Live Bacteria & Fungi Specimens
Explore microscopic life that shapes ecosystems, health, and industry.
Overview
Bacteria and fungi are two major groups of organisms that play essential roles in nearly every environment on Earth. Bacteria are prokaryotic organisms and are among the most abundant forms of life, occurring in soil, water, and in close association with other living organisms. Fungi are eukaryotic organisms that obtain nutrients by digesting food externally and absorbing the resulting molecules into their cells. Together, bacteria and fungi are central to ecosystems, human health, and applied science.
Bacteria
Bacteria (singular: bacterium) are often used as a broad term for prokaryotes, but in this context the term is used specifically to refer to the eubacteria. Another major prokaryotic group is the Archaea, which are distinct from eubacteria. The study of bacteria is called bacteriology, a subfield of microbiology.
Bacteria are ubiquitous and can be found in nearly all habitats, including soil, water, and as symbionts of other organisms. Many bacterial species are beneficial, while some are pathogenic and cause disease. Most bacteria are extremely small, commonly measuring about 0.5–5.0 μm in length, though some “giant” bacteria can grow to sizes exceeding 0.5 mm.
Cell Structure and Movement
Many bacteria have cell walls, but bacterial walls are typically made of peptidoglycan, which differs from the cellulose found in plant cell walls and the chitin found in fungal cell walls. Some bacteria are motile and move using flagella, which are structurally distinct from the flagella found in eukaryotic organisms.
Fungi
Fungi are eukaryotic organisms that digest food externally and absorb nutrients into their cells. Although fungi were once classified as plants, they are not plants because they are heterotrophs and do not fix carbon through photosynthesis. Modern classification places fungi closer to animals than to plants, but fungi differ from animals in that they absorb food rather than ingest it. Fungi also typically have cell walls surrounding their cells, which is one reason they are placed in their own kingdom, Fungi.
Ecological and Human Importance
Fungi are primary decomposers in many ecosystems, breaking down dead plant and animal material and recycling nutrients. Humans use fungi in many important ways: yeasts enable fermentation in bread and beer, mushroom farming is a major industry, and fungi contribute to the production of medically valuable compounds. The biology of fungi is complex and extends far beyond their common appearance as molds on food.
Molds
Molds are various fungi that grow across surfaces as fluffy mycelia and often produce large quantities of spores, most commonly asexual spores but sometimes sexual spores. Mold growth commonly appears as a downy or furry coating on vegetable or animal matter and is often a sign of dampness or decay.
Molds are not a single taxonomic group and can occur across multiple fungal divisions, including Zygomycota, Deuteromycota, and Ascomycota. While mold is often associated with spoilage, some molds are intentionally cultivated, such as in the production of certain cheeses and in the development of antibiotics derived from fungal defense compounds.