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  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 42 (1995), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: . Seabottom sediments from a discontinued Philadelphia-Camden 40-Mile ocean sewage disposal site were cultured for cyst-forming free-living amoebae. Barge delivered wastes were discharged at the site from 1973 until 1980 when the site was closed. One station at the southeast margin of the site was sampled at a depth of approximately 50 m, twice in 1978 and once in 1982, 1983 and 1984. Sediment from the 1978 collection yielded Acanthamoeba polyphaga, Vahlkampfia sp., and an unknown amoeba with stellate endocysts similar to those of A. astronyxis. Trophozoites and cysts of the isolate were typical of those described for the genus Acanthamoeba. Biochemical tests employing enzyme electrophoresis and morphological studies on live and stained specimens showed that the isolate was distinct from other well-described species within the family Acanthamoebidae Sawyer & Griffin, 1975.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Naegleria fowleri cells, grown axenically, contain high levels of β-D-glucosidase which catalyzes the hydrolysis of 4-methylumbelliferyl-β-D-glucopyranoside (4MUGlc) (Km, 0.9 mM), octyl-β-D-glucoside (Km, 0.17 mM), and p-nitrophenyl-β-D-glucopyranoside at relative rates of 1.00, 2.88, and 1.16, respectively (substrate concentration, 3.0 mM). When the amebae are subjected to freeze-thawing, sonication, and centrifugation (100,000 g, 1 h), 85% of the β-glucosidase activity appears in the supernatant fraction. The β-glucosidase was purified 40-fold (34% yield) using a combination of chromatographic steps involving DE-52 cellulose, concanavalin A-Sepharose, and hydroxylapatite followed by isoelectric focusing. The predominant soluble β-D-galactosidase activity in the Naegleria extract copurifies with the β-D-glucosidase; the two activities have the same isoelectric point (pI, 6.9), similar heat stabilities, are both inhibited by lactobionic acid (Ki, 0.40 mM), and exhibit optima at pH 4.5, indicating that they are probably the same enzyme. The Naegleriaβ-D-glucosidase has an apparent molecular weight of 66,000, a Stokes radius of 25 Å, and a sedimentation coefficient of 4.2S. The β-glucosidase is not inhibited by conduritol β-epoxide or galactosylsphingosine but is completely inhibited by 1.25 mM bromo conduritol β-epoxide. The latter compound, when present in the growth medium, inhibits the growth of the organism and profoundly alters its ultrastructure, the main effect being the apparent inhibition of cytokinesis and the generation of multinucleate cells. The issue of the role of the β-glucosidase in the metabolism of the ameba and its possible role in pathogenic mechanisms are discussed.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: . Extracts of the pathogenic ameba Naegleria fowleri, prepared by freeze-thawing and sonication, were analyzed for their content of various hydrolytic enzymes that have acid pH optima. The organism is rich in acid phosphatase activity as well as a variety of glycosidases which include β-glucosidase, β-galactosidase, β-fucosidase, α-mannosidase, hexosaminidase, arylsulfatase A, and β-glucuronidase. The crude extract contained only negligible levels of sphingomyelinase, neuraminidase, or arylsulfatase B. All of the hydrolases exhibited higher activity at pH 5.5 than at 7.0, indicating that they are truly “acid” hydrolases. In general, after centrifugation (100,000 g, 1 h), except for arylsulfatase B, more than half of the activity of each of the various hydrolases was recovered in the supernatant fraction. The acid phosphatase in the high-speed supernatant was purified 45-fold (32% yield) by chromatography on QAE-Sephadex and Sephadex G-200 and shown to have the following properties: 1) pH optima, 5.5; 2) Km (4-methylumbelliferyl phosphate), 0.60 mM; 3) molecular weight (estimated by gel filtration chromatography), 92,000; 4) inhibited by heteropolymolybdate complexes but not by L(+) sodium tartrate (0.5 mM) or sodium fluoride (0.5 mM). In addition, unlike the tartrate-resistant acid phosphatase of Leishmania donovani, the major acid phosphatase of N. fowleri is less than 5% as effective in inhibiting superoxide anion production by f-Met-Leu-Phe-stimulated human neutrophils. The finding of high levels of a number of acid hydrolases in Naegleria fowleri raises several questions that merit further study: Do the hydrolases perform a housekeeping function in this single cell eukaryote or do they play some role in the pathogenic process that ensues when the organism infects a suitable host?
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 25 (1978), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS Enhanced esterase C activity could be demonstrated by starch gel electrophoresis in various stocks of Paramecium spp. (P. primaurelia stocks 90 and 540, P. biaurelia stock 93, P. tetraurelia stock 29. P. pentaurelia stock 87, P. octaurelia stocks 31 and 300, and P. multimicronucleatum species 3, stock 8 MO) grown in Adaptation Medium. This esterase, however, was barely detectable when they were cultivated in Axenic Medium. Addition of trypticase to Adaptation Medium resulted in reduction of esterase C in the ciliates. This effect is ascribable to Na acetate present in trypticase. Since esterase C increased with the decrease in acetate concentration (as estimated by gas-liquid chromatography) during growth of Paramecium, acetate appears to be utilized by the cells. Sensitivity of esterase C to acetate occurs in all 6 species of Paramecium examined. Different stocks within a species may have different levels of sensitivity; in one case this is genetically determined. The results emphasize the importance of controlling and manipulating growth conditions for the assessment of inter- and intraspecies variations in the isozymes of Paramecium.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 42 (1995), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: . A new diplomonad flagellate, Spironucleus vortens n. sp., is described from the intestinal lumen of the freshwater angelfish, (Pterophyllum scalare), bred in Florida. Live organisms are pyriform, and measure 12.5–20.5 μm long by 5.0–11.2 üm wide. Scanning electron microscopy shows that the trophozoite bears two compound lateral longitudinal ridges, each originating posterior to three emerging anterior flagella, and continuing posteriorly to the emergence of the posterior flagellum. Each ridge comprises a broad central part, surrounded by a peripheral ridge. At the opening of the flagellar pocket, the broader right peripheral ridge crosses to the other side of the body, and then back again. The posterior end of the body bears two papillae. Transmission electron microscopy shows that the compound lateral ridges are supported by microtubules, and bear microfibrillar structures in discrete longitudinal plaques. The serendipitous growth of S. vortens in a culture system with lip tumor tissue, facilitated axenic cultivation in a modified TYM medium (trypticase, yeast extract, maltose). The flagellate is now routinely maintained in an axenic TYI-S-33 medium (trypticase, yeast extract, iron serum), and is stabilized in the cryopreserved state. Spironucleus vortens is an aerotolerant anaerobe that can be cultured at 25° C, 28° C and 30° C.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: . Small subunit (16S-like) ribosomal RNA sequences were obtained from representatives of all four families constituting the order Trichomonadida. Comparative sequence analysis revealed that the Trichomonadida are a monophyletic lineage and a deep branch of the eukaryotic tree. Relative to other early divergent eukaryotic assemblages the branching pattern within the Trichomonadida is very shallow. This pattern suggests the Trichomonadida radiated recently, perhaps in conjunction with their animal hosts. From a morphological perspective the Devescovinidae and Calonymphidae are considered more derived than the Monocercomonadidae and Trichomonadidae. Molecular trees inferred by distance, parsimony and likelihood techniques consistently show the Devescovinidae and Calonymphidae are the earliest diverging lineages within the Trichomonadida, however bootstrap values do not strongly support a particular branching order. In an analysis of all known 16S-like ribosomal RNA sequences, the Trichomonadida share most recent common ancestry with unidentified protists from the hindgut of the termite Reticulitermes flavipes. The position of two putative free-living trichomonads in the tree is indicative of derivation from symbionts rather than direct descent from some free-living ancestral trichomonad.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: . A free-living amoeba identified as Hartmannella vermiformis was isolated from a water sample obtained during an investigation of nosocomial legionellosis. Hartmannella vermiformis is known to support the intracellular multiplication of Legionella pneumophila. This strain of H. vermiformis, designated CDC-19, was cloned and established in axenic culture to develop a model for the study of the pathogenicity of legionellae. Isoenzyme patterns of axenically-cultivated strain CDC-19 were compared with two strains of H. vermiformis derived from the type strain, one axenic (ATCC 50236) and the other grown in the presence of bacteria (ATCC 30966). Enzyme patterns suggested that all three strains are assignable to the species H. vermiformis. Axenic H. vermiformis strain CDC-19 has been deposited with the American Type Culture Collection (ATCC 50237) and should prove useful in the study of protozoan-bacterial interaction.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 30 (1983), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Chemically defined minimal media for the cultivation of high temperature tolerant and pathogenic Naegleria spp. have been developed. A defined minimal medium, identical for N. fowleri and N. lovaniensis, consists of eleven amino acids (arginine, glycine, histidine, isoleucine, leucine, methionine, phenylalanine, proline, threonine, tryptophan, and valine), six vitamins (biotin, folic acid, hemin, pyridoxal, riboflavin, and thiamine), guanosine, glucose, salts, and metals. Three of the four strains of Naegleria fowleri tested (ATCCr̀30100, ATCCr̀30863, and ATCCr̀30896) and two strains of N. lovaniensis (ATCCr̀30467 and ATCCr̀30569) could be cultured beyond ten subcultures on this medium. For N. fowleri ATCCr̀30894 diaminopimelic acid, or lysine, or glutamic acid was also required. Mean generation time was reduced and population density increased for all strains with the introduction of glutamic acid. Glucose could be eliminated from the minimal medium only if glutamic acid was present. Without glucose, mean generation time increased and population density decreased. Diaminopimelic acid could substitute for lysine for ATCCr̀30894, indicating that Naegleria species may synthesize their lysine via the DAP pathway. Naegleria fowleri ATCCr̀30100 could be adapted to grow without serine or glycine in the minimal medium with glutamic acid added, but with mean generation time increased and population density decreased. The strain could be grown in the minimal medium in the absence of metals. For growth of N. australiensis ATCCr̀30958, modification of the medium by increasing metals ten-fold, substituting guanine for guanosine and adding lysine, glutamic acid, and six vitamins (p-aminobenzoic acid, choline chloride, inositol, vitamin B12, nicotinamide, and Ca pantothenate) was required.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 30 (1983), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: . One hundred eighty-eight stocks of Paramecium primaurelia. P. biaurelia, P. tetraurelia. and P. octaurelia were grown axenically and screened for variation in four different esterases and acid phosphatase using starch gel electrophoresis. Major observations: frequency of intraspecies variation for these enzymes is much lower in these four species than in other organisms; hypervariability for two esterases occurs in P. biaurelia both in isolates from worldwide locales and in a restricted locale; clustering of variations occurs in a high proportion of variant stocks in all four species; frequency of intraspecies variation is highest in Central and South America for all four species; and geographical differentiation is lacking between stocks in the same species both for common as well as variant phenotypes despite the cosmopolitan distribution of these species. These results are not correlated with adaptations that favor inbreeding over outbreeding. nor is the possession of bacterial endosymbionts strongly correlated with enzyme variation. When the riequency of intraspecies variation was examined for the aurelia complex of species as a whole for 13 enzymes, mitochondrial DNA, and ribosomal DNA, differences between enzymes in frequency of variation could be seen, ranging from less than 2% for seven enzymes to 12.4% for glucosephosphate isomerase, a value similar to that observed for malic dehydrogenase, mitochondrial DNA, and ribosomal DNA in P. tetraurelia. The percentage of polymorphic enzyme loci in the complex as a whole was found to be much lower than that observed for other organisms. For the species more intensely studied in this paper the level of genetic polymorphism was also much lower, although P. biaurelia showed greater variability for two of the enzymes.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 29 (1982), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: One hundred eighty-eight stocks of Paramecium primaurelia, P. biaurelia, P. tetraurelia, and P. octaurelia were grown axenically and tested for five esterases, visualized by starch gel electrophoresis, in a search for variant stocks. The five esterases can be distinguished on the bases of their substrate specificity, sensitivity to an inhibitor, and response to different growth conditions. This paper addresses the nature of the electrophoretic change in mobility of the variant stocks in order that species relationships can be more accurately assessed. Crosses carried out in all four species show that single genes determine the differences in mobility between variant and common subtypes. Extracts of variant stocks that gave similar patterns were run against each other, tested for their sensitivity to the inhibitor, and the pattern was compared to that found in extracts of stocks with variant and common subtypes in other species. The majority of the variants in P. primaurelia, P. tetraurelia, and P. octaurelia show an electrophoretic mobility characteristic of a common subtype, or a variant, in another species. The same proportion of variant subtypes as common subtypes have mobilities similar to esterase subtypes found in other species. Of the four species examined in this paper, P. tetraurelia and P. octaurelia appear to be most closely related on the basis of shared esterase subtypes. In P. biaurelia the mobilities of most of the variants are unique, as are the common esterase subtypes in this species. P. biaurelia stands out as having the greatest number of esterase subtypes, with very few of them homologous to subtypes found in other species. This observation supports the idea of greater diversification of stocks within P. biaurelia than for the other three species.
    Type of Medium: Electronic Resource
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