bluuebunny/crossref_metadata_2025 huggingface dataset:
Environmental effects on lipids of Mycobacterium phlei ATCC 354
Authors: Dhariwal K. R. , Chander A. , Venkitasubramanian T. A.
Published: April 2010

Phospholipids of Mycobacterium phlei ATCC 354 are cardiolipin, phosphatidyl ethanolamine, tri- and tetra-acylated dimannophosphoinositide and tetraacylated pentamannophosphoinositide. Contrary to a previous report (Dhariwal et al. 1975, Experientia, 31: 776–778), monomannophosphoinositide was not evident. A linear decrease in total lipid was observed with an increase in the nitrogen content of the medium. An inverse relationship was observed with the carbon supply in the medium. Cells grown on a medium with limited nitrogen contained more saturated fatty acids, whereas cells grown on a medium with limited carbon contained more unsaturated fatty acids. No significant change in phosphatidyl ethanolamine resulted from changing the carbon and nitrogen supply in the medium. Phosphatidylinositol mannosides were the major phospholipids in glycerol-grown cells, but in glucose-grown cells concentrations of phosphatidylinositol mannosides and cardiolipin were the same. Glyceride content of cells increased with an increase in carbon supply and decreased with an increase in nitrogen supply in the medium. Phosphatidylinositol mannosides were the major phospholipid component at 37 °C, whereas cardiolipin was the major phospholipid in cells grown at 27 °C. Among fatty acids, a considerable decrease in palmitic acid with a concomitant increase in palmitoleic and oleic acid was observed with a decrease in growth temperature from 37 to 27 °C. The results show that there is a preferential production of certain lipid constituents under various cultural conditions.
Regulation of catalase level in Escherichia coli K12
Authors: Yoshpe-Purer Yona , Henis Yigal , Yashphe Jacob
Published: April 2010

The synthesis of catalase (H2O2:H2O2 oxidoreductase, EC 1.11.1.6) in Escherichia coli K12 was regulated by repression–induction and catabolite repression. Transient repression by glucose was also demonstrated. Under certain conditions, preferential synthesis was observed. Enzyme synthesis was induced in glycerol-grown cells by 0.15 to 0.2 μmol H2O2 (5–6 μg) per millilitre of culture, added at 10 to 15-min intervals, which were shortened progressively as the level of catalase in the cells rose. Catabolite repression of catalase synthesis was demonstrated with glucose, glycerol, maltose, lactose, xylose, mannitol, sorbitol, and trehalose, and to a lesser extent with arabinose, galactose, sucrose, rhamnose, and dulcitol as sole carbon sources in mineral medium. Catabolite repression was prevented by anaerobic growth and nitrogen starvation. All TCA-cycle intermediates examined afforded high catalase levels when serving as sole carbon sources. High catalase levels were also obtained when cells were grown on nutrient broth, nutrient agar, casitone, and peptone.
Small cells in pure cultures of Agromyces ramosus and in natural soil
Authors: Casida Jr. L. E.
Published: April 2010

Previously, transmission electron-microscopic observations of thin-sectioned and frozen-etched preparations of microorganisms concentrated directly from soil showed many cells that were considerably smaller than the cells found in pure cultures isolated from soil. The present study shows that pure cultures of the soil bacterium Agromyces ramosus can produce cells as small as those observed in natural soil. Growth on a nutritionally limiting medium and the presence of an agar surface contributed to the occurrence of these small cells.
Tree host range and world distribution of the ectomycorrhizal fungus Pisolithus tinctoriu
Authors: Marx Donald H.
Published: April 2010

The natural occurrence of Pisolithus tinctorius has been confirmed in 33 countries of the world and in 38 states in the United States. This ectomycorrhizal fungus is found associated with various tree species in nurseries, urban areas, orchards, forests, and strip-mined spoils. Experiments have proved that this fungal symbiont forms ectomycorrhizae with Abies procera, Betula pendula, Carya illinoensis, 11 species of Eucalyptus, 30 species of Pinus, Pseudotsuga menziesii var. menziesii, 2 species of Quercus, and Tsuga heterophylla. Pisolithus has also been reported growing under natural conditions in association with three additional species of Betula, two species of Eucalyptus, nine species of Pinus, and eight species of Quercus, Populus tremuloides, Pseudotsuga grandidenta, and Salix humilis.This fungal symbiont has great potential in forestation efforts because of (1) the availability of practical techniques for artificially introducing it into nursery soils; (2) its ability to improve tree survival and growth in the nursery and the field; (3) its near worldwide distribution on a variety of sites; and (4) its broad host range encompassing many of the world's most important tree species.
Metabolism of a monoterpene alcohol, linalool, by a soil pseudomonad
Authors: Madyastha K. M. , Bhattacharyya P. K. , Vaidyanathan C. S.
Published: April 2010

A microorganism of the genus Pseudomonas has been isolated from the soil by enrichment culture techniques with linalool(I) as the sole source of carbon and energy. The organism is also capable of utilizing limonene, citronellol, and geraniol as substrates but fails to grow on citral, citranellal, and 1,8-cineole. Fermentation of linalool by this bacterium in a mineral salt medium results in the formation of 10-hydroxylinalool(II), 10-carboxylinalool(III), oleuropeic acid(IX), 2-vinyl-2-methyl-5-hydroxyisopropyl-tetrahydrofuran(linalool oxide, V), 2-vinyl-2-methyl-tetrahydrofuran-5-one(unsaturated lactone, VI), and few unidentified minor metabolites. Probable pathways for the biodegradation of linalool are presented.
Outer-membrane damage in sublethally heated Escherichia coli K-12
Authors: Hitchener Beverley J. , Egan Aubrey F.
Published: April 2010

Exponentially grown cells of Escherichia coli K-12 heated at 48 °C in potassium phosphate buffer at pH 7.0 were structurally injured before death. During heating for 60 min about 20% of the cellular lipopolysaccharide (LPS) was released from the outer membrane into the heating medium. Removal of 30% of the cellular LPS, by washing the cells in buffer containing ethylenediaminetetraacetic acid (EDTA), caused no significant increase in the rate of death and structural injury produced by heating. The addition of EDTA to the heating medium produced only a slight increase in the rate of thermal death but a large increase in the rate of structural injury. By a combination of heating at 48 °C and washing with EDTA, a maximum of 50% of the LPS was released from cells. These results taken together suggest that structural injury and loss of LPS are not the direct causes of death. The addition of 5 mM Mg2+ to the heating medium protected the cells from death and structural injury caused by heating at 48 °C.
Pollution indicator bacteria associated with municipal raw and drinking water supplies
Authors: Clark James A. , Pagel Jane E.
Published: April 2010

A total of 3819 bacterial cultures isolated from municipal water samples were identified using a combination of Enterotubes and confirmatory media. Frequency distributions for the different genera or groups of bacteria were similar for raw water and drinking water isolations, except for Escherichia organisms which doubled their frequency in raw water. Differences between the membrane filter (MF) and presence–absence (P–A) test with regard to types of organisms isolated were limited to Klebsiella organisms which were preferentially cultured from MF plates. Members of the genus Enterobacter were isolated more than twice as frequently as any of the other coliform genera dealt with in this study. Aeromonas organisms were detected almost as often as such individual genera as Escherichia, Citrobacter, or Klebsiella.Although non-lactose fermenting colonies (false-negatives) of the coliform genera would not be detected by the MF technique, their lack of detection would likely be offset by the Aeromonas colonies (false-positives). At least 25% of the coliform isolates were either anaerogenic or non-lactose fermenters and would therefore go undetected by the most probable number (MPN) technique.
Polymorphism of Malassezia furfur
Authors: Salkin Ira F. , Gordon Morris A.
Published: April 2010

Alterations in the morphologic and physiologic characters of 11 isolates of Pityrosporum orbiculare were noted upon prolonged maintenance in pure culture. Successive subculturing of each isolate resulted in its progressive conversion from globose (P. orbiculare) through ovoid to cylindrical (P. ovale) form. Globose forms utilized neither olive oil nor Tween 20 as a sole carbon source, nor KNO3 as a sole source of nitrogen, while ovoid and cylindrical forms utilized both of these carbon sources, and one of four strains of the cylindrical form assimilated KNO3. These results suggest that P. orbiculare and P. ovale are stages in the complex developmental cycle of a single species (Malassezia furfur), but the three names should be preserved until the life cycle is more fully understood.
Further studies on the formation of choline sulfate by bacteria
Authors: Fitzgerald J. W. , Luschinski P. C.
Published: April 2010

Cell extracts of Pseudomonas C12B synthesized choline sulfate (COS) from SO42−, choline chloride, and ATP. However, most of the COS-forming activity was found in culture medium supernatants of this bacterium, and that which remained with the cells was cell wall-associated. Enzyme release was independent of the carbon and (or) sulfur source used for growth and was not suppressed by increasing the divalent cation concentration of the medium. The COS-synthesizing system was inhibited in vitro by L-cysteine [Formula: see text], SO42− (> 0.1 mM), and choline chloride (> 0.1 M). L-Cysteine (0.1–5.0 mM) did not repress the synthesis of enzymes present in the system. COS formation from SO42− in vitro was increased 2.8-fold by 10 mM adenosine 5′-phosphosulfate (APS) and 5-fold by 1 mM 3′-phosphoadenosine-5′-phosphosulfate (PAPS) during a 4-h incubation period. APS (10 mM) also inhibited the incorporation of 35SO42− into COS. Culture supernatants incubated with Na235SO4 produced two 35S-labelled metabolites having electrophoretic mobilities similar to those exhibited by authentic APS and PAPS. The synthesis of these metabolites was also inhibited in vitro by unlabelled APS and by L-cysteine.
Electron-microscopic study of the development of an equine adenovirus in cultured fetal equine kidney cells
Authors: Shahrabadi M. S. , Marusyk R. G. , Crawford T. B.
Published: April 2010

Sequential changes induced by an equine adenovirus in cultured fetal equine kidney cells were studied by electron microscopy. The first morphological change was the appearance of type I inclusions. These inclusions developed to type II inclusions which appeared as ring forms. Type III inclusions were formed within the central part of type II inclusions and finally filled up most of the nuclear space. As the infection proceeded, type IV inclusions which appeared as dense dark-staining spheres were formed at the center of the type III inclusions and also inside the cytoplasm. These dark-staining spheres developed and their center was filled with light-staining material and virus particles which eventually resulted in the formation of type V inclusions. Autoradiography study showed that types I, II, and III were composed of nucleoprotein and type IV was composed of protein.
Preenrichment procedure for detection of Salmonella in gelatin
Authors: Park C. E. , Rayman M. K. , Stankiewicz Z. K. , Hauschild A. H. W.
Published: April 2010

Trypticase soy broth was superior to nutrient and lactose broths as a preenrichment medium for the detection of Salmonella in artificially and naturally contaminated gelatin. The detection rates for Salmonella were further enhanced when homogenization of the gelatine–broth mixture was accomplished by the use of gelatinase rather than by heating to 45 °C. Detection rates were also increased by adjusting the pH of the gelatine–broth mixture to 7.0, the optimum pH for gelatinase (EC 3.4.23.2) activity.
ATP and acetylene-reducing activity of a sulfate-reducing bacterium
Authors: Sekiguchi T. , Noguchi A. , Nosoh Y.
Published: April 2010

A sulfate-reducing bacterium, a strain of Desulfovibrio vulgaris, when lactate or pyruvate was supplied as an electron and energy source, reduced acetylene only in the presence of sulfate. Acetylene reduction started after a lag of 1 h. H2 which acts as an electron and energy source for sulfate reduction was unable to reduce acetylene even in the presence of sulfate. It was suggested, from the measurements of the amounts of adenine nucleotides of the bacterium incubated under various conditions, that the bacterium is able to reduce acetylene at a high ATP level or a high ATP/ADP ratio.
Effets de concentrations élevées de sels sur la croissance, la sporulation et la pigmentation de Trichoderma spp.
Authors: Gindrat D.
Published: April 2010

On agar media supplemented with NaCl (5% = 856 mM), seven Trichoderma species aggregates and an isolate intermediate between T. harzianum and T. viride (T. 410) grew more slowly, sporulated poorly, and there was no characteristic pigmentation of the colonies. NaCl or KCl concentrations inducing 'albinization' differed with different isolates. CaCl2 (90–270 mM) reversed the anti-sporulating effect of NaCl (856 mM) on T. 410, and stimulated conidiation in media with no NaCl added. Gliocladium virens, but not G. roseum, reacted like Trichoderma to NaCl. Fourteen other fungal genera offered various reactions. Since 856 mM NaCl decreases osmotic potential (π) of the media used from −1.2 to −41 bars, the influence of π on T. 410 was examined. After 3 to 4 days, maximal growth was observed between −1.2 and −10 bars. Growth was reduced to 50% at about −30 bars. No growth occurred at about −90 bars. No pigmentation was observed at −32 bars (NaCl) and −41 bars (KCl). Abundant sporulation and pigmentation occurred at −31 bars with CaCl2 as sole electrolyte added. Na+ was toxic at high concentration. Results are discussed in view of possible use of Trichoderma in biological control.
Effects of the herbicides fluometuron and prometryn on Rhizoctonia solani in soil cultures
Authors: Beam H. Wayne , Curl E. A. , Rodriguez-Kabana R.
Published: April 2010

Responses of Rhizoctonia solani to herbicides in soil cultures were assessed by measuring soil enzyme activity and other growth-related factors. Both β-galactosidase (EC 3.2.1.23) and phosphatase (EC 3.1.3.1, 3.1.3.2) activities were highly correlated with amounts of mycelium in soil. Both enzyme activities were reduced significantly by either fluometuron or prometryn at 40 μg/g of soil; the pathogen was more distinctly suppressed by fluometuron and showed a stronger tendency to overcome the effects of prometryn with time. Inhibition was also reflected in reduced utilization of glucose and less CO2-C evolved. Except for an increase in β-galactosidase activity in the presence of 1 μg fluometuron, low levels of either herbicide had little effect on the pathogen.
Suitability of some enrichment broths and diluents for enumerating cold- and heat-stressed Vibrio parahaemolyticus
Authors: Beuchat L. R.
Published: April 2010

Vibrio parahaemolyticus cells were injured by chilling and heating, and their recovery was tested in glucose–salt–Teepol broth (GSTB), tryptic soy broth containing 7% NaCl (TSBS), Horie – arabinose – ethyl violet broth (HAEB), and water blue – alizarin yellow broth (WBAY). Exponential phase cells were more sensitive to cold shock than were stationary phase cells. Exposure of chill-injured V. parahaemolyticus to GSTB and TSBS resulted in 70 to 80% death; about 70% lethality was noted for heat-injured cells inoculated into TSBS. Neither HAEB nor WBAY enrichment media were lethal to stressed cells, although rates of growth were retarded. The 3% NaCl in 0.1 M potassium phosphate (pH 7.0) diluent proved to be most suitable for protecting against inactivation of cold- and heat-injured cells.
Antagonistic interactions of phylloplane bacteria with Drechslera dictyoides (Drechsler) Shoemaker
Authors: Austin Brian , Dickinson Colin H. , Goodfellow Michael
Published: April 2010

Strains of Listeria denitrificans (E2), Psendomonas fluorescens (C37 and C92), and Xanthomonas campestris (D119), isolated from the phylloplane of Lolium perenne (S24), were antagonistic to Drechslera dictyoides (Drechsler) Shoemaker. From in vitro and in vivo experiments it was deduced that their mode of activity included an initial inhibition of spore germination, a retardation in the rate of germ-tube elongation, and ultimately lysis of the hyphae. The effects were expressed on the plant in terms of reduced levels of disease symptoms and sporulation.
Eburicol, lichesterol, ergosterol, and obtusifoliol from polyene antibiotic - resistant mutants of Candida albicans
Authors: Subden R. E. , Safe L. , Morris D. C. , Brown R. G. , Safe S.
Published: April 2010

Two classes of polyene-resistant mutants were isolated from survivors of N-methyl-N′- nitro-N-nitrosoguanidine treatment of a wild-type Candida albicans. An analysis of the major sterols of one class revealed an accumulation of lichesterol and fecosterol while the other class accumulated eburicol, obtusifoliol, and lanosterol with minor quantities of C28 sterols.
Destruction de Microbacterium lacticum, Escherichia coli et Staphylococcus aureus au cours du séchage du lait par atomisation. II. Influence des conditions de séchage
Authors: Chopin A. , Mocquot G. , Graet Y. Le
Published: April 2010

Bacterial death during spray drying of skim milk is essentially related to the outlet temperature of the spray drier and the type of bacteria. Under industrial spray drying conditions, survival rates of Microbacterium lacticum, Staphylococcus aureus and Escherichia coli were 50, 2, and 0.002%, respectively. These rates may vary by a 104 factor for outlet temperatures between 65 and 105 °C. No simple mathematical equation could be derived to describe the relation between bacterial death rates and outlet temperature. Our results suggest that bacterial death is due in most cases to a heating effect during the last stages of drying when the temperature of the powder particle approaches that of the air at the outlet. [Traduit par le journal]
Radioimmunodiffusion technique for determining diphtheria antitoxin
Authors: Maniar A. C. , Howland B. E.
Published: April 2010

A radioimmunodiffusion technique for detecting low levels of diphtheria antitoxin was developed. Diphtheria toxoid was labelled with 125I to facilitate detection of lines of precipitation by the use of X-ray film, the lower limit of detection being 0.001 unit per millilitre of diphtheria antitoxin.
Metabolic development and mitochondrial changes during cyclopiazonic acid production in Penicillium cyclopium
Authors: Neethling Dianne C. , McGrath Robert M.
Published: April 2010

During a study of cyclopiazonic acid (total α- and β-cyclopiazonic acids, CA) production by Penicillium cyclopium Westling, it was found that nitrogen depletion controlled the advent of secondary metabolism and that nitrate reduction was not rate-limiting. In concert with N depletion both tryptophan (Trp) biosynthesis and glucose catabolism fell. The rate of Trp production dropped to match the rate of CA biosynthesis. Glucose utilization varied between an early and late preference for the pentose cycle, with a mixture of pentose and Emden–Meyerhof pathways at an intermediate time. This pattern may well reflect the need for erythrose-4-phosphate in Trp biosynthesis. Additions of Trp caused a drop in CA production possibly because of repression of Trp synthetase. Exogeneous dimethylallylpyrophosphate (DMAPP) increased CA biosynthesis, while mevalonic acid had no effect which suggested a rate-limiting step between these two metabolites. These changes probably best fit Bu'Lock's hypothesis that secondary metabolism links fermentative and aerobic metabolism (ATP generation). In this case protein and polyisoprenoid biosynthesis, sugar utilization, and energy requirements would all be interlocked with the advent of secondary metabolism. The possible relationship between the observed metabolic changes and energy control were supported by electron-microscopic examination of the mitochondria in situ, when these ATP-generating organelles underwent major changes. Addition of ATP to the culture depressed CA production, as did excessive aeration. The metabolic regulator cAMP had no effect other than to increase autocatalysis.
ICMSF methods studies. VIII. Comparative study for the enumeration of Clostridium perfringens in foods
Authors: Hauschild A. H. W. , Gilbert R. J. , Harmon S. M. , O'Keeffe M. F. , Vahlefeld R.
Published: April 2010

Four methods were compared in an international comparative study for the enumeration of Clostridium perfringens: the SFP (Shahidi-Ferguson perfringens) agar (A), TSC (tryptose–sulfite–cycloserine) agar (B), SC (sulfite–cycloserine) agar (C), and neomycin blood agar (D) methods. The confirmed C. perfringens counts were slightly lower for D than for A–C. The percentages of presumptive colonies confirmed as C. perfringens were essentially the same in each method. The relative numbers of nonspecific colonies were the lowest in C, followed by B, D, and A. The methods were also compared for simplicity and for aspects associated with the recognition and selection of presumptive colonies.
Nitrous oxide as end product of denitrification by strains of fluorescent pseudomonads
Authors: Greenberg E. P. , Becker G. E.
Published: April 2010

Growing cultures of several strains of Pseudomonas fluorescens and Pseudomonas chlororaphis produced N2O as the only detectable gaseous product of denitrification, and other strains produced N2 as the gaseous end product of denitrification. All of the nitrogen in NO3− or NO2− added to cell suspensions of the N2O-producing strains P. fluorescens PJ 185 and P. chlororaphis B-560 was recovered as N2O. All of the nitrogen in NO3− or NO2− added to cell suspensions of the N2-producing strain P. fluorescen PJ 70 was converted to N2. Cell extracts of P. fluorescens PJ 70, PJ 185, and P. chlororaphis B-560 exhibited NO3− reductase activity when sodium succinate was the electron donor. Reduced nicotinamide adenine dinucleotide and flavine adenine dinucleotide were required to demonstrate NO2− reductase activity in cell extracts.
The intracellular reserve polysaccharide of Clostridium pasteurianum
Authors: Darvill A. G. , Hall M. A. , Fish J. P. , Morris J. G.
Published: April 2010

An amylopectinlike polysaccharide (granulose) was the only glucan produced in significant quantities by six wild-type strains of Clostridium pasteurianum grown in glucose minimal medium. The intracellular polysaccharide granules laid down before sporulation contained only this amylopectin. No intracellular dextran was discovered in these wild-type strains, nor in a granulose-negative mutant strain of C. pasteurianum possessing an ADP glucose pyrophosphorylase (EC 2.7.7.27) but lacking a granulose synthase (i.e. ADPglucose-α-1,4-glucan glucosyl transferase, EC 2.4.1.21). Furthermore, methylation analysis demonstrated that (1 → 6) linked α-D-glucose units accounted for less than 2% of the entire glucose content of these organisms.
Deoxyribonucleic acid relationships among marine vibrios pathogenic to fish
Authors: Schiewe Michael H. , Crosa Jorge H. , Ordal Erling J.
Published: April 2010

Polynucleotide sequence relationships among 19 strains of marine vibrios, 15 of which were pathogenic to fish, were assessed by analysis of DNA–DNA homo- and hetero-duplexes with the endonuclease S1. DNA base compositions (mole% guanine–cytosine (GC) of selected vibrio strains were determined by thermal denaturation. Pathogenic strains from the Pacific Northwest had identical mole % GC but could be divided into two discrete, yet related, DNA-homology groups. One highly related group was typical of Vibrio anguillarum and showed greater than 70% within-group polynucleotide sequence homology. Second group (designated V1669) showed greater than 83% within-group homology but only about 60% relatedness to V. anguillarum. Neither group showed a significant degree of relatedness to V. parahaemolyticus (biotypes parahaemolyticus or alginolyticus) or to representative strains of any of the other previously described homology groups which we tested.
Effects of certain cations on the formation and infectivity of Phytophthora zoospores. 2. Effects of copper, boron, cobalt, manganese, molybdenum, and zinc ions
Authors: Halsall D. M.
Published: April 2010

The effects of copper, boron, cobalt, manganese, molybdenum, and zinc on the production of zoosporangia by P. cinnamomi and P. drechsleri in the presence of favourable concentrations of calcium, magnesium, potassium, and iron were investigated. Copper ions were the most effective in reducing the numbers of zoosporangia formed by both fungal species. Molybdenum was also slightly inhibitory.Total inhibition of mycelial growth occurred between 1 and 5 × 10−5 M Cu2+ whereas total inhibition of sporangial formation occurred between 1 and5 × 10−7 M Cu2+. At copper concentrations between 10−5 M and 5 × 10−7 M, many P. drechsleri zoosporangia were abnormal in appearance and nonviable.Infection of eucalypt cotyledons by P. drechsleri zoospores was inhibited by 10−6 M Cu2+ but this inhibition was reversed by EDTA (10−4 M). There was no evidence for interaction between Cu2+ and Ca2+, Mg2+, K+, or Fe2+ present in the solutions used in the axenic production of zoospores. Preliminary pot trials indicated that CuSO4 had a protective action for safflower seedlings to infection by P. drechsleri when CuSO4 was applied as a dilute solution over the infection period.
Symbiotic effectiveness of antibiotic-resistant mutants of fast- and slow-growing strains of Rhizobium nodulating Lotus species
Authors: Pankhurst Clive E.
Published: April 2010

Mutants resistant to 16 individual antibiotics were isolated from two fast-growing and two slow-growing strains of Lotus rhizobia and their symbiotic effectiveness on Lotus pedunculatus evaluated. Resistance to streptomycin, spectinomycin, chloramphenicol, and tetracycline (inhibitors of protein synthesis) was associated with little or no loss of effectiveness with all four strains but resistance to nalidixic acid and rifampicin (inhibitors of nucleic acid synthesis), and to D-cycloserine, novobiocin, and penicillin (inhibitors of cell wall–cell membrane synthesis) was associated with significant loss of effectiveness in 20–100% of the mutants. Resistance to viomycin, neomycin, kanamycin, and vibramycin was associated with loss of effectiveness with mutants of the two fast-growing strains but not with mutants of the two slow-growing strains. When tested on four alternate host legumes individual mutants of a slow-growing strain showed significantly different levels of effectiveness. The results suggest that both the inherent characteristics of the bacterium and of the host plant will influence the symbiotic effectiveness of antibiotic-resistant mutants of Rhizobium.
Propriétés immunologiques de diverses fractions de la paroi d'une souche sauvage et d'une souche mutante de Saccharomyces cerevisiae Hansen
Authors: Kolodynski J. , Bizeau C. , Galzy P.
Published: April 2010

Some fractions of the Saccharomyces cerevisiae cell wall have been prepared by the action of Helix pomatia juice on intact cells. Immunosera were obtained by injecting rabbits with these fractions. Immunofluorescence reactions, obtained with these sera, show that some fractions of mannopeptides when extracted from a "smooth-colony" mutant strain, have lost antigenic determinants.
Isolation of sporopollenin from four myxobacteria
Authors: Strohl William R. , Larkin John M. , Good Barry H. , Chapman Russell L.
Published: April 2010

Sporopollenin, a resistance material previously found only in algae, fungi, pollen grains, and in some plant spores, has been found in four species of Myxococcus. Sporopollenin was isolated from vegetative cells and myxospores of the myxobacteria tested but it was not detected in any of the other bacteria tested.
The catabolism of L-tyrosine by an Arthrobacter sp.
Authors: Blakley E. R.
Published: April 2010

An Arthrobacter sp. metabolizes L-tyrosine by a pathway involving 3,4-dihydroxyphenyl-acetate as a key intermediate. p-Hydroxyphenylpyruvate is formed from tyrosine by an aminotransferase specifically requiring α-ketoglutarate for activity, and is then converted to p-hydroxyphenylacetate by an oxidative decarboxylation. p-Hydroxyphenylacetaldehyde is not an intermediate in the formation of p-hydroxyphenylacetate. Extracts of the bacterium oxidize 3,4-dihydroxyphenylacetate to δ-carboxymethyl-α-hydroxymuconic acid which, when supplemented with 2 mol of diphosphopyridine dinucleotide, results in the production of stoichiometric amounts of succinate and pyruvate.
ICMSF methods studies. IX. The influence of selective enrichment broths, differential planting media, and incubation temperatures on the detection of Salmonella in dried foods and feed ingredients
Authors: Gabis D. A. , Silliker J. H.
Published: April 2010

Ninety-eight dried foods and feed ingredients were analyzed for Salmonella using tetrathionate brilliant green (T) and selenite cystine (S) broths incubated at 35 and 43 °C. The four enrichment cultures for each sample were subcultured in duplicate onto brilliant green (BG), Salmonella–Shigella (SS), and bismuth sulfite (BS) agars, one plate of each being incubated at 35 °C, the other at 43 °C. Salmonellae were isolated from 44 of the 98 samples. Differences in the Salmonella recovery rates from the four selective enrichment conditions were not significant. However, there was a trend toward a higher proportion of Salmonella colonies on the selective media when the enrichment broths were incubated at 43 °C, although the differences were significant only with BG and SS subcultured from T. While the four enrichment systems were not significantly different, the trend toward a higher proportion of Salmonella colonies on the differential media subcultured from 43 °C enrichment broths indicates an advantage to incubation at the elevated temperature. Incubation of selective agars at 35 °C was best because at 43 °C Salmonella recovery was significantly reduced. Detection of salmonellae on BS was significantly better than on BG or SS.
Polarity in the exponential-phase Rhizobium japonicum cell
Authors: Tsien H. C. , Schmidt E. L.
Published: April 2010

Highly distinctive aspects of the exponential-phase Rhizobium japonicum cell were disclosed by means of thin sections, freeze etching, fluorescent antibodies, and ruthenium red staining. Polarity was expressed in the form of reserve polymer distribution near one end of the cell and as cytoplasmic localization near the opposite end. In addition, exocellular polysaccharide (EPS) accumulated preferentially around the cytoplasmic end, and the feature described previously as an "immunofluorescent polar tip" was seen clearly as an extracellular polar body (EPB) on the tip of the cell at the reserve polymer end. Compartmentalization of cytoplasm and reserves were consistent features of nearly all exponential cells of the two strains studied; strain 31, however, formed little EPS and had a high incidence of a large, tightly bound EPB, while strain 138 formed EPS extensively and had a low incidence of EPB. Extracellular polysaccharides of strain 138 reacted with soybean lectin in gel diffusion tests, so that the EPS seen in electron micrographs is tentatively considered to include the lectin-binding material. Extracellular polar bodies were accumulations of granular and fibrillar material with properties consistent with the presence of polysaccharide and lipopolysaccharide. The role of EPB in cell to cell attachment was confirmed by electron microscopy.
The cellulase system of a Cytophaga species
Authors: Chang William Tien Hung , Thayer D. W.
Published: April 2010

Cellulases (EC 3.2.1.4) of a Cytophaga species WTHC 2421 (ATCC 29474) were found in the soluble portion of the cell (the periplasm and the cytoplasm) and on the membrane. Cell-free cellulases were not found. Most of the carboxymethylcellulase activity associated with reduction of viscosity was membrane bound, whereas most of the carboxymethylcellulose (CMC) saccharifying activity was soluble. The CMC-saccharifying activity was increased 534 × by purification procedures which included ammonium sulfate precipitation and molecular exclusion chromatography with Sephadex G-75 and Biogel p-100. Periplasmic carboxymethylcellulase had a molecular weight of 6250 and cytoplasmic carboxymethylcellulase had a molecular weight of 8650. Analytical ultracentrifugation of the periplasmic carboxymethylcellulase (CMCase) indicated that it had a low molecular density. The chromatographic fraction containing periplasmic CMCase aslo contained enzyme activity against crystalline cellulose. The activity against crystalline cellulose was 238 × higher than the activity shown by the whole cell. The reaction of the enzyme with either CMC or dewaxed cotton produced only glucose. The enzyme was slightly inhibited by the presence of 0.01% (w/v) glucose, lactose, or cellobiose, but it was not affected by sucrose, and exhibited increased activity in the presence of xylose and fructose.
A rapid, simple method for staining bacterial flagella
Authors: Mayfield C. I. , Inniss W. E.
Published: April 2010

A simple modification of Gray's flagellar staining procedure is described. It can be used on air-dried smears or directly on wet mounts of motile bacteria. The stained bacterial flagella can be observed with phase-contrast or bright-field optics. No rigorous cleaning of slides, counterstains, or any washing procedures are required with the staining method, making it very suitable for routine examinations.
Carbon source dependent differences in the composition of the cell walls of the basidiomycete Picnoporus cinnabarinus
Authors: Cury J. A. , Amaral Déa
Published: April 2010

A wild-type monokaryotic strain of Picnoporus cinnabarinus grown on glucose produced shorter and thicker hyphae than cultures grown on acetate. Colonies from glucose media were smaller and more compact than acetate-grown colonies. Chemical and enzymatic analysis of the isolated cell wall of both morphological types showed that the amount of amino sugars and the ratio glucosamine:galactosamine were higher in the acetate-grown cells. This may be the cause of morphological differences observed.
Response of microbial populations in Arctic tundra soils to crude oil
Authors: Sexstone Alan J. , Atlas Ronald M.
Published: April 2010

Experimental crude oil spillages of 5 and 12 ℓ/m2 were established on the four major topographically distinguished soils of Arctic coastal polygonized tundra. The response of microbial populations to contaminating oil was found to depend on soil type and depth. Increases in numbers of heterotrophs were initially restricted to the top 2 cm of the soils. Increases in oil-degrading populations were found in oil-treated soils. Increases in microbial populations in subsurface soils paralleled downward migration of the oil. Some of the observed population increases probably resulted from input of plant residues and products from oil biodegradation.
Regulation of pyruvate kinases from Fusarium oxysporum
Authors: Zink M. W.
Published: April 2010

Two types of pyruvate kinases were found in Fusarium oxysporum. One type (inducible) was present mainly during the early stages of growth on glucose or sucrose and displayed Michaelis–Menten kinetics with respect to phosphoenolpyruvate and adenosine diphosphate. The major type (constitutive) was present under all conditions of growth and displayed in the absence of potassium ions, a sigmoidal substrate saturation curve when phosphoenolpyruvate was used as the variable substrate. In the presence of potassium ions the saturation curve for phosphoenolpyruvate exhibits a plateau at half-maximal velocity.The effects of various metabolites on the activity of the inducible and constitutive kinases were also studied. Fructose-1,6-diphosphate, cyclic AMP, acetyl Co A, tryptophan, and phenylalanine had no effect on the activity of the enzymes. Citrate was a potent inhibitor of the constitutive pyruvate kinase activity and increased the sigmoidicity of the saturation curve for phosphoenolpyruvic acid. In the presence of K+, the bimodal plot observed in the absence of citrate gradually changed to a hyperbolic shape as the concentration of citric acid was increased. In the presence of K+ and ADP as the variable substrate citric acid converted the hyperbolic plot to a sigmoidal one. Citrate had no effect on the inducible enzyme.
Influence of acetohydroxamic acid on experimental Corynebacterium renale pyelonephritis
Authors: Jerusik Russell J. , Kadis Solomon , Chapman Jr. Willie L. , Wooley Richard E.
Published: April 2010

The role of Corynebacterium renale urease in the establishment of pyelonephritis was studied by the oral administration of acetohydroxamic acid (AHA), a urease inhibitor, to experimentally infected rats. The bacteria were introduced by surgical insertion of a zinc disc containing 1 × 106 colony-forming units of C. renale into the urinary bladder whereas sterile discs were implanted in the bladders of the control animals. Daily administration of AHA via the drinking water did not halt the development of pyelonephritis. Larger doses, given by gavage, did accomplish this goal; that is, the pH of the urine was lowered, the number of colony-forming units of C. renale in the kidney was reduced drastically, and pyelonephritic lesions were observed in the kidney by light-microscopic examination. All experimental rats developed cystitis in varying degrees of severity. About 70% of the intact AHA given by gavage was excreted in the urine 24 h after administration of this compound. Rats implanted with a urease-negative mutant of C. renale displayed no signs of pyelonephritis but did develop cystitis.
Comparison of fatty acid composition of stable L-phase variants of Staphylococcus aureus induced by three different mechanisms
Authors: MacGee Joseph , Glotzbecker Cheryl , Watanakunakorn Chatrchai
Published: April 2010

The total saponifiable fatty acids of three stable L-phase variants of Staphylococcus aureus induced by cycloserine, methicillin, and lysostaphin were examined by gas-liquid chromatography. Five separate preparations of each of the three variants were examined. Twenty-nine fatty acids were identified. The fatty acid patterns of the three variants were very similar.
Concentric bodies in two species of the Loculoascomycetes
Authors: Samuelson Don A. , Bezerra Jose
Published: April 2010

Concentric bodies were found in vegetative and pycnidial cells of Podoxythium tricothecium and in ascostromal paraphyses of Rhytidhysterium rufulum, two representatives of the Loculoascomycetes. They averaged 185 nm in diameter in P. trichothecium and 255 nm in R. rufulum and consisted of three zones.
Purification and biochemical properties of Egtved viral RNA
Authors: Robin Jean , Rodrigue Alice
Published: April 2010

32P-labeled Egtved virus RNA was released from highly purified virus by phenol-SDS extraction. The single-stranded nature of the RNA was demonstrated by (1) its buoyant density of 1.69 g/cm3 in Cs2SO4, (2) its susceptibility to digestion by pancreatic ribonuclease in either 1 × SSC or 0.01 × SSC(standard saline citrate), (3) its base composition (29.3% C, 23.6% A, 14.5% U, 32.6% G).This Egtved virus is different from the other rhabdoviruses since the base composition of its genomic RNA is lower in its composition of A + U. Such a result could have possible taxonomic implications concerning the origin and evolution of Egtved Virus relative to the other known rhabdoviruses.
Metabolism of mandelic acid by Neurospora crassa
Authors: Rao D. N. Ramakrishna , Vaidyanathan C. S.
Published: April 2010

Preliminary studies on the metabolism of mandelic acid by Neurospora crassa reveal the operation of a pathway for its degradation which involves benzoyl formic acid, benzaldehyde, benzoic acid, 4-hydroxybenzoic acid, and protocatechuic acid as the intermediates. This pathway is different from that followed by bacterial systems and is the same as that observed in Aspergillus niger.
Protective effect of polymyxin B sulfate in experimental meningococcal infection in mice
Authors: Bannatyne Robert M. , Harnett Norma M. , Cheung Rose
Published: April 2010

The mouse model of intraperitoneal meningococcal sepsis was used to evaluate the antiendotoxic activity of polymyxin B sulfate independent of its antibiotic effects. Administered either before or after the infective challenge therapeutic doses of polymyxin B sulfate produced small but significant increases in survival over unprotected animals. These results also suggest that endotoxin contributes to the outcome in this variety of Gram-negative infection.
Nitrate-reductase electron-transport cofactors in Veillonella alcalescens
Authors: Ruoff K. L. , Delwiche E. A.
Published: April 2010

Studies on the effects of inhibitors of the nitrate-reducing activity of Veillonella alcalescens extracts suggest the participation of a naphthoquinone, a b-type cytochrome, and non-heme iron in electron transport to nitrate. A nitrate-reductase-deficient mutant displayed a longer doubling time and a decreased molar growth yield on nitrate media. This mutant was phenotypically restored by the addition of molybdate to the growth medium, giving evidence for the functioning of molybdenum in the nitrate-reductase enzyme of V. alcalescens.
The effect of Waring Blendor treatment on transformation in Bacillus subtilis
Authors: Weppner William A. , Clark Phillip O. , Leach Franklin R.
Published: April 2010

Treatment of competent Bacillus subtilis in a Waring Blendorfor 10 s increases transformability of the culture about twofold while reducing the attachment of DNA to competent cells by 80%. The effectiveness of attached DNA in producing transformants is increased 10-fold by this treatment. The uptake of transforming DNA into a DNase-resistant state is progressively reduced by 70% during a 120-s blending treatment. Blending for 30–45 s diminishes transformability to about 10% of the original nonblended value without affecting the viable cell titer. No effect is produced by 30 s of blending on transformability if the irreversible uptake of DNA has been completed. Thus, the inhibition occurs at an early step in the transformation sequence. Treatment of the competent culture for 60 s or longer in the Waring Blendor reduces both the number of transformants obtained and the total number of viable cells.
Vesicular-arbuscular mycorrhizae of Easter lily in the northwestern United States
Authors: Ames R. N. , Linderman R. G.
Published: April 2010

The vesicular-arbuscular (VA) mycorrhizal fungi of commercially grown Easter lily (Lilium longiflorum Thunb.) were studied. Soil and root samples were collected monthly from March through September 1975 from five fields in the coastal area of southern Oregon and northern California. Soil seivings were inoculated onto clover, onion, and lily to cause infections resulting in the production of many new mycorrhizal spores facilitating identification. Four VA mycorrhizal species were found: Acaulospora trappei, A. elegans, Glomus monosporus, and G. fasciculatus. All four VA species infected Easter lily, clover, and onion. Acaulospora trappei and G. fasciculatus were the most commonly isolated species from all five fields.Mycorrhizal infections in roots of field-grown lilies were sparse and presumably young in March and gradually increased in size and number until September when bulbs were harvested. Over 75% of each root system became infected with mycorrhizae in fields with all four fungal species, and those levels were reached by July. In fields with only two mycorrhizal species, usually 50% or less of each root system was infected, even by the end of the growing season.
Hyphal interference by Trametes hispida
Authors: Traquair James A. , McKeen Wilbert E.
Published: April 2010

The antagonistic activity of Trametes hispida Bagl. in dual culture with Hirschioporus species and other non-basidiomycetous fungi is interpreted as hyphal interference. Hyphae of T. hispida grow into and over colonies of sensitive fungi. Contact with hyphae of T. hispida results in cessation of growth and rapid necrosis of affected cells.Ultrastructural studies of the affected hyphae of Hirschioporus pargamenus (Fr.) Bond. &Sing. showed an early formation of extraplasmalemmal wall deposits, disruption of membrane systems, coagulation of cytoplasm, localized dissolution of walls, and loss of cell contents without penetration by the antagonist.
The effect of rifampicin on the developmental phases of germinating spores of Clostridum sp., MSp+
Authors: Hawirko R. Z. , Bhatnagar P. K. , Chung K. L. , Chow C. T.
Published: April 2010

The effect of rifampicin on the developmental phases of germinating spores of Clostridium botulinum, MSp+, has been studied. At sublethal concentrations of rifampicin (0.05 ng/ml) the time periods required for outgrowth and vegetative growth was significantly prolonged because of the inhibition of RNA and protein synthesis. However, rifampicin had essentially no effect on DN A synthesis or on subsequent spore formation. Chemical analyses showed that the amount of protein present in vegetative cells of the rifampicin-treated cultures was twice as great as in the untreated cultures but the total protein content of endospores was the same in both cases. It was revealed in ultrastructural studies of rifampicin (0.1 ng/ml) treated cultures, examined after 22 h, that septum formation and normal cell division of the emerging cell was blocked and a few cells showed constriction which produced one normal and one protoplast-like daughter cell.
Purification of infectious pancreatic necrosis (IPN) virus and comparison of polypeptide composition of different isolates
Authors: Chang N. , MacDonald R. D. , Yamamoto T.
Published: April 2010

Infectious pancreatic necrosis (IPN) virus was partially purified by freon extraction of infected CHSE-214 cells and concentrated by polyethylene glycol (PEG) precipitation of virus from the medium. Both methods resulted in virus concentrates that could be further purified by two CsCl gradient centrifugations with little loss of infectivity. A recovery of 80 to 100% of the virus infectivity was obtained and over 100-fold concentration of viral infectivity was achieved by these methods. This purification was used to compare 10 isolates of IPN virus with regard to their physiochemical properties by electron microscopy, buoyant density in CsCl, and sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis of the purified virions. Electron-microscopic observations showed that the virus isolates were identical in that they were isometric, hexagonal in profile, and had a particle diameter of 71 nm. The buoyant densities of the virus isolates in CsCl were found to be 1.33 g/ml. SDS-gel electrophoresis of the virus isolates revealed the presence of three polypeptides of molecular weight 50, 30, and 27 × 103 daltons designated as VP50, VP30, and VP27, respectively.
Restoration of virulence of axenically cultivated Entamoeba histolytica by cholesterol
Authors: Meerovitch E. , Ghadirian E.
Published: April 2010

The lost pathogenicity of two strains of Entamoeba histolytica, one isolated in 1924 and the other in 1967, grown in axenic culture for the past 5 and 6 years respectively, was restored by supplementing the culture medium with cholesterol through a number of transfers. The number of passages in the cholesterol-supplemented medium, necessary to restore a certain degree of pathogenicity of the two strains in hamsters, was proportional to the total time of in vitro cultivation of the strain, and not just the time of cultivation under axenic conditions. Pathogenicity, once restored, persisted for a long time after cholesterol treatment was stopped.