ABSTRACT
Aims@#Deoxynivalenol is a type B trichothecene produced by Fusarium graminearum that can cause serious health problems in human and livestock. The present study aimed to reduce and detoxify deoxynivalenol using a local strain Aspergillus oryzae KKB4 and Rhizopus oryzae KP1R1. @*Methodology and results@#Corn as solid substrate artificially inoculated with F. graminearum bio 163252 to produce deoxynivalenol. Deoxynivalenol contaminated corn then inoculated with A. oryzae KKB4 and R. oryzae KP1R1. During fermentation, a decrease in deoxynivalenol levels is analyzed including loss of dry matter and glucosamine content. Deoxynivalenol was extracted from the substrate by solid phase extraction and quantified using high-performance liquid chromatography. The reduction of deoxynivalenol by A. oryzae KKB4 and R. oryzae KP1R1 were 65.91% and 56.82%, respectively after ten days of fermentation. Toxicity analysis revealed that residues of deoxynivalenol were not toxic to growth of Saccharomyces cerevisiae cells. @*Conclusion, significance and impact of study@#Local strains A. oryzae KKB4 and R. oryzae KP1R1 were able to reduce and detoxify deoxynivalenol in solid substrates. This study provides supporting data to control mycotoxin that is critical for food and feed safety.
ABSTRACT
Aims: The growth and metabolic activity of Aspergillus oryzae KKB4 in AFB1-contaminated corn and later coincided with AFB1 reduction and detoxification were investigated. Methodology and results: The decreasing of AFB1 amount by A. oryzae KKB4 could be clearly observed if the initial AFB1 concentration in corn was increased. Thus, moist-heated corn was artificially inoculated with Aspergillus flavus FNCC 62C7 to increase AFB1 content. AFB1-contaminated corn was applied as solid substrate and then inoculated with A. oryzae KKB4. During fermentation periods, the growth, metabolic activity, and AFB1 decline were investigated by glucosamine content, water content loss, and AFB1 concentration, respectively. The maximum growth was occurred in 4 thday at 1.499 ± 0.028 g glucosamine/ 100 g dry matter. The metabolic activity was going on up to the end of fermentation days, as shown as water content loss at 0.175 ± 0.007 g/g dry matter. In accordance with the growth and metabolic activity, the amount of AFB1 reduction was 37.04 ng AFB1/g dry matter during 5 days fermentation. According to toxicity analysis, it was found that the residues of AFB1 were not toxic to Bacillus megaterium cells. Conclusion, significance and impact of study: A. oryzae KKB4 is able to be applied in solid substrates as AFB1 reduction and detoxification agent. These lucrative effects are also important in relation with food and feed safety.