bluuebunny/crossref_metadata_2025 huggingface dataset:
Degradation of Hydrocarbons by Members of the Genus
Candida
III. Oxidative Intermediates from 1-Hexadecene and 1-Heptadecene by
Candida lipolytica
Authors: Klug M. J. , Markovetz A. J.
Published: January 2020

Candida lipolytica
(Phaff) was grown in a mineral-salts medium amended with either 1-hexadecene or 1-heptadecene as substrate. Intermediates of the same chain length as the substrate were isolated and identified by various analytical procedures. The following intermediates of 16 and 17 carbon atoms were identified: ω-unsaturated acids, ω-unsaturated primary and secondary alcohols, 1,2-epoxides, 1,2-diols, and 2-hydroxy acids. Based on the chemical structure of these compounds, three oxidative mechanisms are proposed for the degradation of long-chain 1-alkenes by this yeast: (i) methyl-group oxidation, (ii) double-bond oxidation, and (iii) subterminal oxidation.
Cholera Toxins: Purification and Preliminary Characterization of Ileal Loop Reactive Type 2 Toxin
Authors: Coleman William H. , Kaur Jasbir , Iwert Marian E. , Kasai George J. , Burrows William
Published: January 2020

Details for the preparation and partial purification of culture supernatant fluids of
Vibrio cholerae
(
V. comma
) 569B which retain rabbit ileal loop fluid-accumulating activity are presented. These preparations were fractionated on Sephadex G-200 and on diethylaminoethyl-Sephadex. On the latter, two fractions were obtained by elution with a linear sodium chloride gradient. The fraction designated “fraction I” retains the toxic activity as demonstrated in the rabbit ileal loop model. Chemical and immunological properties of this active fraction are described.
Immunochemical Analysis of Serologically Active Lipids ofMycoplasma pneumoniae
Authors: Beckman Betsy L. , Kenny George E.
Published: January 2020

The major complement-fixing antigen ofMycoplasma pneumoniaeis found in the lipid fraction of the organism. When the lipids ofM. pneumoniaewere fractionated by column chromatography on silicic acid, serological activity against both rabbit and human immune sera was found in two fractions, B and D. Fraction B, eluted with chloroform–methanol (9:1), was a minor component in terms of total complement-fixing activity and contained a complex of lipids which were detected in the region characteristic of phosphatidic acids by thin-layer chromatography on Silica Gel G. Fraction D, eluted with ethyl acetate–methanol (3.5:2), had approximately the same complement-fixing antigen titer as the original lipid extract and appeared as a “comet-shaped” spot between phosphatidylethanolamine and phosphatidylcholine on Silica Gel G plates charred with sulfuric acid. However, by thin-layer chromatography on Silica Gel H impregnated with sodium tetraborate, it was demonstrated that fraction D did contain multiple components, all but one of which were carbohydrate-containing lipids (giving positive reactions when sprayed with orcinol-sulfuric acid reagent). Fraction D was found to contain glycerol and phosphate in equimolar ratios but did not contain nitrogen. Two sugars were detected which migrated on paper chromatograms with glucose and galactose.
Purification of β-Glucosidase from
Saccharomyces lactis
Strain Y-123
Authors: Marchin George L. , Duerksen Jacob D.
Published: January 2020

Saccharomyces lactis
strain Y-123, a constitutive high producer of β-glucosidase (B
h
), was grown in an enriched medium. β-Glucosidase, extracted most easily by cell autolysis, was purified by successive ammonium sulfate precipitation, ethyl alcohol precipitation, gel filtration, calcium phosphate gel adsorption-elution, and hydroxyapatite column chromatography. The specific activity of the enzyme increased 200-fold during the purification. The electrophoretic and catalytic properties of the enzyme did not change during the procedure. Polyacrylamide gel disc electrophoresis of the partially purified enzyme revealed one major and several minor protein-staining bands. β-Glucosidase activity in the polyacrylamide gel columns was measured directly by assaying sections of columns frozen and sliced immediately after electrophoresis. Most of the activity coincided with the major protein-staining band. Prolonged assay produced minor activity coinciding with the less intense protein bands. Properties of the enzyme suggest that it is a single, unconjugated, intracellular, high molecular weight protein. The purification procedure is applicable to strains of
S. lactis
which possess alleles of the B locus for β-glucosidase synthesis.
Purification of β-Glucosidase from
Saccharomyces lactis
Strains Y-14 and Y-1057A
Authors: Marchin George L. , Duerksen Jacob D.
Published: January 2020

Two strains of
Saccharomyces lactis
(Y-14 and Y-1057A), medium (B
m
) and low (B
1
) constitutive producers of β-glucosidase, were grown in enriched medium. β-Glucosidase was extracted by autolysis and purified by ammonium sulfate precipitation, gel filtration, and calcium phosphate gel adsorption-elution. The kinetics of release, purification, and stability of β-glucosidase from strains Y-14 and Y-1057A were compared with the enzyme from strain Y-123. The ability of glycerol, sorbitol, and mannitol to stabilize the β-glucosidases is presented. A lower molecular weight, labile form of the Y-14 enzyme is demonstrated. Differences in the initial specific activites of β-glucosidase among the three strains are discussed.
Nonrandom Sister Chromatid Segregation and Nuclear Migration in Hyphae of
Aspergillus nidulans
Authors: Rosenberger R. F. , Kessel M.
Published: January 2020

Radioactive conidiospores of
Aspergillus nidulans
were prepared by growing a purine-requiring mutant with tritiated adenine. When these spores germinated in a nonradioactive medium, the dispersion of the original chromosome set could be followed by treating the hyphae with ribonuclease and preparing radioautograms. Germinating spores with four or eight nuclei contained two highly labeled nuclei and two or six nuclei with much less or no radioactivity. Successive mitotic divisions thus distributed the deoxyribonucleic acid (DNA) of the eight spore chromosomes among only two of the progeny nuclei. The two nuclei containing the original chromosome set were not dispersed at random along the linear hypha but were usually located near the growing tip. These results are compatible with the view that chromatids containing DNA strands of identical age segregate as a unit during mitosis. They further indicate that the mechanism which disperses newly formed nuclei in the growing hypha can distinguish between nuclei containing DNA strands of different ages.
Pyrimidine Biosynthesis in
Lactobacillus leichmannii
Authors: Hutson Judith Y. , Downing Mancourt
Published: January 2020

Tracer studies of pyrimidine biosynthesis in
Lactobacillus leichmannii
(ATCC 7830) indicated that, while aspartate is utilized in the usual manner, the guanido carbon of arginine, rather than carbon dioxide, is utilized as a pyrimidine precursor. The guanido carbon of arginine also contributes, to some extent, to the carbon dioxide pool utilized for purine biosynthesis. The enzyme of the first reaction leading from arginine to pyrimidines, arginine deiminase, was investigated in crude bacterial extracts. It was inhibited by thymidylic acid and purine ribonucleotides, and to a lesser extent by purine deoxynucleotides and deoxycytidylic acid. Under the assay conditions employed, a number of nucleotides had no effect on the enzyme activity of the aspartate transcarbamylase of
L. leichmannii
. Growth of the cells in media containing uracil, compared to growth in media without uracil, resulted in a four- to fivefold decrease in the concentrations of aspartate transcar-bamylase and dihydroorotase and a twofold increase in the concentration of arginine deiminase, as estimated from specific enzyme activity in crude extracts of the cells. A small increase in specific enzyme activity of ornithine transcarbamylase and carbamate kinase was also observed in extracts obtained from cells grown on uracil. No appreciable change in concentration of any of the five enzymes studied was detected when the cells were grown in media containing thymidine or guanylic acid. A hypothetical scheme which suggests a relationship between the control of purine and pyrimidine biosynthesis in this bacterium and which is consistent with the experimental results obtained is presented.
Curing of a Sporulation Mutant and Antibiotic Activity of
Bacillus subtilis
Authors: Schmitt Rüdiger , Freese Ernst
Published: January 2020

Sporulation mutants of
Bacillus subtilis
, blocked either in the citric acid cycle or in another pathway necessary for uracil incorporation during the developmental period, were tested for their sporulation response to different carbon sources. All of the citric acid cycle mutants and all but one of the other mutants failed to respond. The one phenotypically curable mutant, 60764, responded to most metabolizable carboxylic acids, such as acetate and fatty acids, and to some other carbon sources. For an optimal response, it was necessary to add the compound at a certain concentration and time (0.08
m
for acetate, when the extinction of the culture at 600 nm was 1). A liquid medium was devised in which an appreciable amount of antibiotic activity against
Staphylococcus aureus
was produced by our standard strain 60015. The mutant 60764 produced, even in the presence of palmitate, 20 times less antibiotic and sporulated more slowly than 60015. The antibiotic activity in both strains consisted of three major and several minor molecular species, as detected by thin-layer chromatography. When purified antibiotic was added to an exponentially growing culture of our standard strain of
B. subtilis
, lysis ensued, the extent of which increased with the concentration of the antibiotic added; later, resistant bacteria grew up. Three mutants unable to produce antibiotic activity were isolated and found to be deficient in sporulation. These findings show the close correlation between sporulation and antibiotic activity, but they do not prove that antibiotic activity is needed for sporulation.
Characterization of Mutants with Single and Multiple Defects in the Tryptophan Biosynthetic Pathway in
Bacillus subtilis
Authors: Whitt Dixie D. , Carlton Bruce C.
Published: January 2020

Sixty-five tryptophan auxotrophs which map in a cluster on the genome of
Bacillus subtilis
were characterized on the basis of (i) growth response, (ii) accumulation of intermediate compounds, and (iii) determination of enzymatic defects. They could be placed into six phenotypic classes. Certain of the mutants exhibited pleiotropic effects on more than one enzymatic activity in a manner different from those effects reported for the tryptophan pathway in other organisms. Invariably, mutations in the second gene, that coding for phosphoribosyl transferase activity, were found to lack the indoleglycerol phosphate synthase activity specified by the third gene in the cluster; however, this polarity did not extend to genes more distal in the cluster. Furthermore, mutations in the gene which codes for phosphoribosyl-anthranilate isomerase not only led to a loss of this enzyme but also to a loss of phosphoribosyl transferase and indoleglycerol phosphate synthase. In contrast, mutations in either of the loci coding for these latter functions had no apparent effect on isomerase activity. No polarity of the conventional type was found, e.g., none of the mutations in any gene led to polarized effects on the levels of the enzymes specified by the other genes of the cluster. These observations indicated a possible in vivo aggregation involving the transferase, isomerase, and synthase enzymes, with the isomerase acting as the “key” enzyme in the aggregate.
Synthesis of 7-Oxo-8-Aminopelargonic Acid, a Biotin Vitamer, in Cell-free Extracts of
Escherichia coli
Biotin Auxotrophs
Authors: Eisenberg M. A. , Star C.
Published: January 2020

The enzymatic synthesis of 7-oxo-8-aminopelargonic acid (7-KAP) from pimelyl-coenzyme A and
l
-alanine was demonstrated in cell-free extracts of a biotin mutant of
Escherichia coli
K-12 which excretes only 7-KAP into the growth medium. This biotin vitamer was identified by its chromatographic and electrophoretic properties. The enzyme (7-KAP synthetase) was repressed when the organism was grown in biotin concentrations greater than 0.2 ng/ml. The parent strain and members of other mutant groups that excrete 7-KAP, in addition to other vitamers, also exhibited synthetase activity. A mutant group that failed to excrete 7-KAP was further sub-divided into three groups, one of which lacked synthetase activity. These results are discussed in relation to a previously proposed scheme for biotin biosynthesis in which the formation of 7-KAP is considered the point of entry for pimelic acid into the biotin pathway.
Relationship Between Sexuality and Carotene Synthesis in
Blakeslea trispora
Authors: Van Den Ende H.
Published: January 2020

When stimulated by equivalent amounts of progametangia-inducing hormones, cultures of the
minus
mating type of
Blakeslea trispora
produce about the same quantities of carotenoids as mated cultures of the fungus, which suggests that the stimulation of carotene synthesis during the sexual activity of mated cultures is the result of hormonal action. These hormones were isolated and purified. From spectroscopic analysis of purified samples, it appears that the hormones are identical with trisporic acids B and C. When both mating types of
B. trispora
were cultivated in one vessel but were kept apart by membrane filters, the formation of sex hormones was not inhibited. Physical contact between the mating types is obviously not required for the induction of sexual activity. The sex hormones also formed in combined cultures of
B. trispora-plus
and
Zygorhynchus moelleri
(a homothallic species), but not in combined cultures of
B. trispora-minus
and
Z. moelleri
. This is evidence for the hypothesis that the hormones are produced by
B. trispora-plus
only.
Molecular and Structural Damage toEscherichia coliProduced by Antibody, Complement, and Lysozyme Systems
Authors: Wilson Lawrence A. , Spitznagel John K.
Published: January 2020

The antibacterial action of antibody (normal and hyperimmune), complement, and lysozyme has been studied by correlating the ultrastructural and biochemical changes that they cause in smoothEscherichia coli. Both normal and hyperimmune antibody, in the absence of lysozyme, produced complement-dependent release, into the suspending medium, of 63 to 72% of the32P-labeled phospholipid and 74 to 85% of the small molecular bacterial constituents. Macromolecular nucleic acid labeled with32P was not released. By phase microscopy, these cells appeared as bacilli but their ultrastructure showed general swelling, with smoothing of the normally wrinkled outer cell wall layers. Cytoplasmic membranes were damaged and the internal cell structure was disorganized. Membranous spherules, apparently from the outermost putatively lipopolysaccharide cell layer, were released into the medium. When lysozyme was added to antibody and complement,32P-labeled macromolecular constituents were released from the cells. Damage to ultrastructure then included loss of cell wall rigidity, cell wall breakage, and some spheroplast formation. Characteristic fibrillar fragmentation was seen in cell wall mucopeptide layers. The relationships between antibody-complement dependent release of bacterial phospholipid, loss of selective cell permeability, and increase in sensitivity to lysozyme are discussed.
Ultrastructural Features of Host-Parasite Relationship in Oral Candidiasis
Authors: Montes Leopoldo F. , Wilborn Walter H.
Published: January 2020

In oral candidiasis, many keratinized epithelial cells and cells of
Candida albicans
are shed. Scales from patients with oral candidiasis were used for electron microscopic study of the epithelial-fungal relationship. Scales, scraped from the tongue and oral mucosa, were fixed for fungi. Electron microscopic observations showed cells of
C. albicans
outside, penetrating, or within the epithelial cells. Extracellular fungi possessed a floccular material adherent to the outer surface of the cell wall. Intracellular fungi lacked the floccular material which appeared to detach as fungi invaded the epithelial cells. Large vacuoles, which sometimes contained myelin figures, occupied the cytoplasm of fungal cells. Epithelial cells frequently contained several fungi. Discontinuous plasma membranes marked sites of fungal entry. Cytoplasmic areas devoid of fungi showed many tonofibrils, but the cytoplasm adjacent to fungi often lacked tonofibrils. Micrographs suggested that fungal cells lysed the tonofibrils. Bacteria were abundant in the scrapings, but always occupied an extracellular position.
Effect of Penicillin on the Multiplication of Meningopneumonitis Organisms (
Chlamydia psittaci
)
Authors: Tamura Akira , Manire G. P.
Published: January 2020

Although formation of infectious particles of meningopneumonitis organism in L cells was completely inhibited by 1 or more units of penicillin per ml, multiplication of reticulate bodies was observed, by light microscopy, in the presence of 200 units of penicillin per ml in stained smears of infected cells. When reticulate bodies were purified from cultures containing penicillin after 18, 30, and 45 hr of incubation, continuously increasing yields were obtained. When penicillin was added to infected cultures 0 to 15 hr after infection, no increase in infectivity was observed at 40 hr, but when antibiotic was added between 20 and 35 hr, partial synthesis of infectious particles was observed at 40 hr. On the other hand, removal of penicillin from an infected culture before 15 hr after infection did not affect the final yields of infectivity when assayed at 40 hr, but elimination of penicillin after 20 hr resulted in a decrease in infectivity. In suspensions of
32
P-labeled purified reticulate bodies grown in cultures containing penicillin and harvested 18 and 40 hr after infection, the
32
P distributions obtained by acid fractionation were similar to those of reticulate bodies from penicillin-free cultures. Cell membranes of reticulate bodies were also prepared from 40-hr cultures with penicillin. The size and shape of purified membranes, as seen by electron microscopy, and their amino acid compositions were similar to membranes prepared from reticulate bodies grown without penicillin, except that very small structures were observed in membranes from cultures containing penicillin. These results indicated that penicillin does not inhibit reproduction of reticulate bodies and formation of their cell membranes, but does inhibit the formation of elementary body cell envelopes.
Heterogeneity of Antibody Response toSalmonellaLipopolysaccharide Measured by Passive Hemagglutination and Hemolysis in Mice
Authors: Ransom John P. , Larson Charles , Gorman Joan M. , Tulve Sibylle
Published: January 2020

The complement-requiring passive hemolysis test withSalmonella typhimuriumlipopolysaccharide-coated sheep erythrocytes is more sensitive for antibodies directed against the lipopolysaccharide than is the passive hemagglutination test. The hemagglutinating and hemolyzing antibodies produced in Swiss mice by hyperimmunization, either with or without Freund's adjuvant, were distributed in both the light and heavy fractions isolated by sucrose density gradient fractionation and gel filtration. IgM fractions, whether tested by hemagglutination or hemolysis, were sensitive to 2-mercaptoethanol (0.15m). On the other hand, IgG hemolytic antibodies were more sensitive to 2-mercaptoethanol than were IgG hemagglutinating antibodies. The resistance of IgG hemagglutinating activity amounted to about 72 to 95% of the total IgG recovered, whereas the resistant portion of the IgG hemolytic activity was approximately 40 to 53%. It is suggested that, although mercaptoethanol sensitivity is not a definitive test for IgM antibody, its use in connection with the hemagglutination test gives at least an approximation of the IgG antibody, whereas the hemolysis test gives a better approximation of maximal measurable antibody againstSalmonellalipopolysaccharides.
Physiology and Nutrition of
Lampropedia hyalina
Authors: Puttlitz Donald H. , Seeley H. W.
Published: January 2020

A detailed study of the physiology and nutrition of
Lampropedia hyalina
revealed that it is an aerobic, cytochrome-containing chemoheterotroph which is limited in its energy sources to a few intermediates (and close derivatives) of the Krebs cycle. Reducing compounds at low levels are potent growth inhibitors. The microbe has no photosynthetic ability (despite its previous taxonomic position with the sulfur purple bacteria). The results of a general investigation of its physiology are reported. Added biotin and thiamine are needed for growth in defined media; pantothenate is strongly stimulatory. Alanine, arginine, and tyrosine, as well as NH
4
Cl, serve as sole nitrogen sources. A unique motion exhibited by cells of a rapidly growing culture is described. Aspects of its metabolism of poly-β-hydroxybutyrate and limiting aspects of its physiology as related to its ecology are discussed.
Reactivation of Ribonucleic Acid and Protein Synthesis During Germination of
Blastocladiella
Zoospores and the Role of the Ribosomal Nuclear Cap
Authors: Lovett James S.
Published: January 2020

Freshly harvested zoospores of
Blastocladiella emersonii
begin to germinate about 15 min after inoculation into a defined growth medium at a density of 10
6
zoospores per ml. Flagellum retraction accompanies encystment, and dispersal of the ribosomal nuclear cap takes place shortly thereafter. The primary rhizoid begins to emerge at 25 to 30 min and starts to branch at ca. 60 min. The first nuclear division occurs between 120 and 190 min. The dry weight per cell increases linearly after 60 min, whereas the deoxyribonucleic acid per cell doubles between 120 and 240 min. A linear increase in total ribonucleic acid (RNA) is detectable beginning at 40 to 45 min, and in total protein beginning at 80 min; neither process is interrupted during nuclear division. Encystment and nuclear cap disorganization are associated with a sharp rise in the rates of precursor incorporation into RNA and protein. Cycloheximide at 20 μg/ml prevents leucine incorporation at all stages and inhibits development beyond the earliest encystment stage. Actinomycin D at 25 μg to 50 μg/ml prevents uracil incorporation, but it has no effect on leucine incorporation or development until 40 to 45 min. At the latter stage, actinomycin D causes a sharp developmental arrest and begins to inhibit leucine incorporation. It is concluded that early protein synthesis must occur on the ribosomes formed during the prior growth phase and conserved through the zoospore stage in the nuclear cap. The results further indicate that this synthesis is dependent upon messenger RNA already present in the zoospore before germination.
Selection of a Mutant ofEscherichia coliWhich Has High Mutation Rates
Authors: Helling Robert B.
Published: January 2020

A mutation which causes high mutation rates in all other loci tested was induced with nitrosoguanidine and was selected through the ability of the progeny of such mutant cells to mutate to streptomycin resistance at a higher rate than the wild-type cells. This mutation (mut-2) and the Treffers' mutation (mutT1) mapped at approximately the same position to the right ofleu. Specificity studies showed that the two mutations differ in rates of mutation produced.
Production of a Capsular Polysaccharide by a Marine Filamentous Fungus
Authors: Szaniszlo Paul J. , Wirsen Carl , Mitchell Ralph
Published: January 2020

The spent seawater medium of 4-day-old-cultures of the filamentous marine fungus
Leptosphaeria albopunctata
had a high viscosity after the fungus was collected by high-speed centrifugation. Microscopic examination of uncentrifuged mycelium suspended in India ink revealed that the viscosity resulted from capsular material. These capsules became disassociated from the mycelium during centrifugation. Precipitation of the medium of centrifuged cultures with 95% ethyl alcohol yielded a highly anthrone-positive polysaccharide material, composed of large amounts of glucose and minute amounts of mannose. Time course studies of the nutritional requirements for capsular polysaccharide production revealed that the capsular material was produced in large amounts, and on a wide variety of sugars, during the period of rapid growth, but was quickly degraded and presumably remetabolized in older cultures. The amount of capsular material produced was enhanced by NaCl concentrations above that of artificial seawater, and KCl could be substituted for NaCl. The salts MgCl
2
and CaCl
2
were also required for capsule production by
L. albopunctata
, although growth was obtained in cultures without added amounts of these constituents. The possible role of these salts in the metabolism of the fungus is discussed.
Lymphocytosis and Histamine Sensitization of Mice by Fractions from
Bordetella pertussis
Authors: Clausen C. , Munoz J. , Bergman R. K.
Published: January 2020

Administration of
Bordetella pertussis
cell extracts induced in mice hypersensitivity to histamine, as well as pronounced leukocytosis and hypoglycemia. The leukocytosis was mainly caused by an increase in the small lymphocytes in the circulating blood, and it was most pronounced 3 to 4 days after injection of
B. pertussis
extracts. Rabbit antimouse lymphocyte serum produced a decrease in the lymphocyte count in normal mice, as well as in mice treated with
B. pertussis
extracts. This depression in lymphocytes was observed whether the antilymphocyte serum was given 1 day or 2 days after the administration of
B. pertussis
extracts. The increased histamine sensitivity and hypoglycemia of mice treated with
B. pertussis
extract were not affected by treatment with antilymphocyte serum, although a marked lymphopenia was present. These observations indicate that the three phenomena observed in pertussis-treated mice are independent of each other.
l
-Serine Deaminase of
Escherichia coli
Authors: Alföldi Lajos , Raskó István , Kerekes Erzsébet
Published: January 2020

The native
l
-serine deaminase (
l
-serine hydrolyase, deaminating, EC 4.2.1.13) of
Escherichia coli
K-12, which seems to be a very labile protein, is rather stable in concentrated solution. Dilution rapidly inactivates it, but in the presence of a saturating concentration of
l
-serine the molecule is protected from inactivation. It is a very specific enzyme;
l
-serine is the sole substrate with a
K
m
value of 6.60 × 10
−3
m. d
-Serine and
l
-cysteine are competitive inhibitors. Substrate saturation curves of the native enzyme show sigmoid shape, whereas the enzyme liberated from the bacteria in the presence of
l
-serine exhibits normal Michaelis-Menten kinetics.
Ribonucleic Acid Synthesis and Glutamate Excretion in
Escherichia coli
Authors: Broda Paul
Published: January 2020

Cultures of
Escherichia coli
excreted glutamate into the medium when protein synthesis was blocked in RC
rel
strains or when it was blocked with chloramphenicol in either RC
str
or RC
rel
strains. Both of these conditions resulted in continued ribonucleic acid (RNA) synthesis in the absence of protein synthesis. Glutamate was also excreted by both RC
str
and RC
rel
strains when RNA synthesis was inhibited by uracil starvation or by treatment with actinomycin D. It is proposed that, in each of these cases, glutamate excretion resulted from an increase in the permeability of the cell membrane.
Antibody Response to
Staphylococcus aureus
in Rabbits: Sequence of Immunoglobulin Synthesis and Its Correlation with Passive Protection in Mice
Authors: Yoshida Kosaku , Ekstedt Richard D.
Published: January 2020

Antibody in hyperimmune rabbit antisera specific for
Staphylococcus aureus
teichoic acid was shown to be associated with the IgM fraction. Treatment of such sera with mercaptoethanol destroyed its activity in passive mouse protection tests, whereas absorption with antirabbit IgG had no effect. Antibody response in normal rabbits immunized by a single or by three daily injections of a killed vaccine of
S. aureus
was followed by a sensitive passive hemagglutination test. Antibody detected during the “primary” response was completely susceptible to reduction with mercaptoethanol. Most of the antibody detected after a secondary antigenic stimulation at 10 weeks was also susceptible to mercaptoethanol. The antibody titers correlated well with mouse protective activity, and this activity of the serum was also shown to be associated with the IgM fraction.
Infectious Drug Resistance Among Clinically Isolated
Escherichia coli
Authors: Gunter Ann C. , Feary Thomas W.
Published: January 2020

Of 398 strains of clinically isolated
Escherichia coli
from three Birmingham, Alabama, hospitals, 38% were found to be resistant to one or more drugs tested. Fifty-seven per cent of the resistant strains transferred all or a part of their resistance pattern to sensitive cells during mixed cultivation. Of the 152 resistant strains, 29.1% were singly resistant, and 70.5% were resistant to more than one drug. Of the multiply resistant strains, 61% transferred all or a part of their pattern. Strains isolated from Veterans Hospital patients demonstrated higher percentages of resistance than strains isolated from Children's Hospital patients. An extremely low incidence of infective drug resistance was noted among
E. coli
isolated from the stools of healthy hospital employees.
In Vivo Inactivation of Lysozyme by Ozone
Authors: Holzman R. S. , Gardner D. E. , Coffin D. L.
Published: January 2020

Bronchial mucus contains large quantities of the antibacterial enzyme lysozyme. Acutely exposing mice or rabbits to ozone reduced the amount of active lysozyme obtainable by bronchopulmonary lavage. The effect was proportional to ozone concentration, as well as to duration of exposure. Enzyme activity returned to normal levels during the 12 hr following exposure. Ozone (5 μliters/liter; 5 parts per million) for 3 hr reduced lysozyme levels approximately 30%. Studies of the release of lysozyme by alveolar cells support the theory that loss of activity is due to in vivo oxidation of lysozyme.
Influence of Gas Environment on Catabolic Activities and on Reoxidation of Reduced Nicotinamide Adenine Dinucleotide Phosphate in
Chlamydia
Authors: Weiss E. , Neptune E. M. , Gaugler R. W.
Published: January 2020

We investigated the effect of the gas environment on the enzymatic reactions of intact isolated cells of the agents of trachoma and of meningopneumonitis of the host-dependent genus
Chlamydia
. In comparison with the reactions taking place in a gas phase of air, O
2
depressed CO
2
production from pyruvate and glutamate by trachoma and from glutamate by meningopneumonitis. O
2
enhanced the degradation of pyruvate by meningopneumonitis, but this effect was due to increased H
2
O
2
, and was reversed by added catalase. Both dehydrogenation of α-ketoglutarate and was reversed by added catalase. Dehydrogenation of α-ketoglutarate by both agents and production of CO
2
from C
1
of glucose-6-phosphate were stimulated by O
2
and depressed in N
2
. The latter activity was stimulated in air, O
2
, and N
2
by nicotinamide adenine dinucleotide phosphate (NADP) in relation to the amount added, and also in air or O
2
, but not in N
2
, by moderate amounts of NADP and an excess of oxidized glutathione with concomitant formation of H
2
O
2
. A small but significant amount of O
2
was consumed during the course of these reactions. It is suggested that glutathione reductase activity can occur only when accompanied by an oxidative reaction, and that this close link between the two reactions represents a mechanism of electron transport which transfers hydrogen to molecular O
2
.
Specificity and Control of Choline–
O
-Sulfate Transport in Filamentous Fungi
Authors: Bellenger Nicole , Nissen Per , Wood Trudy C. , Segel Irwin H.
Published: January 2020

Choline-
O
-sulfate uptake by
Penicillium notatum
showed the following characteristics. (i) Transport was mediated by a permease which is highly specific for choline-
O
-sulfate. No significant inhibition of transport was caused by choline, choline-
O
-phosphate, acetylcholine, ethanolamine-
O
-phosphate, ethanolamine-
O
-sulfate, methanesulfonyl choline, 2-aminoethane thiosulfate, or the monomethyl or dimethyl analogues of choline-
O
-sulfate. Similarly, no significant inhibition was caused by any common sulfur amino acid or inorganic sulfur compound. Mutants lacking the inorganic sulfate permease possessed the choline-
O
-sulfate permease at wild-type levels. (ii) Choline-
O
-sulfate transport obeyed saturation kinetics (
K
m
= 10
−4
to 3 × 10
−4
m
;
V
max
= 1 to 6 μmoles per g per min). The kinetics of transport between 10
−9
and 10
−1
m
external choline-
O
-sulfate showed that only one saturable mechanism is present. (iii) Transport was sensitive to 2,4-dinitrophenol, azide,
N
-ethylmaleimide,
p
-chloromercuribenzoate, and cyanide. Ouabain, phloridzin, and eserine had no effect. (iv) Transport was
p
H-dependent with an optimum at
p
H 6. Variations in the ionic strength of the incubation medium had no effect. (v) Transport was temperature-dependent with a Q
10
of greater than 2 between 3 and 40 C. Transport decreased rapidly above 40 C. (vi) Ethylenediaminetetraacetate (sodium salts,
p
H 6) had no effect, nor was there any stimulation by metal or nonmetal ions. Cu
++
, Ag
+
, and Hg
++
were inhibitory. (vii) The initial rate at which the ester is transported was independent of intracellular hydrolysis. After long periods of incubation (> 10 min), a significant proportion of the transported choline-
O
-sulfate was hydrolyzed intracellulary. In the presence of 5 × 10
−3
m
external choline-
O
-sulfate, the mycelia accumulated choline-
O
-sulfate to an apparent intracellular concentration of 0.075
m
by 3 hr. Transport was unidirectional. No efflux or exchange of
35
S-choline-
O
-sulfate was observed when preloaded mycelia were suspended in buffer alone or in buffer containing a large excess of unlabeled choline-
O
-sulfate. (viii) The specific transport activity of the mycelium depended on the sulfur source used for growth. (ix) Sulfur starvation of sulfur-sufficient mycelium resulted in an increase in the specific transport activity of the mycelium. This increase was prevented by cycloheximide, occurred only when a metabolizable carbon source was present, and resulted from an increase in the
V
max
of the permease, rather than from a decrease in
K
m
. The increase could be partially reversed by refeeding the mycelia with unlabeled choline-
O
-sulfate, sulfide, sulfite,
l
-homocysteine,
l
-cysteine, or compounds easily converted to cysteine. The results strongly suggested that the choline-
O
-sulfate permease is regulated primarily by repression-derepression, but that intracellular choline-
O
-sulfate and cysteine can act as feedback inhibitors.
Control of Dimorphism in
Mucor
by Hexoses: Inhibition of Hyphal Morphogenesis
Authors: Bartnicki-Garcia S.
Published: January 2020

In anaerobic cultures of
Mucor rouxii
, morphogenesis was strongly dependent on hexose concentration as well as
p
CO
2
. At low levels of hexose or CO
2
, or both, hyphal development occurred; at high levels, the fungus developed as yeast cells. Other dimorphic strains of
Mucor
responded similarly to hexose and CO
2
but differred in their relative sensitivity to these agents. Glucose was the most effective hexose in eliciting yeast development of
M. rouxii
; fructose and mannose were next; and galactose was last. The fungus may be grown into shapes covering its entire dimorphic spectrum simply by manipulating the hexose concentration of the medium. Thus, at 0.01% glucose, hyphae were exceedingly long and narrow; at higher sugar concentrations, the hyphae became progressively shorter and wider; finally, at about 8% glucose, almost all cells and their progeny were isodiametric (spherical budding cells). Such yeast development occurred without a manifested requirement for exogenous CO
2
. The stimulation of yeast development by hexose is not an artifact due to increased production of metabolic CO
2
(hyphae or yeast cells released metabolic CO
2
at similar rates). Presumably, the effect was caused by some other hexose catabolite which interfered with hyphal morphogenesis (apical growth); deprived of its polarity, the fungus grew into spherical yeastlike shapes. Although 10% glucose inhibited the development of hyphae from germinating spores, it did not prevent the elongation of preformed hyphae. This suggests that hexose inhibits hyphal morphogenesis not by blocking the operation of the enzyme complex responsible for apical growth but by preventing its initiation; such inhibition may be regarded as a repression of hyphal morphogenesis.
Molar Growth Yields as Evidence for Oxidative Phosphorylation in
Streptococcus faecalis
Strain 10C1
Authors: Smalley A. J. , Jahrling P. , Van Demark P. J.
Published: January 2020

During the aerobic growth of
Streptococcus faecalis
strain 10C1, with limiting levels of glucose as the substrate, a molar growth yield (Y) of 58.2 g (dry weight) per mole of glucose was obtained. Under these conditions of growth, glucose was dissimilated primarily to acetate and CO
2
. The incorporation of
14
C-glucose into cell material was no greater under aerobic conditions than during anaerobic growth. Assuming an adenosine triphosphate coefficient of 10.5, the aerobic Y cannot be explained solely on the basis of substrate phosphorylation and would appear to substantiate previous enzymatic evidence for oxidative phosphorylation in this cytochromeless species. With mannitol as the substrate, an aerobic Y of 64.6 was obtained. Extracts of mannitol-grown cells contained a nicotinamide adenine dinucleotide (NAD)-linked mannitol-1-phosphate (M-1-P) dehydrogenase. The difference in aerobic Y values with mannitol and glucose as substrates would indicate that the in vivo P/O ratio from the oxidation of reduced NAD generated by the oxidation of M-1-P approximates 0.6. The Y values with pyruvate and glycerol as substrates under aerobic conditions were 15.5 and 24.7, respectively.
Morphology, Physiology, and Serology of a
Pasteurella
Species Pathogenic for White Perch (
Roccus americanus
)
Authors: Janssen W. A. , Surgalla M. J.
Published: January 2020

The
Pasteurella
species implicated as the etiologic agent of a massive white perch mortality in the Chesapeake Bay and first described by S. F. Snieszko et al. has been characterized further in our laboratory. The general morphology and physiology of this organism is similar to that of the pasteurellae and several known fish pathogens. There are enough dissimilarities, however, to rule out its identification with any established species. The organism is obligately halophilic and grows in a temperature range between 17 and 31 C on ordinary media containing 1% NaCl. It has a relatively narrow range of
p
H, temperature, and salinity tolerance, and a very short survival time in spent media or brackish water, in contrast to
Pasteurella pestis
and
P. pseudotuberculosis
. Serological tests also indicate that this organism is distinct from other species which it resembles. On the basis of classic morphological and physiological criteria, this organism fits best in the genus
Pasteurella
; the species name
piscicida
(L. noun
piscis
, a fish; L.v.L.adj. suffix-
cidus
, to kill; M.L. noun
piscicida
, fish killer) is proposed.
Fermentation of Ornithine by
Clostridium sticklandii
Authors: Dyer John K. , Costilow Ralph N.
Published: January 2020

Resting cells of
Clostridium sticklandii
fermented
l
-ornithine as a single substrate by a coupled oxidation-reduction with proline as the electron acceptor. The products of the fermentation of ornithine alone were ammonia, alanine, acetate, and δ-aminovalerate, in order of concentration. Traces of CO
2
, butyrate, and proline were also found. When an equimolar amount of proline was added along with ornithine, very little δ-aminovalerate was produced from the ornithine, but essentially all of the proline was reduced to this compound. The ratios of the other primary products were changed by the addition of proline. The primary products from ornithine fermented in the presence of proline were acetate, ammonia, alanine, and CO
2
, in order of concentration. Studies with
dl
-ornithine-
1
-
14
C
,
dl
-ornithine-
2
-
14
C
, and
dl
-ornithine-
5
-
14
C
demonstrated that the primary cleavage of this amino acid occurred between carbons 3 and 4. A high percentage of the isotope from carbons 1 and 2 was found in alanine, and most of that from carbon 5 was found in volatile acid. The CO
2
formed was derived from the carboxyl carbon. All of the radioactivity from the fermentation of
dl
-alanine-
1
-
14
C
was found in
14
CO
2
. The alanine from ornithine was oxidized by
d
-amino acid oxidase to the same extent as
dl
-alanine, indicating that it was
dl
-α-alanine. Preliminary experiments with cell extracts indicated proline is an intermediate in the reduction of ornithine to δ-aminovaleric acid.
Cellular Localization of Acetyl-Coenzyme A Synthetase in Yeast
Authors: Klein Harold P. , Jahnke Linda
Published: January 2020

In cells of
Saccharomyces cerevisiae
grown with glucose in standing cultures, the microsomal fraction had the highest specific activity for acetyl-coenzyme A synthetase and contained the greatest fraction of the total activity regardless of when the cells were harvested during growth. The addition of acetate did not affect the distribution of the enzyme, nor did subsequent aeration of such cells in phosphate buffer even in the presence of glucose, acetate, or succinate. In cells grown aerobically, however, the microsomal fraction had the highest specific activity and the greatest fraction of the total activity only until the cells reached the stationary phase. After this time, most of the activity was associated with the mitochondrial fraction. Finally, 3 or 4 days after inoculation, this fraction appeared to lose most of the enzyme to the microsomal and soluble fractions. Chloramphenicol, at concentrations that interfered with respiration but not with fermentation, prevented the association of acetyl-coenzyme A synthetase with the mitochondrial fraction in aerated cells, but it did not appreciably affect the large increases in enzyme activity observed during aerobic incubation. Cells grown with glucose under strict anaerobic conditions contained barely detectable amounts of acetyl-coenzyme A synthetase.
Common Element in the Repression Control of Enzymes of Histidine and Aromatic Amino Acid Biosynthesis in
Bacillus subtilus
Authors: Chapman Linda F. , Nester Eugene W.
Published: January 2020

Single-step mutants of
Bacillus subtilis
derepressed for enzymes of both aromatic amino acid and histidine biosynthesis were isolated. These mutants occur at a frequency of 10
−6
per cell per generation. All histidine enzymes as well as all enzymes of aromatic acid synthesis which were examined are maximally derepressed. This level cannot be repressed by growth on either histidine or tyrosine. Some of the structural genes which specify the derepressed enzymes are linked to the aromatic cluster; others are unlinked. The significance of these nonrepressible strains is discussed in terms of the mechanism of repression.
Temperature-sensitive Mutants of Yeast Exhibiting a Rapid Inhibition of Protein Synthesis
Authors: Hartwell Leland H. , McLaughlin Calvin S.
Published: January 2020

Certain temperature-sensitive (
ts
−
) mutants of yeast which cannot be corrected by nutritional supplementation exhibited a rapid cessation of protein synthesis after a shift to the restrictive temperature. Genetic and biochemical tests permitted a division of these mutants into four classes. This division was based upon genetic complementation patterns among the mutants and an investigation of glucose incorporation into macromolecules and polyribosome content in the mutants after a shift to the restrictive temperature. A study of these parameters in the parent strain (
ts
+
) in the presence of certain well-characterized inhibitors allowed a tentative identification of the biochemical defects in each of the four classes. The properties of the mutants in class IA were consistent with the hypothesis that they result from a defect in the initiation of polypeptide chains or in ribonucleic acid synthesis; mutants in class IB from a defect in the elongation of polypeptide chains; mutants in class IIA from a defect in energy metabolism; and mutants in class IIB from a lesion affecting membrane function.
Properties of Germinating Spores ofDictyostelium discoideum
Authors: Cotter David A. , Raper Kenneth B.
Published: January 2020

The process of spore germination inDictyostelium discoideumconsists of three sequential stages: activation of dormant spores, swelling of activated spores, and emergence of myxamoebae from swollen spores. Dormant and activated spores are resistant to heating, freezing, or drying. Drying and freezing, moreover, may maintain the activated state until the spores are returned to normal conditions. Low temperature incubation after heat shockorthe presence of an autoinhibitor will return activated spores to the dormant state. The entire spore germination process is aerobic, being inhibited at any point by oxygen deprivation or respiratory poisons. Each spore of this social organism appears to germinate at its own rate and independent of the other spores in the suspension.
Purine Ribonucleosidase
g
from
Aspergillus foetidus
Authors: Reese Elwyn T. , Maguire Anne H.
Published: January 2020

Nucleosidase
g
was prepared by growing
Aspergillus foetidus
on bran, and was purified by passage through a diethylaminoethyl-Sephadex column. The enzyme acted on the purine ribosides (except xanthosine) and on their 5′-phosphates. Action on the latter was a good means for preparing ribose-5-phosphate.
Interaction of theexrandlonGenes inEscherichia coli
Authors: Donch John , Green Michael H. L. , Greenberg Joseph
Published: January 2020

Strains ofEscherichia colicarrying the genelontypically produced excess capsular polysaccharide, and were sensitive to ultraviolet light (UV) irradiation, thymine starvation, and nalidixic acid, forming long filaments after these treatments. Sensitivity was reduced by a number of posttreatments. In the presence of a second UV sensitivity gene,exr, some of these properties were suppressed: long filaments were not formed, the effect oflonon UV and nalidixic acid sensitivity was greatly reduced, and irradiation posttreatments gave an enhancement of survival characteristic ofexrrather thanlonstrains. Production of capsular polysaccharide was not affected by theexrgene.
Genetic and Enzymatic Experiments Relating to the Tertiary Structure of β-Galactosidase
Authors: Langridge J.
Published: January 2020

Fifty-six amber mutations of the β-galactosidase gene of
Escherichia coli
were suppressed by crossing into a stock containing the
supD
suppressor gene. The resultant enzymes, differing only in the position of the inserted serine, were tested for stability at 57 C. Most of the suppressed enzymes were either as stable to heat as the normal enzyme or very unstable. Tests of enzymes produced by the action of other suppressors showed that the degree of stability was characteristic of a particular position in the polypeptide chain of the amino acid substitution and independent of the amino acid inserted. The mutations were placed in linear order in the gene by deletion mapping and three-point linkage tests. The consequent order of the serine substitutions disclosed an alternating pattern of stable and unstable regions over the amino-terminal two-thirds of the enzyme; the carboxy-terminal third of the enzyme was generally unstable. Considerations of coding relations and enzyme structure suggested that serine and glutamine suppression usually result in a change in the hydrophilic nature of the side chains on the outside of the enzyme molecule. It was shown that the potentially unstable regions of the enzyme are probably not indicative of stretches of α-helix or of sites of association. The apparent position of the substrate binding sites was correlated with the location of some of the potentially unstable regions, which may mark the parts of the polypeptide chain in proximity with the substrate.