Difference Between Mold And Yeast (With Pictures)


Learn the primary differences between Mold and Yeast. The basis of comparison include: Definition reproduction, appearance and texture, examples, growth conditions, number of species, habitat, virulence, conversion of food substances, uses, cell structure, hyphae and health problems.

What is Mold?

Mold refers to a type of multicellular fungus that grows in the form of multicellular filaments called hyphae. Mold is a natural part of the environment. They break down organic matter, such as dead leaves, wood, and other decaying materials.

Molds reproduce by producing tiny spores that are dispersed through the air. When these spores land on a suitable surface with moisture and nutrients, they can germinate and grow into new mold colonies. Some molds can produce allergens, irritants, and even toxic substances known as mycotoxins, which can cause respiratory problems, allergic reactions, and other health issues in susceptible individuals.

Key characteristics of mold

  • Mold consists of multiple cells organized into filaments called hyphae. These hyphae can intertwine to form a tangled network known as mycelium.
  • Mold reproduces by producing spores, which are small reproductive structures. These spores are lightweight and can easily become airborne, allowing mold to spread and colonize new areas.
  • Mold thrives in moist and warm environments. It can grow on a variety of surfaces, including food, wood, paper, and fabric.
  • Mold colonies can appear in colors, including black, green, blue, and white. The texture of mold can be fuzzy or slimy, depending on the species and environmental conditions.

What is Yeast?

Yeast is a type of single-celled fungus belonging to the kingdom Fungi. Unlike mold, which typically forms multicellular structures, yeast exists as individual cells. Yeasts are largely distributed in nature and can be found in habitats such as soil, water, and the surfaces of plants and animals.

The most well-known and extensively studied yeasts is Saccharomyces cerevisiae, commonly known as baker’s yeast or brewer’s yeast. This species of yeast is particularly significant because of its importance in the production of fermented foods and beverages, such as bread, beer, and wine.

Characteristics of yeast

  • Yeast cells are unicellular, meaning they consist of a single cell. These cells are spherical or oval in shape.
  • Yeast reproduces asexually by budding, where a smaller daughter cell forms on the surface of the parent cell and eventually detaches to become a new individual.
  • Yeast has the ability to metabolize sugars anaerobically, converting them into alcohol and carbon dioxide. This process, known as fermentation, is utilized in the production of alcoholic beverages and leavened bread.
  • Yeasts are versatile organisms that can thrive in various environments, including soil, water, and the bodies of plants and animals. Some species of yeast are also used as model organisms in scientific research.

Also Read: Difference Between Protista, Monera And Fungi

Differences Between Molds and Yeast In Tabular Form

Points of Comparison Mold Yeast
Definition Mold is a type of fungus that contains multiple identical nuclei. It grows in multi-cellular filaments known as hyphae. Yeast is a type of microscopic fungus that contains only a single oval cell.  
Reproduction Reproduce both sexually and asexually using spores. Reproduce asexually through binary fission (budding).  
Appearance and Texture Have a thread-like appearance and can be seen in wide variety of colors and hues with a wooly or fuzzy texture. Are oval in shape and is colorless and smooth.  
Examples Examples of mold include: Alternaria, Aspergillus,  Fusarium, Mucor, Penicillium, Rhizopus, Trichophyton etc. Examples of yeast include: Saccharomyces cerevisiae,  Cryptococcus neoformans etc.  
Conditions For Growth Molds can grow in a wide range of acidity PH levels. Yeast can grow in limited range of acidity (PH) of between  4.0 to 4.5.
Number of Species There are about 1000 known species of molds. There are about 1500 known species of yeast.  
Habitat Molds typically grow in damp, dark or steam-filled areas. Yeast can be found on fruits and berries, in the stomach of mammals and on skin and many other places.
Virulence Molds are more virulent (much harmless) when compared with yeast.   Yeasts are less virulent (less harmless) when compared with molds.  
Conversion of Food Substances Molds secrete hydrolytic enzymes to external food sources and convert them into simple substances that can be absorbed. Yeast converts carbohydrates to alcohol during fermentation.  
Uses Used in making cheese, rannit, vitamin supplements and antibiotics such as penicillin. It is also used in biodegradation and study of cell cycle. Used in making alcoholic beverages which contain ethanol, used in baking, ethanol production, production of food additives and flavors.  
Cell Structure Multi-cellular with tubular and filamentous hyphae. Uni-cellular and exists either individually or with buds growing on them.  
Hyphae Molds have microscopic filaments known as hyphae.   Yeast do not have true hyphae, they form multi-cellular structures known as pseudo-hyphae.
Health Problems Molds cause allergic reactions and respiratory inflammations. Yeast can cause infections in individuals with weak immune systems.  

 What are the Similarities Between Yeast and Mold?

  • Both yeast and mold are types of fungi.
  • Both yeast and mold have a chitin, a glucose derivative (chitin is the one substance that unifies all fungi including yeast, molds, rusts and mushrooms.
  • Yeast and mold are saprophytes.
  • Both yeast and molds can decompose porous household surfaces like wood and plaster.
  • Both yeast and molds undergo chemical reactions during their germination processes (they cause foods to deteriorate or decompose.
  • Both yeast and mold require moisture for germination.
  • Both yeast and mold are vulnerable to heat. Heat can eliminate moisture and neutralize fungal spores.
  • Both yeast and mold require oxygen to grow properly. Molds cannot grow without oxygen while yeast suffers stunted growth in an oxygen-derived environment.
  •  Both molds and yeast grow by multiplying their spores and therefore do not need light at all to grow properly, the way others the way other plants require light in order grow properly.
  • Molds and yeast are both capable of causing allergic reactions. They both come from airborne spores; they can pollute the airwaves of an allergic person and cause symptoms.
  • Some types of molds and yeasts can even cause severe infections.
  • Both mold and yeast are eukaryotes and share a similar cell structure.

Also Read: Difference Between Unicellular And Multicellular Organisms