The ultrastructure of Penicillium chrysogenum in the course of benzyl-penicillin biosynthesis

KURYŁOWICZ, WŁODZIMIERZ; Kurzątkowski, W; Woznicka, W; Połowniak-Pracka, Hanna; Paszkiewicz, A

doi:10.1016/s0323-6056(79)80031-2

Cited by 11 publications

(11 citation statements)

References 12 publications

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“…Chemical fixation, which is one of the steps of this procedure, affects the overall structure of the plasma membrane, as shown by freeze-fracture experiments. The lamellar membranous structures and the cisternae in vacuoles, as found by Kurylowicz et al (1980) in P. chrysogenum using the classical ultrathin sectioning technique, might therefore be an artefact. Using cryofixation and freeze-substitution, we did not find this kind of structure.…”

Section: Discussionmentioning

confidence: 98%

“…Most information about ultrastructural features of commercial fungi has been obtained by using specimens prepared with the classical ultrathin sectioning technique. In this method the fungal material is chemically fixed, dehydrated in an organic solvent at room temperature, embedded in an epoxy resin, heat polymerized and subsequently ultrathin sectioned (Collinge et al, 1978;Kurylowicz et al, 1980;Scott et al, 1986). It has been shown that this preparation procedure causes structural alterations, since chemical fixation is slow (Knoll et al, 1987) and dehydration at room temperature introduces shrinkage of the overall structure of the cell (Boyde, 1980) as well as lipid extraction (Cope & Williams, 1968).…”

Section: Introductionmentioning

confidence: 99%

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A preparation method of specimens of the fungus Penicillium chrysogenum for ultrastructural and immuno‐electron microscopical studies

Müller

Krift

Knoll

et al. 1991

Journal of Microscopy

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A combination of cryofixation without pre-treatment, freeze-substitution and lowtemperature embedding was used to prepare specimens of Penicillium chrysogenum for electron microscopy. To produce specimens which are thin enough for appropriate cryofixation, the P . chrysogenum colonies were grown between dissected-dialysis tubing on an agar plate, which in addition allowed longitudinal sectioning. In contrast to classical chemical fixation, this preparation procedure resulted in excellent preservation of ultrastructure. Furthermore, the penicillin biosynthetic enzyme acyltransferase could be unequivocally located by immunogold labelling, indicating a preservation of antigenic properties of the specimen. Labelling density was not conspicuously affected when using different freeze-substitution media, but it was reduced after embedding in Epon 812.

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Section: Discussionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

A preparation method of specimens of the fungus Penicillium chrysogenum for ultrastructural and immuno‐electron microscopical studies

Müller

Krift

Knoll

et al. 1991

Journal of Microscopy

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“…Preparation for the transmission electron microscopy was performed as previously described 6 with the exception of the fixation time which was conducted in 4% glutaraldehyde (Sigma‐Aldrich, Milwaukee, WI, USA) for 5 h at 5 °C and then continued with 1% osmium tetroxide (Fluka) solution for 2 h. The samples were dehydrated in increasing concentrations of ethyl alcohol and embedded in Epon 812 (Serva‐Electrophoresis, Heidelberg, Germany) at room temperature. The blocs were polymerised at 37 °C for 24 h and at 64 °C for 48 h, and cut on LKB III Ultra Microtome (Diversified Equipment, Inc., Lorton, VA, USA).…”

Section: Methodsmentioning

confidence: 99%

Damage of Candida albicans blastoconidia exposed to biocides

Kurzaątkowski

Staniszewska

Tyski

2011

Mycoses

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The damage of Candida albicans blastoconidia exposed to the lowest concentration of chemical disinfectant and antiseptic passing the EN 1275:2005 at 5 min contact time was examined under transmission electron microscopy and scanning electron microscopy. The blastoconidia of C. albicans 82 exposed to the chemical products showed the following damage: Incidin Liquid Spray (disinfectant) and Spitaderm (antiseptic) - cytoplasm congealing; Incidin Plus and Lysoformine 3000 (disinfectants) - cell wall and cell membrane damage, and leakage of the cytoplasm; Medicarine (disinfectant) - cytoplasm denaturation and rough cytoplasm. The damage of blastoconidia of the strains C. albicans 24 and C. albicans 28, exhibiting different susceptibility to Lysoformine 3000 was compared under scanning electron microscopy. The blastoconidia of the strain C. albicans 28 did not exhibit essential damage at a concentration 16 times lower (0.02%) than the lowest concentration of Lysoformine 3000 (Lc-LYS) for this strain (0.32%). At this concentration (0.02%, corresponding to Lc-LYS for C. albicans 24) the more sensitive isolate 24 showed substantial damage. The conducted study exhibited the effects of the tested products against the viability and structural integrity of the cells. Blastoconidial buds at the early stage of development seem to be very susceptible to the action of the tested products. The budding areas are located mainly at the blastoconidial poles.

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“…Strains were cultivated on sporulation medium S (Kurylowicz et al 1980) containing (grams per litre) glycerol, 6; molasses, 7.5; yeast extract, 5 (Difco, Detroit, Mich., USA); NaC1, 10; MgSO4-7H~O, 0.05; KH2PO4, 0.05; CaSO4, 0.25; (NH4)Fe(SO4)2, 0.002; agar, 25, at pH 6.4-6.6, on slants for 10 days at 25°C in the dark. Segregants were obtained by transferring conidial populations from slant to slant over six generations (passages).…”

Section: Methodsmentioning

confidence: 99%

Genetic instability of industrial strains of Penicillium chrysogenum

Künkel¹,

Berger²,

Risch³

et al. 1992

Appl Microbiol Biotechnol

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It has shown that several characteristics of high-producing industrial strains of Penicillium chrysogenum tend to segregate in the course of cultivation (slant-to-slant transfer). Segregation includes a decrease in the yield of penicillin, mean conidial size, mean size of the nuclei, and an increase in the proportion of morphologically wild-type colonies. These lower-producing segregants also have a higher sensitivity against ultraviolet radiation and, as shown by cytofluorometric methods, a lower DNA content in the conidia, a decrease in phosphate uptake and in the activity of extracellular alkaline phosphatases compared to high-producing strains. Obviously, during mutagenesis/selection programmes ploidy mutants have been selected, which entails an increase in the number of genes coding enzymes responsible for penicillin biosynthesis. In the absence of selection pressure these high-producing strains segregate to lower-producing strains by chromosome losses in the course of slant-to-slant transfers.

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The ultrastructure of Penicillium chrysogenum in the course of benzyl-penicillin biosynthesis

Cited by 11 publications

References 12 publications

A preparation method of specimens of the fungus Penicillium chrysogenum for ultrastructural and immuno‐electron microscopical studies

A preparation method of specimens of the fungus Penicillium chrysogenum for ultrastructural and immuno‐electron microscopical studies

Damage of Candida albicans blastoconidia exposed to biocides

Genetic instability of industrial strains of Penicillium chrysogenum

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