First, to define the mold and yeast cultivation environment, we need to have information about molds and yeasts. Mold and yeast are widely present in our surroundings. For this reason, the study and knowledge of yeasts and molds has received more attention today.

Molds

Molds have little competitive power, and for this reason, they can only grow in the environment when the growth conditions are not favorable for other microorganisms. Among these conditions can be:

• Low pH
• The presence of a large amount of salt and sugar in the environment
• low humidity
• The presence of antibiotics

Due to the presence of numerous enzymes, molds can consume proteins from carbohydrates, pectins, lipids and organic acids.

yeasts

Identification of yeasts in the microorganism bank is done according to the reference standard for yeast identification (5th edition of The Yeasts, A Taxonomic Study). Classification of yeasts is divided into two groups, ascomycetes and basidomycetes, based on the ability to produce urease from the DBB reaction. Yeasts are examined morphologically and micromorphologically. In the examination of the morphology of yeasts, based on characteristics such as the color and shape of the colony, texture, border and changes in the color spectrum in a specific time unit, while in the examination of micromorphology, the size and shape of the cell are examined in terms of bud production and its shape. will be

Some dedicated culture environments

• (Yeast Extract Glucose Cholranphenicol Agar (YGC
• Sabouraud Dextrose Agar (SDA).
• Potato Dextrose Agar
• Fungi Agar Base
• Corn meal agar
• Oxytetracyline Glucose yeast agar

A closer look at mold and yeast cultures

• (Yeast Extract Glucose Cholranphenicol Agar (YGC:

Due to the presence of yeast extract and nutrients necessary for growth, glucose as a carbon source and chloramphenicol as an inhibitor of bacterial growth, this culture medium is considered a suitable substrate for the cultivation of molds and yeasts.

• Sabouraud Dextrose Agar (SDA).

Sabro dextrose agar culture medium is a selective culture medium with an acidic pH of 5.6 for the cultivation and isolation of fungi and yeasts, dermatophytes and filamentous bacteria such as Nocardia. The existence of a high concentration of dextrose, a fermentable carbohydrate as a carbon source, and the addition of antibiotics such as gentamicin, tetracycline, penicillin, and chloramphenicol are considered as selective factors.

• Potato Dextrose Agar

Potato Dextrose Agar or PDA culture medium is one of the widely used culture mediums for isolating and counting molds and yeasts in cosmetic and clinical samples, which is made from the combination of potato and dextrose. The presence of potato nutrients is a factor for sporulation in molds and pigment production in some dermatophytes.

• Fungi Agar Base

Fungi Agar culture medium containing soybean peptone, nitrogen, minerals and some vitamins provides a suitable substrate for the growth of bacteria. Also, the presence of dextrose in the environment is used as a carb source.

• Corn meal agar

As the name suggests, corn meal agar culture medium contains corn flour and is a suitable medium for identifying chlamydospore fungus by Candida albicans and also for maintaining and storing fungal culture, especially black pigment producing fungi.

• Oxytetracyline Glucose yeast agar

This culture medium is used to select and count molds and fungi in food. Oxytetracycline acts as a selective agent for further growth of yeasts and molds in neutral pH environments.

The method of growing mold and yeast on culture medium

• Homogenization of food and preparation of dilution
• Cultivation on a special culture medium (due to the aerobic nature of the cultivation on porplate is better)
• Incubation at 21-25 degrees for 5-7 days

Identification and counting of molds

It is possible to identify and count molds using the following 3 methods:

1. Staining with aniline blue or lactophenol blue and then observing it macroscopically
2. Culture slide test
3. Howard’s method