Zygomycetes-based biorefinery: present status and future prospects

Fungi of the phylum Zygomycetes fulfil all requirements for being utilized as core catalysts in biorefineries, and would be useful in creating new sustainable products. Apart from the extended use of Zygomycetes in preparing fermented foods, industrial metabolites such as lactic acid, fumaric acid, and ethanol are produced from a vast array of feedstocks with the aid of Zygomycetes. These fungi produce enzymes that facilitate their assimilation of various complex substrates, e.g., starch, cellulose, phytic acid, and proteins, which is relevant from an industrial point of view. The enzymes produced are capable of catalyzing various reactions involved in biodiesel production, preparation of corticosteroid drugs, etc. Biomass produced with the aid of Zygomycetes consists of proteins with superior amino acid composition, but also lipids and chitosan. The biomass is presently being tested for animal feed purposes, such as fish feed, as well as for lipid extraction and chitosan production. Complete or partial employment of Zygomycetes in biorefining procedures is consequently attractive, and is expected to be implemented within a near future.

Safety evaluation of Mucor rouxii CFR-G15 biomass containing ω-6 fatty acids in rats

Mucor rouxii CFR-G15 is an oleaginous zygomycetous fungus. The mycelia of the fungus accumulate 35.0±0.8% total lipid of which, 18.55±0.46% is gamma linolenic acid. Acute and subchronic studies were conducted by feeding rats with dry biomass of M. rouxii CFR-G15 to assess the safety of the oils in the fungal mycelium. For acute toxicity studies, adult male rats fed with diet at 0, 5000, 10,000, 25,000, 50,000 mg/kg bw for 1 day, and the animals were monitored for 14 days. Rats weighing 35±2.5 g were fed for 13 weeks with a diet incorporating 2500, 5000, 10,000 and 20,000 mg/kg (w/w) dry biomass for subchronic toxicity studies. Control consists of the diet without the dry biomass. Dietary feeding of M. rouxii biomass at any level showed no significant changes (p>0.05) in food intake, body weight, organs weight and serum enzymes. Macroscopic and microscopic observations revealed that the vital organs were unaffected by the feed containing the dry biomass. However, triglycerides and cholesterol levels in serum were decreased significantly (p<0.05) in the test rats. The results of this study suggests that feeding fungal mycelia containing oil is safe when fed to rats and also shows positive effects on controlling triglycerides and cholesterol.