Showing papers in "Archives of Microbiology in 1973"

Quantification of bacterial and fungal contributions to soil respiration

Abstract: 1. The theoretical principles and experimental procedures of a method for the direct measurement of the relative contributions of bacterial and fungal populations to soil respiration were described. 2. Differentiation was based on the selective inhibition of protein synthesis in procaryotic and eucaryotic cells by the antibiotics streptomycin and actidione. 3. Using an agricultural soil as an example, it was shown that the bacterial and fungal contributions were ca. 22% and 78%, respectively. 4. The possible advantages and limitations of the method for soil ecological studies are discussed.

Taxonomy of the marine, luminous bacteria

Abstract: One hundred and seventy-three strains of marine, luminous bacteria isolated from sea water, surfaces and intestines of fish, as well as from the luminous organs of fish and squid were submitted to an extensive phenotypic characterization A numerical analysis of the results grouped these strains into four clusters which were formed on the basis of overall phenotypic similarity One cluster, which was given the designationBeneckea harveyi, consisted of strains which had a moles% GC content in their DNAs of 465±13 and a single, sheathed, polar flagellum when grown in liquid medium Most of these strains had unsheathed, peritrichous flagella in addition to the sheathed, polar flagellum when grown on solid medium The two phenotypically similar clusters which were assigned the species designationsPhotobacterium phosphoreum andP mandapamensis consisted of strains which had 1–3 unsheathed, polar flagella and moles % GC contents in their DNAs of 415±07 and 429±05, respectively The cluster designatedP fischeri contained strains having 2–8 sheathed, polar flagella and a moles % GC content of 398±11 These four species could be further distinguished on the basis of a number of nutritional properties as well as other phenotypic traits The assignment of the luminous, marine bacteria to four species was supported by differences in the properties of the luminous system as well as differences in the pattern of regulation of spartokinase activity which are discussed The speciesB harveyi was found to be phenotypically similar to a number of previously characterized, non-luminous strains ofBeneckea which should probably be assigned to this species

Cell surface hydrophobicity and the orientation of certain bacteria at interfaces.

Abstract: Individual cells of Flexibacter aurantiacus CW7 and Hyphomicrobium vulgare ZV580 orientate themselves perpendicularly to the interface in air-water, oil-water and solid-water systems. Electrostatic phenomena probably are not involved in this orientation, since no evidence was found of any localized distribution of positively-charged ionogenic groups on the bacterial surface. It is suggested that the orientation results from a relatively hydrophobic portion of each cell being rejected from the aqueous phase of the system. This property also may be related to the formation of rosettes by these bacteria. Electron micrographs of thin sections of cells sorbed to araldite blocks show that the cell proper is not in contact with the solid surface, but is anchored to it by extracellular adhesive material. The extracellular materials may be of a polysaccharide nature.

Membrane leakage in Bacillus subtilis 168 induced by the hop constituents lupulone, humulone, isohumulone and humulinic acid

Abstract: The bactericidal activity of the hop constituents lupulone, humulone, isohumulone and humulinic acid against Bacillus subtilis 168 is shown to result from primary membrane leakage. This process leads to complete inhibition of active transport of α-methyl-d-glucopyranoside and several amino acids into whole bacteria and isolated membrane vesicles within 5 min at 37°C at the corresponding minimal inhibitory concentrations of 1, 2, 25 and 250 μg/ml, respectively. Inhibition of the respiratory chain, of protein, RNA and DNA synthesis seems to be a secondary event.

A new fla gene in Salmonella typhimurium--flaR--and its mutant phenotype-superhooks.

Abstract: An electron microscopic examination of eight non-flagellate strains of S. typhimurium revealed that an H1 (amber) mutant produced flagellar hooks and basal structures indistinguishable from those associated with the proximal end of normal flagella. No flagella-related structures were seen in strains with mutations in fla genes A, B, C, D, F, K or M. A mutant of a new fla complementation group, flaR, produced abnormal structures, termed “superhooks”, which resemble the hooks of normal flagella assembled end-to-end. The mutant locus, flaR, maps between flaM and flaAIII.

Pathways of glycollate metabolism in the blue-green alga Anabaena cylindrica.

Abstract: 1. Exogenous glycollate was assimilated by the blue-green alga Anabaena cylindrica. 2. About 50% of the C-1 carbon of 14C-1-glycollate (i.e.25% of the total carbon) was released as 14CO2 in the dark and also in the light in the presence of DCMU. Most of the 14CO2 released in the light in the absence of DCMU was refixed. 3. Assimilation was almost completely inhibited by α-hydroxy-2-pyridinemethane sulphonic acid, an inhibitor of enzymic glycollate oxidation. Cell extracts catalyzed the oxidation of glycollate to glyoxylate at rates sufficient to account for the in vivo assimilation. 4. Isonicotinylhydrazide, an inhibitor of the conversion of glycine to serine in higher plant/green algae glycollate metabolism, did not significantly affect glycollate metabolism in A. cylindrica. Short-term labelling experiments with 14C-1-glycollate in the light and dark did not show a significant metabolism of 14C via glycine and serine. However, the enzymes for the metabolism of glyoxylate via glycine, serine and hydroxypyruvate to glycerate were demonstrated in cell extracts, although the activity of the enzyme catalyzing the metabolism of serine to hydroxypyruvate was not sufficient to account for the in vivo rate of glycollate assimilation. 5. Cell extracts catalyzed the enzymic condensative decarboxylation of glyoxylate to tartronic semialdehyde and also the enzymic reduction of tartronic semialdehyde to glycerate. The activities in extracts were sufficient to account for the total in vivo photoassimilation of glycollate. The specific activity of malate synthase was insufficient to account for the total photometabolism of glycollate but exceeded the in vivo rate in the dark. 6. On the basis of the inhibitor and kinetic experiments and in terms of the enzymes detected, it appears that in the light glycollate is metabolized mainly via glyoxylate → tatronic semialdehyde → glycerate → 3-phosphoglycerate → (glycolytic pathway) → pyruvate → alanine plus tricarboxylic acid cycle and related compounds. The bulk of the CO2 released in the light is probably refixed via the Calvin cycle. In the dark, the glyoxylate, produced from exogenous glycollate, appears to be metabolized mainly by malate synthase directly to malate.

The growth unit of the mould Geotrichum candidum.

Abstract: Geotrichum candidum grew filamentously in batch culture. Hyphal fragmentation occurred during growth; mycelial fragments in the early part of the stationary phase had a mean length of 300 to 400 μm. The dry weight, total hyphal length, number of hyphal tips and turbidity of the culture all increased exponentially at about the same specific growth rate. The results suggested, the existence of a functional unit of growth consisting of a hyphal tip associated with a constant mean length of hypha. The hyphal growth unit was defined as the ratio between the total hyphal length and number of hyphal tips in the culture; for G. candidum this unit was about 100 μm long and its length remained constant when the organism's specific growth rate was varied by changes in temperature, carbon source or the incorporation of cycloheximide in the medium.

Glutamine synthetase of the nitrogen-fixing alga Anabaena cylindrica.

Abstract: High levels of glutamine synthetase, detected using both a biosynthetic assay (Pi release from ATP) and a γ-glutamyl transferase assay, are present in aerobically grown N2-fixing cultures of Anabaena cylindrica. The enzyme is soluble, has a pH optimum of 6.5–7.5, with a peak at 7.1–7.2 (biosynthetic activity) or 6.9 (transferase activity), and a temperature optimum at 30°C–40°C. Partially purified preparations are stable in air at 5°C for at least 3 days. Mg2+, Mn2+, Co2+ and Ca2+ support high rates of biosynthetic activity, Zn2+ is less effective and Cu2+ and Ba2+ are ineffective.

Ecological studies of Chloroflexis , a gliding photosynthetic bacterium

Abstract: Chloroflexis, a gliding, filamentous, photosynthetic bacterium, is present in the stratified algal-bacterial mats which occur in the 50°–70°C temperature range of alkaline hot spring effluents. The organism is in association with the alga in the upper, algal layer, and also forms thick, orange mats beneath the algal layer. Natural populations of Chloroflexis from these mats demonstrated light-stimulated uptake of some 14C-labelled organic compounds. Photosynthetic 14CO2 fixation by natural samples of Chloroflexis was investigated with respect to temperature, light intensity and mat depth. Bacterial photosynthesis was determined in samples in which algae were present by use of the inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU). Bacterial photosynthesis was maximal at depths down to about 3 mm and then decreased rapidly to very low levels at greater depths. The greatest amounts of bacteriochlorophyll pigments were also concentrated in the top 3–4 mm of the mat. The optimum light intensity for bacterial photosynthesis (about 400 ft-c) was considerably lower than the normal summer light intensity at the surface of the mat (5000-8000 ft-c). The temperature optima for photosynthesis by the bacterial component of natural mat samples from several sites of different temperatures in a hot spring thermal gradient were determined. Temperature optima approximated the environmental temperatures, indicative of the occurrence of strains of Chloroflexis adapted to different temperatures. Although bacterial standing crop was greatest in the temperature range 50°–55°C, maximum photosynthetic efficiency was observed at about 45°C. Sulfide was stimulatory to photosynthetic 14CO2 fixation by naturally occurring populations of Chloroflexis under field conditions. These data are consistent with the hypothesis that Chloroflexis may utilize sulfide as an electron donor for photosynthetic CO2 reduction. However, it is also likely that Chloroflexis grows photoheterotrophically in these mats, obtaining organic compounds from algal excretory products.

A study of copulation, sporulation and meiotic segregation in Candida lipolytica.

Abstract: We have attempted to optimize conjugation and sporulation in Candida lipolytica, by studying the conditions of culture and growth.

Rhodopseudomonas sulfidophila, nov. spec., a new species of the purple nonsulfur bacteria

Abstract: From marine mud flats a new type of photosynthetic purple bacterium was isolated. This type is described as a new species of the Rhodospirillaceae and is named Rhodopseudomonas sulfidophila. The cells are rod-shaped, 0.6 to 0.9 μ wide and 0.9 to 2.0 μ long, and motile by means of polar flagella. Cell division occurs by binary fission. The photosynthetic membrane system is of the vesicular type. The pigments consist of bacteriochlorophyll a and of carotenoids, most probably of the spheroidene group. A wide range of organic compounds can be utilized anaerobically in the light. Growth on organic compounds aerobically in the dark is also possible. Niacin, thiamin, biotin and p-aminobenzoic acid are required as growth factors. The new species needs 2.5% (w/v) sodium chloride for optimal growth. All strains show excellent photolithotrophic growth on hydrogen, hydrogen sulfide, and thiosulfate. They show a remarkably high sulfide tolerance. Sulfide and thiosulfate are oxidized to sulfate without an intermediate accumulation of elemental sulfur. The new species seems to be one of the most versatile types of photosynthetic bacteria isolated thus far.

Germanium incorporation into the silica of diatom cell walls

Abstract: 1. The diatoms, Nitzschia alba, Navicula pelliculosa, Cylindrotheca fusiformis, and Cyclotella nana, took up radioisotopically labelled germanic acid, 68Ge(OH)4, from their growth media and incorporated up to 80% of it into the silica of their cell walls. Silicification appeared to be required for germanium incorporation. 2. The uptake and incorporation of germanic acid was dependent upon the relative concentrations of Ge(OH)4 and Si(OH)4, i.e., the [Ge]/[Si]. 3. At [Ge]/[Si] of 0.01, no inhibition of growth or of silicic acid uptake by N. alba was observed. The cell morphology was also normal. 60 to 80% of the 68Ge(OH)4 taken up was incorporated. 4. At [Ge]/[Si] of 0.1, silicic acid uptake and growth of N. alba were inhibited by about 95%. Concomitantly, striking morphological aberrations occurred. 10 to 20% of the 68Ge(OH)4 taken up was incorporated. 5. The possible use of 68Ge(OH)4 for the study of silicon metabolism is discussed.

Cell wall composition and synthesis via Golgi-directed scale formation in the marine eucaryote, Schizochytrium aggregatum, with a note on Thraustochytrium sp.

Abstract: Cell walls of Schizochytrium aggregatum and Thraustochytrium sp. were mechanically isolated and subjected to chemical analysis. On a dry weight basis the cell walls contain 21–36% carbohydrate and 30–43% protein. The principal sugar (>95%) of the Schizochytrium wall is l-galactose, while the Thraustochytrium cell wall contains l-galactose, d-galactose and xylose with l-galactose predominating. Ultrastructurally the cell walls of both organisms consist of a laminated structure which yields thin, flexible, nearly circular scales (0.5–1.1 μ in diameter) upon sonic disintegration. Structures presumed to be developing wall scales are found within cisternae of the Golgi apparatus in both organisms. The chemical composition and method of formation of the cell wall in these two protists is distinctly different from that found in the Saprolegniales (Oomycetes), the group with which these organisms have hitherto been aligned.

The hyphal growth unit of wild type and spreading colonial mutants of Neurospora crassa.

Abstract: 1. The growth unit of a hypha is defined as the ratio between its total length and the number of tips which it possesses. The length of the growth units of two strains of Neurospora crassa remained approximately constant for hyphae which possessed up to 18 (spco 1) and 97 (spco 12) tips. 2. The length of the hyphal growth units of wild type and spreading colonial mutants of Neurospora crassa varied from 32 μm to 402 μm. 3. The length of the growth unit of spco 1 hyphae remained constant when the mould's specific growth rate was varied by temperature changes or by incorporating inhibitors in the medium. 4. There was a direct relationship between the radial growth rate of colonies of spco 1 and the strain's specific growth rate at different temperatures.

The effect of chloramphenicol on the production of cyanophycin granule polypeptide in the blue green alga Anabaena cylindrica.

Abstract: The cyanophycin or structured granule of the blue-green algae is composed of polypeptides which are copolymers of aspartic acid and arginine. The addition of chloramphenicol to an exponentially growing culture of the blue-green alga Anabaena cylindrica at concentrations which completely inhibit protein synthesis results both in the inhibition of growth and in the accumulation of the cyanophycin granule polypeptide (CGP). The chloramphenicol induced increase in CGP content is energy dependent. Removal of the chloramphenicol results in resumption of growth and the hydrolysis of the stored CGP. The data presented indicate that CGP is synthesized via a non-ribosomal system and are consistent with the idea that CGP serves as a cellular nitrogen reserve.

Nitrogen fixation by Anabaena cylindrica

Abstract: Blending Anabaena cylindrica cultures results in a loss of nitrogenase activity which is correlated with the breakage of the filaments at the junctions between heterocysts and vegetative cells. Oxygen inhibition of nitrogen fixation was significant only above atmospheric concentrations. Nitrogen-fixation activities in the dark were up to 50% of those observed in the light and were dependent on oxygen (10 to 20% was optimal). Nitrogenase activity was lost in about 3 h when cells were incubated aerobically in the dark. Re-exposure to light resulted in recovery of nitrogenase activity within 2 h. Blending, oxygen, or dark pre-incubation had similar effects upon cultures grown under air or nitrogen and did not inhibit light-dependent CO2 fixation. We conclude that heterocysts are the sites of nitrogenase activity and propose a model for nitrogen fixation by Anabaena cylindrica.

Classification of staphylococci based on chemical and biochemical properties

Abstract: In the present work the chemical cell wall composition and some other biochemical characteristics were studied in staphylococci with the intention of utilizing the data obtained in their classification.

Preparation and characterization of a soluble nitrate reductase from Azotobacter chroococcum.

Abstract: The assimilatory nitrate reductase of the N2-fixing bacterium Azotobacter chroococcum has been prepared in a soluble form from cells grown with nitrate as the nitrogen source, and some of its properties (electron donors and cofactors, Kmvalues for substrates, molecular weight, inhibitors, activators, etc.) have been studied. The enzyme is of an inducible nature and can exist in two interconvertible forms, either active or inactive.

Effects of organic compounds on growth of chemostat cultures of Thiomicrospira pelophila, Thiobacillus thioparus and Thiobacillus neapolitanus.

Abstract: Cultures of Thiomicrospira pelophila, Thiobacillus thioparus and Thiobacillus neapolitanus were grown in thiosulfate-limited chemostats in a mineralsthiosulfate medium with and without organic supplements. Acetate, succinate and mixtures of amino acids increased the dry weight by 12–24% and the protein by 11–38%. Addition of both acetate and succinate had a cumulative effect. Saccharose, glucose, fructose, ribose, glycerol, glycerate, pyruvate, lactate or malate were without effect. The increase in dry weight of T. neapolitanus by 14C-acetate was directly related to the relative contribution of this compound to the total cell carbon.

Effect of pesticides on blue-green algae.

Abstract: Effect of pesticides, i.e., Benzene Hexachloride, Lindane, Diazinon and Endrin that are often used in India was observed on nitrogen-fixing blue-green algae Cylindrospermum sp., Aulosira fertilissima Ghose and aerobically non-nitrogen-fixing blue-green alga Plectonema boryanum strain 594. These algae were sensitive for BHC in comparison to other pesticides. A. fertilissima and P. boryanum were more resistant than Cylindrospermum sp.

Ultrastructural changes of the fission yeast (Schizosaccharomyces pombe) during ascospore formation.

Abstract: The fission yeast, Schizosaccharomyces pombe, a homothallic haploid strain NCYC 132, was induced to flocculate and conjugate to facilitate the study of the ascosporogenesis. It is found that two nuclei are formed during meiosis I and these nuclei divide again during meiosis II. The forespore membrane emerges at the beginning of meiosis II, elongates without fragmentation to enclose the nucleus and other cytoplasmic organelles, including mitochondria and ER. Meiosis occurs without fragmentation of the nuclear membrane. Immediately after the enclosure of the nucleus, the forespore membrane is resolved into two separate membranes. The inner one appears to become the spore plasmalemma and the outer one, if it persists, becomes a limiting membrane of the spore wall. In some cases, the outer membrane is seen to be ruptured. Spore wall materials deposite in the space between the inner and outer membranes.

Sulfate reduction in a cell-free system of Chlorella. The ferredoxin dependent reduction of a protein-bound intermediate by a thiosulfonate reductase.

Abstract: During sulfate reduction in a cell-free system ofChlorella activated sulfate of APS is transferred to a thiosulfonate reductase. The sulfate thus bound to the thiosulfonate reductase (i.e. bound sulfite) is reduced to bound sulfide in a ferredoxin dependent reaction. This bound sulfide can be used with O-acetylserine as acceptor for cysteine biosynthesis; serine and O-phosphoserine are not used. An assaysystem for thiosulfonate reductase activity using methylviologen dependent reduction of S2O4 2− to S2− is developed and a procedure for isolating thiosulfonate reductase fromChlorella cells is presented. During isolation of thiosulfonate reductase a low weight molecular factor, needed for optimal enzyme activity was lost. The bound sulfite seems to be attached to this factor. Reduction of APS or GS-SO3H to the level of S2− is inhibited by cysteine. 50% inhibition of GS-SO3H reduction was found at a molar cysteine concentration of 6.8×10−5.

Untersuchungen zur Entstehung von Dl-Milchsäure bei Lactobacillen und Charakterisierung einer Milchsäureracemase bei einigen Arten der Untergattung Streptobacterium

Abstract: Eine kritische Uberprufung der von den verschiedenen Arten der Gattung Lactobacillus gebildeten Milchsaure ergab, das zwar die D(-)-Laktatbildner reines D(-)-Isomer, die L(+)-Laktatbildner aber immer auch einige wenige Prozente des anderen Isomers bilden. Letzteres beruht auf der Anwesenheit einer sehr schwach aktiven NAD-abhangigen D-Laktatdehydrogenase neben der hochaktiven NAD-abhangigen L-Laktatdehydrogenase.

Studies of Sulfate Utilization by Algae

Abstract: 1. Incubation of high specific activity adenosine-5′-phosphosulfate (AP35S) with crude enzyme fractions or purified APS-sulfotransferase from wildtype and from a mutant which does not grow on sulfate (Sat2-) leads to binding of label to protein as judged by separation on Sephadex G-25. Crude extracts of mutants Sat1-, Sat6-, and Sat7-R1 lacking APS-sulfotransferase show 10 fold lower binding, indicating that APS-sulfotransferase activity is required. 2. Protein-bound radioactivity is not released by mild acid and exchanges with sulfite excluding bound APS; this suggests a linkage of the organic thiosulfate type (R-S-SO3-). Labeled protein releases radioactive SO32- and GSSO3- with gluthathione (GS-); with BAL or S2-, SSO32- is released. 3. The reaction of APS with APS-sulfotransferase is heat labile, but once bound, the radioactivity is still released by thiols from the heated protein. 4. Aged purified APS-sulfotransferase loses binding activity which is restored by adding the supernatant from heated fresh extract, indicating the participation of a cofactor, consistent with the view that a low molecular weight carrier participates in the main pathway of reduction.

Ammonia assimilation in blue-green algae.

Abstract: The occurrence of alanine dehydrogenase (AlaDH), glutamate dehydrogenase (GDH), and 2-ketoglutarate: glutamine amidotransferase (GGAT), has been surveyed in a number of blue-green algae. Among nine unicellular strains grown with nitrate, and belonging to five of the major typological groups, AlaDH was present in seven, and GDH in all eight that were assayed. In ten filamentous strains grown with nitrate, and belonging to the three nonheterocyst-forming and four heterocyst-forming groups, AlaDH was present in six, but both AlaDH and GDH were present in only one strain. In those strains which could be grown with N2 as sole nitrogen source, levels of GDH were generally lower, and AlaDH higher in cells fixing N2 than in those growing with nitrate. GGAT was undetectable in N2-grown cells. Two unicellular and three filamentous strains were tested for their ability to use L-alanine, L-glutamate, L-glutamine, and L-asparagine as sole sources of nitrogen. Of these, L-asparagine was utilized most effectively. There was little difference in levels of GDH in cells grown with nitrate or with L-asparagine, while the levels of AlaDH were slightly lower in cells grown with L-asparagine.

Structure and plugging of septa of wild type and spreading colonial mutants of Neurospora crassa.

Abstract: 1. The structure and plugging of septa of several Neurospora crassa strains were studied. 2. Septa were occluded by an electron dense plug. Woronin bodies were never observed. 3. Nearly all the septa found within the peripheral 0.5 to 1.0 mm of colonies of spco 12 were plugged but plugged septa were never observed in cot 3 and only rarely in spco 4, even 11 mm from the colony's circumference. 4. Lines of vesicles were observed in the cytoplasm and traversing the septal pores of spco 1 hyphae. The mean diameter of these vesicles and the vesicles found at the hyphal tip were identical.

Effect of anaerobiosis on photosynthetic reactions and nitrogen metabolism of algae with and without hydrogenase

Abstract: The effect of anaerobic (N2+CO2) pre-incubation in the dark on photosynthetic reactions (O2 evolution, measured manometrically and with the oxygraph; fluorescence; and photoproduction of H2, measured with the mass spectrometer) was studied in algae with hydrogenase (strains of Chlorella fusca, C. kessleri, C. vulgaris f. tertia, and Ankistrodesmus braunii) and in algae without hydrogenase (strains of Chlorella vulgaris, C. saccharophila, and C. minutissima).

A new species of marine labyrinthulid Labyrinthuloides yorkensis gen. nov. spec. nov. —Cytology and fine structure

Abstract: The structure and life cycle of a new genus and species of labyrinthulid, Labyrinthuloides yorkensis, is described from observations of pure cultures. Uninucleate cells are capable of gliding by means of ectoplasmic nets which push or pull the cells across the substrate. The net elements do not enrobe the cells and motility is reversible. Sporulation occurs by successive bipartition or progressive cleavage of the protoplast. Biflagellated zoospores with an anterior tinseled flagellum and posterior whiplash flagellum are formed as are non-replicating amoebae and plasmodia. The fine structure includes centrioles with a single large granule in the lumen and numerous cytoplasmic inclusion bodies with associated membrane complexes. The membrane-inclusion arrays are each found within a delimiting vesicle membrane.