Detoxification of the Fumonisin Mycotoxins in Maize: An Enzymatic Approach

Abstract

Enzymatic detoxification has become a promising approach for control of mycotoxins postharvest in grains through modification of chemical structures determining their toxicity. In the present study fumonisin esterase FumD (EC 3.1.1.87) (FUMzyme®; BIOMIN, Tulln, Austria), hydrolysing fumonisin (FB) mycotoxins by de-esterification, was utilised to develop an enzymatic reduction method in a maize kernel enzyme incubation mixture. Efficacy of the FumD FB reduction method in “low” and “high” FB contaminated home-grown maize was compared by monitoring FB1 hydrolysis to the hydrolysed FB1 (HFB1) product utilising a validated LC-MS/MS analytical method. The method was further evaluated in terms of enzyme activity and treatment duration by assessing enzyme kinetic parameters and the relative distribution of HFB1 between maize kernels and the residual aqueous environment. FumD treatments resulted in significant reduction (≥80%) in “low” (≥1000 U/L, p < 0.05) and “high” (100 U/L, p < 0.05; ≥1000 U/L, p < 0.0001) FB contaminated maize after 1 h respectively, with an approximate 1:1 µmol conversion ratio of FB1 into the formation of HFB1. Enzyme kinetic parameters indicated that, depending on the activity of FumD utilised, a significantly (p < 0.05) higher FB1 conversion rate was noticed in “high” FB contaminated maize. The FumD FB reduction method in maize could find application in commercial maize-based practices as well as in communities utilising home-grown maize as a main dietary staple and known to be exposed above the tolerable daily intake levels.

Degradation of Aflatoxin B1 by a Sustainable Enzymatic Extract from Spent Mushroom Substrate of Pleurotus eryngii

“…Aqueous treatments with citric acid were used to reduce AFB1 in contaminated maize [45] as well as in extruded sorghum [46]. Scarpari et al [41] sprayed AFB1-contaminated maize with culture filtrates of T. versicolor containing Lac and obtained 50% degradation with 3.5 U and 70% degradation with 7.0 U of the enzyme in 48 h. Recently, a similar approach has been used for the enzymatic detoxifying of maize from fumonisin mycotoxins [47] and the technology has been proposed to be utilized as a safer alternative to water washing that is practiced in subsistence farming communities in Africa for the treatment of whole maize intended for human consumption. A major advantage of the proposed technology was that the bulk solution of the residual enzyme and the less toxic degradation products could be easily separated from the treated maize kernels.…”

Contamination of freshly harvested Bambara groundnut (Vigna subterranea) seed from Mpumalanga, South Africa, with mycotoxigenic fungi

“…Freshly harvested BGN seed samples as well as selected fungal cultures were screened for multiple toxins including deoxynivalenol (DON), nivalenol (NIV), zearalenone (ZEA), ochratoxin A, aflatoxin B 1 and fumonisin B 1 , B 2 , and B 3 using Ultra‐Performance‐Liquid‐Chromatography‐tandem mass spectrometry (UPLC‐MS/MS). The samples were analyzed by the Central Analytical Facility (CAF) at Stellenbosch University, South Africa) using their optimized standardized operating protocol that was validated as part of the Maize trust project (Project MTM 13/04) (J. Alberts et al, 2019). The pre‐cursor ion, product ion, cone voltage (V), and collision energy (eV) of each analyte is shown in Table 3 whereas Table 4 shows the established limit of detection [(LOD [ppb])] and limit of quantification [(LOQ [ppb])] for each analyte.…”

Sphinganine-Analog Mycotoxins (SAMs): Chemical Structures, Bioactivities, and Genetic Controls

“…welwitschiae have the ability to produce enzymes to synthesize non-aminated fumonisins that are less toxic than FB, and that those enzymes could be used for fumonisin detoxification [ 106 ]. Indeed, using enzymes to detoxify by modification of chemical structures has become a promising method for mycotoxins control after grains harvest [ 107 , 108 ]. For example, fumD (carboxylesterase) from Sphingopyxis catalyze detoxification of FB 1 to the hydrolyzed form by hydrolysis of both PTCA side chains.…”