• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2777-2780
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• 2012

• 생명과학회지
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• 제14권1호
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• pp.193-197
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• 2004

A continuous enrichment culture procedure was used to isolate bacteria from various soil sources capable of suppressing large patch disease of turfgrass. Six isolates consistently suppressed large patch in turfgrass, and ranged in the spectrum of extracellular enzymes that they expressed. The best disease- suppressing isolate, TBM912, expressed protease, CMCase, and pectinase activity and inhibited the growth of Rhizectonin solani and Betrytis cinerea in vitro. Here we show that this strain also produces an antibiotic that was identified by TLC, SDS-PACE and HPLC analysis as lipopeptide.

• 미생물학회지
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• 제54권3호
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• pp.244-253
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• 2018

이 연구는 분리된 토양 세균에 의해 생성된 항균물질의 효과를 평가하기 위해 수행되었다. 2000여개의 세균 분리주 중 Paenibacillus elgii DS381이 여러 인간 피부 상재균과 병원성 세균에 대해 높은 항균활성을 나타내었다. DS381 균주는 agar well diffusion test에서 모든 대상 세균과 효모에 대해 15.3~26.0 mm 직경의 저해대를 형성하였다. DS381이 생성한 항균 펩티드는 모든 대상 미생물에 낮은 최소저해농도 (0.039-5.000 mg/ml)를 나타내었다. DS381 균주는 lipopeptide 같은 생물계면활성제 생산을 나타내었는데, 배양 상등액의 표면장력을 60.0에서 40.3 mN/m으로 낮추었다. DS381은 또한 $1.56{\pm}0.13U/ml$의 chitinase 활성도 나타내었다. 이 결과들은 P. elgii DS381이 일부 중요한 인간 피부 상재균과 병원성 세균에 대한 효율적인 생물제어제로 사용될 수 있음을 가리킨다.

• Journal of Microbiology and Biotechnology
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• 제34권5호
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• pp.1029-1039
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• 2024

This study explores beneficial bacteria isolated from the roots and rhizosphere soil of Khao Rai Leum Pua Phetchabun rice plants. A total of 315 bacterial isolates (KK001 to KK315) were obtained. Plant growth-promoting traits (phosphate solubilization and indole-3-acetic acid (IAA) production), and antimicrobial activity against three rice pathogens (Curvularia lunata NUF001, Bipolaris oryzae 2464, and Xanthomonas oryzae pv. oryzae) were assessed. KK074 was the most prolific in IAA production, generating 362.6 ± 28.0 ㎍/ml, and KK007 excelled in tricalcium phosphate solubilization, achieving 714.2 ± 12.1 ㎍/ml. In antimicrobial assays using the dual culture method, KK024 and KK281 exhibited strong inhibitory activity against C. lunata, and KK269 was particularly effective against B. oryzae. In the evaluation of antimicrobial metabolite production, KK281 and KK288 exhibited strong antifungal activities in cell-free supernatants. Given the superior performance of KK281, taxonomically identified as Bacillus sp. KK281, it was investigated further. Lipopeptide extracts from KK281 had significant antimicrobial activity against C. lunata and a minimum inhibitory concentration (MIC) of 3.1 mg/ml against X. oryzae pv. oryzae. LC-ESI-MS/MS analysis revealed the presence of surfactin in the lipopeptide extract. The crude extract was non-cytotoxic to the L-929 cell line at tested concentrations. In conclusion, the in vitro plant growth-promoting and disease-controlling attributes of Bacillus sp. KK281 make it a strong candidate for field evaluation to boost plant growth and manage disease in upland rice.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.240-244
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• 2003

A novel integrated method for increasing dissolved oxygen concentration in culture media has been developed. It involves adding hydrogen peroxide to the medium, which is then decomposed to oxygen and water by catalase and adding vegetable oil to the medium as antifoam agent and oxygen vector. A new apparatus for automated addition of hydrogen peroxide to the bioreactor to keep the dissolved oxygen concentration constant over the range $10-100%\;{\pm}\;5%$ was tested. A significant increase (over threefold) of cultivation time was obtained while the dissolved oxygen concentration remained stable ($30%\;{\pm}\;5%$). Therefore, use of corn oil mixed with Ca-stearate as oxygen vector and antifoam and hydrogen peroxide as oxygen source to control excessive foam that was generated by microorganism biosurfactant, GB16-BS produced at Bacillus sp. GB16 cultivation was appropriate for stable cultivation.

• Journal of Microbiology and Biotechnology
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• 제25권11호
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• pp.1954-1959
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• 2015

Bacillus subtilis HM1 was isolated from the rhizosphere region of halophytes for its antifungal activity against Colletotrichum acutatum, the causative agent of anthracnose. Treatment of postharvest apples with the cell culture or with a cell-free culture supernatant reduced disease severity 80.7% and 69.4%, respectively. Both treatments also exhibited antifungal activity against various phytopathogenic fungi in vitro. The antifungal substances were purified and analyzed by acid precipitation, gel filtration, high-performance liquid chromatography, and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Three compounds were identified as fengycin, iturin, and surfactin. The MALDI-TOF/TOF mass spectrum revealed the presence of cyclized fengycin homologs A and B, which were distinguishable on the basis of the presence of either alanine or valine, respectively, at position 6 of the peptide sequence. In addition, the cyclized structure of fengycin was shown to play a critical role in antifungal activity.

• 한국미생물·생명공학회지
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• 제21권6호
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• pp.556-563
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• 1993

AF-011A is a novel lipopeptide with potent antifungal activity isolated from Pseudomonas cepacia AF6008 deposited as KFCC 10759. The compound was isolated from the fermentation broth by extraction with 50% isopropyl alcohol. Purification was effected by chromatography on Diaion HP-20, Alumina and C18 followed by HPTLC on silica gel. These techniques affored two closelt related compounds. AF-011A1 ans AF-011A2. The molecular weights of AF-011A1/A2 were determined by fast atom bombardment mass spectrometry(A1 m/z 1,215 : A2 m/z 1,199).

• Toxicological Research
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• 제21권4호
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• pp.319-323
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• 2005

The aim of the present study was to evaluate systemic bioavailability of surfactin and to determine its pharmacokinetic profiles. The stability of surfactin to pH, temperature and protease was evaluated. Surfactin was resistant to high temperature, a wide range of pH and the action of hydrolytic enzymes. The pharmacokinetic natures of surfactin which were shown the short half-life, rapid clearance and poor bioavailability. The results of study should provide preliminary data of surfactin for further dose-finding studies and for the design of application forms. It is also be important to a context of the safety of surfactin.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2006년도 제47회 학술심포지움 및 추계국제학술대회
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• pp.80.2-80.2
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• 2006

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2003년도 제40회 국제학술심포지움
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• pp.87-87
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• 2003