• Mycobiology
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• 제41권4호
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• pp.234-242
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• 2013

A total of 62 bacterial isolates were obtained from Gomsohang mud flat, Mohang mud flat, and Jeju Island, Republic of Korea. Among them, the isolate CNU114001 showed significant antagonistic activity against pathogenic fungi by dual culture method. The isolate CNU114001 was identified as Bacillus amyloliquefaciens by morphological observation and molecular data analysis, including 16SrDNA and gyraseA (gyrA) gene sequences. Antifungal substances of the isolate were extracted and purified by silica gel column chromatography, thin layer chromatography, and high performance liquid chromatography. The heat and UV ray stable compound was identified as iturin, a lipopeptide (LP). The isolate CNU114001 showed broad spectrum activity against 12 phytopathogenic fungi by dual culture method. The semi purified compound significantly inhibits the mycelial growth of pathogenic fungi (Alternaria panax, Botrytis cinera, Colletotrichum orbiculare, Penicillium digitatum, Pyricularia grisea and Sclerotinia sclerotiorum) at 200 ppm concentration. Spore germ tube elongation of Botrytis cinerea was inhibited by culture filtrate of the isolate. Crude antifungal substance showed antagonistic activity against cucumber scleotiorum rot in laboratory, and showed antagonistic activity against tomato gray mold, cucumber, and pumpkin powdery mildew in greenhouse condition.

• The Plant Pathology Journal
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• 제35권5호
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• pp.425-436
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• 2019

Botrytis cinerea, a major phytopathogenic fungus, has been reported to infect more than 200 crop species worldwide, and it causes massive losses in yield. The aim of this study was to evaluate the inhibitory abilities and effects of Bacillus amyloliquefaciens RS-25, Bacillus licheniformis MG-4, Bacillus subtilis Z-14, and Bacillus subtilis Pnf-4 and their culture filtrates and extracts against the gray mold caused by B. cinerea on postharvest tomato, strawberry, and grapefruit. The results revealed that the cells of Z-14, culture filtrate of RS-25, and cells of Z-14 showed the strongest biocontrol activity against the gray mold on the strawberry, grape, and tomato fruit, respectively. All the strains produced volatile organic compounds (VOCs), and the VOCs of Pnf-4 displayed the highest inhibition values. Based on headspace solid-phase microextraction in combination with gas chromatography-mass spectrometry, esters accounted for the largest percentage of the VOCs produced by RS-25, MG-4, Z-14, and Pnf-4 (36.80%, 29.58%, 30.78%, and 36.26%, respectively). All the strains showed potent cellulase and protease activities, but no chitinase activity. RS-25, Z-14, and MG-4, but not Pnf-4, grew on chrome azurol S agar, and an orange halo was formed around the colonies. All the strains showed biofilm formation, fruit colonization, and lipopeptide production, which may be the main modes of action of the antagonists against B. cinerea on the fruit. This study provides the basis for developing natural biocontrol agents against the gray mold caused by B. cinerea on postharvest fruit.

• Journal of Veterinary Science
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• 제24권5호
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• pp.69.1-69.11
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• 2023

Background: Kalkitoxin (KT) is an active lipopeptide isolated from the cyanobacterium Lyngbya majuscula found in the bed of the coral reef. Although KT suppresses cell division and inflammation, KT's mechanism of action in vascular smooth muscle cells (VSMCs) is unidentified. Therefore, our main aim was to investigate the impact of KT on vascular calcification for the treatment of cardiovascular disease. Objectives: Using diverse calcification media, we studied the effect of KT on VSMC calcification and the underlying mechanism of this effect. Methods: VSMC was isolated from the 6 weeks ICR mice. Then VSMCs were treated with different concentrations of KT to check the cell viability. Alizarin red and von Kossa staining were carried out to examine the calcium deposition on VSMC. Thoracic aorta of 6 weeks mice were taken and treated with different concentrations of KT, and H and E staining was performed. Real-time polymerase chain reaction and western blot were performed to examine KT's effect on VSMC mineralization. Calcium deposition on VSMC was examined with a calcium deposition quantification kit. Results: Calcium deposition, Alizarin red, and von Kossa staining revealed that KT reduced inorganic phosphate-induced calcification phenotypes. KT also reduced Ca⁺⁺-induced calcification by inhibiting genes that regulate osteoblast differentiation, such as runtrelated transcription factor 2 (RUNX-2), SMAD family member 4, osterix, collagen 1α, and osteopontin. Also, KT repressed Ca²⁺-induced bone morphogenetic protein 2, RUNX-2, collagen 1α, osteoprotegerin, and smooth muscle actin protein expression. Likewise, Alizarin red and von Kossa staining showed that KT markedly decreased the calcification of ex vivo ring formation in the mouse thoracic aorta. Conclusions: This experiment demonstrated that KT decreases vascular calcification and may be developed as a new therapeutic treatment for vascular calcification and arteriosclerosis.

• Journal of Applied Biological Chemistry
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• 제54권4호
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• pp.279-283
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• 2011

염증의 중요한 분자학적 기전에는 cyclooxygenase-2 (COX-2)에 의한 prostaglandins (PGs) 생성과 inducible nitric oxide synthase (iNOS)에 의한 nitric oxide (NO) 생성이 있다. 많은 종류의 박테리아나 바이러스가 전사요소인 nuclear factor-${\kappa}$B(NF-${\kappa}$B)를 활성화시켜 여러 타깃 유전자의 발현을 조절해 PGs나 NO와 같은 염증물질을 유도하게 된다. 우리는 이번 실험을 통하여 phenethyl isothiocyanate (PEITC)가 toll-like receptor(TLR) agonists에 의해 유도된 NF-${\kappa}$B활성과 COX-2, iNOS 발현에 어떠한 영향을 미치는지 알아 보았다. PEITC는 lipopolysaccharide (LPS)와 polyinosinic-polycytidylic acid (poly[I:C])에 의해 유도된 NF-${\kappa}$B활성을 억제시켰다. 또한 PEITC는 LPS와 Poly[I:C]에 의해 유도된 iNOS의 발현도 억제시켰다. 하지만 PEITC는 TLR agonists들인 LPS, Poly[I:C], 2 kDa macrophage-activating lipopeptide (MALP-2), oligodeoxynucleotide 1668 (ODN1668)에 의한 COX-2 발현은 억제시키지 못하였다. 즉 PEITC가 TRIF-dependent 신호전달체계만을 조절하여 TRIF-dependent 신호전달체계에 의해 조절되는 iNOS는 억제하지만 MyD88-dependent 신호전달 체계에 의해 조절되는 COX-2는 억제하지 못한다는 것을 설명해준다. 이러한 결과는 iNOS와 COX-2가 서로 다른 메커니즘에 의해 조절된다는 것을 암시하며, PEITC가 여러 병원균들로부터 유도되는 염증반응이나 만성적인 질병들을 조절할 수 있음을 제시하는 중요한 결과이다.

• 생명과학회지
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• 제25권8호
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• pp.910-916
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• 2015

최근 식물 성장에 있어 곰팡이 독소에 관련된 질병에 효과가 있는 Bacillus mojavensis 균주 사용의 보고가 있다. 우리는 B. mojavensis KJS-3균주의 다양한 온도, 염도, 에탄올, pH에서 성장하는 특징을 확인 하였다. B. mojavensis KJS-3균주는 Polymerase chain reaction 분석에 의해 fengycin을 LC-MS/MS 분석을 통해서는 iturin 및 surfactin 와 같은 cyclic lipopeptides를 생산함을 확인 하였다. B. mojavensis KJS-3균주는 식물 유해 곰팡이 균주인 Botrytis cinerea, Rhizoctonia solani AG-4, Sclerotinia sclerotiorum, Colletotricum goeosporioides에 항곰팡이 효과가 있음을 확인하였고 이 결과를 바탕으로 인삼재배에 있어 B. mojavensis KJS-3를 사용하여 성장을 관찰한 결과 뿌리 내에서 성장하여 plant growth promoting endophyte가 있음을 알 수 있었다. 이러한 특징들에 의해 미생물 농약 및 비료로 사용할 수 있을 것이다.

• 한국식품과학회지
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• 제39권2호
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• pp.175-180
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• 2007

TLRs는 병원균이 숙주의 몸 속에 들어 왔을 때, 병원균들이 가지고 있는 독특한 구조를 인식하여 선천성 면역반응과 뒤이어 후천성 면역반응을 유도하는 중요한 역할을 한다. 우리는 이번 실험을 통하여 curcumin이 선행연구에서 밝혀낸 TLR4 뿐만 아니라 TLR2와 TLR6 그리고 TLR3를 또한 분자학적인 타깃으로 할 수 있다는 것을 알아내었다. Curcumin이 MALP-2(TLR2,6 agonist)에 의해서 유도된 IRAK-1 degradation을 억제시켰다. 이러한 결과는 curcumin의 분자학적인 타깃이 IRAK-1위에 놓여 있으며, TLR2와 TLR6가 될 것이라는 가능성을 제시해 준다고 할 수 있다. 또한 curcumin은 viral 자극제인 poly[I:C](TLR3 agonist)에 의해서 유도된 IRF3나 $NF-{\kappa}B$ 활성화를 억제하였지만, TRIF에 의해서 유도된 IRF3 활성화는 억제시키지를 못하였다. 이러한 결과 또한 TLR3 자체가 curcumin의 분자학적인 타깃이라는 가능성을 제시해 준다고 할 수 있겠다. 이러한 결과를 종합해 볼때, curcumin의 분자학적인 타깃이 $IKK{\beta}$ 이외에 모든 TLRs가 될 수 있다는 가능성을 제시해 준다고 할 수 있겠다. 이러한 결과는 curcumin이 그람음성균 뿐만이 아니라 바이러스나 박테리아 등 여러 병원균들로부터 유도되는 염증반응이나 만성적인 질병들을 조절할 수 있다는 것을 보여주는 결과라 할 수 있겠다.

• 한국미생물·생명공학회지
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• 제44권1호
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• pp.9-18
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• 2016

청국장에서 강력한 항균력을 지닌 2개의 Bacillus 균주들인 CJW15와 SSD8이 분리되었다. 16S rRNA와 recA 유전자들 염기서열 결정에 의해 두가지 균주 모두 B. amyloliquefaciens로 동정되었다. CJW15는 B. cereus ATCC14579, Listeria monocytogenes ATCC19111, Lactococcus lactis ATCC11454 들의 증식을 강력히 억제하며 SSD8은 B. cereus ATCC14579와 Enterococcus faecium ATCC19953 증식을 억제하였다. 두 균주들의 항균력은 $100^{\circ}C$, 15분 처리에도 감소하지 않았고 산성인 pH 3과 알칼리인 pH 12에서도 안정하였다. 트립신, 펩신, 프로테아제 K, 프로테아제 효소처리에 의해 CJW15 항균력은 변화가 없었지만 SSD8 항균력은 절반으로 감소하였다. 두 균주 공히 surfactin, fengycin, iturin, iturinA와 같은 lipopeptide 생합성 유전자들을 지니고 있고 subtilin과 같은 박테리오신 유전자들도 지니고 있다. 또 두 균주들은 혈전용해능을 지니고 있다.

• Journal of Microbiology and Biotechnology
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• 제27권3호
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• pp.480-491
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• 2017

Fluorescent pseudomonads have been isolated from halophytes, mesophytes, and xerophytes of Pakistan. Among these, eight isolates, GS-1, GS-3, GS-4, GS-6, GS-7, FS-2 (cactus), ARS-38 (cotton), and RP-4 (para grass), showed antifungal activity and were selected for detailed study. Based on biochemical tests and 16S rRNA gene sequences, these were identified as strains of P. chlororaphis subsp. chlororaphis and aurantiaca. Secondary metabolites of these strains were analyzed by LC-MS. Phenazine-1-carboxylic acid (PCA), 2-hydroxy-phenazine, Cyclic Lipopeptide (white line-inducing principle (WLIP)), and lahorenoic acid A were detected in variable amounts in these strains. P. aurantiaca PB-St2 was used as a reference as it is known for the production of these compounds. The phzO and PCA genes were amplified to assure that production of these compounds is not an artifact. Indole acetic acid production was confirmed and quantified by HPLC. HCN and siderophore production by all strains was observed by plate assays. These strains did not solubilize phosphate, but five strains were positive for zinc solubilization. Wheat seedlings were inoculated with these strains to observe their effect on plant growth. P. aurantiaca strains PB-St2 and GS-6 and P. chlororaphis RP-4 significantly increased both root and shoot dry weights, as compared with uninoculated plants. However, P. aurantiaca strains FS-2 and ARS-38 significantly increased root and shoot dry weights, respectively. All strains except PB-St2 and ARS-38 significantly increased the root length. This is the first report of the isolation of P. aurantiaca from cotton and cactus, P. chlororaphis from para grass, WLIP and lahorenoic acid A production by P. chlororaphis, and zinc solubilization by P. chlororaphis and P. aurantiaca.

• Journal of Microbiology and Biotechnology
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• 제20권2호
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• pp.301-310
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• 2010

Bacillus subtilis strains produce a broad spectrum of bioactive peptides. The lipopeptide surfactin belongs to one well-known class, which includes amphiphilic membrane-active biosurfactants and peptide antibiotics. Both the srfA promoter and the ComP-ComA signal transduction system are an important part of the factor that results in the production of surfactin. Bs-M49, obtained by means of low-energy ion implantation in wild-type Bs-916, produced significantly lower levels of surfactin, and had no obvious effects against R. solani. Occasionally, we found strain Bs-M49 decreased spore formation and the development of competence. Blast comparison of the sequences from Bs-916 and M49 indicate that there is no difference in the srfA operon promoter PsrfA, but there are differences in the coding sequence of the comA gene. These differences result in three missense mutations within the M49 ComA protein. RT-PCR analyses results showed that the expression levels of selected genes involved in competence and sporulation in both the wild-type Bs-916 and mutant M49 strains were significantly different. When we integrated the comA ORF into the chromosome of M49 at the amyE locus, M49 restored hemolytic activity and antifungal activity. Then, HPLC analyses results also showed the comA-complemented strain had a similar ability to produce surf actin with wild-type strain Bs-916. These data suggested that the mutation of three key amino acids in ComA greatly affected the biological activity of Bacillus subtilis. ComA protein 3D structure prediction and motif search prediction indicated that ComA has two obvious motifs common to response regulator proteins, which are the N-terminal response regulator receiver motif and the C-terminal helix-turn-helix motif. The three residues in the ComA N-terminal portion may be involved in phosphorylation activation mechanism. These structural prediction results implicate that three mutated residues in the ComA protein may play an important role in the formation of a salt-bridge to the phosphoryl group keeping active conformation to subsequent regulation of the expression of downstream genes.

• 식물병연구
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• 제23권2호
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• pp.177-185
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• 2017

장수풍뎅이 유충의 장내세포에서 분리한 Bacillus amyloliquefaciens LM11은 surfactin, iturin, fengycin 같은 biosurfactants lipopeptide를 생산하여 식물병원성 곰팡이의 성장을 강하게 억제하였다. LM11균주 성장단계에 따라 biosurfactant 생산과 surface tension은 상당히 유의한 차이가 있었다. 항균 물질인 surfactin, iturin, fengycin의 생합성 유전자는 정지기에 도달하면서 집중적으로 발현되었고 그 생산량도 높았다. 또한 LM11균주를 제거한 배양 상등액 함량의 농도에 따라 고추 탄저병원균의 포자발아와 높은 부의 상관관계가 있었다(R=0.761, P<0.001). 식물병원성 곰팡이의 균사 생장억제를 위한 최소 surface tension 수준은 38.5 mN/m였다(R=0.951-0.977, P<0.001). 본 연구 결과는 B. amyloliquefaciens LM11의 biosurfactant가 식물병에 대한 생물학적 방제에 중요한 항진균 대사물질로 작용하며, 배양액의 surface tension 측정은 생물학적 방제제의 최적 사용을 위한 기초 지표로 사용될 수 있음을 보여 주었다.