• 한국균학회지
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• 제29권1호
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• pp.67-71
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• 2001

민간약재로 사용되어지는 아카시재목 버섯(Fomitella fraxinea) 자실체의 에탄올 추출물로부터 ethyl acetate 추출, silica gel chromatography, preparative TLC 등의 방법으로 항산화 활성을 나타내는 steroid계 화합물, F-1을 분리 정제하였다. EI-Mass, FT-IR, $^1H$ 및 $^{13}C$ NMR 등 기기 분석에 의하여 F-1은 분자량이 412.65, 분자식이 $C_{28}H_{44}O_2$의 steroid 화합물, ergosta-7,22-diene-3-one-$16{\beta}-ol$임을 확인하였다. F-1의 지질과산화 저해활성은 $10^{\mu}g/ml$의 농도에서 86%의 지질과산화 저해활성을 나타내었으며, $IC_{50}$ 값은 $3.8{\mu}g/ml$이었다. 이 화합물은 항산화제인 ${\alpha}-tocoperol$과 유사한 항산화 활성을 나타내었다.

• 한국미생물·생명공학회지
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• 제27권1호
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• pp.8-14
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• 1999

This study was developed to evaluate the growth inhibition effects of cell wall components of Enterococcus faecalis 2B4-1 obtained from feces of neonates against tumor cell lines. Polysaccharide fraction (PS) shown sensitive growth inhibition effect in the cell wall components was isolated and characterized. In growth inhibition effects, residue fractin of whole cell was shown sensitive level of percent survival about 30% when administrated at ehe concentration of 100${\mu}$g/ml, and that was more effective than that of supernatant fraction against the tumor cell lines, SNU-1, 3LL, FARROW and HEC-1-B. Sensitive growth inhibition effects against SNU-1, FARROW and HEC-1-B were performed by whole cell (WC) fraction from Ent. faecalis 2B4-1. Cytoplasm fractin (CP) of WC was shown non-inhibition effect, however, the other part of WC, precipitate of disrupted cell (PD), was sensitive against the tumor cell line mentioned above. Followed by separation to peptidoglycan fraction (PG) and polysaccharide fraction (PS) were all sensitive which the latter was shown more sensitive percent survival than the former. Composed sugars of polysaccharide fraction were determined to D-glucose, L-rhamnose and D-glucosamine, and the rate fo composition was calculated to about 1:1:1 by the data of elemental analysis, IR, TLC and HPLC.

• 한국자원식물학회지
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• 제8권2호
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• pp.135-141
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• 1995

갯방풍(防風)의 품질(品質)은 홍색(紅色)의 착색과정(着色過程)에 따라 크게 좌우(左右)되기 때문에 보다 확실(確實)한 착색기술(着色技術)의 확립(確立)이 요망(要望)된다. 따라서 본 실험(實驗)은 갯방풍(防風)의 Anthocyanin 생성(生成)에 미치는 환경요인(環境要因)을 구명(究明)하고자 수행(遂行)하였던 바 얻어진 결과(結果)는 다음과 같다. 1. 온도처리(溫度處理)에 따른 갯방풍(防風)의 발아율(發芽率)은 20/$15^{\circ}C$ 에서 가장 높았고, 30/$25^{\circ}C$에서는 거의 발아(發芽)가 되지 않았다. 또한 지상부(地上部) 생체중(生體重)은 25/$20^{\circ}C$에서 가장 양호(良好)했다. Anthocyanin 생성(生成)은 15/$10^{\circ}C$의 온도(溫度)에서 가장 높았고, 30/$25^{\circ}C$의 고온(高溫)에서 억제(抑制) 되었다. 2. 각(各) 온도조건(溫度條件)에서 광처리구(光處理區) 간(間)의 지상부(地上部) 생체중(生體重)에는 큰차가 없었다. 또한 광(光)은 Anthocyanin 생성(生成)을 촉진(促進)하는 것으로 인정(認定)되었으며, 특히 광(光)의 그 촉진작용(促進作用)은 저온(低溫)에서 더욱 효과적(效果的)이었다. 3. 자외선처리(紫外線處理)에 따른 지상부생육(地上部生育)은 전반적(全般的)으로 큰차는 없었지만, 25/$20^{\circ}C$에서는 자외선(紫外線) 투과구(透過區)가 자외선(紫外線) 차단구(遮斷區)에 비해 양호(良好)한 경향(傾向)을 보였다. Anthocyanin생성(生成)은 자외선투과구(자외선투과구)가 자외선차단구(紫外線遮斷區) 보다 많았던 점으로 보아 Anthocyanin생성(生成)에 대한 자외선(紫外線)의 효과(效果)가 인정(認定)되었다.

• Journal of Microbiology and Biotechnology
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• 제18권6호
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• pp.1064-1069
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• 2008

Levan fructotransferase (LFTase) preferentially catalyzes the transfructosylation reaction in addition to levan hydrolysis, whereas other levan-degrading enzymes hydrolyze levan into a levan-oligosaccharide and fructose. Based on sequence comparisons and enzymatic properties, the fructosyl transfer activity of LFTase is proposed to have evolved from levanase. In order to probe the residues that are critical to the intramolecular fructosyl transfer reaction of the Microbacterium sp. AL-210 LFTase, an error-prone PCR mutagenesis process was carried out, and the mutants that led to a shift in activity from transfructosylation towards hydrolysis of levan were screened by the DNS method. After two rounds of mutagenesis, TLC and HPLC analyses of the reaction products by the selected mutants revealed two major products; one is a di-D-fructose-2,6':6,2'-dianhydride (DFAIV) and the other is a levanbiose. The newly detected levanbiose corresponds to the reaction product from LFTase lacking transferring activity. Two mutants (2-F8 and 2-G9) showed a high yield of levanbiose (38-40%) compared with the wild-type enzyme, and thus behaved as levanases. Sequence analysis of the individual mutants responsible for the enhanced hydrolytic activity indicated that Asn-85 was highly involved in the transfructosylation activity of LFTase.

• Applied Biological Chemistry
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• 제37권1호
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• pp.49-55
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• 1994

벼잎의 산성용액 추출물로부터 ion exchange chromatography chitin affinity chromatography chromatofocusing gel slicing 등의 방법으로 단백질 RCG-2를 순수분리하였다. 본 단백질은 chitin과 laminarin을 가수분해하므로 chitinase와 ${\beta}-1,3-glucanase$ 활성을 함께 보유하고 있는 것으로 나타났으며, 이외에도 M. lysodeiktikus cell wall을 가수분해하는 lysozyme 활성도 보유하는 것으로 판명되었다. 분자량이 29.77 kd인 본 효소의 chitinase 활성은 pH 4.0에서, ${\beta}-1,3-glucanase$ 활성은 pH 7.0에서 최대로 나타났고, 최적온도는 두 효소 활성 모두 $40^{\circ}C$ 이었다. chitin에 대한 $K_M$ 값은 7.86 mM, $V_{max}$는 $0.025\;{\mu}M/min$, laminarin $({\beta}-1,3-glucan)$에 대한 것은 각각 5.95 mM, $0.16{\mu}\;M/min.$ 이었으며, 정제된 효소는 chitin을 chitooligosaccharide로 분해하는 것으로 나타나서 endochitinase로 판명되었다.

• Applied Biological Chemistry
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• 제46권2호
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• pp.69-73
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• 2003

병원에서 분리한 azole계 항진균성 항생물질에 대한 내성을 가지고 있는 Candida albicans에 대해 강한 활성을 가지는 항진균성 물질을 Bacillus subtilis LAM 97-44의 배양액으로부터 분리 정제한 후 그 특성을 조사하였다. 원심분리한 배양상등액을 butanol 추출, Diaion HP-20과 Dowex-50 adsorption chromatography, silica gel flash chromatography와 HPLC로 정제하였고 TLC와 HPLC로 확인하여 그 물질을 LAM-44A라 명명하였다. LAM-44A는 pH와 열에 매우 안정하였으며 Candida sp., Cryptococcus sp. 등에 대해 강한 활성을 나타낸 반면에 독성은 매우 적었다. 분리한 물질은 273 m에서 최대흡광도를 가진 융점 $202^{\circ}C$의 무색분말이었으며 ninhydrin 반응결과 음성이었고 $^1H-NMR$, $^{12}C-NMR$, IR spectrum, 원소분석 등의 결과로 볼 때 분자량 282의 $C_{14}H_{34}O_5$의 화학식을 가진 물질로 동정되었다.

• Journal of Microbiology and Biotechnology
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• 제13권1호
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• pp.50-56
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• 2003

A freshwater bloom-forming cyanobacterium, Microcystis aeruginosa, and local soil isolate Scytonema sp. strain BT 23 were demonstrated to contain biotoxic secondary metabolites with pesticidal and mosquito larvicidal activities. A purified toxic constituent from M aeruginosa showed an absorption maximum at 230 nm and its toxicity symptoms, Rf value on TLC, and retention time observed ill an HPLC analysis were similar to those of the hepatotoxic heptapeptide microcystin-LR. The bioactive constituent of the Scytonema sp. was less polar in nature and exhibited two peaks at 240 and 285 m. When applied to two cruciffrous pests, Pieris brassicae and Plutella flostella, the crude extracts and toxic principles from the two cyanobacteria showed significant antifeedant activity in a no-choice bioassay, and at higher concenuations exhibited contact toxicity to the insect larvae. The purified toxin from M. aeruginosa was found to be more effective and produced 97.5 and $92.8\%$ larval mortality in the two pests, fo11owing 2 h of toxin treatment at a concentration of $25{\mu}g$ Per leaf disc (2.5 cm dia.). Meanwhile, similar treatment with the purified toxin from Sytonema sp. stain BT 23 only produced 73 and $78\%$ mortality in the two pests. The cyanobacterial constituents also showed significant activity against Culex and Anopheles larvae. The M. aeruginosa toxin ($20{\mu}g\;ml^-1$) caused 98.2 and $88.1\%$ mortality in the Culex and Anopheles larvae, respectively, while the purified toxin from the Sytonema sp. was less toxic and only produced a 96.3 and $91.2\%$ mortality, respectively, at a much higher concentration ($40{\mu}g\;ml^-1$). Accordingly, the current results point to certain hitherto unknown biological properties of cyanobacterial biotoxins.

• Journal of Microbiology and Biotechnology
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• 제19권12호
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• pp.1688-1694
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• 2009

A novel strain of fluorescent pseudomonad (PB-St2) was isolated from surface-sterilized stems of sugarcane grown in Pakistan. The bacterium was identified as Pseudomonas aurantiaca on the basis of 16S rRNA gene sequence analysis and results from physiological and biochemical characteristics carried out with API50 CH and QTS 24 bacterial identification kits. Assays using substrate-specific media for enzymes revealed lipase and protease activities but cellulase, chitinase, or pectinase were not detected. The bacterium was unable to solubilize phosphate or produce indole acetic acid. However, it did produce HCN, siderophores, and homoserine lactones. In dual culture assays on agar, the bacterium showed antifungal activity against an important pathogen of sugarcane in Pakistan, namely Colletotrichum falcatum, as well as for pathogenic isolates of Fusarium oxysporium and F. lateritium but not against F. solani. The antifungal metabolites were identified using thin-layer chromatography, UV spectra, and MALDI-TOFF spectra and shown to be phenazine-1-carboxylic acid (PCA), 2-hydroxyphenazine (2-OH-PHZ), and N-hexanoyl homoserine lactone (HHL) (assessed using only TLC data). The capacity of this bacterium to produce HCN and 2-OH-PHZ, as well as to inhibit the growth of C. falcatum, has not been previously reported.

• Journal of Microbiology and Biotechnology
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• 제23권5호
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• pp.681-688
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• 2013

This work is aimed to increase knowledge of the functional exopolysaccharide (EPS) from lactic acid bacteria (LAB) in makgeolli, a Korean fermented rice wine. Among LAB strains isolated from makgeolli, strain M76 was selected as a functional strain producing a bioactive EPS, based on its antioxidative activity on the DPPH radical. The 16S rRNA gene sequencing analysis showed a high sequence similarity (99.0%) with P. acidilactici, but had different biochemical properties with the already known P. acidilactici type strains in the aspect of carbohydrates utilization. The obtained P. acidilactici M76 produced a soluble EPS above 2 g/l. One-step chromatography using gel filtration after ethanol precipitation from the supernatant of P. acidilactici M76 was enough to obtain purified EPS with a single peak, showing a molecular mass of approximately 67 kDa. Componential and structural analyses of EPS by TLC, HPLC, and FT-IR indicated that the EPS is a glucan, consisting of glucose units. The purified EPS had antioxidant activity on the DPPH radical of 45.8% at a concentration of 1 mg/ml. The purified EPS also showed proliferative effect on the pancreatic RIN-m5F cell line and remarkable protection activity on alloxan-induced cytotoxicity. This potent antioxidant and antidiabetic EPS by LAB in makgeolli may contribute to understanding the functionality of makgeolli.

• 한국미생물·생명공학회지
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• 제30권4호
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• pp.352-358
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• 2002

토양으로부터 maltopentaose생산성 amylase를 분비하는 세균 KSM B-404를 분리하여 그의 형태적, 생리적인 특성을 고려한 결과 Bacillus megaterium으로 동정되었다. 효소는 ($NH_4$)$_2$$SO_4$ 침전 분획, DEAE-Toyopearl 및 Superdex 75 HR 10/30 크로마토그래피로 129배 정제되었으며 21.4%의 활성이 회수되었다. 정제된 효소를 SDS-PACE로 분석한 결과 분자량은 약 68 kDa이었고, 최적 반응 온도는 $50^{\circ}C$이며 $Ca^{2+}$ 이온의 존재 시 열 안정성이 증가하였다. 한편 최적 반응 pH는 6.0~7.0부근이며 알칼리 조건에서도 안정하였다. 또한 효소의 활성은 $Cu^{2+}$ , $Hg^{2+}$ 그리고 특히 Fe/eup 3+/이온 등의 금속이온에 의해 강하게 저해 받았고 acetic anhydride, EDTA , hydroxylamine-HCI, $\rho$ - chloromercuribenzoate 등의 저해제에 의해서 활성이 저해되었으나 concanavalin A에 의한 저해 효과는 나타나지 않았다. 전분의 가수분해 산물을 HPLC로 분석한 결과 maltopentaose가 주산물로 나타났으며 반응 24시간 후 총 가수분해 산물의 약 52%를 차지하였다.