Cytochemische Darstellung von Peroxisomen in Pilzzellen

Zusammenfassung Mit Hilfe der cytochemischen Methode vonFahimi (1968) wurde in den Zellen der PilzeNeurospora crassa, Rhizopus nigricans undSaccbaromyces cerevisiae das Enzym Katalase in distinkten Granula nachgewiesen. Die Spezifität der Färbereaktion wurde durch ihre Hemmbarkeit mit 3-Amino-1,2,4-triazol gezeigt.

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Cytochemical localization of peroxisomes in fungal cells

Summary In the cells of the fungiNeurospora crassa, Rhizopus nigricans, andSaccharomyces cerevisiae catalase was detected in distinct granula with the cytochemical procedure ofFahimi (1968). The specificity of the staining reaction was demonstrated by the inhibitory action of 3-amino-1,2,4-triazole.

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Frau Prof. Dr. B.Haccius danke ich für die Überlassung der Pilzkulturen.     

Fungistatic Activity of Essential Oils from Ocimum basilicum Chemotypes

Essential Oils from Ocimum basilicum and their components showed different inhibition effects against Fusarium oxysporum f. sp. vasinfectum and Rhizopus nigricans, The different antifungal activity of the essential oils is determined mainly by the percentage of the main components: cineol, linalool, methylchavicol and eugenol.     

ISOELECTRIC POINTS FOR THE MYCELIUM OF FUNGI

1. Mycelium of Rhizopus nigricans when stained with certain acid and basic dyes and washed with buffer mixtures of 0.1 M phosphoric acid and sodium hydroxide responded much like an amphoteric colloid with an isoelectric point near pH 5.0. 2. When grown on potato dextrose agar the reaction of which was varied with phosphoric acid the extent of colony growth of Rhizopus nigricans plotted against the initial Sörensen value of the agar produced a double maximum curve with the minimum between the two maxima at initial pH 5.2. 3. When grown in potato dextrose broth the reaction of which was varied with phosphoric acid the dry matter produced by Rhizopus nigricans plotted against the Sörensen value of the broth produced a double maximum curve with the minimum between the two maxima at initial pH 5.2 or average pH 4.9. 4. Mycelium of Rhizopus nigricans placed in buffer mixtures of 0.01 M phosphoric acid and sodium hydroxide of pH 4.1 to 6.3, changed the reaction in most cases toward greater alkalinity. 5. Mycelium of Fusarium lycopersici stained with certain acid and basic dyes and washed with buffer mixtures of 0.1 M phosphoric acid and sodium hydroxide responded much like an amphoteric colloid with an isoelectric point near pH 5.5.     

Hemolytic activity of Rhizopus nigricans and Rhizopus arrhizus

Rhizopus nigricans andR. arrhizus were cultured in modified Sabouraud broth and synthetic dextrose-glutamate medium for periods of two to eight weeks. The culture filtrates and extracts of fungous mats were examined for the presence ofin vitro hemolytic activity. The culture filtrates exhibited little hemolytic activity but all fungous mat extracts produced hemolysis of sheep, rabbit, guinea pig and human erythrocytes. Guinea pig erythrocytes were in general most readily hemolyzed and sheep erythrocytes least readily hemolyzed.

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Zusammenfassung Rhizopus nigricans undR. arrhizus sind in modifizierter Sabouraud's Brühe und in synthetischem Dextroseglucamate-Nährboden für zwei bis acht Wochen gezüchtet worden. Das Kulturfiltrat und der Extrakt des Pilzmyzeliums sind für das Vorhandensein der in-vitro hämolytischen Aktivität untersucht. Das Kulturfiltrat zeigte eine geringe hämolytische Aktivität, jedoch verursachten alle Pilzmyzeliumextrakte eine Hämolyse in Erythrozyten von Schaf, Kaninchen, Meerschweinchen und Menschen. Meerschweinchenerythrozyten sind im allgemeinen am leichtesten, Schaferythrozyten am wenigsten hämolysiert.

     

Studies of a pelleted growth form of Rhizopus nigricans as a biocatalyst for progesterone 11α-hydroxylation

The noncoagulative type of pellet formation can be induced in submerged cultivation of the filamentous fungus Rhizopus nigricans. The size and constitution of the hyphal agglomerates obtained varied with changes in inoculum size and agitation speed for given media composition and cultivation conditions. The physiological state of mycelium, used for a further process of biotransformation, was estimated by following the growth kinetics, pH value and substrate utilization during submerged cultivation. Namely, differences in pellet morphology and physiology affect the ability of R. nigricans to hydroxylate progesterone at the 11α position. A repeated batch procedure revealed the best maintenance of biotransformation capacity for pellets, obtained from the growth phase of cultivation at high agitation speed and with low inoculum size.     

Aflatoxin production by Aspergillus parasiticus in a competitive environment

Aspergillus parasiticus NRRL 2999 was grown in the presence of Rhizopus nigricans, Saccharomyces cerevisiae, Acetobacter aceti, or Brevibacterium linens and aflatoxin concentration was determined after 3,5,7, and 10 days of incubation at 28C. R. nigricans and S. cerevisiae inhibited growth and aflatoxin production by A. parasiticus. B. linens caused slight inhibition and A. aceti stimulated growth and aflatoxin production by A. parasiticus.     

Fermentation of millet to produce kamu a Nigerian starch-cake food

Microorganisms present in the unfermented grains of millet at the Initial stage of steeping and after sieving at the initial stage of souring for the preparation of kamu were moulds (Aspergillus versicolor, Penicillim nigricans and Rhizopus stolonifer), bacteria (Pediococcus pentosaceus and Lactobaclllus plantarum) and a yeast (Saccharomyces cerevisiae). Only the bacteria and yeast persisted to the end of the steeping period. These, together with another yeast, Candida krusel, brought about the final souring of kamu.     

Preliminary characterization of the hemolysin of Rhizopus nigricans

A hemolysin was extracted from fungous mats ofRhizopus nigricans cultured for two weeks in modified Sabouraud broth. Preliminary characterization indicated that the active substance is water soluble, stable after heating to 100°C, not destroyed by proteolytic enzymes, not dialyzable, and not precipitable with ethanol. It is however precipitable with ammonium sulfate and extractable with lipid solvents. Lipid fractionation revealed activity in the non-acidic phospholipid fraction. The cumulative findings suggest that the active hemolytic substance is a lipid perhaps attached to a protein.

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Zusammenfassung Das Hämolysin war vom Pilzmyzelium vonRhizopus nigricans extrahiert worden, das in Sabouraud's Brühe für zwei Wochen gezüchtet worden ist. Vorläufige Charakteristik zeigte, daß die aktive Substanz wasserlöslich, hitzeresistent ist und sie durch proteolytische Fermente nicht zerstört wird. Sie ist dialysierbar, und wird durch Ethanol nicht prezipitiert. Jedoch ist sie durch Ammoniumsulfate prezipitiert und durch Fettlösungsmittel extrahierbar Lipoidfraktionierung zeigte eine Aktivität in der nich-saueren Phospholipoidfraktion. Kumulative Befunde legen es nahe, daß die aktive, hämolytische Substanz ein an Protein gebundenes Lipoid ist.

     

The growth form of the inducing microorganism and chitin addition affect mycolytic enzyme production byTrichoderma harzianum

The effect of the growth form of the inducing microorganism on specificTrichoderma harzianum mycolytic enzyme production was studied. The pelleted form ofRhizopus nigricans gave a better product concerning protoplast formation ability. The maximum yield of protoplasts from the target fungusCochliobolus lunatus was 1×10⁸ ml^–1. Analysis of individual specific enzyme activities inTrichoderma mycolytic enzyme preparations confirms the importance of high chitinase and low protease activity for high protoplast yields. Supplementation of the production medium with chitin increased the chitinase activity in theTrichoderma exoenzyme mixture.     

Effects of perfluorinated oxygen carrier application in yeast, fungi and plant cell suspension cultures

The growth of the yeast Saccharomyces cerevisiae, the fungus Rhizopus nigricans and Nicotiana tabacum cells with perfluorodecalin as an oxygen carrier has been studied. The volumetric mass transfer coefficient (k_La) measured by the dynamic method was higher for the perfluorodecalin oxygenation system than for the conventional aeration system. The results show that perfluorocarbon can be successfully used as an efficient gas carrier, especially for the culture of delicate plant cells. The increase in yeast biomass in the suspension culture aerated by perfluorodecalin was as much as 110% higher than in the culture aerated by air. The fungus R. nigricans grew better when the conventional aeration system was used due to the fact that growth of the mycelium is limited by the transport of oxygen by diffusion in the pellets rather than by interfacial oxygen transport. In the case of isolated tobacco cells, an increase of over 350% in biomass growth was observed for the PFC aeration system.     

The Immunoregulatory Effects of Endoglucanase Preparations on Plant Resistance to Fungal Infections

The effects of enzymatic preparations—pectomacerin, hemicellulase, andTrichoderma viride 13/10 cellulase—on plant immunological status were studied using two pathosystems, carrot root–white rot agent (Sclerotinia libertiana) and carrot root–black rot agent (Rhizopus nigricans) as examples. It was demonstrated that these preparations reduced the plant damage by infections, namely, decreased the permeability of cell membranes in the infected tissue and stimulated its defense responses, which were expressed as a stable elevation in the content of phenolic compounds and formation of tissue protective barriers.     

The Alkaloids of Fungi

Examination of different species of local fungi, grown on two nutritive solutions of different composition, for alkaloid formation was investigated. The formation of alkaloids was confined to four species, namely: Geotrichum candidum, Mucor hiemalis, Aspergillus flavus and Rhizopus nigricans. A comparative study of the growth as well as the formation of alkaloids by these species and by Claviceps purpurea NRRL was carried out. Methods were also described with which the different alkaloids produced by the experimental strains were identified. Peptides as well as clavine type alkaloids were detected in all cases except with Mucor hiemalis where a compound corresponding to ergosine was the only alkaloid present.     

Post-harvest diseases of tomato in india

Summary A systematic account of nine fungal diseases of tomatoes caused byAlternaria tenuis, Colletotrichum dematium, Cladosporium fulvum, Fusarium roseum, Malustela aeria, Myrothecium roridum, Oospora lactis f. parasitica, Phoma sp. andRhizopus nigricans during storage has been given. Except Oospora rot the other diseases included in the present paper have not been recorded previously from India. Post-harvest decay of tomatoes due toMalustela aeria has not been described from any part of the world and is new to science.     

Production of endopolygalacturonase fromRhizopus nigricans related to the evolution of growth substrate

Summary Endopolygalacturonases production byRhizopus nigricans is studied. The enzymatic level present during the early growth stages depolymerized fully the substrate and afterwards the growth of the fungi, with the parallel production of endopolygalacturonase, began. The maximum level of enzymatic activity was 18 U/mL and was reached six days after the maximun metabolic activity of the fungi. The production of endopolygalacturonase finished when the carbon source was exhausted.     

Variability for restriction fragment lengths and phylogenies in lentil

Summary Thirty accessions of domesticated (Lens culinaris ssp. culinaris) and wild (L. culinaris ssp. orientalis, L. culinaris ssp. odemensis, L. nigricans ssp. ervoides and L. nigricans ssp. nigricans) lentil were evaluated for restriction fragment length polymorphisms (RFLPs) using ten relative low-copy-number probes selected from partial genomic and cDNA libraries of lentil. Nei's average gene diversity was used as a measure of genetic variability for restriction fragment lengths within subspecies and a dendrogram was constructed from genetic distance estimates between subspecies. The wild lentils L. culinaris ssp. orientalis and L. culinaris ssp. odemensis showed the greatest variability for restriction fragment lengths and were closely positioned to domesticated lentil in the dendrogram. Little variability for restriction fragment lengths was observed within accessions of L. nigricans ssp. ervoides and L. nigricans ssp. nigricans. This observation is consistent with a previously published proposal that nigricans may have been independently domesticated. Estimates of genetic variability based on RFLPs tended to be greater than estimates from isozymes.     

Bio-activity of fungal culture filtrates against root-knot nematode egg hatch and juvenile motility and their effects on growth of mung bean (Vigna radiata L. Wilczek) infected with the root-knot nematode,Meloidogyne incognita

Culture filtrates of selected soil fungi, namely Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Fusarium oxysporum, Penicillium vermiculatum and Rhizopus nigricans exhibited variable response to egg hatching and mortality of the root-knot nematode, Meloidogyne incognita. Higher concentrations of the culture filtrates of all the fungi inhibited egg hatching and proved to be toxic to the juveniles of M. incognita. In addition, development of the gall and multiplication of M. incognita were also found adversely affected in varying degrees on all the plants of Vigna radiata treated with the filtrates. The culture filtrate of A. niger showed highest toxicity to the nematode than those of any other fungus tested. Soil drench application of the culture filtrates gave better seedling growth and least nematode multiplication in comparison to seed soaking treatment.     

The use of a surface coating to ameliorate the rate of spread of post-harvest fungal diseases of top fruit

The impact of TAL Pro-long coatings (a sucrose-ester composition) on the development of some common post-harvest fungal rots of top fruit is reported. Coatings were not observed to be fungistatic but did diminish the incidence of fungal infections on Conference pears held in cold store. At higher temperatures coatings modified the spatial distribution and reduced the rate of spread of lesions within apples and pears. In comparison to experimental controls, TAL Pro-long had a greater effect on those rots caused by Botrytis cinerea Fr., Monilinia fructigena (Aberh. & Ruhl.) Honey and Rhizopus nigricans Lind. than those of Alternaria alternata Fr., M. laxa (Aberh. & Ruhl.) Honey and Penicillium expansum Link em. Thom. The efficacy of the treatments was related to the concentration of the preparations applied, the variety of fruit, the timing of application and the temperature to which produce were subsequently exposed.     

Fruiting-body formation, cultivation properties, and host specificity of a fungicolous fungus, Asterophora lycoperdoides

We report the fruiting-body formation and cultivation properties of Asterophora lycoperdoides, a fungicolous fungus. Asterophora lycoperdoides formed fruiting bodies on potato dextrose agar medium in approximately 1 week, although this fungus shows high host specificity to Russula nigricans in nature. Optimal temperature of mycelial growth and fruiting-body formation was 25°C. Mannitol or soluble starch was preferably used as a carbon source, and amino nitrogen was preferably used as the nitrogen source. For a better understanding of the relationship between A. lycoperdoides and R. nigricans, we cultivated A. lycoperdoides on media supplemented with freeze-dried fruiting bodies of various fungi. The germination rate was approximately 2.5 times higher on the medium containing freeze-dried R. nigricans than that on the PDA medium. The mycelia extended most rapidly in the presence of R. nigricans. Furthermore, the stipe length of its fruiting body was the longest on the medium containing R. nigricans. These results indicated that A. lycoperdoides can grow faster by utilizing certain substances that are abundantly contained in R. nigricans, such as mannitol, or by utilizing R. nigricans itself. It is considered that the constituents of R. nigricans might contribute to the host specificity of A. lycoperdoides.     

The food plant preferences of Phratora vitellinae (Coleoptera: Chrysomelidae)

In the Upper Rhine (Petite Camargue, Saint Louis, France) study site, Ph. vitellinae are found mainly on Salix nigricans on which they are bivoltine. Some beetles are occasionally observed on S. purpurea, especially in Spring, but never on S. alba, S. caprea and S. cinerea. In other European localities, S. nigricans or S. hegetschweileri at higher elevations are frequently recorded as host-plants. However, some populations are also found on S. purpurea, P. tremula and P. trichocarpa x deltoïdes, usually when neither S. nigricans nor S. hegetschweileri are present.All the Salicaceae on which Ph. vitellinae was observed in the field have leaves rich in phenylglycosides and with glabrous lower surfaces, at least in Spring. Ph. vitellinae was never recorded on those Salix species with leaf undersurfaces densely covered with trichomes.At the time of emergence of the beetles from hibernation, S. nigricans leaves are more developed than those of S. purpurea and S. cinerea. Moreover, those S. nigricans trees with the longer shoots in Spring support the largest number of beetles at their emergence. The preference of Ph. vitellinae for S. nigricans might be reinforced by these plenological differences.In the Petite Camargue, the same S. nigricans trees support the largest populations of beetles from one generation to the next and from year to year. This suggests that S. nigricans does not respond to defoliation with induced resistance to the beetles.All shoots on the branch seem to be equally suitable and attractive for oviposition. The older leaves at the base of the shoot and the younger ones at the top are less favored by ovipositing females. Survival of the egg batches and the groups of freshly emerged larvae is lower on the distal shoots of the branch and on the younger leaves. This might be due to a higher degree of exposure to predators.