Characterisation and determination of metabolites formed by microbial and enzymatic degradation of ergot alkaloids

Abstract

Ergot alkaloids are frequent contaminants of cereal crops. Strategies for their inactivation include the use of microorganisms or enzymes as feed additives capable of degrading ergot alkaloids. Recently, an ergopeptine-degrading Rhodococcus erythropolis strain MTHt3 (DSM 25948) has been isolated from soil and the involved enzymes ErgA and ErgB have been identified. The aim of the current study was to characterise the metabolites formed by degradation of various ergopeptines with the MTHt3 strain, its lysate and the purified enzyme ErgA. Using preparative HPLC, 1H-, 13C- and 2D-NMR as well as HR-MS measurements, two main groups of metabolites formed during microbial and enzymatic degradation of ergopeptines were identified: diketopiperazines (cyclic dipeptides, DKPs) and unstable ergine hydroxy carboxylic acids. However, degradation by strain, lysate and enzyme yielded different end-products. Whereas DKPs were transient and lysergic acid the only final product upon incubation of ergopeptines with the R. erythropolis strain, incubation with the lysate resulted in formation of lysergic acid and two isomeric DKPs at different ratios. Enzymatic degradation by ErgA yielded only one DKP isomer and ended at the stage of the ergine hydroxy carboxylic acids which then spontaneously degraded to ergine. In conclusion, we succeeded in identification of metabolites formed by microbial and enzymatic degradation of ergot alkaloids which is a crucial step in the future development of feed additives for gastro intestinal detoxification of ergopeptines in farm animals.

Ergot Alkaloids Mycotoxins in Cereals and Cereal-Derived Food Products: Characteristics, Toxicity, Prevalence, and Control Strategies

“…Yeast, bacteria, fungi, and enzymes have been used as biocontrol agents in order to cause degradation or absorption of many mycotoxins [103][104][105][106]. Transformation, adsorption, degradation, or adsorption are some of the mechanisms by which agricultural products of plant or animal origin as well as animal feed can be detoxified from mycotoxins [103].…”

Enzymes for Detoxification of Various Mycotoxins: Origins and Mechanisms of Catalytic Action

“…Aflatoxin dialdehyde aldo-keto reductase AKR7A1 (Figure 2 [15,16], Table 1 [17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58]) was isolated from rat liver, and its structure in complex with NADP + was solved [59]. This enzyme is assumed to reduce both aldehyde groups of dialdehyde of hydroxy aflatoxin B 2a , forming from 8,9-dihydrodiol aflatoxin B 1 , resulted in dihydroxy derivative.…”

“…Multiple ergot alkaloids are degraded by ErgA from bacteria Rhodococcus erythropolis (Figure 10) [49]. Particularly, the products of ergotamine ((6a R ,9 R )- N -[(1 S ,2 S ,4 R ,7 S )-7-benzyl-2-hydroxy- 4-methyl-5,8-dioxo-3-oxa-6,9-diazatricyclo[7.3.0.02,6]dodecan-4-yl]-7-methyl-6,6a,8,9-tetrahydro-4 H -indolo[4,3-fg]quinoline-9-carboxamide) degradation are following: cyclic dipeptide R -Pro- S -Phe and assumed unstable hemiaminal intermediate, ergine pyruvate.…”

Degradation of Aflatoxins by Means of Laccases from Trametes versicolor: An In Silico Insight

“…The main advantage of using enzyme-based strategies is the possibility to act at the different stages of food and feed production chains. Indeed, enzymes are currently considered as food/feed additives or agents during the from-field-to-fork pathway, and they are aimed at reducing the carryover and accumulation in the final products [ 30 ]. Nonetheless, while the safety and security of genetically modified organisms for health and environment are under a heated scientific debate, the genome engineering by introducing effective enzymes in susceptible hosts or detoxifying microorganisms can be thought as a possible (future) strategy (e.g., ref.…”