Humus forming fungi includes which genera

Humus is the dark organic matter in soil that is formed by the decomposition of plant and animal matter by the act of micro-organisms i.e. bacteria and fungi. It is rich in nutrients and retains moisture in the soil.
Organic matter is humified by a combination of saprotrophic fungi, like Alternaria and Aspergillus. Whereas Trichoderma strains are used for biological control of plant disease.