Fumonisins in Conventional and Transgenic, Insect-Resistant Maize Intended for Fuel Ethanol Production: Implications for Fermentation Efficiency and DDGS Co-Product Quality

Abstract

Mycotoxins in maize grain intended for ethanol production are enriched in co-product dried distiller’s grains and solubles (DDGS) and may be detrimental to yeast in fermentation. This study was conducted to examine the magnitude of fumonisin enrichment in DDGS and to analyze the impacts of insect injury, Fusarium ear rot severity, and fumonisin contamination on final ethanol yield. Samples of naturally-contaminated grain (0 to 35 mg/kg fumonisins) from field trials conducted in 2008–2011 were fermented and DDGS collected and analyzed for fumonisin content. Ethanol yield (determined gravimetrically) was unaffected by fumonisins in the range occurring in this study, and was not correlated with insect injury or Fusarium ear rot severity. Ethanol production was unaffected in fumonisin B1-spiked grain with concentrations from 0 to 37 mg/kg. Bacillus thuringiensis (Bt) maize often has reduced fumonisins due to its protection from insect injury and subsequent fungal infection. DDGS derived from Bt and non-Bt maize averaged 2.04 mg/kg and 8.25 mg/kg fumonisins, respectively. Fumonisins were enriched by 3.0× for 50 out of 57 hybrid × insect infestation treatment combinations; those seven that differed were <3.0 (1.56 to 2.56×). This study supports the industry assumption of three-fold fumonisin enrichment in DDGS, with measurements traceable to individual samples. Under significant insect pest pressures, DDGS derived from Bt maize hybrids were consistently lower in fumonisins than DDGS derived from non-Bt hybrids.

Global Mycotoxin Occurrence in Feed: A Ten-Year Survey

“…Although the global datasets of maize and maize DDGS samples analyzed in this study are not directly comparable, as they contain samples from varying geographical regions over a 10-year period, and consequently the maize samples analyzed may not resemble the maize used as starting material for DDGS production, our results confirm higher mycotoxin concentrations in maize DDGS compared to maize grains. The notable exception in our data is for fumonisins, which are known in the literature to concentrate in DDGS at levels around three times the original grain levels [20]. The opposite pattern in our results is likely to be largely related to high sample numbers of corn grain and lack of DDGS from high-fumonisin regions of South America (see Materials and Methods).…”

Mycotoxin Contamination in the EU Feed Supply Chain: A Focus on Cereal Byproducts

“…Unlike the situation for DON, the DON glucoside was not concentrated into DDGS, indicating that some DON glucoside may have been hydrolyzed during the fermentation process and that the ethanol yeasts may hydrolyze the conjugate [ 114 ]. An average increase of three times the fumonisin concentration in DDG has been reported by Bowers and Munkvold [ 112 ].…”

“…Regarding the variability in DDGS nutrient contents, the level of mycotoxin contamination in DDGS depends on the original grain contamination, processing methods, storage conditions, fermentation yeast properties, and year of production [ 108 ]. Although a slight degradation of fumonisins during fermentation has been reported [ 112 ], mycotoxins are not destroyed during the ethanol fermentation process or during the production of DDGS. It is generally accepted that some mycotoxins occur in DDGS, representing a potential health and economic risk of ethanol production from corn and a limit for their use in the animal feed industry [ 106 ].…”

Effect of Prothioconazole Application Timing on Fusarium Mycotoxin Content in Maize Grain

“…However, maize contaminated with 5000 g/g of fumonisins has been observed to cause anorexia in swine . Furthermore, a 3-fold accumulation in DDGS has also been reported for total fumonisins in laboratory scale experiments, which can seriously affect the versatility of DDGS as a livestock feed source. In 2002, the International Agency for Research in Cancer classified FB 1 as a possible esophageal carcinogenic factor to humans (Group 2B). , The European Commission fixed a maximum permitted level of 1000 ng/g for fumonisins, 8 + 9 , in maize and maize-based foods intended for direct human consumption with the EC Regulation n. 1126/2007 (to be applied from 1 October 2007) .…”