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Four new steroidal glycosides, named capsicosides A–D together with proto-degalactotigonin, were isolated from the roots and seeds of Capsicum annuum var. conoides and Capsicum annuum var. fasciculatum. On the basis of detailed chemical and spectroscopic evidence, the structures of capsicosides A–D were shown to be furostanol glycosides corresponding to gitogenin and tigogenin oligoglycosides. Capsicoside A was regarded as the same compound as the previously described capsicoside, whose structure now needs to be revised according to the data presented in this report.

Spore germination of net-producing nematophagous fungi can lead to either immediate formation of the trap or, more usually, the production of a single hypha upon which nets are eventually produced. However, in isolates of Arthrobotrys conoides and A. cladodes, spores on blocks of water agar were observed to germinate and fuse readily with adjacent spores or vegetative hyphae. Where spores of A. conoides had fused with each other, usually only a single hypha grew from them, indicating that this may provide more nutrient for the developing hypha. Alternatively, fusion of spores may merely reflect the tendency of hyphae of these fungi to anastomose.

Summary Lipids, cholesterol and activity of certain key enzymes involved in the biosynthesis of steroids, viz., steroid dehydrogenases, reduced nicotinamide adenine dinucleotide (NADH) diaphorase and glucose-6-phosphate dehydrogenase (G-6-PDH) have been studied by means of cytochemical methods in different stages of the life-cycle of the gregarine Stylocephalus conoides . All the aforesaid precursors and the enzymes have been detected in the trophozoite of this gregarine indicating the organism's steroidogenic potential.

Induction of trap formation in Arthrobotrys oligospora, A. conoides and Monacrosporium cystosporum was studied during a 24 h period in the presence of the free-living nematodes Panagrellus redivivus on various nutrient media. A definite pattern of trap formation was observed in these fungi. Low nutrient mineral salt medium had the most pronounced effect on trap formation. Attraction and repulsion of P. redivivus towards these three nematophagous and three non-nematophagous fungi was studied. The nematodes were attracted towards three nematophagous and one non-nematophagous fungi, the other two repelled them. Attractants of the nematophagous fungi were determined by thin-layer chromatography. In the case of A. oligospora and M. cystosporum, four spots were traced, whereas in A. conoides, five spots were detected.

An experiment of central composite design was performed to determine simultaneously the most suitable concentration of each of three nutrients essential for proliferation of the nematode-trapping fungus, Arthrobotrys conoides , and to detect any significant interaction that occurred when they were supplied at different levels. Regression analyses of the results obtained revealed that for maximal growth of A. conoides in a glucose-inorganic salts medium, biotin, thiamine, and zinc were required at concentrations of 5, 100, and 400 μg/liter, respectively. No interaction of significance was detected. The analytical procedures are presented in detail, and the benefits that accrue from a statistical approach are discussed.

Coscarelli, Waldimero (Rutgers, The State University, New Brunswick, N.J.) and David Pramer . Nutrition and growth of Arthrobotrys conoides . J. Bacteriol. 84: 60–64. 1962—Despite its ability to capture, kill, and subsist on nematodes, the predacious fungus Arthrobotrys conoides does not demonstrate a unique nutritional pattern. Yeast extract, required for growth in a glucose-inorganic salts medium, was replaced by biotin, thiamine, and zinc. Biotin biosynthesis by the fungus is blocked at the desthiobiotin to biotin conversion. A. conoides is unable to synthesize either of the two moieties of thiamine but, when supplied with pyrimidine and thiazole, completes biosynthesis of the vitamin via a coupling reaction. A chemically defined medium that supports rapid and abundant growth of A. conoides is described. Glucose is utilized efficiently (economic coefficient of 31.8 to 42.8), and yields exceeding 9 g (dry wt) of fungus tissue per liter of medium are obtained.

SUMMARYNine varieties and forms of Capsicum annuum Linn. have been examined as regard their karyotype. Most of the varieties represent 2 n = 24 chromosomes. Many derived forms of Var. grossum and Var. conoides show 2 n = 36 and 48 chromosomes. It has been assumed that both polyploidy and structural alteration of chromosomes have played important roles in the evolution of the varieties. From the chromosome morphology and number, it appears that Var. acuminatum is the most primitive variety, while Var. grossum is most advanced. Var. longum represent a distinct line of evolution.

Bonner (1947) reported that acrasin caused the aggregation of Dictyostelium discoideum Raper amoebae. The primary purpose of our study was to determine the nematode attraction ability of a predaceous fungus extract. The nematode-trapping fungus, Arthrobotrys musiformis Drechs. (NH45), used in this study was obtained from Dr. Roderick C. Cooke. Department of Botany, University of Sheffield, Sheffield, England. The fungus-feeding nematode, Aphelenchus avenae Bastian and its nonpredaceous fungal host Pyrenochaeta terrestris (Hansen) Gorenz., Walker and Larsen, was obtained from Dr. Donald Taylor, Department of Plant Pathology, University of Illinois, Urbana. Stock cultures of both the predaceous fungus and the mycophagous nematode were maintained on agar media at room temperature according to the procedure described by Monoson (1968). Arthrobotrys musiformis grew saprophyticly in petri dishes that contained 2 per cent Difco corn-meal agar (20 g Difco corn-meal agar in 1,000 ml of water) at 27 C in the absence of nematodes. However, the addition of either living nematodes or the body fluids of nematodes caused the formation of adhesive-network traps that are characteristic of the fungus. The morphogenetic change of A. musiformis was similar to that reported by Pramer and Stoll (1959) for A. conoides Drechs. Nematodes were observed to move around and through the traps of A. musiformis. Nematode movements did not appear random and suggested that these animals were attracted to the fungus, predaceous structures. A series of experiments were conducted to determine whether or not liquid extracts of the fungus contained a nematode attraction substance(s). ouse, B. B. 1947. A survey of the dis omycete flora of the Olympic Naal Park and adjacent reas. Mycologia 39: 635-689. a , C. G. 1958. Host fungus index for the Pacific Northwest II. Fungi. ash. Agr. Expt. Sta. Circ. 336. 237 p. 628

The induction of traps by the nematode Panagrellus silusiae in four fungal isolates of Dactylaria brochopaga and Arthro-botrys conoides was strongly influenced by several species of bacteria, which increased the yield mostly in light. In darkness with a stagnant atmosphere and a developing mycelium their effects were drastically altered; some bacteria then promoted the appearance of an abundance of megatraps in Dactylaria brochopaga.

Seventeen saccharides were tested for their ability to bind to the trap lectins of three species of nematode-trapping fungi and prevent nematode capture. The lectin of Arthrobotrys conoides was found to be inhibited by α- d -glucose/ d -mannose and similar saccharides. The lectins of Monacrosporium eudermatum and Monacrosporium rutgeriensis were inhibited by α- l -fucose and 2-deoxy- d -glucose, respectively. Human group O(H) erythrocytes agglutinated to traps of M. eudermatum but not A. conoides or M. rutgeriensis. There was no agglutination of group A or B to traps formed by all three fungi. Exposure of the traps to trypsin eliminated the ability to capture nematodes. The presence of d -glucose/ d -mannose and l -fucose residues on the nematode cuticle was suggested through the use of commercially prepared lectin-peroxidase conjugates.

The nematode-trapping fungus Arthrobotrys conoides grows as typical vegetative hyphae on laboratory media containing glucose or starch as sole carbon source. However, in the presence of nematodes, "nemin", and several of the aliphatic amino acids (such as valine), this predacious fungus forms traps which are composed of sticky loops. The present studies show that, when A. conoides is grown on a semisynthetic medium in which various carbohydrates are substituted for glucose as the carbon source available for growth, the nature of the carbohydrate exerts a major effect on the induction of trap formation.

In vitro growth studies showed that Arthrobotrys oligospora Fresenius, A. conoides Drechsler, A. musiformis Drechsler, and A. robusta Duddington are characterized by a fast, inherent growth rate relative to A. dactyloides Drechsler, Dactylella gephyropaga Drechsler, and Dactylaria brochopaga Drechsler, which grew slowly on all media tested. Arthrobotrys superba Corda, Dactylella ellipsospora Grove, and D. asthenopaga Drechsler were found to be intermediate in this respect. There was little correlation between the maximum rate of increase in colony diameter of the 10 species of nematophagous Hyphomycetes and their ecological requirements for such growth. The fast-growing species appeared to prefer media with a pH range of 5.0–6.0 and the slow-growing fungi a pH of about 4.0. No consistent similarity in environmental requirements was found among species of fungi belonging to the same genus or between those possessing the same kind of nematode-trapping organ. Lima bean agar of pH 5.0 was a satisfactory culture medium and incubation at 25 °C in continuous or intermittent light resulted in larger colonies than incubation in darkness.

Linoleic acid was shown to be the only detectable nematicidal agent in the mycelial extracts of several predacious fungi of the genus Arthrobotrys. Although the compound is present in saprophytic cultures, induction of trap formation by nematodes or phenylalnyl-valine caused a significant increase in its production. In submerged cultures, the number of traps formed by Arthrobotrys conoides and Arthrobotrys oligospora was directly correlated to the increase of the concentration of linoleic acid. In A. conoides, the ratio of ergosterol to linoleic acid decreased from 2.6 in saprophytic cultures to 1.1 in trap-forming cultures induced with nematodes. Linoleic acid exhibited nematicidal activities towards the free-living nematode Caenorhabditis elegans with an LD50 value of 5 μg/ml.

CARBON dioxide has been shown to influence morphogenesis in micro-organisms, higher plants and animals. Among the processes affected by carbon dioxide (or bicarbonate) concentration are sporangial differentiation in Blastocladiella emersonii1, mould-yeast dimorphism2,3, spherulation in Coccidioides immitis4, sporulation by bacteria5 and fungi6,7, root development by pea8, and sexual differentiation in Hydra9. This list can now be extended to include morphogenesis in Arthrobotrys conoides. A. conoides is a nematode-trapping fungus which captures prey in adhesive networks of hyphal loops. Usually, these organelles of capture are not formed spontaneously by the fungus but develop in response to the presence of prey. Morphogenesis is induced by a metabolic product of nematodes which has been partially purified10–12 and designated nemin13. The tests described here provide evidence that nemin-induced morphogenesis in A. conoides is dependent on carbon dioxide.