Isolation of toxigenic Nocardiopsis strains from indoor environments and description of two new Nocardiopsis Species, N. exhalans sp. nov. and N. umidischolae sp. nov

Appl Environ Microbiol. 2001 Sep;67(9):4293-304. doi: 10.1128/AEM.67.9.4293-4304.2001.


Nocardiopsis strains were isolated from water-damaged indoor environments. Two strains (N. alba subsp. alba 704a and a strain representing a novel species, ES10.1) as well as strains of N. prasina, N. lucentensis, and N. tropica produced methanol-soluble toxins that paralyzed the motility of boar spermatozoa at <30 microg of crude extract (dry weight) x ml(-1). N. prasina, N. lucentensis, N. tropica, and strain ES10.1 caused cessation of motility by dissipating the mitochondrial membrane potential, Deltapsi, of the boar spermatozoa. Indoor strain 704a produced a substance that destroyed cell membrane barrier function and depleted the sperm cells of ATP. Indoor strain 64/93 was antagonistic towards Corynebacterium renale. Two indoor Nocardiopsis strains were xerotolerant, and all five utilized a wide range of substrates. This combined with the production of toxic substances suggests good survival and potential hazard to human health in water-damaged indoor environments. Two new species, Nocardiopsis exhalans sp. nov. (ES10.1T) and Nocardiopsis umidischolae sp. nov. (66/93T), are proposed based on morphology, chemotaxonomic and physiological characters, phylogenetic analysis, and DNA-DNA reassociations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actinomycetales / classification*
  • Actinomycetales / genetics
  • Actinomycetales / isolation & purification*
  • Actinomycetales / metabolism
  • Air Microbiology
  • Air Pollution, Indoor*
  • Animals
  • Bacterial Toxins / metabolism*
  • Bacterial Toxins / toxicity
  • Construction Materials
  • Dust
  • Environmental Monitoring*
  • Fatty Acids / analysis
  • Genes, rRNA
  • Male
  • Molecular Sequence Data
  • Phylogeny
  • Sequence Analysis, DNA
  • Sperm Motility / drug effects
  • Spermatozoa / drug effects
  • Swine


  • Bacterial Toxins
  • Dust
  • Fatty Acids

Associated data

  • GENBANK/AF105971
  • GENBANK/AF105972
  • GENBANK/AY036001
  • GENBANK/AY036002
  • GENBANK/AY036003
  • GENBANK/AY036004