Isolation and metabolite production by Penicillium roqueforti, P. paneum and P. crustosum isolated in Canada

Abstract

Penicillium roqueforti, P. crustosum and P. paneum grow on ensiled grain and recycled feed unless properly treated. The former two species occur also on cut lumber in Canada. These are known to produce a number of secondary metabolites including roquefortine. In cooler dairy production areas, including Scandinavia and North America, cattle toxicosis has been associated with silage contaminated by these fungi. We collected strains associated with cow or cattle toxicoses. The principal metabolites were determined making use of a new extraction method and analysis combining HPLC, LC/MS/MS, and LC/NMR. Penicillium roqueforti and P. crustosum required amino acid nitrogen for metabolite formation and their toxins were formed under conditions of low oxygen (20-30% saturation). Production of roquefortine C occurred on depletion of the available nitrogen and penitrem A on depletion of carbon source. Yield was reduced by excess carbon. Medium osmotic tension (aw) affected metabolite production by the two species differently. Penicillium paneum was associated with ill-thrift of dairy cows and P. roqueforti was associated with more serious symptoms. Our data suggest a physiological basis for the common occurrence of roquefortine C in silage without serious consequences and the alternative, the presence of roquefortine C and toxicoses. The strain isolated from lumber was the best producer of the toxins studied. This is the first report of the toxigenic potential of P. roqueforti and P. paneum from Canada.

Influence of intraspecific variability and abiotic factors on mycotoxin production in Penicillium roqueforti

“…In the studied conditions, there was no significant effect of ROQC amino-acid precursor addition on the PTX.PR.18.3 strain mycotoxigenic potential, whereas a pH increase to 6.5 led to a slight but significant decrease in MPA production. These results are in agreement with the study of Sumarah et al (2005) who showed no significant changes in ROQC production with different nitrogen supply, indicating that production of ROQC is not enhanced in the presence of its precursors. The addition of MPC also significantly decreased both ROQC and MPA production.…”

Mycotoxins in small grains and maize: Old problems, new challenges

“…This issue remained unresolved and largely ceased to be a practical problem. More recently, P. roquefori sensu lato has been associated with reports of two syndromes in cows: serious toxicoses associated with P. roqueforti and a general ill-thrift associated with P. paneum (Sumarah et al 2005). Both of these fungi produce roquefortine but the former produces PR toxins and the later festuclavine, a compound long associated with ill-thrift in cows O'Brien et al 2006).…”

Mycotoxins and Other Secondary Metabolites Produced in Vitro byPenicillium paneumFrisvad andPenicillium roquefortiThom Isolated from Baled Grass Silage in Ireland

“…This is the first report of the toxigenic potential of P. roqueforti and P. paneum growing on grass silage in Ireland. In a Canadian study (15) of mold spoilage of animal feeds, P. paneum was associated with ill-thrift of dairy cows, whereas P. roqueforti was linked to toxicoses in the animals. Owing to the large number of secondary metabolites produced by these two species in this and other studies, both in culture and in silage, there is a need to carry out multimycotoxin analysis on this feedstuff on a larger scale.…”