Streptomyces strains producing mitochondriotoxic antimycin A found in cereal grains

Stiina Rasimus-Sahari*, Raimo Mikkola, Maria A. Andersson, Marika Jestoi, Mirja Salkinoja-Salonen

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

5 Citations (Scopus)

Abstract

Reasons for mammalian cell toxicity observed in barley and spring wheat grains were sought. Streptomyces sp. isolates from wheat and barley produced heat-stable methanol-soluble substances which inhibited the motility of exposed porcine spermatozoa used as a toxicity indicator. Several barley isolates produced antimycin A (2 to 5 ng/mg wet wt of biomass), a macrolide antibiotic known to block oxygen utilization in mitochondria. The antimycin-producing isolates were members of the Streptomyces albidoflavus group. In in vitro assays with porcine kidney tubular epithelial cells, the specific toxicity of antimycin A towards mitochondria was higher than that of the mycotoxin enniatin B but lower than that of the mitochondriotoxins cereulide and paenilide, produced by food-related Bacillus cereus and Paenibacillus tundrae, respectively. The toxic wheat isolates, related to Streptomyces sedi, did not produce antimycin A and or any other known toxin. Our results suggest that the presence of toxin-producing streptomycetes in stored cereal grains may pose a thus far unrecognized threat for food and feed safety. (C) 2015 Elsevier B.V. All rights reserved.

Original languageEnglish
Pages (from-to)78-85
Number of pages8
JournalInternational Journal of Food Microbiology
Volume218
DOIs
Publication statusPublished - 2 Feb 2016
MoE publication typeA1 Journal article-refereed

Keywords

  • Streptomyces albidoflavus
  • Antimycin A
  • Cereal grains
  • Mitochondriotoxic
  • Food safety
  • Enniatin B
  • BACILLUS-CEREUS
  • ALTERNATIVE OXIDASE
  • IN-VITRO
  • FUSARIUM MYCOTOXINS
  • GENUS STREPTOMYCES
  • TOXICITY
  • FOOD
  • ACTINOBACTERIA
  • IDENTIFICATION
  • CYTOTOXICITY

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