Production of verruculogen by Penicillium estinogenum in stirred fermenters.

A spectrofluorometric assay for the estimation of the tremorgenic mycotoxin verruculogen in crude mycelial extract has been devised and used to determine concentrations as low as 0.2 microgram ml-1. Verruculogen production by Penicillium estinogenum has been extended from surface culture to submerged culture in 60 1 stirred fermenters, in which the maximum cell-associated mycotoxin yield [5 mg (100 ml culture)-1] was obtained within 7 d. It was found necessary to supplement the medium (Czapek Dox broth plus 0.5% yeast extract) with calcium chloride (2%) to induce profuse sporulation (2 X 10(7) conidia ml-1).

Clinical studies on tremorgenic mycotoxicoses in sheep.

The clinical responses of sheep dosed orally over seven to 14 weeks with the dried mycelium of a soil-borne mould containing the tremorgenic mycotoxin penitrem A are described. An initial tremoring response was gradually overshadowed by an incoordination syndrome similar to that seen in ryegrass staggers. In spite of protracted staggers symptomatology, correlated with in vitro changes in the release of neurotransmitter amino acids from corpus striatum nerve ending preparations, no histopathology was evident in the wide range of neural and other tissue studied. The biochemical nature of this reversible mycotoxicosis is discussed.