administration suppressed the increase in transepidermal water loss and decrease in skin hydration, which reflects barrier function fluctuations following UV irradiation. In particular, L. plantarum HY7714 administration increased the ceramide level compared with that in the UVB group. In the experiment on SPT and ceramidase mRNA expressions, L. plantarum HY7714 administration improved the reduction in SPT mRNA levels and suppressed the increase in ceramidase mRNA levels caused by UVB in the hairless mice skins. Collectively, these results suggest that L. plantarum HY7714 can be a potential candidate for preserving skin hydration levels against UV irradiation.

• 대한치과교정학회지
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• 제42권2호
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• pp.87-93
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• 2012

Objective: The purpose of this study was to investigate the antimicrobial effect of silverized elastomers on mutans streptococci in dental plaque. Methods: Forty patients undergoing orthodontic treatment were randomly placed into 1 of 2 groups. We examined the maxillary right and left central incisors and premolars, and the mandibular right and left canines of all participants. We ligated the right maxillary and left mandibular teeth of the participants in group 1 with silverized elastomers and ligated their contralateral teeth with conventional elastomers. We ligated the left maxillary teeth and right mandibular teeth of group 2 participants with silverized elastomers. Each participant visited the clinic 4 times at 3-week intervals. We applied the elastomers to the teeth on one side of each patient's mouth during their first visit. During the second visit, the elastomers were removed for microbiological analysis and replaced with steel ligatures. During the third visit, we used silverized elastomers to ligate the teeth contralateral to those treated on the first visit. The elastomers were removed during the fourth visit, and microbiological analyses were performed. We compared the quantity of bacteria on silverized and conventional elastomers at the 0.05 level of significance. Results: The percentage of mutans streptococci was not significantly different in cultures of dental plaque from the silverized and the conventional elastomers (p > 0.05). Conclusions: There was no significant difference between the antimicrobial effect of the silverized elastomers and that of the conventional elastomers.

• 대한소아치과학회지
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• 제29권4호
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• pp.625-631
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• 2002

임상에서 사용하고 있는 8종의 항우식 작용을 갖는 항균물질의 조합이 대표적 우식유발 세균인 Streptococcus mutans Ingbritt와 Streptococcus sobrinus 6715-7의 성장에 미치는 영향을 조사하고자 세균별로 28개 조합의 각 항균물질에서 최소 저해 농도와 분할 저해 농도 지수를 구하여 여러 기준에 따라 상승작용, 길항작용, 무관함, 부분적 상호작용 등을 각각 평가하였다. 미국 미생물 학회의 지침에 따라 분류하면 약 34%의 조합에서 상승작용이 관찰되었고 Berenbaum의 분류에 따르면 약 82%에서 상승작용을 갖는다고 해석할 수 있었다. 또한 Isenberg가 정의한 부분적 상승작용은 총 조합수의 절반에서 관찰되었다. 분류기준에 따라 다양한 결과를 얻을 수 있었으나 두 가지 항균물질의 조합이 우식유발 세균을 억제하는데 상승작용을 나타내는 경향이 존재함을 관찰할 수 있었고 따라서 우식유발세균을 억제하는데 있어서 항균물질의 단독 사용보다 세균의 생태와 대사의 여러 부분에 영향을 미치는 항균물질의 조합은 유용할 수 있다는 것을 알 수 있었다.

• Journal of Periodontal and Implant Science
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• 제29권4호
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• pp.953-964
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• 1999

본 연구는 세 종류의 Porphyromonas gingivalis(Pg) antigen의 IgG subclass associated recognition을 평가하기 위해 수행했었다. 총 35명의 조기발병형치주질환자중, Pg381에 대한 IgG2항체의 증가를 보이는 5명이 급속진 행형 치주질환자, IgG4의 증가를 보이는 6명의 환자(국소유년형 치주질환자 2명과 급속진행 형 치주질환자 4명), IgG2+4의 증가를 보이는 2명의 급속진행형 치주질환자 그리고 IgG1+2+4의 증가를 보이는 8명의 환자(국소 유년형 치주질환자 2명과 급속진행형 치주질환자 6명)으로 구성된 21명의 환자를 dot immunoblot analysis를 위해 선택했다. 실험에 사용된 정제된 항원은 Pg381에서 추출한 43-kd fimbrilin protein과 lipoplysaccharide(LPS), Pg A7A1-28(ATCC 53977)에서 추출한 capsularpolysaccharide(CPS)였다. Immunoblotting pattern은 IgG4 antibody가 fimbrial antigen에 강력히 반응함을 보여주었다. Fimbriae에 잘 반응하는 몇몇의 IgG4 antibody역시 antigen에 대해 양성반응을 보였다. 대조적으로 IgG2는 CPS antigen을 일차적으로 인식했다. 전부는 아니지만 대부분의 경우, single이나 group화된 IgG subclass는 모두 LPS antigen을 인식하지 못했다. 같은 group에서 염색강도의 개인적인 차이는 증명되었다. 이런 결과는 조기발 병형 치주질환에서 Pg의 fimbriae와 CPS가 immunodominant antigen이 될 수 있음을 제시한다. 더욱이 IgG subclass antibody가 이런 Pg의 immunoglobulin antigen을 선택적으로 인식함을 알았고, 이는 조기발병형치주질환의 병리에 immunodominant antigen과 함께 IgG의 기능적인 역할을 고려해야 함을 제시한다.

• Journal of Microbiology and Biotechnology
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• 제19권1호
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• pp.108-112
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• 2009

A simplified method for the purification of cholera toxin was developed. The 569B strain of Vibrio cholerae, a recognized hyper-producer of cholera toxin, was propagated in a bioreactor under conditions that promote the production of the toxin. The toxin was separated from the bacterial cells using 0.2-${\mu}m$ crossflow microfiltration, the clarified toxin was passed through the membrane into the permeate, and the bacterial cells were retained in the retentate. The 0.2-${\mu}m$ permeate was then concentrated 3-fold and diafiltered against 10 mM phosphate buffer, pH 7.6, using 30-kDa crossflow ultrafiltration. The concentrated toxin was loaded onto a cation exchange column, the toxin was bound to the column, and most of the impurities were passed unimpeded through the column. The toxin was eluted with a salt gradient of phosphate buffer, pH 7.0, containing 1.0 M NaCl. The peak containing the toxin was assayed for cholera toxin and protein and the purity was determined to be 92%. The toxin peak had a low endotoxin level of $3.1\;EU/{\mu}g$ of toxin. The purified toxin was used to prepare antiserum against whole toxin, which was used in a $G_{M1}$ ganglioside-binding ELISA to determine residual levels of toxin in an oral inactivated whole-cell cholera vaccine. The $G_{M1}$ ganglioside-binding ELISA was shown to be very sensitive and capable of detecting as little as 1 ng/ml of cholera toxin.