bluuebunny/crossref_metadata_2025 huggingface dataset:
Characteristics of Erwinia amylovora bacteriophage and its possible role in the epidemiology of fire blight
Authors: Erskine J. M.
Published: February 2010

Bacteriophage (S1) of Erwinia amylovora, isolated from soil at the base of fire-blight-infected trees, was characterized by small, clear plaques on E. amylovora strain PR1 and hazy plaques of the same size on a closely related, yellow, saprophytic bacterium, Y, which was isolated together with PR1 from the diseased trees. Phage S1 plated with optimal efficiency at 10C on PR1 and at 28C on Y was relatively unstable to storage at temperatures typical of summer and to ultraviolet (UV) irradiation, and lysogenized Y but not PR1. Pathogenicity tests in pear slices demonstrated that symptom development was (i) delayed when mixtures of either PR1 and phage S1 or PR1 and Y were inoculated, (ii) delayed when a culture of a phage-resistant mutant of PR1 was inoculated, and (iii) prevented from appearing at all when PR1 and the lysogenic form of Y, Y (S1), were inoculated together. Strain Y was easily lysogenized and Y (S1) released phage spontaneously and after UV irradiation. It is suggested that the yellow saprophyte, which is invariably isolated from fruit trees with E. amylovora, may frequently occur in its lysogenic form in nature and serve as a reservoir of phage which may exert some influence on the occurrence and severity of fire-blight disease.
Methionine biosynthesis and S-adenosylmethionine degradation during an induced morphogenesis of Candida albicans
Authors: Balish Edward
Published: February 2010

Seven strains of Candida albicans were used in studies designed to delineate altered biochemical activity during an induced yeast to filamentous morphogenesis. Four of the strains studied underwent a rapid (1–2 h) yeast to filamentous transformation in a defined medium with glycine as the main nitrogen source; three other strains of C. albicans remained yeast-like under the same growth conditions. Cell-free extracts, prepared from cells harvested after various time intervals of growth in glycine medium, were used to measure enzymic capacity to form methionine, via the enzyme S-adenosylmethionine (or methylmethionine) homocysteine methyltransferase, and degrade S-adenosylmethionine. Increased enzymic capacity to synthesize methionine (with S-adenosylmethionine as methyl donor) and degrade S-adenosylmethionine appeared to correlate best with a yeast to filamentous transformation of C. albicans. Intracellular S-adenosylmethionine content also decreased with time, in all seven strains, when the cells were cultured in the glycine medium. S-adenosylmethionine may play a key role in the biochemical alterations that occur during the morphogenesis of C. albicans.
The temperature-dependent effect of residual nematicides on the activities of soil microorganisms
Authors: Tu C. M.
Published: February 2010

The effects of Dasanit®, carbofuran, D–D®, and Vorlex® on microbial activities in a loamy sand were evaluated in laboratory experiments at temperatures of 5 and 28C. Bacterial and fungal populations initially decreased with some of the fumigant treatments but the populations recovered after 2 weeks. D–D and Vorlex significantly stimulated ammonification of soil native organic nitrogen at 28C after 4 weeks. In some instances, fumigants decreased ammonium production from added peptone at low temperature. No inhibition of nitrification and sulfur oxidation was evident with any of the nematicides. The effect of fumigant and glucose treatments on the respiration of microorganisms at 15 and 30C showed that the inhibition period observed in the early stages of incubation was negatively correlated with the soil temperature.
A Flavobacterium sp. that degrades diazinon and parathion
Authors: Sethunathan N. , Yoshida T.
Published: February 2010

A Flavobacterium sp., isolated from paddy water by enrichment culture technique, decomposed diazinon in a mineral medium as sole carbon source. The bacterium readily hydrolyzed diazinon to 2-isopropyl-6-methyl-4-hydroxy-pyrimidine which was then converted to carbon dioxide. The bacterium also converted parathion to p-nitrophenol. The enzyme involved in the hydrolysis was constitutive.
Association of virulence characteristics of Erwinia amylovora with toxigenicity of its phage lysates to rabbit
Authors: Erskine J. M.
Published: February 2010

A highly virulent strain of Erwinia amylovora when lysed by its bacteriophage released a substance which was toxic for rabbits. A weakly virulent strain of the phytopathogen yielded less toxin. A lysate prepared with the same phage from an avirulent amylovora-like bacterium was non-toxic.
Cultural characterization and differentiation of nocardiae
Authors: Kwapinski J. B. G. , Horsman G.
Published: February 2010

Cultural and colonial morphology of 120 strains of nocardiae had been determined in three different semisynthetic media. On the basis of ability or inability to grow in the most reduced medium, and of growth pattern observed in the other liquid media, the nocardiae were categorized in six cultural groups. The reproducible and clear-cut cultural properties are considered a useful criterion for species differentiation.
Control of tartrate utilization in Aspergillus flavus
Authors: Mahnensmith Rex L. , Long Deborah , Detrick Ruthanne , Klatt K. P.
Published: February 2010

The utilization of L(+)-tartrate in Aspergillus flavus is constitutive. The use of tartrate by these cells is inhibited by the metabolic poisons 2,4-dinitrophenol and sodium azide. Glucose, mannose, and sucrose at high extracellular concentrations prevent the utilization of L(+)-tartrate by the young mycelium. Ammonium ion increases the inhibition due to glucose, while the addition of ferric ions to the external medium prevents the glucose-induced inhibition of tartrate utilization.
Corynebacterium cyclohexanicum n. sp.: a cyclohexanecarboxylic acid utilizing bacterium
Authors: Tokuyama Tai , Kaneda Toshi
Published: February 2010

A cyclohexanecarboxylic acid utilizing bacterium, strain MU, has been isolated from soil and its taxonomic and physiological nature studied. The organism requires biotin or an unidentified factor present in yeast extract for growth, and can use one of various acids, alcohols, and carbohydrates as the sole carbon source.As the organism is a non-motile rod, gram-positive, non-sporing, not acid-fast, catalase-positive, and aerobic, it is identified as a Corynebacterium. Various growth and biochemical characteristics show that the organism is closely related to Corynebacterium equi but differs in several characteristics. Hence, a separate species, Corynebacterium cyclohexanicum is proposed for strain MU because of its unique use of cyclohexanecarboxylic acid. Results from manometric experiments indicate that its metabolism of cyclohexanecarboxylic acid is closely related to the well-established metabolic scheme of benzoic acid.
Self-inhibition of arthrospore germination in Geotrichum candidum
Authors: Steele S. D.
Published: February 2010

An attempt to isolate a self-inhibitor of spore germination in Geotrichum candidum Link was unsuccessful because of the instability of the self-inhibitor. The ability of different carbon sources to stimulate germination and support somatic growth was tested in self-inhibitory conditions. Acetate, fructose, galactose, and glycerol supported both germination and somatic growth. All the fatty acids tested allowed germination but were unable to support vegetative growth; conversely mannitol could not induce germination but did support vegetative growth. Measurements of oxygen uptake by germinating arthrospores at various arthrospore concentrations showed a decrease in oxygen uptake per spore as the spore concentration (= self-inhibitor concentration) increased. Oxygen uptake per spore by dormant arthrospores also decreased with increasing spore concentration. Spore age was another factor influencing oxygen uptake by dormant spores; oxygen uptake per spore decreased with increasing spore age up to 7 days. Continued aging did not decrease the rate of oxygen uptake any further.
Biosynthesis of thiamine by Phycomyces blakesleeanus
Authors: Houston M. R. , McVeigh Ilda
Published: February 2010

Phycomyces blakesleeanus was grown in a minimal glucose–asparagine broth medium supplemented with either 2-methyl-4-amino-5-hydroxymethylpyrimidine-4,7-14C or 4-methyl-5-(2-hydroxyethyl)-thiazole-2-14C and the corresponding non-labeled moiety of thiamine. Extracts of mycelia and of culture filtrates were tested for the presence of intermediates formed in the biosynthesis of thiamine by P. blakesleeanus. By combinations of ion-exchange and thin-layer chromatography, autoradiography, and bioautography, the following compounds were identified: 4-methyl-5-(2-phosphorylethyl)thiazole, 2-methyl-4-amino-5-phosphorylmethylpyrimidine, 2-methyl-4-amino-5-pyrophosphorylmethylpyrimidine, and thiamine monophosphate.
Chemical characteristics and classification of nocardiae
Authors: Lechevalier Mary P. , Lechevalier H. , Horan Ann C.
Published: February 2010

A simple gas-chromatographic method was devised for the detection of mycolic acids present in strains of Actinomycetales with a type IV cell wall (meso-DAP, arabinose, and galactose). Results obtained in the study of 89 such strains has permitted the authors to assign them to either the genus Mycobacterium (strains containing true mycolic acids) or to the genus Nocardia (strains containing nocardomycolic acids).Strains of "Nocardia farcinica" were found to belong to the genus Mycobacterium and thus the name of this species should be considered a nomen dubium. Strains of "Mycobacterium rhodochrous," "M. brevicale," and "M. thamnopheos" did not contain true mycolic acids and their assignment to the genera Nocardia or Corynebacterium was considered.
Favorable effects in vitro and in vivo of two clinical isolates of Pseudomonas aeruginosa on nutritionally deficient Staphylococcus aureus strains
Authors: Gadbois T. , Repentigny J. De , Mathieu L. G.
Published: February 2010

We have studied aspects of interbacterial ecology with nutritionally dependent Staphylococcus aureus strains; they were grown in association with Pseudomonas aeruginosa in systems of mixed cultures and infections in vitro in a semisynthetic medium and in vivo in mouse peritoneal cavity and rabbit skin. In mixed cultures and in P. aeruginosa culture filtrates, thymine and tryptophan deficiencies in staphylococci were partly overcome. This is probably because P. aeruginosa supplied the essential metabolites required to ensure growth; however, other metabolic activities could also be involved. Other experiments showed that the sensitivity of thymineless staphylococci to nucleoside inhibitions was alleviated. In mixed infections with P. aeruginosa, the S. aureus thymineless strain has shown a greater ability to survive in the peritoneal cavity of mice than when injected alone, even when one species was injected after the other with different doses of bacteria. The examination of the liquid from the peritoneal cavity of infected mice by fluorescence microscopy after fluorochroming with acridine orange or auramine O has revealed that Pseudomonas endotoxin seems to damage leucocytes and consequently reduces the phagocytosis of Staphylococcus cells.Necrosis in rabbit skin was mainly due to S. aureus when both species were injected together intradermally; the thymineless strain was less harmful than the parent strain.It seems that survival and even growth of nutritionally dependent strains of a bacterial species can be favored by the metabolic activities of another species in mixed cultures and infections, in this instance S. aureus by P. aeruginosa. This phenomenon among others could be a determinant of bacterial pathogenicity for nutritionally dependent pathogenic bacteria; thus associated organisms could determine the effective pathogenicity of nutritionally dependent bacteria by contributing essential nutrilites at the site where infection is initiated.
Estimation with several culture media of spirilla of 11 natural sources
Authors: Scully Douglas A. , Dondero Norman C.
Published: February 2010

The most probable numbers (MPN) of spirilla were estimated in samples of Cladophora, pond water and mud, stream water and slime, trickling filter effluent, standing hay, field drainage, cow manure, woods soil, and cultivated field soil. Six formulations of MPN media were compared: vermiculite–albumin, nutrient gelatin agar, calcium lactate, artificial activated sludge, 5-fluorouracil, and hay infusion. Vermiculite–albumin generally gave the greatest numbers of three morphological types of spirilla. Spirilla were about 4% of the total bacterial population associated with Cladophora; about 0.1 to 0.6% of the bacteria of mud, water, slime, trickling filter effluent, and cow manure; and less than 0.01% of the remainder except hay, in which they were not found.
Isolation and morphology of native intracellular polyglucose granules from Clostridium pasteurianum
Authors: Laishley E. J. , MacAlister T. J. , Clements I. , Young C.
Published: February 2010

Intracellular polyglucose granules have been isolated from late log-phase cells of Clostridium pasteurianum. These granules are spherical in shape, heterogeneous in size, and surrounded by a membrane coat which lacks the characteristics of a typical unit membrane. Freeze-etching reveals projections of 12 to 16 nm in diameter in the matrix of the granules, which suggest the presence of polysaccharide fibrils.
Ultrastructure of bacterial spines
Authors: Easterbrook K. B. , McGregor-Shaw J. B. , McBride R. P.
Published: February 2010

A marine bacterium produces appendages (spines) which consist of rigid tubes, about 70 nm in diameter. These are expanded at the base and attached to, but not originating in, the cell wall. The wall of the spine is smooth on the inside but ridged on the outside. The ridges, which appear as striations in shadowed or negative-stained preparations, are continuous along the length of the spine and helically arranged. The fine structure of these spines is demonstrated.
Genetic homologies among nocardiae and other actinomycetes
Authors: Bradley S. G. , Brownell G. H. , Clark Josephine
Published: February 2010

The extent of association between deoxyribonucleic acid (DNA) from various actinomycetes with reference DNA samples from two strains of Nocardia erythropolis has been used as an index of relatedness. N. erythropolis, N. canicruria, and particular cultures designated as N. corallina and N. opaca constitute a genospecies, on the bases of ability to form DNA hybrid molecules and ability to participate in genetic recombination. The lack of reciprocity in the DNA reassociation assays involving selected strains of N. erythropolis indicates that the DNA from particular lineages possesses unique nucleotide sequences. The taxon Mycobacterium rhodochrous is heterogeneous and contains at least two discrete populations. The present results do not clarify the relationships of the N. erythropolis genospecies to the other nocardiae, streptomycetes, or mycobacteria. The differences in extent of hybrid DNA duplex formation at exacting and non-exacting incubation temperatures reflect the degree of matching between the compared nucleotide sequences. On this basis, actinomycete DNA samples differ from one another by nucleotide alterations dispersed throughout the genome. DNA hybridization is a sensitive assay for molecular evolution and may be able to detect neutral and nearly neutral mutations that are not recognized phenotypically.
Effet d'une souche de Lactobacillus sur la cinétique d'établissement de Shigella flexneri et d'Escherichia coli dans le tube digestif de souriceaux "Gnotoxéniques." Rôle de l'immunisation des mères
Authors: Ducluzeau R. , Raibaud P.
Published: February 2010

A strain of either Shigella flexneri, Escherichia coli, or each of these two strains with a strain of Lactobacillus is implanted in the digestive tract of different couples of axenic adult mice.Some pregnant mothers are vaccinated with the three strains before implantation. The vaccination does not change the kinetics establishment of all three bacterial strains in either the mothers or the young.Escherichia coli is established at its maximum level in "monoxenic" young mice at day 3 after birth, while Shigella appears slowly and irregularly during the 1st week of life. Both strains are established almost simultaneously in the stomach and intestine of the young mice.Lactobacillus is established at maximum level in the stomach and intestine of "dixenic" young mice at day 1 after birth. In these conditions, Shigella appears slowly, only reaching maximum level at 17 days. This antagonistic effect is especially observed in the stomach of the animals, and in a small measure, in the intestine. The establishment of E. coli is hardly affected by the presence of Lactobacillus, except in the stomach in most young animals.In no case is there interference between Lactobacillus and either one of the two strains after 3 weeks of age.
Ultrastructural changes during germination of Geotrichum candidum arthrospores
Authors: Steele S. D. , Fraser T. W.
Published: February 2010

The dormant arthrospore in Geotrichum candidum has three, possibly four, layers making up the spore wall. Nuclei, mitochondria, free ribosomes, fragments of endoplasmic reticulum, various small vacuoles, and particles of glycogen were observed within the protoplasm. During germination a new layer of wall material forms between the original spore wall and the cytoplasm. This new layer is confined to the region where germ-tube emergence occurs and is continuous with the germ-tube wall. After germ-tube emergence vesicles were seen at the apices of germlings. Another feature of germination was an apparent increase in the amount of endoplasmic reticulum, some of which appears to assume the function of the Golgi apparatus.
Specificity of cell wall labeling with tritiated diaminopimelic acid in Bacillus subtilis
Authors: Maier Siegfried
Published: February 2010

The suitability of tritiated 2,6-diaminopimelic acid (3H-DAP) as a label specific for cell walls was explored in Bacillus subtilis BC 102 grown in a medium enriched with 3H-DAP and an excess of L-lysine. Fractionation of labeled cells showed 57% of the activity in the cell wall and 28% in the membrane. Chromatography of labeled wall hydrolysates revealed two activity peaks: 62% in DAP and 29% in glutamic acid – alanine. Labeled membrane was devoid of activity in the DAP position. Chromatographic purification of the 3H-DAP improved specificity, giving 7% of the activity in the membrane and 85% in the wall. In such walls DAP accounted for 82% of the total wall activity. Therefore, only 69% of the total fixed purified 3H label remained with DAP in the wall.
Production of enniatin A
Authors: Audhya T. K. , Russell D. W.
Published: February 2010

Growth of a strain of Fusarium sambucinum in surface culture on a specially developed medium gave high yields of enniatins, from which enniatin A, free from the B and C homologues, could be obtained by column chromatography in yields of 1 g or more per liter of culture.
The effects of phospholipid depletion on the cleavage pattern of the cell walls of frozen Gram-negative bacteria
Authors: Forge A. , Costerton J. W.
Published: February 2010

Extraction of whole cells of the marine pseudomonad (B-16) with chloroform–methanol causes the disappearance of the cleavage planes, and the cross-sectioned profile of both the cytoplasmic membrane and the double-track layer of the cell wall.
Production of β-D-xylopyranosidases by fungi
Authors: Reese E. T. , Maguire Anne , Parrish F. W.
Published: February 2010

Two hundred and fifty microorganisms were tested for their ability to produce β-D-xylopyranosidase. Two of the best, Aspergillus niger and Penicillium wortmanni, were studied in greater detail for the effects of inducing compounds and of surfactants on yields. Under optimal conditions, culture filtrates were obtained which had specific activity values 10 to 60 times those of sources (sea snail, Bacillus, Chaetomium, hemicellulase) used by other investigators. In most instances, our unpurified filtrates had higher activities than did the extensively purified preparations from these other sources. The fungal β-D-xylopyranosidases hydrolyze aryl and alkyl β-D-xylopyranosides, oligomers of D-xylose, and L-serine β-D-xyloside. They do not hydrolyze β-D-xylosyl dextran, tomatin, or α-D-xylosides.
Morphology, histochemistry, and ultrastructure of mycetome and its rickettsial symbiotes in Cimex lectularius L.
Authors: Chang K. P. , Musgrave A. J.
Published: February 2010

The haematophagous bug, Cimex lectularius L., harbored in mycetomes two kinds of rickettsia-like microorganisms: morphologically, one was a small rod, the other pleomorphic, often globular. Both kinds of symbiotes had Gram-negative profiles and nuclear areas. 'Rod-shaped' symbiotes were enveloped by amorphous materials but lay freely in the mycetomes. The 'pleomorphic' symbiotes were enclosed by vacuolar membranes. Both symbiotes were lysed in cytolysomes and became masses of membranes, suggesting that this is a method of maintaining a population balance between host and symbiote.
Adenosine-induced bacteriostasis in Micrococcus sodonensis
Authors: Shobe Charles R. , Campbell J. N.
Published: February 2010

In a synthetic growth medium at a concentration of 1.0 mM, adenosine had a marked bacteriostatic effect on the growth of Micrococcus sodonensis. With the exceptions of hypoxanthine and inosine, which were slightly inhibitory, other purine bases and ribonucleosides did not inhibit the growth of the organism. When incubation of adenosine-supplemented cultures was prolonged, the organism was able to recover from the growth inhibition after a period of time which varied directly with the initial adenosine concentrations. Chromatographic analysis of the supernatants of those cultures revealed that exogenous adenosine concentrations declined steadily and the termination of the inhibited phase of growth correlated with the exhaustion of exogenous adenosine.It was observed that de novo biosynthesis of thiamine was inhibited in adenosine-supplemented cultures and that this inhibition was also relieved upon the exhaustion of exogenous adenosine. Bacteriostasis could be prevented by including either thiamine or its pyrimidine precursor (B1-pyrimidine) in adenosine-supplemented cultures and it was concluded that the observed growth inhibition reflected a depletion of the intracellular thiamine pool resulting from an adenosine-associated inhibition of B1-pyrimidine biosynthesis.
Utilisation du suc d'Helix pomatia pour le fractionnement de la paroi d'une souche sauvage et d'une souche mutante de Saccharomyces cerevisiae Hansen
Authors: Bizeau C. , Galzy P. , Baptista Elisabeth
Published: February 2010

The Helix pomatia juice has been used to dissolve in situ the cell wall of two yeast strains, a wild strain and a mutant "smooth colony" strain. The mutant strain has lost one antigenic site or more. One fraction of mannoprotein has been very less important in the mutant strain.
Lymphocyte transformation and serum agar gel diffusion of rabbits immunized against Neisseria gonorrhoeae and Neisseria catarrhalis
Authors: Esquenazi Violet , Streitfeld Murray M.
Published: February 2010

Gonococci were found to possess a number of antigens capable of stimulating lymphocyte blastogenesis in immunized rabbits. Cross antigenicity existed with N. catarrhalis; lymphocyte cross-reactivity to certain of the gonococcal soluble fractions and to whole sonicates of catarrhalis organisms followed immunization with either species. With increased postimmunization time, cross-reactions tended to disappear. Immunoprecipitate studies of the sera of immunized animals also demonstrated the cross-reactivity of the two organisms; however, only two of the gonococcal-soluble antigen fractions were reactive in this system.
Depletion of glycogen and adenosine triphosphate as major factors in the death of lobsters (Homarus americanus) infected with Gaffkya homari
Authors: Stewart James E. , Arie B.
Published: February 2010

Development of high numbers of Gaffkya homari, the pathogen causing gaffkemia in lobsters, occurs first in the hepatopancreas, followed immediately by development in the heart, and considerably later in the hemolymph. Significantly lower bacterial numbers develop in the muscle only after an appreciable lag period. Glycogen declines drastically in the tail muscle, heart, and hepatopancreas reaching nominal levels in the hepatopancreas by the 9th day of about a 2-week overall infection period recorded at 15C.A slight reduction of tail muscle ATP and about a 50% reduction in heart ATP were observed over the course of the infection; non-bacterial ATP in the hepatopancreas was virtually absent from the 9th day of the infection onward. The main conclusion based upon the foregoing suggests death was the result of hepatopancreatic dysfunction caused by G. homari disrupting or bringing to a halt the central metabolic processes of the lobsters. Trials to determine whether a bacterial toxin was produced in vivo and had acted as a contributory factor in the deaths were uniformly negative.
Analysis of cell division in rapidly growing synchronous cultures of Escherichia coli recovering from an inhibition of deoxyribonucleic acid synthesis
Authors: Khachatourians George G. , McGrath Lorraine M.
Published: February 2010

Kinetics of cell division in cultures of Escherichia coli grown in casamino acids – glucose and recovering from short pulses of inhibition of DNA synthesis by nalidixic acid clearly demonstrates that preexisting cycles of chromosome replication continue to their ends.
Microscopie photonique des nodules racinaires axéniques d'Alnus crispa var. mollis
Authors: Lalonde Maurice , Fortin J. André
Published: February 2010

With the object of knowing the endophyte morphology, axenic root nodules of Alnus crispa var. mollis Fern. were studied by light microscopy. The nodule endophyte was present in three forms: the hypha, which was branched or unbranched, measured between 0.3 μ and 1.0 μ; the vesicle (3–5 μ), which was septate, developed at the hyphal tip; and the bacteria-like cells (0.5–1.5 μ), which did not undergo digestion by the host cells. The structure of the axenic nodule was comparable to that of the natural nodule.
Induction and reversion of the L-form of Neisseria gonorrhoeae
Authors: Lawson John W. , Douglas James T.
Published: February 2010

Massive induction of Neisseria gonorrhoeae to the L-form was achieved on L-media consisting of brain heart infusion broth, 1% agar, 10% horse serum, and 100 units per milliliter penicillin. This medium was supplemented with polyvinylpyrrolidone (PVP) for stabilization. Frequencies greater than 10% were routinely found with all 11 strains tested. Five of the 11 strains were also transformed to the L-form on L-media supplemented with 10% sucrose but at efficiencies much lower than on PVP L-media. Rare L-colonies (less than 1 in 107 gonococci) of these same five strains were also isolated on unstabilized L-media. No L-forms were ever isolated from the remaining six strains on sucrose or on unstabilized L-media. The penicillin concentration in the media, if above a lethal amount, had little effect on the efficiency of L-phase induction on PVP L-media but was critical for isolation on sucrose L-media. Colonial growth of the L-form was much more rapid and luxuriant on PVP than on sucrose L-media. In addition, subculture by the agar-block technique of L-phase colonies induced on PVP L-media routinely occurred while growth was seldom obtained on subculture from sucrose L-media. Reversion to the gonococcal parent occurred (1) on transfer of growth by the agar-block technique to similar media without penicillin or to Mueller Hinton blood agar, (2) in L-broth into which an agar block containing L-colonies was placed and time allowed for decay of penicillin, (3) on sucrose but not PVP L-media, within the original transformed L-colonies after penicillin decay. Growth in PVP L-broth was achieved. On transfer from broth culture to growth media without penicillin, reversion to the parental gonococci occurred.
Effect of oxygen-transfer rate on production of L-asparaginase by Erwinia aroideae
Authors: Liu F. S. , Zajic J. E.
Published: February 2010

A variety of aeration and agitation conditions were used to investigate the oxygen demand of Erwinia aroideae for growth and L-asparaginase production in a 14-liter fermenter. Maximum L-asparaginase activity of 4.25 IU/ml was obtained when the fermentation medium was aerated at 0.5 volumes air per volume medium per minute and agitated at 500 rpm. However, the specific L-asparaginase activity was not affected significantly by the rate of oxygen transfer. In most instances the level of dissolved oxygen decreased to zero before harvesting. KLa rather than dissolved oxygen as measured during the fermentation cycle is a more satisfactory index to determine the oxygen requirement for cell growth and asparaginase production. The optimum level of KLa for L-asparaginase production was 0.98 min−1. However, a higher value of KLa of 1.2–1.9 min−1 was needed to achieve the highest growth.
The effect of cationic compounds of biological origin on the heat resistance of Bacillus subtilis spores
Authors: Ottaviano Paul J. , Kinsley Jr. Richard N. , Gaby William
Published: February 2010

Spores of Bacillus subtilis were produced in the presence of several cationic compounds. Thermal-destruction studies revealed that cationic compounds increased heat resistance of the spores. Of the compounds tested, lysine-rich histone, isolated from calf thymus, afforded the greatest degree of protection against moist heat at 100°.
Benomyl, PCNB, and sodium selenate as agents to protect fungal cultures from Penicillium and other contaminants
Authors: Vaartaja O.
Published: February 2010

Selective media were formulated for the pure culturing of a variety of fungi under heavy contamination risk. Growth of 50 species, including five common contaminants, was observed on seven media. Certain media greatly facilitated work with cultures of many slow-growing basidiomycetes in Petri dishes that were frequently opened and exposed to heavy contamination by Penicillium spp. Benomyl at 0.4 ppm or higher was used to inhibit Penicillium spp. and Monilia sitophila. Sodium selenate at 100 ppm was also used to inhibit Penicillium spp. Pentachloronitrobenzene at 10 to 25 ppm, in various combinations with benomyl and sodium selenate, was used to inhibit Penicillium spp., M. sitophila, Paecilomyces sp., Rhizopus nigricans, and Acremonium roseum. Three antibiotics, including bacitracin at 50 ppm, were used to inhibit bacteria.
Malic enzyme of Fusarium oxysporum
Authors: Zink M. W. , Katz J. S.
Published: February 2010

The levels of the NADP-specific malic enzyme in Fusarium oxysporum are controlled by both the carbon and nitrogen sources in which the cells are grown. The enzyme is not induced by malate; maximum activity is obtained when the mycelium is grown on sucrose or ethanol. With ammonium sulfate as the nitrogen source, one enzyme-activity peak is obtained by 40 h, while in the presence of potassium nitrate this peak is repressed, with a peak appearing at a later stage of growth. In ammonium nitrate, two enzyme-activity peaks are present, one corresponding to the peak present in ammonium sulfate and the other to the peak present in potassium nitrate grown cells.When the initial velocities are plotted against increasing malate concentration non-Michaelis–Menton kinetics are obtained. The double-reciprocal plots are biphasic and Rs values of 161 are obtained. Hill plots prepared from initial velocity data show that at low malate concentration, the slope of the line is 0.87, and it decreases to 0.45 at 1.32 × 10−3 M malate. With increasing malate concentration the slope increased to a value of 1.0. It appears that this type of kinetic behavior is typical of a system in which there is negative cooperativity with respect to ligand binding with concurrent progressive substrate activation.
Growth and enterotoxin B synthesis by Staphylococcus aureus S6 in associative growth with Pseudomonas aeruginosa
Authors: Collins-Thompson D. L. , Aris B. , Hurst A.
Published: February 2010

The interaction of Pseudomonas aeruginosa and Staphylococcus aureus S6 was studied in two systems. In the first system, the two organisms were grown together in a single flask. Growth of P. aeruginosa was unaffected, but growth of S. aureus was modified. After 24 h, 99.9% of the staphylococci population lost their salt tolerance when plated on media containing 7.5% sodium chloride, and enterotoxin B synthesis by S. aureus was diminished. In the second growth system, pure cultures of P. aeruginosa and S. aureus were grown in membrane-type spinner flasks. The growth and salt tolerance of S. aureus was again affected, but to a lesser degree. Cultures of S. aureus from these experiments recovered their salt tolerance in 6 h when transferred to fresh medium.Nutrient deficiency, lack of oxygen, or pigment production by the pseudomonads did not contribute significantly to loss of salt tolerance or inhibition of enterotoxin B synthesis, but a staphylolytic enzyme(s) isolated from P. aeruginosa was shown to be responsible for the loss of these properties.
Lipopolysaccharide and proteins of the cell envelope of Vibrio marinus, a marine bacterium
Authors: Deneke Carl F. , Colwell R. R.
Published: February 2010

Lipopolysaccharides isolated from the marine bacterium Vibrio marinus strain PS-207 were found to be similar to the lipopolysaccharides of R mutants of enteric organisms, with respect to extraction characteristics, percentage of lipid A (61%), and sugars of the polysaccharide side chain (glucose and heptose). A high ratio (2:1) of phosphate to amino sugar was found in the lipid A. Hydroxy fatty acids constituted only 14% of the total fatty acids of the lipid A fraction, whereas branched and straight-chain fatty acids were present in greater abundance. The major envelope proteins of V. marinus strain PS-207 fell into three molecular weight classes determined by SDS gel electrophoresis. Numerous protein species were observed in urea – acetic polyacrylamide gel electrophoresis preparations.
Influence of inorganic nitrate on the formation of extracellular protease and ribonuclease by Penicillium janthinellum
Authors: Ghosh R. K. , Thangamani A.
Published: February 2010

The influence of nitrogen source on the formation of the extracellular acid protease and acid ribonuclease in shake cultures of the mold Penicillium janthinellum has been studied. It is observed that there is a long delay in the formation of the enzymes when nitrate is the sole source of nitrogen, but they are formed much earlier on other nitrogen sources such as ammonium salts, urea, or bacto-peptone. They are also formed earlier when nitrate is partially replaced by an ammonium salt. Small amounts of nitrite and hydroxylamine inhibit the formation of the enzymes when the mold is grown on ammonium lactate. When the mold is grown on nitrate, the culture filtrates contain inhibitory amounts of nitrite and hydroxylamine. The results indicate that the delayed formation of the enzymes in nitrate medium may be due to the formation of nitrite and hydroxylamine, which are inhibitory. The activities of the two enzymes are not inhibited by nitrite or hydroxylamine, in vitro. Prolonged preincubation of the enzymes with nitrite or hydroxylamine also does not affect the enzyme activities, indicating that it is the formation of the enzymes that is affected.
Occurrence of P503 in microorganisms
Authors: Kropinski Andrew M. B. , Boon Joyce , Poulson Rozanne , Polglase W. James
Published: February 2010

A pigment absorbing at 503 nm (P503) was observed in the difference spectra of several strains of microorganisms. The pigment was present in most facultative anaerobes and absent from many but not all of the aerobes examined. P503 is probably not a component of the normal oxygen-linked electron transport chain since the pigment was present in both respiratory sufficient (ρ+) and deficient (ρ−) strains of Saccharomyces cerevisiae. There was no apparent correlation between P503 and either the cytochromes or any known metabolic cellular activities. However, the widespread occurrence of P503 in microorganisms suggests that it is of functional significance.
Properties of P503 in Escherichia coli
Authors: Kamitakahara-Pearlstone Joyce , Poulson Rozanne , Polglase W. J.
Published: February 2010

The pigment (believed to be a tetrahydroporphyin) which appears, transiently, at 503 nm (P503) in the difference spectrum of intact cells of Escherichia coli B did not accumulate in cultures grown in medium supplemented with L-methionine. Accumulation of P503 was not prevented by structural analogues of L-methionine, nor by a mixture of natural amino acids excluding L-methionine. A methionine-requiring mutant of E. coli K-12 lacked P503 when grown in the presence of L-methionine, but P503 was present if D,L-ethionine was substituted for L-methionine in the growth medium. When L-methionine was added to air-oxidized cells which had been grown on minimal (glucose–salts) medium, the spectrum of P503 was produced specifically and rapidly. This effect of L-methionine in non-proliferating cells together with the inhibition by L-methionine of P503 accumulation in growing cultures may result from the stimulation of coproporphyrinogenase by methionine. The data indicate that P503 is an early intermediate in the conversion of coproporphyrinogen III to protoporphyrin IX rather than an intermediate in the porphyrin synthesis "by-pass' to coproporphyrin III.
CO2 fixation and metabolic control in Pseudomonas saccharophila
Authors: Donawa A. L. , Ishaque M. , Aleem M. I. H.
Published: February 2010

Hydrogen-dependent CO2-fixation experiments indicated the formation of several products including alanine, aspartate, phosphoglycerate, glutamate, and phosphorylated sugars by Pseudomonas saccharophila. The enzymes that are involved in the fixation are carboxydismutase, phosphoenolpyruvate carboxylase, and the malic enzyme. Ribulose diphosphate carboxylase, ribulose 5-phosphokinase, and ribose 5-phosphoisomerase show decreased activity whereas most of the tricarboxylic acid cycle enzymes and NADH oxidase show increased activity in heterotrophically grown cells. The glyoxylate pathway and permeases specific for the tricarboxylic acid cycle intermediates also vary in levels of activity according to the mode of growth. Although the oxygen tension appears to have an effect on enzyme levels during growth, the carbon source seems to be more important.
Effect of time and temperature on ochratoxin A production by Aspergillus ochraceus
Authors: Sansing Gerald A. , Davis Norman D. , Diener Urban L.
Published: February 2010

Peak ochratoxin A production by Aspergillus ochraceus occurred at 25C after 10 and 12 days incubation on a nutrient solution of 4% sucrose and 2% yeast extract. Optimal mycelial production was at 20 and 25C at 6, 8, and 10 days incubation. High pH values of 7.6–8.2 coincided with high ochratoxin production at 25C at 8-14 days incubation. Maximal amounts of ochratoxin A were produced by A. ochraceus in 25 ml of medium/125-ml flask and 75 ml of medium/500-ml flask at 25C in stationary culture in 8 days. Ochratoxin A was not produced in this medium in shake culture.
Disk-plate method for selective isolation of Rhizoctonia solani from soil
Authors: Herr L. J.
Published: February 2010

A disk-plate method was devised for isolation of Rhizoctonia solani from soil in the field. Paper disks, 6.35 mm in diameter, were soaked in Richard's solution containing selective inhibitors (5 μg/ml Cu from cupric sulfate, 5 μg/ml active benomyl, 100 μg/ml rose bengal, and 100 μg/ml streptomycin sulfate), then dried at 37C. Treated disks were placed over 4-mm-diameter holes drilled through aluminum plates (7.6 × 10.2 cm, 26 gauge, with three rows of six holes per row), covered, and held in place with vinyl tape, leaving one side of the disks exposed through the holes. Sterilized disk-plates were inserted vertically into soil, incubated, and then recovered. The recovered disks were plated on water agar containing the selective inhibitors, incubated 2 days, and examined for R. solani. Pathogen-free soil artificially infested with graded inoculum concentrations was assayed by the disk-plate and seedling disease methods. Fitted log dosage–probit response curves indicated greater sensitivity for disk-plate than for the seedling-disease method. Best results were obtained with incubations in soil of 5–7 days. Colonization percentages as high as 27.1% (1152 disks) were obtained in field assays of sugar beets affected with naturally occurring rhizoctonia crown rot.
Adenosine metabolism in Micrococcus sodonensis
Authors: Shobe Charles R. , Campbell J. N.
Published: February 2010

Enzymes required for the synthesis of purine ribonucleotides from exogenous adenosine, inosine, and guanosine were shown to be present constitutively in Micrococcus sodonensis. An indirect pathway for the synthesis of adenine nucleotides from adenosine was suggested by the high intracellular adenosine deaminase activity. Concentrations of intracellular adenine nucleotides were elevated in the presence of exogenous adenosine and under those conditions direct measurements of the activity of the pathway for de novo purine ribonucleotide biosynthesis indicated that the activity of that pathway was almost completely inhibited.
S-Adenosylmethionine metabolism by members of the genus Candida
Authors: Balish Edward
Published: February 2010

S-Adenosylmethionine and S-methylmethionine: homocysteine methyltransferase activity was measured in cell-free extracts from seven different species (15 strains) of the genus Candida. All strains were able to form methionine via a transmethylation reaction with S-adenosylmethionine and homocysteine. However, some strains were not able to use S-methylmethionine as a methyl donor. Cell-free extracts from two strains of C. guilliermondii formed no methionine when S-methylmethionine was the methyl donor and one strain (C. guilliermondii, CDC) showed methionine-forming activity with S-adenosylmethionine and homocysteine only when the growth medium was supplemented with L-methionine. In general, greater methyltransferase activity was observed in the cell-free extracts from the more pathogenic members of the genus (i.e., C. albicans and C. tropicalis). Supplementation of the growth medium with L-methionine induced homocysteine methyltransferase activity. Ten of the 15 strains had the capacity to synthesize and store S-adenosylmethionine in their vacuole and all 15 strains had S-adenosylmethionine-degrading enzymes. The activity of the latter enzyme was not increased when cells were grown in L-methionine-supplemented medium.
Dimorphism of Penicillium marneffei as observed by electron microscopy
Authors: Garrison Robert G. , Boyd Karen S.
Published: February 2010

Aspects of the culturally induced mycelial- to tissue-phase transformation of Penicillium marneffei were studied by electron microscopy of thin sections. The hyphal cell was observed to contain multiple, large lipid bodies scattered throughout the cytoplasm. Five days after induction of conversion, short elements arose which were characterized by the presence of two polar areas of vacuolation containing electron-opaque material thought to be altered lipid. This material could not be demonstrated with permanganate fixation, but reacted strongly with thiocarbohydrazide. The latter reagent is known to enhance the electron density of osmium-stained lipids. After 10 days incubation, the tissue-phase cells appeared to be slightly elongate with one or more septa present as the result of division by fission. The cell wall appeared to be of uniform electron opacity with a slightly roughened appearance to the outer surface. Except for residuals of polar vacuolation, the internal morphology of the tissue phase of P. marneffei appeared similar in many respects to that of the analogous yeast-like phases of certain other of the pathogenic dimorphic fungi.
Fungistatic activity of soil sterilized by gamma radiation
Authors: Kusakari Shin-Ichi , Takagi Yasushi
Published: February 2010

Soil fungistasis was completely removed from soil sterilized by gamma radiation.
An unusual strain of Nocardia isolated from an infected cat
Authors: Bakerspigel A.
Published: February 2010

An unusual strain of Nocardia, designated VH/CN-71, was isolated from a pouch-like growth in the inguinal region of a young cat. Although this organism resembles Nocardia brasiliensis in a number of its physiological activities, it appears to be more closely related to a nocardioform organism previously classified by Krasil'nikov (1941) as Proactinomyces mesentericus (Orla-Jensen) Jensen 1932.
Improved purification and further characterization of Clostridium perfringens type A enterotoxin
Authors: Hauschild A. H. W. , Hilsheimer R. , Martin W. G.
Published: February 2010

The procedure for the purification of Clostridium perfringens type A enterotoxin was simplified, and the purity of the toxin was improved. Hydrolysis of the toxin by the p-toluenesulfonic acid procedure yielded 18 common amino acids. Among these, aspartic acid, serine, leucine, and glutamic acid were the predominant components. The sedimentation coefficient (s°20, w) was 2.8 Svedberg units. The molecular weights determined by the Archibald technique, sedimentation equilibrium, and amino acid analysis were 40 000, 36 000, and 33 000, respectively.
The effect of thyroxine and triiodothyronine on bacterial growth
Authors: Garber Nachman , Lupowitz-Donenfeld Batia
Published: February 2010

The effects of L-thyroxine, D-thyroxine, and 3,5,3′-triiodothyronine on the growth of several Gram-positive and Gram-negative bacteria were examined. The first two compounds, at a concentration of 7.7 × 10−5 M, were found to have a considerable inhibitory effect while 3,5,3′-triiodothyronine had a very weak effect on the growth of the Gram-positive bacteria examined. The growth of the Gram-negative bacteria was not inhibited under the same conditions.Potassium iodide, at the same concentration, was not inhibitory. Release of free iodine from the thyroxine preparation was also excluded as contributing to the thyroxine effect because it was shown to be less toxic than thyroxine for Bacillus cereus 569 and to exhibit a similar inhibitory effect on Gram-positive and Gram-negative bacteria.The inhibition of Gram-positive bacteria by L-thyroxine was reduced by cations such as Mn2+, Fe2+, and Ca2+. However, the hormones were more potent in their effect compared to EDTA in the same molar concentration and the inhibition exerted by them was not so easily abolished by the divalent cations as it was in the case of EDTA. Although chelation could contribute to the inhibition of the bacteria by the iodinated hormones, it seems that it is not the only factor involved.
Alkaline phosphatase of Pseudomonas aeruginosa: the mechanism of secretion and release of the enzyme from whole cells
Authors: Ingram J. M. , Cheng K. -J. , Costerton J. W.
Published: February 2010

The release of alkaline phosphatase from whole cells of Pseudomonas aeruginosa as a function of the MgCl2 concentration is proportional to the release of lipopolysaccharide from the cells. Cells grown under conditions where APase is almost completely secreted to the culture filtrate, i.e. growth at pH 7.6, also secrete lipopolysaccharide. Twenty percent sucrose releases a variable quantity of whole cell phosphatase. Localization of this portion of enzyme by biochemical and electron-microscopic techniques showed that it is located on the cell surface exterior to the outer tripartite layer. Phosphatase, which is not released by sucrose, but which is released by MgCl2, is located in the periplasmic space. Phosphatase is located in three areas; the culture filtrate, the outer cell wall surface, and the periplasmic space. The results suggest that A Pase is associated with, and bound to, a cell wall fraction which contains lipopolysaccharide and that the enzyme is "transported" through the outer wall in complex with this fraction. Liberation of the complex from the outer wall may be accomplished by the mechanical shearing forces developed during growth or during the sucrose suspension procedure.