Avaliação da produção de micotoxinas e estudo da biomassa de Penicillium sclerotiorum em meios de cultura com diferentes concentrações de nutrientes

Abstract

Penicillium sclerotiorum is a species of filamentous fungus which produces biomass with high moisture, protein and mineral contents and low content of lipids. Therefore, it has been the subject of studies aimed at its use in food industry. The present work investigated if there is mycotoxin production by P. sclerotiorum (which would limit its use in food industry), as well as the influence of changes in cultivation environment over metabolic profile of this fungus and nutritional composition of its biomass. There were carried out two sets of experiments, with culture media using variable amounts of glucose, peptone and sodium chloride and fixed amounts of potassium phosphate and magnesium sulfate. Differences were observed in the color of the biomass and fermented culturing media as well as in the chromatographic profiles, between the different culture media used, indicating that there was modulation of fungal metabolism according to changes in growing conditions. There were not detected ochratoxins A and B, cyclopiazonic and penicillic acids, citrinin and patulin in the fungal extracts analyzed. Sclerotiorin production ranged between 0.010 mg/mL and 0.152 mg/mL in the first cultivation and 0.202 mg/mL and 0.699 mg/mL in the second cultivation (no significant difference in the last case). Biomass yields ranged between 1.89 g and 7.80 g, being greater in culture media with the highest amount of glucose. Moisture levels ranged from 37.48% and 80.88%. Ash levels ranged from 3.55% to 18.11%, based on dry weight (d.w.). Macro and micronutrient levels ranged from 11.9 mg/100 g to 137.5 mg/100 g for Ca, 87.2 mg/100 g to 154.2 mg/100 g for Mg, 0.9 mg/100 g to 3.0 mg/100 g for Zn (no significant difference), 0.6 mg/100 g to 1.7 mg/100 g for Fe (no significant difference), based on d.w. Protein levels ranged from 21.56% to 41.88% based on d.w. Fatty acid profiles revealed the presence of the essential fatty acids linoleic and linolenic, the first one being detected in greater quantities in all samples analyzed. The results indicate that P. sclerotiorum is able to be used in the production of a nutritious and safe biomass for food industry.