mold

Table of Contents

Introduction References & Edit History

Images & Videos

Observe time-lapse photography of Penicillium mold releasing penicillin to its surroundings

Learn how mold inspectors protect clients while removing the dangerous fungus from their homes

Read Next

Hand washing. Healthcare worker washing hands in hospital sink under running water. contagious diseases wash hands, handwashing hygiene, virus, human health

17 Questions About Health and Wellness Answered

A potato showing the effects of Phytophthora infestans, or late blight. Potato blight, Irish Potato Famine.

The Mold that Wrecked Ireland

Discover

When Does Summer Start?

Planet Jupiter with its moon Io at left, photographed by the Cassini orbiter during the Cassini-Huygens mission, 2000. spacecraft

7 Important Dates in Jupiter History

A mug shot taken by the regional Colombia control agency in Medellin

Pablo Escobar: 8 Interesting Facts About the King of Cocaine

An ancient egyptian hieroglyphic painted carving showing the falcon headed god Horus seated on a throne and holding a golden fly whisk. Before him are the Pharoah Seti and the goddess Isis. Interior wall of the temple to Osiris at Abydos, Egypt.

11 Egyptian Gods and Goddesses

Poker game. Card game. Royal Flush in poker. Hearts suit gambling

Poker Hands Ranked

Queen Elizabeth II addresses at opening of Parliament. (Date unknown on photo, but may be 1958, the first time the opening of Parliament was filmed.)

All 119 References in “We Didn’t Start the Fire,” Explained

Johanna Sigurdardottir Iceland's first female prime minister, the first openly gay prime minister in the world. A Veteran M (longest serving MP) elected in 1978 for the Social Democratic party. Official photo 2009

7 People Who Shaped LGBTQIA+ World History

mold

fungus

Also known as: mould

Written and fact-checked by The Editors of Encyclopaedia Britannica

Last Updated: May 24, 2025 • Article History

Also spelled:: mould

Key People:: George Wells Beadle; Edward L. Tatum

Related Topics:: Rhizopus; Aspergillus; Penicillium; Fusarium; Neurospora

On the Web:: National Center for Biotechnology Information - PubMed Central - Mold, Mycotoxins and a Dysregulated Immune System: A Combination of Concern? (May 10, 2025)

News •

When fungi take your breath away—how a mold can unbalance the lungs • May 21, 2025, 9:53 AM ET (Medical Xpress)

peach moldMagnified view of peach mold (*Rhizopus*).

mold, in biology, a conspicuous mass of mycelium (masses of vegetative filaments, or hyphae) and fruiting structures produced by various fungi (kingdom Fungi). Fungi of the genera Aspergillus, Penicillium, and Rhizopus form mold and are associated with food spoilage and plant diseases.

This article was most recently revised and updated by Kara Rogers.