bluuebunny/crossref_metadata_2025 huggingface dataset:
ELECTRON MICROSCOPY OF THE BACTEROIDS AND ROOT NODULES OF LUPINUS LUTEUS
Authors: Jordan D. C. , Grinyer I.
Published: February 2010

No intracellular infection threads were observed in ultrathin sections of young root nodules of lupine, although nodule bacteria could be found in the intercellular spaces between the root cortical cells. Evidence suggests that in certain instances the plant cell walls can be disrupted locally, allowing the bacteria to pass into cytoplasm of the host cell. The spread of infection may be initiated in this manner and extended by division of infected cells. No plant-produced enclosing membranes were present around bacteria in the intercellular spaces but such structures developed after the bacteria had entered the plant cell. Although the origin of these membranes is debatable, in the present work it appeared that they were formed de novo, perhaps in a manner akin to the development of the cell plate during cell division. Most of the bacterial cells possessed a wide subwall space lying between the bacterial cell wall and plasma membrane. Discontinuities present in the latter membrane may account for the ribosome-like material found in the subwall space.
STUDIES ON THE EXTRACELLULAR PROTEOLYTIC ENZYMES OF RHIZOPUS OLIGOSPORUS
Authors: Wang Hwa L. , Hesseltine C. W.
Published: February 2010

Two proteolytic enzyme systems were observed in the culture filtrates of Rhizopus oligosporus. One has an optimum pH at 3.0; the other, at 5.5. Both enzyme systems have maximum activities at 50–55 °C and are fairly stable at pH 3.0–6.0. Maximum production of the enzymes occurred after 72 to 96 hours of incubation and then it decreased rapidly. Higher proteolytic activity was noted in the culture filtrates of the organism grown in wheat flour medium than in soybean flour. Data suggest that formation of the enzyme systems appears to be inhibited by soybean extracts.
INFLUENCE OF THE MICROPHYSICAL STRUCTURE OF A SYSTEM ON THE GROWTH OF BACTERIA
Authors: Miller Raymond J. , Davey C. B.
Published: February 2010

Multiplication of bacteria grown in three different physical systems: basal liquid medium, medium plus agar in the sol state, and medium plus agar in the gel state, all at 39.94 ± 0.05 °C, revealed that the growth of organisms is strongly influenced by their microphysical environment. Not only was the final number of bacteria affected but their morphology was also changed. It is suggested that these effects may be due in part to a quasi-crystalline structure of the water around agar in the gel state which reduces the fluidity of the water, the distribution of the bacteria, and the mobility of nutrient ions.
SPORULATION OF BACILLUS POPILLIAE ON SOLID MEDIA
Authors: Rhodes R. A. , Roth M. S. , Hrubant G. R.
Published: February 2010

Spores of the insect pathogen Bacillus popilliae Dutky have been formed in vitro from vegetative cultures. The procedure results reproducibly in 0.1 to 0.3% spore formation in cells of colonies grown on a solid medium under strictly denned conditions. Sporulation requires a selected strain of the organism, NRRL B-2309S, a relatively large and specific concentration of certain yeast extracts, a specific type of agar, the complete absence of glucose, the presence of acetate, and a pH within the range 7.2 to 7.5. Spore formation occurs slowly during 2- to 4-week incubation periods in surface colonies present in limited numbers on agar plates. Some of the spores formed in this manner survive heating for 15 minutes at 80 °C, and vegetative cultures derived from such spores are pathogenic via injection for larvae of the Japanese beetle, Popillia japonica Newman.
BIOSYNTHESIS OF EXTRACELLULAR POLYSACCHARIDES BY THE BLUE-GREEN ALGA ANABAENA FLOS-AQUAE
Authors: Moore B. G. , Tischer R. G.
Published: February 2010

Extracellular polysaccharides were isolated from the blue-green alga Anabaena flos-aquae strain A-37. The polysaccharides are composed of glucuronic acid, glucose, xylose, and ribose in a molar ratio of 1:88:39:3. The extracellular polysaccharides comprise about 40% of the total carbohydrate produced by this alga.Carbon utilization experiments revealed that only D-fructose could be substituted for carbon dioxide as a precursor of polysaccharides and cellular material.The extracellular polysaccharides are derived from water-soluble intracellular polysaccharides of the same composition.Fructose accumulates in stationary phase cells grown in CO2and the presence of the enzymes fructose diphosphate phosphatase and fructose diphosphate aldolase was demonstrated. Tracer studies showed the presence of phosphorylated compounds common to the photosynthetic carbon reduction cycle and the glycolytic pathway.
ACETOLACTATE FORMATION BY STREPTOMYCIN MUTANTS OF ESCHERICHIA COLI
Authors: Coukell M. B. , Polglase W. J.
Published: February 2010

The activity of the enzyme system which forms acetolactate in Escherichia coli was found to be greater at both pH 6 and at pH 8 in streptomycin-dependent mutants than in the parent sensitive cultures. The activity of the acetolactate-forming system was observed to be lower in a streptomycin-sensitive revertant than in the dependent E. coli culture from which it was derived by back-mutation. The activity of the acetolactate-forming system from streptomycin-resistant (indifferent) mutants was within the range found for streptomycin-sensitive cultures and was not affected by growth in medium containing dihydrostreptomycin. It was concluded from these observations that excretion of L-valine by streptomycin-dependent E. coli was a consequence of the elevated acetolactate-forming activity of these mutants. To explain the (apparently specific) elevation of the acetolactate-forming system in streptomycin-dependent cells, it was postulated that the antibiotic functioned as a de-repressor while pyruvate functioned as the specific enzyme inducer.
RELATION OF SOME ENVIRONMENTAL FACTORS TO GROWTH OF SEVERAL NEMATOPHAGOUS HYPHOMYCETES
Authors: Olthof Th. H. A. , Estey R. H.
Published: February 2010

In vitro growth studies showed that Arthrobotrys oligospora Fresenius, A. conoides Drechsler, A. musiformis Drechsler, and A. robusta Duddington are characterized by a fast, inherent growth rate relative to A. dactyloides Drechsler, Dactylella gephyropaga Drechsler, and Dactylaria brochopaga Drechsler, which grew slowly on all media tested. Arthrobotrys superba Corda, Dactylella ellipsospora Grove, and D. asthenopaga Drechsler were found to be intermediate in this respect. There was little correlation between the maximum rate of increase in colony diameter of the 10 species of nematophagous Hyphomycetes and their ecological requirements for such growth. The fast-growing species appeared to prefer media with a pH range of 5.0–6.0 and the slow-growing fungi a pH of about 4.0. No consistent similarity in environmental requirements was found among species of fungi belonging to the same genus or between those possessing the same kind of nematode-trapping organ. Lima bean agar of pH 5.0 was a satisfactory culture medium and incubation at 25 °C in continuous or intermittent light resulted in larger colonies than incubation in darkness.
CELL WALL REPLICATION IN SACCHAROMYCES CEREVISIAE
Authors: Chung K. L. , Hawirko R. Z. , Isaac P. K.
Published: February 2010

Cell wall growth and bud formation in Saccharomyces cerevisiae was studied by labelling with fluorescent antibody. Labelled cells were grown in a glucose yeast extract broth and examined at 15-min intervals. The new cell wall was largely non-fluorescent while the old wall showed no reduction of fluorescence during growth of the bud. Bud formation was initiated as a small bulge on the cell wall, and further increase in size was accompanied by the formation of a constriction around the basal end which led to the separation of the bud from the mother yeast cell. The actively growing area of the bud was an annular band close to the base. It appears that the cell wall of the bud was, almost entirely, newly synthesized and contained very little old cell wall material. The process of wall synthesis is compared with the pattern found in several bacteria and with what is known of the process in other fungi.
A STUDY OF SOME ASPECTS OF SULFUR METABOLISM IN THE WOOD-ROTTING BASIDIOMYCETE, FOMES GEOTROPUS
Authors: Lougheed G. J. , Milazzo F. H.
Published: February 2010

The requirement of an inorganic sulfur source for the growth of Fomes geotropus was demonstrated. Inorganic sulfate supported growth to a greater extent than the other more reduced forms of sulfur: sulfite, thiosulfate, sulfide, and taurine. The presence of a sulfate-activating mechanism involving the active sulfate intermediate 3′-phospho-adenosine-5′-phosphosulfate was indicated. In addition, study of the uptake and incorporation of radioactive sodium sulfate revealed that inorganic sulfur was assimilated into the organic sulfur compounds methionine and cyst(e)ine.
GROWTH AND SURVIVAL OF HISTOPLASMA CAPSULATUM IN SOIL
Authors: Goos R. D.
Published: February 2010

Growth and survival of Histoplasma capsulatum, a fungus pathogen of man, in sterilized and non-sterile soil was determined. Growth in sterilized soil, as determined by plate counts, was favored by increasing moisture levels up to 85% of the water-holding capacity of the soil, and by the addition of several organic materials, including peptone, grass clippings, purified chitin, and chicken feces. The fungus survived for at least 8 weeks when introduced into non-sterile soil as conidia. Addition of organic amendments were not necessary for survival, and may, in fact, have been deleterious. Disappearance of the fungus from unsterile soil in some experiments suggests that it is sensitive to antagonistic biological effects. The fact that non-amended soils were as favorable for survival as were soils amended with chicken feces, or other organic materials, suggests that the search for natural habitats of this fungus should not be limited to bird roosting sites.
A COMPARISON OF METHODS FOR THE ISOLATION OF FUNGI FROM RHIZOSPHERES
Authors: Parkinson D. , Thomas A.
Published: February 2010

A comparison was made between the fungi isolated from non-rhizosphere soil and from rhizosphere soil of mature dwarf bean plants by three methods of isolation: soil dilution plating, soil plating, and soil washing followed by the plating of washed soil particles. The data obtained with rhizosphere soil demonstrated that the use of the soil-washing technique allowed an increased frequency of isolation of sterile forms, Fusarium spp., and members of the Mucorales, whereas heavily sporing forms were isolated with decreased frequency. It is concluded that, compared with other isolation methods, the soil-washing technique allows a more accurate assessment of fungi active in the rhizosphere.
THE INDUCTION BY LYSOZYME OF AN L-TYPE GROWTH IN MYCOBACTERIUM TUBERCULOSIS
Authors: Willett Hilda Pope , Thacore Harshad
Published: February 2010

Lysozyme in combination with ethylenediamine tetraacetic acid (EDTA) gives rise to spheroplasts when Mycobacterium tuberculosis is cultured in a nutritionally complete Tween 80 – albumin medium. These spheroplasts do not multiply in this medium, but when such forms, stabilized by the presence of sucrose and Mg++, are inoculated into PPLO agar or broth an L-form of growth is initiated. A CO2requirement was demonstrated by L-forms grown on solid media.
CONCERNING THE MECHANISM BY WHICH HADACIDIN POTENTIATES THE DAMAGING ACTION OF IONIZING IRRADIATION ON BACTERIA
Authors: Pittillo Robert F. , Bannister Edward R. , Johnson Elwanda P.
Published: February 2010

The potentiation of radiation damage by hadacidin in proliferating E. coli has been investigated. Apparently this effect of hadacidin may be due to an effect in previously described mechanisms of inhibition by hadacidin: (a) inhibition of adenylosuccinate synthetase and (b) undefined inhibition of energy production. E. coli cells grown in the presence of adenylic acid, adenine, oxalacetic acid, or anthranilic acid for 4 hours before exposure to radiation are insensitive to the hadacidin radiation effect.
METABOLIC INJURY TO BACTERIA: I. EFFECT OF FREEZING AND STORAGE ON THE REQUIREMENTS OF AEROBACTER AEROGENES AND ESCHERICHIA COLI FOR GROWTH
Authors: MacLeod Robert A. , Smith Lloyd D. H. , Gelinas Roger
Published: February 2010

Various complex supplements including Bacto-casamino acids when added to a minimal salts glucose medium increased the bacterial count on suspensions of cells of both Aerobader aerogenes and Escherichia coli frozen and stored for 3 weeks. Replica plating procedures established that no auxotrophic mutants had been formed. Attempts to fractionate Casamino acids revealed that the active material could be retained by and eluted from both acidic and basic ion exchange resins. A mixture of 18 crystalline amino acids was equally as good as Casamino acids as a supplement to the minimal medium for A. aerogenes. Cystine was the most effective of the amino acids in the mixture tested singly, though other amino acids singly and in combination also increased the bacterial count. Cysteine was even more active than cystine and as effective as the Casamino acids for both organisms. Ethylenediaminetetraacetic acid had some activity for A. aerogenes but little for E. coli. Cells frozen and stored were more sensitive to added phosphate in the medium than unfrozen cells. It is postulated that freezing and storage damage the cytoplasmic membrane of a proportion of the cells rendering them more penetrable by toxic metal ions present as trace contaminants. The enriched medium would permit growth of damaged cells by providing compounds capable of chelating the toxic ions.
CELLULAR CHANGES ACCOMPANYING THE SWARMING OF PROTEUS MIRABILIS: II. OBSERVATIONS OF STAINED ORGANISMS
Authors: Hoeniger Judith F. M.
Published: February 2010

This paper describes the changes in nuclear complement, cytoplasm, and cell wall which take place when short rods of Proteus mirabilis differentiate into long swarmers. In the swarmers themselves, definite cellular units are mapped out at intervals of 1.2 to 1.8 μ. These units consist of a nucleus (or paired nuclei) and the adjacent cytoplasm, there being apparently no cross septa between successive units. The cytology of the swarmers has been compared with that of long forms of P. mirabilis induced by penicillin, lithium chloride, ultraviolet light, and gamma radiation. Depending on the inducing agent and dosage, such long forms frequently have abnormal-looking nuclei and malformed cell walls, and thus contrast strikingly with the spontaneously arising swarmers.
VERTICAL DISTRIBUTION OF MYCOSTASIS IN MALAYAN SOILS
Authors: Griffiths D. A.
Published: February 2010

Using the cellulose-film method the distribution of mycostasis was examined in profiles from five differing soil types in Malaya. Soils were found to be inhibitory to the spores of Mucor ramannianus Möller to a depth of 360 cm, but waterlogged soils were less inhibitory than those which were drained. The addition of 1% (w/v) glucose only partially masked the inhibition in some soils while autoclaving the soils before assay resulted in a complete removal of the inhibition from the upper soil layers only. It was suggested that the mycostatic factor produced in the soil as a result of biological activity only extends down to a depth of 120–150 cm, whereas deeper layers in the profile possess an inhibitory factor which is non-biological in nature. The pattern of soil mycostasis was compared with those established for Nigerian and British soils and it was concluded that the pattern in Malayan soils resembled more closely that from Britain.
BIOASSAY OF SEAWATER: I. A 14C UPTAKE METHOD FOR THE DETERMINATION OF CONCENTRATIONS OF VITAMIN B12 IN SEAWATER
Authors: Carlucci A. F. , Silbernagel S. B.
Published: February 2010

A method is described employing 14CO2 uptake by the marine centric diatom Cyclotella nana (clone 13-1) for the bioassay of vitamin B12 in seawater. Seawater samples were filter sterilized, supplemented with sterile medium constituents, and diluted with a similarly supplemented, charcoal-treated filtered seawater. Samples or diluted samples, internal standards, and external standards were inoculated with the diatom such that the initial concentration of cells was approximately 1 × 104 per milliliter. The bioassay flasks were incubated for 47 hours, 14C as Na214CO2 was added, and 14C assimilation was measured after a 2-hour exposure. The rate of uptake of 14C could be related to B12 concentrations when these were in the range of 0.05 to 3.0 μμg B12 per milliliter. A 49-hour incubation time was selected since cells required time to adapt to seawaters collected from different locations. The concentration of B12 in a seawater sample was calculated from the radiocarbon uptake, the percentage of the internal standard recovered, and the dilution factor. The method is more sensitive than that described by Gold from which it was derived, and takes into account the serious inhibitory effects found in many samples of natural seawater. The limit of sure detection is about 0.05 μμg B12 per ml and the standard deviation of the method was about 0.3 μμg per ml when measuring 1.4 μμg B12 per ml in inhibitory seawater.
A NEW PROCEDURE FOR THE DETECTION AND ENUMERATION OF COAGULASE-POSITIVE STAPHYLOCOCCI FROM FROZEN SEAFOODS
Authors: Raj H.
Published: February 2010

A two-step procedure in which a new anaerobic liquid medium is used for a presumptive test and a solid medium (staphylococcus medium No, 110 fortified with egg yolk) incubated at 45 °C for a confirmatory test has been developed for the detection and enumeration of coagulase-positive staphylococci in frozen seafoods. The presumptive liquid medium called "Mannitol Salt Sorbic acid broth" provides specific enrichment to coagulase-positive staphylococci even in the presence of large numbers (104–105 cells) of mixed flora common to these foods. The addition of seafood material to the above medium does not affect its selective performance or its sensitivity. Also, the medium is equally efficient in recovering very low numbers of coagulase-positive staphylococcus subjected to freezing, even in the presence of the mixed flora. Incubation at 45 °C in the confirmatory step not only gives an accelerated egg yolk precipitation reaction typical of coagulase-positive staphylococci, but also enhances the specificity of the procedure.
A WIDE-SPECTRUM ANTIBIOTIC PRODUCED BY A SPECIES OF SORANGIUM
Authors: Peterson E. A. , Gillespie D. C. , Cook F. D.
Published: February 2010

A soil-borne myxobacter identified as a species of Sorangium produced a potent antibiotic capable of inhibiting growth of a wide variety of microorganisms including Gram-positive and Gram-negative bacteria, fungi, actinomycetes, and yeasts. The active material was readily isolated from culture fluids of the organism by ether extraction or by adsorption on a resin. A high degree of purity was achieved chromatographically. Acetone, methanol, or aqueous solutions of the antibiotic were stable when stored at low temperature (4 °C). At 70 °C it was unstable in phosphate buffer but retained its activity in iris buffer at neutral and alkaline pH.
FORMATION OF HEMOLYSIN BY STRAINS OF PSEUDOMONAS AERUGINOSA
Authors: Altenbern Robert A.
Published: February 2010

Hemolysin is formed in sonic extracts of cells of Pseudomonas aeruginosa by the action of a heat-labile substance, probably an intracellular "release" enzyme, on a substrate from the disrupted cell. The substrate and most of the hemolysin released can be sedimented by high-speed centrifugation. Hemolysin-negative strains appear to possess no release enzyme but do contain the substrate since addition of particulate matter to extracts of hemolysin-positive cells increases the rate and extent of hemolysin formation. The rate of hemolysin release in sonic extracts is strongly influenced by the concentration of the two reactants, and minor dilution abolishes all activity. There is only a small amount of release enzyme and substrate present in 24-h cells but increasingly greater amounts appear in extracts of 48- and 72-h cells. The hemolysin-forming system is sensitive to heat and is inactivated in 2 min at 100°. Treatment of particulate matter with lysozyme plus EDTA does not reduce the amount of hemolysin released by subsequent exposure of the particles to the release enzyme present in fresh sonic extract.
SPHEROPLAST INDUCTION AND LYSIS OF BCG STRAINS BY GLYCINE AND LYSOZYME
Authors: Sato H. , Diena B. B. , Greenberg L.
Published: February 2010

Spheroplast induction and lysis of 6 BCG strains of Mycobacterium tuberculosis by glycine and lysozyme was studied in various media. Spheroplast production was noted in only three strains involving 20% of cell populations. Lysis, as distinct from spheroplast induction, occurred in Dubos medium containing 1.5% glycine and 0.01% lysozyme after 24–48 hours of incubation. Estimation from a standard curve indicated 40 to 70% lysis of the total cell population after 7–10 days of incubation.Similarly, lysis of BCG cells occurred when the inducers, glycine, lysozyme, and lithium chloride, were added to nitrogen-starved cultures grown in Aldridge synthetic medium for 7 to 8 days.
MEDIUM SUPPLEMENTATION WITHL- ANDD-AMINO ACIDS RELATIVE TO GROWTH AND EFFICIENCY OF RHIZOBIUM MELILOTI
Authors: Strijdom B. W. , Allen O. N.
Published: February 2010

Five strains of Rhizobium meliloti serially cultivated on a basal yeast water mannitol mineral salts medium supplemented with increments of nine amino acids, respectively, produced ellipsoidal, bacteroidal, and elongated cell forms. Colonies produced on media containing D-amino acids and glycine were smaller and less opalescent than were those on the basal medium. Growth of two strains on media supplemented with the L-isomers of alanine, histidine, and phenylalanine, respectively, exceeded that in media to which the D-isomers of these amino acids were added. Growth was negative or sparse in the basal medium supplemented with 0.075% L-cysteine. Serial cultivation in media containing increments of D-cysteine, D-alanine, D-phenylalanine, and glycine produced the maximum loss in nitrogen-fixing ability; L-alanine and L-histidine were the least deleterious. Four strains became ineffective after serial cultivation on at least two of the nine amino acid media. The infective and nitrogen-fixing properties of an ineffective strain were unchanged after cultivation in amino acid supplemented media.
THE PURIFICATION AND PROPERTIES OFD-ALLOSEPHOSPHATE ISOMERASE OF AEROBAGTER AEROGENES
Authors: Matsushima K. , Simpson F. J.
Published: February 2010

Aerobacter aerngenes produces an inducible D-allose 6-phosphate ketol isomerase that nonspecilically isomerizes ribose 5-phosphate. The isomerase was separated from other isomerases present in extracts of cells grown on D-allose by repeated precipitation with protamine. Eighty percent of the activity of the purified preparation was lost on storage at 0 °C for 48 hours. The enzyme was most active and most stable at pH 8.5 and most active at 40 °C. Cobalt, manganese, magnesium, and phosphate ions inhibited at 0.05 M. Mercuric chloride, p-chloromer-curiphenylsulfonate, and iodoacetate also inhibited the isomerase but this was prevented by the addition of cysteine or reduced glutathione. These thiols also reactivated the enzyme when activity was lost during dialysis. 6-Phosphoallonate was a strong inhibitor and to a lesser degree 6-phosphogluconate, 6-phosphoglucosamine, 5-phosphoribonate, and erythrose 4-phosphate. For allose 6-phosphate Kswas 1.2 × 10−3 M and for ribose 5-phosphate, 4.5 × 10−3 M.
AN EFFICIENT GENERAL-PURPOSE CULTURE MEDIUM FOR AEROBES AND ANAEROBES
Authors: Khairat Omar
Published: February 2010

Thirty-three microbial strains (all but one freshly isolated from human pathologic material) and comprising aerobes, anaerobes, and CO2-dependent bacteria, were used to compare the growth capabilities of a new general-purpose medium, with two commonly used media; a heart infusion and a soy agar.The author"s new medium proved superior since it grew organisms (for example a pneumococcus) that failed to grow, even from massive inocula, on the two other media. A strictly anaerobic streptococcus from a bacteremia grew aerobically on the surface of the author"s medium while massive inocula of the same anaerobe failed to grow even anaerobically on the two other agar media. When colony size was compared (2070 colonies were measured) the author"s medium proved superior for 29 of the33 organisms tested.The soy agar medium gave poor α-hemolysis with pneumococci and viridans streptococci when compared with the two other media. The synergistic effect of both liver digest and yeast extract used in the author"s medium, and the heat-stable growth factors derived from them, are believed to be responsible for its superiority as a general-purpose medium for both aerobes and anaerobes.
RENVERSEMENT PAR LA THIAMINE ET LE PYRIDOXAL DE L"INHIBITION PRODUITE PAR L"HYDROXY-3 THALIDOMIDE SUR LA CROISSANCE D"ESCHERICHIA COLI
Authors: Jasmin Roland , Johnson Willard J.
Published: February 2010

Thalidomide and several of its derivatives, including 3-hydroxythalidomide, were tested as inhibitors of the growth of Escherichia coli. Only 3-hydroxythalidomide proved to be effective in this respect. Thiamine and pyridoxal when added in combination, but not singly, provided complete protection against the growth inhibitory effect of 3-hydroxythalidomide. Our results suggest the possibility that the latter may act by inhibiting the synthesis of both thiamine and pyridoxal.
TAXONOMY OF ENTEROCOCCI BY COMPUTER ANALYSIS
Authors: Raj H. , Colwell R. R.
Published: February 2010

A total of 48 pure cultures of Streptococcus (including 12 ATCC strains) belonging to the fecal, pyogenic, and viridans groups was studied in an effort to derive a numerical taxonomy of the enterococci based on Adansonian principles. Each of these cultures was subjected to a variety of tests. The data so obtained was encoded and analyzed by electronic computers, ft showed two major taxonomic groups: a large homogeneous cluster of all enterococcal strains tested and a discrete cluster of streptococci belonging to the pyogenic and viridans groups, showing the least cross relationships with all of the enterococcal strains including S. bovis. The large enterococcus group comprised S. faecalis, unclassified enterococci, S. bovis, S. durans, and S. faecium within the major group. The S. faecalis cluster of strains showed three discernible subgroupings of S. faecalis (typical), var. liquefaciens, and var. zymogenes. The "unclassified" types formed a rather homogeneous cluster which may warrant formal recognition as a separate species. S. bovis was most closely related to the unclassified species group. The results of analysis support the proposed determinative classification of enterococci (16).
BIOLOGICAL ACTIVITIES OF HAMYCIN
Authors: Maniar A. C. , Mavdikar Sarala
Published: February 2010

After ad ministration of an oral dose to mice, hamycin, an antifungal antibiotic, penetrated the body tissues and eliminated Cryptococcus neoformans present in the lungs. Out of 11 polyenes (hamycin, aureofungin, trichomycin, etruscomycin, amphotericin B, pimaricin, mycostatin, candidin, candicidin, PA150, and filipin), hamycin and aureofungin showed the highest "in vitro" activity against Candida albicans. The antifungal activity of hamycin, PA150, and aureofungin was increased by the addition of serum, plasma, or crystalline albumins. This increase in activity can be used as an additional characteristic to differentiate some of the polyenes. We now believe that serum was responsible for our previous findings that "high concentrations of hamycin in the organs of mice were detected". It has been shown that the complete albumin molecule was required to increase the activity of hamycin. The possibility that serum globulins or other proteins may increase the hamycin activity is not ruled out by our experiments.
THE EFFECT OF TEMPERATURE ON TOXIN FORMATION AND TOXIN STABILITY OF CLOSTRIDIUM BOTULINUM TYPE E IN DIFFERENT ENVIRONMENTS
Authors: Abrahamsson Kerstin , Gullmar B. , Molin N.
Published: February 2010

Clostridium botulinum type E was found to produce toxin at temperatures between 3° and 30 °C in Robertson"s chopped meat medium and in fish dialyzate. Toxin was produced more rapidly in the meat medium. No toxin was found after 1 year of incubation at 1 °C. At 3 °C a slight toxin production was noticed after 120 days, when the inoculum consisted of a mixture of vegetative cells and spores.The lowest concentration of NaCl necessary to inhibit toxin production was found to vary with the incubation temperature and duration of storage. The inhibiting effect of NaCl was more pronounced at lower temperature.Type E spores mixed in fish meat medium heated for 110 min at 80 °C or for 10 min at 90 °C produced toxin during prolonged storage at 20 °C but not after they were heated at 90 °C for 20 min.Toxin (type E) proved more thermostable in meat broth and fish dialyzate than in phosphate buffer solution or in buffer supplemented with gelatine. In meat broth the toxin was inactivated after 5 min at 65 °C.
THE MICROFLORA OF RAW BULK TANK MILK
Authors: Jackson H. , Clegg L. F. L.
Published: February 2010

Milk samples from 141 farms were plated on standard plate count agar and the colony count determined after incubation for 48 hours at 32 °C. Twenty colonies were picked at random from plates containing between 30 and 300 colonies. The isolates were inoculated into litmus milk and subsequently characterized on the basis of shape, Gram-staining reaction, catalase production, lactose fermentation, and the ability to form spores.Certain general trends in the flora were observed. In milk of a colony count less than 2 × 104 per ml, micrococci were the dominant group of organisms, and as the colony count of the milk increased the percentage of micrococci decreased and the percentage of Gram-negative rods and streptococci usually increased. In spite of these general trends a study of the flora of individual samples showed that quite marked variations did occur.
INDUCTION AND REPRESSION OF ENDOPOLYGALACTURONASE SYNTHESIS BY PYRENOCHAETA TERRESTRIS
Authors: Keen N. T. , Horton J. C.
Published: February 2010

Endopolygalacturonase (endo-PG) synthesis was inducible in standing and replacement liquid culture by Pyrenochaeta terrestris. Inducers were galacturonic acid, its polymers (pectin and polypectate), and structural relatives (mucic acid, tartronic acid, and dulcitol). On pectin, fungus growth and endo-PG synthesis were proportional to initial pectin concentration.Synthesis of endo-PG on pectin was stimulated by hexose supplements at 0.005 M and repressed by supplements at 0.05 M and above. Thus, repression of induced endo-PG synthesis was not dominant at low supplement concentrations as was found for induced cellulase synthesis by the same organism. This suggests that the production of endo-PG by the parasite during pathogenesis is less repressed by host sugars than is cellulase synthesis.
THE UTILIZATION OF TRYPTOPHAN IN THE BIOSYNTHESIS OF ECHINULIN
Authors: MacDonald J. C. , Slater G. P.
Published: February 2010

Aspergillus amstelodami was grown on molasses medium to which was added DL-tryptophan, labeled with 14C in the 2 position of the indole ring or in the carboxyl, α, or methylene carbons of the alanine side chain. All of these labeled compounds were incorporated by the organism to a significant extent into echinulin. Carboxyl-14C-labeled DL-tryptophan was incorporated into echinulin without appreciable randomization of radioactivity. Methylene-14C-labeled L-tryptophan was used to a greater extent in the biosynthesis of echinulin than was the D-isomer. Both the D- and L-isomers were used more efficiently in the synthesis of fungal tryptophan than for the synthesis of echinulin.
BACTERIA CAN PENETRATE ROCK
Authors: Myers G. E. , McCready R. G. L.
Published: February 2010

A method is described for studying the penetration of bacteria in intact rock cores. The test microorganism (Serratia marcescens ATCC No. 274) was labelled with radioactive phosphorus (32P) and suspended in sterile demineralized water. The cell suspension was allowed to enter the epoxy-coated rock core under atmospheric pressure. Penetration and migration of the labelled microorganisms were followed by measuring the radiation emitted at ports drilled through the epoxy coating, at various locations throughout the length of the core, and at various intervals of time after the beginning of the experiment. When migration was considered to be complete the core was aseptically split longitudinally and the results of the radiation studies confirmed by autoradiogram and culture. S. marcescens passed through 14.25 in. of Berea sandstone (the longest core available), and through 3-in. cores (longest available) of Mississippian limestone, Early Devonian limestone, and Late Mesozoic sandstone. The significance of these findings is discussed with respect to presence of so-called prehistoric microorganisms in geological specimens.
EXTRACELLULAR HETEROPOLYSACCHARIDES FROM CRYPTOCOCCUS AND TREMELLA: A POSSIBLE TAXONOMIC RELATIONSHIP
Authors: Slodki M. E. , Wickerham L. J. , Bandoni R. J.
Published: February 2010

Unisexual forms of certain Tremella species produce extracellular acidic heteropolysaccharides when grown on media containing glucose. The isolated polysaccharides contain the same components found in polymers produced by strains of Cryptococcus laurentii, i.e., D-glucuronic acid, D-xylose, D-mannose, and O-acetyl. Optical rotations and molar ratios of components were determined. The polysaccharides are characteristic of the various species of Tremella which produce them. Some of these species produce polymers that contain much higher proportions of xylose than are found in the polymers produced by C. laurentii. Those tremellae that produce polymers resembling C. laurentii polysaccharides also give similar carbon assimilation patterns, but tremellae that produce polymers of higher xylose content also assimilate fewer carbon compounds. These findings, together with similarities in starch synthesis and morphology, suggest a relationship between some species of Tremella and Cryptococcus.
BIOSYNTHESIS OF BRANCHED-CHAIN FATTY ACIDS: IV. FACTORS AFFECTING RELATIVE ABUNDANCE OF FATTY ACIDS PRODUCED BY BACILLUS SUBTILIS
Authors: Kaneda Toshi
Published: February 2010

The fatty acids produced by Bacillus subtilis may be grouped into four pairs: 12-methyltetradecanoic and 14-methylhexadecanoic acids (anteiso-C15and anteiso-C17), 13-methyltetradecanoic and 15-methylhexadecanoic acids (iso-C15and iso-C17), 12-methyltridecanoic and 14-methylpentadecanoic acids (iso-C14and iso-C16), and myristic and palmitic acids (n-C14and n-C16). Any one of the branched-chain amino acids, L-isoleucine, L-leucine, or L-valine, or of the branched short-chain fatty acids, α-methylbutyrate, isovalerate, or isobutyrate, added to the glucose – yeast extract medium increased the synthesis of the specific pairs of fatty acids structurally related to the added substrate and decreased the synthesis of other fatty acids. This indicates that the relative abundance of branched-chain fatty acids in B. subtilis is a function of the relative availability of the precursors of the terminal portions of the fatty acids, presumably α-methylbutyryl-CoA, isovaleryl-CoA, and isobutyryl-CoA. This mechanism is consistent with the relative abundances of branched-chain fatty acids found in mutants of B. subtilis which require particular branched-chain amino acids. The biotin content of the culture medium and the length of incubation time also affected the relative abundance of the fatty acids.
THE EFFECT OF HYPERBARIC OXYGEN UPON AEROBIC BACTERIA: I. IN VITRO STUDIES
Authors: Wiseman Gordon M. , Violago Francisco C. , Roberts Elgin , Penn Israel
Published: February 2010

The effect of hyperbaric oxygen, at pressures ranging from 1 to 4 atm absolute, upon the growth of a variety of pathogenic and commensal bacteria, was studied. Marked differences in the effect of oxygen were observed between organisms grown on solid and in liquid media. The effect of oxygen also varied markedly with the species of microorganism and with the tension of oxygen. No synergistic effect between hyperbaric oxygen and several antibiotics could be found.
RHIZOSPHERE EFFECT OF HEALTHY AND DISEASED LODGEPOLE PINE SEEDLINGS
Authors: Timonin M. I.
Published: February 2010

Comparative studies of the rhizosphere of healthy and diseased lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) seedlings revealed a definite rhizosphere effect. Higher counts of bacteria and fungi were found in the rhizosphere of diseased seedlings whereas the incidence of sporeforming bacteria antagonistic to Fusarium culmorum (W.G. Sm.) Sacc. and Rhizoctonia solani Kühn was nearly six times greater in the rhizosphere of healthy seedlings than in that of diseased seedlings. Species of Aspergillus, Phoma, Pythium, Rhizoctonia, and Rhizopus were isolated only from the rhizosphere of diseased seedlings; Alternaria, Cephalosporium, Metarrhizium, Spicaria, and Tilachlidium were isolated only from the rhizosphere of healthy seedlings. Aspergillus restrictus, A. fumigatus, Cylindrocarpon olidum, and Botryosporium sp. proved to be pathogenic to lodgepole pine seedlings. These results are discussed in relation to the microbial population in the rhizosphere of a variety of cultivated plants resistant and susceptible to soil-borne pathogens.
INFLUENCE OF CLAY MINERALS ON MICROORGANISMS: I. MONTMORILLONITE AND KAOLINITE ON BACTERIA
Authors: Stotzky G. , Rem L. T.
Published: February 2010

Respiration of bacteria was stimulated most by montmorillonite, primarily as the result of this clay maintaining the pH at levels adequate for sustained growth; additional mechanisms also appeared to be involved. Kaolinite and montmorillonite served equally as a source of minerals for bacterial nutrition, and the stimulation by montmorillonite above that elicited by kaolinite and attributable to its buffering capacity was, therefore, not related to its ability to supply inorganic nutrients. Montmorillonite stimulated respiration of a wide spectrum of bacterial species differing in morphology, motility, Gram reaction, etc. at all stages of their development, but especially by shortening the lag phase. These results suggest a possible relationship between clay minerals and activity, ecology, and population dynamics of microorganisms in natural habitats.
GROWTH OF ARTHROBACTER CITREUS AT AN ELEVATED TEMPERATURE: I. PROMOTION BY ASSOCIATED MICROORGANISMS
Authors: Chan E. C. S. , Johnson M. B.
Published: February 2010

The arthrobacters are generally regarded as showing little or no growth at 37 °C. It was found that Arthrobacter globiformis grew at 25, 30, and 37 °C on nutrient agar and trypticase soy agar; A. citreus grew on nutrient agar at 25 but not at 30 and 37 °C. On trypticase soy agar A. citreus grew well at all three temperatures. On nutrient agar, A. citreus grew at temperatures of 30 and 37 °C in the presence of any one of a number of different associated microorganisms, which included bacteria, yeasts, molds, and actinomycetes.
USE OF KANAMYCIN FOR THE ISOLATION OF AUXOTROPHIC MUTANTS OF ACTINOBACILLUS MALLEI
Authors: Evans D. H.
Published: February 2010

Growth of Actinobacillus mallei was inhibited by kanamycin; the minimal inhibitory concentration in a complex medium was 1.25 μg/ml and in a chemically defined medium 5 μg/ml. Higher concentrations of kanamycin had a pronounced bactericidal effect. When a suspension of cells containing 5 × 107 viable cells/ml was incubated in the presence of 20 μg/ml of kanamycin in a chemically defined medium, complete sterilization resulted after 6 hours. Cells irradiated with ultraviolet light were grown in complex or supplemental minimal media, washed, and exposed to 20 μg/ml of kanamycin in minimal medium for 4 hours. Auxotrophic mutants with requirements for tryptophane, phenylalanine, proline, and uracil were detected among the survivors of kanamycin treatment. After treatment with 0.01 M nitrous acid and growth in minimal medium supplemented with amino acids, cells were washed and then exposed to kanamycin in minimal medium. The proportion of autotrophs among the survivors varied from 1.3 to 75%. Mutants with requirements for each of the following amino acids were identified: methionine, methionine or cystine, arginine, leucine, tryptophane, histidme, and proline, with methionine-requiring mutants predominating. Exposure of mixtures of prototrophs and uracil-dependent and methionine-dependent auxotrophs to 20 μg/ml of kanamycin for 4 hours resulted in approximately 700- and 300-fold increases, respectively, in the ratio of auxotrophs to prototrophs.
GROWTH OF ARTHROBACTER CITREUS AT AN ELEVATED TEMPERATURE: II. PROMOTION BY METALLIC IONS
Authors: Wong P. T. S. , Chan E. C. S. , Page O. T.
Published: February 2010

Studies were undertaken to elucidate factors which promote growth of Arthrobacter citrem on nutrient agar at 37 °C. It was shown that nutrient agar was not actively inhibitory to A. citreus at this temperature. In nutrient medium, neither yeast extract, Casamino acids, nor fermentable sugars promoted growth at 37 °C. However, the ash of trypticase soy broth when added to nutrient broth supported growth at 37 °C. Na+and K+were found to have a similar growth-promoting effect. Mg++, Ca++, and Fe+++had no activity while Mn++was inhibitory. Buffered cell-suspensions of A. citreus showed a higher rate of leakage of ultraviolet-absorbing (260 mμ) materials at 37 than at 25°C. It appears that cell lysis and release of intracellular materials occur at 37 °C. Data from paper chromatographic and tracer techniques suggested that these released substances are nucleotides.
ACRIDINE ORANGE FLUOROCHROMING AND ULTRAVIOLET ABSORPTION OF STAPHYLOCOCCUS AUREUS CELLS MODIFIED BY UNBALANCED NUCLEIC ACID AND CELL WALL SYNTHESIS
Authors: Repentigny Jacques de , Sonea Sorin , Frappier Armand
Published: February 2010

Cultures of Staphylococcus aureus were grown in the presence of five different antimetabolites (5-fluorodeoxyuridine, aminopterin, 8-azaguanine, mitomycm-C, 5-fluorouracil) active against ceil walls and (or) nucleic acids. Fluorescence microscopy of smears stained with acridine orange revealed reddish and green cells in both treated and untreated cultures. There were less than 20% of reddish cells in untreated cultures and more than 40% in treated cultures. Treated cultures contained fewer viable organisms. All antimetabolites except mitomycin-C produced a diminution in the nucleic acids, chemically determined as percentage of dry weight of bacteria. Only 5-fluorouracil increased the RNA/DNA ratio. However, with ultraviolet microscopy at 260 mμ wavelength the absorption of reddish cells is much higher than that of the green cells, which, at the cellular level, seemed to indicate a greater nucleic acid content. With ultraviolet or with fluorescence microscopy we have obtained similar evidence of the cellular heterogeneity produced by antimetabolites in bacterial populations.
FACTORS AFFECTING THE GROWTH OF MYCOBACTERIUM MARINUM
Authors: Trentham Barbara Newton , McVeigh Ilda
Published: February 2010

The two strains of Mycobacterium marinum Aronson (Mycobacterium balnei Nordén) investigated were able to grow in a CO2-enriched atmosphere (5 and 10% CO2) in media in which they failed to grow or grew poorly when incubated in air. One strain grew better at 37 °C in cultures incubated in a CO2-enriched atmosphere than it did in cultures incubated at 30 °C either in air or in the CO2-enriched atmosphere. The growth of the second strain was stimulated markedly by CO2during incubation at 30 °C, and it was able to grow at 37 °C when supplied with additional CO2, although not as well as at 30 °C. Glutamic acid was the best single source of nitrogen for the growth of each strain, but one strain grew almost as well with asparagine. Oleic acid exerted inhibitory effects on the growth of each strain in a synthetic medium at 37 °C, whereas it produced a slight stimulatory effect on their growth at 30 °C. Tween 80 inhibited the growth of each strain in the synthetic medium at both 30 and 37 °C, but the degree of inhibition was greater at the higher temperature. Methods for obtaining uniform suspensions of the cells are described.
A STUDY OF ARYLSULFATASE ACTIVITY IN PROTEUS RETTGERI
Authors: Milazzo F. H. , Fitzgerald J. W.
Published: February 2010

Arylsulfatase was detected in a strain of Froteus rettgeri using two substrates, nitrocatechol sulfate (NCS) and nitrophenyl sulfate (NTS). Activity was found when the organism was grown in a chemically defined medium with methionine as the only added source of sulfur. No activity was demonstrated when sulfate was substituted for methionine in the growth medium.Maximum hydrolysis of NCS occurred at pH 6.7 in 0.15 M phosphate buffer at 37 °C and maximum hydrolysis of NPS at pH 8.3 in 0.75 M Tris–acetate buffer at 34.5 °C.Sodium cyanide (10−2 M) inhibited hydrolysis of both substrates and sodium sulfate (10−2 M) inhibited hydrolysis of NCS but not NPS. With sodium dihydrogen phosphate (10−2 M) there was increased hydrolysis of NCS and inhibition of NPS hydrolysis.The sulfatase activity in P. rettgeri is compared with that reported in other bacterial systems.
BACTERIAL METABOLISM OFD-ASPARTATE INVOLVING RACEMIZATION AND DECARBOXYLATION
Authors: Markovetz A. J. , Cook W. J. , Larson A. D.
Published: February 2010

A pseudomonad was isolated from soil with D-aspartate serving as sole carbon source. Whole cells and cellular extracts produced carbon dioxide and DL-alanine from D- and L-aspartate. The addition of oxamycin to cellular extracts inhibited the alanine racemase found to be present and it was ascertained that L-alanine was formed from both D- and L-aspartate, indicating that D-aspartate had been racemized to the L-isomer with subsequent decarboxylation to L-alanine.
ESTIMATION OF VIRULENCE OF STAPHYLOCOCCUS AUREUS FOR MICE: THE EXCEPTIONAL VIRULENCE OF THE SMITH STRAIN
Authors: Parker Shirley E. , Warner Peter , Slipetz Willy Kole
Published: February 2010

A precise method of assaying virulence of Staphylococcus aureus for mice by intraperitoneal injection with mucin is described; the results indicated that most bacteriophage types of S. aureus possessed similar virulence, an LD50 consisting of millions of organisms. The variability in results of similar tests by previous authors is thought to reside in the use of techniques allowing excessive variability.The Smith strain of S. aureus is shown to be exceptionally virulent, requiring only one colony-forming unit to kill a mouse. However, the survival time of mice after inoculation with the Smith strain is longer than that of other strains giving equivalent mortality. An explanation is suggested for this latter phenomenon, and the manner in which the Smith strain causes death is considered.
DESCRIPTION OF A BACTERIUM ASSOCIATED WITH REDMOUTH DISEASE OF RAINBOW TROUT (SALMO GAIRDNERI)
Authors: Ross A. J. , Rucker R. R. , Ewing W. H.
Published: February 2010

A description was given of a gram-negative, peritrichously flagellated, fermentative bacterium that was isolated on numerous occasions from kidney tissues of rainbow trout (Salmo gairdneri) afflicted with redmouth disease. Although the bacteria apparently were members of the family Enterobacteriaceae, it was impossible to determine their taxonomic position within the family with certainty. Hence it was recommended that their taxonomic position remain sub judice for the present. As a temporary designation RM bacterium was used.Redmouth disease was transmitted from infected to normal fish through the medium of water.
PRODUCTION OF PYOGYANINE BY PSEUDOMONAS AERUGINOSA ATCC 9027
Authors: MacDonald J. C.
Published: February 2010

The ability of various synthetic media to support pyocyanine production by Pseudomonas aeruginosa ATCC 9027 and PRL F20 was assessed in both stationary and shaken cultures. Media which gave good pyocyanine yields with stationary cultures did not necessarily do so with shaken cultures. The production of pyocyanine by ATCC 9027 grown in shaken cultures on media containing 0.04% K2HPO4 was low, and was increased by lowering the concentration of phosphate.