• Journal of Life Science
• /
• v.14 no.1
• /
• pp.193-197
• /
• 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.

• Korean Journal of Microbiology
• /
• v.54 no.3
• /
• pp.244-253
• /
• 2018

This study was carried out to evaluate effects of antimicrobial substances produced by isolated soil bacteria. Among two thousands of bacterial isolates Paenibacillus elgii DS381 exhibited high antimicrobial activities against several microbial residents on human skin and pathogenic bacteria. DS381 showed 15.3~26.0 mm inhibition zone diameter against all target bacteria and yeast in agar well diffusion test. Antimicrobial peptide produced by DS381 indicated low minimum inhibitory concentration (0.039-5.000 mg/ml). DS381 produced biosurfactant such as lipopeptide, and surface tension of culture supernatant of DS381 reduced from 60.0 to 40.3 mN/m. DS381 also showed $1.56{\pm}0.13U/ml$ of chitinase activity. These results suggest that Paenibacillus elgii DS381 may be utilized as an efficient biocontrol agent against some important human skin microbes and pathogenic bacteria.

• 한국생물공학회:학술대회논문집
• /
• 2003.04a
• /
• pp.240-244
• /
• 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
• /
• v.25 no.11
• /
• pp.1954-1959
• /
• 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.

• Microbiology and Biotechnology Letters
• /
• v.21 no.6
• /
• pp.556-563
• /
• 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
• /
• v.21 no.4
• /
• pp.319-323
• /
• 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.

• Proceedings of the Korean Society of Life Science Conference
• /
• 2006.09a
• /
• pp.80.2-80.2
• /
• 2006

• Proceedings of the Korean Society of Life Science Conference
• /
• 2003.10a
• /
• pp.87-87
• /
• 2003

• Proceedings of the Korean Society of Life Science Conference
• /
• 2007.10a
• /
• pp.74.1-74.1
• /
• 2007

See Full Text

• Proceedings of the Korea Environmental Mutagen Society Conference
• /
• 2004.05a
• /
• pp.93-93
• /
• 2004