bluuebunny/crossref_metadata_2025 huggingface dataset:
Alkaline phosphatases of Neurospora crassa. Part I
Authors: Davis F. W. J. , Lees Howard
Published: February 2010

The presence of two alkaline phosphatases in mycelial extracts of Neurospora crassa is demonstrated. The two enzymes differ in molecular weight, electrophoretic mobility, and their response to some cations. Neither enzyme is identical with the phosphatase, repressible by inorganic phosphate, known to be present in Neurospora. Both enzymes have an absolute requirement for Zn2+, which is tightly bound to the protein and cannot be replaced by any other ion tested, and for Mg2+, which is loosely bound and can be at least partially replaced by several other ions. The possibility that the two activities represent different states of aggregation of the same subunits rather than two different proteins is discussed.
The effect of ethylenediaminetetraacetic acid on actinobolin-resistance in Escherichia coli
Authors: Hunt D. E. , Sandham H. J.
Published: February 2010

Sensitivity to the antibiotic actinobolin was restored in an actinobolin-resistant strain of Escherichia coli by exposing cells of the resistant strain to an aqueous solution of ethylenediaminetetraacetic acid (0.0004 M) for 10 minutes at 37 °C. This observation suggests that decreased permeability to actinobolin is one mechanism by which E. coli may resist inhibition by this antibiotic.
Powassan virus transmission by ixodid ticks infected after feeding on viremic rabbits injected intravenously
Authors: Chernesky Max A.
Published: February 2010

All stages of Demacentor andersoni (Stiles) ticks were infected by feeding on rabbits injected intravenously with large doses of Powassan virus 48 hours after the ticks became attached. Viremia titers at least 102.5 mouse LD50 per milliliter were required to establish infection in 1 to 5% of D. andersoni ticks whereas Ixodes pacificus (Cooley and Kohls) ticks required 100-fold higher titers of viremia to achieve infection. Transstadial transfer of Powassan virus was observed through ecdysis of larvae to nymphs and from nymphs to adults. Transovarial transfer was not detected. Transmission of Powassan virus to a guinea pig was demonstrated by the bite of D. andersoni nymphs which were infected by ingestion of viremic blood by their antecedent larvae 8 weeks before.
Survival of root-infecting fungi in soil. XIII. Decomposition of flavonoids and other phenolics in soil and their effects on Fusarium root rot of bean
Authors: Lewis J. A. , Papavizas G. C.
Published: February 2010

The flavonoids rutin and quercetin and two of their decomposition products, phloroglucinol and protocatechuic acid, were rapidly degraded in soil. Less than 10% of their phenolic nuclei were detected in soil, and from 27 to 57% of their structural carbons remained in soil after 9 weeks of incubation. Phenolic intermediates were not detected in soils amended with rutin or quercetin. There were no differences in the decomposition of any of the substrates in noninfested soil and in soils infested with F. solani f. sp. phaseoli. In pure culture, two virulent isolates of the pathogen could effectively metabolize a glucose–rhamnose mixture and protocatechuic acid, but only one of the isolates could use phloroglucinol and rutin to any great extent. When incorporated into soil at a rate of 0.1% and 0.3%, rutin, phloroglucinol, protocatechuic acid, and a glucose–rhamnose mixture significantly increased propagule numbers of the pathogen over that of the control. From 1 week, to the termination of the experiment after 9 weeks, more than 80% of the propagules of F. solani f. sp. phaseoli existed in the soils as chlamydospores. Propagule numbers were higher in soils amended with 0.3% substrate than in soils amended with 0.1% substrate, and the numbers 1 week after amendment addition were similar to those obtained 9 weeks after amendment addition. In the first and second crops of beans (planted 3 and 6 weeks after amendment incorporation), protocatechuic acid and phloroglucinol, at a concentration of 0.3%, were very effective in reducing root-rot severity. The other amendments, except quercetin, were effective in suppressing disease to various degrees. The effectiveness of the various amendments depended upon amendment concentration and time of planting. Quercetin, added to soil at either concentration, did not increase inoculum density but did increase disease severity.
Evaluation of shikimic acid as a precursor of pyocyanine
Authors: Ingledew W. M. , Campbell J. J. R.
Published: February 2010

The availability of a new resuspension medium and the isolation of a strain of Pseudomonas aeruginosa unable to use quinic acid for growth have facilitated the evaluation of shikimic and quinic acids as precursors of pyocyanine. Shikimic acid or its derivatives were shown to account for virtually 100% of the carbon atoms of the phenazine nucleus of pyocyanine. The portion of the aromatic pathway where the branch point leading to pigment synthesis appears to occur has been indicated by competition experiments.
Experimental nephritis due to type specific streptococci. VI. Further characterization of type 12 nephrotoxin
Authors: Fardy P. W. , Matheson B. H. , Reed R. W.
Published: February 2010

Additional studies were undertaken on the nature of a nephrotoxic agent found in the culture filtrates of certain group A streptococci. A commercially available dehydrated medium proved satisfactory for the production of the active material. Gel filtration was used to divide polypeptide extracts, prepared from the dialyzable portion of culture filtrates, into two major fractions. One of these, representing the higher molecular weight components, contained most of the nephrotoxic activity as evidenced by the development of hypertension and acute glomerulonephritis in rabbits injected with this fraction.Physical and chemical studies indicated that the active fraction consisted of at least four polypeptide components separable by high voltage electrophoresis on paper. Automatic amino acid analysis of an acid hydrolysate of this fraction revealed 17 different amino acids. Carbohydrate was not detected by anthrone and orcinol tests.No relationship was established between this streptococcal nephrotoxic agent and other streptococcal constituents which have been implicated in acute glomerulonephritis.
Adenovirus-12 transformation of gerbil lung cells
Authors: Shaw Gloria J. , McFarlane E. Sandra
Published: February 2010

The transformation of gerbil lung cells by adenovirus-12 has been obtained. These virus-free cells produce the T-antigen and are capable of preventing adenovirus-12 oncogenesis in hamsters. In addition, they possess an increased tRNA methylase activity which may be another marker for in vitro viral transformation.
Characterization of Haemophilus vaginalis, Corynebacterium cervicis, and related bacteria
Authors: Vickerstaff Janice M. , Cole Barry C.
Published: February 2010

The genital tract bacteria, previously classified as Haemophilus vaginalis and Corynebacterium cervicis and their suggested variant forms, have been characterized by morphology, physiology, and cell wall composition. The strains of H. vaginalis did not form a homogeneous taxonomic group. Only the Dingham strain of Amies and Jones and a Gram-negative culture of strain GP2 of Edmunds were related to the genus Haemophilus. H. vaginalis strain GP7 and the Gram-positive culture of GP2 were corynebacteria. The remaining strains of H. vaginalis were distinct from each other and from the Haemophilus group. None of the strains of C. cervicis could be identified with the genus Corynebacterium. The O strains of C. cervicis were related to the genus Haemophilus, whereas the T strains of C. cervicis and the NCTC strain of H. vaginalis (10287) shared properties with Actinomyces bovis. The two diphtheroids D5 and D17 from a culture of Mycoplasma hominis type 2 (Mycoplasma arthritidis) were dissimilar to each other; D17 was a typical Corynebacterium, whereas D5 was unrelated to the corynebacteria, but similar to the T strains of C. cervicis.
A new resuspension medium for pyocyanine production
Authors: Ingledew W. M. , Campbell J. J. R.
Published: February 2010

A medium for the production of the phenazine pigment pyocyanine by Pseudomonas aeruginosa has been developed. The medium was deficient in phosphate and contained ammonium chloride, inorganic salts, and 2-ketogluconate as sole carbon source. Rapid initiation of pigment formation was observed with synthesis being completed at 24 h. Kinetics of growth, substrate concentration, pigment elaboration, and phosphate liberation have been examined. In the presence of excess nitrogen pigment concentration was proportional to the level of 2-ketogluconate used.
Effect of interferon on Sindbis virus growth in chick-embryo cell cultures
Authors: Stewart Robert B. , Sheaff Edward T.
Published: February 2010

A study of the effect of interferon on the growth of Sindbis virus in cultures of chick-embryo cells has shown that interferon forms an association with cells (uptake) and that the action of interferon is concentration rather than amount dependent. Evidence has also been obtained that interferon acts to reduce the yield of virus from cells, but does not reduce the number of cells synthesizing virus (all or none effect).
Inhibition of nitrifying bacteria by grass and forb root extracts
Authors: Neal Jr. J. L.
Published: February 2010

Root extracts of six climax species of grasses and eight species of grasses or forbs that increase on or invade overgrazed land were bioassayed for the presence of substances which inhibit nitrifying bacteria. Inhibitors were detected in root extracts of grasses and forbs that commonly increase on or invade overgrazed grasslands.
Isocitrate lyase in Coprinus lagopus (sensu Buller)
Authors: Casselton P. J. , Fawole M. O. , Casselton L. A.
Published: February 2010

Isocitrate lyase activity was detected in cell-free extracts of both a monokaryon and a dikaryon of Coprinus lagopus sensu Buller grown in media containing either acetate or glucose as carbon source. The activity in extracts of mycelium grown in an acetate medium was greater than that in extracts of mycelium grown in a glucose medium but marked differences between extracts of monokaryons and dikaryons grown in similar media were not observed. The isocitrate lyase activity could be largely sedimented by centrifugation at 10 000 × g for 20 minutes.
Peptides for transformability of a streptococcus
Authors: Pakula R. , Iler Deanna
Published: February 2010

The Challis streptococcus could not be transformed to streptomycin-resistance with homologous deoxyribonucleic acid (DNA) when grown in two chemically defined media. However, addition of peptides to these media resulted in high transformability.
The ultrastructures of autotrophically and heterotrophically grown Thiobacillus novellas
Authors: Caeseele L. Van , Lees H.
Published: February 2010

Studies of heterotrophically and autotrophically grown Thiobacillus novellas (A.T.C.C. 8093) showed several differences in cell structure. The envelope of the heterotrophically grown cell appeared as a homogeneous three-layered structure. The envelope of the autotrophically grown cell under the same fixing and staining procedure also appeared as a three-layered structure; however, differences were evident in the outermost layer of the two envelopes. Chemical analysis and specific staining procedures suggested that globules present in the heterotrophic cells were made up of polysaccharide.
Ineffectiveness of viomycin-resistant mutants of Rhizobium meliloti
Authors: Hendry G. S. , Jordan D. C.
Published: February 2010

Under clearly defined conditions one-step acquisition of viomycin resistance by a normally effective strain of Rhizobium meliloti resulted in one-step acquisition of ineffectiveness in nitrogen fixation, which probably occurred with a one-gene change in the R. meliloti genome. Two-step mutants retained their ability to produce root nodules but such nodules also were ineffective. Increased sensitivity of the viomycin-resistant mutants to glycine and D-alanine was not noted. Bacteroids were not seen in nodules formed by the viomycin-resistant mutants on their homologous host plant. Nitrogenase activity was not detected, by acetylene reduction, in detached ineffective nodules, whereas effective nodules formed 10.6 μmoles of ethylene per hour per gram of nodules. Growth of the effective parent strain in a low concentration of viomycin resulted in elongation and swelling of the cells so that they appeared as artificially produced bacteroids. Viomycin-resistant mutants did not undergo this transformation. Antigens could be readily extracted by hot- and cold-saline extraction of wet packed cells of both resistant and sensitive cultures but antigenic differences, which may have indicated cell wall differences, were not noted.
The variations in the antigenic composition of Mycobacterium tuberculosis during the growth cycle as measured by the passive hemagglutination and precipitation reactions
Authors: Turcotte R.
Published: February 2010

The erythrocyte-sensitizing ability (ESA), as measured by the bis-diazotized-benzidine hemagglutination test, was determined for the extractable and culture filtrate antigens of three strains of mycobacteria (H37Rv, H37Ra, and BCG). The ESA of the precipitated and supernatant fractions obtained from these preparations by precipitation with ammonium sulfate, was found to vary according to the age of the cultures: the concentration of antigens decreased in the bacillary extracts and increased in the corresponding culture filtrates with the aging of the mycobacterial cultures.The variation in the antigenic composition of bacterial extracts and of culture filtrates during the growth cycle was also demonstrated by immunodiffusion techniques in agar gel. However, all extractable antigens of a given Mycobacterium did not appear in the culture filtrates.
The chitinase of Serratia marcescens
Authors: Monreal Jaime , Reese Elwyn T.
Published: February 2010

Serratia marcescens was found to be the most active organism of 100 tested for the production of chitinase. Enterobacter liquefaciens produced nearly as much enzyme. Under optimal conditions high yields of chitinase were obtained in 4–6 days. The S. marcescens enzyme system is extracellular and is composed of an endochitinase, a chitobiase, and a factor (CH1) required for the hydrolysis of "crystalline" chitin. As such, it closely resembles the cellulase system of Trichoderma viride, and differs from those chitinolytic systems which act only on degraded forms of chitin. The absence of other hydrolytic enzymes in the S. marcescens filtrates makes this a useful system for determining the role of chitinase as a lytic agent.
Purification and properties of endo-β-glucanase in the yeast Hanseniaspora valbyensis
Authors: Abd-El-Al Ahmed T. H. , Phaff H. J.
Published: February 2010

Endo-β-glucanase was detected in Hanseniaspora valbyensis and Hanseniaspora uvarum. The extracellular enzyme activity of H. valbyensis was maximal with vigorous aeration at 30 C in a complete mineral medium with glucose and 0.2 M Na-succinate buffer. The enzyme concentration was lower when the buffer was 0.05 M Na-succinate. The use of a variety of carbon sources, including yeast cell walls, failed to induce higher enzyme activities. The enzyme was purified 34-fold from the culture fluid of H. valbyensis. The purified enzyme had a broad pH optimum between pH 3.5 and 4.5. Among the known β-glucan homopolymers, only laminarin (β-1 → 3 bonds) was hydrolyzed by the enzyme. The Km for laminarin was 0.11 mg/ml and the Vmax was 0.835 μmoles glucose equivalents/min mg protein. No action was detected with laminaribiose, laminaritriose, or oat glucan. Laminaritetraose, however, was hydrolyzed slowly in a random pattern. These results suggest the requirement for three consecutive β-1 → 3 bonds for activity.
The cytological effects of myxin on Escherichia coli
Authors: Stevenson I. L.
Published: February 2010

When actively growing cells of Escherichia coli 15T− were treated with the new antibiotic myxin, the effects produced by the antibiotic varied, depending on the concentration. With a concentration of 1 μg/ml, the action was bacteriostatic for the first 60 min exposure. Cell division was inhibited but there was no apparent effect on macromolecular synthesis as evidenced by the formation of filamentous cells. At higher concentrations (3 and 5 μg/ml), myxin was bactericidal although some cell elongation occurred at the 3 μg/ml level. Microscopic examination of cells treated with 3 and 5 μg/ml for 30–45 min indicated the presence of vacuolated areas which thin section studies revealed as intracellular ramifications of the plasma membrane. Protoplasts of cells grown in the presence of 5 μg/ml myxin were enlarged or rapidly lysed even after as little as 15 min exposure. Myxin has no effect on the cell surface of control protoplasts. No abnormal development of the plasma membrane was noted in the elongated cells formed in the presence of 1 μg/ml myxin. Except for the lack of septation during the first 60 min, the filamentous forms appeared normal with well-defined nuclear bodies distributed throughout the cell.
Studies on Stigmatella brunnea
Authors: McCurdy Howard D. , Khouw Boen Tie
Published: February 2010

Fruiting body formation by Stigmatella brunnea is induced by Ca2+ or Mg2+ containing media deficient in amino acids. The morphology of the fruits is quite variable and the conclusion is reached that Stigmatella brunnea and Podangium erectum may be identical. The resting cells have a definite slime capsule, are heat resistant, and are induced by glycerol and therefore may be considered to be microcysts. Their arrangement in the cysts is random.For liquid culture cultivation S. brunnea requires casitone, 0.5% starch, and magnesium. Although starch and certain sugars stimulate growth, they are not used.Growth was obtained in a medium containing 17 amino acids when thiamine was supplied. On this medium, however, there was a long lag and the yield was only 60% of that on casitone medium.The results of enzyme and respiration studies are consistent with the operation of the tricarboxylic acid cycle with a complete terminal electron-transport pathway.
Characterization of a protein-lipopolysaccharide complex released from cell walls of Pseudomonas aeruginosa by ethylenediaminetetraacetic acid
Authors: Rogers S. W. , Gilleland Jr. H. E. , Eagon R. G.
Published: February 2010

Results from analytical ultracentrifugal analysis, Sephadex gel filtration, isopycnic density-gradient centrifugation, and polyacrylamide disc-gel electrophoresis revealed that ethylenediaminetetraacetic acid liberated a protein–lipopolysaccharide complex from cell walls of Pseudomonas aeruginosa with an estimated molecular weight of not less than 160 000 and probably about one million. Electron microscopy of this complex revealed spherules and rodlets. The diameter of the former was approximately 70 ± 10 Å while the dimensions of the latter were 70 ± 10 Å × 200 ± 50 Å. The rodlets appeared to be composed of three or more spherules arranged in a chain-like fashion. Electron microscopy of protein-free lipopolysaccharide revealed predominantly hollow spheres from 300 Å to 1500 Å in diameter, morphologically resembling membrane sacculi. It is proposed that the protein–lipopolysaccharide complex, but not the protein-free lipopolysaccharide, is representative of the in situ form of native endotoxin.
Role of extracellular ribonuclease in growth of Corynebacterium acnes
Authors: Smith Rodney F.
Published: February 2010

Corynebacterium acnes produces an extracellular nuclease which degrades ribonucleic acid. Growth was stimulated in peptone medium without glucose by the addition of ribonucleic acid and was related to the amount of ribonucleic acid depolymerized. Among other bacteria examined nuclease production was not always associated with the stimulation of growth by ribonucleic acid. Growth of C. acnes in peptone broth was stimulated by xanthine and guanine. Growth was not initiated in a basal nucleic acid free (NAF) medium by the addition of several nucleic acid metabolites nor in the NAF basal medium containing only 0.05% yeast extract. Growth occurred when the NAF–yeast extract base was supplemented with ribonucleic acid or other nucleic acid metabolites. Ribose and ribonucleic acid were equal in growth-supporting ability. Some purine bases in combination with glucose or ribose also supported growth. Other bases such as adenine or cytosine were not stimulatory but their ribotides were. Ribonuclease functioned as a growth stimulating enzyme by its action on ribonucleic acid under certain cultural conditions. Ribose appears to be a major stimulating metabolite made available from nucleic acid breakdown. Other components such as ribotides or nucleic acid bases, particularly purines, will also support growth in media devoid of these compounds or lacking them in sufficient concentration.
The detection of various bacteria indicative of water pollution by a presence–absence (P–A) procedure
Authors: Clark J. A.
Published: February 2010

Results of a previously described presence–absence (P–A) test were compared with those of the membrane filter (MF) technique for detecting fecal coliforms, coliforms, and anaerogenic coliforms in municipal drinking water samples. The P–A test allowed more frequent isolation of these organisms and, when supplemented by simple confirmatory tests, could also indicate the presence of fecal streptococci, green fluorescent pseudomonads, Aeromonas species, and Clostridium perfringens. In the absence of coliform detection, the occurrence of these other bacterial groups could give warning of unusual fecal or organic pollution.A comparison of coliform and non-coliform isolates from MF and P–A tests indicated that similar organisms were detected by both methods. The finding of false-positive "sheen" colonies was attributable to the presence of ethyl alcohol in the MF Endo medium. Although organisms giving rise to such colonies were non-coliforms, their presence was suggestive of inadequate water treatment.
The effect of isonicotinic acid hydrazide on clavine alkaloid biosynthesis
Authors: Hsu Joan Chen , Anderson John A.
Published: February 2010

Agroclavine, elymoclavine, and chanoclavine are the major alkaloids produced in submerged cultures of Claviceps purpurea PRL 1980. Clavine alkaloid biosynthesis is depressed by isonicotinic acid hydrazide. When isonicotinic acid hydrazide is added during the period of alkaloid synthesis, the ratio agroclavine/elymoclavine decreases and the proportion of compound b in the mixed alkaloid product increases.
Adenovirus-12 transformation of human foreskin cells
Authors: Shaw Gloria J. , McFarlane E. Sandra
Published: February 2010

Human foreskin cells previously infected with adenovirus-12 showed characteristics of transformation such as the production of T-antigen, prevention of adenovirus-12 induced tumor formation, and increased tRNA methylase activity. However, these transformed human foreskin cells showed no morphological changes.
The chemical inhibition of an enzyme induced germination of bacterial spores
Authors: Parker M. S.
Published: February 2010

Spores of Bacillus subtilis germinate rapidly in phosphate buffer upon the addition of the enzyme subtilopeptidase-A. This enzyme induced germination is inhibited by p-choloro-m-cresol. The effects have been found of preincubating intact spores with the inhibitor, of preincubating enzyme with the inhibitor, and of preincubating spores, enzyme, and inhibitor together. In every case when the inhibitor is suitably neutralized the spores will germinate normally.
The influence of Bordetella pertussis on the preparation of mouse spleens for the secondary immune response
Authors: Finger H. , Emmering P. , Brüss E.
Published: February 2010

The simultaneous injection of 4 × 108 sheep erythrocytes and 3 × 109 killed cells of Bordetella pertussis effects an accelerated and prolonged multiplication of antibody-forming spleen cells if compared with mice immunized with the erythrocyte antigen only. If mice of both groups are given a second injection of 4 × 108 sheep erythrocytes 6 weeks later, the numbers of indirect plaque-forming cells are markedly increased in pertussis-treated mice. This is connected with enhanced 7 S serum hemolysin titers. The conclusion is drawn that an initial injection of B. pertussis prepares the lymphoid tissues of mice for the secondary immune response.
Growth inhibition of a Staphylococcus aureus aminopterin-derived thymineless mutant by exogenous nucleosides in the presence of thymine
Authors: Mathieu L. G. , Repentigny J. de , Turgeon S. , Sonea S.
Published: February 2010

Adenosine partially inhibits growth of Staphylococcus aureus Wood 46 parent strain because of feedback inhibition, whereas uridine has no effect. However, adenosine and uridine completely block the growth of an aminopterin-derived thymineless mutant of the Wood 46 strain in the presence of thymine; the site of inhibition seems to be located at the level of thymidine synthesis from thymine, since (1) normal growth is restored when thymidine is used instead of thymine; (2) deoxyuridine monophosphate cannot be converted into thymidine monophosphate by interconversion, thymidylate synthetase being inoperative in the thymineless auxotroph.
Enzymatic lysis of vegetative cells of Bacillus popilliae and other sporeformers
Authors: Hrubant G. R. , Rhodes R. A.
Published: February 2010

Spores of Bacillus popilliae were isolated from a mixture of spores and vegetative cells by enzymatic digestion of the vegetative cells. Infectivity of the enzyme-treated spores was not affected and germination was enhanced. The enzyme complex, produced extracellularly by an aerobic sporeformer, also induced spheroplasts of B. popilliae. Vegetative cells of bacteria in 13 of 23 genera were lysed by the enzyme but sporulating forms of all sporeformers tested were not. Thus, the enzyme can be used for the discriminate selection of sporangial stages of sporulation by the specific lysis of vegetative forms.
Some nutritional and environmental factors affecting growth and production of sclerotia by a strain of Aspergillus niger
Authors: Agnihotri V. P.
Published: February 2010

The effects of two nutritional elements (carbon and sulfur) and two environmental factors (pH and temperature) on growth and sclerotial production of Aspergillus niger were determined on a synthetic agar medium. The fungus grew and produced sclerotia under laboratory conditions on media containing wide ranges of carbon and sulfur sources. Of the 20 carbohydrates tested, only ribose, mannitol, and malonic, fumaric, and citric acids failed to induce production of sclerotia. A synergistic effect was observed on the formation of sclerotia when favorable and unfavorable carbon sources were supplied in different combinations. Of the 14 sulfur compounds tested, magnesium sulfate yielded the highest and sodium sulfite the lowest number of sclerotia. Raising the concentration of magnesium sulfate to 3 g/l increased the number of sclerotium initials and the number and dry weight of those which matured. In general, no correlation occurred between the number of sclerotia formed and their dry weights on different carbon or sulfur sources. Sclerotia were most numerous at pH 7.0 and 35 °C.
Cytopathogenicity and replication of human adenovirus type 6 in cultured bovine cells
Authors: Liao S. K. , Weber J.
Published: February 2010

Multiplication of human adenovirus type 6 was demonstrated in established cultures of bovine cells. The virus replicated, producing characteristic cytopathic effects and undiminished infectivity, through six serial passages. By means of light and electron microscopy the appearance of viral inclusion bodies were comparable to those routinely observed in infected human cells. Intranuclear paracrystalline formations were also observed in the present virus–host system. The pathogenicity and host range of human adenovirus type 6 in relation to these properties of other adenoviruses were discussed.
Properties of Pseudomonas iodinum
Authors: Colwell R. R. , Citarella R. V. , Ryman I. , Chapman G. B.
Published: February 2010

From results of Adansonian, deoxyribonucleic acid base composition, and fine structure studies of Pseudomonas iodinum, it is suggested that this organism be removed from the genus Pseudomonas. The cell wall structure of P. iodinum was found to be typical of the Gram-positive bacteria. Inclusion bodies were observed in cell sections and were found to be located at or near the septum and mesosomes of the cells.
Photoinduced perithecial formation by Nectria haematococca on media containing either L-tyrosine; L-phenylalanine; or D-glucose + NaNO3 as sole carbon and nitrogen sources
Authors: Curtis C. R.
Published: February 2010

A homothallic isolate of Fusarium solani produced red perithecia when illuminated and grown on a simple basal medium containing L-tyrosine; L-phenylalanine; or D-glucose + NaNO3 as a sole carbon and nitrogen source. Few or no perithecia formed in darkness on these media. Quantitative comparisons of perithecial formation in illuminated treatments indicated that L-tyrosine was a significantly better sole source of carbon and nitrogen than either L-phenylalanine or D-glucose + NaNO3. There was no significant difference between the responses on media containing L-phenylalanine and D-glucose + NaNO3. If dark-grown treatments were subsequently illuminated, perithecia formed on media containing L-tyrosine and D-glucose + NaNO3 but not on L-phenylalanine. The initial pH of the medium containing L-tyrosine did not seem to affect the fruiting response in illuminated cultures. A reduction in the amount of L-tyrosine in the basal medium resulted in a corresponding decrease in perithecial formation.The results are discussed in connection with a possible relationship of sexual reproduction, the light requirement, and tyrosine metabolism.
Quantitative study of fungi in the rhizosphere
Authors: Parkinson D. , Thomas A.
Published: February 2010

Working with dwarf bean plants, the authors studied changes in the lengths of fungal mycelium in rhizosphere and non-rhizosphere soil at different stages of plant growth, using the soil-agar film technique. In general it appears that the stimulation of microbial growth in the rhizosphere was slight in the early stages of plant growth; the length of mycelium in rhizosphere soil increased with increase in vegetative growth of the plants, and decreased markedly at senescence of the plants.Respirometric studies on rhizosphere and non-rhizosphere soil samples indicated greater activity in rhizosphere soil. The degree of stimulation of activity in rhizosphere soil varied according to the stage of plant growth, with maximum activity corresponding to the stage of maximum vegetative growth of the plants.
The relationship of pathogenic coagulase-negative staphylococci to Staphylococcus aureus
Authors: Smith Harriet B. H. , Farkas-Himsley Hannah
Published: February 2010

Coagulase-negative pathogenic staphylococci were studied physiologically and serologically to determine their relationship to Staphylococcus aureus. When 46 characters were studied and tallied, the 21 coagulase-negative pathogenic strains made up a heterogeneous intermediate group sharing not all the characters of S. aureus but appreciably more than S. epidermidis. Some characters among the coagulase-negative pathogens indicating a relationship to S. aureus were serotyping, lysostaphin sensitivity, growth rates, and endogenous respiration. Seventy-one percent of the coagulase-negative pathogenic strains were resistant to penicillin; of these, 80% were multiple antibiotic resistant.From these results it would appear that the genus Staphylococcus cannot be divided satisfactorily into demarcated species but that strains within this genus form a continuous spectrum between the two presently recognizable extremes with new subtypes evolving as characters are lost. If a species must be designated under the existing system of classification, a strain producing coagulase can be called S. aureus. However, coagulase-negative pathogenic strains cannot be classified with accuracy as S. epidermidis on the basis of the absence of this single character, coagulase.
Production of aflatoxin by Aspergillus wentii Wehmer
Authors: Schroeder H. W. , Verrett M. Jacqueline
Published: February 2010

Two cultures of Aspergillus wentii isolated from white field corn were tested through three consecutive single-spore generations for the ability to produce aflatoxins. Aflatoxin production by A. wentii was established. Production was low and variable. The variability was apparently not due to inhomogeneity in the parent culture. The identity of aflatoxin B1 was confirmed by chemical derivative tests and by the chick embryo bioassay. The ability to accumulate, as well as to produce, the aflatoxins is suggested as an additional requirement to qualify a fungus as an aflatoxin producer.
Étude du rôle des sucres dans la résistance des pommes de terre au flétrissement bactérien
Authors: Paquin Roger , Pelletier Guy
Published: February 2010

Potato resistance to ring rot does not seem to be related to sugars present in stems and tubers in opposition to the conclusions of Rozhalin. Sugars contained in those organs exceed the amount required by the causal agent, Corynebacterium sepedonicum (Spieck. & Kott.) Skapt. and Burkh., for its growth. Moreover, no correlation could be shown between sugar content and varietal resistance. Sugars added to potato extracts did not influence the growth of C. sepedonicum on these extracts. Moreover, a rise of the storage temperature of potato tubers which caused a rapid decrease in their sugar content did not influence the growth of C. sepedonicum on extracts of the same tubers.
Experiments in biological and chemical control of Fusarium wilt (F. oxysporum f. melonis (Leach and Currence) Snyd. and Hans.) of muskmelon
Authors: Wensley R. N.
Published: February 2010

Selected antagonistic biota used in the planting medium reduced Fusarium wilt of muskmelon significantly. In combined treatments they augmented control given by fungicidal amendments to infested soil and (or) seed. Combined treatments that consisted of amendments to two or more of the three treatment components, soil, seed, planting medium, frequently were more effective than treatments of one component. Retaining the jiffy pot when transplanting enhanced control given by biological and fungicidal amendments. Under conditions highly favorable for wilt, protection given by antagonistic biota in the planting medium and fungicidal amendments frequently diminished after 35 days. Although reductions in population of the pathogen to low levels did not preclude high plant losses, evidence supports the view that the minimum requirements for satisfactory control include (1) reduction of populations of the pathogen to low levels, (2) continuous protection of the host through interaction of antagonistic biota and residual biota of treated soils, and (3) resistance imparted to the host by systemic action of fungicides. Results encourage the use of the jiffy pot and the planting medium when planting in the field for protecting the plant from injury and to provide a medium in which biological and fungicidal amendments may be applied at any desired time in advance of seeding and transplanting.
Dilatometric study of streptococcal growth and metabolism
Authors: Marquis Robert E. , Fenn Wallace O.
Published: February 2010

A simply constructed dilatometer or volumeter was used to measure small volume changes (ca. 6 × 10−4 ml per milliliter) accompanying growth of Streptococcus faecalis cultures. Polymerization reactions involved in cell synthesis appeared to contribute little to the observed changes, and dilatation of cultures in glucose-containing media could be interpreted mainly in terms of volume changes associated with cleavage of glucose to lactic acid, ionization of lactic acid, and protonation of buffer ions in the culture. Glycolysis in suspensions of nongrowing cells was accompanied by similar increases in volume. In contrast, arginine degradation by S. faecalis was accompanied by contraction, and in this case the volume change could be almost completely accounted for by differences in partial molar volumes of products and reactants. Possible relationships between metabolic volume changes and pressure sensitivity of bacteria are discussed.
Interaction of interferon with cells: induction of antiviral activity
Authors: Sheaff Edward T. , Stewart Robert B.
Published: February 2010

A study of interferon–cell interaction has shown that interferon becomes associated with cells (uptake) and that this association is partly reversible. It was further found that "uptake" of interferon was induced by low concentrations of interferon and that this process required host cell messenger ribonucleic acid (mRNA) and protein synthesis. The results of this study are interpreted as indicating that interferon itself is the viral inhibitory substance and the protein induced by interferon is associated with interferon transport.
A survey of genomic maps in strains of Staphylococcus aureus
Authors: Altenbern Robert A.
Published: February 2010

Six randomly selected strains of Staphylococcus aureus all exhibited the same gene order along the chromosome when mapped by the synchronous chromosomal replication procedure. Strains possessing multiple antibiotic resistance yielded a genomic map with all genes shifted toward significantly later replication times than in strains not bearing multiple antibiotic resistance. It appears that there is a unique site on the S. aureus chromosome for the initiation of replication.
The rhizosphere of an aquatic plant (Lemna minor)
Authors: Coler R. A. , Gunner H. B.
Published: February 2010

Dominant epiphytes colonizing the surface of Lemna minor were identified and enumerated. The distribution of these organisms compared to populations on inert surfaces at depths 0, [Formula: see text], 1, 2, 4 and 8 in. revealed greater than a 100-fold increase in population density. This enhanced carrying capacity of the plant diminished with depth.
Interferon stimulation of methylase activity in L-cells
Authors: Rozee K. R. , Katz L. J. , McFarlane E. Sandra
Published: February 2010

Treatment of L-cells with interferon results in a rise in tRNA methylase activity and this phenomenon may have a direct bearing on translation control exercised by the interferons.
Anaerobic degradation of some bioflavonoids by microflora of the rumen
Authors: Simpson F. J. , Jones G. A. , Wolin E. A.
Published: February 2010

The microflora of the bovine rumen under anaerobic conditions rapidly degraded bioflavonoids such as rutin, quercitrin, naringin, and hesperidin to water-soluble products. Phloroglucinol was detected as a transitory intermediate in the fermentation of rutin, quercitrin, and naringin, but not hesperidin. Other unknown phenolic compounds were also produced. Protocatechuic acid was decarboxylated to yield catechol, and catechol was not degraded.
Mode of action of viomycin on Rhizobium meliloti
Authors: Jordan D. C. , Yamamura Y. , McKague M. E.
Published: February 2010

The biochemical mechanism of action of viomycin on R. meliloti involved an inhibition of protein synthesis. Adenine and amino acid incorporation into total nucleic acid and cell wall respectively was relatively unaffected. The antibiotic increased the level of 14C in the intracellular pool and "nucleic acids" fraction of cells fed 14C-amino acids but caused no cellular lysis. Mono- and di-valent cations protected cells from growth inhibition by viomycin.A viomycin-resistant mutant was similar to its sensitive parent in rate of uptake of glucose and glutamic acid by both growing and resting cells and in the rate of leakage when preloaded cells were suspended in buffered saline. Viomycin resistance did not appear to be episome-mediated or involve an extracellular degradative enzyme. The ability of TES buffer to eliminate viomycin resistance, coupled with the sensitivity to viomycin of cell-free protein-synthesizing systems derived from both sensitive and resistant cells indicates that resistance is probably the result of a selective reduction in antibiotic permeability.
Studies with fluoride-sensitive and fluoride-resistant strains of Streptococcus salivarius. I. Inhibition of both intracellular polyglucose synthesis and degradation by fluoride
Authors: Hamilton Ian R.
Published: February 2010

Sodium fluoride (0.48 mM) completely inhibited intracellular polyglucose synthesis by resting cells of Streptococcus salivarius incubated anaerobically with glucose. Inhibition was complete if fluoride was preincubated with the cells before the addition of the substrate or if added during active synthesis. However, the degradation of the intracellular material in the absence of exogenous glucose continued at an appreciable rate at 15 times this NaF concentration. The degree of fluoride inhibition of both polyglucose degradation and synthesis was increased as the pH of the reaction mixture decreased. The rate and quantity of the intracellular polysaccharide synthesized during subsequent incubations with glucose in the absence of NaF was not reduced significantly by preincubating the cells with NaF up to 2.4 mM. However, both parameters were reduced by prior exposure to 4.8 mM NaF.Fluoride-resistant cells, obtained either by stepwise selection or by ultraviolet-induced mutation, synthesized polyglucose in the presence of 2.4 mM NaF at rates and amounts only slightly less than those of control cells incubated in buffer free of this inhibitor. Furthermore, the ability of resistant cells to synthesize polyglucose in the presence of high NaF levels was retained despite growth for 300 generations in medium free of sodium fluoride. The ultraviolet-induced strains synthesized polyglucose at greater rates and amounts than the stepwise selected cells, suggesting that they differ in the nature of their resistance.
Studies with fluoride-sensitive and fluoride-resistant strains of Streptococcus salivarius. II. Fluoride inhibition of glucose metabolism
Authors: Hamilton Ian R.
Published: February 2010

Low concentrations of sodium fluoride inhibited use of exogenous glucose by washed cells of the homofermentative oral microbe Streptococcus salivarius whether added before or after the substrate. Complete inhibition of exogenous glucose metabolism was achieved by NaF concentrations above 0.96 mM. Inhibition of glucose uptake caused an immediate reduction in the lactic acid formed as a result of metabolism, although the percentage conversion of glucose to lactic acid was not altered by fluoride at levels below 0.24 mM. Above this concentration, short periods of non-stoichiometric lactate formation were observed but continued incubation in the presence of fluoride always resulted in the production of normal quantities of lactic acid. Fluoride inhibition of glucose metabolism was pH-dependent with complete inhibition by 0.12 mM NaF occurring at pH values below 6.0. Sufficient fluoride was absorbed by cells at fluoride concentrations above 1.2 mM in a 30-minute period to reduce significantly subsequent glycolytic activity by the cells in medium free of the inhibitor.Mutants resistant to 2.4 mM NaF were shown to degrade glucose in the presence of 2.4 and 4.8 mM NaF at rates 74–46% of that of the control cells grown in the absence of this inhibitor. Growth of these resistant cells for 300 generations in medium free of fluoride stimulated the rate of glucose metabolism in the presence of 2.4 mM NaF, but exposure to 4.8 mM NaF reduced the rate of activity to 30% of that of the same cells incubated at 2.4 mM NaF. Comparison of the fluoride sensitivity of exogenous glucose metabolism and of endogenous polyglucose degradation have indicated that the prime site of fluoride action in these cells was at some point before glucose-6-P formation, possibly involved with the glucose transport process, the phosphorylation of glucose by hexokinase or an associated reaction. This conclusion was confirmed in recent experiments which demonstrated that the addition of low concentrations of fluoride to cells incubated with glucose resulted in an immediate reduction in the intracellular level of glucose-6-P.
The use of cell wall immunizing antigens for serological study of Streptomyces species
Authors: Guthrie Rufus K. , Taylor Gerald R.
Published: February 2010

Soluble cytoplasmic fractions and washed cell wall fragments from Streptomyces species cultures were compared as immunizing antigens for preparation of antisera. The anti cell wall serum gave fewer cross reactions between species, and thereby appears to be the better reagent for use in evaluation of serological relationships.
Fermentation of natural gas with a cyclone column fermenter
Authors: Mueller J. C.
Published: February 2010

A mixed flora, capable of using natural gas as a carbon substrate, was derived from a laboratory sewage sludge. Fermentations in a cyclone column fermenter, on a 1:1 natural gas/air mixture, resulted in a doubling time of 4.6 h and production of 0.065 mg dry cell mass per square centimeter interfacial area per hour. Foaming problems limited cell concentrations to 6.1 g/l.
Reversion of the MR variant of Candida albicans
Authors: Ireland Rosalee , Sarachek A.
Published: February 2010

Previous studies have indicated that the minute-rough (MR) colonial variant of Candida albicans arises through mutation of an extrachromosomal hereditary determinant. The MR variant's high rate of reversion to the wild-type condition suggests either that (a) the determinant undergoes frequent spontaneous repair or that (b) variant cells bear both normal and mutant determinants which segregate at cell division. Analyses presented here of the effects of growth rate, nutrition, incubation temperature, and metabolic antagonists upon reversion favor the view that reversion is due to repair of mutant determinants.
Ultrastructural aspects of spore germination and outgrowth in Clostridium sporogenes
Authors: Hoeniger Judith F. M. , Headley C. L.
Published: February 2010

The process by which dormant spores of Clostridium sporogenes are transformed into vegetative cells has been studied in thin sections with the electron microscope. The resting spore appears very similar to that of other Bacillaceae for it possesses a rather featureless core which is surrounded by a core membrane, cortex, and spore coat(s); beyond lies a sac-like exosporium. At an early stage in germination the core becomes differentiated into peripheral areas of nuclear material and a ribosome-packed cytoplasm; a germ cell wall develops beyond the core membrane. The later stages of germination coincide with the beginning of outgrowth: the cortex disintegrates into a sponge-like mass of fibrils, and the young cell grows while still retained within the unbroken spore coats. The young cell now has a fibrillar nucleoplasm, a ribosome-rich cytoplasm, an occasional mesosome, a plasma membrane, and a relatively thick cell wall. Subsequently, the cortex vanishes completely, and the new vegetative cell elongates and finally emerges terminally through the spore coats and the exosporium. The exosporium of C. sporogenes consists of two layers: a thick inner one which is laminated, and a thin outer one possessing a fringe of hair-like projections.
Antigenic relationships of various fractions of the Ehrlich ascites tumor investigated by different immunoserological methods
Authors: Eng C. P. , Hindmarsh J. A. , Morgan J. F.
Published: February 2010

Antisera against the ascites fluid, cytoplasmic fluid, insoluble cell fraction, and sonic extract of the Ehrlich ascites tumor were prepared in rabbits. The antiserum against the ascites fluid produced a number of precipitation lines in the immunodiffusion test with the ascites fluid, but exerted no cytotoxic effect on viable tumor cells in the Warburg manometer test. The antiserum against the insoluble cell fraction did not produce precipitation lines in the immunodiffusion test, yet it was very cytotoxic to the tumor cells. Among these four ascites tumor preparations, the insoluble cell fraction displayed the best immunoprotective effect, and the cytoplasmic fluid appeared to suppress the hemagglutinin production against sheep erythrocytes in rabbits. All four ascites tumor preparations shared some antigenicity with the mouse erythrocyte as demonstrated by the hemagglutination test.