bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure and chemical composition of yeast chlamydospores of Aureobasidium pullulans
Authors: Brown Robert G. , Hanic Louis A. , Hsiao May
Published: February 2010

Cellular form in Aureobasidium pullulons can be partially controlled by nitrogen nutrition. Ammonium nitrogen supports a mixture of filamentous and yeastlike growth, whereas only a few filaments develop on nitrate nitrogen. On nitrate 97% of the cell material consists of a mixture of yeastlike cells and chlamydospores. Chlamydospores are produced on both nitrogen sources; however, with ammonium nitrogen chlamydospores occur in an intercalar position, whereas nitrate nitrogen supports development of chlamydospores as separate structures containing one, two, or occasionally three cells. This mode of production allows separation of yeast chlamydospores from other cell types and subsequent isolation of their cell walls. Yeast chlamydospores and filaments have an electron dense, melanin-rich, granular, outer cell-wall layer which yeastlike cells lack. This granular material is also found in cross walls of filaments and chlamydospores. Glucose is the main component of chlamydospore walls and accounts for 36% of the dry weight. Yeastlike cell walls contain only 13% glucose, but more mannose, galactose, and bound lipid. Most of the glucan portion of chlamydospore walls is insoluble in dilute alkali; methylation analysis indicates that this material contains linear chains of (1 → 3) and (1 → 6) linked glucose. About one residue in five forms a branch point having both (1 → 3) and (1 → 6) linkages.
Utilization of α-methyl-D-mannoside by Bacillus popilliae
Authors: Bhumiratana Amaret , Costilow R. N.
Published: February 2010

α-Methyl-D-mannoside (α-MM) was used by all acetate-oxidizing strains of B. popilliae tested at a growth limiting rate after a prolonged induction period. Those strains which did not oxidize acetate could not use α-MM for growth unless it was present at a high concentration. The period of induction was decreased, the rate of growth increased, and the extent of oxidation decreased as the α-MM concentration was increased. Theoretical levels of O2 uptake and CO2 evolution for the complete oxidation of the mannose moiety of α-MM were observed when the concentration of α-MM was low. Studies with resting cells and cell extracts demonstrated that an α-glucosidase was induced in B. popilliae by either α-MM or α-methyl-D-glucoside (α-MG). The enzyme was induced more rapidly by α-MG than by α-MM. Similarly, the ability of cells to oxidize α-MM was induced more efficiently by α-MG than by the mannoside. The data indicate that the hydrolysis of both α-MG and α-MM may be catalyzed by the same enzyme, but that the affinity for α-MG is much higher than that for the mannoside. The slow hydrolysis of α-MM by this enzyme is believed to account for the type of growth response observed.
Identification of a viral inhibitor in ground beef
Authors: Konowalchuk Jack , Speirs Joan I.
Published: February 2010

An inhibitor of coxsackievirus B5 was found in extracts of commercially ground beef; it resembled antibody in physical and chemical properties. Another inhibitor, found in a batch of fetal bovine serum, differed from the inhibitor in beef extract and specific coxsackievirus B5 antibody; it was destroyed at pH 3.0. Chemical bonds between virus and inhibitors in beef extract, fetal bovine serum, or specific antiserum against coxsackievirus B5 were formed during storage at 4 °C. The bonds were broken by treatment with hydrochloric acid at pH 3.0 for 1 h, releasing infectious virus. This finding may be of importance in the recovery of virus from ground beef.
A chemoautotrophic and thermophilic microorganism isolated from an acid hot spring
Authors: Brierley Corale L. , Brierley James A.
Published: February 2010

A pleomorphic, acidophilic, and chemoautotrophic microbe is described. The cell is bound by a membrane and a diffuse, amorphous layer. The isolate used either sulfur or iron as a source of energy. Morphological and nutritional similarities as well as corresponding thermophilic and acidophilic requirements suggest a relationship to Sulfolobus. The organism tolerates 80 °C for longer than 2 h, but heat resistance is not attributed to a bacterial spore. The maximum temperature for growth is 70 °C; the minimum about 45 °C.The DNA base composition is 57 ± 3 mole % GC. Yeast extract enhances growth of the isolate on iron and sulfur substrates, but does not significantly enhance the isolate's respiration rate on these same substrates.The isolate requires induction by sulfur or iron for maximum respiration on these substrates, respectively. Optimum oxidation of elemental sulfur occurred at pH 2.0 and gave a [Formula: see text] of 163; oxidation on iron gave a maximum [Formula: see text] of 879.
Effects of oxygen upon freeze-dried and freeze-thawed bacteria: viability and free radical studies
Authors: Cox C. S. , Heckly R. J.
Published: February 2010

Viability of freeze-dried Serratia marcescens 8UK was studied at 24.5 °C as a function of oxygen concentration and time. Results depended upon the source of the inoculum. Oxygen proved to be toxic and the kinetics (with respect to oxygen concentration) were first order at low oxygen concentrations and zero order at high oxygen concentrations. This indicates that the site for the action of oxygen can become saturated with oxygen. No simple relationship between viability and time was observed. Free radical studies were also made and showed that the detected free radicals were not involved in causing oxygen-induced loss of viability.The survival of Escherichia coli B frozen quickly and stored at −80 °C was found to be little, if at all, influenced by oxygen. Similar results were obtained with Serratia marcescens 8UK. Free radical studies were performed on E. coli B at −80 °C, but no free radicals were detected even after storing E. coli B for 30 days at −80 °C, −20 °C, and −10 °C. Under the last two conditions appreciable loss of viability occurred when E. coli B was frozen slowly.The results indicate that oxygen-induced loss of viability in freeze-dried and frozen and thawed Serratia marcescens 8UK and Escherichia coli B does not involve the formation of free radicals as has been suggested by other workers.
A comparative study of transformable and nontransformable isolates derived from two strains of streptococci
Authors: Pakula R. , Spencer L. R. , Anderson N. , Goldstein P. A.
Published: February 2010

From cultures of two strains of streptococci which were transformable to drug resistance with a very low yield of about 0.001%, efficiently transformable as well as totally nontransformable isolates were selected. Both kinds of isolates produced the competence factor and extracellular deoxyribonuclease. The nontransformable strains were lysogenic and produced bacteriophage after treatment with mitomycin C. The transformable ones were not lysogenic. Treatment of the latter strains with respective bacteriophages resulted in a loss of transformability. Determinations of deoxyribonuclease activity of all strains did not provide conclusive evidence as to the requirement for a deoxyribonuclease in transformation.
Influence of cell-wall thickness on cell division: electron microscopic study with Bacillus cereus
Authors: Chung K. L.
Published: February 2010

Bacillus cereus that had been exposed to chloramphenicol for 0 and 90 min synthesized walls whose thickness increased with time. These cells were washed and resuspended in fresh growth medium. Cell division was examined by electron microscopy. In untreated cells, a slight invagination of the cytoplasmic membrane with deposit of cross-wall material marked the onset of cell division. The cross wall grew inward until the septum was about [Formula: see text] completed. This was followed by splitting and bifurcation of the outer edge of the cross wall, which in turn separated the peripheral wall scars. Cross-wall penetration with further splitting continued until the daughter cells were completely partitioned. The peripheral wall scars that were located at the junction of peripheral and end walls at the time of cell separation indicated that the zone of cell division was probably not a region of active cell elongation. In cells treated with chloramphenicol for 90 min, cross-wall initiation and completion all occurred beneath a thickened peripheral wall. The circumferential portion of the peripheral wall at the zone of cell division appeared to be responsible for the hindrance of cell separation. This thick layer subsequently severed at three or four sites to allow the separation of daughter cells. For cells that had initiated cross-wall invagination at the time when chloramphenicol was added, accumulation of a large amount of cross-wall material at the zone of cell division was observed. Upon removal of the antibiotic, cells abandoned the old and initiated a new dividing site. For cells that had already completed cross-wall formation at the time of chloramphenicol treatment, the increase in wall thickness did not appear to interfere with cell separation. Models for the different stages of cell division in all these bacteria were presented.
Studies of the cell envelope of Vibrio parahaemolyticus
Authors: Deneke Carl F. , Colwell R. R.
Published: February 2010

Components of the cell envelope of Vibrio parahaemolyticus were investigated. Vibrio parahaemolyticus is an estuarine microorganism associated with diseases of marine and estuarine animals and seafood-borne enteritis in man. Purified lipopolysaccharide (LPS), isolated using a 45% phenol extraction procedure, was found to contain lipid A fraction to 27% of the LPS by weight. In the lipid A fraction, glucosamine was the only amino sugar to be present and a high molar ratio of phosphate to amino sugar (2.5:1) was noted. Two hydroxy fatty acids, hydroxydodecanoic and hydroxymyristic, were identified among the fatty acids by gas–liquid chromatography. A role of the lipopolysaccharides in the salt requirement of marine bacteria is suggested.
A study of the serotyping of Proteus rettgeri
Authors: Penner John L. , Hinton Norman A.
Published: February 2010

An approach to the serotyping of Proteus rettgeri through flagellar (H) and somatic (O) antigens is described. Major cross-reactions amongst strains with unlike H or O antigens were shown to be due to a common thermolabile capsular (or envelope) antigen. Absorption of antibodies against the thermolabile antigen resulted in specificity of the typing sera. Eighteen O, twelve H, and one K antigen are defined and their distribution among 83 strains is shown. Typing sera with reliable specificity may now be used in epidemiological investigations of infections with P. rettgeri.
Fate of the plasma membrane of Saccharomyces cerevisiae during cell rupture
Authors: Dubé J. , Setterfield G. , Kiss G. , Lusena C. V.
Published: February 2010

Intact and homogenized yeast cells were studied in thin sections in the electron microscope to determine the fate of the plasma membrane during fractionation. Intact cells possess a unit-membrane plasma membrane closely appressed to the cell wall. After even slight physical damage following limited homogenization in dilute buffer, the plasma membrane collapses away from the wall while the intra-cytoplasmic membranes (ER, vacuolar, nuclear, mitochondrial) dilate and vesiculate. With prolonged homogenization, the plasma membrane fragments and vesiculates and becomes indistinguishable from the remains of the other membranes. Washed wall fractions consist of wall fragments with entrapped vesicles derived from all cellular membranes. Exhaustive digestion of the wall fraction with snail gut enzymes liberates some of the trapped vesicles and results in an undigested, non-membranous, inner layer of wall partially contaminated with outer wall material. Polyacrylamide gel electrophoresis indicates that proteins of the wall "membranes" are partially of mitochondrial origin.
Estimation of nitrogenase in intact legumes
Authors: LaRue T. A. G. , Kurz W. G. W.
Published: February 2010

Intact legumes in pots can be assayed for nitrogenase by the acetylene reduction method. The assay does not involve destruction of or damage to the plant which can be assayed several times during its growth.
Ultrastructure and cell division of an oral bacterium resembling Alysiella filiformis
Authors: Kaiser Gary E. , Starzyk Marvin J.
Published: February 2010

Alysiella filiformis is commonly found on the epithelial cells of the oral cavity in rabbits. An ultra-structural study of these cells has shown A. filiformis attached by numerous slime appendages (setae) to the host epithelial cells. The organism possesses a multilayered cell wall 18–22 nm thick. Cell division occurs by constriction of the cytoplasm with concurrent septum formation initiating from the dense innermost layer of the cell wall. This is followed by thickening and delamination of the septum with subsequent invagination of the outer layers of the cell wall causing a partial cell separation. However, the cells of the typical trichomes are still held together by septal bridges. Mesosome-like structures were occasionally found and were often in the area of septum formation. All attempts to culture this organism in vitro were unsuccessful.
The release of alkaline phosphatase and of lipopolysaccharide during the growth of rough and smooth strains of Salmonella typhimurium
Authors: Lindsay Shelagh S. , Wheeler Bruce , Sanderson K. E. , Costerton J. W. , Cheng K.-J.
Published: February 2010

A rough strain of Salmonella typhimurium, which has a defect in the "inner core" region of its lipopolysaccharide, was shown to release more alkaline phosphatase into the medium during growth than did an isogenic smooth strain of the same organism. The pattern of enzyme release varied during growth in that early logarithmic phase cells retained alkaline phosphatase in their periplasmic space and at their cell surface while cells in later growth phases shed as much as 6% of their content of this enzyme into the medium. The reaction product localization technique used in this study enables us to assess enzyme production and localization in individual cells of a culture. The release of the enzyme was paralleled by a release of lipopolysaccharide from the cells. The released alkaline phosphatase shows a strong tendency to associate with purified phenol-extracted lipopolysaccharide.
Decreased sensitivity to polymyxin B in colicin K tolerant cells of Escherichia coli K-12 in the presence of colicin K
Authors: Mathieu L. G. , Legault-Hetu D.
Published: February 2010

Cells refractory to the lethal effect of colicin K were selected from a sensitive Escherichia coli K-12 strain. They could still be lysed by bacteriophage T6 which is thought to share with colicin K common receptor sites on the bacterial cell wall. Incubation of these cells for 30 min in a colicin K preparation considerably reduced its subsequent activity on the sensitive parent strain. When these tolerant cells were exposed to polymyxin B in the presence of colicin K, the lethal activity of the polymyxin was decreased significantly as compared with that exerted by the antibiotic in the absence of colicin K. In the colicin K sensitive wild strain, the combined lethal effect of the bacteriocin and of the antibiotic was not smaller than that of either inhibitor alone. Examination with the fluorescence microscope of cells stained with acridine orange showed that colicin K tolerant cells incubated with polymyxin B had undergone greater morphological changes than similar cells treated with polymyxin B in the presence of colicin K. Leakage of materials absorbing at 260 nm was greatest for the cells exposed to polymyxin B alone. The results suggest that in colicin K tolerant cells of E. coli derived from a sensitive strain, the bacteriocin might compete with polymyxin B for sites of attachment on the bacterial cell wall or mask some of the envelope phospholipids which are believed to react with polymyxin B.
Alcohol dehydrogenase activity in Rhodotorula glutinis
Authors: Woscinski Casimir J. , McClary Dan O.
Published: February 2010

Whole-cell extracts of Rhodotorula glutinis grown on yeast extract – glucose medium contained minute quantities of NAD-dependent alcohol dehydrogenase and cinnamyl alcohol dehydrogenase. Significantly greater quantities of these enzymes, as well as an NADP-dependent alcohol dehydrogenase were contained by cells grown on the same medium with ethanol substituted for glucose as the growth substrate. Although the [Formula: see text] on ethanol of whole cells grown in ethanol medium was more than triple that of cells grown in glucose medium, there was no significant difference in the [Formula: see text] on glucose of whole cells grown in glucose or in ethanol medium. Thermal inactivation studies revealed that the NADP-dependent alcohol dehydrogenase was relatively heat-stable as compared with the NAD-dependent alcohol dehydrogenase. Gel column electrophoresis revealed three active bands of alcohol dehydrogenase activity which were identified as NAD-dependent alcohol dehydrogenase, NADP-dependent alcohol dehydrogenase, and cinnamyl alcohol dehydrogenase. The NAD- and NADP-dependent enzymes, particularly the latter, were active on higher alcohols but not on methanol.
The effect of cold shock on the blue-green alga Anacystis nidulans
Authors: Jansz E. R. , Maclean F. I.
Published: February 2010

We have investigated the known susceptibility of the blue-green alga Anacystis nidulans to cold shock. After suspensions of the organism were exposed to temperatures of 0°–3° for 15 min, viability was reduced to about 2% and the photosynthetic rate to about one third. Resistance to this effect increased with age of the culture from which the cells were harvested. Polarographic measurements showed that the decline in photosynthesis was complete within a few minutes after removal from the cold, and autoradiography showed that the decline was distributed among all the cells in the suspension. The short-term 14CO2 fixation products in cold-shocked and control cells differed only in amount and the 14CO2 fixed/O2 evolved during photosynthesis was the same in control and cold-shocked cells. Cold shock also caused the loss of some of the diffusible material from the cell; the loss was rapid but did not continue beyond about one quarter of the diffusible C and P; intracellular glutamate was lost to the extent of 50–80%. It is suggested that cold shock affects the limiting membrane of the cell and that this causes cell death but it is uncertain whether it is also responsible for the decline in photosynthesis.
The flavin content of a hydrocarbon-utilizing bacterium
Authors: Roy Marie Lessard , Wayman Morris
Published: February 2010

A hydrocarbon-utilizing yellow-orange bacterium AK-19 of the genus Arthrobacter isolated in this laboratory was grown on n-butanol and the concentration of total flavins in an aqueous extract was determined by the lumiflavin fluorescence method. Two of the flavins present were identified as riboflavin and flavin adenine dinucleotide by paper chromatography. The concentration of each flavin was measured separately and found to be 0.6 μg and 18.6 μg per gram of dry weight of organism, respectively. The absorption spectrum of the extracted flavin adenine dinucleotide was measured.
The formation of homogentisic acid from phenylacetic acid by an Aspergillus sp.
Authors: Ueno Teruo , Yoshizako Fumiki , Nishimura Atsuo
Published: February 2010

Homogentisic acid was verified as one of the intermediates of phenylacetic acid metabolism by an Aspergillus species identified as a strain of A. fumigatus, using a replacement culture technique. o-Hydroxyphenylacetic acid was also detected in the culture fluid.
Derepression of a proline transport system in Staphylococcus aureus
Authors: Obbink D. J. Groot , Campbell J. J. R.
Published: February 2010

Staphylococcus aureus ATCC 6538P is auxotrophic tor proline. Under conditions of proline starvation, the organism synthesizes a transport system thus greatly increasing the rate of transport of proline into the cell. The proline transport systems of both the starved and unstarved cells were shown to be enzymatic, energy dependent, and specific for L-proline. Protein synthesis was required for derepression, and when the cells were fully induced, the organism established a non-exchangeable pool for proline, whose maintenance was dependent on protein synthesis. It is proposed that this transport system serves as a scavenging mechanism when the organism is in an environment deficient in proline.
Column variation affecting a pyrolysis–gas–liquid chromatographic study of strain variation in two species of Nannizzia
Authors: Sekhon Awatar S. , Carmichael J. W.
Published: February 2010

Variation in the pyrochromatograms of different strains of the same species was investigated using five different isolates of Nannizzia fulva and nine single-ascospore isolates derived from a mating of two N. cajetani strains. The colonies of the N. cajetani isolates differed markedly from each other in pigmentation and texture. Their pyrograms also varied, but the variation between strains was small compared with the difference between the two species. The differences between strains were not correlated with mating type.Pyrograms of one of the N. cajetani strains were prepared using newly packed columns. These pyrograms yielded a cluster that was somewhat distant from the other N. cajetani strains.
Glucose flux at the sediment–water interface of Toronto Harbour, Lake Ontario, with reference to pollution stress
Authors: Wood L. W. , Chua K. E.
Published: February 2010

Cycling of glucose at the sediment–water interface was determined through coupling measurement of natural substrate concentrations with heterotrophic uptake by the natural microbial communities in the sediment and in the water column. The same general pattern was found for both polluted and less polluted parts of Toronto Harbour, so that other labile organic species possibly have similar cycles. Velocity of uptake of glucose (flux) and turnover time showed no relationship to either substrate concentration or total organic matter of the sediments. Activity in the water column could be supported to a major extent by sediment export of substrate by turbulent diffusion. Sediment activity must be supported by particulate sedimentation and hydrolysis of large organic molecules, which may be aided by the macrobenthic community. Pollution stress apparently alters the catabolism of the substrate. The observed substrate concentrations may reflect a minimum of residual concentration, below which the microbial community has difficulty in taking up the substrate.
A temperature-sensitive glycyl-transfer ribonucleic acid synthetase mutant of Escherichia coli
Authors: Roback E. R. , Friesen J. D. , Fill N. P.
Published: February 2010

A method of selecting temperature-sensitive mutants of Escherichia coli which makes use of a double temperature shift combined with suicide as a result of incorporated 3H-uridine is described. One mutant selected in this way shows restricted growth at 42 °C resulting from early inhibition of protein and ribonucleic acid (RNA) synthesis. In vitro assays of aminoacyl-transfer RNA synthetase activity indicated a complete absence of active glycyl-transfer RNA synthetase in the mutant. This enzyme activity in the mutant was distinguishable from the wild type by its rapid inactivation at 28 °C in cell-free extracts. Infection of the temperature-sensitive mutant with bacteriophage T4 did not alter the heat-sensitivity of the mutant enzyme. The mutation is 72% cotransducible with the xyl locus.
Purification and some properties of the glutamate dehydrogenase of Salmonella typhimurium
Authors: Coulton J. W. , Kapoor M.
Published: February 2010

NADP-specific glutamate dehydrogenase (GDH) from Salmonella typhimurium was purified 190-fold by heat treatment, ammonium sulfate fractionation, DEAE-Sephadex chromatography, reverse ammonium sulfate fractionation, and gel filtration. The enzyme proved to be stable to 55 °C, and displayed a pH optimum at 8.6 in the amination reaction. The sedimentation coefficient of GDH, as determined by sucrose density gradient centrifugation, was about 10.3 S. From gel filtration chromatography, the molecular weight and Stokes' radius for the enzyme were estimated at 280 000 daltons and 54 × 10−8 cm, respectively. Unusual resistance was displayed by the enzyme to high concentrations of the protein denaturants, urea, SDS, and guanidine hydrochloride.
Studies on the kinetics and regulation of glutamate dehydrogenase of Salmonella typhimurium
Authors: Coulton J. W. , Kapoor M.
Published: February 2010

A 190-fold purified preparation of NADP+-specific glutamate dehydrogenase of Salmonella typhimurium was used for the determination of kinetic parameters of the substrates, NADPH, NH4+, and α-ketoglutarate, in the direction of glutamate synthesis, and NADP+ and glutamate in the reverse direction. The kinetic constants determined from this study suggest a biosynthetic role for the enzyme. Based on an analysis of the data derived from initial velocity and product inhibition studies, the reaction mechanism was postulated to be ordered Ter Bi with NADPH as the first substrate to bind in the forward direction, and NADP+ binding first in the reverse direction.Of the several metabolites tested for a possible function in the regulation of GDH activity, only L-malate and L-glutamine appeared to exert an appreciable influence on the enzyme. ATP and AMP at a concentration of 0.8 mM were found to enhance GDH activity by 68% and 6%, respectively, but at high concentrations, both the adenine nucleotides proved to be inhibitory.
Biophysical examination of the cell wall of a gram-negative marine pseudomonad. The effects of various treatments on the isolated double-track layer
Authors: Forge A. , Costerton J. W. , Kerr K. Ann
Published: February 2010

The isolated double-track layer of a gram-negative marine pseudomonad was subjected to a number of treatments designed to extract or to digest either phospholipid or protein. Extraction with chloroform–methanol caused aggregation and disruption of the double-track vesicles, a loss of the cleavage plane in frozen preparations, and a disappearance of the ring-like X-ray diffraction pattern which indicates side-by-side packing of the hydrocarbon tails of the phospholipids. Digestion with phospholipase-C, following ethylenediaminetetraacetate (EDTA) treatment, had the same effects except that the diglycerides freed by the action of the enzyme formed paracrystalline lamellar aggregates. This suggests that phospholipids are very important to the structural integrity of the double-track layer, that the layer of phospholipids is centrally located, and that this component of this membrane-like structure is responsible for the X-ray diffraction pattern produced by this material.Protein depletion by urea treatment or by pronase digestion causes increased aggregation of vesicles but these structures are not significantly disrupted, the cleavage plane is present in a stronger form in frozen material, and the X-ray diffraction pattern is unchanged. This suggests that proteins are superficially located and not as important as phospholipids in the structural integrity of this layer.The effects of protein depletion and of phospholipid depletion on the double-track layer are very similar to the effects of the same treatments on membranes, which supports the suggestion that the double-track layer has a membrane-like molecular architecture. The suggestion that this layer constitutes the barrier layer in the gram-negative cell wall is supported by our observations that sodium lauryl sulfate (SLS), EDTA, and polymyxin, which affect the penetrability of the cell wall of whole cells, have been shown to affect the molecular architecture of the isolated double-track layer used in these studies.
Isocitrate supported nitrogenase activity in Gloeocapsa sp. LB 795
Authors: Gallon J. R. , Kurz W. G. W. , LaRue T. A.
Published: February 2010

A system consisting of isocitrate, NADP, and ferredoxin can supply reducing power for acetylene reduction in broken-cell preparations of Gloeocapsa sp. LB 795. It is suggested that this system plays a physiological role in supporting nitrogen fixation, at least under conditions unfavorable for the photochemical generation of reductant.
Influence of sulfite on growth, slime, and fluorescent pigment formation by Pseudomonas aeruginosa
Authors: Palumbo Samuel A.
Published: February 2010

Substitution of sulfite for sulfate in the defined pyocyanine medium of Frank and DeMoss 1959 allowed formation of fluorescent pigments and slime by Pseudomonas aeruginosa NRRL B-4014. This formation of fluorescent pigments was both pH and iron dependent. The unadjusted medium (pH 8.25) containing sulfite and Fe3+ allowed both growth and fluorescent pigment formation. Growth and fluorescent pigment formation were observed from a pH of 9.0 down to a pH of 7.5. At pH 7.5, the concentration of HSO3− is 6 × 10−4 M, and this ion appears to be the active agent in inhibiting growth below pH 7.5. When the medium was adjusted to pH 7.0, neither fluorescent pigment formation nor growth was observed. The acid used for pH adjustment did not influence the minimum pH for growth. In the presence of small amounts of iron (ca. 1 × 10−6 M Fe3+), the organism shifted from a blue to a yellow-green fluorescent pigment. Cultural conditions such as temperature and nutrients which supported growth also supported slime formation as well as fluorescent pigment formation.
A study on phagocytosis of radio-labeled Staphylococcus epidermidis and on structural events during intracellular degradation
Authors: DeVoe I. W. , Storm D. W. , Gilchrist J. E.
Published: February 2010

A simplified system has been used to study the events during and after the in vitro ingestion of Staphylococcus epidermidis by mouse peritoneal polymorphonuclear leucocytes (PMN's). 14C-labeled bacteria were incubated with PMN's in phosphate-buffered, physiological saline without the addition of divalent cations or serum. PMN's appeared to be saturated within 15 min after having each engulfed about nine bacteria (on the average).Electron micrographs of thin sections from specimens taken after bacteria and PMN's had been incubated together for 15 min revealed intracellular staphylococci in various states of degradation. The fragmentation of the cytoplasmic membrane was apparently one of the early events in cell degradation. Several other morphological events were also observed in disintegrating cells, e.g. agglomeration of the cytoplasm; loss of cell-wall rigidity, an apparent digestion of the cell wall from the outside; and the release of membrane vesicles into the phagocytic vacuole.
Double-membraned vesicles in Geotrichum candidum
Authors: Steele S. D.
Published: February 2010

Ultrastructural studies have demonstrated the presence of double-membraned vesicles in Geotrichum candidum Link. These vesicles were found close to the cell wall and were associated with invaginations of the plasmalemma. The role of such vesicles is discussed.
Glucose utilization dependence on preferred carbon-source growth in an Arthrobacter sp.
Authors: Sokol R. A. , Klein D. A.
Published: February 2010

Arthrobacter sp., ATCC 25581, is incapable of glucose utilization except diauxically following growth on a preferred carbon source such as succinate. This phenomenon appears to be a novel mixed substrate utilization relationship.
Physiological changes following the breaking of dormancy of Saccharomyces cerevisiae ascospores
Authors: Rousseau Paul , Halvorson Harlyn O.
Published: February 2010

Optimal conditions have been defined for obtaining a synchronously germinating ascospore population of Saccharomyces cerevisiae. A rapid response was elicited when a yeast spore suspension was incubated in a nutritionally sufficient medium supplemented with glucose in a pH range of 5.4 to 8.2, and aerated at 30 °C. Lipids were used mainly during the swelling phase of the spore outgrowth. Respiratory studies revealed a burst of CO2 evolution 15 min after the onset of germination, and 3 h later a break in the rates of CO2 production, O2 consumption, and glucose uptake. During germination the pH of the medium decreased. These results suggested shifts in metabolism during germination and outgrowth of yeast spores.
Reversible heat injury in the marine psychrophilic bacterium Vibrio marinus MP-1
Authors: Griffiths Robert P. , Haight Roger D.
Published: February 2010

A modification of the double-medium technique of Iandolo and Ordal (1966) was used to study heat injury in the obligately psychrophilic marine bacterium Vibrio marinus MP-1. Results using this technique demonstrated that heated cell suspensions contained a mixed population of uninjured, reversibly injured, and irreversibly injured (killed) cells. The age of the culture, temperature, and length of heating time influenced the ratio in the population of the various types of cells. The repair process of reversibly injured cells was affected by the surface area-to-volume ratio of the medium used to support repair.
Specific identification of enteroviruses by immuno-electron microscopy using a serum-in-agar diffusion method
Authors: Anderson Nan , Doane Frances W.
Published: February 2010

Rapid type-specific identification of enteroviruses was performed by immuno-electron microscopy on crude cell-culture isolates, using an agar-diffusion technique in which the typing sera were incorporated in the agar. Seventeen virus samples which consisted of 11 different enterovirus types showed no cross-reaction when tested against 15 enterovirus antisera. Specific virus identification, based on the presence of visible antigen–antibody complexes, was not dependent on optimal dilutions of antiserum, but could be achieved with a variety of dilutions. The minimum amount of virus that could be detected by this method was about 100 times less than that detectable by electron microscopy in the absence of antiserum.
Production, isolation, and antifungal activity of scytalidin, a metabolite of Scytalidium species
Authors: Stillwell M. A. , Wall R. E. , Strunz G. M.
Published: February 2010

The production and isolation of scytalidin, a recently reported metabolite of Scytalidium sp., are described. The compound was found to be relatively active in vitro against many fungi associated with stain and decay of pulpwood chips in outside storage and decay in the roots and butts of conifers. Other fungi associated with diseases of trees and deterioration of forest products were also found to be sensitive to scytalidin. Seed germination tests indicated relatively low phytotoxicity.
Métabolisme de l'asparagine et de l'acide aspartique chez Corynebacterium sepedonicum (Spieck. et Kott.) Skapt. et Burkh.
Authors: Boucher Yvan , Paquin Roger , Willemot Claude , Lachance Robert A.
Published: February 2010

not available
Budding bacteria of the Pasteuria–Blastobacter group
Authors: Staley James T.
Published: February 2010

Two strains of ovoid budding bacteria have been isolated from peptone enrichment cultures from a creek and lake. The cells of both strains attach to organisms and inanimate substrata by holdfast structures located at the narrow poles of the cells and produce buds at or near the opposite, wider pole of the cell. Newly formed buds are motile by monotrichous flagella inserted at or near the wider pole of the cell. Although these strains could be included as the first isolates of either the genus Pasteuria or Blastobacter, the author has concluded that the one viable strain be regarded as the type strain of Pasteuria ramosa Metchnikoff 1888.
The adsorption of the Pseudomonas aeruginosa filamentous bacteriophage Pf to its host
Authors: Bradley David E.
Published: February 2010

Little is known about the filamentous Pseudomonas aeruginosa bacteriophage Pf and no information is available concerning the nature of its receptors on the host organism. In view of the fact that the filamentous coliphages infect by means of sex pili, it might be expected that Pf uses as receptors the polar pili present on its host. This paper describes experiments designed to establish whether or not this is the case. It is shown that pilus-free mutants of the host organism are resistant to Pf and that the phage does not adsorb to them. Electron microscopy, using specific antibody labeling to distinguish pili from phage, shows that the Pf filaments are attached preferentially at the pole of the cell after adsorption, the full 1950 nm length remaining visible. It is suggested that the virions adsorb to the tips of the pili which then retract pulling the Pf filaments until they contact the cell wall. It is also found that Pf-infected cells produce their progeny by extrusion from the poles without lysis.
Characterization and partial purification of β-hydroxybutyrate dehydrogenase from sporulating cells of Bacillus cereus T
Authors: Thompson E. D. , Nakata H. M.
Published: February 2010

A soluble NAD+-dependent β-hydroxybutyrate (βHB) dehydrogenase was shown to appear 3 to 4 h after the onset of sporulation of Bacillus cereus T. The enzyme was stable in Tris-chloride buffer when frozen, but required 0.05 to 0.1 M of MgCl2 or other divalent cation such as Mn2+, Ba2+, or Ca2+ for stability at 4C. In the presence of phosphate buffer or EDTA, the enzyme lost all activity within 2 min. βHB dehydrogenase was partially purified and shown to have a molecular weight of about 93 000, pH optimum of 8.0 in 0.1 M Tris-chloride buffer, Michaelis constants, Km, of 2.3 × 10−3 M for β-hydroxybutyrate and 9.5 × 10−4 M for NAD+, and was inhibited 40% by 1 × 10−3 M p-hydroxymercuribenzoate. The enzyme from B. cereus T was compared in these respects with βHB dehydrogenases isolated from several non-sporeforming bacteria.
Inactivation of Mycoplasma in seed virus stocks using gamma radiation
Authors: Polley J. R. , Fanok A. G.
Published: February 2010

A method was developed for the elimination of viable Mycoplasma in reference seed virus stocks. It was found that various species of Mycoplasma (such as M. pneumoniae, M. arthritidis, M. hominis, M. salivarium, M. orale types I and II, M. meleagridis, and several unidentified species isolated from tissue cultures) were inactivated more rapidly by gamma radiation than all viruses tested. By the use of selected radiation doses, high concentrations of Mycoplasma species could be inactivated in virus suspensions of polioviruses types I and III, coxsackie viruses types A-7, A-9, B-3, and B-6, echoviruses types 1, 9, 12, and 20, herpes simplex, rubella, measles, and adenovirus type 7a, without inactivating all viable virus. After irradiation, the remaining viable virus could be propagated as well as the original strain and showed no change in reactivity with homologous or heterologous antisera. After storage for 2 months at −70 °C, the irradiated virus showed no decrease either in viability or in specific reactivity. By this method, reference seed virus stocks could be prepared free of viable Mycoplasma species, without dependence on tissue cultures free of Mycoplasma.
Carbon dioxide fixation by Veillonella parvula M4 and its relation to propionic acid formation
Authors: Ng Stephen K. C. , Hamilton Ian R.
Published: February 2010

The effect of carbon dioxide on propionate formation during lactate and pyruvate metabolism by intact cells and cell-free preparations of Veillonella parvula M4 was examined. While the overall rate of lactate-U-14C degradation by intact cells was not altered, concentrations of unlabeled CO2 (to 50%) stimulated the evolution of 14CO2, and increased the absolute quantity of the propionate formed, while decreasing its specific activity. Acetate production from the labeled lactate, however, was not affected. Furthermore, propionate formation was not dependent on the presence of CO2 in the gas phase. The principle product of pyruvate-3-14C metabolism by extracts of the organism was acetate, although minor amounts of labeled propionate were also formed. Small quantities of oxaloacetate were detected during this metabolism by direct enzymatic assay and by separation of its hydrazone by thin-layer chromatography. Dialyzed crude extracts of the organism, treated with protamine sulfate and charcoal, were shown to catalyze the formation of oxaloacetate from pyruvate and CO2 in the presence of ATP when assayed both enzymatically with malic dehydrogenase and NADH, and with pyruvate-3-14C. This CO2-fixing activity could be attributed to pyruvate carboxylase, since the activity was Mg2+-dependent, was inhibited by avidin and aspartate, and was stimulated by biotin and CoA. Furthermore, the same extract preparation was capable of converting pyruvate-3-14C and CO2 to malate in the presence of NADH and NADPH indicating the presence of malic enzyme in the organism; this activity was confirmed by spectrophotometric means. As is the case with V. alcalescens, dialyzed extracts of V. parvula M4 catalyzed the exchange reaction between the carboxyl group of pyruvate and CO2; this exchange activity was stimulated by ATP.
Antibiotic sensitivity of Clostridium perfringens and L-forms of C. perfringens induced by bacteriocin
Authors: Mahony D. E.
Published: February 2010

Ninety strains of Clostridium perfringens were tested with 8 to 10 different antibiotics by the Kirby-Bauer disc method for determining bacterial sensitivity. The results of these tests were compared with previously established bacteriocin sensitivities of these strains. Twenty-three of the above strains were converted to L-forms by growth in soft agar overlays on plates containing a bacteriocin of C. perfringens and these were tested with eight antibiotics. A marked resistance to penicillin, ampicillin, and methicillin was apparent in the L-form growth as compared to the degree of sensitivity obtained with the normal growth of C. perfringens.
The immunological analysis of soluble human leukemia associated antigens
Authors: Yong David C. T. , Kwapinski J. B. G.
Published: February 2010

Soluble antigens were obtained from the liver of myelocytic and congenital human leukemia cases by hyaluronidase treatment of tissues, extraction with 1 M KCl, and purification by isoelectrofocusing and prolonged gel electrophoresis. The extracts and one isoelectrofocusing fraction obtained from organs of myeloid leukemia, but not those from lymphoid leukemia, reacted with an antiserum produced against the pI 4.85 isoelectrofocusing fraction. A single antigen, which was purified additionally by a prolonged gel electrophoresis, and migrated slightly towards the cathode, was found to react with the rabbit antisera produced against leukemic fractions, absorbed with normal tissues. This antigen was identified as a galactopolypeptide.
Use of coliphages as indicators of water pollution
Authors: Hilton Mary C. , Stotzky G.
Published: February 2010

The feasibility of using coliphages as indicators of sewage pollution was investigated. Standard coliform determinations (MPN) were also made to compare fluctuations in coliforms with fluctuations in their obligate parasites. No consistent relationship was found between coliform and coliphage levels. The results did indicate, however, that the enrichment method of phage assay could be used for the detection in water of low levels of phages active against specific host bacteria.
Fine structural observations of Desulfovibrio desulfuricans
Authors: Hammill Terrence M. , Germano Geno J.
Published: February 2010

Glutaraldehyde-fixed, platinum-carbon-shadowed whole mounts, and ultrathin sections of glutaraldehyde-OsO4-fixed cells of Desulfovibrio desulfuricans were observed by electron microscopy. The preparations demonstrated a typical Vibrio form with a single polar flagellum. The cell envelope and the formation of external blebs were shown to be similar to other gram-negative bacteria. The protoplast, apparently devoid of mesosomes or other membranous structures, was densely packed with ribosomes and contained a fibrous nucleoid. A specialized region near the flagellar end of the cell was commonly observed and termed the basal apparatus. Cell division appeared to be by constriction.
Thermal stability of ribosomes from a thermophilic and a mesophilic fungus
Authors: Miller H. M. , Shepherd M. G.
Published: February 2010

Ribosomes and ribosomal subunits from the thermophile Penicillium duponti were found to be more thermostable than the corresponding particles from the mesophile Penicillium notatum. The thermostability of the ribosomes from both organisms was dependent on magnesium ion concentration. The dissociation of the 80-S ribosomes into 60-S and 40-S subunits occurred at higher magnesium ion concentrations for the mesophile than the thermophile.
Endotoxin sensitivity of inbred mouse strains
Authors: Vas Stephen I. , Roy Raymond S. , Robson Hugh G.
Published: February 2010

Inbred mouse strains show characteristic susceptibility to S. typhimurium infections. The sensitivity of the same strains to endotoxin is not parallel. While C3H/He J and C57B1/6J mice were highly susceptible to infection they showed more resistance to purified endotoxin than A/J, a mouse strain relatively resistant to infection. These findings suggest that the death of mice during S. typhimurium infection is not due only to toxic effects of its lipopolysaccharide.
Effect of eight fungicides on microbial activities in soil as measured by a bioassay method
Authors: Chinn S. H. F.
Published: February 2010

Eight fungicides used in soil treatments were assayed for their effect against three species of bacteria, two of actinomycetes, and three of fungi at intervals over a 32-week period. Methylmercury dicyandiamide (MMDD) was the only fungicide that showed some inhibitory effect at 1 ppm. MMDD and Hoe 2874 were the most effective fungicides followed by Chemagro B1843, thiram, and maneb in decreasing order of effectiveness. Captan with low solubility and two insoluble fungicides showed little or no activity. No fungicide at 1 or 10 ppm persisted for over 3 weeks. At 100 and 1000 ppm some fungicides persisted for periods extending beyond 32 weeks. The eight fungicides differed both quantitatively and qualitatively in their ability to inhibit or stimulate the various test organisms. The method is described and the effect of fungicides in soil treatment on the general microflora besides the soil pathogens is discussed.
Ultrastructural changes in the midgut epithelium of an elaterid larva (Coleoptera) infected enterically with Pseudomonas aeruginosa
Authors: Zacharuk R. Y.
Published: February 2010

Soil bacteria enter the digestive tract of wireworms at ecdysis through the dorsal exuvial split and ecdysial space. Pseudomonas aeruginosa, a potential pathogen of insects, multiplies in the enteron, but many are killed within it. The mucopeptide layer of the bacterial cell wall is affected early in the degenerative process.A surface epithelial mucoid layer provides a temporary protective barrier for the midgut epithelium against the bacteria. The bacteria affect the fine structure of the host midgut epithelium in three primary ways. (1) The cells take up and retain fluids in the cytoplasm and membrane-bound vacuoles to the point of apical rupture; the selective permeability of the membranes of the cell and vacuoles appears to be affected. (2) The surface mucoid covering is degraded, the exposed plasma membrane is disrupted, and a lytic erosion of the exposed cytoplasm occurs opposite bacterial colonies. Lesions thus form in the midgut epithelium, and could lead to perforation of the wall at these points. (3) Pathological changes occur in various cell organelles, the most striking of which are an increase in abundance of rough endoplasmic reticulum (RER) and cytoplasmic ribosomes, and a transposition of membrane material from mitochondria and Golgi complexes to RER. The functional implications of these pathological changes in fine structure are discussed.