All living things can be classified into one of five fundamental Kingdoms of life, and the term fungus refers generically to all members of the Kingdom Fungi. There are more than a million species of fungi, but only about 400 cause diseases relevant to man, animals, or plants.

Fungus (singular) or Fungi (plural) are simple plants called "Saprophytes" that lack chlorophyll (the green coloring that plants use to make food). Because fungi lack chlorophyll, they cannot produce their own food. Therefore, they must take carbohydrates, proteins, and other nutrients from the animals, plants, or decaying matter on which they live.

They are any of a diverse group of eukaryotic single-celled or multinucleate organisms that live by decomposing and absorbing the organic material in which they grow, comprising the mushrooms, molds, mildews, smuts, rusts, and yeasts, and classified in the kingdom Fungi or, in some classification systems, in the division Fungi (Thallophyta) of the kingdom Plantae.

The majority of the pathogenic species are classified within the Phyla Zygomycota, Basidiomycota, Ascomycota, or the form group Fungi Imperfecti. Fungi (the singular form is 'fungus'), including those pathogenic to humans and animals, are eukaryotic microorganisms.

Classically, there are two broad groups of fungi: yeasts and moulds. While not mutually exclusive, mould spores germinate to produce the branching filaments known as hyphae. Yeasts, on the other hand, are solitary rounded forms that reproduce by making more rounded forms through such mechanisms as budding or fission.

Yeast reproduction occurs via budding (or fission) and the colonies are typically moist and mucoid.

Mould typically has interwoven filamentous forms known as hyphae. The mass of hyphae is called a mycelium. The hyphae grow by elongation at their tips. At the ends of some of these hyphae are rounded forms that could be confused with yeast, but that are instead called conidia or spores. These rounded fungal forms are relatively metabolically inactive. They can be likened to seeds--they are alive, but they're not doing much. Rather, they are looking for a good place to live.

Food Safety Implication: Some fungi, such as mushrooms, truffles, yeast, and the molds used to make some cheeses,  play a major role in a number of foods that we eat. However, other fungi can cause great damage and disease to animals and plants, including humans and sprouts.  Fungi can be microscopic or as big as a mushroom.

Where They Live: Fungi are found in the air, soil, plants, animals, water, and in some foods.

Types of Fungi Include:

  • Yeast - single-cell fungi; can cause skin infections;
  • Mushrooms - multi-cell fungi;
  • Molds and Mildew - multi-cell fungi; mold and mildew spores are allergens (substances that induce allergies);
  • Smuts - Disease-causing fungi of corn, wheat, and onion; and
  • Rusts - Disease-causing fungi of wheat, oats, beans, asparagus, snapdragon, and hollyhock.

Examples of fungus that attach sprouts include:

  • Macro¬≠phomina phaseoli (Charcoal rot)
  • Rhizopus stolonifera andRhizopus oryzae
  • Pythium