Biological control agent of common scab disease by antagonistic strain Bacillus sp. sunhua.
OBJECTIVE
To identify an antagonistic strain against Streptomyces scabiei and to characterize the antibiotic agent. The efficacy of the isolated strain in controlling common scab disease was also evaluated.


RESULTS
A bacterial strain antagonistic against S. scabiei was isolated from the soil of a potato-cultivating area. This bacterium was identified as a Bacillus species by 16S rRNA gene sequence analysis and was designated Bacillus sp. sunhua. Antibiotics produced by this strain were proven to be stable within a broad pH range and at high temperatures. The culture broth was extracted with ethyl acetate, and then the crude extract was applied to HPLC. Two compounds were isolated and identified as iturin A and macrolactin A by 1H-NMR, 13C-NMR, HMBC, HMQC and mass spectrometer. The culture broth of Bacillus sp. sunhua had a suppressive effect on common scab disease in a pot assay, decreasing the infection rate from 75 to 35%. This strain also suppressed Fusarium oxysporum, the pathogen of potato dry rot disease.


CONCLUSIONS
Bacillus sp. sunhua was shown to inhibit S. scabiei effectively.


CONCLUSIONS
This is the first report demonstrating that macrolactin A and iturin A inhibit S. scabiei. This study demonstrated the possibility of controlling potato scab disease using Bacillus sp. sunhua.
Han
J S
JS
Department of Biological Science, Institute of Bioscience and Biotechnology, Myongji University, Yongin, Korea.
Cheng
J H
JH
Yoon
T M
TM
Song
J
J
Rajkarnikar
A
A
Kim
W G
WG
Yoo
I D
ID
Yang
Y Y
YY
Suh
J W
JW
D000900:Anti-Bacterial Agents / Q000032:analysis*; D000935:Antifungal Agents / Q000032:analysis; D001407:Bacillus / Q000502:physiology*; D001483:Base Sequence; D001681:Biological Assay / Q000379:methods; D002474:Cell-Free System; D006863:Hydrogen-Ion Concentration; D018942:Macrolides / Q000032:analysis; D008855:Microscopy, Electron, Scanning / Q000379:methods; D010455:Peptides / Q000032:analysis; D010456:Peptides, Cyclic; D010572:Pest Control, Biological / Q000379:methods; D010935:Plant Diseases / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000032:analysis; D012988:Soil Microbiology; D011198:Solanum tuberosum; D013171:Spores, Bacterial / Q000187:drug effects / Q000254:growth & development; D013302:Streptomyces / Q000187:drug effects* / Q000254:growth & development / Q000648:ultrastructure; D013696:Temperature
D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D018942:Macrolides; D010455:Peptides; D010456:Peptides, Cyclic; D012336:RNA, Ribosomal, 16S; C453562:macrolactin A; C013579:iturin A