bluuebunny/crossref_metadata_2025 huggingface dataset:
Mutualistic degradation of the lignin model compound veratrylglycerol-β-(o-methoxyphenyl) ether by bacteria
Authors: Crawford Ronald L.
Published: April 2010

Complete degradation of the lignin model compound veratrylglycerol-β-(o-methoxyphenyl) ether is accomplished mutualistically by a two-membered bacterial culture. Bacterial isolate E1, which has been tentatively identified as an Acinetobacter, grows on veratrylglycerol-β-(o-methoxyphenyl) ether producing guaiacol (o-methoxyphenol) as a non-metabolizable, bacteriocidal by-product. When Nocardia corallina (strain A81) is also present in media containing veratrylglycerol-β-(o-methoxyphenyl) ether as the only carbon/energy source, it is able to grow on the guaiacol produced from veratrylglycerol-β-(o-methoxyphenyl)ether by isolate E1. Strain A81 alone does not grow on veratrylglycerol-β-(o-methoxyphenyl) ether. In the absence of strain A81, isolate E1 is rapidly killed by accumulated guaiacol. In the presence of the Nocardia, isolate E1 maintains its viability.
Characterization of a reserve glucan from Megasphaera elsdenii
Authors: Brown Robert G. , Lindberg Bengt , Cheng K.-J.
Published: April 2010

A reserve glucan of Megasphaera elsdenii was studied by methylation analysis before and after treatment with isoamylase. The results of this study indicate that the glucan is of the amylopectin–glycogen type.
Gonococcal growth factors in tissue cultures
Authors: Ashton F. E. , Charron F. , Ota F. , Wallace R. , Diena B. B.
Published: April 2010

Growth of Neisseria gonorrhoeae in the presence of Rhesus monkey kidney (RE2) cells containing Eagle's minimal essential medium (MEM) 'conditioned' by 18–20 h of contact with RE2 cells began 3–4 h after inoculation and by 16–20 h had reached a maximum. When 'conditioned' medium (CM) was removed from the tissue cells and replaced with fresh medium a 5–6 h lag period occurred before multiplication of gonococci began and by 16 h growth was also near a maximum. CM removed from tissue cells supported the growth of six strains of N. gonorrhoeae. Three strains failed to grow in CM but multiplied when tissue cells were present. None of the strains grew in the presence of tissue cells killed by heating or in tissue-culture medium alone.Of the six strains of N. gonorrhoeae which grew in CM, three kept as their major (90%) population T1 colonies, while the remaining strains produced T1 organisms and T1A, T3, and T4 colonial variants.These results indicate that tissue cells secrete growth factors which support the growth and maintenance of T1 colonial forms of certain strains of N. gonorrhoeae.
Identification and flagellation of coryneform bacteria from poultry litter
Authors: Antheunisse J. , Vonkeman H.
Published: April 2010

Thirty coryneform isolates from poultry litter were identified and checked for motility and flagellation. Twenty-seven formed a yellow pigment and 3 were orange. Twenty-three yellow strains were found to be Arthrobacter citreus, although starch was hydrolyzed by these strains. Four strains, including the three mainly pale yellow isolates, grew on citrate plus an ammonium salt and were classified as A. aurescens. Three orange strains were found to be Brevibacterium linens. Only six strains of A. citreus were motile. These strains displayed flagellated rods after l day and flagellated cocci after 5 days incubation. The flagellar shape and arrangement were studied. Non-motile strains never showed flagella after staining.
A model system for studying protein–lipopolysaccharide synthesis, assembly, and insertion in the outer membrane of Pseudomonas aeruginosa
Authors: Stinnett J. D. , Eagon R. G.
Published: April 2010

Ethylenediaminetetraacetate (EDTA) has been previously shown to cause the release of a complex of protein and lipopolysaccharide (PrLPS) from the outer membrane of Pseudomonas aeruginosa. In this present work, cells of P. aeruginosa were incubated in a solution of EDTA, phosphate buffer, and hypertonic sucrose to prepare osmoplasts (osmotically sensitive cells). Osmoplasts were able to undergo self-repair of the outer-membrane damage resulting from EDTA treatment and to regain osmotic stability when incubated in growth medium/hypertonic sucrose for 2 h in the absence of exogenous PrLPS and in the absence of cell division. This repair process was inhibited by either chloramphenicol or KCN. Examination of freeze-etched preparations demonstrated that 40% of the PrLPS units in the outer membrane were removed by EDTA; after 2 h in growth medium/hypertonic sucrose, cells were able to repair this damage by synthesizing and inserting new PrLPS units into the outer membrane. Osmoplasts could also be restored to osmotic stability by suspension in osmoplast supernatant fluid containing PrLPS and Mg2+. This latter restoration process, which was not inhibited by chloramphenicol or KCN, was purely physical while the self-repair restoration process was metabolic. These data are consistent with the concept that the outer membrane proteins, especially the PrLPS units, play a role in stabilizing the cell envelope and in maintaining the osmotic stability of P. aeruginosa.
The lipids of four unusual non-pathogenic host-associated spirochetes
Authors: Livermore Brian P. , Johnson Russell C.
Published: April 2010

The lipid compositions of two spirochetes isolated from the human oral cavity and two isolated from pig feces were examined. These isolates were unusual in that they did not require long-chain fatty acids for growth, as do the other host-associated spirochetes, but rather required isobutyric and valeric acids. Therefore, they could be cultured in a medium free of serum or fatty acid –albumin supplements. The major fatty acids synthesized were normal and iso fatty acids with 14 and 16 carbons. No unsaturated fatty acids were detected, nor were chain lengths longer than 16 carbons. The major complex lipids found were monogalactosyl diglyceride, phosphatidyl glycerol, and bis-phosphatidyl glycerol. Nitrogenous phospholipids, present in Treponema and Leptospira, were not synthesized by these novel strains. The data indicate an intermediate position of these isolates between Treponema and free-living Spirochaeta.
Nutrition of Vitreoscilla stercoraria
Authors: Mayfield D. C. , Kester A. S.
Published: April 2010

The present study has shown that the glutamate or aspartate families, plus the aromatic amino acid family are required for growth of Vitreoscilla stercoraria. Furthermore, glutamine can substitute for the glutamate family, asparagine and methionine can replace the aspartate family, and tyrosine can substitute for the aromatic family. Amino acids which are easily oxidized by this organism, particularly serine and cysteine, stimulated growth. From these data, a defined medium was devised, which contained the fewest amino acids that could support good growth of V. stercoraria.
Temperature-induced alanine oxidation in a psychrotrophic Pseudomonas
Authors: Zachariah Prince K. , Liston John
Published: April 2010

A psychrotrophic pseudomonad isolated from iced fish oxidized alanine at temperatures close to 0 °C and grew over the range 0 °C–35 °C. The rate of oxidation of alanine, measured manometrically, by cells grown at 2 °C was lower than that of cells grown at 22 °C. However, the consumption of oxygen after heat treatment at 35 °C for 35 min was reduced considerably by 2 °C grown cells. Alanine oxidase activity was tested in an extract from cells grown at 2 °C and 22 °C with alanine as the sole carbon, nitrogen, and energy source. Cells grown at 2 °C produced an alanine oxidase with a temperature optimum of 35 °C and pH optimum of 8, which lost about 80% activity by heat treatment at 40 °C for 30 min. There was no change in activity after dialysis at pH 7, 8, or 9. Extracts from cells grown at 22 °C contained an alanine oxidase system with an optimum temperature of 45 °C, a pH optimum above 8, and only about 30% reduction of activity after heat treatment. This enzyme activity was concentrated in the 0.5 M elution fraction from a Sephadex column, and dialysis reduced the activity at pH 7 and 8. Mesophilic enzyme synthesis apparently started around a growth temperature of 10 °C.The crude alanine oxidase systems of Pseudomonas aeruginosa derived from cells grown at 13 °C and 37 °C had a common optimum temperature of 45 °C. These data suggest that one mechanism of psychrophilic growth by psychrotrophic bacteria may be the induction of enzymes with low optimum temperatures in response to low temperature conditions.
Microcycle conidiation in Penicillium urticae: an ultrastructural investigation of conidiogenesis
Authors: Sekiguchi J. , Gaucher G. M. , Costerton J. W.
Published: April 2010

A cultivation system has been developed for Penicillium urticae which yields 'microcycle' conidiation in submerged culture. Spherical growth of spores was initiated by incubation at 37 °C in a growth-favoring medium. Transfer of these enlarged spores to a nitrogen-poor medium at 35 °C results in synchronous germination and limited outgrowth followed by roughly synchronous conidiation. A study of the conidiation stage showed that a phialide and an immature conidium began to form at the tip of all germ tubes 18 h after the temperature shift. By 24 h additional phialides commonly appeared as a branch near the tip of the germ tube and the more mature conidia exhibited increasing refractility. The earliest ultrastructural signs of conidiation were various round invaginations in the plasma membrane and a thickening and rounding of the new spore wall which appeared as an inner extension of the phialide cell wall. Upon segregation of the conidium from the phialide cell by conidial wall formation, 'trench-like' invaginations gradually appeared in the plasma membrane and a disorganized rodlet pattern was formed on the outer surface of the maturing conidial wall. Continued maturation involved the formation of chains of conidia and phialide senescence which was characterized by a general degradation of intracellular structure. A comparison with standard surface and submerged culture conidiation indicated that 'microcycle' conidiation, while less prolific, was essentially identical.
Development of amino acid uptake activity in Neurospora
Authors: Railey Robert M. , Kinsey John A.
Published: April 2010

During the germination and growth of Neurospora conidia, amino acid permease systems I (neutral) and II (general) increase in specific activity. System III (basic) decreases in specific activity with the onset of germination. System I shows two peaks of activity during the logarithmic phase of growth. One peak occurs at 6 h, the other at 12 h of growth. Both peaks are abolished in the mtr mutant. Both peaks have a Km for phenylalanine of 40 μM. The peaks of system I activity appear to correlate with morphological changes.
Products of anaerobic phloroglucinol degradation by Coprococcus sp. Pe15
Authors: Tsai Chii-Guary , Gates Diane M. , Ingledew W. M. , Jones G. A.
Published: April 2010

Under anaerobic conditions, resting cell suspensions of Coprococcus sp. Pe15 degraded 1 molecule of phloroglucinol to 2 molecules of acetic acid and 2 molecules of carbon dioxide. The organism metabolized the flavonoids rhamnetin and quercetin anaerobically in 20% rumen fluid medium but failed to grow under similar conditions at the expense of any of 39 other aromatic or flavonoid compounds tested.
The nuclear DNA-dependent ribonucleic acid polymerases of the dermatophytic fungus Microsporum gypseum
Authors: Dill Barbara C. , Stock J. J.
Published: April 2010

The DNA-dependent RNA polymerases of the dermatophytic fungus Microsporum gypseum were partially characterized. Nuclear extracts prepared from vegetative mycelia were fractionated by DEAE-Sephadex chromatography into three enzyme species which resembled in most of their characteristics those of other eukaryotic organisms.
Morphology and host range of virulent phages of lotus rhizobia
Authors: Patel J. J.
Published: April 2010

Nineteen virulent bacteriophages for fast- and slow-growing rhizobia were isolated. Most of the phage isolates were of two morphological types, and these showed specificity for either the fast- or the slow-growing rhizobia. The ecological distribution, morphology, and host range of the phages is presented. Classification of lotus rhizobia is discussed on the basis of phage typing.
The accumulation of succinate by the yeast Brettanomyces bruxellensis
Authors: Sanfaçon Roger , Roulliard Roger , Heick H. M. C.
Published: April 2010

The metabolism of Brettanomyces bruxellensis was investigated to determine the metabolic block responsible for the accumulation of acetate seen in cultures of this yeast. In glucose-grown cultures the major non-volatile intracellular organic acid was succinic acid. These cultures also had low levels of succinic dehydrogenase (succinate dehydrogenase, EC 1.3.99.1) and did not produce CO2 from the carbons of ethanol. It was concluded that a block in the oxidation of ethanol occurred at the level of succinic dehydrogenase. If glucose-grown cultures were transferred to ethanol medium, the block in the metabolism of ethanol was partially overcome; the level of succinic dehydrogenase increased, the concentration of the intracellular succinate decreased, and CO2 could be produced from C-1 of ethanol.
Degradation of homogentisate by strains of Bacillus and Moraxella
Authors: Crawford Ronald L.
Published: April 2010

The metabolic pathways whereby strains of Moraxella and Bacillus degrade homogentisate (2,5-dihydroxyphenylacetate) are delineated. The Moraxella (strain OA3) is shown to degrade homogentisate via the pathway previously described in liver: homogentisate is cleaved by a 1,2-dioxygenase (E.C 1.13.11.5) yielding maleylacetoacetate which is isomerized by a GSH-dependent isomerase to fumarylacetoacetate before hydrolysis to acetoacetate and fumarate. A strain of Bacillus (B11c) is shown to catabolize homogentisate via a previously undescribed version of the above sequence: homogentisate is cleaved by a 1,2-dioxygenase (E.C 1.13.11.5) yielding maleylacetoacetate which is hydrolyzed directly to acetoacetate and maleate.
Resistance of Thiobacillus novellus to mitomycin C and rifampicin
Authors: Chow C. T.
Published: April 2010

Thiobacillus novellus is highly resistant to mitomycin C and rifampicin. This resistance is not due to insusceptibility of the target molecules to the drugs, since mitomycin C cross-links the DNA and rifampicin inhibits the DNA-dependent RNA polymerase of T. novellus in vitro.
Some chemical and structural features of the conidial wall of Trichoderma viride
Authors: Benítez T. , Villa T. G. , Acha I. García
Published: April 2010

Cell wall of spores of Trichoderma viride contains polymers similar to those of mycelial cell wall, such as β-(1 → 3), β-(1 → 6)glucans and protein, but chitin, always present in the mycelium, cannot be found in spores. Melanin, which in other fungi appears associated with chitin, replaces this polymer in the spore wall of T. viride and is located in the outermost layer. Attempts to characterize the pigment of the spore wall indicate that it is a non-indolic melanin-like polyphenol.
Production of β-(4-hydroxyphenyl)ethanol and β-(4-hydroxyphenyl)lactic acid by Candida species
Authors: Narayanan T. K. , Rao G. Ramananda
Published: April 2010

Two crystalline compounds were isolated from the culture filtrates of Candida species grown in synthetic medium supplemented with L-tyrosine as the sole source of nitrogen. These compounds were characterized as β-(4-hydroxyphenyl)ethanol (HOPEA) and β-(4-hydroxy-phenyDlactic acid (HOPLA). The production of these compounds in five species (both pathogenic and non-pathogenic) was compared and marked differences were revealed. Experiments using L-[14C]tyrosine indicated that both HOPEA and HOPLA are synthesized from L-tyrosine.
Ultrastructural changes in Cladosporium cucumerinum during pathogenesis
Authors: Laborda F. , Maxwell D. P.
Published: April 2010

Three ultrastructural patterns, each one associated with a different stage of pathogenesis, were observed in Cladosporium cucumerinum infecting cucumber cytoledons. (i) Fungal prepenetration structures (conidia and germ tubes) contained numerous lipid bodies. Microbodies were abundant and often associated with lipid bodies. Mitochondria were also abundant. (ii) During the invasion stage, no lipid bodies and relatively few microbodies were observed. Mitochondria were abundant, but differed markedly morphologically from those observed in the prepenetration structures. (iii) In the colonizing hyphae, microbodies were the most abundant organelle, lipid bodies were seldom found, and mitochondria were as observed during invasion. These changes in numbers of organelles may be associated with differences in the metabolic activities of the pathogen at various stages of pathogenesis.
Sucrose-mediated giant cell formation in the genus Neisseria
Authors: Johnson K. G. , Mcdonald I. J.
Published: April 2010

Growth of Neisseria perflava, Neisseria cinerea, and Neisseria sicca strain Kirkland in media supplemented with sucrose (0.5 to 5.0% w/v) resulted in the formation of giant cells. Response to sucrose was specific in that a variety of other carbohydrates did not mediate giant cell formation. Giant cells appeared only under growth conditions and did not lyse upon transfer to medium lacking sucrose or upon resuspension in hypotonic media. Reversion of giant to normal cells occurred when giant cells were used as inocula and allowed to multiply in media lacking sucrose.
Frothy feedlot bloat in cattle: production of extracellular polysaccharides and development of viscosity in cultures of Streptococcus bovis
Authors: Cheng K.-J. , Hironaka R. , Jones G. A. , Nicas Thalia , Costerton J. W.
Published: April 2010

Streptococcus bovis was cultured in a synthetic medium with three concentrations of sucrose. Initial viscosity of the media was 1.5 centipoise (cp). After incubation for 8 h, the viscosity of the medium with 0.5% sucrose was unchanged, that with 3% sucrose had increased to 8 cp, and that with 6% sucrose to 112 cp. Similar results were found with a rumen fluid medium. A slimy material, responsible for increased viscosity of these cultures, was digested by dextranase. The material appeared as a complex system of intercellular fibers when viewed under the electron microscope after freeze-etching. With proteins and other polymers released from lysed bacteria, this slimy material may contribute directly to increased viscosity and foam formation. In addition to these intercellular fibers, each cell was surrounded by a fibrous capsule that was not digested by dextranase. This capsule stained with lead citrate and uranyl acetate, but not with ruthenium red. The amount of capsular material produced was similar whether the media contained 0.5, 3.0, or 6% sucrose.
Somatic nuclear division in the sporidia of Ustilago violacea. IV. Microtubules and the spindle-pole body
Authors: Poon N. H. , Day A. W.
Published: April 2010

In unbudded cells of the anther smut fungus Ustilago violacea there is a dome-shaped spindle-pole body (SPB) consisting of a core 0.1 μm in diameter surrounded by a ribosome-free region 0.3–0.4 μm in diameter lying in a pocket of the nuclear membrane. After budding the nucleus moves towards the bud and begins to rotate rapidly. At about this stage the SPB divides into two parallel bars each about 0.1–0.15 μm in diameter and 0.3 μm long, separated by a distance of about 0.3 μm. Microtubules associated with the nuclear membrane but not with the SPB are present at the time of nuclear rotation. These microtubules disappear when rotation stops. Microtubules attached to the SPB are found during migration of the chromatinic portion of the nucleus into the bud cell. These microtubules disappear when migration stops and the nuclear membrane begins to break down. The twin SPB bars appear to move into the nucleus through a break in the membrane and begin to move apart forming a spindle about 1 μm long. Chromosomal microtubules (one per kinetochore) were found in several serial sections, and in addition there appeared to be several continuous microtubules present. The separation of the two chromatinic masses appeared to result from elongation of the continuous microtubules to about 3 μm long. Cytoplasmic microtubules and spindle microtubules were both found attached to the SPB as it elongated and one nucleus returned to the mother cell.The paper concludes with a discussion of the SPB as a multifunctional control center affecting nuclear migration, spindle formation, membrane breakdown and synthesis, karyogamy, conjugation, budding, chromosomal movement, replication, and disjunction.
Temperature-induced alterations in phospholipids of Fusarium oxysporum f. sp. lycopersici
Authors: Barran Leslie R. , Miller Richard W. , Roche Ian de la
Published: April 2010

Ten phospholipids were identified in hyphal membrane preparations of Fusarium oxysporum f. sp. lycopersici when the cells were grown to the late log phase at 15, 25, and 37 °C, respectively. The major phospholipids present were phosphatidylcholine (PC) and phosphatidylethanolamine (PE), which together made up about 70% of the total membrane phospholipids. The degree of unsaturation in the acyl group of the phospholipids was inversely related to growth temperature. The polar head group composition was also affected by growth temperature. Cells grown at 15 and 25 °C contained the same relative proportions of PC and PE, but when the growth temperature was raised to 37 °C, the ratio of PC to PE was doubled. A methylating system capable of converting PE to PC was demonstrated in vitro.
Ultrastructure of melanin formation in Verticillium dahliae with (+)-scytalone as a biosynthetic intermediate
Authors: Wheeler M. H. , Tolmsoff W. J. , Meola S.
Published: April 2010

Transmission and scanning electron microscopy showed that melanin of wild-type Verticillium dahliae occurred as granules in microsclerotial cell walls and in a fibrillar network encapsulating the walls. An albino microsclerotial mutant and a brown microsclerotial mutant of V. dahliae did not form melanin granules. When albino microsclerotia were treated with (+)-scytalone (a metabolite that the brown mutant accumulates), they formed melanin granules and turned black. These granules were similar in appearance and distribution to those in the wild type. Melanin granules of the wild-type isolate and the scytalone-treated albino mutant were formed at a maximum rate in microsclerotia from 5- to 8-day-old cultures. These observations suggest that scytalone is a natural intermediate of melanin synthesis in V. dahliae.
Further studies on the relative antiviral efficacies of interferons induced by polyI:C and Mengo virus
Authors: Campbell J. B.
Published: April 2010

Mouse serum interferons induced by polyI:C, vesicular stomatitis virus (VSV), reovirus, and Mengo virus were assayed in monolayers of mouse L-929 cells by the plaque-reduction method using both VSV and Mengo as challenge viruses. Titers obtained with Mengo virus as challenge were all lower than with VSV. With the interferons induced by VSV, reovirus, and polyI:C, the reductions were of the order of two- to three-fold. With Mengo virus-induced interferon the reduction was much greater (about 17-fold). This offers an explanation for the observation that, unit for unit (measured by the plaque reduction of VSV), Mengo virus-induced interferon is only about [Formula: see text] as effective as polyI:C-induced interferon in protecting mice against lethal infection with Mengo virus. The data are consistent with the hypothesis that an interferon antagonist is produced in the serum of mice infected with Mengo virus. This antagonist, which is not produced in mice inoculated with polyI:C, or reovirus, effectively blocks the antiviral action of interferon during Mengo virus infections, both in vivo and in vitro.
Regulation of acetyl-CoA synthetase of Saccharomyces cerevisiae
Authors: Coleman John S. , Bhattacharjee J. K.
Published: April 2010

Acetyl-coenzyme A synthetase (EC 6.2.1.1) activity of Saccharomyces cerevisiae was determined by a radioactive assay procedure. The activity in vitro was inhibited significantly by NADPH, NADH, or AMP and to a lesser extent by NADP, NAD, or ADP. Glutamic acid and α-ketoglutaric acid were not inhibitory. The enzyme level was repressed when the cells were grown in a complex nutrient medium as opposed to the minimal medium. However, a glutamic acid auxotroph glul, when grown in excess glutamic acid, demonstrated a fivefold increase of acetyl-CoA synthetase.
Comparative zone electrophoresis of esterases of Staphylococcus species isolated from mammalian skin
Authors: Zimmerman Raymond J. , Kloos Wesley E.
Published: April 2010

The electrophoretic mobilities of non-specific esterases in vertical polyacrylamide slab gels were determined for 184 strains of staphylococci, representing a total of 18 proposed species and subspecies. Markedly uniform esterase patterns were seen within species demonstrating a high degree of human host specificity, while those species demonstrating a wide host range were polytypic and often showed considerable polymorphism. The unique banding patterns found in several species indicate that this technique may serve as a valuable aid to existing taxonomic schemes. Starch gel electrophoresis of representative strains usually produced sharper esterase bands than were found with polyacrylamide electrophoresis. However, the additional molecular-sieving effect produced by the polyacrylamide gels differentiated esterases to a greater extent.
Use of mutants to establish (+)-scytalone as an intermediate in melanin biosynthesis by Verticillium dahliae
Authors: Bell A. A. , Puhalla J. E. , Tolmsoff W. J. , Stipanovic R. D.
Published: April 2010

Melanin biosynthesis in Verticillium dahliae Kleb. was studied with mutants deficient for normal black melanin or for production of microsclerotia. Seven genetically different mutants had apparent blocks in melanin biosynthesis. Four mutants (brm-I to -4) produced brown microsclerotia and extruded pigments into media; three (alm-1 to -3) produced albino microsclerotia. Other mutants produced no microsclerotia (nms) or had greatly reduced numbers of microsclerotia (rms). Mutation alm-1 was due to a single recessive gene; the other melanin-deficient characters were recessive but their genetic bases were not determined. Cultures of the brown mutants brm-1 and -3 extruded and accumulated a metabolite that blackened the albino microsclerotia of alm-1 to -3. The metabolite was identified as (+)-scytalone (3, 4-dihydro-3, 6, 8-trihydroxy-1(2H)naphthalenone). Pigment formed by alm-1 microsclerotia from (+)-scytalone had chemical and physical properties identical with those of melanin in the wild-type fungus. (+)-Scytalone was produced and converted to melanin by microsclerotia but not by conidia or hyphae. Conversion of (+)-scytalone to melanin appeared to involve two or more enzymes and probably involved conversions to 1, 3, 8-trihydroxynaphthalene and 1, 8-dihydroxynaphthalene. Albino mutants of Thielaviopsis basicola, Drechslera sorokiniana, Pleospora infectoria (Alternaria), Ulocladium sp., and Curvularia sp. also converted scytalone to pigments indistinguishable from the melanins found in their respective wild types. Scytalone melanin may be common in fungi with dark brown or black pigments.
Effects of temperature on the growth of psychrophilic bacteria from glaciers
Authors: Gounot A. M.
Published: April 2010

Growth of five strains of psychrophilic bacteria (four Arthrobacter and one Pseudomonas) isolated from glacial deposits was studied at different temperatures. Three strains were facultative psychrophiles, having an optimum temperature for growth at about 25–28 °C and a maximum at about 32–34 °C. The two Arthrobacter glacialis strains were found to be obligate psychrophiles with an optimum at 13–15 °C and a maximum at 18 °C. Arrhenius plots showed that A. glacialis could compete with the facultative psychrophilic bacteria only at 0 °C, that is, the temperature of its natural environment. The psychrophilic Arthrobacter species studied here are more resistant to thermal stress than are marine psychrophilic bacteria.For Arthrobacter, in contrast to Pseudomonas, temperatures above the optimum induced formation of filaments and abnormal cells. The culture turbidity increased 10 to 30 times, whereas viable count tended to decrease. The thermal block seems to prevent cell wall synthesis and septation, but at a different step for each species.
Lysogeny in Streptococcus bovis
Authors: Iverson W. G. , Millis Nancy F.
Published: April 2010

Forty-eight strains of Streptococcus bovis were tested for induction with mitomycin C. Eleven inducible strains were found and the lysates of all 11 contained bacteriophage-like particles. The lysate of one strain also contained large numbers of particles which closely resembled polyheads. Eight of the lysates produced zones of inhibition on indicator strains and viable bacteriophages were detected in six lysates. The sources of the S. bovis were ovine and bovine rumen fluid (23 strains), ovine and bovine feces (5 strains), blood cultures from human endocarditis (8 strains), and a wide variety of other sources (12 strains). Only 1 of 23 rumen S. bovis strains was lysogenic, which suggests that lysogenic S. bovis strains are not an important source of bacteriophages in the rumen.
Long-chain n-alkanes occurring during microbial degradation of petroleum
Authors: Walker J. D. , Colwell R. R.
Published: April 2010

Five axenic cultures and a mixed culture were examined for ability to degrade South Louisiana, Brass River Nigerian, Anaco Venezuelan, and Altamont crude oils. A wax was observed during microbial degradation of Altamont crude oil, but not during weathering of the oil. The high-boiling n-alkanes in the wax were associated with microbial degradation of the oil and appeared to be similar to components of tarballs found in the open ocean.
Nitrogen fixation in the muskeg ecosystem of the James Bay Lowlands, Northern Ontario
Authors: Blasco Judith A. , Jordan D. C.
Published: April 2010

The acetylene-reduction assay was used for in situ and laboratory assessment of biological nitrogen fixation in the acidic, waterlogged, muskeg ecosystem of the southern James Bay area, in the region of Moosonee, Ontario. In situ assays and subsequent laboratory experimentation revealed that nitrogenase activity was predominately a function of the activities of heterocystic blue-green bacteria associated with surface water, with the phyllosphere of mosses, and with at least one lichen, a species of Peltigera. No such in situ activity was detected in the subsurface organic material, even when such material was amended with glucose. However, under laboratory conditions at 20 °C, nitrogenase activity was evident in the subsurface layers after an extended lag and was shown to be higher under anaerobic than under aerobic conditions, to have an optimum temperature range extending about a mean of 20 °C, and to be stimulated by glucose. This potential for subsurface nitrogen fixation proved to be related to the presence of microorganisms existing in anaerobic microsites within the organic layers and no microorganisms capable of fixation could be detected under aerobic incubation.
The conversion of leucine to α-ketoisocaproic acid and its metabolic consequences for Escherichia coli K12
Authors: Newman E. B. , Adley T. , Fraser J. , Potter R. , Kapoor V.
Published: April 2010

The amino acid L-leucine serves as a good auxiliary nitrogen source for Escherichia coli K12, and in so doing is converted to alpha-ketoisocaproic acid which is excreted into the medium.L-Leucine does not serve as sole nitrogen source. Cells incubated with L-leucine as sole nitrogen source do not grow, although they do metabolize leucine, and accumulate ketoisocaproic acid in the medium.Where glycine is the only other nitrogen source, the presence of L-leucine greatly increases the growth rate even at concentrations so low that its contribution as nitrogen donor is unlikely to be important.
Differences in physicochemical and antigenic properties of chlamydial strains
Authors: Sayed H. , Fung K. , Wilt J. C.
Published: April 2010

Antigenic analysis of Chlamydia psittaci, C. trachomatis, and Lymphogranuloma venereum (LGV) revealed basic physicochemical differences among the three chlamydial strains. These were manifested in structural, isoelectric points, absorption spectra, and in the characteristics of the chromophobe-containing proteins. The effective period of sonication for C. psittaci and C. trachomatis is around 60 min during which the linkages most susceptible to external sonication forces were broken, releasing all attainable cellular components. Denaturation studies demonstrated that less than 50% of protein content of C. psittaci was denatured after 1 h of sonication, only 5% in the case of C. trachomatis. The protein and carbohydrate content of the most reactive fractions in macrophage-spreading inhibition test were different for LGV and C. trachomatis. The structural differences appear to determine the antigenic properties observed among the chlamydial strains as well as the specificity and probably the mechanisms (s) of cellular immune reactivity to Chlamydiae. This in turn may explain the failure of chlamydial vaccines, prepared from stock strains, to protect immunized children against 'wild' chlamydial strains.
The fatty acid composition of some Entomophthoraceae. IV. The occurrence of branched-chain fatty acids in Conidiobolus species
Authors: Tyrrell David , Weatherston John
Published: April 2010

The presence of branched-chain fatty acids was confirmed in 6 of 18 Conidiobolus species examined. Amounts varied from about 9% of total fatty acids in C. parvus to about 73% in C. adiaeretus, and in all cases included acids of the even-carbon-numbered iso series and the odd carbon-numbered anteiso series.
Reproducibility of vitamin assays with mutants of Neurospora crassa maintained by freeze-drying
Authors: Jong S. C. , Davis E. E.
Published: April 2010

Three mutant strains (ATCC 9277, ATCC 9278, ATCC 9683) of Neurospora crassa requiring choline, inositol, and p-aminobenzoic acid respectively for normal growth were deposited at the ATCC by G. W. Beadle 30 years ago and were preserved at various time intervals by freeze-drying. Each preservation batch yielded cultures that, when used for biological assays, exhibited the same biochemical properties as they originally possessed. The freeze-drying technique is shown to be applicable to preserving biological properties of sporulating fungi for bioassay over prolonged periods of time.
Activité métabolique de Candida lipolytica adsorbé sur bentonites à chaînes hydrophobes
Authors: Pareilleux A. , Maignan C.
Published: April 2010

The respiration of Candida lipolytica on n-tetradecane is decreased in the presence of bentonite. This inhibition is less pronounced by the introduction of hydrophobic chains on the bentonite. Oxygen demand of resting cells varies with the length of hydrophobic chains. In fermentor, addition of adsorbant does not stimulate growth, but assimilation of n-tetradecane is enhanced with certain concentrations of the adsorbant. On glucose, addition of hydrophobic chains on the adsorbant does not change the effects of bentonite on exogenous respiration and substrate assimilation.
Toxicity and plant growth regulator effects of cytochalasin H isolated from Phomopsis sp.
Authors: Wells John M. , Cutler Horace G. , Cole Richard J.
Published: April 2010

A biologically active metabolite was found in crude extracts of an unidentified species of Phomopsis isolated from weevil-damaged pecans. Purified metabolite was toxic to day-old cockerels, with an LD50 of 12.5 mg/kg, and was markedly inhibitory to growth and floral development of tobacco plants at concentrations of 10−2 to 10−4 M. IR and 1H-nmr spectra indicated an alkylphenyl moiety with a single nitrogen atom present as a secondary amide: and acetate ester, OH, CH3, and a trans-double bond function. Elemental and high-resolution mass-spectral analysis indicated a formula of C30H39NO5 and a molecular weight of 493.2886. The metabolite was identified as cytochalasin H.
In vitro binding of sterols by extracts from Mucor rouxii cells grown under different environmental conditions
Authors: Safe S. , Caldwell J.
Published: April 2010

Aqueous cell wall and cytoplasm extracts from Mucor rouxii cells grown under aerobic and anaerobic (oxygen-limiting) conditions were obtained. Both of the extracts from the anaerobic and aerobic cells solubilized lanosterol and ergosterol but not to the same extent; ergosterol was complexed about 2–3 times greater than the same concentration of lanosterol. It was also apparent that the relative binding capacities of the cell extracts were dependent on the cell growth environment. Two additional fractions were obtained from each extract by (a) methanol precipitation and (b) refluxing in 2% aqueous potassium hydroxide solution followed by methanol precipitation. The binding activities of these precipitates and the corresponding precipitates from yeast extract were compared and the results indicated a range of binding activites which depended on both the extract and the sterol. The data suggested that the in vitro sterol binding of M. rouxii extracts was not due to one particular macromolecule but that a number of compounds were involved in this complexation process.
Uptake of L-proline by Histoplasma capsulatum
Authors: Dabrowa Nina , Howard Dexter H.
Published: April 2010

The uptake and incorporation of L-proline by yeast cells of the dimorphic zoopathogen Histoplasma capsulatum were studied. The amino acid was assimilated in at least two ways: by an active transport system with a Km of 1.7 × 10−5 M and by simple diffusion. The active transport system was stereospecific and severely restricted to neutral aliphatic side-chain amino acids. Certain analogues inhibited L-proline uptake and prevented incorporation of the amino acid into cellular constituents. The inhibition of L-proline uptake by L-leucine was competitive. Since L-leucine and L-proline are seemingly transported by a system with similarcharacteristics, it must be concluded, as originally postulated, that the buckled ring of L-proline, in solution, acts as an aliphatic side chain and that this cyclic amino acid is transported by a system more or less specific for amino acids with neutral aliphatic side chains.
The occurrence of cell-associated enterotoxin B in Staphylococcus aureus
Authors: Miller Richard D. , Fung Daniel Y. C.
Published: April 2010

Cell-associated enterotoxin B was detected in lysates of cells of Staphylococcus aureus S-6 and 4916 disrupted by sonication or lysostaphin treatment. As much as 67% of this total cell-associated toxin was surface-bound, located outside the cytoplasmic membrane, and was released during protoplasting of this organism by lysostaphin treatment in hypertonic medium. The remainder of the cell-associated toxin was termed cytoplasmic and was released during osmotic lysis of the protoplasts. Levels of cell-associated toxin as a function of the age of the cells showed a rapid increase in both surface-bound, cytoplasmic, and total cell-associated toxin levels during the period of active toxin synthesis (late exponential phase of growth). These cell-associated toxin levels then reached a peak as the culture entered stationary phase, at a time corresponding to a decrease in the rate of toxin synthesis, and decreased slowly thereafter.
Dependence of the superficial layers of Spirillum putridiconchylium on Ca2+ or Sr2+
Authors: Beveridge T. J. , Murray R. G. E.
Published: April 2010

Chelating agents disrupted the superficial layers on Spirillum putridiconchylium and adsorption of cationized ferritin indicated that both upper and lower surfaces of superficial layer fragments, as well as the outer membrane surface, possessed areas which were negatively charged. Growth of the bacterium in 1% casamino acids (vitamin free) resulted in cells which were devoid of the superficial layers, and negative staining of these cells revealed an amorphous precipitate together with a vesicular outer membrane component extruding from their surfaces into the medium. Addition of either 1 mM Ca2+ or 1 mM Sr2+ to the growth medium produced the typical regularly structured cell surface, whereas addition of equal concentrations of Li+, Na+, K+, Mg2+, Ba2+, Mn2+, Fe3+, or three polyamines produced the structureless surface.
Indirect microhemagglutination test for varicella–zoster antibody determination
Authors: Mankikar S. D. , Petric M. , Middleton P. J.
Published: April 2010

An indirect microhemagglutination assay (IHA) was devised because of a need to provide an alternative test to complement fixation (CF) for varicella–zoster (V–Z) antibody determination. Human erythrocytes were sequentially treated with 2% glutaraldehyde, 0.04% tannic acid, and 2% pyruvic aldehyde then exposed to sonicated V–Z infected cells. This same tanning procedure was suitable for herpes simplex and Epstein-Barr virus antigen attachment but unsatisfactory for several non-herpes-group viruses. V–Z antibody titres determined by IHA were generally 2 to 16 times higher than CF titres. Cross-reaction with herpes simplex antibody was minimal.
Sparing effect of lithium ion on the specific requirement for sodium ion for growth of Vibrio parahaemolyticus
Authors: Morishita Hideki , Takada Hideo
Published: April 2010

The role of NaCl in the growth of Vibrio parahaemolyticus strain A-55 was investigated. Maximal growth was obtained at 0.5 M NaCl in a synthetic medium. Na+ could not be replaced for growth by any other cations or substances. When the medium was kept isotonic with 0.5 M NaCl by the addition of sucrose, good growth was obtained with 0.1 M NaCl. By reducing the osmotic pressure and decreasing the NaCl concentration from 0.5 M to 0.1 M, the same growth yield was obtained as when using a medium containing 0.02 M NaCl and 0.08 M LiCl. This was not the case with sucrose. Therefore, it is concluded that ionic strength and osmotic pressure are important environmental factors affecting growth. The minimal essential requirement for Na+ for growth of V. parahaemolyticus was 0.003 M, because this was never replaced with any other cations and agents. Hence, requirement for Na+ for growth involves a specific requirement for Na+, ionic strength, and osmotic pressure, respective concentrations being 0.003 M, 0.047 M, and 0.45 M. Osmotic support was required for growth when the concentration of NaCl was decreased to 0.05 M. The effect of ionic strength of monovalent cations other than Na+ on growth was examined at 0.003 M NaCl. Among LiCl, NH4Cl, KCl, and RbCl, Li+ was the most accelerative for growth in the synthetic medium.
The respiratory metabolism of Mycobacterium lepraemurium
Authors: Kato Laszlo , Adapoe Catherine , Ishaque M.
Published: April 2010

The respiratory metabolism of Mycobacterium lepraemurium isolated from Sprague-Dawley rats lepromata using several substrates was investigated. None of the intermediates of the glycolysis cycle as well as of the tricarboxylic acid cycle except succinate was oxidized by purified whole suspensions of M. lepraemurium. Likewise, many sulfur compounds such as cystine, thiourea, thioacetate, thiodiglycol, mercaptosuccinate, and mercaptoethanol were inactive. However, yeast extract and some sulfhydryl compounds, e.g., cysteine, dithioerythritol, dithiothritol, and penicillamine were readily oxidized by murine bacillary suspensions, whereas thioglycolate, thioglucose, and reduced glutathione were oxidized at a slow rate. Succinate was not or was very poorly oxidized by normal cells probably because of impermeability of the cell wall but the addition of succinate to the cell suspensions frozen for 1 min at −40 °C considerably enhanced oxygen uptake over the endogenous value. The oxidation of succinate was unaffected by inhibitors rotenone, atabrine, and amytal but was markedly inhibited by thenoyltrifluoroacetone, antimycin A, 2-N-heptyl-4-hydroxyquinoline-N-oxide, and cyanide. The thiol-binding agents, p-hydroxymercuribenzoate and N-ethylmaleimide were also effective inhibitors of succinate oxidation but the process was not affected by uncouplers dinitrophenol, dibromophenol, pentachlorophenol, and carbonyl-cyanide-m-chlorophenylhydrazone. The results indicated that succinate oxidation by M. lepraemurium was mediated by oxidative enzymes involving an electron transport chain with oxygen as the terminal electron acceptor.
Factors affecting rate of methane formation from acetic acid by enriched methanogenic cultures
Authors: Berg L. van den , Patel G. B. , Clark D. S. , Lentz C. P.
Published: April 2010

A stable enrichment culture converting acetic acid to methane was successfully obtained from a pear waste digester, using a synthetic substrate solution with acetic acid as the main carbon source. This enrichment culture converted up to 10 mmol of acetic acid per litre per day at 35 °C and did not use hydrogen or formic acid in appreciable amounts as substrate for methane production instead of or in addition to, acetic acid. The rate of conversion of acetic acid to methane was maximum at temperatures of 40–45 °C, at a pH of 6.5 to 7.1, and was adversely affected by exposure to air, reducing agents, and high salt concentrations. The rate of conversion was independent of acetic acid concentration between 0.2 and 100 mM, but dropped markedly at concentrations below 0.2 mM.
Respiration rates for determining the effects of urea on the soil-surface organic horizon of a black spruce stand
Authors: Roberge M. R.
Published: April 2010

The respiration rates of microflora of layers of soil-surface organic horizon of a black spruce (Picea mariana (Mill.) B.S.P.) stand have been studied manometrically under controlled conditions of moisture, temperature, and aeration in the presence of urea and other nitrogen and mineral amendments. L, F1, and F2 samples from field plots fertilized with 448 kg N/ha as urea in 1961 had still in 1971 greater respiration rates than similar samples from unfertilized field plots. In lab tests, addition of urea (112, 280, and 448 kg N/ha or 875, 2187, and 3500 ppm N) stimulated the endogenous respiration of each layer. The stimulation was greater when 2187 ppm N was applied and when moisture and temperature of the layers were maintained at 60% water-holding capacity and 20 °C during the 42-day incubation period. Addition of Mg, Ca, and K to urea-fertilized layers increased respiration while P and S decreased it. Addition of NH4NO3 and (NH4)SO4 impaired the endogenous respiration. The endogenous respiration and moisture, temperature, and fertilizer effects decreased in the order L, F1, and F2 layers.
Temperature-sensitive mutants of vesicular stomatitis virus: viral RNA synthesis in cells infected with mutants belonging to complementation group I
Authors: Cormack D. V. , Chow C. T. , Holloway A. F.
Published: April 2010

The RNA polymerase in cells infected with three group I mutants of vesicular stomatitis virus has been examined. Mouse L cells were incubated at the permissive temperature (30 °C) for a few hours after infection to allow the development of secondary transcription. The temperature dependence of the secondary transcription system was determined from the incorporation of labelled uridine, in the presence of cycloheximide. at 30 and at 38 °C, the latter temperature being non-permissive for viral replication. In cells infected with mutants W14, W28, and G11 at a low multiplicity (20 PFU/cell) secondary transcriptase activity was markedly temperature-sensitive after 3 and 5 h of infection at 30 °C. At a high multiplicity of infection (1000 PFU/cell) cells infected with W28 showed considerable RNA synthesis at 38 °C after 3 h at 30 °C. RNA synthesis was also observed in W28-infected cells in which protein synthesis was allowed to continue after the shift from 30 to 38 °C. In the latter two cases the RNA synthesized contained 12–18S species but little or no 30S mRNA.