N. G. Vinokurova

Screening for Ergot Alkaloid Producers among Microscopic Fungi by Means of the Polymerase Chain Reaction

The potential of the polymerase chain reaction for the detection of ergot alkaloid producers among microscopic fungi of the generaPenicilliumand Clavicepswas evaluated. Twenty-three strains of various species of fungi with a previously studied capacity for alkaloid production were used. The internal fragment of the gene encoding 4-dimethylallyltryptophan synthase, the enzyme catalyzing the first step in the biosynthesis of ergot alkaloids, was amplified using degenerate primers. This approach revealed an about 1.2-kb specific DNA fragment in micromycetes synthesizing ergot alkaloids with complete tetracyclic ergoline system. Microorganisms that produce alkaloids with modified C or D ergoline rings, as well as α-cyclopiazonic acid, did not yield the PCR fragment of the expected size. This fragment was also not found in fungi incapable of ergot alkaloid production.

Mycotoxin production profiles of Penicillium vulpinum (Cooke & Massee) Seifert & Samson strains.

Mycotoxins produced by seven strains ofPenicillium vulpinum (formerlyPenicillium claviforme) isolated from different sources were studied. The strains were characterized by specific profiles of secondary metabolites and produced mycotoxins of different structural types. In addition to toxins already known for this fungal species (patulin, roquefortine, 3,12-dihydroroquefortine, oxalin, viridicatin, cyclopenin, and α-cyclopiazonic acid), the strains studied also produced indolyl-3-acetic acid, griseofulvin, meleagrin, and cyclopeptin.

Effect of microelements on the biosynthesis of secondary metabolites by the fungusPenicillium citrinum thom VKM F-1079

Penicillium citrinum VKM F-1079 was found to produce clavine ergot alkaloids and citrinin, a secondaryO-heterocyclic metabolite. Citrinin was produced in the idiophase, whereas the production of ergot alkaloids paralleled fungal growth. The addition of manganese ions to the growth medium stimulated the biosynthesis of both citrinin and ergot alkaloids. Zinc ions stimulated only citrinin synthesis. The presence of these microelements in the growth medium influenced the proportion between the ergot alkaloids synthesized. Copper, manganese, and iron ions slightly affected fungal growth and alkaloid production. The effect of microelements on the main kinetic parameters of growth and alkaloid production was studied.

Taxonomic position and nitrogen-containing secondary metabolites of the fungusPenicillium vitale pidoplichko et bilai apud bilai

The type strainPenicillium vitale Pidoplichko et Bilai apud Bilai 1961 VKM F-3624 was found to considerably differ from a sibling speciesP. janthinellium (syn.P. simplicissimum) in some physiological and morphological features (growth rates at different temperatures, the size of philiades, and the shape of conidia), as well as in the pattern of the nitrogen-containing secondary metabolites produced (roquefortine, 3,12-dihydroroquefortine, meleagrin, aurantioclavine, indole-3-acetic acid, andN-acetyltryptamine). The data obtained suggest thatP. vitale represents an independent species.