bluuebunny/crossref_metadata_2025 huggingface dataset:
Le virus de la rubéole. I. Morphologie et protéines structurales
Authors: Payment Pierre , Ajdukovic Djordje , Pavilanis Vytautas
Published: April 2010

Degradation of purified rubella virus by heat treatment (37, 45, or 56 °C) revealed the following structures. The viral envelope, a modified cellular membrane, bears spherical subunits, 5–6 nm in diameter, hexamers, or pentamers. Two glycoproteins, VP-2 (50 000 daltons) and VP-3 (63 000 daltons), are associated with the envelope. The nucleocapsid is formed by the condensation of the viral ribonucleic acid on a central structure 10 nm in diameter. Only one protein, VP-1 (35 000 daltons) is present in the nucleocapsid. Similarity between rubella virus and Togaviruses is discussed.
Le virus de la rubéole. III. Purification des membranes de cellules Vero infectées ou non-infectées
Authors: Payment Pierre , Ajdukovic Djordje , Pavilanis Vytautas
Published: April 2010

Separation of Vero cell membrane in a discontinuous sucrose gradient reveals five fractions. After infection a sixth fraction appears. It contains virions but mostly modified membranes with subunits 5–6 nm in diameter, probably the hemagglutinin. None of the enzymes used was associated with this fraction. No modification of the other fractions was observed after infection.
A simple fluorescence staining technique for in situ soil microorganisms
Authors: Mayfield C. I.
Published: April 2010

A simple, rapid, staining technique using the magnesium salt of 1-anilino-8-naphthalene sulfonic acid is described. Treatment of soil with an aqueous, membrane-filtered solution (3.5 mg/ml) of the salt causes the soil microorganisms to fluoresce when examined with light from a mercury arc light source.
The effect of sodium chloride on the growth and morphology of dermatophytes and some other keratolytic fungi
Authors: Kane Julius , Fischer J. B.
Published: April 2010

A study of the influence of various concentrations of NaCl on 21 species of dermatophytes and other keratolytic fungi was made. Based on the sensitivity of the species to various concentrations of NaCl, it was possible to divide them into five groups. Microsporum ferrugineum and Trichophyton concentricum and T. tonsurans were the most sensitive to NaCl and were inhibited by 5%. The greatest number of species were inhibited by 12% NaCl. The fungi most tolerant to NaCl were M. cookei and M. nanum, and T. mentagrophytes, T. schoenleinii, and T. terrestre. These species were inhibited by 15%. NaCl prevented any variant change in Epidermophyton floccosum, T. mentagrophytes, and M. gypseum, but promoted a change in phenotype in M. audouinii and M. cookei, and T. gallinae. It is suggested that the word "pleomorphism" be replaced by the term sterile albinism. This term refers to that kind of cultural change when there is no evidence of sporulation and the white fluffy mycelium consists of fine sterile hyphae.Sterile albino strains of E. floccosum were induced to form macroconidia on Sabouraud cycloheximide chloramphenicol gentamicin agar (SCCGA) containing 3–5% NaCl. Also, M. audouinii formed microconidia and macroconidia in velvety growth cultured on SCCGA containing NaCl.
Absorption of tuberculin-active components with mycobacterial antibodies
Authors: Turcotte R.
Published: April 2010

Protoplasmic extracts isolated from four different species of mycobacteria were treated with their corresponding antibodies; this resulted in a loss of 80 to 95% of their tuberculin activity when used as skin-test materials in guinea pigs sensitized with the homologous strains. The biological activity was recovered from the immuneprecipitates and the soluble immune complexes after dissociation with sodium thiocyanate and fractionation of columns of Sephadex G-100. It is concluded that most of the sensitins in mycobacterial extracts behave as antigens.
The microbial colonization of some woods of small dimensions buried in soil
Authors: Sharp R. F.
Published: April 2010

Several species of wood veneer, including some in a green undried state, were buried in various soils, and at intervals the colonists were isolated and identified. In addition, veneers were deteriorated for different periods of time, sterilized, and then reburied in the same soil. Isolates were obtained before sterilization and compared with those found afterwards. In each case the colonization involved a small number of microfungi and, because similar species were repeatedly isolated, an absence of succession under laboratory conditions was indicated.Deteriorating cubes of wood were periodically assayed for their glucose content, pH of exudates, and the release of microbial cellulase and amylase. A lack of any consistent change in colonist activity, with respect to these factors, again indicated an absence of stages during decay.The colonization pattern was contrasted with successions described in previous studies and the simplest explanation was given for the differences found.
Isolation and identification of rumen bacteria capable of anaerobic phloroglucinol degradation
Authors: Tsai Chii-Guary , Jones G. A.
Published: April 2010

Eight strains of rumen bacteria capable of degrading phloroglucinol (1,3,5-trihydroxybenzene) under anaerobic conditions were isolated from enrichment cultures of the bovine rumen microflora established in a prereduced medium containing 0.02 M phloroglucinol. Five of the strains were facultatively anaerobic Gram-positive streptococci which were identified as Streptococcus bovis. Three strains of obligately anaerobic Gram-positive cocci were assigned to the genus Coprococcus. Anaerobic cultures of the Streptococcus bovis strains in a 40% rumen fluid medium initially containing 0.02 M phloroglucinol degraded 50–80% of the substrate within 2 days, whereas cultures of the Coprococcus strains degraded more than 80% of the substrate under the same conditions. The Streptococcus bovis strains were incapable of degrading phloroglucinol in brain heart infusion or in the medium of de Man, Rogosa, and Sharpe (MRS broth) incubated aerobically.
A new method of obtaining zygotes in Saccharomyces cerevisiae
Authors: Lee Eng-Hong , Lusena C. V. , Johnson Byron F.
Published: April 2010

Experiments leading to a simple method of mass zygote formation in Saccharomyces cerevisiae are described. This method ordinarily requires only about 3 h of incubation, and consistently yielded 55–65% zygotes in seven different crosses among six different strains. Matings involving one strain required about 4 h of incubation but otherwise the results were comparable.
Virus survival on inanimate surfaces
Authors: Mahl M. C. , Sadler C.
Published: April 2010

The persistence of several types of viruses on hard, inanimate surfaces under different relative humidities, temperatures, and types of surfaces was investigated. No differences in survival on glass, vinyl asbestos tile, ceramic tile, and stainless steel were found. Under conditions of low humidity and room temperature, adenovirus, poliovirus, and herpes simplex virus survived for at least 8 weeks. Vaccinia and coxsackie viruses survived for at least 2 weeks but differences due to humidity and temperature were not detected. The long-term survival of viruses on common surfaces found in many environments, in addition to the laboratory, emphasizes the possible role of hard surfaces in the transmission of viruses.
Aerobic adaptation in yeast. I. Changes in metabolic intermediates during a step-down anaerobic–aerobic transfer
Authors: Bruver Rita M. , Ball A. J. S. , Tustanoff E. Reno
Published: April 2010

Early investigation into the mechanism of mitochondriogenesis in the facultative anaerobe Saccharomyees cerevisiae used anaerobic–aerobic transitions as model systems to study the in vivo assembly of these oxidative organelles. This methodology has become entrenched in the early literature and as a result a definitive study has been undertaken utilizing this protocol (high hexose, complete medium under anaerobic growth transferred to low hexose, minimal medium with aerobic environment) to study the altered distribution of various metabolites during these transitions.Measurement of all the glycolytic, and some tricarboxylic acid intermediates during such a transition has elucidated the following points. On a qualitative basis, the metabolic controls prevalent in these growing cultures are similar to those identified in yeast under less physiological conditions. Also, the effect of anaerobic catabolism, which preconditions enzyme and pool levels in the yeast, is of paramount importance in determining the events subsequent to oxygen challenge.However, this experimental approach has severe limitations and does not lend itself to a clear-cut delineation of the events that occur during the process of mitochondriogenesis.
Aerobic adaptation in yeast. III. Changes in metabolic intermediates during anaerobic–aerobic transitions in exponentially growing cultures
Authors: Bruver Rita M. , Ball A. J. S. , Tustanoff E. Reno
Published: April 2010

The changes in mechanism of control and in the mode of metabolism which yeast cells undergo when an anaerobic–aerobic transition is imposed on them has received much attention. One experimental approach to this type of investigation has been a step-down transition. The data from our experiments (cf. papers I and II of this series) has shown that this model is too complex to arrive at meaningful interpretation. We therefore repeated these measurements of glycolytic and citric acid cycle metabolites in cells growing on either glucose or galactose media and exposed to exponential N2 → O2 transitions. This type of experiment is designed to examine directly the effect of oxygen challenge. Interpretation of this new data shows that the major metabolic control operating in the two hexose cultures are different and suggests that adenine nucleotide controls glucose cells whereas galactose cell metabolism is controlled by the NAD/NADH balance. This concept is discussed.
Pseudomonas aeruginosa lipopolysaccharide: an uncoupler of mitochondrial oxidative phosphorylation
Authors: Greer G. Gordon , Milazzo F. H.
Published: April 2010

The addition of Pseudomonas aeruginosa KCIIR LPS to respiring mitochondria stimulated the rate of substrate oxidation, reduced the respiratory control ratio, stimulated oxygen uptake in state 4, and released the inhibition imposed upon state 3 by atractyloside. It was concluded that LPS acted as an uncoupler of oxidative phosphorylation and that it produced effects similar to those observed with the classical uncoupler 2,4-dinitrophenol.
Impairment of reactivity to lepromin by mycobacterial antigens related to, or identical with, Mycobacterium leprae
Authors: Kwapinski J. B. G. , Bechelli L. M. , Haddad N. , Simao Emilia Tavares
Published: April 2010

Three hundred and twenty young children were injected with Bacillus Calmette–Guérin (BCG) saline, or with one of the mycobacterial cytoplasmic antigens related with Mycobacterium leprae. At an appropriate time thereafter they were tested for dermal hypersensitivity to the antigens and for reactions to lepromin.Whereas all the antigens induced cell-mediated immunity, the incidence and intensity of late response to lepromin were significantly reduced in children preinjected with the cytoplasmic mycobacterial antigens, as contrasted with increased lepromin reactivity in the BCG group and with the findings in saline-injected children.
Preparation of a dane core (hepatitis B) antigen from human plasma
Authors: Fauvel M. , Babiuk L. , Sheaff E. T. , Spence L.
Published: April 2010

Hepatitis B surface antigen (HBsAg) positive plasma, obtained from blood donors, was used to prepare an antigen (HBcAg) from the inner core of the Dane particle, the larger of the two spherical particles found in the blood in hepatitis B infection. The antigen was prepared by a series of centrifugation procedures on caesium chloride and sucrose gradients. Dane particle-rich fractions obtained from these gradients and concentrated by centrifugation were treated with Tween 80 to remove the outer coats from the particles. The remaining Dane particle cores were recovered by velocity sedimentation on a sucrose gradient. Preparations containing the Dane cores were used as antigens in the immune electron microscopy and complement fixation tests to demonstrate the specificity of HBcAg and lack of cross relationship with HBsAg. HBcAg will be used for the study of hepatitis B infections in man.
Streptomycin resistance in chloramphenicol-producing strains of Streptomyces species 3022a
Authors: Francis M. M. , Cella R. , Vining L. C.
Published: April 2010

Resistance to low (5 μg/ml) concentrations of streptomycin in agar media was not inherited by all of the surviving population. Outgrowth of cultures in liquid media supplemented with the antibiotic depended upon inoculum size. Antibiotic titers in the supplemented cultures decreased during incubation, and an inactive radioactive product was detected when [14C]streptomycin was used. This low-level resistance is, therefore, attributed to enzymic inactivation of the antibiotic. Growth in 10 μg/ml or higher concentrations of streptomycin on agar media was due to selection of resistant variants present in the parent strain. A range of such variants existed, decreasing in frequency as their degree of resistance increased. Examination of one that was resistant to moderate concentrations of streptomycin, (25 μg/ml) and a second that was resistant to high (100 μg/ml) concentrations of streptomycin suggested that both possessed ribosomes which had lower affinity for the antibiotic than those of the parent strain, and that tolerance to high levels of streptomycin was due to a resistant ribosomal system for protein biosynthesis.
Nitrogenase in synchronized Azotobacter vinelandii OP
Authors: Kurz W. G. W. , Larue T. A. , Chatson K. B.
Published: April 2010

Azotobacter vinelandii OP was synchronized by the continuous phased culture technique. The nitrogenase (nitrogen:(acceptor) oxidoreductase) (EC 1.7.99.2) activity of the culture was determined continuously within the fermentor by acetylene reduction. Addition of NH4+ in excess of 5 × 10−3 M to the culture lowered nitrogenase activity immediately. Other sources of fixed nitrogen had no immediate effect on nitrogenase activity, but nitrogenase synthesis decreased in the cell cycle following the one in which the fixed nitrogen was added.
Kinetics of yeast growth: inhibition-threshold substrate concentrations
Authors: Tseng Murray Men-chung , Wayman Morris
Published: April 2010

Two Candida species and a Saccharomyces were grown on ethyl alcohol, acetic acid, ethyl acetate, and 1-butanol, and their growth rates at a series of concentrations of each substrate are reported. Substrate concentrations higher than a characteristic threshold substrate concentration S0 inhibited growth in accordance with a new relationship:[Formula: see text]where i is an inhibition constant and the other symbols have their usual meanings. Complete inhibition, that is, no growth, takes place when S = Si, the total inhibition concentration. Values of S0, Si, and i were calculated for the examples studied. Also discussed are the observed lag periods and also the lowered yields at high substrate concentrations.
The influence of season and stage of development of plant on Endogone mycorrhiza of field-grown wheat
Authors: Saif S. R. , Khan A. G.
Published: April 2010

A quantitative and qualitative survey of the indigenous Endogone population in wheat field soil and vesicular-arbuscular mycorrhiza in wheat roots as influenced by season and by the stage of development of the wheat plant was made. The number of Endogone spores in wheat field soil remained relatively unchanged in winter until January during the period of vegetative growth and tillering of wheat plants. The spore number increased after the period of maximum root growth. The extent of mycorrhizal infection was related to the number of Endogone spores in soil. The extent of formation of arbuscules was influenced by the stage of development of the wheat plants.
The recovery of nocardial recombinants from broth cultures
Authors: Brownell G. H. , Runner R. R.
Published: April 2010

Broth culture media were examined for their ability to support growth and recombination between compatible strains of Nocardia erythropolis. Nutrient (Nut) and peptone – yeast-extract (PY) broths supported the production of recombinants after 36 h of incubation with a maximum recovery of about 6.0 × 10−1 CFU/ml. Cells mated in trypticase broth (TB) yielded the highest incidence of recombinants (1.0 × 10−2 CFU/ml) in the absence of parental cell growth. From a chemically defined mating broth (CD), supplemented with limited amounts of the parental-growth requirements, recombinant recovery reached about 1.0 × 10−4 after 120 h of incubation. The recombinant class types obtained from Nut- or PY-mated strains were predominantly auxotrophic while TB-mated strains produced stable prototrophs. The high incidence of recombinant types from TB-mated strains was due to growth of selected prototrophic classes. Studies with strains mated in PY broth indicate that the mating event occurs at very low frequencies between older, stationary-phase cells rather than between actively growing, log-phase cells.
Multiple-variant design for the enrichment of photosynthetic bacterial populations
Authors: Jeffries Thomas W. , Butler Richard G.
Published: April 2010

A design for the simultaneous variation of acetate, sulfide, and sulfate concentrations in 11 related media is described. Selectivity of these media by a direct enumeration technique in solid culture was compared with that for enrichment in liquid culture. Variation of nutritional parameters resulted in the selection of Rhodospirillaceae at initial enrichment concentrations of 0.1 g or less of Na2S∙9 H2O per litre and Chromatiaceae at 0.1 to 1.0 g of Na2S∙9 H2O per litre. The survival of sulfate-reducing and coliform bacteria indicated interdependency of photosynthetic populations with the former and competition with the latter. Photosynthetic bacteria selectively cultivated in liquid enrichment were tentatively identified as Rhodopseudomonas capsulata, Rhodopseudomonas spheroides, Chromatium warmingii, Chromatium okenii, Thiospirillum, and Rhabdomonas.
Chromosomal location of mutations affecting the regulation of biotin synthesis in Escherichia coli
Authors: Pai C. H. , Yau H.C.
Published: April 2010

The chromosomal locations of biotin regulatory mutations, birA, bioR, and dhbB, of Escherichia coli are determined by transduction using phage P1. All mutant genes are mapped between bfe and supM.
Staphylococcal polysaccharide products inhibitory to Staphylococcus aureus bacteriophage
Authors: Scheer E. R. , Koft B. W.
Published: April 2010

Four products derived from Staphylococcus aureus cultures were partially purified and tested for inhibitory activity against staphylococcal phage. Phage inhibition, a specific stable phenomenon, was concentration dependent. All inhibitory products contained carbohydrate and amino acids, the most active (phage 73 lysate product) having a high carbohydrate content. Galactose, glucosamine, five or six amino acids, and possibly 3-O-methylglucose and a uronic acid were found as components in all active preparations. However, the exact nature of the active material remains undetermined.
Germination of Bacillus cereus endospores: a proposed role for heat shock and nucleosides
Authors: Yousten Allan A.
Published: April 2010

Spores of Bacillus cereus T prepared in a glucose – yeast extract – salts broth germinated in L-alanine or more rapidly in L-alanine plus inosine or adenosine. The nucleosides alone were not germinative. Inosine was shown to produce no pregerminative changes in spores that prepared them for more rapid germination later in L-alanine. Experiments which measured the interaction of nucleosides, heat shock, and D-alanine on germination rates suggested that nucleosides may potentiate L-alanine-induced germination by causing discrimination against D-alanine at the L-alanine binding site(s) in the spore. D-Alanine is germinative when used with inosine probably because of L-alanine formation by alanine racemase. Heat shock, a prerequisite to D-alanine plus inosine-induced germination, may facilitate entry of inosine into the spore in amounts needed to discriminate against D-alanine.
Nutritional requirements of some non-pathogenic Neisseria grown in simple synthetic media
Authors: McDonald I. J. , Johnson K. G.
Published: April 2010

Ten species of non-pathogenic Neisseria were grown in simple defined liquid media containing amino acids, biotin, nicotinic acid, calcium pantothenate, ferrous sulfate, magnesium sulfate, and potassium phosphate. Two of these Neisseria were induced to grow with glutamic acid as the carbon and nitrogen source. The remaining eight Neisseria grew in glutamic acid medium supplemented with from one to four additional amino acids, lactate, or lactate and glucose. A strain of N. flavescens grew in the absence of added growth factors whereas the remaining nine species of Neisseria required either biotin or nicotinic acid; pantothenate was required by two and was stimulatory for three of these species. Use of carbohydrates by the non-pathogenic Neisseria in synthetic medium was tested. Two strains failed to use any of the 14 carbohydrates tested; one strain used only glucose; the remaining seven strains used fructose, glucose, maltose, and sucrose to varying degrees.
Phospholipids of Cladosporium resinae cultured on glucose and on n-alkanes
Authors: Kan Claudia M. L. , Cooney J. J.
Published: April 2010

Cladosporium resinae was grown on glucose, on n-dodecane, and on n-hexadecane. Total lipid was greatest in dodecane-grown cells and least in hexadecane-grown cells, while glucose-grown cells contained the most phospholipid and hexadecane-grown cells contained the least. Cells from all three media contained phosphatidylethanolamine and phosphatidylcholine as their major phospholipids, with lesser amounts of phosphatidylserine and traces of a cardiolipin-like compound. The major fatty acids associated with each phospholipid were palmitic acid and one or more 18-carbon unsaturated fatty acids. There was no correlation between n-alkane growth substrate and fatty acyl components of cellular phospholipids.
Isolation and characterization of a bacteriophage infective for a UDP-galactose-4-epimeraseless mutant of Escherichia coli
Authors: Pazoles Christopher J. , Kulpa Jr. Charles F.
Published: April 2010

A DNA bacteriophage, designated CP13, was isolated against Escherichia coli J5, a UDP-galactose-4-epimeraseless mutant of E. coli 0111:B4. Bacteriophage CP13 appears to be specific for rough bacterial strains. Adsorption studies with E. coli J5 grown with galactose show that the bacteriophage will not adsorb when complete lipopolysaccharide is present in the cell membrane. This indicates that lipopolysaccharide may be directly or indirectly involved with the receptor site for bacteriophage CP13. The bacteriophage DNA has a G + C content of 52%.
A microplaque reduction assay for human and mouse interferon
Authors: Campbell J. B. , Grunberger T. , Kochman M. A. , White Sandra L.
Published: April 2010

A microplaque reduction assay for human and mouse interferons is described, using plastic disposable multicompartmental plates with flat-bottomed wells of 6 mm in diameter. The procedure is rapid and reproducible and lends itself to a considerable degree of automation. Its potential application in other areas of virology, such as rapid screening of samples for virus content or assay of neutralizing antibodies, is also discussed.
Biological activity of phthalated endotoxin
Authors: Pistole Thomas G.
Published: April 2010

Glycolipid (GL) was extracted from a heptoseless mutant of Salmonella minnesota by a mixture of phenol, chloroform, and petroleum ether. The GL was subjected to treatment with either acetic anhydride or phthalic anhydride; a portion of the GL was untreated. Both of the chemically treated preparations as well as the parent GL were examined for biological activity in the following systems: mouse lethality assays, rabbit pyrogenicity assays, and rabbit skin assays. The results of these studies indicated that both treated preparations were less toxic in mice than the parent GL. Compared with saline-treated controls, rabbits pretreated with either of the modified preparations exhibited a reduced pyrogenic response to a subsequent challenge dose of the homologous material but no reduction when challenged with the parent GL. Pretreatment with the unaltered GL rendered rabbits tolerant to the homologous material and, to some degree, to the modified preparations. Rabbits immunized with any of the three GL preparations exhibited dermal toxicity responses comparable with those in untreated animals. Based on these findings, it was concluded that treating GL with either phthalic anhydride or acetic anhydride results in a product which is less toxic in mice and less pyrogenic in rabbits than the parent GL, but which also exhibits a loss of ability to render rabbits tolerant to challenge with untreated GL.
Taxonomie numérique de bactéries telluriques non fermentantes à Gram-négatif
Authors: Debette J. , Losfeld J. , Blondeau R.
Published: April 2010

A numerical analysis was carried out from a set of 165 telluric Gram-negative bacterial strains. The results allowed to join up 130 of them divided into eight phenons. Two of these phenons represent on their own 70% of the classified strains. The first of these phenons (52 strains) can be assimilated to the genus Pseudomonas in the fluorescent group; the second one (41 strains) offers some analogies with the Acinetobacter. A representative strain type of the latter phenon was retained for later taxonomic comparisons.
Valine, malic, and pyruvic dehydrogenase tests in the differentiation of Bacteroides
Authors: Funderburk Noel R. , Kester A. S.
Published: April 2010

Fifteen isolates of Bacteroides were tested for their ability to dehydrogenate a variety of amino acids and organic acids. A simple and rapid method was developed for detecting dehydrogenase activity using 2,3,5-triphenyl tetrazolium chloride as a hydrogen acceptor and indicator. The results indicate that the tests for valine, malic, and pyruvic acid dehydrogenases have value in differentiating organisms in this genus.
Assimilation of citric acid and adipic acid by the blue-green alga Anabaena variabilis
Authors: Butler M. , Capindale J. B.
Published: April 2010

The assimilation of [1,6-14C] citric acid and [1,6-14C] adipic acid by the blue-green alga Anabaena variabilis was studied in the dark and in the light. Citric acid was assimilated in the dark and in the light but adipic acid showed only limited assimilation in the dark. In the light the assimilation of adipic acid did not enhance the growth of the alga at a concentration of 2.85 × 10−8 M. Growth was inhibited at adipic acid concentrations greater than 10−3 M.Analysis of the products of adipic acid metabolism showed the presence of aspartic acid, glutamic acid, leucine, proline, and threonine amongst other unidentified compounds. A mechanism of β-oxidation is proposed.
The influence of hydrostatic pressure upon biochemical activities of heterotrophic bacteria
Authors: Albright Lawrence J.
Published: April 2010

Heterotrophic terrestrial and marine bacterial protein synthetic rates decrease by about 16% of the 1-atm rate for every 100 atm of pressure increment, within the pressure range of 1 to 500 atm. It is proposed that protein synthesis is more severely inhibited by pressure than are other anabolic or catabolic reactions.
Isolation and characterization of Actinopolyspora halophila, gen. et sp. nov., an extremely halophilic actinomycete
Authors: Gochnauer Margaret B. , Leppard Gary G. , Komaratat Prayad , Kates Morris , Novitsky Thomas , Kushner Donn J.
Published: April 2010

An actinomycete, isolated as a contaminant of a culture medium containing 25% NaCl, has been classified as Actinopolyspora halophila gen. et sp. nov. in the family Nocardiaceae. The morphology and biochemical characteristics of this organism distinguish it from other members of the family Nocardiaceae and other genera possessing a type IV cell wall. It requires high NaCl concentrations for growth and can grow in saturated NaCl. The lowest concentration permitting growth in liquid medium is 12%, and on solid medium, 10%. Colonies developing at lower salt concentrations contain holes resembling viral plaques. No growth occurred in a medium containing 30% KCl instead of NaCl. This organism can grow in simple media with NH4+ salts as nitrogen source and different sugars and other compounds as carbon source. Though it has a salt requirement almost as great as the extremely halophilic rods and cocci, it differs from these in containing diaminopimelic acid and in sensitivity to lysozyme; both properties suggest that it has a mucopeptide cell wall. It also contains some phospholipids common to other actinomycetes, but does not contain any phytanyl ether linked lipids characteristic of other extremely halophilic bacteria.
Enzymatic hydrolysis of agar: purification and characterization of neoagarobiose hydrolase and p-nitrophenyl α-galactoside hydrolases
Authors: Day D. F. , Yaphe W.
Published: April 2010

The mixture of polysaccharides in the gelling component of agar (agarose) is hydrolyzed to D-galactose and 3,6-anhydro-L-galactose by a series of hydrolytic enzymes obtained from Pseudomonas atlantica. The final degradative step in the pathway of agarose decomposition is the hydrolysis of the α-linkage in the dissaccharide neoagarobiose yielding D-galactose and 3,6-anhydro-L-galactose. Pseudomonas atlantica when grown on agar produces two specific enzymes, p-nitrophenyl α-galactose hydrolase and neoagarobiose hydrolase. The purification and partial characterization of both enzymes are presented.
Effect of growth temperature on the accumulation of glucose-oxidation products in Pseudomonas fluorescens
Authors: Lynch William H. , MacLeod Janet , Franklin Mervyn
Published: April 2010

The effect of the growth temperature, on the accumulation of glucose-oxidation products, was examined in aerated cultures with carbon excess in two strains of Pseudomonas fluorescens. At low growth temperatures (0 and 5 °C), 2-ketogluconate (KG) accumulated in the medium as the major oxidation product of glucose (up to 70%) before further metabolism. As the growth temperature was increased, the amount of 2-KG found to accumulate in the medium from glucose oxidation decreased. At a growth temperature of 20 °C, up to 25% of the glucose originally added accumulated in the medium as 2-KG. At the optimum growth temperature of 30 °C or above, no 2-KG was detected at any time during growth with glucose. Similar results were obtained when gluconate was used as the sole carbon and energy source.The results demonstrated a differential effect of growth temperature on the accumulation of oxidation products from glucose and gluconate. At low growth temperatures the major route for the catabolism of glucose and gluconate was the direct oxidative non-phosphorylated pathway.
Isolation and partial characterization of an Escherichia coli mutant resistant to colicin A
Authors: Lavoie Marc , Mathieu Leo G.
Published: April 2010

An Escherichia coli K12 mutant resistant to colicin A-CA31 apparently through loss of its receptor sites has been isolated and partially characterized. Resistance to colicin A was accompanied with a decreased sensitivity to colicins L-398 and E2-CA42, and to acridine dyes. The mutant strain displayed the same general pattern of tolerance or sensitivity as the parent strain towards eight antibiotics, colicins C, D, E1, E3, F2, F3, G, I, K, and N; phages T1, T2, T5, T6, T7, F2, λ vir, P1kc, [Formula: see text] 80, and BF23; and to methylene blue, triphenyltetrazolium chloride, ethylene-diaminetetraacetate (EDTA), deoxycholate, and sodium dodecyl sulfate. Conjugation and transduction experiments showed that a locus controlling resistance to colicin A-CA31 mapped at 21 min on the genetic map of this E. coli K12 strain.
Glycogen—a physiological determinant of yeast flocculation?
Authors: Patel G. B. , Ingledew W. M.
Published: April 2010

Evidence is provided to extend earlier observations that glycogen and flocculence levels vary concurrently in brewing yeast. The use of glycogen mutants, the alterations of growth conditions specifically to inhibit glycogen storage, and observations on glycogen decreases during endogenous metabolism have verified the above. A mechanism by which glycogen might exert its effect on flocculation is suggested.
Immunochemical studies of the surface and cytoplasmic membranes of Entamoeba invadens (Rodhain 1934)
Authors: McLaughlin J. , Meerovitch E.
Published: April 2010

The antigenic properties of cell fractions prepared from axenically grown Entamoeba invadens were investigated using various immunoelectrophoretic methods. All membrane fractions displayed varying degrees of antigenicity, the most predominant being a cytoplasmic light-vesicle fraction. The surface membrane showed the least diversified range of antigenic components and was also the least immunogenic fraction as judged by the reactivity of the antisera produced. Using tandem-crossed immunoelectrophoresis the antigenic profiles of the membrane fractions were compared.No evidence was obtained for the presence of either lipid or carbohydrate in the antigenic moieties of any of the membrane fractions. Using a series of sequential solvent extractions it was concluded that both divalent metallochelate linkages and interiorly located hydrophobic associations were principally involved in binding the major antigenic components within the light-vesicle membrane.An enzymic function was assigned to certain of the membrane antigens, the immunoprecipitates obtained showing both acid phosphohydrolase and non-specific esterase activity toward a variety of substrates.
The fine structure of conidial development in the genus Torula. I. T. herbarum (Pers.) Link ex S. F. Gray and T. herbarum f. quaternella Sacc.
Authors: Ellis D. H. , Griffiths D. A.
Published: April 2010

Conidiogenesis in Torula herbarum and T. herbarum f. quaternella was observed by scanning and transmission electron microscopy. Conidia of the former were shown to be made up of three equally sized cells capped by a distinctive, and easily recognizable, conidiogenous cell. Conidiogenous cells also arose terminally on erect hyphae and on prostrate hyphae. The single-layered conidial cell walls were differentiated into an inner hyaline zone and an outer electron-dense zone formed by the deposition of melanin. Conidiogenous cells lacked melanin at the apex and, before conidiation, the lateral walls were strengthened by a further deposition of melanin. The apex bulged outwards and was modified into a new multicelled conidium bearing another apical conidiogenous cell. Continued development of new conidia resulted in an acropetal chain which became disarticulated after cytolysis within the conidiogenous cell. The relative distinctions between holoblastic and enteroblastic development are discussed and it is concluded that the conidia should be referred to as blastoconidia.
A comparative study on the heat stability of triosephosphate isomerase in psychrophilic, psychrotrophic, and mesophilic Clostridia
Authors: Finne Gunnar , Matches Jack R. , Liston J.
Published: April 2010

The temperature stability of triosephosphate isomerase (EC 5.3.1.1) in the cell-free extracts of psychrophilic, psychrotrophic, and mesophilic Clostridium species has been investigated. Even though this enzyme was found to be heat labile in the psychrophilic isolates, no detectable loss in activity was evident when cell-free extracts were heated for ½ h at the maximum temperature of growth for the organisms. Two organisms, each with a maximum growth temperature of 23 °C, showed different heat stability of triosephosphate isomerase. However, a trend is evident that as the maximum growth temperature increases, the thermostability also increases. It is suggested that the heat liability of this enzyme is not a controlling factor in psychrophilism, but rather an adaptation to the cold habitat of these organisms.
The survival of Escherichia coli from freeze–thaw damage: permeability barrier damage and viability
Authors: Calcott Peter H. , MacLeod Robert A.
Published: April 2010

The effect of cooling rate and subsequent warming rate on survival of lactose-limited Escherichia coli was investigated. As previously reported, in the slow cooling rate range, a peak of survival was noted at 8 °C/min with survival decreasing as the cooling rate was increased or decreased from this value. Minimal survival was noted at 100 °C/min; increasing the cooling rate above 100 °C/min increased survival. At cooling rates greater than 200 °C/min, the survival became dependent on subsequent warming rates.Permeability damage, as measured by release of UV-absorbing material, potassium and β-galactosidase, and increased accessibility of glucose-6-phosphate dehydrogenase to its substrates, was dependent on the cooling rate when cells were frozen in either water or saline. For cooling rates less than about 8 °C/min, there was minimal permeability damage to cells frozen in water. However, at rates greater than this value, damage and viability were related; the lower the viability the more the damage to the permeability barrier. The relationship was strengthened by the observations that protectants which increased survival reduced damage as well and that at ultrarapid cooling rates where survivals were dependent on warming rates, the extent of damage was likewise dependent on the warming rate.Saline frozen cells were damaged by freezing and thawing more than comparable water-frozen cells over the whole cooling rate range. At cooling rates less than 8 °C/min, frozen in water, permeability damage of cells frozen in saline increased as the cooling rate decreased. As the cooling rate was increased from 8 °C/min, the damage increased as viability decreased.The relevance of these findings to the two-factor hypothesis of cell death is discussed.
Humoral antibody response to cattle to formalinized Staphylococcus aureus vaccine
Authors: Mukkur T. K. S. , Tewari Usha J.
Published: April 2010

Five cows were inoculated intradermally with formalinized Staphylococcus aureus suspension in Freund's complete adjuvant and the development of the humoral antibody response was followed as judged by the agglutination titer of sera, at various intervals post inoculation. Highest titers were observed at 78–87 days post inoculation. Agglutinating activity was found in IgM and IgG fractions (IgG1 and IgG2) of both serum and colostrum. The agglutinating activity of colostrum was significantly higher at 12 than at 24 and 36 h, post partum. However, no such activity was detected in either normal cow serum or colostrum against S. aureus.
Microbial petroleum degradation: application of computerized mass spectrometry
Authors: Walker J. D. , Colwell R. R. , Petrakis L.
Published: April 2010

An analytical procedure is presented for obtaining detailed characterization of petroleum hydrocarbons which undergo microbial degradation. The procedure includes column chromatographic separation and characterization of the resulting fractions by mass spectrometry and gas chromatography. The use of computerized low-resolution mass spectrometry is offered as a method for assessing microbial degradation of petroleum. This method provides information which cannot, at the present time, be obtained by other available analytical methods. Use of this method to evaluate degradation of a South Louisiana crude oil by a mixed culture of estuarine bacteria revealed that asphaltenes and resins increased by 28% after degradation, while saturates and aromatics decreased by 83.4% and 70.5%, respectively. Most of the normal and branched-chain alkanes were degraded (96.4%), but an increase in long-chain alkanes (C28–C32) after degradation was observed by gas–liquid chromatography. Susceptibility of cycloalkanes to degradation was less as the structure varied, i.e., 6-ring > 1-ring > 2-ring > 3-ring > 5-ring > 4-ring. Susceptibility of aromatic components to degradation decreased with increase in the number of rings, viz., monoaromatics > diaromatics > triaromatics > tetraaromatics > pentaaromatics. Aromatic nuclei containing sulfur were twice as refractory as non-sulfur analogs.
Bacterial growth in seafood on restaurant premises
Authors: Venkataramaiah Nirmala , Kempton A. G.
Published: April 2010

Operational guidelines for a chain of the newer type of seafood restaurants and take-out stores were derived from plots of bacteriological and trimethylamine changes during the preparation and storage of cod fillets, shrimp, and clams. If fish is to be defrosted at room temperature it should be washed and portioned within 14 h. Subsequent storage at 5 °C should not exceed 72 h and once removed from the refrigerator it should be fried within 3 h. New stores should consider improved methods of defrosting. Trimethylamine content was a more sensitive measure of quality loss than bacterial growth. Shrimp quality can be improved by emphasizing the way shells are removed because most of the contamination was external. Shrimp shelled while still frozen had the best potential keeping quality. Clam meat is handled less and is always held at 5 °C; but bacterial growth indicated that it should not be held on the premises for more than 3 days including the time necessary for defrosting. Batter prepared fresh daily can be left at room temperature. Frying can obliterate poor handling procedures, but adequate cooking is essential under any conditions. Clams are a gourmet item but the practice of cooking them lightly at customer request proved inadvisable.
Gas metabolism in ovine rumen cultures on a nitrogen-deficient medium
Authors: Jones G. A. , Taylor A.
Published: April 2010

Inocula of rumen fluid from sheep were grown on a medium of low nitrogen content under an oxygen-free atmosphere containing N2. The cultures produced methane and carbon dioxide. Hydrogen gas was utilized and the partial pressure of N2 decreased by 24% in 48 h. Assuming this N2 to have been reduced to metabolically available nitrogenous compounds, these account for about 0.2% of the sheep's daily need.
Characterization studies on the membrane-bound adenosine triphosphatase (ATPase) of Azotobacter vinelandii
Authors: Jurtshuk Peter , McEntire John E.
Published: April 2010

The adenosinetriphosphatase (ATPase) (EC 3.6.1.3) activity in Azotobacter vinelandii concentrates in the membranous R3 fraction that is directly associated with Azotobacter electron transport function. Sonically disrupted Azotobacter cells were examined for distribution of ATPase activity and the highest specific activity (and activity units) was consistently found in the particulate R3 membranous fraction which sediments on ultracentrifugation at 144 000 × g for 2 h. When the sonication time interval was increased, the membrane-bound ATPase activity could neither be solubilized nor released into the supernatant fraction. Optimal ATPase activity occurred at pH 8.0; Mg2+ ion when added to the assay was stimulatory. Maximal activity always occurred when the Mg2+:ATP stoichiometry was 1:1 on a molar ratio at the 5 mM concentration level. Sodium and potassium ions had no stimulatory effect. The reaction kinetics were linear for the time intervals studied (0–60 min). The membrane-bound ATPase in the R3 fraction was stimulated 12-fold by treatment with trypsin, and fractionation studies showed that trypsin treatment did not solubilize ATPase activity off the membranous R3 electron transport fraction. The ATPase was not cold labile and the temperature during the preparation of the R3 fraction had no effect on activity; overnight refrigeration at 4 °C, however, resulted in a 25% loss of activity as compared with a 14% loss when the R3 fraction was stored overnight at 25 °C. A marked inactivation (although variable, usually about 60%) did occur by overnight freezing (−20 °C), and subsequent sonication failed to restore ATPase activity. This indicates that membrane reaggregation (by freezing) was not responsible for ATPase inactivation. The addition of azide, ouabain, 2,4-dinitrophenol, or oligomycin to the assay system resulted in neither inhibition nor stimulation of the ATPase activity. The property of trypsin activation and that ATPase activity is highest in the R3 electron transport fraction suggests that its probable functional role is in coupling of electron transport to oxidative phosphorylation.
The influence of acridine dyes and caffeine on recovery from ultraviolet damage in Eudorina elegans
Authors: Kemp C. L. , Malloy K. M.
Published: April 2010

Caffeine and the acridine dyes, acridine orange and acriflavine, were used to examine the repair potential in Eudorina elegans following ultraviolet irradiation. Acridines blocked photoreactivation primarily as a result of absorption of photoreactivating wavelengths, but acridines did not influence dark survival. Therefore, an acridine-sensitive excision–resynthesis–repair process is absent in Eudorina.Caffeine decreased both dark and light survival, the latter only after relatively high doses of ultraviolet light were used for inactivation. The caffeine-sensitive repair process appears to function most actively when the organisms are engaged in DNA synthesis, indicating that a postreplication–repair system exists in Eudorina. However, the data suggest that a repair system not associated with the DNA synthetic phases may also exist.
The function of slime from Physarum flavicomum in the control of cell division
Authors: Henney Jr. Henry R. , Asgari Mortaza
Published: April 2010

A haploid cell of the myxomycete Physarum flavicomum undergoes cytokinesis, producing a large population of cells. However, after syngamy, cytokinesis no longer occurs but karyokinesis does and subsequent growth results in the formation of a diploid syncytial Plasmodium. Slime, which is produced by the Plasmodium but not the haploid cells, was aseptically isolated and purified, and tested for its effect as a cytokinetic regulator. Slime (a viscous, high molecular weight, acidic glycoprotein) affected cytokinesis of the haploid myxamoebae growing in pure culture in soluble media, and the effect was concentration dependent. In simple media, a slime concentration of about 6 × 10−5 μg protein per cell suppressed cytokinesis about 50%, unequally inhibited the synthesis of protein, RNA, and DNA, but stimulated respiration. The biological activity of slime was not species specific and it also affected the bacterium Bacillus subtilis by inhibiting cytokinesis, stimulating oxygen uptake, and producing an aberrant cell morphology. Slime was inactivated by heat, fragmentation, and incubation with dithiothreitol, mercaptoethanol, and the proteolytic enzyme papain (EC 3.4.22.2). The inhibitory effect of slime on cell division of haploid cells could not be achieved using mucin or various polyanions. The possible role of slime in the production of the diploid syncytium is discussed.
A technique for obtaining linear heat-survivor curves with Staphylococcus aureus and its application to the assay of sublethal heat injury
Authors: Hurst Andre , Hughes Ashton , Whitfield Georgia
Published: April 2010

Staphylococcus aureus was grown in a complex (HK) medium either by a batch technique or by a modified batch technique after growth in a chemostat. These cultures were heat-treated at 52 °C, and counted on trypticase soy agar (TSA) or trypticase soy agar containing 7.5% NaCl (TSAS). When linear heat-survivor curves were obtained decimal reduction times (D52°C) could be calculated from the TSA counts and pseudodecimal reduction times (D′52°C) from the TSAS counts. The D or D′ values of batch-grown cells varied from 22 to 133 min and from 3 to 12 min, respectively. With cells grown by the modified technique the values were less variable (D was 22–51 min and D′ was 3–7 min). D and D′ values could be calculated from the same heat treatment in two of six estimations with batch-grown cells but in six of six estimations with cells grown by the modified technique.
Methods for growing nitrogen-fixing bacteria separated from plant cells
Authors: LaRue T. A. , Kurz W. G. W. , Child J. J.
Published: April 2010

Methods are described for growing dinitrogen-fixing rhizobia in the presence of plant cells.