Growth Media

Contents
Hay infusion agar
Modified Dixon's agar (mDixon)
Sabouraud agar or Sabouraud's dextrose agar (SDA)

Hay infusion agar

 

Applications

Hay infusion agar is a nutrient deficient medium, which can be used for subcultivation of fungi (for instance Actinomortierella wolfii), to get them to sporulate.

The medium contains:

  • partially decomposed hay
  • di-potassium hydrogen phosphate  (K2HPO4)
  • agar (solidfying agent)
  • H2O

The final pH of the medium should be 6.2.

Updated: 2021-01-14.

Contents

Modified Dixon's agar (mDixon)

 

Applications:

Dixon's agar is mainly used for growing Malassezia furfur, but a modified variant (mDixon) can also be used for growing other dermatophytes.

The medium contains:

  • malt extract (contains nutrients)
  • peptone (enzymatic degradation products of animal tissue or milk, which are also a sources of various nutrients)
  • desiccated beef bile, which contains various bile acids
  • Tween 40
  • glycerol monooleat, which is a source of oleic acid
  • agar (gelifying agent)
  • H2O

The pH of the medium should be 6.0.

Other comments:

Most Malassezia species (except M. pachydermatis) are lipophilic i.e. they require the addition of lipids to the culture medium. Other dermatophytes can also be grown in mDixon.

Updated: 2021-09-16.

Contents

Sabouraud agar or Sabouraud's dextrose agar (SDA)

Sabaroud agar

Image A shows a plate containing Sabouraud Agar before cultivation. Image B shows the same kind of plate on which Hanseniaspora uvarum has been cultivated at 30°C during 5 days.  - Click on the image to enlarge it (opens in a new window/tab).

Image: Ingrid Hansson (BVF,SLU), Lise-Lotte Fernström (BVF, SLU) and Karl-Erik Johansson (BVF, SLU).

Use

Sabouraud agar is mainly used to grow dermatophytes and other types of yeasts and molds. Sabaroudagar can also be used to grow filamentous bacteria, e.g. species within the genus Nocardia.

The medium contains:

  •  dextrose (which is another name for D-glucose)
  •  peptone (hydrolyzed proteins, which contains short peptodes and amino acids)
  •  agar (jelly-forming substance)

The pH of the medium should be 5.6 and this relatively low pH inhibits the growth of many bacteria.

Other comments

This medium is not always recommended for primary isolation, as it is not nutritious enough for some fastidious fungi. This is especially true for many of the dimorphic fungi.

Updated: 2021-05-14.

Contents

Recently Updated

Swedish University of Agricultural Sciences