PubAg

Main content area

Evaluation of the chitin-binding dye Congo red as a selection agent for the isolation, classification, and enumeration of ascomycete yeasts

Author:
Linder, Tomas
Source:
Archives of microbiology 2018 v.200 no.4 pp. 671-675
ISSN:
0302-8933
Subject:
Ascomycota, dyes, phenotype, yeasts
Abstract:
Thirty-nine strains of ascomycete yeasts representing 35 species and 33 genera were tested for their ability to grow on solid agar medium containing increasing concentrations of the chitin-binding dye Congo red. Six strains were classified as hypersensitive (weak or no growth at 10 mg/l Congo red), five were moderately sensitive (weak or no growth at 50 mg/l), three were moderately tolerant (weak or no growth at 100 mg/l), while the remaining 25 strains were classified as resistant (robust growth at ≥ 100 mg/l) with 20 of these strains classified as hyper-resistant (robust growth at 200 mg/l). Congo red growth phenotypes were consistent within some families but not others. The frequency of Congo red resistance among ascomycete yeasts was deemed too high for the practical use of Congo red as a selection agent for targeted isolation, but can be useful for identification and enumeration of yeasts.
Agid:
5931824