Aerobic filamentous fungi generally grow as long threads of various diameters. These threads can branch or remain as one single thread. Fungi do not bend at sharp angles, unless branching. Fungal hyphae are of uniform diameter along their entire length, although the branch may be of a slightly different diameter than the main length of the hypha. Fungal hyphae do not tear, fray, tatter, or disintegrate. If a material is doing any of these things, then it is not a fungal hypha. Fungi make some glue material, which they use to help bind themselves to surfaces. Bacteria, at least some species, typically make much more "glue slim layer" than fungi. Fungal hyphae can be clear or colorless (hyaline), tan, red, orange, gold, honey colored, lavender, brown, or black. In general, fungal species with some color to the hyphae tend to be more beneficial than species that have clear, or hyaline, hyphae. Diameters of hyphae also have a correlation with beneficial abilities.
1. Saphrophytic Fungi
The largest numbers off fungi are those that use non-living organic matter as their source of food. These are called Saprophytic fungi and include the beneficials that help suppress, compete with, and inhibit disease-causing organisms. In general, the wider the diameter of the hypha, the less likely it is to be a disease-causing fungal species. Of course, exceptions to this general rule occur, but if three or four species of wide-diameter, colored hyphae are present, it is almost sure proof that disease fungi will not be able to grow and cause damage to the desired plant. Fungi with diameters greater than 3.0 generally fall into the category of Basidiomycetes. Colored Basidiomycetes tend, for the most part, to be beneficial, whereas those species that are not colored, or have narrow diameters, include the few genera of disease-causing Basidiomycetes.
2. Mycorrhizal Fungi
Mycorrhizal fungi are a type of fungi that enter into a symbiotic relationship with plants. The term "mycorrhizae" means the structure built by the root-fungus association. The fungus solubilizes mineral nutrients from sand, silt, and clay, and from organic matter. It then transfers the nutrients to the plant in exchange for sugars the plant makes. In this way both orgnisms "win", by suriving and growing in places neither would manage without their symbiotic association. Mycorrhizal fungi are valuable because they colonize roots and prevent diseases (pathogenic fungi) from being able to establish on those roots.
Pathogenic fungi use living organic matter as a source of nutrients and cause the death of their host plant. They cause disease. These are not desirable in any growing system.
4. Fungal Aggregate (no 1)
Fungal aggregate --- note all the different types of fungi present in the picture --- but all are being attacked by a massive amount of bacteria indicative of anaerobic conditions.
Fungal Aggregate (no.1)
5. Fungal Aggregate (no 2)
A beautiful fungal aggregate demonstrating how the fungal aggregate incorporates many bacterial aggregates. this is how soil structure is built.
Fungal Aggregate (no. 2)