Claviceps spp

Ergot is a fungal (Claviceps spp.) disease of cereal grains, including rye, from which various water-soluble toxins can be derived that, when ingested, cause abdominal cramps, spasms, and a form of gangrene. 

Taber, W.A, Vining, L.C. A Comparison of Isolates of Claviceps spp. for the Ability to Grow and to Produce Ergot Alkaloids on Certain Nutrients Can J. Microbiology (1960) 6 355-365... 

Claviceps spp. SG (from Setaria geniculata) and PM (from P. maximum). Conidial morphology of the latter two isolates was not sufficiently related to described teleomorphic species to allow for their unequivocal association. Claviceps sp. Hyp was described by Loveless (1964b, 1985) on various Hyparrhenia species. A characteristic of this species is wide truncated macroconidia. Sclerotia are hidden in glumes, and their germination was never... 

Directed biosynthesis is a possible method for the synthesis of new ergot alkaloid molecules and for probing the biosynthetic pathway by feeding Claviceps spp. with natural and unnatural amino acids and synthetic precursors. 

C,gH gN202, Mr 270.33, plates, mp. 264°C (decomp.). Metabolite of Claviceps spp. including C. fusiformis, cf. lysergic acid and ergot alkaloids. The biosynthesis... 

Acetylation of 23 to fumigaclavine A (24) is hypothesized to be catalyzed by the product of easN, which has high amino-acid-sequence identity with 0-acetyl transferases (65). No orthologue of this gene is found in the eas clusters of the Claviceps spp. Moreover, there is no other acetylation step in any part of the ergot-alkaloid pathway or its shunts. 

Analytical methods have so far concentrated mainly on ergot alkaloids from C. purpurea and few data are available for alkaloids from other Claviceps spp. infecting grain. Only a small number of aU ergot alkaloids are well characterized, and several unknown compounds including bound forms might contribute to the health hazard posed by food and feed contamination. 

Fig. 4.4 Biosynthesis of ergoline alkaloids 1. With the exception of chanoclavin-I add and cycloclavine (specific convolvulaceous constituents not found in fungi) aU alkaloids represent compounds occurring in both Claviceps spp. as well as in certain convolvulaceous spedes. Grey arrows indicate the principal pathway (main route), regular arrows side routes...

Fig. 4.6 Biosynthesis of ergoline alkaloids III. Formation of eigopeptines illustrated with the example of ergosine occurring in Claviceps purpurea and Ipomoea argyrophylla, respectively ergobalansine, to date not found as a metabolite of Claviceps spp., is a proline-free (highlighted in grey) constituent of the fungal genus Balansia as well as of Ipomoea asarifolia...

Fig. 4.7 Biosynthesis of ergohne alkaloids IV. Presumable formation of simple lysergic acid amides occurring in Claviceps spp. and certain convolvulaceous species lysergoyl adenylate is transformed to an enzyme-linked lysergoyl-L-alanine by a peptide synthetase different to LPS the low-molecular direct precursor of ergometrine released from the enzyme might be the corresponding aldehyde which in turn could be reduced in the last step the homologous lysergic acid a-hydroxyethylamide might be produced in a similar manner...

Biological, non-parasitic production of ergot alkaloids is carried out by saprophytic cultivation of production strains of different species of the genus Claviceps. The saprophytic cultivations of Claviceps spp. were experimentally performed as early as in the last century (Bove, 1970). Mycelial saprophytic cultures in nutrient media were reported since the 1920s (Bonns, 1922 McCrea, 1931 Schweizer, 1941 De Tempe, 1945). These experiments provided the basis of cultivation of the fungi Claviceps under artificial nutritional conditions but did not yet serve for alkaloid production or were not reproducible (McCrea, 1933). 

Selected high-yielding strains of Claviceps spp., similarly as those of other microorganisms, degenerate (Kobel, 1969). Also, problems of transfer of original cultures in a fermentation technological process are connected with this fact. Different producers of clavine alkaloids born to be transferred 6-9 times without decrease of producing capability (Malinka etai, 1988). 

Ergot alkaloids can be manufactured also by alternative fermentation processes, e.g. by those using nontraditional substrates or immobilized cells of Claviceps spp. or their subunits. Semicontinuous or continuous cultivations represent other alternatives of the saprophytic cultivation. 

Detoxification of methyl-N-methylanthranilate to methyl-anthranilate nsing a number of microorganisms, among others Claviceps spp., is described in the patent of Page et al. (1989). The detoxification was carried out in a 4-8-day fermentation process. 

Rylko, V., Flieger, M., Sajdl, P. and Reha k, Z. (1988b) Effects of inducers and inhibitors on ergot cytochrome P-450 and alkaloid production by Claviceps spp. Abstract Book, lUB 14tb Internal. Congr. Biochemistry, Prague, Czechoslovakia, July 10-15, IV, 94. 

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