Light micrograph of hyphae from a Rhizopus oryzae fungus. This fungus is found in soil and decaying organic matter and is used in the production of fermented foods. It can cause the rare but serious disease mucormycosis (zygomycosis) in patients that are immunocompromised or undergoing steroid therapy. The fungus can infect the lungs, sinuses, brain, gastrointestinal system, or the skin. In 2021 outbreaks of mucormycosis were seen in diabetic patients with Covid-19. Treatment is with antifungal drugs, although surgery is often needed to cut away the infected tissue.