Thursday, July 9, 2015

09/07/2015: Research gathers pace to combat mycotoxins in aquaculture - Turkeys, trout and 1960

by Dieter Moll, Research Team Leader Molecular Biology, BIOMIN

First published in International Aquafeed, May-June 2015

The year 1960 is commonly regarded as the starting point that led to the discovery and study of mycotoxins. While many in the mycotoxin research community are familiar with the turkey 'X' disease that year when turkeys in England died from aflatoxin contamination, few know about the epizootic of hepatoma in trout occurred in California that same year, later found to be caused by aflatoxins.

At the BIOMIN Research Center, we take advantage of the fact that mycotoxins are natural molecules.

Mycotoxins are degradable in the environment, and a goal of our research is to get natural mycotoxin degradation and detoxification reactions to work in the gastrointestinal tract of animals.

Our molecular biology team has isolated strains of fumonisin-degrading bacteria, and studied the molecular biology and biochemistry of fumonisin degradation in detail. We found that a cluster of genes has been shaped and optimised by evolution over countless years specifically to break down fumonisins and use them for bacterial cellular metabolism.

Transcription of the genes is turned on in the presence, and turned off in the absence of fumonisins, and availability of fumonisins accelerates bacterial growth.

One particular enzyme of the degradation pathway, fumonisin esterase, is now available and registered in the EU as the world’s first mycotoxin degrading feed enzyme, FUMzyme®.

Fumonisin esterase removes two side chains from fumonisins by hydrolytic cleavage.

This cleavage drastically reduces the affinity of the mycotoxin to the eukaryotic target protein, ceramide synthase. An important part of developing FUMzyme® for use as feed enzyme for gastrointestinal fumonisin detoxification was to develop biomarkers of fumonisin exposure and fumonisin effects.

We established sophisticated methods, based on liquid chromatography and mass spectrometry, to measure concentrations of fumonisin-derived metabolites, and metabolites involved in ceramide synthase activity in samples from animals.

These methods allow to study dose and effect of fumonisins and of FUMzyme®, and were already used to tune FUMzyme® formulation and dose for pigs and poultry. Aquatic species should be next, and we already know that fumonisin esterase activity at low temperature is still very high.

We have also made microbes for detoxification of zearalenone and deoxynivalenol available as feed additives. Most recently, we isolated a bacterial strain which breaks down ergopeptines, the predominant class of ergot alkaloids.

Aquatic species are sensitive to mycotoxins, and aquaculture is young and open to science and innovation. For these reasons, application of mycotoxin detoxification biotechnology in aquaculture is a particularly interesting challenge for us at Biomin.

Read the magazine HERE.

The Aquaculturists
This blog is maintained by The Aquaculturists staff and is supported by the
magazine International Aquafeed which is published by
Perendale Publishers Ltd

For additional daily news from aquaculture around the world: aquaculture-news

No comments:

Post a Comment