Copper and cobalt alter the cell wall composition of Cunninghamella blakesleeana

Cunninghamella blakesleeana was highly sensitive to Cu and Co on a medium containing NaNO3 as the sole nitrogen source. The nitrate reductive pathway was altered by Cu and Co, and NO-2 accumulated in the medium. Under conditions of Cu toxicity, the mycelium and the cell walls acquired a blue color, and most of the Cu was located in the cell walls, which differed in several aspects from cell walls derived from Co-containing or control cultures. At half-maximal growth inhibition by Cu (2.5 micrograms/mL or 39.3 microM) or Co (3.5 micrograms/mL or 59.4 microM), the mycelia contained 1.5 micrograms Cu or 1.0 microgram Co/mg dry tissue, respectively, but the isolated cell walls contained 33.5 micrograms Cu or 1.8 micrograms Co/mg dry cell wall. The phosphorous content of mycelia from Co-containing cultures was the same as that from control cultures, whereas that of mycelia from Cu-containing cultures contained 36% less. However, the phosphorous content of the cell walls from mycelia cultured in the presence of Cu or Co was two- and three-fold higher, respectively, than that of cell walls from control cultures. The cell walls of Cu-containing cultures contained significantly less hexosamine than the control cell walls, and chitin and chitosan were present in equal quantities. The cell walls of Co-containing cultures had the same amount of hexosamine as the control cell walls, but 88% of the hexosamine was present as chitosan and bound very little Co. The control cell walls contained approximately 60% chitosan.(ABSTRACT TRUNCATED AT 250 WORDS)     

Transformation of verapamil by Cunninghamella blakesleeana

A filamentous fungus, Cunninghamella blakesleeana AS 3.153, was used as a microbial model of mammalian metabolism to transform verapamil, a calcium channel antagonist. The metabolites of verapamil were separated and assayed by the liquid chromatography-ion trap mass spectrometry method. After 96 h of incubation, nearly 93% of the original drug was metabolized to 23 metabolites. Five major metabolites were isolated by semipreparative high-performance liquid chromatography and were identified by proton nuclear magnetic resonance and electrospray mass spectrometry. Other metabolites were characterized according to their chromatographic behavior and mass spectral data. The major metabolic pathways of verapamil transformation by the fungus were N dealkylation, O demethylation, and sulfate conjugation. The phase I metabolites of verapamil (introduction of a functional group) by C. blakesleeana paralleled those in mammals; therefore, C. blakesleeana could be a useful tool for generating the mammalian phase I metabolites of verapamil.     

Transformation of Verapamil by Cunninghamella blakesleeana

A filamentous fungus, Cunninghamella blakesleeana AS 3.153, was used as a microbial model of mammalian metabolism to transform verapamil, a calcium channel antagonist. The metabolites of verapamil were separated and assayed by the liquid chromatography-ion trap mass spectrometry method. After 96 h of incubation, nearly 93% of the original drug was metabolized to 23 metabolites. Five major metabolites were isolated by semipreparative high-performance liquid chromatography and were identified by proton nuclear magnetic resonance and electrospray mass spectrometry. Other metabolites were characterized according to their chromatographic behavior and mass spectral data. The major metabolic pathways of verapamil transformation by the fungus were N dealkylation, O demethylation, and sulfate conjugation. The phase I metabolites of verapamil (introduction of a functional group) by C. blakesleeana paralleled those in mammals; therefore, C. blakesleeana could be a useful tool for generating the mammalian phase I metabolites of verapamil.     

Hydroxylation of progesterone by Cunninghamella blakesleeana NCIM 687

Progesterone was completely hydroxylated, principally to 11,14 dihydroxyprogesterone by Cunninghamella blakesleeana NCIM 687 in 48h.S.B. Chincholkar is with the Microbiology Division, Department of Life Sciences, North Maharashtra University, Jalgaon 425 001, India. R. Seeta Laxman is with the Division of Biochemical Sciences, National Chemical Laboratory, Pune 411 008, India. R.D. Wakharkar is with Organic Chemistry. Technology Division, National Chemical Laboratory, Pune 411 008. India     

Biotransformation of albendazole by Cunninghamella blakesleeana: effect of carbon and nitrogen source

A filamentous fungus Cunninghamella blakesleeana was screened for its ability to biotransform the anthelmintic drug albendazole. The fungus produced three metabolites in the presence of the carbon and nitrogen sources studied. The transformation was identified by HPLC and the structures of the transformation products were assigned by LC-MS-MS analysis and on the basis of previous reports. The results indicated that the fungus metabolized albendazole into albendazole sulfoxide (M1), albendazole sulfone (M2) and an N-methyl metabolite of albendazole sulfoxide (M3). The effect of carbon and nitrogen source on the biotransformation of albendazole was significant. Among the carbon and nitrogen sources studied, fructose and urea respectively produced maximum extent of biotransformation in terms of substrate depletion. Among the carbon sources studied, maltose produced a higher percentage of M1 whereas M2 and M3 were produced to their maximum extent in presence of d-fructose in terms of metabolite per unit quantity of biomass. In the case of nitrogen sources, ammonium acetate, calcium nitrate and barium nitrate produced maximum percentage of M1, M2 and M3 respectively. The results reveal that the carbon and nitrogen source significantly influence the microbial transformation both qualitatively and quantitatively.     

Morphological changes induced by ampicillin in Campylobacter

Morphologic changes in Campylobacter fetus ssp. jejuni were evaluated as cultivated on thioglycollute broth, containing minimum of 0.1, 1.3 and 10 Ampicillin minimal inhibitory concentration (MIC). During the first four hours of incubation, no changes occurred in the presence of 0.1 MIC; but with the rest of the ampicillin doses, even at the first hour, a proportion larger than 5% of filament-policurved forms was found, and it increased with the incubation time. The greatest number of altered bacteria was found with the use of 10 MIC. No other morphologic changes were observed.     

Morphological changes induced in fungi by antibiotics

In tests of 31 antibiotics, 29 inhibited growth ofBotrytis cinerea and of these, 18 induced morphological changes. Terminal and lateral branching of the hyphae was induced by actinomycin D, aspergillic acid, citrinin, cyanein, cycloheximide, desertomycin and polyene antibiotics. Curling of the hyphae was induced by griseofulvin and narrowing of the hyphae by citrinin. Some antibiotics at different concentrations produced several types of morphological changes. For example, aspergillic acid, desertomycin and flavofungin also induced terminal bulging of the hyphae. Growth of the dimorphic fungusPaecilomyces viridis was inhibited by 24 antibioties, nine of which induced morphological changes. Branching of the hyphae was induced by azalomycin F, citrinin, eyanein, desertomycin, patulin, rugulosin and trichothecin. Griseofulvin had a curling effect. Except for rugulosin, the above antibiotics, in higher concentrations, induced yeast-like growth ofPaecilomyces viridis. Morphological changes were also induced by inhibitors of RNA and protein synthesis and by antibiotics injuring the cell membranes. Antibiotics with different mechanisms of action induced similar morphological changes.     

Microbial Transformations of Natural Antitumor Agents: Products of Rotenone and Dihydrorotenone Transformation by Cunninghamella blakesleeana

[This corrects the article on p. 617 in vol. 45.].     

Microbial Transformations of Natural Antitumor Agents: Products of Rotenone and Dihydrorotenone Transformation by Cunninghamella blakesleeana

Various species of Absidia, Aspergillus, Cunninghamella, Trichothecium, Penicillium, and Phanerochaete were found to transform rotenone to one or more metabolites. Two biotransformation products were isolated from a preparative-scale incubation of rotenone with Cunninghamella blakesleeana and identified as 1′,2′-dihydro-1′,2′-dihydroxyrotenone and 3′-hydroxyrotenone (amorphigenin). The catalytic reduction of the isopropylene side chain of rotenone resulted in the formation of 1′,2′-dihydrorotenone. The latter was transformed by C. blakesleeana to 2′-hydroxy-1′,2′-dihydrorotenone.     

Morphological, histological and ultrastructural changes in the olive pistil during flowering

Sexual reproduction is essential for the propagation of higher plants. From an agronomical point of view, this is a particularly key process because fertilization guarantees fruit formation in most cultivated fruit species. In the olive, however, in spite of its agricultural importance, little attention has been paid to the study of sexual reproduction. In order to investigate the cellular and molecular mechanisms that regulate pollen-pistil interactions in the olive during the progamic phase, it is essential to first have a good knowledge of the reproductive structures involved in such interactions. This study characterizes the anatomical and ultrastructural changes in the olive pistil, beginning from the young pistil developing within the bud until the time of petal loss and visible stigma senescence. We have correlated changes in the pistil with a series of defined floral developmental stages and determined that olive pistil structures cannot be considered completely mature and ready to be pollinated and fertilized until the onset of anthesis. Our results clearly show histological and ultrastructural variation during the diverse flowering events. We discuss whether the changes observed might influence or result from pollen-pistil interactions during the progamic phase.     

Morphological changes in asymmetric erythrocyte membranes induced by electrolytes

Washed human erythrocyte membranes are made permanently leaky to cations by EDTA. These ghosts can exhibit the stomatocyte-disc-echinocyte sequence of shape changes in response to electrolytes in the medium. The changes are instantaneous and reversible. The observations can be explained on the basis of the known effects of cations on charged phospholipids together with the bilayer couple hypothesis.     

Morphological changes in mice thyroid induced by iodine deficiency

Goitrogenesis induced in mice by iodine deficiency took place in two distinct phases. The first phase lasted four weeks and was characterized histologically by the classic signs of hyperplasia: colloid resorption, increase in the height of the epithelium and enlargment of the capillaries. After the fourth week, the morphological changes in the thyroid were different in males and females. In the male, pluristratified follicles, secondary follicular cavities and papillary projections were observed. In the female, most of the follicles retained their hyperplastic appearance, while papillary projections were observed in very few follicles.     

Morphological, immunohistochemical and ultrastructural changes in dimethylnitrosamine [correction of dimenthylnitrosamine] induced liver injury. Effect of malotilate

Dimethylnitrosamine (DMN) induced liver injury in rats with cell necrosis, inflammation, hemorrhages, increased collagen type III synthesis and basement membrane component laminin and collagen IV localization in perisinusoidal sites. Malotilate ingestion during DMN treatment abolished inflammation and decreased interstitial collagen deposits and vascularization. It affected clearly less DMN-caused hemorrhage. When malotilate treatment was started subsequently to development of DMN-injury, it also caused decrease in inflammation, though less, as well as in collagen III, BM and fibronectin deposits. We suggest that the mode of the malotilate effect on reducing the DMN-induced fibrosis of the liver is via inhibiting the inflammation, decreased fibronectin deposition possibly also playing a role.     

Morphological and ultrastructural changes induced by sublethal concentrations of an anionic detergent on Ictalurus species barbel taste buds.

Morphological and ultrastructural changes were studied in Ictalurus sp. barbel taste buds (TBs), exposed to sublethal concentrations (3 ppm) of sodium alkylbenzene sulphonate for periods varying from 3 to 15 days. No significant alterations were noted after 3 days while, after just 6 days damage began to appear. The blood vessels were dilated and larger, more numerous intercellular spaces were observed between the light and dark TB cells than were to be found in the controls, but the basal portion of the TB was unaltered. After 9-12 days the most prominent features were the rupture of the plasma membranes, loss of microvillar organization of the light and dark cells as well as an increase in cytoplasmatic vacuolization. The skin was damaged and the germinative layer of the epidermis appeared activated and its height had increased. About 30% of the TBs were affected, and after 15 days they were severely damaged, whilst the feeding behaviour changed from day 6 onwards.     

Morphophysiological,ultrastructural, and nutritional changes induced by Cu toxicity in young Erythrina fusca plants

Erythrina fusca is an important legume used for shade cover in cacao plantations in Brazil. Cacao plantations receive large quantities of copper (Cu)-containing agrochemicals, mainly for control of diseases. Therefore, Cu toxicity was investigated in seedlings grown in hydroponics with increasing concentrations of Cu (0.005–32 mg L^?1) in a greenhouse. Ultrastructural analyses showed cell plasmolysis in the root cortical area and changes in thylakoid membranes at 8 mg Cu L^?1 and higher. There were changes in epicuticular wax deposition on the leaf surface at the 16 and 32 mg Cu L^?1 treatments. Leaf gas exchanges were highly affected 24 hours after application of treatments beginning at 8 mg Cu L^?1 and higher Cu concentrations. Chemical analyses showed that Cu content in E. fusca roots increased as Cu concentration in the nutrient solution increased, whereas the shoot did not show significant changes. It is also observed that excess Cu interfered with Zn, Fe, Mn, Mg, K, P, and Ca content in the different E. fusca organs. Investigation of Cu toxicity symptoms focusing on morphophysiological, ultrastructural, gas exchange, and nutritional changes would be useful to alleviate Cu toxicity in E. fusca under field conditions, an important agroforestry species in cacao plantation.