bluuebunny/crossref_metadata_2025 huggingface dataset:
Cell-free, protein-synthesizing system of photosynthetic and heterotrophic Rhodospirillum rubrum
Authors: Chow C. T.
Published: April 2010

An active in vitro protein-synthesizing system has been developed from Rhodospirillum rubrum grown under either photosynthetic or heterotrophic conditions. A protease activity has been found in both of these systems, and this activity can be readily inactivated by treating the cells with KCl and phenylmethyl sulfonylfluoride. The difference in protein-synthesizing activity between the photosynthetic and the heterotrophic systems has been tested in regard to the requirement of various chemicals and the response to protein synthesis inhibitors or various chemical compounds. It has been concluded that only minor differences in protein-synthesizing activity exist between these two systems.
Comparison of the cell envelope proteins of Micrococcus cryophilus with those of Neisseria and Branhamella species
Authors: Russell R. R. B. , McDonald I. J.
Published: April 2010

In an attempt to elucidate the relation between Micrococcus cryophilus, Neisseria caviae, Neisseria ovis, and Branhamella catarrhalis, fractions derived from outer membranes of a strain of each organism were examined for protein composition by SDS – polyacrylamide gel electrophoresis. Micrococcus cryophilus outer membrane protein showed extensive similarities to that of N. ovis and contained a heat-modifiable protein which behaved almost identically with the corresponding bands previously shown to exist in N. caviae and N. oris. Branhamella catarrhalis protein was distinctly different from those of M. cryophilus and the two 'false neisserias' N. caviae and N. oris.
β-Xylosidases in the yeast Cryptococcus albidus var. aerius
Authors: Notario V. , Villa T. G. , Villanueva J. R.
Published: April 2010

β-Xylosidase activity has been detected in cell-free extracts and in culture fluids when Cryptococcus albidus var. aerius was grown on glucose as the sole carbon source. The enzyme appears to be constitutive. Mild acid treatment of whole cells suggested that the total activity is located in the periplasmic space and some experiments indicated that it is partially associated with the cell walls. DEAE-Sephadex A50 chromatography has shown that there are two different forms of β-xylosidase in the cell-free extracts, but only one form is present in the supernatants of culture.
The isolation of Vibrio parahaemolyticus and related vibrios from moribund aquarium lobsters
Authors: Brinkley A. W. , Rommel F. A. , Huber T. W.
Published: April 2010

Vibrios were isolated in pure culture from the hemolymph of 7 out of 28 dead or dying aquarium lobsters which had been acclimated to 20–22 °C. One isolate was identified as Vibrio parahaemolyticus, one as a related marine Vibrio (probably V. marinus), and five as Vibrio alginolyticus. No isolates of halophilic Vibrio species were made from healthy lobsters using thiosulfate citrate bile salts sucrose agar (TCBS).
Purification of Oidiodendron kalrai proteases
Authors: Cino P. M. , Tewari R. P.
Published: April 2010

Oidiodendron kalrai yeast-phase cells demonstrate proteolytic activity. Some of the proteolytic enzymes of the crude extract were purified by a combination of ammonium sulfate precipitation, Sephadex G-200, and diethylaminoethyl (DEAE) cellulose column chromatography. At least six proteins exhibiting a range of proteolytic activities could be identified by these procedures. Purity of the enzyme fractions obtained from the DEAE-cellulose columns was tested by running polyacrylamide gels.
Maintaining cultures of ectomycorrhizal and plant pathogenic fungi in sterile water cold storage
Authors: Marx Donald H. , Daniel William J.
Published: April 2010

Mycelial cultures of 64 isolates of 14 species of ectomycorrhizal fungi and 27 isolates of 15 species of plant pathogenic fungi were grown on agar medium in Petri dishes. Mycelial discs, 8 mm in diameter, were removed from the cultures and stored in sterile distilled water in test tubes at 5 °C. Sixty-four, 61, and 41 isolates of the symbiotic fungi were viable after 1, 2, and 3 years storage respectively. Only 19, 10, and 8 isolates of the pathogenic fungi were viable after 1, 2, and 3 years storage, respectively. Time in pure culture before water storage did not affect viability of any fungal species following water storage. After 3 years storage, four fungi (three symbionts and one pathogen) were tested and found to have retained their original growth rates and root-infecting abilities on pine seedlings. The same four isolates, however, maintained on agar slants at 5 °C and subcultured every 4 to 6 months, grew slower and did not infect as many feeder roots of pine as the water-stored isolates.
Methane fermentation of rubber (Hevea brasiliensis) latex effluent
Authors: Rajagopalan K.
Published: April 2010

Four species of bacteria capable of CH4 fermentation of rubber latex effluent were isolated and identified as a Methanococcus, a strain of M. vannielii, a Methanobacterium and a strain of M. omelianskii. Auxanographic tests using the four strains showed growth and CH4 formation on a basal medium containing mineral salts or added H2 and Co2. Varied response was obtained when the basal medium was added to formate, acetate, butyrate, methanol, ethanol, and glucose. Previous work has established acid fermentation of Hevea latex arising from bacterial contamination and decomposition of the non-rubber constituents which consist of N-compounds, 2% quebrachitol, and smaller concentration of carbohydrates. This suggests that reduction of CO2 and fermentation of acids formed during metabolism in Hevea latex are possible pathways of CH4 production.
Studies on cardiolipin biosynthesis in Mycobacterium smegmatis
Authors: Mathur A. K. , Murthy P. Suryanarayana , Saharia G. S. , Venkitasubramanian T. A.
Published: April 2010

Supplementation of a growth medium with 5% glucose has been found to stimulate the formation of cardiolipin and phosphatidylethanolamine five- and threefold, respectively, in Mycobacterium smegmatis. The presence of both cytidine diphosphate diglyceride and phos-phatidylglycerol pathways of biosynthesis of cardiolipin in cell-free extracts has been demonstrated. The enzymes were localized in the fractions which contained membranes. Isonicotinic acid hydrazide and streptomycin sulfate inhibited the formation of cardiolipin.
Effects of phenylthiourea on growth and sclerotial formation of Sclerotium rolfsii and Whetzelinia sclerotiorum
Authors: Tourneau Duane Le
Published: April 2010

The growth rate of Sclerotium rolfsii and Whetzelinia sclerotiorum was reduced when 5 × 10−4 to 2 × 10−3 M l-phenyl-2-thiourea (PTU) was incorporated into synthetic media and potato dextrose agar (PDA). Whetzelinia sclerotiorum produced heavy aerial mycelia and few, if any, sclerotia in synthetic glucose-nitrate liquid medium containing 10−3 and 2 × 10−3 M PTU. At the same PTU concentrations in PDA, W. sclerotiorum formed abnormal sclerotia covered with a yellowish green exudate. Sclerotium rolfsii produced unusual patterns of aerial mycelia and no sclerotia on media containing 2 × 10−3 M PTU. With 5 × 10−4 and 10−3 M PTU, S. rolfsii produced sclerotial initials and some of these developed into atypical clumps of sclerotia. A yellow pigment developed when S. rolfsii grew on media containing PTU.
Biodegradation of petroleum by Chesapeake Bay sediment bacteria
Authors: Walker J. D. , Colwell R. R. , Petrakis L.
Published: April 2010

Chesapeake Bay sediment bacteria from oil-contaminated and oil-free environments were compared for their ability to utilize a South Louisiana crude oil. Preferential solubility, column chromatography, gas–liquid chromatography, and computerized mass spectrometry were used to provide new and useful information regarding biodegradation of fractions and components of the crude oil. Vibrio, Pseudomonas, and Acinetobacter spp. were isolated from the culture inoculated with oil-contaminated sediment, whereas coryneforms and Pseudomonas spp. were isolated from the culture inoculated with oil-free sediment. Microorganisms from the oil-free sediment produced greater quantities of polar n-pentane-insoluble components (asphaltenes) after degradation, whereas microorganisms from the oil-contaminated sediments provided greater degradation of saturated and aromatic hydrocarbons.
Soybean flower-to-seed movement of epiphytic bacteria
Authors: Leben Curt
Published: April 2010

Epiphytic tracer bacteria (a Pseudomonas sp. and an Arthrobacter sp.) from soybean buds were introduced into open flowers of greenhouse-grown soybean plants. Of the 177 resulting pods cultured after surface disinfection, tracers were recovered from within 24. Seed from two of these pods also carried tracers.
Studies on mode of action of a bacteriocin from Clostridium septicum
Authors: Schallehn Gisela , Krämer J.
Published: April 2010

A bacteriocin was found in the supernatant fluid of Clostridium septicum strain Ovinus. Sensitivity to the bacteriocin was confined to other strains of C. septicum and to strains of C. chauvoei; the other Gram-positive and Gram-negative bacteria tested for sensitivity were unaffected by the bacteriocin. The bacteriocin killed sensitive cells rapidly but cell lysis did not appear to be involved. The bacteriocin inhibited protein and RNA synthesis immediately after its addition to sensitive cells; DNA synthesis was inhibited 10 min later.
Spinin: the subunit protein of bacterial spinae
Authors: Easterbrook K. B. , Coombs R. W.
Published: April 2010

Bacterial spines (spinae) dissociate in hot sodium dodecyl sulphate to give a single novel subunit protein, spinin (mol. wt. 37 000 daltons). Spinae and spinin are introduced as new names.
Effect of various cultural conditions on the fatty acid and lipid composition of Choanephora cucurbitarum
Authors: Deven J. M. , Manocha M. S.
Published: April 2010

The fatty acid composition of the total and polar lipid fractions of Choanephora cucurbitarum grown under different cultural conditions were analyzed by thin-layer and gas–liquid chromatography. It was observed that temperature, age, pH, and light influenced the degree of unsaturation, this being due mainly to changes in the γ-linolenic acid concentration. The conditions used in this study did not alter the qualitative profile of fatty acids normally present in the organism. Neither did these conditions stimulate the production of further long-chain fatty acids (C20–C26) beyond γ-linolenic acid (C18:3) as reported earlier using growth media containing glutamic acid. The fatty acid pattern of lipid fractions though the same qualitatively, differed quantitatively. The polar lipid fractions, phosphatidyl choline, phosphatidyl ethanolamine, and diphosphatidyl glycerol showed an appreciable variation in γ-linolenic acid content under different cultural conditions. The degree of unsaturation of the various lipid fractions decreased with increases in temperature, light intensity, and pH, but within each treatment the same pattern of decreasing degree of unsaturation with increasing age was observed. The significance of these observations is discussed.
Studies on the cellular and free lipopolysaccharides from Branhamella catarrhalis
Authors: Johnson K. G. , McDonald I. J. , Perry M. B.
Published: April 2010

Cellular and free lipopolysaccharides obtained from Neisseria catarrhalis and Branhamella catarrhalis were found to be essentially identical. Both cellular and free lipopolysaccharides contained core-oligosaccharides of the following composition: D-glucose (4 mol), D-galactose (1 mol), 2-amino-2-deoxy-D-glucose (1 mol), and 3-deoxy-D-manno-octulosonic acid. Aldoheptose and phosphate components were below levels of detection. Several physical methods indicated that all core-oligosaccharide preparations were identical. Lipid A preparations from cellular and free lipopolysaccharides of both organisms were qualitatively and quantitatively similar; they were composed of decanoic acid, dodecanoic acid, 3-hydroxy dodecanoic acid, 2-amino-2-deoxy-D-glucose, phosphate, and ethanolamine. The results tend to justify the transfer of Neisseria catarrhalis to the genus Branhamella.
Effect of calcium and anaerobiosis on the thermostability of Bacillus stearothermophilus
Authors: Mosley Gregg A. , Card George L. , Koostra Walter L.
Published: April 2010

Bacillus stearothermophilus NCA 2184 lost viability and subsequently released cytoplasmic components when suspended in 0.1 M tris(hydroxymethyl)aminomethane (Tris) buffer (pH 7.2) and incubated at 60 °C. Cell lysis was prevented by the addition of 10 mM CaCl2 to the Tris-buffer suspension. Cells which were incubated under anaerobic conditions for 20 min in the growth medium before they were collected were stable in the Tris-buffer suspension without added calcium. Anaerobic incubation effected an increase in membrane cardiolipin which appeared to be related to the increase in the thermostability of the cells.
Somatic nuclear division in the sporidia of Ustilago violacea. III. Ultrastructural observations
Authors: Poon N. H. , Day A. W.
Published: April 2010

The paper provides detailed ultrastructural observations on nuclear division in the smut fungus Ustilago violacea and is based on previous light-microscopic work outlining the division in living and stained cells. The division as in many other Basidiomycetes is not intranuclear, but occurs within a partially disrupted membrane. The division takes place after migration of most of the nucleus into the bud cell, after limited breakdown of the nuclear membrane, and after the formation of a spindle between two spindle-pole bodies (SPB). The remaining part of the nucleus containing the nucleolus is left behind in the parent cell and degenerates there. The SPB, as in other Basidiomycetes, is a dome-shaped relatively structureless body, quite distinct from the flat plaques of many Ascomycetes and the elaborate centrioles of Phycomycetes. The SPB divides shortly before migration into the daughter cell and invariably is located at the apex of the migrating nucleus. Nuclear division is completed when the two masses of chromatin clustered about each of the SPB's are separated as the spindle elongates. One daughter nucleus reforms in the bud and the other is reformed in the mother cell.Cells fixed and stained by conventional light-microscopic methods were examined in the light of the electron-microscopic observations to determine whether these procedures induce artefacts. Aceto-orcein and Giemsa when used cold were found to produce relatively artefact-free preparations. However, previous results in which the cells were warmed gently in these stains are now seen to contain artefacts in the form of contracted chromatinic granules often arranged in chains. These artefacts may provide useful information but clearly they must be interpreted cautiously until the nature of the changes induced by heating are known.
Nitrogen fixation associated with grasses in Oregon
Authors: Nelson Arthur D. , Barber Lynn E. , Tjepkema John , Russell Sterling A. , Powelson Robert , Evans Harold J. , Seidler Ramon J.
Published: April 2010

Nitrogen fixation associated with both natural grasslands and grain crops of Oregon was studied using the acetylene-reduction assay. A number of the grasses collected had some acetylene-reducing activity. Agrostis tenuis Sibth. had substantially greater activity than any of the other species, with a mean rate estimated at 37 g N2 fixed per hectare per day. Assuming 100 days of activity, about 3 kg of N2 would be fixed per hectare per year. This quantity of nitrogen may be important in the maintenance of this species under natural conditions. Nitrogen-fixing microorganisms were isolated from the root surfaces of some of the grasses. Cultures of Bacillus macerans, Bacillus polymyxa, and Enterobacter cloacae were isolated from wheat roots as were two cultures which have not been assigned a specific taxonomic classification. Strains of N2-fixing Bacillus species and Gram-negative aerobic bacteria were isolated from Festuca and Agrostis.
Heterokaryosis and parasexuality in Pyricularia oryzae Cavara
Authors: Genovesi A. D. , Magill Cunt W.
Published: April 2010

Auxotrophs in three different races of Pyricularia oryzae were obtained following ultraviolet mutagenesis, and tested for complementarity on minimal medium. Prototrophic growth resulted between combinations of different auxotrophs of single strains, but not between strains. The growth did not result from crossfeeding, but required at least transitory heterokaryosis. Putative diploids, i.e., large prototrophic conidia, were readily isolated from the heterokaryons. In addition, conidia with nearly every possible combination of parental markers were found, showing that P. oryzae does indeed complete the parasexual cycle. The degree of genetic recombination found here may help to explain the extreme variability of this organism.
Immediate postnatal decontamination as a means of obtaining axenic animals and human infants
Authors: Ducluzeau R. , Raibaud P. , Lauvergeon B. , Gouet Ph. , Riou Y. , Griscelli C. , Ghnassia J.-C.
Published: April 2010

A technique not involving surgery is described for obtaining axenic (germ-free) newborn animals and human infants by decontamination immediately after birth. Three steps are involved: cleansing the perineal region of the mother with an iodinated bactericidal solution, washing the newborn with the same solution, and after the newborn has been placed in a sterile isolator, administering a single oral dose of an antibiotic mixture previously determined to be active against the fecal and vaginal flora of the mother. All of the newborn obtained by means of this technique, including 13 piglets, 2 lambs, and 4 human infants, were found to be axenic throughout their stay in the isolators. Four piglets obtained by the same technique, but without administration of antibiotic mixture, were found not to be axenic.This technique, as compared with methods of surgical delivery of axenic young, embodies a number of advantages. It is harmless to the mother and to the newborn, it is relatively inexpensive, and it obviates the risk of prematurity involved in elective surgical delivery before term.
Response of Bacillus thuringiensis to bacteriophage CP-51
Authors: Tassell Roger L. Van , Yousten Allan A.
Published: April 2010

Bacteriophage CP-51, a transducing phage of Bacillus cereus was able to replicate on all eight varieties of Bacillus thuringiensis tested. Three general plaque types were observed on each strain although one type predominated on each strain. The plaque size was uniform for each strain regardless of plaque type. The bacterial strain used as source of the phage had no effect on plaque type or size found on any host strain. CP-51 was stable in infected spores of B. thuringiensis var. kurstaki for at least 305 days even though most of the spores had lost refractility. Free phage particles produced in B. thuringiensis were stable for at least 10 days in broth at 14 °C but were very unstable at 4 °C.
Halobacterium saccharovorum sp. nov., a carbohydrate-metabolizing, extremely halophilic bacterium
Authors: Tomlinson Geraldine A. , Hochstein Lawrence I.
Published: April 2010

The previously described extremely halophilic bacterium, strain M6, metabolizes a variety of carbohydrates with the production of acid. In addition, the organism produces nitrite (but no gas) from nitrate, is motile, and grows most rapidly at about 50 °C. These characteristics distinguish it from all previously described halophilic bacteria in the genus Halobacterium. It is suggested that it be designated as a new species, Halobacterium saccharovorum.
Activities of α-ketoisovalerate, pyruvate, and α-ketoglutarate dehydrogenases in a mutant of Bacillus subtilis
Authors: Tu C. L. , Kaneda Toshi
Published: April 2010

An acetate-requiring leaky mutant was induced from Bacillus subtilis 168, and activities of its three α-keto acid dehydrogenases were compared with the respective activities of the parent strain. Both pyruvate and α-ketoisovalerate dehydrogenase activities in the mutant were considerably lower, being only 10–17% of those of the parent, but α-ketoglutarate dehydrogenase activity was unchanged. These dehydrogenases are complexes composed of three enzymes: a carboxylase, a lipoic reductase–transacylase, and a dihydrolipoyl dehydrogenase. The carboxylase activity of the affected complexes was no different. Total dihydrolipoyl dehydrogenase activity was only one-third. Thus dihydrolipoyl dehydrogenase is the defective enzyme in the two dehydrogenase complexes; the activity remaining in the mutant is accounted for by the activity of the intact α-ketoglutarate dehydrogenase.
Temperate phages of Clostridium perfringens type C
Authors: Grant R. B. , Riemann H. P.
Published: April 2010

Four phages isolated from carrier strains of Clostridium perfringens type C belong to two classes. The three phages of class I, c1, c3, and c4, are homoimmune and serologically closely related. The phage of class II, c5, is heteroimmune to the class I phages and not related to them serologically. Transduction experiments with several of the phages were negative. Mutants of the indicator strain with surface alterations occurred spontaneously in stock cultures. Electron micrographs show the phages of each class to be distinct yet similar, having polyhedral heads of about the same diameter 55 nm, and long, flexible tails without sheaths or collars. Phages c4 and c5 were characterized for their lysogenic properties. Phage c4 was inducible with mitomycin C. Both c4 and c5 were temperate viruses by the test of stability of their respective lysogens to phage-specific antisera.
The growth of nitrogen-fixing Azotobacter chroococcum in continuous culture under intense aeration
Authors: Hine P. W. , Lees H.
Published: April 2010

Azotobacter chroococcum (ATCC 7493) was grown in continuous culture with intense vortex aeration (stirring rate 1750 rpm) with up to 50% O2 in the gas phase. Under these conditions the dissolved O2 generally remained at zero while the cell growth rose to about twice the normally accepted value. The meaning of the term "O2-limitation" in N2-fixing A. chroococcum cultures is critically examined.
Study on the efficiency of four procedures for enumerating coliforms in water
Authors: Dutka B. J. , Tobin S. E.
Published: April 2010

Four coliform estimation procedures were compared as to their ability to enumerate coliform bacteria (oxidase-negative lactose fermenters) from sewage, effluent, and various fresh waters in the lower Great Lakes Region of Canada. Two of the procedures used and which are cited in the American Public Health Association (APHA) Standard Methods were a most probable number (MPN) technique using lauryl tryptose broth (LST) and brilliant green bile 2% broth (BGB), and a membrane filtration (MF) technique using m Endo agar LES. The other two procedures were an MPN technique using Parhad chemically defined synthetic medium (PCDS) and BGB developed for Indian fresh waters and an MF (mC agar) technique developed for seawater.Data indicate that within the survey area, maximum population estimates were achieved by the MF procedure using m Endo agar LES and that each procedure was selective for different genera of the Enterobacteriaceae. Discussions concerning standard versus reference procedures are presented.
Le Palmier dattier et la fusariose. II. Rapport entre la stéréochimie des oses et quelques-uns de leurs dérivés et la croissance du Fusarium oxysporum f. sp. albedinis (Killian et Maire) Gordon
Authors: Bounaga Nicole
Published: April 2010

Fusarium oxysporum albedinis was grown in the presence of 20 different sugars or their derivatives. The results obtained were correlated with the stereochemical structure of the main oses. Osmotic phenomena as well as active and selective transport were used to explain differences in utilization of oses of very near structure. Based on the affinity of the fungus for mannose, a hypothesis is formulated concerning the fungus action in the host. [Journal translation]
Phleomycin-stimulated solubilization of deoxyribonucleic acid in Escherichia coli. II. Inhibition of solubilization by bacteriophage T4
Authors: Farrell Larry D. , Reiter Harvard
Published: April 2010

Phleomycin-stimulated solubilization of Escherichia coli DNA is inhibited by infecting the cells with mutants of bacteriophage T4 before treatment with the antibiotic, inhibition requiring phage-specified protein synthesis. Two different modes of inhibition can be differentiated by infecting with mutants which are defective in an early state (gene den A−; endonuclease II-independent inhibition) or a late stage (gene 46−; endonuclease II-dependent inhibition) of phage-directed degradation of host DNA. Endonuclease II-independent inhibition results from interference with phleomycin-induced release of host DNA from the cytoplasmic membrane. In the presence of endonuclease II, the host DNA is converted to fragments, with average molecular weights of 106 daltons, the further degradation of which is not promoted by continuous exposure of the cells to phleomycin.
Selective enrichment of Shigella in the presence of Escherichia coli by use of 4-chloro-2-cyclopentylphenyl β-D-galactopyranoside
Authors: Park C. E. , Rayman M. K. , Szabo R. , Stankiewicz Z. K.
Published: April 2010

A procedure involving the use of citrate-buffered lactose broth (pH 6.5) containing an analogue of a β-galactoside (4-chloro-2-cyclopentylphenyl β-D-galactopyranoside) has been developed for the enrichment of Shigella in competition with a 100-fold higher population of Escherichia coli. The system makes use of the β-galactosidase activity of E. coli which hydrolyzes the phenolic derivative of β-galactoside to galactose and an aglycone moiety (4-chloro-2-cyclopentylphenol) which is toxic to E. coli but is tolerated by Shigella. The procedure is particularly effective in the enrichment of S. sonnei and S. flexneri; S. dysenteriae and S. boydii are enriched to a lesser extent.
Effect of chemicals used as nitrification inhibitors on the denitrification process
Authors: Henninger Nancy M. , Bollag Jean-Marc
Published: April 2010

Several chemicals used as nitrification inhibitors were tested to determine their effect on denitrification by a Pseudomonas sp. and in soil. Denitrification by the bacterium was suppressed by 2-chloro-6-(trichloromethyl)-pyridine (N-Serve) at a concentration of 50 ppm, while 2,5-dichloroaniline caused the accumulation of nitrite in the culture medium. The nitrification inhibitors had little effect on the denitrifying activity in soil under anaerobic conditions. 2-Sulfanilamidothiazole inhibited denitrification to some extent and samples supplied with potassium azide produced N2O rather than N2 as the predominant gas.
Urease-negative strains of Clostridium sordellii
Authors: Nakamura S. , Shimamura T. , Nishida S.
Published: April 2010

Twenty-seven of 37 non-toxigenic, urease-negative strains originally identified as Clostridium bifermentans that were isolated in the Antarctic were reidentified as C. sordellii by the tests for DNA–DNA homology, by the absence of mannose in the cell wall, and by growth inhibition of mannose. The test for cell wall sugar components of urease-negative and -positive strains of C. sordellii revealed that glucose, mannose, and rhamnose could not be detected in any of eight urease-negative strains used but galactose was detectable in seven of the eight strains and that glucose or galactose or both of the two sugars were present in the urease-positive strains tested.
Enumeration of sublethally heated staphylococci in some dried foods
Authors: Hurst Andre , Hendry G. S. , Hughes Ashton , Paley Beverly
Published: April 2010

The effect of 45 substances to restore the salt tolerance of sublethally heat-injured Staphylococcus aureus was tested. Sodium pyruvate, yeast extract, L-histidine, casitone (Difco), adenosine triphosphate, and acetyl phosphate were effective. For enumeration a repair medium was first used, containing sodium pyruvate and penicillin in 1% skim milk. This step was followed by counting on Baird-Parker agar with penicillinase. This method was selective; fewer than 100 staphylococci/g food could be enumerated and it gave counts about 8 times higher than the method of Giolitti and Cantoni used as a five-tube most probable number technique. Heat injury sensitized S. aureus to polymyxin.
Adsorption, desorption, and activity of glucose oxidase on selected clay species
Authors: Morgan H. W. , Corke C. T.
Published: April 2010

The adsorption of the enzyme glucose oxidase (EC 1.1.3.4) to clays followed the pattern described for other proteins as being pH dependent. Maximum adsorption occurred at or below the isoelectric point of the enzyme. The amount of enzyme adsorbed to clay was influenced by the type of clay used, and also the saturating cations. Initially adsorbed enzyme showed low specific activities, and as amounts of enzyme adsorbed approached maximum saturation of clay, specific activities increased approaching that determined for free enzyme.The adsorption of glucose oxidase involved a temperature-independent cation-exchange mechanism, and enzyme adsorbed to surfaces of clay could be desorbed in active form by elevation of pH of suspending solution. This was followed by a slower temperature-dependent fixation, probably by hydrogen bonding, which resulted in protein being irreversibly adsorbed to clay surfaces.It is proposed that on adsorption of glucose oxidase to clay surfaces unravelling of the protein structure occurred, which allowed penetration of protein into the interlamellar spaces of montmorillonite. This proposal was based on the observed expansion of montmorillonite to 23 Å, and the decreases in amount of a second-protein lysozyme adsorbed with extended incubation times of glucose oxidase – clay complexes at pH 4.5.
Preparation and chemical properties of the outer membrane of a moderately halophilic gram-negative bacterium
Authors: Hiramatsu T. , Yokoyama T. , Ohno Y. , Yano I. , Masui M. , Iwamoto T.
Published: April 2010

Outer membranes, almost free from peptidoglycan components, were prepared from a moderately halophilic gram-negative bacterium grown in a medium containing 2 M NaCl. The outer membrane was easily released, leaving mureinoplasts, by mild desalting in a 20% sucrose solution containing 50 mM tris(hydroxymethyl)aminomethane-HCl buffer, pH 7.8. The membrane was recovered by treatment with DNase I and CsCl buoyant density centrifugation.Chemical analyses revealed that the outer membrane was mainly composed of 31% protein, about 20% extractable lipids (mainly phospholipids), and lipopolysaccharides. The proteins had about 18 mol% excess of acidic over basic amino acids. The phospholipids comprised phosphatidyl ethanolamine, phosphatidyl glycerol, cardiolipin, and an unidentified phospholipid containing glucose, which seemed mainly associated with the outer membrane. The content of lipopolysaccharides in the outer membrane was calculated arbitrarily as 30% from the heptose content. A unique feature of these lipopolysaccharides seemed to be a higher lipid content than found in lipopolysaccharides of other gram-negative bacteria. The major fatty acids of bound lipids of the outer membrane resembled those of the lipopolysaccharides obtained from cell envelope preparation and contained high concentrations of 3-hydroxy lauric acid.
Role of lipopolysaccharide in adsorption of coliphage T4D to Escherichia coli B
Authors: Watanabe Takashi
Published: April 2010

Coliphage T4D was strongly adsorbed to intact lipopolysaccharides and alkaline and lipase-treated lipopolysaccharides from cells of Escherichia coli B, but was not so adsorbed to heat-treated cells. In contrast, coliphage T2h was not adsorbed to lipopolysaccharides and the heat-treated cells.Acid hydrolysate of lipopolysaccharides strongly inhibited the adsorption of phage T4D to acetone and ether-treated cells. The adsorption of phage T4D to the acetone and ether-treated cells was markedly inhibited by authentic D-glucosamine, N-acetyl-D-glucosamine, α-methyl-N-acetyl-D-glucosaminide, α-methyl-D-glucoside, and D-maltose. Authentic D-glucose and D,L-2,6-diaminopimelic acid also showed similar activity. These compounds did not affect the adsorption of phage T2h to the acetone- and ether-treated cells. Concanavalin A and wheat-germ agglutinin inhibited phage T4D adsorption to the acetone and ether-treated cells probably by blocking the phage-receptor sites on the cell wall. The blocking by concanavalin A and by wheat-germ agglutinin was reversed by α-methyl-D-glucoside and by α-methyl-N-acetyl-D-glucosaminide, respectively. Results suggested the possibility that coliphage T4D requires N-acetyl-D-glucosaminyl-glucose or glucosyl-D-glucosamine residues of the core of lipopolysaccharides for the initial attachment to the cell wall of Escherichia coli B.
Some properties of an unidentified halophile: growth characteristics, internal salt concentration, and morphology
Authors: Matheson Alastair T. , Sprott G. Dennis , McDonald I. J. , Tessier Horace
Published: April 2010

An unidentified halophile isolated from plates of a complex agar medium containing 4.25 M NaCl showed optimum growth in broths containing 0.5–1.0 M NaCl but exhibited a wide range of growth from 0.045–4.5 M. The organism can be classified as a facultative halophile with wide salt tolerance. Logarithmic phase cells grown in media containing 0.5 M NaCl were rod-shaped in long chains which changed to smaller, single, or paired cells in stationary growth. The internal Na+ and K+ concentrations were 0.05 M and 0.34 M for logarithmic phase cells and 0.29 and 0.32 M for stationary phase cells. In 4.3 M NaCl media the cells were rod-shaped throughout the growth cycle, occurring primarily in pairs. The internal Na+ and K+ concentrations in cells in logarithmic phase growth were 0.62 M and 0.58 M while in stationary phase growth these values were 1.01 M and 0.66 M respectively. In contrast, logarithmic phase cells of the extreme halophile Halobacterium cutirubrum had internal Na+ and K+ concentrations of 0.80 M and 5.32 M when grown in 3.3 M NaCl. The internal Na+ and K+ concentrations, therefore, in the unidentified halophile do not resemble those found in H. cutirubrum but are much closer to those present in Escherichia coli.
Pseudomonas aeruginosa lipopolysaccharide: factors influencing toxicity for isolated mitochondria and endotoxin properties
Authors: Greer G. Gordon , Milazzo F. H.
Published: April 2010

In the present study Pseudomonas aeruginosa lipopolysaccharide (LPS) exhibited the following endotoxin properties: (1) toxicity for mice; (2) gelation of the Limulus lysate; (3) induction of a localized Shwartzman reaction in the skin of rabbits, and (4) anticomplementary activity.Differences in LPS toxicity as measured with the rat liver mitochondrial assay system were found to be related to the nature of the bacterial growth media, the functional integrity of mitochondria, and the time and temperature of mitochondrial assay. The significance of these findings to P. aeruginosa infections is discussed, and it is concluded that LPS is a factor of importance.
Mannitol production in fungi during glucose catabolism
Authors: Boonsaeng Vichai , Sullivan Patrick A. , Shepherd Maxwell G.
Published: April 2010

The levels of phosphofructokinase (EC 2.7.1.11) and mannitol-1-phosphate dehydrogenase (EC 1.1.1.17) have been determined in a number of Mucor and Penicillium species. Mannitol-1-phosphate dehydrogenase was found in only one species of mucor, Mucor rouxii, and this with a specific activity much lower than that found in Penicillium species. All of the fungi tested in the Ascomycetes class exhibited mannitol-1-phosphate dehydrogenase activity. Interference from both mannitol-1-phosphate dehydrogenase and NADH oxidase (EC 1.6.99.5) caused some difficulty initially in detecting phosphofructokinase in Penicillium species; the Penicillium phosphofructokinase is very unstable. Penicillium notatum accumulates mannitol intracellularly; detection of mannitol-1-phosphate dehydrogenase and mannitol-1-phosphatase (EC 3.1.3.22) activity in cell-free extracts indicates that the mannitol is formed from glucose via fructose-6-phosphate and mannitol-1-phosphate; no direct reduction of fructose to mannitol could be detected. The mannitol-1-phosphate dehydrogenase was specific for mannitol-1-phosphate and fructose-6-phosphate; NADP+(H) could not replace NAD+(H). The phosphatase (EC 3.1.3.22) exhibited a distinct preference for mannitol-1-phosphate as substrate; all other substrates tested exhibited less than 25% of the activity observed with mannitol-1-phosphate.
β-Galactosidase from Bacillus stearothermophilus
Authors: Goodman Richard E. , Pederson Dennis M.
Published: April 2010

Several strains of thermophilic aerobic spore-forming bacilli synthesize β-galactosidase (EC 3.2.1.23) constitutively. The constitutivity is apparently not the result of a temperature-sensitive repressor. The β-galactosidase from one strain, investigated in cell-free extracts, has a pH optimum between 6.0 and 6.4 and a very sharp pH dependence on the acid side of its optimum. The optimum temperature for this enzyme is 65 °C and the Arrhenius activation energy is about 24 kcal/mol below 47 °C and 16 kcal/mol above that temperature. At 55 °C the Km is 0.11 M for lactose and 9.8 × 10−3 M for o-nitrophenyl-β-D-galactopyranoside. The enzyme is strongly product-inhibited by galactose (Ki = 2.5 × 10−3 M). It is relatively stable at 50 °C, losing only half of its activity after 20 days at this temperature. At 60 °C more than 60% of the activity is lost in 10 min. However, the enzyme is protected somewhat against thermal inactivation by protein, and in the presence of 4 mg/ml of bovine serum albumin the enzyme is only 18% inactivated in 10 min at 60 °C. Its molecular weight, estimated by disc gel electrophoresis, is 215 000.
The effect of ribonuclease on the penetration of R17 phage A-protein and RNA
Authors: Wong Kenneth , Paranchych William
Published: April 2010

In an attempt to throw further light on the relationship of R17 phage RNA and A-protein during the early stages of infection, studies were carried out to determine the effect of ribonuclease (ribonuclease 1, EC 3.1.4.22) on the ability of these two phage components to penetrate into host bacteria. It was found that the penetration of phage RNA is affected by ribonuclease concentrations as low as 0.1 μg/ml, while the penetration of phage A-protein was unaffected by ribonuclease concentrations as high as 20 μg/ml. In addition, it was found that a significant fraction of the phage RNA is resistant to the ribonuclease effect. This RNase-resistant portion of the phage population increased with increasing phage concentrations, and gave rise to the penetration of intact, 28S RNA molecules that produced the expected number of infectious centers. These findings are discussed in terms of a model for phage RNA injection in which the A-protein functions both as an attachment organelle and a pilot protein that guides the RNA from the capsid to the exterior surface of the F pilus, and thence into the host bacterium.
Characterization of Streptococcus bovis bacteriophages
Authors: Iverson W. G. , Millis Nancy F.
Published: April 2010

About 25 Streptococcus bovis bacteriophages were isolated from abattoir wastes, bovine rumen fluid, and lysogenic strains of S. bovis. Eight phages were selected and characterized by morphology, stability, rate of adsorption, single-step growth curve, serum neutralization, and antigenic relationship. Two distinct morphological phage types were found, one of which has not been previously reported for group D streptococci.
The fine structure of conidial development in the genus Torula. III. T. graminis Desm.
Authors: Ellis D. H. , Griffiths D. A.
Published: April 2010

Torula graminis produced blastoconidia in acropetalous chains after the evagination of a characteristic conidiogenous cell. Conidia consisted of up to 15 cells and their cell wall was differentiated into an outer melanized zone and an inner hyaline zone. A consistent cytoplasmic feature of conidial cells was the presence of dictyosomal-like membranous stacks often closely associated with the nucleus. Vesicles that developed from the dictyosomal-like cisternae were probably involved in conidial wall synthesis.
Effet antibactérien de quelques mycotoxines et métabolites fongiques vis à vis de souches de Bacillus thuringiensis (Berliner) sensibles ou résistantes à l'aflatoxine B1
Authors: Boutibonnes P.
Published: April 2010

Antimicrobial activity of pure preparations of mycotoxins and fungal metabolites was studied against strains of Bacillus thuringiensis (Berliner). Two resistant strains, called stable-variant, were isolated after treatment with high concentrations of aflatoxin B1. These strains were then resistant also towards compounds with a double furan system (aflatoxins B1, B2, G1, G2, and sterigmatocystin).
Electron microscopy of antibody-labelled cells of Streptococcus mutans
Authors: Emyanitoff R. G. , Rucinsky T. E. , Birdsell D. C.
Published: April 2010

Examination of immune complexes between cells of Streptococcus mutans and homologous antiserum by the techniques of thin-sectioning and freeze-etching revealed that the cells were embedded within an extensive matrix 80–90 nm thick with defined boundaries.
Isolation and characterization of phenotypes of mycobacteria
Authors: Turcotte Raymond , Quevillon Marc
Published: April 2010

Several strains of mycobacteria grown as surface pellicle on liquid Sauton's medium under semianaerobic conditions dissociated into three phenotypes: phenotypes 1, 2, and 3. Only phenotype 1 could be obtained in a pure state. None of these phenotypes was found to be stable: they convert from one into another and all revert to the parental strain when replaced in their usual aerobic cultural conditions. Comparative studies of phenotypes 1 and 3 have shown that significant differences exist in their physiological behaviour and antigenic composition.
Dégradation chimique et enzymatique des parois de Helminthosporium spiciferum. Rôle protecteur des pigments
Authors: Berthe M. C. , Bonaly R. , Reisinger O.
Published: April 2010

Cell walls of the fungus Helminthosporium spiciferum, prepared by mechanical grinding of the cells, were treated chemically and with helicase. The purified cell walls and the fractions were analyzed chemically and micromorphologically to localize the major cell-wall constituents and to determine the protective role of the pigments against degradative processes. The encrusting of the external area by the pigments associated with chitin formation leads to an increased resistance of this cell-wall area against the degradative processes.
Reduction of acetylene by stationary cultures of free-living Rhizobium sp. under atmospheric oxygen levels
Authors: Evans William R. , Keister Donald L.
Published: April 2010

The reduction of acetylene to ethylene by stationary (non-shaking) cultures of free-living rhizobia under atmospheric oxygen levels has been demonstrated. Under these conditions the development of the activity is inhibited by 10 mM NH4Cl and about 20% of oxygen is required for maximal activity. When the stationary cultures were shaken, oxygen concentrations of 1% and higher were found to be inhibitory. Specific activities of 20 and 40 nmol of acetylene reduced h−1 mg−1 protein were observed.
Stable L-forms of Clostridium perfringens and their growth on glass surfaces
Authors: Mahony D. E. , Moore T. I.
Published: April 2010

L-forms of Clostridium perfringens were induced in brain heart infusion broth containing 10% sucrose and 2 units of penicillin. After a few hours of growth, spheroplasts, granules, and elongated bacilli were apparent. At 24-h intervals, serial subcultures were made in the above medium which resulted in a culture composed entirely of spheroplasts (or protoplasts) and granules. Upon the withdrawal of penicillin these L-form cultures grew well and, after 100 passages, there was no reversion to the bacillary form. Sucrose could also be withdrawn from the medium. The effects of centrifugation, osmotic stabilizer, ultraviolet light, temperature, pH, and lyophilization upon stable L-forms were examined. L-forms were found to attach to the walls of culture tubes during growth and sheets of L-form growth were obtained on cover slips in Leighton tubes and on the sides of medicine bottles.
Conjugation in the yeast Guilliermondella selenospora Nadson et Krassilnikov
Authors: Ru N. J. W. Kreger-van , Veenhuis M.
Published: April 2010

Conjugation in Guilliermondella selenospora took place via conjugation tubes from cells in different hyphae. Afterwards, a septum was formed in the channel connecting the two cells which turned into asci or formed buds which became asci. Conjugation between adjacent hyphal cells was also found. Cell contact without fusion with denticles and stalks, which occurs in G. selenospora, was compared with conjugation.
ICMSF methods studies. VII. Indicator tests as substitutes for direct testing of dried foods and feeds for Salmonella
Authors: Silliker J. H. , Gabis D. A.
Published: April 2010

The correlation between the occurrence of indicator organisms and salmonellae in the same sample homogenate of various classes of dried foods was studied. In the first phase of the work involving 5837 samples, 1943 contained fecal coliforms and 100 contained Salmonella. Fecal coliforms were not detected in 53 of the Salmonella-positive samples. In the second phase, an additional 637 samples were tested for the presence of Enterobacteriaceae, coliforms, fecal coliforms, and Salmonella. Enterobacteriaceae were detected in 538 samples, coliforms in 506, fecal coliforms in 343, and Salmonella in 49. All Salmonella-positive samples were also positive for Enterobacteriaceae and coliforms. However, 6 of 49 Salmonella-positive samples were negative for fecal coliforms. Therefore, the use of the fecal coliform test as an index of Salmonella contamination would result in the rejection of Salmonella-negative foods and the acceptance of Salmonella-positive foods. It is concluded that none of these indicator groups are reliable as an index of Salmonella contamination in dried foods.
Some comparative observations on the relative contributions of alternate pathways in the metabolism of glucose by Candida utilis
Authors: Dawson P. S. S. , Okada W. , Steinhauer L. P.
Published: April 2010

Candida utilis was grown in batch, chemostat, and continuously synchronised (phased) culture on a nitrogen-limited glucose mineral salts medium: phosphorus- and carbon-limited phased cultures were also used. The 14CO2 evolved from [G-1-14C] and [G-6-14C] was used, as a simple C1/C6 ratio, to observe the relative changes in EMP and HMP contributions during growth of the cultures. The ratio varied during the cell cycle, and changed with growth rate, and with nutrient limitation. The changes generally indicated that the HMP predominated, most notably in the early part of the batch-growth sequence and early in the cell cycle.The overall results reflected the relative merits of the different cultivation techniques for examining microbial metabolism: the advantage of a greater resolution by the synchronised method, based upon the unit performance rather than the randomised mean performance of the cell population, was demonstrated.
The use of cellulose products to reduce agar concentration in microbiological media
Authors: Myrvik Alan L. , Whitaker Janice M. , Cannon Robert E.
Published: April 2010

The use of agar in media for culturing microorganisms is fundamental to microbiological investigations. Shortages of agar have caused increased costs and difficulty in obtaining media. Evidence is presented for the use of carboxymethylcellulose (CMC), an inert compound, in conjunction with agar to reduce the concentration of agar necessary to achieve a solid plating surface. A variety of bacteria, blue-green bacteria, fungi, and a yeast were tested for growth on CMC agar media. T-2 bacteriophage and three cyanophages were tested for plaque-forming efficiency on CMC agar plates. Selective and differential media were also formulated with a CMC agar supplement. Growth of all microorganisms was comparable on CMC and agar control. Use of cellulose products provides a means of decreasing agar consumption without affecting success ful cultivation of microorganisms.