Aflatoxin B1 Degradation by Stenotrophomonas Maltophilia and Other Microbes Selected Using Coumarin Medium

Abstract

Aflatoxin B 1 (AFB 1 ) is one of the most harmful mycotoxins in animal production and food industry. A safe, effective and environmentally sound detoxification method is needed for controlling this toxin. In this study, 65 samples were screened from various sources with vast microbial populations using a newly developed medium containing coumarin as the sole carbon source. Twenty five single-colony bacterial isolates showing AFB 1 reduction activity in a liquid culture medium were selected from the screen. Isolate 35-3, obtained from tapir feces and identified to be Stenotrophomonas maltophilia, reduced AFB 1 by 82.5% after incubation in the liquid medium at 37 °C for 72 h. The culture supernatant of isolate 35-3 was able to degrade AFB 1 effectively, whereas the viable cells and cell extracts were far less effective. Factors influencing AFB 1 degradation by the culture supernatant were investigated. Activity was reduced to 60.8% and 63.5% at 20 °C and 30 °C, respectively, from 78.7% at 37 °C. The highest degradation rate was 84.8% at pH 8 and the lowest was only 14.3% at pH 4.

Biocontrol efficacy ofLactobacillus fermentumYML014 against food spoilage moulds using the tomato puree model

“…Mycotoxin contamination is still a serious problem in many parts of the world (Richard and Payne 2003). This poses a threat to both livestock and human health, which results in great worldwide economic losses each year (Guan et al 2008). Diverse physical and chemical methods have been developed for controlling mycotoxin-contaminated food and feed, whereas very few of these techniques have been practically considered (Biernasiak et al 2006).…”

Fungal Detoxification of Certain Fusarium Moniliforme Mycotoxins Using Yarrowia Lipolytica with Special Emphasis on its Possible Mechanism of Action

“…The higher the temperature was, the faster the activity decreased. Similarly, Guan et al reported that when culture supernatant was heated (boiling water bath for 10 min), no mycotoxin degradation activity was observed [35]. After treatment with proteinase K and heat (Fig.…”

“…Moreover, the dead cells (autoclaved) exhibited the lowest detoxification activity against the two mycotoxins (Fig. 1) [35]. The extracellular extracts of Rhodococcus erythropolis liquid culture could degrade 66.8% aflatoxin B1 after 72 h incubation [36].…”

The role of Aspergillus oryzae KKB4 in reducing and detoxifying aflatoxin B1 applied in moist-heated corn

“…Sardjono et al (2004a) also supported that there were 5 protein fractions of extracellular enzyme produced by A. oryzae KKB4 in liquid synthetic medium. Moreover, the references have explained varied production and activity of AFB1 degrading enzymes, depending on type of substrate, moisture content, fermentation system, and environmental controlling (Guan et al, 2008;Hackbart et al, 2014). The AFB1 reduction is rarely correlated with the fungal biomass.…”