Showing papers on "Mycelium published in 1974"
TL;DR: The results support the hypothesis that mycelial growth involves the duplication of a ‘growth unit’ which consists of a tip and a certain mean length of hypha.
Abstract: Growth of Mucor hiemalis, Geotrichum candidum, Aspergillus nidulans, Neurospora crassa and Penicillium chrysogenum was studied by time lapse photography. The total hyphal length of the mycelium of each species increased at an exponential rate; in M. hiemalis exponential growth continued until the mycelium had a total hyphal length in excess of 10 mm. After spore germination there was an initial phase of discontinuous tip production followed by a phase of ‘continuous’ tip production. The hyphal length and number of tips possessed by a mycelium increased exponentially at approximately the same specific growth rate. The amplitude of the oscillations in the length of the hyphal growth unit of a mycelium decreased progressively during mycelial growth and eventually the growth unit attained a more or less constant value. The results support the hypothesis that mycelial growth involves the duplication of a ‘growth unit’ which consists of a tip and a certain mean length of hypha.
293 citations
TL;DR: It is concluded that the resulting monokaryotic mycelium is diploid, and isolated from basidiocarps of Armillariella mellea is dikaryotic.
Abstract: Dikaryotic hyphae isolated from basidiocarps ofArmillariella mellea are unstable in aseptic culture and change into monokaryotic hypae. During monokaryotization the nuclei of a dikaryon fuse and fusion nucleus immediately divides resulting in two uninucleate cells, from which the monokaryotic mycelium originates. Similar fusion of two nuclei takes place in matings of compatible singlespore isolates. It is concluded that the resulting monokaryotic mycelium is diploid.
65 citations
TL;DR: In this paper, mycolaminarans were isolated from zoospores and mycelium of Phytophthora palmivora and they are shown to have linear chains of (1→3)-linked β-D -glucose residues, with one or two branches joined by ( 1→6)-β-D linkages.
59 citations
TL;DR: The process of protoplast regeneration was studied both on solid and in liquid media, and 3 patterns were seen by which protoplasts could regenerate to normal mycelium.
Abstract: 1.
High yields of protoplasts from Penicillium chrysogenum Wisc. 49,2105 were obtained by using a combined enzyme system containing either Cellulase from Oxoporus plus an extract of Helix pomatia gut juice, or cellulase plus an enzyme preparation from the culture filtrate of Streptomyces graminofaciens ATCC 12,705. When 15 h old mycelium was incubated with one of these enzyme systems in 0.55 M NaCl at pH 5.6 nearly all of the mycelium was transformed into protoplasts within 4–5 h.
2.
The process of protoplast regeneration was studied both on solid and in liquid media. Approximately 50% of the protoplasts regenerated within 8–10 h. Addition of yeast extract to the medium accelerated the speed of regeneration. Microscopically, 3 patterns were seen by which protoplasts could regenerate to normal mycelium.
53 citations
TL;DR: The activity of the NADP-linked glutamate dehydrogenase (GDHNADP) increased in the pileus during sporophore development but remained at a low level in the parent mycelium and in the sporophores stipe, suggesting that the increase in GDHNAD activity is a developmental phenomenon.
Abstract: SUMMARY: The activity of the NADP-linked glutamate dehydrogenase (GDHNADP) increased in the pileus during sporophore development but remained at a low level in the parent mycelium and in the sporophore stipe. In contrast, the NAD-linked enzyme (GDHNAD) increased in mycelium, stipe and pileus. It is suggested that the increase in GDHNADP activity is a developmental phenomenon. In vegetative mycelia the two GDH enzymes appeared to be regulated reciprocally; GDHNAD was subject to catabolite repression and urea derepression, while GDHNADP was catabolite derepressed and repressed by urea. It is suggested that GDHNAD may be the enzyme normally involved in ammonia assimilation, GDHNADP being reserved for specific functions associated with developmental alterations in metabolism.
49 citations
TL;DR: Sporangia and oospores of P. cactorum persisted for appreciable periods in soil at temperatures and soil water contents likely to prevail during a growing season and could not be recovered from soil which had been allowed to dry.
Abstract: Sporangia and oospores of P. cactorum persisted for appreciable periods in soil at temperatures and soil water contents likely to prevail during a growing season.Mycelium lysed more rapidly as soil water content and temperature increased. Hyphae were not viable after 3 days incubation in wet soil at 29 °C but survived for at least 45 days at 4 °C.At soil water contents higher than 3.0 bars suction and at soil temperatures above 10 °C sporangia appeared on mycelium buried in soil. When soil moisture was reduced to 3.0 bars suction and temperature to 10 °C, oogonia were formed.Longevity of sporangia was reduced by increasing soil water content above 0.3 bars suction. Glucose added to soil induced germination of sporangia and germ tube elongation, while asparagine inhibited germination.Sporangia and oospores but not mycelium survived freezing temperatures in moist soil. Sporangia could not be recovered from soil which had been allowed to dry. Some oospores germinated after drying.
43 citations
TL;DR: The time at which mycelial development reached a peak and gave way to the production of budding yeast cells was directly proportional to the minimum doubling time of C. albicans in each medium.
Abstract: Five liquid media were tested for their ability to promote filamentation in Candida albicans. Three isolates, including one atypical variant, all developed mycelium in the early stages of growth. The proportion of mycelium produced was highest in the complex media with slightly alkaline pH values (7·5 to 8·6). The time at which mycelial development reached a peak and gave way to the production of budding yeast cells was directly proportional to the minimum doubling time of C. albicans in each medium. The principal effect of the medium was initially to induce filamentation in a greater or lesser number of blastospores.
41 citations
TL;DR: α-L-Arabinofuranosidase and acid p-nitrophenyl phosphatase were secreted by Sclerotinia fructigena grown in a liquid pectin/ammonium tartrate medium and some evidence was obtained for structure-linked latency of both enzymes and for their secretion by a process of reverse pinocytosis.
Abstract: α-L-Arabinofuranosidase (AF) and acid p-nitrophenyl phosphatase (AP) were secreted by Sclerotinia fructigena grown in a liquid pectin/ammonium tartrate medium. ‘Gentle’ mechanical manipulation of mycelium solubilized most of the AF and much of the AP, while brief acid treatment considerably inactivated both enzymes. Both enzymes were present predominantly in a soluble form in homo-genates prepared for subcellular fractionation, but some particulate activity of both was recovered from a sucrose density gradient in a fraction which also contained mitochondria. Azo-dye techniques with appropriate 1-naphthyl derivatives as substrates and p-(acetoxymercuric) aniline diazotate as capturing agent produced similar staining patterns for both enzymes in the light and electron microscopes, but the distribution of β-glycerophosphatase activity as visualized by the Gomori technique was more variable. A proportion of the activity of the enzymes remaining after fixation was located between the plasmalemma and the hyphal wall, in vacuoles in the cytoplasm, and in spherosome-like bodies. Some evidence was obtained for structure-linked latency of both enzymes and for their secretion by a process of reverse pinocytosis.
39 citations
Patent•
21 May 1974
TL;DR: Denatured protein is used as a nutrient supplement for the stimulation of the growth of mushroom mycelium as mentioned in this paper, and denatured proteins are mixed into the compost growing medium before or shortly after spawning.
Abstract: Denatured protein is used as a nutrient supplement for the stimulation of the growth of mushroom mycelium The denatured protein is admixed into the compost growing medium before or shortly after spawning A synergistic effect is attained by admixing a vegetable oil, or fish oil with the denatured protein
38 citations
TL;DR: Plant tissues of low C:N ratio decomposed in soil with the formation of volatiles which increased growth of R. solani in culture and induced pigmentation of its mycelium and melanin or a melaninlike pigment was formed in culture.
Abstract: Plant tissues of low C:N ratio decomposed in soil with the formation of volatiles which increased growth of R. solani in culture and induced pigmentation of its mycelium. The effective plant tissues included vegetable crop residues of C:N <15 and immature grain crop residues (corn, oat, rye,
37 citations
TL;DR: Analysis of neutral sugars derived by acid hydrolysis of insoluble residues showed an accumulation of a mannose-containing polymer in mycorrhizal roots, and the hypothesis that the endophyte derives a supply of carbohydrate from its host plant is discussed.
Abstract: The major soluble carbohydrates of mycorrhizal and non-mycorrhizal roots of the cultivated cranberry, Vaccinium macrocarpon Ait., have been identified and quantitatively analysed. Mycorrhizal roots contained two sugars, mannitol and trehalose, not found in uninfected roots. As these sugars are abundant in extracts of endophyte mycelium grown in liquid culture, they appear to be of fungal origin. Analysis of neutral sugars derived by acid hydrolysis of insoluble residues showed an accumulation of a mannose-containing polymer in mycorrhizal roots. Mannose was a principal component of insoluble polymers in the endophyte. All soluble carbohydrates in the root, including mannitol and trehalose, became labelled after feeding '4CO2 to the shoots. Sucrose was the most strongly labelled sugar in both types of root. M\'lannose present in hydrolysates of mycorrhizal roots was more heavily labelled than that derived from uninfected roots but most 14C in insoluble fractions was found in glucose polymers. The hypothesis that the endophyte derives a supply of carbohydrate from its host plant is discussed.
TL;DR: It appears that R. goodyerae-repentis does not freely utilize recent photosynthate from its host under the conditions of these experiments.
Abstract: SUMMARY
Uninfected plantlets of Goodyera repens and plantlets infected with the endophyte Rhizoctonia goodyerae-repentis were fed with 14CO2. Quantities of 14C fixed varied greatly between individuals, but there was a consistent pattern of distribution of label which remained unaltered over four weeks. Very little 14C moved to the rhizomes. The endophytic fungus readily grew from infected plantlets on to Pfeffer agar and small amounts of radioactivity were found in the mycelium growing from previously fed plantlets. 14C leakage from uninfected plantlets was negligible, although low levels of radioactivity occurred in serial washings from them. When the tops alone of infected plants were fed with 14CO2, no radioactivity could be detected in the emerging fungal mycelium. Where rhizomes alone were exposed, small quantities of 14C were detected in the growing mycelium. The fungus readily translocated 14C from the remains of dead protocorms. It appears that R. goodyerae-repentis does not freely utilize recent photosynthate from its host under the conditions of these experiments.
TL;DR: A significant portion of the repressible alkaline phosphatase produced by derepressed wild type N. crassa was found to be secreted into the growth medium and Electrophoresis at pH 4.7 and 9.5 indicated that the enzyme isolated from slime medium is more anionic than the enzyme from wild type mycelium.
Patent•
11 Oct 1974
TL;DR: Polysaccharides are produced by purifying a liquid extract of a mycelium of a strain of fungus species belonging to the class Basidiomycetes or the filtered broth of a cultured medium in which a mycellium of selected strain of Basidia has been incubated; the polysaccharide exhibiting an anticarcinogenic activity in mice as mentioned in this paper.
Abstract: Polysaccharides are produced by purifying a liquid extract of a mycelium of a strain of fungus species belonging to the class Basidiomycetes or the filtered broth of a cultured medium in which a mycelium of a selected strain of Basidiomycetes has been incubated; the polysaccharides exhibiting an anticarcinogenic activity in mice
TL;DR: Zoosporogenesis in the holocarpic marine phycomycete Lagenidium callinectes is initiated when actively growing mycelium is washed free of medium and placed in sea water as mentioned in this paper.
Abstract: Zoosporogenesis in the holocarpic marine phycomycete Lagenidium callinectes is initiated when actively growing mycelium is washed free of medium and placed in sea water. Portions of hyphae are wall...
TL;DR: Suppression of the glycolytic Krebs-cycle pathway and the stimulation of the pentose phosphate pathway seem important during the compaction and maturation of sclerotia.
Abstract: Succinate dehydrogenase (SDH) and glucose-6-phosphate dehydrogenase (Glu-6-PDH) from Sclerotinia sclerotiorum (Lib.) de Bary were moderately active in submerged mycelium while in non-sclerotial aerial mycelium arylesterase and acid phosphatase were very active. In sclerotial initials, glyceraldehyde-3-phosphate dehydrogenase (Gly-3-PDH) and SDH were at their highest level of activity, Glu-6-PDH and phosphogluconate dehydrogenase (PGDH) were moderately active, laccase activity increased markedly, and tyrosinase was detected for the first time, its activity being moderate. In young compacting sclerotia, the activities of Glu-6-PDH and PGDH increased, Gly-3-PDH and SDH showed lowered activities, and laccase activity decreased. Suppression of the glycolytic Krebs-cycle pathway and the stimulation of the pentose phosphate pathway seem important during the compaction and maturation of sclerotia. Tyrosinase may be involved in sclerotial initiation.
TL;DR: Anatomical studies on the infection biology of Scleroderris lagerberii (Brunchorstia pinea) and infection of Pinus nigra shoots by B. pinea were studied by means of both ordinary light and fluorescent microscopy.
Abstract: Anatomical studies on the infection biology of Scleroderris lagerberii (Brunchorstia pinea). Infection of Pinus nigra shoots by B. pinea was studied by means of both ordinary light and fluorescent microscopy. Following spore germination, the mycelium lives under and between the leaf scales, subsequently invading the leaf scales directly. The hyphae can grow through periderms, later invading the xylem via the rays.
TL;DR: The antibiotic exhibits antifungal effects also in vivo and is relatively little toxic for HeLa cells.
Abstract: Fusarium sp. S-435 produces a group of related antifungal antibiotics. Three components of a mixture were isolated in a pure state from the mycelium and cultivation medium of the productive strain: ramihyphins A, B and C. Another two components (D and E) were demonstrated by thin-layer chromatography. Ramihyphin A is the main component of the mixture. Its basic physical and chemical properties are presented. The antibiotic is not active against bacteria, yeast-like microorganisms, oomycetes and several protozoa. It inhibits the growth of higher filamentous fungi, stimulating ramification of hyphae when used at subfungistatic concentration. Ramihyphin A does not inhibit germination of conidia of sensitive fungi but stops their growth after their germination.Blastomyces dermatitidis, Coccidioides immitis andHistoplasma capsulatum belong to most sensitive pathogenic fungiin vitro. Ramihyphin A inhibits considerably the growth of the following phytopathogenic fungi:Stereum hirsutum, Neurospora sitophila, Botrytis cinerea, Monilia fructigena andAlternaria tenuis. The antibiotic exhibits antifungal effects alsoin vivo and is relatively little toxic for HeLa cells.
TL;DR: Significant amounts of aflatoxins were produced when mycelium of Aspergillus parasiticus NRRL3240 were grown for 4 days in a synthetic medium or a semi-synthetic medium, but not when resuspended in media lacking sucrose, or in buffers.
Abstract: SUMMARY: Considerable amounts of aflatoxins were produced when mycelium of Aspergillus parasiticus NRRL3240 grown for 4 days in a synthetic medium (SL medium) or a semi-synthetic medium (YES medium) were resuspended in either medium for 2 days, but not when resuspended in media lacking sucrose, or in buffers. Acetate[I-14C] was incorporated efficiently on addition to cultures grown in YES medium or on addition to mycelium grown and resuspended in SL medium. Changes in pH within the range of 3.5 to 6.5 did not have any pronounced effect on aflatoxin production or on incorporation of labelled acetate by resuspended mycelia.
TL;DR: The imperfect cellulolytic fungus Sporotrichum pulverulentum, which is commonly found growing in wood-chip piles, was grown in submerged culture on wheat shorts and other cereal flours, and the mycelial mass was easily harvested by filtration.
Abstract: The imperfect cellulolytic fungus Sporotrichum pulverulentum, which is commonly found growing in wood-chip piles, was grown in submerged culture on wheat shorts and other cereal flours. These substrates were broken down in 1 to 4 days at 30 to 40 C, and the mycelial mass was easily harvested by filtration. Scanning electron micrographs of hyphae in mycelial pellets are presented, and thin sections of conidia and hyphae were studied in a transmission electron microscope. Dolipores in septa of hyphae were observed, and cell walls are shown to be lamellar, which is characteristic of the Basidiomycetes. Actively growing hyphae are full of cytoplasm with numerous mitochondria, whereas old mycelial pellets contain highly vacuolated and almost empty cells. Images
TL;DR: The pattern of disease development discounts the possibility that ascospores are an important source of inoculum, and the primary inoculum in this disease is probably mycelium originating from sclerotia lying on the soil surface underneath the lower leaves.
Abstract: Lettuce varieties such as ‘Buttercrunch’, ‘Great Lakes’, and ‘Triumph’ which produced lower leaves that were in continual contact with the soil as they senesced were far more susceptible to infection by Sclerotinia minor than a variety, ‘Cos’, with an upright growth habit. The primary inoculum in this disease is probably mycelium originating from sclerotia lying on the soil surface underneath the lower leaves. The pattern of disease development discounts the possibility that ascospores are an important source of inoculum.
TL;DR: Schizophyllum commune from the mouth of a child has been used in a reappraisal of the developmental, morphological, and taxonomic position of the fungus.
Abstract: An isolate of Schizophyllum commune from the mouth of a child has been used in a reappraisal of the developmental, morphological and taxonomic position of the fungus. The fungus should be assigned to the Aphyllophorales. The presence of a coloured spore-print is discussed in the light of the discovery of a sheath around the basidiospore. The presence of tubercules on the vegetative mycelium can be used as a diagnostic character in the absence of fruiting-bodies.
TL;DR: The increase in free ergosterol per culture in the A-fraction was interrupted for 2 days at the time of protoperithecium formation, and there appeared to be a nett hydrolysis of ester at the onset of senescence.
TL;DR: High temperature caused breakdown of resistance in Psaknon, Turk, Hudson and West China, and the pathogenicity of one isolate (UWA307) was found to be impaired by high temperature.
Abstract: Germ tube growth and mycelium establishment of Rhynchospovium secali,~, the causal agent of scald in barley, were studied in seven resistant and four susceptible barley hosts of known genotype. Although no visible symptoms were apparent, none of the resistant hosts were free from mycelium establishment in leaf tissue. The resistant hosts could be divided into two categories according to the rate of germ tube growth. The effect of host age, duration of incubation period, temperature, spore concentration, and pathogen age on symptom expression in the 11 genotypes was examined. Excluding the effects of temperature, the resistant genotypes could be grouped into (a) those expressing their resistance consistently, e.g. Psaknon, Atlas 46, Atlas 57, Hudson and Turk, and (b) those expressing their resistance inconsistently, e.g. West China and La Mesita. High temperature caused breakdown of resistance in Psaknon, Turk, Hudson and West China. The pathogenicity of one isolate (UWA307) was found to be impaired by high temperature. Implications of the above findings are discussed in relation to the disease situation in Western Australia.
TL;DR: The results seem to indicate this might be due to the lack of a specific diketopiperazine transport system, because there was no uptake of Leu-Pro-lactam by these particular strains derived from grass-ergot.
TL;DR: Etching pattern of vacuole changed considerably depending on the growth phase of the organism, and Vacuole of mycelial cell had depressions in membrane whereas that of arthrospore did not.
Abstract: Mycelial cells and arthrospores of Mucor were observed by freeze-etching. The cell membrane of mycelial cell appeared relatively smooth and did not possess any of the usual rod-like invaginations. In some cells the inner surface showed protrusions of microfibrillar appearance and the nucleus had an irregular shape and prominent protuberances. Some nuclei were interconnected with the protuberance. Vesicles (50–100 nm) and tubular structures (50 by 200–400 nm) were abundant. Lipid droplets were not developed. Mitochondria of mycelial cells were generally cross-fractured, revealing cristae running paralled to the longer axis. Features of rectangular arthiospore resembled those of mycelial cells except for the abundance of vesicles. Mature arthrospore became enlarged and spherical and many round depressions about 50 nm in size were seen in cell membrane. Vacuole of mycelial cell had depressions in membrane whereas that of arthrospore did not. Etching pattern of vacuole changed considerably depending on the growth phase of the organism.
TL;DR: The ability of chlamydospores to germinate at low water potentials is discussed in relation to a field situation and the presence of root rot in samower crops growing in dry soils.
Abstract: Chlamydospores of Phytophthora drechsleri Tucker germinated readily on solute-amended agars with potentials as low as — 98·5 bar, whereas mycelium from mycelia inocula failed to grow at potentials lower than — 56 bar. Formation of cross walls within germ tubes was common but subsequent growth was not affected. During germination the spore wall often split and separated from the protoplast. No swelling prior to germination was evident. The ability of chlamydospores to germinate at low water potentials is discussed in relation to a field situation and the presence of root rot in samower crops growing in dry soils.
TL;DR: Water-soluble glycoprotein, which accounted for approximately 3 to 3.5% of either the spore coat or mycelial wall dry weight, was of similar amino acid composition from both sources and did not decrease in protein content upon spore germination.
Abstract: Ethylenediamine-soluble glycoproteins were extracted from isolated Microsporum gypseum hyphal walls during sporulation and from spore coats before and after germination. This study was carried out to identify a sporulation-specific cell wall protein that possibly served as a substrate for the alkaline protease which initiated the macroconidial germination of this fungus. Analyses revealed that water-insoluble glycoprotein accounted for 10% of the ungerminated spore coat but only for 4 to 5% of the mycelial wall dry weight. This fraction was modified in its amino acid composition during sporulation, and it decreased in protein content during spore germination. Water-soluble glycoprotein, which accounted for approximately 3 to 3.5% of either the spore coat or mycelial wall dry weight, was of similar amino acid composition from both sources and did not decrease in protein content upon spore germination. The water-insoluble glycoprotein was found to be rich in leucine, aspartic acid, glycine, glutamic acid, and phenylalanine residues. The water-soluble glycoprotein was rich in proline, threonine, glycine, serine, glutamic acid, and alanine.
TL;DR: A spore to spore study of the marine biflagellate fungus Lagenidium callinectes was made correlating light and electron microscopic observations, which revealed the internal structure of the hyphae.
Abstract: A spore to spore study of the marine biflagellate fungus Lagenidium callinectes was made correlating light and electron microscopic observations. The study first compared the vegetative morphology of both young and mature hyphae. Germination is by direct hyphal outgrowth of an encysted zoospore. The young mycelium is irregular in width, densely packed with cytoplasm, and has few septations. With age, vacuoles become more prominent, confining the cytoplasm in the periphery of the hyphae. The electron microscope revealed in more detail the internal structure of the hyphae.
TL;DR: Polar lipid components of the mycelia, conidia and sclerotia of the cotton root rot fungus, Phymatotrichum omnivorum, were analysed and the most abundant unsaturated fatty acids were Jinoleic and oleic, whereas the predominant saturated fatty acid was palmitic.
Abstract: Polar lipid components of the mycelia, conidia and sclerotia of the cotton root rot fungus, Phymatotrichum omnivorum, were analysed. The major phosphatides in mycelia, conidia and sclerotia were phosphatidyl choline, phosphatidyl ethanolamine and lysophosphatidyl choline. Phosphatidyl serine was found only in mycelia and sclerotia. In the mycelia, conidia and sclerotia, the most abundant unsaturated fatty acids were Jinoleic and oleic, whereas the predominant saturated fatty acid was palmitic. Hyphae, sclerotia, and conidia contained relatively small lipid bodies and some conidia also contained prominent lipid bodies. Hyphae also contained spherosome-like organelles.