Formation of conidia in a saprophytic strain Claviceps paspali producing simple lysergic acid derivatives

A non-mutant saprophytic strain C. paspali which forms conidia both on a solid medium and during submerged fermentation is described. Conidiation proceeded in parallel with culture growth and production of alkaloids. The effect of composition of culture media on the intensity of conidiation is described.

D-lysergic acid activation and cell-free synthesis of D-lysergyl peptides in enzyme fractions from the ergot fungus Claviceps purpurea

The D-lysergic acid activating enzyme from the ergot fungus Claviceps purpurea was purified to near homogeneity. It has a native Mr of about 245,000 and in its denatured form is a single polypeptide chain of Mr 62,000. The enzyme catalyzes the ATP-pyrophosphate exchange reaction dependent on D-lysergic acid and, though much less, that dependent on dihydrolysergic acid. Western blot analysis of SDS electropherograms of crude protein extracts from C. purpurea using monospecific antibodies directed against the D-lysergic acid activating enzyme revealed the immunostaining of one particular band which was identical with that of the D-lysergic acid activating enzyme. No significant immunoreactive band with higher molecular weight was seen, which precludes the possibility that the enzyme had arisen from the proteolysis of a high molecular weight ergot peptide synthetase. An ammonium sulfate fractionated enzyme fraction was prepared from C. purpurea strain C1 that catalyzed the incorporation of D-lysergic acid into two peptides which besides D-lysergic acid contained alanine, phenylalanine, and proline. Dihydrolysergic acid was efficiently incorporated into the corresponding dihydrolysergic acid containing analogues of the two compounds. Radiochemical analysis and degradation studies suggest that the two D-lysergic acid containing peptides most probably are N-[N-(D-lysergyl)-L-alanlyl]-L-phenylalanyl-L-proline lactam and N-[N-(D-lysergyl)-L-analyl]-L-phenylalanyl-D-proline lactam, respectively. N-[N-(D-Lysergyl)-L-alanyl]-L-phenylalanyl-L-proline lactam is considered to be the immediate precursor of ergotamine.(ABSTRACT TRUNCATED AT 250 WORDS)

Saprophytic production of clavine alkaloids and activity of hydroxymethylglutaryl-CoA reductase

In submerged Claviceps cultures the activity of hydroxymethylglutaryl-CoA reductase preceded the increase of alkaloid production and of sterol content. During the first alkaloid phase, cell mevalonate was involved in the biosynthesis of both alkaloids and steroids. In the second production phase, it was predominantly used for alkaloid synthesis. Hydroxymethylglutaryl-CoA reductase appears to be a suitable target for physiological manipulation to increase clavine alkaloid yields.

[Alkaloid production in the fungus Penicillium sizovae]

The dynamics of production of agroclavine-I and epoxyagroclavine-I, the basic components of the Penicillium sizovae alkaloid fraction, was being studied. The biosynthesis of alkaloids occurs in two stages coinciding in time with the growth phases. The culture studied is shown to have a considerably higher content of extracellular alkaloids than that of the mycelium. When the culture is grown on a medium with mannitol and succinic acid, separate consumption of carbon sources is observed. The alkaloid production in P. sizovae occurs in the presence of high residual concentrations of phosphorus in the medium.

[Effect of the cultivation conditions on alkaloid biosynthesis by Penicillium gorlenkoanum]

The effect of a carbohydrate component of the medium, trace elements and aeration on biosynthesis of the alkaloids costaclavine and epicostaclavine was studied with Penicillium gorlenkoanum. Alkaloid biosynthesis was shown to depend on the nature of a carbohydrate component: virtually no alkaloids were accumulated in media with glucose and fructose although these were synthesized at a high rate in a medium with mannitol. The quantity of synthesized alkaloids and the dynamics of the biosynthesis depended on carbohydrate concentration. The growth and alkaloid synthesis were influenced by traces of zinc, iron, copper and manganese. A more intensive aeration stimulated biomass accumulation but suppressed alkaloid biosynthesis.

Production of fumigaclavine A by Aspergillus tamarii Kita

Aspergillus tamarii Kita. isolated from seeds of Paspalum scrobiculatum L. is found to produce ergot alkaloids in submerged culture. The culture filtrate and mycelium are observed to contain 0.125 mg/mL and 1.2 mg/g (dry weight) total alkaloids consisting of 86.5 and 91.3% fumigaclavine A, respectively. The identification of the compound was confirmed by high-performance liquid chromatography, ultraviolet, infrared, and mass spectrophotometry analyses. This is the first report of the production of ergot alkaloid by this fungus. The possible role of fumigaclavine A as a mycotoxin is discussed.

Influence of tryptophan and related compounds on ergot alkaloid formation in Claviceps purpurea (FR.) Tul

L-Tryptophan did not exert any influence on peptide alkaloid formation in an ergotamine and in an ergosine-accumulating C. purpurea strain. A different picture was observed in a series of related C. purpurea strains. Tryptophan showed a slight stimulatory effect on the ergotoxine producer Pepty 695/S. A blocked mutant of it, designated as Pepty 695/ch which was able to accumulate secoclavines gave similar results. In a high-yielding elymoclavine strain Pepty 695/e, the progeny of the former one, tryptophan up to a concentration of 25 mM stimulated remarkably clavine biosynthesis. Furthermore, tryptophan could overcome the block of synthesis by inorganic phosphate. Increased specific activities of chanoclavine cyclase but not DMAT synthetase were observed in cultures of strain Pepty 695/e supplemented with tryptophan. 5-Methyltryptophan and bioisosteres of tryptophan were ineffective in alkaloid stimulation. These results are compared with those obtained with the grass ergot strain SD 58 and discussed with the relation to other induction phenomena.

Biosynthesis of penitrems and roquefortine by Penicillium crustosum

Roquefortine and the penitrems were biosynthesised concurrently at an approximately equimolar rate by Penicillium crustosum after growth and sporulation. [14C]mevalonic acid was incorporated (15% efficiency) into the isoprenoid regions of the penitrem and roquefortine molecules to an extent consistent with their 6:1 molar ratio of isoprenoid components. [14C]penitrem A (specific activity, 3.4 X 10(2) mu Ci mmol-1) and 14C-penitrems B, C, and E readministered to young cultures were metabolically interconverted, indicating considerable metabolic flux, though generally directed towards penitrem A as the end product and suggesting a metabolic grid for the penitrem metabolites. Addition of bromide to the medium preferentially favored the production of bromo-analogs rather than the usual chloropenitrems.

Changes in cytoplasmic ultrastructure during submerged cultivation of a peptide alkaloids-producing strain of Claviceps purpurea (Fr.) Tul

A strain of Claviceps purpurea, designated Pepty 695/S produces ergotoxine alkaloids under particular conditions of fermentation. The onset of alkaloid synthesis occurs around the second day of cultivation. Alkaloid formation is connected with morphological and ultrastructural changes. In the first 3-5 days of cultivation short thickened, septated hyphae, organized in plectenchymatic pellets as well as large single cells are formed. The hyphae are ultrastructurally characterized by increasing number of lipid droplets, deposits of glycogen and by extended ER membranes, which apparently may form numerous vesicles. The correlations between lipid and alkaloid synthesis are discussed.

[Effect of the age of the culture and the composition of the medium on alkaloid biosynthesis by Penicillium gorlenkoanum]

The production of the alkaloids costaclavine and epicostaclavine by Penicillium gorlenkoanum was studied as a function of the culture age and the composition of the growth medium. The alkaloids were found in the mycelium and, in great quantities, in the cultural broth. The production of the extracellular alkaloids started from the first days of growth and run in parallel to the biomass accumulation; the synthesis of costaclavine and epicostaclavine was maximal at the end of the logarithmic-stationary growth phases. The medium supplied with mannitol, succinic acid and 1% KH2PO4 was optimal for epicostaclavine synthesis. A carbohydrate or organic acid substitution as well as a variation in the concentration of phosphate changed the proportion between epicostaclavine and costaclavine contents. The biosynthesis of epicostaclavine was inhibited almost entirely by the glucose deficiency (2%) in the medium. This glucose concentration, phosphate excess (10 g/l), and the presence of citric or tartaric acids created favourable conditions for costaclavine biosynthesis.

N-demethylation of lergotrile by Streptomyces platensis

Thirty-eight microorganisms were screened for their ability to produce metabolites of the semisynthetic alkaloid, lergotrile. A total of five microorganisms were found to biotransform lergotrile, and N-desmethyl lergotrile was detected as the principal metabolite with most organisms. Streptomyces platensis (NRRL 2364) appeared to form the metabolite in highest yield, and a preparative-scale conversion was accomplished with a recovered yield of 50%. Structure proof was accomplished with comparative thin-layer chromatography, mixed melting point, mass spectrometry, and remethylation to lergotrile.

Directed biosynthesis of analogues of ergot peptide alkaloids with Claviceps purpurea

Analogues of peptide ergot alkaloids can be obtained by feeding a producing culture of Claviceps purpurea with an analogue of one of the amino acids of the peptide chain of the alkaloid.

[Differences in proline metabolism of a peptide alkaloid producing and a nonproducing strain of Claviceps purpurea]

Two strains (pepty 695 and pur 221) of Claviceps purpurea have been used to study the dependence of proline turnover on incubation time (1, 3, 6, and 12 hours) under different culture conditions (synthetic saccharose-citrate medium NL 720 and complex wort medium M 107) by means of tracer technique. In the saprophytically ergotoxine producing strain pepty 695 the proline is utilized in the protein and alkaloid biosyntheses. On the other hand, under non-producing conditions (M 10) the radioactivity of proline-14C is incorporated into many fractions and finally into CO2. In submerged culture (NL 720) the Claviceps strain pur 221 which does not produce ergolines uses proline only to a small extent in the protein biosynthesis, while most of this amino acid is not metabolized. The extent of uptake of proline is not correlated with the alkaloid synthesis. For comparison the turnover of L-glutamate-14C and D,L-ornithine-1-14C by strain pepty 695 cultivated in the NL 720 medium has been studied.

Production of peptide ergot alkaloids in submerged culture by three isolates of Claviceps purpurea

Three strains of Claviceps purpurea (Fr.) Tul., isolated from sclerotia grown on rye, produce under submerged conditions ergocryptine and ergotamine, ergocornine and ergosine, and ergocristine, respectively. All of the strains either lacked the ability to produce conidia or formed them sparingly, but they accumulated large quantities of lipids and sterols. The fermentations are typically divided into two phases. The first is characterized by the rapid utilization and exhaustion of the phosphate contained in the medium, rapid uptake of ammonium nitrogen and of citric acid, rapid growth, and low alkaloid production; the second phase is characterized by slower growth and by a marked accumulation of lipids, sterols, and alkaloids.