Mucoromycota represents a phylum within the kingdom of Fungi. This group includes molds like Mucor and Rhizopus. They are widespread, found in many environments globally, playing beneficial ecological roles and impacting health.
Understanding Mucoromycota
Mucoromycota are characterized by rapid growth and generally aseptate hyphae, meaning they lack internal cross-walls. When septa do occur, they typically form at the base of reproductive structures. This phylum encompasses subphyla such as Mucoromycotina, Mortierellomycotina, and Glomeromycotina.
They are ubiquitous, inhabiting soil, decaying organic matter, and plant surfaces. Some species are also found in indoor environments. Their ability to quickly colonize carbon-rich substrates makes them early inhabitants of decaying materials.
Ecological Contributions
Mucoromycota play roles in ecosystems, primarily as saprophytes. They break down complex organic matter like dead plants and animals. This decomposition releases nutrients back into the soil, making them available for plants and other organisms, contributing to nutrient cycling.
Some Mucoromycota also form symbiotic relationships with plants. Mycorrhizal fungi, a type of Mucoromycota, enhance a plant’s ability to absorb nutrients like phosphorus and nitrogen from the soil. In exchange, plants provide the fungi with carbohydrates produced through photosynthesis. These associations contribute to soil health and fertility, and can even increase crop yields.
Impact on Human and Animal Health
Some Mucoromycota species can be opportunistic pathogens, affecting animals and humans with compromised immune systems. The main health implication is mucormycosis, a severe fungal infection caused by Mucorales molds. This infection is rare but can progress rapidly.
Risk factors include uncontrolled diabetes (especially with high blood sugar or ketoacidosis) and conditions that weaken the immune system, such as cancer, organ transplants, and prolonged corticosteroid use. Individuals with hemochromatosis (too much iron) also face increased risk. Infection typically occurs when spores from environmental mucormycetes are inhaled or enter the body through cuts, burns, or surgical wounds.
Symptoms of mucormycosis vary depending on the affected body part.
- Rhino-orbital-cerebral mucormycosis, the most common type, affects the sinuses, eyes, and brain, causing facial pain, nasal congestion, headaches, swelling around the eyes, and potentially vision loss or black lesions on the nasal bridge.
- Pulmonary mucormycosis affects the lungs, presenting with fever, cough, chest pain, and shortness of breath.
- Cutaneous mucormycosis occurs when fungi enter through broken skin, causing painful blisters, ulcers, or discolored patches.
- Gastrointestinal mucormycosis, less common, is seen more often in premature infants or those with malnutrition, causing abdominal pain and nausea.
Early diagnosis and aggressive treatment, typically involving antifungal medications like amphotericin B and surgical removal of infected tissue, are important due to the high fatality rate (around 54%).
Beneficial Applications
Beyond ecological roles, some Mucoromycota have beneficial applications, especially in food production. Rhizopus species are used in the traditional fermentation of soybeans to produce tempeh. Tempeh is an Indonesian food rich in protein and fiber, with improved nutritional value due to fermentation.
Rhizopus oligosporus is the primary starter culture for tempeh, forming a white mycelial mass that binds soybeans. This fermentation enhances the bioavailability of compounds and can reduce antinutritional factors in soybeans. Some Mucor species may also contribute to the flavor and texture of fermented products.