What is the difference between bacteria and fungi in the soil?

Soil is teaming with life of all kinds--from the roots of the biggest trees, to the smallest insects and mites, to microscopic creatures too small to see with the naked eye. These tiniest soil inhabitants are called micro-organisms, or just microbes for short. Diverse life forms fall into the microbe category, with the two most abundant in soil being fungi and bacteria. Scroll down for a table summarizing the differences between these two groups, or keep reading for a detailed description of each one!

You're probably familiar with fungi in the form of mushrooms. But in reality, mushrooms are just the tip of the iceberg so to speak. They are the fruiting bodies (spore- producing reproductive structures) of unseen fungal mycelia that weave vast networks of fine threads throughout the soil matrix. While the individual threads of fungus are microscopic, altogether they add up to staggeringly massive sizes--in fact, the largest single organism in the world is a fungal mycelium dubbed Oregon's "Humongous Fungus!" While some fungi can infect plants and cause disease, most of the time soil fungi are doing important work such as breaking down organic matter, strengthening soil structure by holding aggregates together, and partnering with plant roots to boost their nutrient uptake.

The word bacteria might conjure up the idea of germs and disease, but millions and billions of bacteria live on their own in every spoonful of soil without infecting a host organism. Similar to fungi, bacteria break down soil organic matter and release nutrients for uptake by plant roots. Most of these bacteria are single-celled organisms living on the surfaces of tiny soil particles, although some create networks similar to fungi (these are called filamentous bacteria). Click here to read about some specific examples of helpful bacteria living in your soil.

	Fungi	Bacteria
	Fungal mycelium growth on tree leaves. Image attribution: Rosser1954	Bacillus thuringiensis soil bacteria magnified 1000x. Image attribution: Dr. Sahay
Body shape?	Filamentous, long and stringy	Single cells, living in colonies/films
Mobility?	No, explores soil by growth	Yes, many can swim using flagella
Number of cells?	Up to trillions	One
Organization within cells?	Membranes section off organelles inside cells for different functions, e.g. nucleus for DNA (eukaryotic)	Cells are one unit with no organelles, no nucleus (prokaryote)
Cell wall composition?	Chitin: same tough material found in insect and crustacean shells	Peptidoglycan: keeps bacteria from bursting, since they have high internal pressure like an inflated tire
Reproduction?	Spore creation (individually or from two partners)	Cell division (cloning)
Partnership with plants?	Mycorrhizae: fungal fillaments penetrate plant roots Fungal hyphae growing over a plant root Image attribution: Topi Pigula	Legume nodules: specialized root growths nurture beneficial bateria Legume roots with nodules. Image attribution: Foxy Tigre

Fungi vs. bacteria in the soil: quick comparison chart! Note: these are general descriptions, but exceptions do exist.

At the end of the day, the biggest differences between fungi and bacteria come down to their cellular and molecular properties. In terms of the soil ecosystem, they overlap in many of the roles they play: recycling nutrients, breaking down organic matter, interacting with plant roots, and building soil structure. So if they seem similar, don't worry too much. They're all micro-organisms!