Production of volatile compounds by the edible fungus Rhizopus oryzae during solid state cultivation on tropical agro-industrial substrates

When Rhizopus oryzae was grown on medium containing cassava bagasse plus soybean meal (5:5 w/w), CO2 production was at its highest (200 ml.l(-1)) while highest volatile metabolite production was with amaranth grain as substrate (282.8 ml.l(-1)). In the headspace, ethanol was the most abundant compound (more than 80%). Acetaldehyde, 1-propanol, ethyl propionate and 3-methyl butanol were also present. CO2 and volatile metabolite productions reached their maxima around 20 h and 36 h, respectively.