bluuebunny/crossref_metadata_2025 huggingface dataset:
Glutamate Transport in
Escherichia coli
K-12: Nonidentity of Carriers Mediating Entry and Exit
Authors: Halpern Y. S. , Barash H. , Druck Karnina
Published: January 2020

The exit of glutamate from
Escherichia coli
K-12 cells preloaded with the radioactive amino acid and its relation to the reaction of entry were studied. Experiments with cells preloaded to different intracellular concentrations of radioactive glutamate confirmed our earlier conclusion that glutamate exit was a first-order reaction.
l
-Glutamate, competitive inhibitors of glutamate uptake (
d
-glutamate and
l
-glutamate-γ-methyl ester), noncompetitive inhibitors of glutamate uptake (
l
-serine and
l
-alanine), and the energy poison NaN
3
all accelerated glutamate exit 2.8-fold. No additive effect was observed in the presence of NaN
3
together with
l
-glutamate. Preloading with cold
l
-glutamate did not increase the rate of uptake of radioactive glutamate. It is concluded that the acceleration of glutamate exit in the presence of
l
-glutamate in the medium is not due to exchange diffusion and that
l
-glutamate and azide affect exit indirectly by preventing recapture. Sucrose, 25%, slowed down glutamate exit by a factor of about 4.7 and increased the steady-state level of glutamate accumulation to about the same extent. Increasing the intracellular K
+
concentration enhanced glutamate uptake but did not affect the half-time of exit. It is concluded that separate carriers are most probably involved in mediating the entry and exit reactions.
Cell Wall of
Mycobacterium lepraemurium
Strain Hawaii
Authors: Azuma Ichiro , Yamamura Yuichi , Tanaka Yoshinori , Kohsaka Kenji , Mori Tatsuo , Itoh Tonetaro
Published: January 2020

The chemical properties of the cell wall of
Mycobacterium lepraemurium
strain Hawaii were investigated. Five subunits of the cell wall, arabinose mycolate, mycolic acids, tetrapeptide (Ala-Gln-diaminopimelic acid-Ala), disaccharide (
N
-acetylglucosaminyl-β-1,4-
N
-glycolylmuramic acid), and arabinogalactan, were obtained, and their chemical structures were identified.
Differential Heat Stabilities of
Bacillus
Amylases
Authors: Bliesmer Barry O. , Hartman Paul A.
Published: January 2020

Seventeen cultures representing eight strains of
Bacillus coagulans
and twelve cultures representing eight strains of
Bacillus stearothermophilus
did not yield a culture that would produce amylase at both 37 and 55 C.
Photoprotection by Dipicolinate Against Inactivation of Bacterial Spores with Ultraviolet Light
Authors: Grecz Nicholas , Tang Terry , Frank Hilmer A.
Published: January 2020

The resistance of three types of
Bacillus cereus
T spores to ultraviolet radiation corresponded to their dipicolinic acid (DPA) content. Photoprotection against ultraviolet light was observed in DPA-containing spores and in DPA-less spores irradiated through calcium dipicolinate.
Absolute Configuration of a Metabolite in the
m
-Fission Pathway of Protocatechuate
Authors: Ritter Clare Schuld , Chapman Peter J. , Dagley Stanley
Published: January 2020

An aldolase, which is induced in
Pseudomonas testosteroni
during growth with
p
-hydroxybenzoate, preferentially attacks the R form of 4-hydroxy-4-methyl-2-oxoglutarate, a metabolite of protocatechuate catabolism.
Physiological Role of Pyruvate Carboxylase in a Thermophilic Bacillus
Authors: Sundaram T. K.
Published: January 2020

A prototrophic, thermophilic bacillus is in a state of biotin insufficiency when grown in medium consisting of inorganic salts and a carbon source. The effect of this biotin deficiency on the growth rate is severe only if the functioning of pyruvate carboxylase is essential for the utilization of the particular growth substrate. A mutant, PC2, of the thermophile devoid of active pyruvate carboxylase has been isolated. The properties of this mutant confirm the anaplerotic role of this enzyme in the utilization for growth of compounds like glucose and lactate which are catabolized via pyruvate. This conclusion is supported by the finding that revertants isolated from strain PC2 have regained simultaneously the ability to synthesize active pyruvate carboxylase and the ability to utilize glucose or lactate for growth. The growth of mutant PC2 on acetate, unlike that of the parent wild type, is inhibited when glucose or lactate is added to the medium. Secondary mutants obtained from PC2, which are resistant to such inhibition, still carry the original pyruvate carboxylase lesion but are derepressed for isocitrate lyase. This suggests that the inhibition of the growth of mutant PC2 is due to a block in the functioning of the glyoxylate cycle, produced by the glucose or lactate supplement.
Competence for Transfection in
Staphylococcus aureus
Authors: Sjöström Jan-Eric , Lindberg Martin , Philipson Lennart
Published: January 2020

Lysogenicity with phage P11 is a requirement for competence in the presence of calcium ions in
Staphylococcus aureus
8325N. The wild-type strain 8325N, lysogenic for the phages P11, P12, and P13, is also competent, but strain 8325-4, a nonlysogenic derivative of strain 8325N, as well as strains 8325-4 (P12) and 8325-4 (P13) could not develop competence. Preincubation of strain 8325-4 with culture filtrates from a competent strain can induce competence, but rabbit anti-P11 serum can neutralize the competence factor. Superinfection of competent strain 8325-4 (P11) with phage P11 at high multiplicities increases the transfection frequency. Uptake of deoxyribonucleic acid by competent cells is dependent on calcium ion concentration,
p
H, and temperature. Inhibition of energy metabolism or protein synthesis before and during incubation with deoxyribonucleic acid affects the binding and uptake. The ability to develop competence during bacterial growth differs between the wild-type strain (8325N) and a nuclease-deficient mutant (8325N
nuc
). The wild-type strain has a narrow competence maximum in the early exponential growth phase where no extracellular nuclease activity is produced. The
nuc
strain shows in addition competence maxima later in the exponential growth phase.
3-Ketoglucose Reductase of
Agrobacterium tumefaciens
Authors: Hayano Koichi , Tsubouchi Yukio , Fukui Sakuzo
Published: January 2020

Two kinds of 3-ketoglucose-reducing enzyme were partially purified from the sonic extract of
Agrobacterium tumefaciens
IAM 1525 grown on a sucrose-containing medium. Both enzymes have a specific requirement for reduced nicotinamide adenine dinucleotide phosphate (NADPH) as a hydrogen donor and catalyze the reduction of 3-ketoglucose to glucose but do not reduce 3-ketoglucosides such as 3-ketosucrose, 3-ketoglucose-1-phosphate, 3-ketotrehalose, and 3-ketocellobiose. From the requirement and substrate specificity of the enzymes, the name NADPH:3-ketoglucose oxidoreductase (trivial name, 3-ketoglucose reductase) was proposed. By diethylaminoethyl-cellulose column chromatography, two reductases were separated, and the early and late eluted enzymes were designated reductase I and II, respectively.
K
m
values of reductase I and II were as follows: for 3-ketoglucose both had an identical value of 2.5 × 10
−5
m
, and for NADPH the values were 1.0 × 10
−5
m
and 1.5 × 10
−5
m
, respectively. Optimal
p
H values were also identical:
p
H 4.8 to 5.0 in 10
−2
m
phosphate buffer. Intracellular localization of the enzymes is discussed.
Purification and Identification of the Fruiting-Inducing Substances inCoprinus macrorhizus
Authors: Uno Isao , Ishikawa Tatsuo
Published: January 2020

Substances which are effective in inducing fruiting bodies in monokaryotic mycelia of thefis+strain ofCoprinus macrorhizuswere purified and characterized. The active components of fruiting-inducing substances were identified as adenosine-3′-monophosphate, adenosine 3′,5′-cyclic monophosphate (cyclic AMP), and a protein which is bound with the cyclic AMP. Cyclic AMP was synthesized from adenine within mycelia of the mutant strains which form monokaryotic fruiting bodies without the addition of fruiting-inducing substances, but not in those of the strains which do not form monokaryotic fruiting bodies. The proteins which bind with cyclic AMP were detected in crude extracts of mycelia of those strains which form monokaryotic fruiting bodies and of the dikaryon, but not in those of the strains which do not form monokaryotic fruiting bodies.
Metabolism of Adenosine 3′,5′-Cyclic Monophosphate and Induction of Fruiting Bodies inCoprinus macrorhizus
Authors: Uno Isao , Ishikawa Tatsuo
Published: January 2020

The adenyl cyclase and phosphodiesterase metabolizing adenosine 3′,5′-cyclic monophosphate (cyclic AMP) were detected in mycelia of strains ofCoprinus macrorhizuswhich form fruiting bodies, but not in those of strains which do not form fruiting bodies. The adenyl cyclase synthesized cyclic AMP from adenosine triphosphate. The phosphodiesterase degrded cyclic AMP to adenosine-5′-monophosphate and was inhibited by adenosine-3′-monophosphate, theophylline, and caffeine. The strains which form fruiting bodies incorporated and metabolized cyclic AMP, but strains which do not form fruiting bodies did not. The possible participation of cyclic AMP in the induction of fruiting bodies is discussed.
Macromolecular Synthesis During the Germination of
Saccharomyces cerevisiae
Spores
Authors: Rousseau Paul , Halvorson Harlyn O.
Published: January 2020

After the dormancy of
Saccharomyces cerevisiae
ascospores had been broken, the synthesis of proteins was observed first, followed rapidly by synthesis of ribonucleic acid (RNA) and much later by deoxyribonucleic acid (DNA) synthesis. Phosphoglucomutase activity increased in a periodic (step) fashion, whereas the activity of five other enzymes increased linearly during germination and outgrowth. The rate of synthesis of these enzymes was highest at about the period of DNA replication. The amino acid pools of dormant spores contained high levels of proline, glutamic acid, and histidine. At 2 h after onset of germination, the pools of phenylalanine and methionine had disappeared and the other components had decreased significantly. By 3.5 h, with the exception of proline and cystine, most amino acid pool components had significantly increased.
Use of Fluorouracil-Uracil Combinations to Study Growth Accompanied by Insufficient Deoxyribonucleic Acid Synthesis in
Bacillus cereus
Authors: Doolittle Charles H. , Mandel H. George , Hahn Gerald A.
Published: January 2020

5-Fluorouracil (FU) at a concentration of 16 μM almost totally inhibited deoxyribonucleic acid (DNA) synthesis and cell division by
Bacillus cereus
, whereas growth continued at an exponential rate (25% of control for at least 3 h). In cultures simultaneously given 160 μM uracil (U) along with the FU, DNA synthesis still stopped, but cell division continued for one generation at the control rate and at a much slower rate beyond that; in the meantime, cell mass continued to increase at an essentially normal rate. The cells in cultures treated with FU or FU plus U were elongated and contained about half of the control content of DNA, with one nuclear area per cell instead of two. Loss of cloning ability, unlike mass increase, was always correlated with the continuing inhibition of DNA synthesis, in either FU- or U plus FU-treated cultures.
Proton Magnetic Resonance Spectroscopy of
Klebsiella
Capsular Polysaccharides
Authors: Bebault G. M. , Choy Y. M. , Dutton G. G. S. , Funnell N. , Stephen A. M. , Yang M. T.
Published: January 2020

The presence of acetate and pyruvate groups in
Klebsiella
capsular polysaccharides may be demonstrated and estimated quantitatively by running the proton magnetic resonance spectrum of the polysaccharide (as sodium salt) in deuterium oxide at 95 C. Such spectra also permit an assessment to be made of the number of α- and β-linkages in the repeat unit of the polysaccharide structure.
Immunologically Cross-Reacting Proteins in Cell Walls of Many Bacteria
Authors: Rittenhouse Harry G. , Rodda J. Barry , McFadden Bruce A.
Published: January 2020

Antibodies to a protein present in the cell envelope of
Hydrogenomonas facilis
agglutinate many gram-negative bacteria and a few gram-positive bacteria. Immunodiffusion studies of extracts from the various organisms tested indicate the presence of components sharing antigenic determinants with the cell envelope protein in all bacteria which can be agglutinated and a few that cannot. Cross-reacting components were not detected in extracts of
Mycoplasma laidlawii, Anacystis nidulans
, and several eukaryotic organisms.
Purification and Properties of a Glycoprotein Acid Phosphatase from
Candida albicans
Authors: Odds Frank C. , Hierholzer John C.
Published: January 2020

An acid phosphomonoesterase was purified 87-fold with a 4% recovery from disintegrated cells of
Candida albicans
by four stages of column chromatography. The purified enzyme was homogeneous by ultracentrifugal, electrophoretic, and immunological analyses. The fully corrected sedimentation coefficient,
s
20,w
, was calculated to be 5.51
s
. Molecular weight estimated from ultracentrifugal data was 124.3 × 10
3
, from gel chromatography was 115 × 10
3
, and from acrylamide gel electrophoretic data was 131 × 10
3
. Buoyant density in sucrose was 1.15 g/cm
3
. The enzyme was a mannoprotein with a hexose to protein ratio of 7: 1. The Michaelis constant of the enzyme was 3.3 × 10
−4
M for
p
-nitrophenyl phosphate as substrate, and the pH optimum was 4.5. The enzyme was competitively inhibited by inorganic phosphate (

K
i

= 10
−4
M) and by arsenate (

K
i

= 0.5 × 10
−4
M). A wide range of inorganic cations and anions did not affect enzyme activity, but Hg
2+
, Cd
2+
, and Cu
2+
were inhibitory. F
−
was also inhibitory at low concentrations, but the effect was reversed at higher concentrations. Phosphatase activity was completely destroyed by exposure of the enzyme to 70 C for 12 min, but was destroyed only slowly by proteolytic hydrolysis. The purified glycoprotein enzyme gave a line of identity with the “b” antigen of crude
C. albicans
homogenates in immunodiffusion and immunoelectrophoresis tests with sera from rabbits inoculated with intact
C. albicans
cells and from humans with proven candidiasis. Preliminary evidence suggests that the mannan and not the protein portion of the enzyme molecule is responsible for this antigenicity.
Electron Micrography of Bud Formation in
Metschnikowia krissii
Authors: Talens L. T. , Miranda Mary , Miller M. W.
Published: January 2020

The fine structure of bud formation of
Metschnikowia krissii
was studied by means of ultramicrotomy and transmission electron microscopy. Bud protrusion and development were observed by scanning electron microscopy. Bud formation in this yeast takes place by an extension of a small localized area of the existing parent wall. The parent cell and its bud are initially separated by the plasmalemma, creating an intercellular site within which the generation of new cell wall (bud and birth scar areas) occurs centripetally. When the dividing wall is complete and new cell wall material is formed, a narrow cleavage plane becomes increasingly defined. This cleavage plane apparently proceeds laterally toward the direction of the existing outer walls which rupture, resulting in the separation of the bud from the parent cell. The bud scar is prominently convex in shape; the birth scar is less conspicuous and initially concave in shape. Comparison of bud formation in
M. krissii
is made with that observed in
Saccharomyces cerevisiae
and
Rhodotorula glutinis
.
Increase in Sensitivity to Antibiotics and Lysozyme on Deletion of Lipopolysaccharides in
Escherichia coli
Strains
Authors: Tamaki Shigeo , Matsuhashi Michio
Published: January 2020

Lipopolysaccharides on the cell surface of
Escherichia coli
prevent penetration of lysozyme or certain low-molecular-weight drugs.
Sodium and Potassium Requirements for Active Transport of Glutamate by
Escherichia coli
K-12
Authors: Halpern Y. S. , Barash H. , Dover S. , Druck Karnina
Published: January 2020

Active transport of glutamate by
Escherichia coli
K-12 requires both Na
+
and K
+
ions. Increasing the concentration of Na
+
in the medium results in a decrease in the

K
m

of the uptake system for glutamate; the capacity is not affected. Glutamate uptake by untreated cells is not stimulated by K
+
. K
+
-depleted cells show a greatly reduced capacity for glutamate uptake. Preincubation of such cells in the presence of K
+
fully restores their capacity for glutamate uptake when Na
+
ions are also present in the uptake medium. Addition of either K
+
or Na
+
alone restores glutamate uptake to only about 20% of its maximum capacity in the presence of both cations. Changes in K
+
concentration affect the capacity for glutamate uptake but have no effect on the

K
m

of the glutamate transport system. Ouabain does not inhibit the (Na
+
-K
+
)-stimulated glutamate uptake by intact cells or spheroplasts of
E. coli
K-12.
Inactivation of Aspartic Transcarbamylase in Sporulating
Bacillus subtilis
: Demonstration of a Requirement for Metabolic Energy
Authors: Waindle Louise M. , Switzer R. L.
Published: January 2020

The aspartic transcarbamylase (ATCase) activity of
Bacillus subtilis
cells disappears rapidly from stationary-phase cells prior to sporulation. ATCase activity does not appear in the culture fluid during the stationary phase; hence the enzyme appears to be inactivated in the cells. The enzyme is inactivated normally in two different mutants lacking proteases; the activity is very stable in crude extracts of cells or in the culture fluid. These results suggest that ATCase is not inactivated by the general proteolysis that occurs in sporulating bacteria. The inactivation of ATCase can be completely inhibited after it has begun by oxygen starvation or addition of fluoroacetate. Inhibitors of oxidative phosphorylation and electron transport also interrupt the inactivation of ATCase. The inactivation of ATCase is very slow in two mutant strains that are deficient in enzymes of tricarboxylic acid cycle. Addition of gluconate to stationary cultures of the mutant strains, which is known to restore depleted adenosine 5′-triphosphate pools in these bacteria, also restores inactivation of ATCase. These experiments support the conclusion that the generation of metabolic energy is necessary for the inactivation of ATCase in stationary cells. ATCase activity is stable in growing cells in which ATCase synthesis is repressed by addition of uracil; the enzyme is inactivated normally, however, when such cells cease growing.
Effects of Toluene and Phenethyl Alcohol on the Ultrastructure of
Escherichia coli
Authors: Woldringh C. L.
Published: January 2020

Treatment of
Escherichia coli
cells with 0.25% toluene caused partial dissolution of the plasma membrane concomitant with displacement of nuclear material towards the cell periphery. By contrast, treatment with 0.25% phenethyl alcohol generated intracellular membranes.
Chemical Analysis of Cell Walls and Autolytic Digests of
Bacillus psychrophilus
Authors: Best Gary K. , Mattingly Stephen J.
Published: January 2020

The amino acid composition of isolated cell walls of
Bacillus psychrophilus
has been determined before and after extraction of protein with ethylenediamine-tetraacetic acid at 45 C. This revealed that the peptidoglycan consists of Ala, Lys, and Glu in a molar ratio of 3:1:2. By using autolytic digests of log-phase cell walls, it was possible to detect 14 ninhydrin-positive degradation products. Chemical analyses of the seven major bands from these digests indicated that the amino acid sequence of the peptide subunit in the murein of this organism consists of muramyl-
l
-alanyl-γ-
d
-glutamyl-
l
-lysyl-
d
-alanine, and the linkage between adjacent peptides is supplied by a second
d
-glutamic acid which is bound to the σ-amino group of lysine and the carboxyl group of the
d
-alanine through its amino group. The nature of the solubilized wall fragments indicates that each of the peptide bonds in the murein is hydrolyzed by autolysins except the
l
-alanyl-γ-
d
-glutamyl linkage.
Fatty Acid Composition of L-Forms of
Streptococcus faecalis
Cultured at Different Osmolalities
Authors: Montgomerie J. Z. , Kalmanson G. M. , Guze L. B.
Published: January 2020

The fatty acid composition of the membranes of three different penicillin-produced L-forms of
Streptococcus faecalis
was determined: (i) a stable (nonreverting) L-form (T
53
) cultured in brain heart infusion (BHI) with 0.5 M sucrose; (ii) a stable L-form (T
531
) cultured in BHI without sucrose; and (iii) an unstable L-form (T
9
) cultured in BHI with 0.5 M sucrose and 1,000 U of penicillin per ml. L-forms were obtained by centrifugation and lysed by washing in 1 mM tris(hydroxymethyl)aminomethane-hydrochloride buffer. The parent
S. faecalis
was also cultured in BHI and BHI containing 0.5 M sucrose, and washed with buffer. The fatty acid composition of L-forms of
S. faecalis
cultured in BHI without sucrose (370 mosmol) had higher C
18:1
and lower C
18
than L-forms cultured in the same media with added 0.5 M sucrose (950 mosmol) in both exponential and stationary cultures. In the stationary phase of growth, C
19
was reduced in the L-forms cultured without sucrose. Similar changes were seen in the parent
S. faecalis
cultured in the two types of media. These changes in membrane fatty acids may relate to osmo-regulation of the L-forms.
Transport of Vitamin B
12
in
Escherichia coli
: Common Receptor Sites for Vitamin B
12
and the E Colicins on the Outer Membrane of the Cell Envelope
Authors: Di Masi Donna R. , White John C. , Schnaitman Carl A. , Bradbeer Clive
Published: January 2020

The first step in the transport of cyanocobalamin (CN-B
12
) by cells of
Escherichia coli
was shown previously to consist of binding of the B
12
to specific receptor sites located on the outer membrane of the cell envelope. In this paper, evidence is presented that these B
12
receptor sites also function as the receptors for the E colicins, and that there is competition between B
12
and the E colicins for occupancy of these sites. The cell strains used were
E. coli
KBT001, a methionine/B
12
auxotroph, and B
12
transport mutants derived from strain KBT001. Colicins E1 and E3 inhibited binding of B
12
to the outer membrane B
12
receptor sites, and CN-B
12
protected cells against these colicins. Half-maximal protection was given by CN-B
12
concentrations in the range of 1 to 6 nM, depending upon the colicin concentration used. Colicin E1 competitively inhibited the binding of
57
Co-labeled CN-B
12
to isolated outer membrane particles. Functional colicin E receptor sites were found in cell envelopes from cells of only those strains that possessed intact B
12
receptors. Colicin K did not inhibit the binding of B
12
to the outer membrane receptor sites, and no evidence was found for any identity between the B
12
and colicin K receptors. However, both colicin K and colicin E1 inhibited the secondary phase of B
12
transport, which is believed to consist of the energy-coupled movement of B
12
across the inner membrane.
Quantitative Measurement of the Effectiveness of Unsaturated Fatty Acids Required for the Growth of
Saccharomyces cerevisiae
Authors: Barber Eugene D. , Lands William E. M.
Published: January 2020

The growth response of a mutant of
Saccharomyces cerevisiae
which is unable to synthesize unsaturated fatty acids has been measured in the presence of variable concentrations of exogenous unsaturated fatty acids. Final cell yields, doubling times, and lag times were all found to vary as a function of the initial concentration of the added unsaturated acid. The cell yield was found to be a convenient quantitative measurement to use in comparing the effectiveness of various unsaturated acids. Values for the acids ranged from 1.7 to 11 cells per femtomole with values for oleate and palmitoleate at 2.7 and 4.3 cells per femtomole, respectively. In general, the effectiveness of unsaturated acids was found to increase with an increasing number of double bonds. Saturated fatty acids of a chain length of 5 to 18 carbon atoms were completely ineffective. The varied efficiencies of different unsaturated fatty acids indicate that unsaturation per se was not the basis of the nutritional requirement and indicate certain acids that would be useful in further studies of the role of unsaturated acids in cell function.
Electron Transport System Associated with Membranes of
Bacillus cereus
During Vegetative Growth and Sporulation
Authors: Felix J. A. , Lundgren D. G.
Published: January 2020

Membranes isolated from
Bacillus cereus
ATCC 4342 during vegetative growth and during sporulation contained cytochromes
b, c
and
a
+
a
3
as well as flavoprotein as determined from reduced-minus-oxidized difference spectra. Although there appeared to be no qualitative change in the cytochromes, there was a significant increase in the amount of cytochromes associated with membranes isolated from sporulating cells. Succinate and nicotinamide adenine dinucleotide (reduced form) (NADH) reduced the same cytochromes indicating similar pathways of electron transport. The electron transport inhibitors—cyanide, azide, 2-heptyl-4-hydroxyquinoline-
N
-oxide, dicumarol and atebrine—were examined for their effect on succinate oxidase (succinate: [O
2
] oxidoreductase) and NADH oxidase (NADH: [O
2
] oxidoreductase). NADH oxidase associated with vegetative cell membranes was less sensitive to certain inhibitors than was succinate oxidase, suggesting a branched electron transport pathway for NADH oxidation. In addition to electrons being passed to O
2
through a quinone-cytochrome chain, it appears that these intermediate carriers can be bypassed such that O
2
is reduced by electrons mediated by NADH dehydrogenase. Both oxidases associated with sporulating cell membranes were inhibited to a lesser degree than were the oxidases associated with vegetative cell membranes.
Pathway of
n
-Alkane Oxidation in
Cladosporium resinae
Authors: Walker J. D. , Cooney J. J.
Published: January 2020

Pathways of initial oxidation of
n
-alkanes were examined in two strains of
Cladosporium resinae
. Cells grow on dodecane and hexadecane and their primary alcohol and monoic acid derivatives. The homologous aldehydes do not support growth but are oxidized by intact cells and by cell-free preparations. Hexane and its derivatives support little or no growth, but cell extracts oxidize hexane, hexanol, and hexanal. Alkane oxidation by extracts is stimulated by reduced nicotinamide adenine dinucleotide (phosphate). Alcohol and aldehyde oxidation are stimulated by nicotinamide adenine dinucleotide (phosphate), and reduced coenzymes accumulate in the presence of cyanide or azide. Extracts supplied with
14
C-hexadecane convert it to the alcohol, aldehyde, and acid. Therefore, the major pathway for initial oxidation of
n
-alkanes is via the primary alcohol, aldehyde, and monoic acid, and the system can act on short-, intermediate-, and long-chain substrates. Thus, filamentous fungi appear to oxidize
n
-alkanes by pathways similar to those used by bacteria and yeasts.
Regulation by Membrane Fluidity of the Allosteric Behavior of the (Ca
2+
)-Adenosine Triphosphatase from
Escherichia coli
Authors: Siñeriz Faustino , Bloj Bernabé , Farías Ricardo N. , Trucco Raúl E.
Published: January 2020

The allosteric properties of the membrane-bound (Ca
2+
)-adenosine triphosphatase of an unsaturated fatty acid auxotroph of
Escherichia coli
were studied in membranes with different fatty acid compositions. The Hill coefficient of the inhibition by Na
+
ranged from 1.4, in the case where the auxotroph was grown with
cis
-vaccenic acid as supplement, to 2.8 when grown on linolenic acid. The results indicate that no fatty acid is particularly involved in the allosteric phenomena. A correlation between the values of the Hill coefficient and the double bond index or the ratio of the double bond index saturated to the fatty acids of the membrane was found. These facts are interpreted as a modulation by the membrane fluidity of the allosteric behavior of the membrane-bound enzyme. The general biological character of this phenomenon is discussed in this paper.
Fate of Labeled Hydroxamates During Iron Transport from Hydroxamate-Iron Chelates
Authors: Arceneaux Jean E. L. , Davis W. B. , Downer D. N. , Haydon A. H. , Byers B. R.
Published: January 2020

The fate of the hydroxamic acid-iron transport cofactors during iron uptake from the
59
Fe
3+
chelates of the
3
H-labeled hydroxamates schizokinen and aerobactin was studied by assay of simultaneous incorporation of both
59
Fe
3+
and
3
H. In the schizokinen-producing organism
Bacillus megaterium
ATCC 19213 transport of
59
Fe
3+
from the
3
H-schizokinen-
59
Fe
3+
chelate at 37 C was accompanied by rapid uptake and release (within 2 min) of
3
H-schizokinen, although
3
H-schizokinen discharge was temperature-dependent and did not occur at 0 C. In the schizokinen-requiring strain
B. megaterium
SK11 similar release of
3
H-schizokinen occurred only at elevated concentrations of the double-labeled chelate; at lower chelate concentrations,
3
H-schizokinen remained cell-associated. Temperature-dependent uptake of deferri (iron-free)
3
H-schizokinen to levels equivalent to those incorporated from the chelate form was noted in strain SK11, but strain ATCC 19213 showed only temperature-independent binding of low concentrations of deferri
3
H-schizokinen. These results indicate an initial temperature-independent binding of the ferric hydroxamate which is followed rapidly by temperature-dependent transport of the chelate into the cell and an enzyme catalyzed separation of iron from the chelate. The resulting deferri hydroxamate is discharged from the cell only when a characteristic intracellular concentration of the hydroxamate is exceeded, which happens in the schizokinen-requiring strain only at elevated concentrations of the chelate. This strain also appears to draw the deferri hydroxamate into the cell by a temperature-dependent mechanism. The aerobactin-producing organism
Aerobacter aerogenes
62-1 also demonstrated rapid initial uptake and temperature-dependent discharge of
3
H-aerobactin during iron transport from
3
H-aerobactin-
59
Fe
3+
, suggesting a similar ferric hydroxamate transport system in this organism.
Efficiency of Energy Conversion by Aerobic Glucose Metabolism in
Aphanocapsa
6714
Authors: Pelroy Richard A. , Bassham James A.
Published: January 2020

Efficiency of adenosine triphosphate (ATP) formation from glucose oxidation in
Aphanocapsa
6714 was estimated by quantitative measurement of phosphorylated intermediary metabolites and glycogen (polyglucose) formed from
14
C-glucose. P/2e ratios based on oxygen uptake ranged from 2.62 to 3.08, whereas those based on
14
CO
2
evolution ranged from 1.66 to 1.72. The synthesis of glycogen, which is the dominant energy-consuming process in resting cells exposed to exogenous glucose, was almost totally inhibited under anaerobic conditions, and the cellular concentration of ATP decreased steadily. Thus, both net synthesis of ATP and the steady-state concentration of ATP are obligatorily linked to respiration in this heterotrophic unicellular blue-green alga.
Induction of Unbalanced Growth and Death of
Streptococcus sanguis
by Oxygen
Authors: Eisenberg Roselyn J.
Published: January 2020

Streptococcus sanguis
has normal streptococcal morphology when grown in a nitrogen atmosphere but undergoes gross morphological alterations when grown in the presence of oxygen (O cells). Studies were made of the relationship between the development of pleomorphism and the loss of viability which accompanied it in O cultures of
S. sanguis
. The development of pleomorphism appears to involve two events. The first step, or triggering event, occurs in log-phase cultures in the presence of oxygen. The second step, or manifestation of pleomorphism, occurs at stationary phase in the presence or absence of oxygen. The loss of viability appears to be related both to the length of time the culture is exposed to oxygen as well as to a specific event which occurs at the transition from log to stationary phase. Oxygen also induced a state of unbalanced growth in
S. sanguis
in which the proportions of deoxyribonucleic acid, ribonucleic acid, and protein synthesized were altered. The relationship of these alterations to the development of pleomorphism is discussed.
Isolation and Characterization of Two Protease-Producing Mutants from
Staphylococcus aureus
Authors: Rydén Ann-Christine , Lindberg Martin , Philipson Lennart
Published: January 2020

Two mutants with increased protease production were isolated after nitrosoguanidine treatment of
Staphylococcus aureus
8325N. The wild type produces low amounts of extracellular proteolytic activity. The enzyme was inducible and could only be detected if casein or preferably skim milk powder was used as inducer. The optimal pH, salt concentration, and media for enzyme production were determined. The mutants differed from the wild type in several phenotypic characters. The pattern of extracellular deoxyribonuclease and alkaline phosphatase differed between the mutants and the wild type. Several carbohydrates such as lactose, galactose, and mannitol were not utilized by the mutants, probably owing to a block in the uptake. Glucose could, however, be utilized by the mutants. Reversion frequency to wild type with regard to carbohydrate utilization was spontaneously high, and all revertants regained the parental pattern irrespective of the carbohydrate used for selection. The results suggest that a single locus may control the excretion of extracellular enzymes and carbohydrate uptake in
S. aureus
.
Growth in High Osmotic Medium of an Unsaturated Fatty Acid Auxotroph of
Escherichia coli
K-12
Authors: Broekman J. H. F. F. , Steenbakkers Johan F.
Published: January 2020

A temperature-sensitive mutant of
Escherichia coli
K-12, which is impaired in the biosynthesis of the unsaturated fatty acids at 42 C, continues to grow and remains viable in a medium with a high osmotic pressure. Under these growth conditions, 50% of the fatty acids of the parental strain and 80% of the fatty acids of the mutant strain are saturated.
Carbohydrate Metabolism in
Agrobacterium tumefaciens
Authors: Arthur Larry O. , Bulla Lee A. , Julian Grant St. , Nakamura Lawrence K.
Published: January 2020

The activity of pentose cycling (PC) reactions in
Agrobacterium tumefaciens
is much greater than that normally found in bacteria, and in this regard the organism represents a unique category. Equations specifically derived from radiorespirometric data for bacteria with high PC activity in the presence of an alternate pathway are presented.
A. tumefaciens
utilizes
d
-glucose by strictly aerobic mechanisms involving the Entner-Doudoroff (ED) and PC pathways; relative participation by the ED pathway is 55% and by the PC cycle, 44%. The 3-ketoglycose-synthesizing system in the bacterium does not affect the relative participation of these two pathways. Radiorespirometric and enzymatic analyses clearly demonstrate that the Embden-Meyerhof-Parnas pathway does not function. Studies on the oxidation of pyruvic, acetic, succinic, and glutamic acids show that terminal respiration includes both the tricarboxylic acid and glyoxylic acid cycles.
Regulation of the Nicotinamide Adenine Dinucleotide- and Nicotinamide Adenine Dinucleotide Phosphate-Dependent Glutamate Dehydrogenases of
Saccharomyces cerevisiae
Authors: Roon Robert J. , Even Harvey L.
Published: January 2020

Saccharomyces cerevisiae
contains two distinct
l
-glutamate dehydrogenases. These enzymes are affected in a reciprocal fashion by growth on ammonia or dicarboxylic amino acids as the nitrogen source. The specific activity of the nicotinamide adenine dinucleotide phosphate (NADP) (anabolic) enzyme is highest in ammonia-grown cells and is reduced in cells grown on glutamate or aspartate. Conversely, the specific activity of the nicotinamide adenine dinucleotide (NAD) (catabolic) glutamate dehydrogenase is highest in cells grown on glutamate or aspartate and is much lower in cells grown on ammonia. The specific activity of both enzymes is very low in nitrogen-starved yeast. Addition of the ammonia analogue methylamine to the growth medium reduces the specific activity of the NAD-dependent enzyme and increases the specific activity of the NADP-dependent enzyme.
Ribosomes and Ribonucleic Acids of
Coxiella burneti
Authors: Baca O. G. , Hersh R. T. , Paretsky D.
Published: January 2020

This report describes the direct isolation and characterization of rickettsial ribosomes. Ribosomes from the rickettsia
Coxiella burneti
were isolated and partially characterized. The ribosomes had a sedimentation constant of about 70
S
and could be dissociated into 50 and 30
S
subunits. Electron microscopy revealed ribosomal particles with dimensions similar to those reported for other procaryotic organisms. Ribonucleic acid (RNA) species (23 and 16
S
) were isolated from the ribosomal particles. The nucleotide compositions of the ribosomal RNAs were found to be similar to those reported for bacterial ribosomal RNA. In addition to the high-molecular-weight ribosomal RNA, 5
S
RNA was also extracted from the organism.
Degradation of Cellular Deoxyribonucleic Acid After Gamma Irradiation of Spheroplasted
Escherichia coli
CR
thy
−
Cells
Authors: Christensen R. C. , Keller K. , Pollard E. C.
Published: January 2020

Gamma-ray-irradiated
Escherichia coli
CR
thy
−
cells and spheroplasts, prelabeled with
14
C-thymine, were assayed for acid-insoluble activity as a function of incubation time after irradiation. Under similar irradiation and incubation conditions, degradation profiles of cells and spheroplasts were virtually identical. Similar results were found for cells and protoplasts irradiated in the presence of rifampin (20 μg/ml). These results suggest that postirradiation deoxyribonucleic acid degradation enzymes are probably not loosely localized in the periplasm, unlike endonuclease I.
Temperature-Sensitive Growth Inhibition by Valine in
Salmonella typhimurium
: Alteration of One Form of Acetohydroxy Acid Synthetase
Authors: O'Neill J. Patrick , Freundlich Martin
Published: January 2020

A strain of
Salmonella typhimurium
, MF1680, was isolated that required isoleucine for normal growth at 37 C but not at 27 C. In minimal medium the growth of MF1680 was strongly blocked by valine. Growth inhibition was reversed by isoleucine. When this mutant was grown at 37 C, the form of acetohydroxy acid synthetase not inhibited by valine, (AHAS
R
), could not be detected. The site of this mutation in AHAS
R
, termed
ilvG
, was found to map in the
ilv
gene cluster between
ilvD
and
ilvE
.
Transport of Octanoate by
Pseudomonas oleovorans
Authors: Toscano William A. , Hartline Richard A.
Published: January 2020

The properties of a system for octanoate transport in
Pseudomonas oleovarans
are described. Transport is inducible and energy dependent, shows saturation kinetics, and concentrates against a gradient. Optimal transport is at pH 6.0 and 28 C. Apparent

K
m

and

V
max

values are, respectively, 7.0 μM octanoate and 0.68 nmol of octanoate transported per min per mg (dry mass) of cells. Fatty acids from C
7
to C
12
are competitive inhibitors, whereas alkanes, alkenes, and esters of the same carbon chain lengths show no inhibition. The

K
i

values for heptanoate, nonanoate, decanoate, undecanoate, and dodecanoate are 17, 3.4, 3.2, 1.2, and 2.4 μM, respectively. The molecular specificity of this transport system is a linear hydrocarbon chain of no less than 6 to at least 11 carbon atoms and a carboxyl group.
Altered Mitochondrial Respiration in a Chromosomal Mutant of
Neurospora crassa
Authors: Edwards David L. , Kwiecinski Fabia
Published: January 2020

A mutant of
Neurospora crassa
(
cni
-1) has been isolated that has two pathways of mitochondrial respiration. One pathway is sensitive to cyanide and antimycin A, the other is sensitive only to salicyl hydroxamic acid. Respiration can proceed through either pathway and both pathways together in this mutant account for greater than 90% of all mitochondrial respiration. The
cni
-1 mutation segregates as a nuclear gene in crosses to other strains of
Neurospora
. Absorption spectra of isolated mitochondria from
cni
-1 show typical
b
- and
c
-type cytochromes but the absorption peaks corresponding to cytochrome
aa
3
are not detectable. Extraction of soluble cytochrome
c
-546 from these mitochondria followed by reduction with ascorbate reveals a new absorption peak at 426 nm that is not present in wild-type mitochondria. This peak may be due to an altered cytochrome oxidase with abnormal spectral properties. Mitochondria from
cni
-1 have elevated levels of succinate-cytochrome
c
reductase but reduced levels of nicotinamide adenine dinucleotide reduced form cytochrome
c
reductase and of cyanide- and azide-sensitive cytochrome
c
oxidase. These studies suggest that the
cni
-1 mutation results in the abnormal assembly of cytochrome
c
oxidase so that the typical cytochrome
aa
3
spectrum is lost and the enzyme activity is reduced. As a consequence of this alteration, a cyanide-insensitive respiratory pathway is elaborated by these mitochondria which may serve to stimulate adenosine 5′-triphosphate production via substrate level phosphorylation by glycolysis and the Krebs cycle.
Cyclic 3′,5′-Adenosine Monophosphate Phosphodiesterase of
Escherichia coli
Authors: Nielsen L. D. , Monard D. , Rickenberg H. V.
Published: January 2020

The cyclic 3′,5′-adenosine monophosphate (c-AMP) phosphodiesterase from
Escherichia coli
has been partially purified. The enzyme has an apparent molecular weight of 30,000, a Michaelis constant of 0.5 mM c-AMP, and a pH optimum of 7. The partially purified enzyme requires for activity the presence of a reducing compound and of either iron or a protein which seemingly acts as iron carrier.
Freeze-Etching of the Cell Envelope of an
Acinetobacter
Species Which Carries a Regular Array of Surface Subunits
Authors: Sleytr U. B. , Thornley Margaret J.
Published: January 2020

Freeze-etching was applied to preparations, with and without glycerol, of
Acinetobacter
sp. strain MJT/F5/199A, consisting of intact cells after normal growth or after incubation with chloramphenicol, spheroplasts, and isolated cell walls and outer membranes. Etched preparations show that a regular array of subunits forms the surface of normal cells. Near the zones of constriction in dividing cells, blebs and irregularities are seen, and some blebs, consisting of both surface subunits and outer membrane, are released from the cells. The cross-fractured cell envelope shows four layers which are related to the structures seen in section as follows: cw1, which is not visible in section, contains the surface subunits; cw2 consists of all or part of the outer membrane; cw3 includes the intermediate and dense, peptidoglycan-containing layers; within these cell wall layers is the plasma membrane. Internal fracture of the plasma membrane occurs under all conditions tested, but the fracture plane in the cell wall is only revealed in chloramphenicol-treated cells or normal cells freeze-fractured with glycerol present; the characteristic fracture faces are not seen in spheroplasts or isolated outer membranes. The concave fracture face w2 consists of densely packed granules, while the convex face w3 is fibrillar. The probable location of this fracture plane is discussed. After incubation with chloramphenicol, the outer surface of the cells is obscured by extracellular material, the dense peptidoglycan-containing layer is increased in thickness, and the cytoplasm contains rounded bodies bounded by one or more unit membranes.
Mercury and Cadmium Resistances Mediated by the Penicillinase Plasmid in
Staphylococcus aureus
Authors: Kondo Isamu , Ishikawa Tomoaki , Nakahara Hideomi
Published: January 2020

Resistance of
Staphylococcus aureus
mediated by the penicillinase (Pc-ase) plasmid to divalent metal ions of Hg and Cd was found to be controlled by different mechanisms. The Hg resistance of the Pc-ase plasmid-carrying organisms is based upon a process of changing the ion incorporated in the cell into a somewhat innocuous form. This process is independent of temperature and seems to be controlled by an inducible enzyme. The killing effect of Hg salts was not influenced by the coexistence of other di- or monovalent ions such as MgCl
2
, CaCl
2
, MnCl
2
, and NaCl. No vaporization of Hg, which explains the resistance mechanism such as that proposed by Komura et al. for R factor-mediated Hg resistance in enterobacilli, was found in the case of Hg resistance in staphylococci. On the other hand, the resistance to Cd ion is mediated by some protective mechanism to retain the ion outside the cell. Pc-sensitive organisms not carrying the Pc-ase plasmid incorporate Cd ions into the cells, whereas the Pc-ase plasmid-carrying organisms do not. The incorporation of this ion is temperature dependent and does not take place at 4 C. When incubated with this ion at 4 C, Pc-sensitive organisms as well as Pc-resistant organisms are also able to show a resistance. The addition of CaCl
2
could eliminate the killing effect of CdCl
2
with a dose-effective response.
Histidine Regulation in
Salmonella typhimurium
XV. Procedure for the Selection of Mutants Unable to Derepress the Histidine Operon
Authors: Straus Daniel S. , Wyche James H.
Published: January 2020

A general search has been made for mutants defective in their ability to derepress the histidine operon. The procedure was to select for mutants with an increased sensitivity to the false feedback inhibitor, 2-thiazolealanine. Five mutant strains defective in derepression have been isolated. All five strains are unable to derepress normally because of mutations located in the operator-promoter region of the histidine operon.
Surface-Bound Nuclease of
Staphylococcus aureus
: Localization of the Enzyme
Authors: Okabayashi Kinji , Mizuno Den'ichi
Published: January 2020

The cellular localization of staphylococcus nuclease, previously known as an exoenzyme, was investigated, and the following results were obtained. (i) When
Staphylococcus aureus
cells were converted to protoplasts by cell wall lytic enzyme L-11 (a bacteriolytic enzyme purified from
Flavobacterium
sp. which specifically hydrolyzes amide and peptide linkages of murein layers), over 80% of the cell-bound nuclease was released into the surrounding sucrose medium. (ii) The cell-bound nuclease was associated with the cell-wall membrane fraction of mechanically disrupted cells. (iii) The nuclease activity of cell-wall membrane fractions from cells during early and late stages of protoplast formation were compared. Less activity was found in the late stage. These results suggest that nuclease may be located at or near the surface of the cells. The distribution of cell-bound nuclease in the cell-wall membrane fraction varied with the growth conditions of
S. aureus
. The activity of alkaline phosphatase, another surface enzyme, was also investigated. Less of this enzyme than nuclease was released when the cells were converted to protoplasts.
Autoradiographic Study of Mannan Incorporation into the Growing Cell Walls of
Saccharomyces cerevisiae
Authors: Farkaš V. , Kovařík J. , Košinová A. , Bauer Š.
Published: January 2020

The incorporation of mannan labeled by
d
-[1-
3
H]mannose into the growing cell walls of
Saccharomyces cerevisiae
has been followed by means of high-resolution autoradiography. The results show that, in the very first stage of budding, when the shape of the bud is nearly spherical, the new mannan is incorporated uniformly over the whole surface of the emerging bud. Later on, as the bud growth proceeds, the polarized tip growth predominates. In the maturation phase of bud growth, when the size of the bud is about two-thirds that of the mother cell, again a considerable incorporation of the labeled substrate over the whole bud surface was observed. The cell wall of the mother cell remained largely unlabeled. These facts indicate that the ellipsoidal shape of the cell walls in
S. cerevisiae
is the result of the combination of polarized tip growth and nonpolarized spherical extension.