This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Page, W. J. Articles by Stock, J. J. Search for Related Content PubMed Articles by Page, W. J. Articles by Stock, J. J. Agricola Articles by Page, W. J. Articles by Stock, J. J.

 Previous Article  |  Next Article 

Appl Environ Microbiol. 1972 October; 24(4): 650-657
Copyright © 1972 American Society for Microbiology. All Rights Reserved.

Initiation of Dermatophyte Pleomorphic Strain Sporulation by Increased Aeration

Department of Microbiology, The University of British Columbia, Vancouver 8, British Columbia, Canada
Department of Botany, The University of British Columbia, Vancouver 8, British Columbia, Canada

ABSTRACT

A normally asporogenous pleomorphic strain of Microsporum gypseum was induced to sporulate by controlled aeration and dehydration. Aeration of the pleomorphic strain under optimal cultivation conditions caused the initiation of a sporulation cycle with equivalent growth parameters and percentage intracellular water loss as the wild-type strain. Initiation of sporulation was not due to alteration of the medium's nutrient concentration or consistency, concentration of fungal growth by-products, or removal of volatile "staling factors." Macroconidia formed by the pleomorphic colonies were of characteristic wildtype morphology, but germinated to form typical pleomorphic colonies, indicating that the induced sporulation was strictly phenotypic and reversible. Other asporogenous pleomorphic strains from different dermatophyte genera also were induced to form macroconidia by aeration, suggesting a similarity in sporulation induction in Microsporum sp., Epidermophyton floccosum, and Trichophyton violaceum. Initiation of sporulation by aeration further suggested that the pleomorphic mutation was one which affected the sensitivity of the pleomorphic aerial hyphae to natural sporulation inducers (i.e., decreased humidity) and did not represent a loss in the ability to form fertile macroconidia.