Biological evaluation of neopeptins isolated from a Streptomyces strain

Sung Kim Yun, Min Kim Hyeong, Cheol Chang, Cheon Hwang In, Hyuncheol Oh, Seog Ahn Jong, Deok Kim Ki, Kook Hwang Byung, Seok Kim Beom

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

BACKGROUND: Microbial secondary metabolites are a rich source of antifungal agents and have merit as alternatives to synthetic fungicides. To develop disease control agents against powdery mildew, the lipopeptide antibiotic neopeptins were identified from the culture broth of a Streptomyces sp., and in vivo control efficacy of the compounds was evaluated on cucumber plants under glasshouse conditions. RESULTS: The Streptomyces sp. KNF2047 antagonistic against powdery mildew development in cucumber plants was isolated from a soil sample. Antifungal compounds were purified from the culture broth and identified as neopeptin A and B. In vitro microtitre assays revealed the inhibitory activities of the compounds in the range 128-512 μg mL-1 against the mycelial growth of Alternaria mali, Botrytis cinerea, Cladosporium cucumerinum, Colletotrichum lagenarium, Didimella bryoniae and Magnaporthe grisea. Although neither compound showed remarkable in vitro antifungal activity against other plant pathogenic fungi, a mixture of neopeptins (484 mg of neopeptin A and 290 mg of neopeptin B per gram of partially purified powder) showed potent protective and curative activity against cucumber powdery mildew in vivo. The disease control activity of the neopeptins at a concentration of 2.4 mg L-1 was 92.1%, which was similar to that of the commercial fungicide fenarimol (89.3% at 63 mg L-1) and that of the commercial biocontrol agent Actinovate (67.4% at 2 × 107 cfu L -1). CONCLUSION: Neopeptin mixtures isolated from Streptomyces sp. KNF2047 showed potent disease control activity against powdery mildew development on cucumber plants.

Original languageEnglish
Pages (from-to)1208-1214
Number of pages7
JournalPest Management Science
Volume63
Issue number12
DOIs
Publication statusPublished - 2007 Dec

Keywords

  • Antifungal agent
  • Neopeptins
  • Powdery mildew
  • Sphaerotheca fusca
  • Streptomyces sp.

ASJC Scopus subject areas

  • Agronomy and Crop Science
  • Insect Science

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