Mold is a ubiquitous problem than impacts homes, businesses, churches, schools, and a multitude of other types of buildings in Southern California and around the world. Because of the widespread nature of mold, any person confronted with the prospect of having to deal with mold needs to have a basic understanding of mold. This includes having an appreciation of the basic biology of mold.

Basic Scientific Definition of Mold

The technical or scientific definition of mold is a fungus that grows in the form of multicellular filaments called hyphae. This will all be explored in greater detail throughout this article.

Species of Mold

There are thousands of different types of mold on Earth today, including in Southern California and across the United States. The most common genera of mold found in California and elsewhere in the United States (and much of the world) are:

  • Acremonium
  • Alternaria
  • Aspergillus
  • Cladosporium
  • Fusarium
  • Mucor
  • Penicillium
  • Rhizopus
  • Stachybotrys
  • Trichoderma
  • Trichophyton

Mold Spores

Mold grows from what are known as spores. These spores are extremely small and cannot be seen with the naked eye. They are notably smaller than the circumference of a human hair.

Mold spores are just about everywhere. They are all around out of doors. They are in your home. They are in your business. Everywhere.

Most mold spores are designed to be dispersed near and far in the air. There are some types of mold spores that are designed to be dispersed via water. Mold spores can cling to animal fur for transmission. They can cling to your clothing for dispersal as well.

Mold spores are structured in a manner that they are capable of surviving unscathed in extreme weather conditions. They are also capable of remaining viable for extended periods of time.

As is discussed in a moment, mold spores germinate easily if a set of specific conditions are met. At the heart of these conditions are moisture and biological matter.

Mold Colonies

Mold grows in what fairly can be called colonies. Indeed, by the time mold is visible to the naked eye, a particular mold colony is large.

A mold colony does not consist of single, discrete organisms. Rather, a mold colony is an interconnected network of what scientifically are known as hyphae. Hyphae are hair-like strands of mold. Nutrients are absorbed through the tip of a specific hyphae “strand.”

Mold and Organic Matter

Mold needs nourishment. Mold obtains that nourishment by growing on organic matter.

Mold requires only a small amount of organic matter to live. Mold ingests that organic matter very slowly.

An example of mold utilizing organic matter for its nourishment is found on food items that “have gone bad.” You may see a small amount of mold initially. Over time, the mold on a food item increases. A considerable amount of time can pass before the mold completely “ingests” a particular food item.

Mold and Temperature

Generally speaking, mold requires a warmer temperature to grow. Provided moisture is present (a temperature above freezing) the prospect for mold germination is there. The typical temperature of a residential property or a business is suitable to mold spore germination and mold growth.

A cooler temperature will slow mold growth in some cases. However, that alone will not stop mold growth.

Mold and Moisture

The most important factor to understand about mold growth is moisture. A mold spore needs moisture to germinate. Mold needs moisture to grow and thrive.

Although moisture is necessary for mold to grow, only a minimal amount of water or liquid is necessary for mold to bloom and thrive. Indeed, the amount of moisture needed for mold to live can be as minimal as condensation on a surface.

Common sources of moisture that results in mold growth in a home include:

  • Leaky pipes
  • Leaky faucets
  • Leaky plumbing fixtures
  • Condensation
  • Water seepage in flooring, walls, ceiling, roof
  • Moisture accumulating from showering and other water usage

Mold and Food Production

When it comes to fully understanding the biology of mold, you need to appreciate how mold is used in food production. Types of mold that are used in food production included:

  • Fusarium venenatum 
  • Geotrichum candidum 
  • Neurospora sitophila 
  • Penicillium 
  • Rhizomucor miehei
  • Rhizopus oligosporus 
  • Rhizopus oryzae 

Mold and Pharmaceuticals

Mold is also used in the production of certain types of pharmaceutical products. The best known of these is Penicillium rubens from which penicillin is manufactured.

Health Effects of Mold

Research is ongoing and not yet concluded when it comes to the health effects of mold on humans. With that said, there is some basic information that is well-settled in regard to the health impact of mold on people.

Examples of more minor health issues associated with mold exposure include:

  • Sneezing
  • Runny or stuffy nose
  • Cough and postnasal drip
  • Itchy eyes, nose and throat
  • Watery eyes
  • Dry, scaly skin

There are some more significant health conditions associated with exposure to mold. This is the area in which research is still ongoing and much still remains to be learned. Nevertheless, examples of some of the more significant health issues associated with mold exposure include:

  • Inflammatory ailments
  • Toxic responses to mold spores
  • Respiratory symptoms of different types
  • Allergic alveolitis
  • Chronic rhinosinusitis
  • Fungal sinusitis
  • Hypersensitivity pneumonitis
  • Production of mycotoxins