Kinetics of deoxynivalenol degradation by Aspergillus oryzae and Rhizopus oryzae in submerged fermentation

Abstract

O objetivo foi avaliar a capacidade das espécies fúngicas Aspergillus oryzae e Rhizopus oryzae em degradar desoxinivalenol (DON) em fermentação submersa. O meio submerso utilizado foi água destilada estéril contaminada com 1mg mL -1 DON, inoculado com 4 × 10 6 esporos mL -1 das espécies fúngicas. A amostragem foi realizada a cada 48 h até 240 h de processo, determinando a massa residual de DON, percentual e velocidade de degradação. A massa residual de DON no meio coletado foi extraída por partição líquido-líquido e quantificada por cromatografia gasosa através de derivação com anidrido trifluoroacético. O tempo requerido para a maior degradação de DON foi 96 e 240 h para Aspergillus oryzae e Rhizopus oryzae, respectivamente, e velocidade de degradação de 0,62 e 0,54 mg h -1 , respectivamente. Rhizopus oryzae ocasionou a maior diminuição na concentração de DON, aproximadamente 90% em 240 h, enquanto Aspergillus oryzae ocasionou com maior rapidez, 74% de redução em 96 h.The objective was to evaluate the capacity of Aspergillus oryzae and Rhizopus oryzae to degrade deoxynivalenol (DON) during submerged fermentation. The submerged medium utilized was sterile distilled water with 1mg mL -1 DON, added and inoculated with 4 × 10 6 spores mL -1 of the fungal species. Sampling was performed every 48 h to 240 h. DON analyses included residual mass, percentage and velocity of degradation. Residual mass of DON in the collected medium was extracted by liquid-liquid partition and quantified by gas chromatography through derivation with trifluoroacetic anhydride. The time required for the largest DON degradation was 96 h and 240 h by Aspergillus oryzae and Rhizopus oryzae respectively, and degradation rate were 0.62 and 0.54 mg h -1 , respectively. Rhizopus oryzae caused the largest decrease in DON at around 90% in 240 h, while Aspergillus oryzae caused the most rapid degradation with a 74% reduction of DON at 96 h.

Transcriptomic profiling to identify genes involved in Fusarium mycotoxin Deoxynivalenol and Zearalenone tolerance in the mycoparasitic fungus Clonostachys rosea

“…A recent finding reported an ability to degrade ZEA in the bacterium Rhodococcus pyridinivorans , although the detoxification mechanism of the strain is not yet known [ 15 ]. On the other hand, peroxidase was speculated to degrade DON in A. oryzae and Rhizopus oryzae [ 16 ] whereas hydrolytic breakdown of DON was found in A. tubingensis [ 17 ]. Several bacteria have also been found to be capable of detoxifying DON.…”

Commercial and Noncommercial Peroxidases Activity under Ultrasound and Microwave Treatment: a Pretreatment to Improve Wastewater Treatment

“…One unit of peroxidase activity was defined as the protein mass that can cause an increase of 0.001 in absorbance unit per minute. 14 …”

Removal of a red dye using noncommercial peroxidase extracted from rice bran

“…The enzymatic activity was estimated through the oxidation reaction of the substrate to tetraguaiacol characterized by the orange color. One unit of peroxidase activity was defined as the protein mass that can cause an increase of 0.001 in absorbance unit per minute (Devaiah & Shetty, 2009;Garda-Buffon & Badiale-Furlong, 2010).…”