Dichloran-rose bengal medium for enumeration and isolation of molds from foods

Appl Environ Microbiol. 1979 May;37(5):959-64. doi: 10.1128/aem.37.5.959-964.1979.

Abstract

Overgrowth by spreading molds such as Rhizopus and Mucor species is a problem with fungal enumeration media used for foods. Thirty-one antifungal compounds were surveyed for their ability to selectively inhibit such fungi while allowing growth of mycotoxigenic molds and other species of significance in food spoilage. Dichloran (2,6 dichloro-4-nitroaniline) restricted growth of Rhizopus stolonifer while allowing satisfactory growth of the other test molds. Three Rhizopus and Mucor species were encountered that were not inhibited by dichloran; these were controlled by the addition of rose bengal. The optimal medium, designated DRBC, contained 2 micrograms of dichloran and 25 micrograms of rose bengal per ml. DRBC, in pure culture tests and with food samples, restricted the colony size of spreading molds and recovered a wider range of species in higher numbers than other enumeration media.

Publication types

  • Comparative Study

MeSH terms

  • Aniline Compounds / pharmacology*
  • Antifungal Agents / pharmacology*
  • Aspergillus / isolation & purification
  • Culture Media*
  • Food Microbiology*
  • Fungi / isolation & purification*
  • Mucor / drug effects
  • Penicillium / isolation & purification
  • Rhizopus / drug effects
  • Rose Bengal / pharmacology
  • Species Specificity

Substances

  • Aniline Compounds
  • Antifungal Agents
  • Culture Media
  • Rose Bengal