bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Ribonucleic Acid and Protein in Plasmid-Containing Minicells of
Escherichia coli
K-12
Authors: Roozen Kenneth J. , Fenwick Raymond G. , Curtiss Roy
Published: January 2020

Unlike the deoxyribonucleic acid (DNA)-deficient minicells produced by F
−
parents, minicells produced by plasmid-containing strains contain significant amounts of plasmid DNA. We examined the ability of plasmid-containing minicells to synthesize ribonucleic acid (RNA) and protein. In vivo, minicells produced by F
−
parents are unable to incorporate radioactive precursors into acid-insoluble RNA or protein, whereas minicells produced by F′, R
+
, or Col
+
parents are capable of such synthesis. Using a variety of approaches, including polyacrylamide gel analysis of the RNA species produced and electron microscope autoradiography, we demonstrated that the synthesis observed in minicell preparations is a property of the plasmid-containing minicells and not a result of the few cells (approximately 1 per 10
6
minicells) contaminating the preparations. That the observed synthesis is of biological importance is suggested by the ability of plasmid-containing minicells to yield viable phage upon infection with T4.
Effect of Nutrient Concentration on the Growth of
Escherichia coli
Authors: Shehata Talaat E. , Marr Allen G.
Published: January 2020

The relationship between specific growth rate of
Escherichia coli
and the concentration of limiting nutrient (glucose or phosphate or tryptophan) has been determined for populations in a steady state. At high concentrations the specific growth rate is independent of the concentration of nutrient, but at low concentrations the specific growth rate is a strong function of the nutrient concentration. Such a relationship was predicted by Monod; however, Monod's equation does not predict the relationship over the entire range of nutrient concentration. If parameters of the equation are estimated from the results obtained at low concentrations, then at high concentrations of nutrient, the specific growth rate is significantly higher than that predicted by Monod's equation. These results were interpreted on the basis that the rate of growth is controlled by at least two parallel reactions and that the affinities of the enzymes catalyzing these reactions are different. The relationship between specific growth rate and mean cell volume was also measured, and the results indicate that mean cell volume depends not only on the specific growth rate but also on the nature of the limiting nutrient. There are different mean cell volumes at the same specific growth rate established by different limiting nutrients. Therefore, the mean cell volume is not uniquely determined by the specific growth rate.
Paracrystalline Sheets Reaggregated from Solubilized Exosporium of
Bacillus cereus
Authors: Beaman T. Cabrera , Pankratz H. Stuart , Gerhardt Philipp
Published: January 2020

Fragments of exosporium, isolated from dormant spores of
Bacillus cereus
, were disintegrated by treatment with sodium dodecyl sulfate (SDS) or with phenol and acetic acid. After centrifugation of each preparation, proteins in the supernatant fractions were resolved by disc gel electrophoresis into either two or eight bands, respectively. The SDS-solubilized fraction contained spheroidal particles 11 to 44 nm in diameter. When centrifuged until clear, this fraction after dialysis still gave rise to crystal-like sheets which had the same lattice symmetry and major chemical components (protein, lipid, and carbohydrate) as fragments of the native exosporium.
d
-Fucose as a Gratuitous Inducer of the
l
-Arabinose Operon in Strains of
Escherichia coli
B/r Mutant in Gene
araC
Authors: Beverin Susan , Sheppard David E. , Park Sang Shin
Published: January 2020

d
-Fucose, a nonmetabolizable analogue of
l
-arabinose, prevents growth of
Escherichia coli
B/r on a mineral salts medium plus
l
-arabinose by inhibiting induction of the
l
-arabinose operon. Mutations giving rise to
d
-fucose resistance map in gene
araC
and result in constitutive expression of the
l
-arabinose operon. Most of these mutations also permit
d
-fucose to serve as a gratuitous inducer. It is concluded that
d
-fucose-resistant mutants produce an
araC
gene product with an altered inducer specificity. Addition of
l
-arabinose to cells induced with the gratuitous inducer,
d
-fucose, resulted in severe transient repression of operon expression followed by permanent catabolite repression. Transient repression but no permanent catabolite repression was obtained when cells unable to metabolize
l
-arabinose were employed. It is concluded that transport of
l
-arabinose alone is sufficient to achieve transient repression of its own operon, but that metabolism of
l
-arabinose must occur to achieve permanent catabolite repression of the
l
-arabinose operon. This general effect has been termed “self-catabolite repression.”
Active Transport of Iron in
Bacillus megaterium:
Role of Secondary Hydroxamic Acids
Authors: Davis W. B. , Byers B. R.
Published: January 2020

Kinetics of radioactive iron transport were examined in three strains of
Bacillus megaterium
. In strain ATCC 19213, which secretes the ferric-chelating secondary hydroxamic acid schizokinen,
59
Fe
3+
uptake from
59
FeCl
3
or the ferric hydroxamate Desferal-
59
Fe
3+
was rapid and reached saturation within 3 min. In strain SK11, which does not secrete schizokinen, transport from
59
FeCl
3
was markedly reduced; the two ferric hydroxamates Desferal-
59
Fe
3+
or schizokinen-
59
Fe
3+
increased both total
59
Fe
3+
uptake and the
59
Fe
3+
appearing in a cellular trichloroacetic acid-insoluble fraction, although 10 min was required to reach saturation. Certain characteristics of transport from both ferric hydroxamates and FeCl
3
suggest that iron uptake was an active process. The growth-inhibitory effect of aluminum on strain SK11 was probably due to the formation of nonutilizable iron-aluminum complexes which blocked uptake from
59
FeCl
3
. Desferal or schizokinen prevented this blockage. A strain (ARD-1) resistant to the ferric hydroxamate antibiotic A22765 was isolated from strain SK11. Strain ARD-1 failed to grow with Desferal-Fe
3+
as an iron source, and it was unable to incorporate
59
Fe
3+
from this source. Growth and iron uptake in strain ARD-1 were similar to strain SK11 with schizokinen-Fe
3+
or the iron salt as sources. It is suggested that the ferric hydroxamates, or the iron they chelate, may be transported by a special system which might be selective for certain ferric hydroxamates. Strain ARD-1 may be unable to recognize both the antibiotic A22765 and the structurally similar chelate Desferal-Fe
3+
, while retaining its capacity to utilize schizokinen-Fe
3+
.
Comparison of the Morphology and Deoxyribonucleic Acid Composition of 27 Strains of Nitrifying Bacteria
Authors: Watson Stanley W. , Mandel Manley
Published: January 2020

The gross morphology, fine structure, and per cent guanine plus cytosine (GC) composition of deoxyribonucleic acid of 27 strains of nitrifying bacteria were compared. Based on morphological differences, the ammonia-oxidizing bacteria were separated into four genera.
Nitrosomonas
species and
Nitrosocystis
species formed one homogenous group, and
Nitrosolobus
species and
Nitrosospira
species formed a second homogenous group in respect to their deoxyribonucleic acid GC compositions. Similarly, the nitrite-oxidizing bacteria were separated into three genera based on their morphology. The members of two of these nitrite-oxidizing genera,
Nitrobacter
and
Nitrococcus
, had similar GC compositions, but
Nitrospina gracilis
had a significantly lower GC composition than the members of the other two genera.
Complementary Functioning of Nitrogenase Components from a Blue-Green Alga and a Photosynthetic Bacterium
Authors: Smith R. V. , Telfer A. , Evans M. C. W.
Published: January 2020

Nitrogenases from
Anabaena cylindrica
and
Chloropseudomonas ethylicum
were partially purified into two components.
A. cylindrica
fraction I protein complemented fraction II protein from
C. ethylicum
. However, the reciprocal cross between
C. ethylicum
fraction I and
A. cylindrica
fraction II was negative.
Multivalent Repression and Genetic Derepression of Isoleucine-Valine Biosynthetic Enzymes in
Serratia marcescens
Authors: Kisumi Masahiko , Komatsubara Saburo , Chibata Ichiro
Published: January 2020

The regulation of the formation of isoleucine-valine biosynthetic enzymes was examined to elucidate the mechanism of isoleucine-valine accumulation by α-aminobutyric acid-resistant (
abu-r
) mutants of
Serratia marcescens
. In the isoleucine-valine auxotroph,
l
-threonine dehydratase, acetohydroxy acid synthetase, and transaminase B were repressed when isoleucine, valine, and leucine were simultaneously added to minimal medium. These enzymes were derepressed at the limitation of any single branched-chain amino acid. Pantothenate, which stimulated growth of this auxotroph, had no effect on the enzyme levels. It became evident from these results that in
S. marcescens
isoleucine-valine biosynthetic enzymes are subject to multivalent repression by three branched-chain amino acids. The
abu-r
mutants had high enzyme levels in minimal medium, with or without three branched-chain amino acids. Therefore, in
abu-r
mutants, isoleucine-valine biosynthetic enzymes are genetically derepressed. This derepression was considered to be the primary cause for valine accumulation and increased isoleucine accumulation.
Biochemistry of
Coxiella burnetii:
Embden-Meyerhof Pathway
Authors: McDonald Thomas L. , Mallavia L.
Published: January 2020

Purified preparations of
Coxiella burnetii
were examined for enzymes of the glycolytic pathway. Glucose-phosphate isomerase, fructose-1,6-diphosphatase, aldolase, glyceraldehyde-3-phosphate dehydrogenase, and pyruvate kinase were shown to be present in
C. burnetii
extracts. Heat-killed
C. burnetii
purified with normal yolk sacs demonstrated no activity after disruption. Aldolase was shown to be of the class II type by complete inhibition of activity in the presence of 8 × 10
−3
m
ethylenediaminetetraacetic acid. The host enzyme activity (normal and infected yolk sacs) was not affected by the same treatment. When cellulose acetate electrophoresis was performed on the extracts, aldolase from both normal and infected yolk sacs exhibited five isozyme bands, whereas aldolase from the
C. burnetii
extract appeared as a single band.
Nucleotide Metabolism During Differentiation in
Dictyostelium discoideum
Authors: Rutherford C. L. , Wright B. E.
Published: January 2020

Energy metabolism in
Dictyostelium discoideum
was studied by following the incorporation of [
3
H]adenine and [
32
P]Pi into the intracellular adenine nucleotides at two stages of differentiation. That the levels of nucleotides measured represented levels present in vivo was shown by demonstrating that the concentrations determined from cells quickly frozen in liquid nitrogen were identical to those from cells harvested and subsequently killed in perchloric acid. In addition, significant compartmentalization among the nucleoside triphosphates was not observed after 30 min, since uridine triphosphate, guanosine triphosphate, and adenosine triphosphate (ATP) were at radioactive equilibrium after exposure to [
32
P]Pi. At the sorocarp stage of differentiation, the dominant role of adenylate kinase activity is indicated by the observations that (i) adenylate kinase activity was found to be present, (ii) the specific radioactivities of the beta- and gamma-phosphates of ATP were equal, (iii) the increase in specific radioactivity of adenosine diphosphate was one-half that of ATP in the presence of [
32
P]Pi, and (iv) the steady-state equilibrium constant calculated (0.69) from the nucleotide levels equaled that of the apparent equilibrium constant reported in the literature (0.70). By using the same criteria, adenylate kinase activity was not the predominant reaction establishing the adenine nucleotide levels in cells at the pseudoplasmodium stage of differentiation.
Relationship Between Energy Substrate Utilization and Specific Growth Rate in
Aspergillus nidulans
Authors: Carter B. L. A. , Bull A. T. , Pirt S. J. , Rowley B. I.
Published: January 2020

The maintenance coefficient of glucose-limited
Aspergillus nidulans
chemostat cultures at 30 C was 0.018 g per g (dry weight) per hr for glucose and 0.55 mmoles per g (dry weight) per hr for oxygen. These values can only be approximate because melanin was produced by the mold at low growth rates and because it is unlikely that this polymer contributed to the maintenance energy requirement although it contributed to the dry weight. Biomass (defined here as dry weight minus melanin) was used to calculate a more meaningful maintenance coefficient for glucose (0.029 g of glucose per g of biomass per hr). At the highest growth rates examined, a nonlinear relationship between growth rate and glucose utilization rate was obtained, suggesting a qualitative change in the metabolic activities of the mold at high growth rates. The oxidative capacity of the mold was highest at the highest growth rates. This observation indicates that the increased substrate utilization rate observed at the higher growth rates is a reflection of enhanced enzyme synthesis. This hypothesis was verified by assaying the specific activities of several enzymes at different growth rates. However, in contrast to all the other enzymes assayed, the activities of reduced nicotinamide adenine dinucleotide phosphate: (acceptor) oxido-reductases were highest at the lowest growth rates.
Antibacterial Nitroacridine, Nitroakridin 3582: Effects on Bacterial Growth and Macromolecular Biosynthesis In Vivo
Authors: Wolfe Alan D. , Cook Thomas M. , Hahn Fred E.
Published: January 2020

The antibacterial drug Nitroakridin 3582 inhibited the growth of selected grampositive bacteria more strongly than it inhibited the growth of gram-negative bacilli. Nitroakridin at concentrations of the order of 5 × 10−5minduced lysis ofBacillus licheniformisandMicrococcus lysodeikticus. At concentrations less than 10−4m, Nitroakridin 3582 reduced the exponential growth rate ofEscherichia coliC-2; at 10−4mthe drug was bacteriostatic, and, at concentrations greater than 10−4m, it was bactericidal. Prolonged bacteriostasis resulted in the formation of long filaments byE. coli, Serratia marcescens, Shigella sonnei, andProteus mirabilis. The reversible effects of Nitroakridin 3582 on the growth ofE. colicorrelated with partial inhibitions of deoxyribonucleic acid biosynthesis; ribonucleic acid and protein syntheses were inhibited less strongly. Nitroakridin 3582 at concentrations greater than 2 × 10−4m, which block deoxyribonucleic acid biosynthesis, produced an accelerated bactericidal action.
Nature of the Penetration Barrier inEscherichia coliK-12: Effect of Macromolecular Inhibition on Penetrability in Strains Containing theenvAGene
Authors: Normark Staffan , Westling Britta
Published: January 2020

TheenvAmutation inEscherichia coliK-12, which maps at 1.5 min, was previously shown to mediate sensitivity to gentian violet as well as to several antibiotics. Moreover, strains containing theenvAgene were recently found to be lysed by lysozyme in the absence of ethylenediaminetetraacetate. It is here reported that theenvAmutation mediates an increased uptake of gentian violet. The uptake of the dye was markedly affected by growth with different antibiotics interfering with macromolecular synthesis. Amino acid starvation of a strain containingenvAwith a stringent control of ribonucleic acid (RNA) synthesis resulted in a decreased uptake of gentian violet. However, no decrease in dye uptake was found during starvation in anenvAtransductant with a relaxed control of RNA synthesis. Inhibition of deoxyribonucleic acid (DNA) synthesis by nalidixic acid decreased the uptake of gentian violet ofenvAcells and, in addition, rendered the cells insensitive to the lytic action of lysozyme. Chloramphenicol treatment increased penetrability in wild-type and starvedenvAcells. In most instances, this effect of chloramphenicol was prevented by selectively interfering with DNA or RNA synthesis. A coordinate regulation of nucleic acid synthesis and penetrability is suggested.
Antimicrobial Actions of Hexachlorophene: Release of Cytoplasmic Materials
Authors: Joswick H. L. , Corner Thomas R. , Silvernale J. N. , Gerhardt Philipp
Published: January 2020

Intracellular solutes were released from growing or resting cells of
Bacillus megaterium
as a consequence of hexachlorophene treatment. The effect was dose dependent, with the optimum at a concentration about sevenfold greater than the minimal lethal dose. The effects of
p
H and temperature on the leakage process also were inconsistent with the killing effects of the drug. The types of materials released appeared to be the same with or without hexachlorophene treatment. The released materials were small molecules which apparently derived from preexisting ribonucleic acid and protein, but not from deoxyribonucleic acid. Compared to the effects of other representative surface-active agents and other bis-phenols, hexachlorophene was superior in ability to cause leakage of intracellular materials. Different microorganisms varied in their susceptibility to hexachlorophene, with
Pseudomonas aeruginosa
and a paracolon isolate the most resistant of the vegetative cells examined. It was concluded that the release of intracellular solutes was an effect secondary to the lethal event and presumably arose from hexachlorophene-mediated stimulation of degradative enzymes.
Effect of Ethylenediaminetetraacetic Acid, Triton X-100, and Lysozyme on the Morphology and Chemical Composition of Isolated Cell Walls of
Escherichia coli
Authors: Schnaitman Carl A.
Published: January 2020

Extraction of a partially purified preparation of cell walls from
Escherichia coli
with the nonionic detergent Triton X-100 removed all cytoplasmic membrane contamination but did not affect the normal morphology of the cell wall. This Triton-treated preparation, termed the “Triton-insoluble cell wall,” contained all of the protein of the cell wall but only about half of the lipopolysaccharide and one-third of the phospholipid of the cell wall. This Triton-insoluble cell wall preparation was used as a starting material in an investigation of several further treatments. Reextraction of the Triton-insoluble cell wall with either Triton X-100 or ethylenediaminetetraacetic acid (EDTA) caused no further solubilization of protein. However, when the Triton-insoluble cell wall was extracted with a combination of Triton X-100 and EDTA, about half of the protein and all of the remaining lipopolysaccharide and phospholipid were solubilized. The material which remained insoluble after this combined Triton and EDTA extraction still retained some of the morphological features of the intact cell wall. Treatment of the Triton-insoluble cell wall with lysozyme resulted in a destruction of the peptidoglycan layer as seen in the electron microscope and in a release of diaminopimelic acid from the cell wall but did not solubilize any cell wall protein. Extraction of this lysozyme-treated preparation with a combination of Triton X-100 and EDTA again solubilized about half of the cell wall protein but resulted in a drastic change in the morphology of the Triton-EDTA-insoluble material. After this treatment, the insoluble material formed lamellar structures. These results are interpreted in terms of the types of noncovalent bonds involved in maintaining the organized structure of the cell wall and suggest that the main forces involved are hydrophobic protein-protein interactions between the cell wall proteins and to a lesser degree a stabilization of protein-protein and protein-lipopolysaccharide interactions by divalent cations. A model for the structure of the
E. coli
cell wall is presented.
Alterations in the Cytoplasmic Membrane Proteins of Various Chlorate-Resistant Mutants of
Escherichia coli
Authors: MacGregor C. H. , Schnaitman C. A.
Published: January 2020

Chlorate-resistant mutants corresponding to each known genetic locus (
chlA, chlB, chlC, chlD, chlE
) were isolated from
Escherichia coli
K-12. All these mutants showed decreased amounts of membrane-bound nitrate reductase, cytochrome
b
, and formic dehydrogenase, but all had normal succinic dehydrogenase activity. Proteins from the cytoplasmic membranes of these mutants were compared to those of the wild type-on polyacrylamide gels. The addition of nitrate to wild-type anaerobic cultures caused increased formation of three membrane proteins. These same proteins, along with one other, were missing in varying patterns in mutants altered at the different genetic loci. One of the missing proteins was found to be the enzyme nitrate reductase, although this protein was present in some mutants lacking nitrate reductase activity. None of the others has been identified.
Isolation, Mapping, and Characterization of Trehalaseless Mutants of
Neurospora crassa
Authors: Sussman Alfred S. , Garrett M. Kerry , Sargent Malcolm , Yu Shih-An
Published: January 2020

Mutant strains of
Neurospora crassa
that lack trehalase and are unable to grow on trehalose were isolated, and the gene (
tre
) was positioned on the right arm of linkage group I. Maltase and β-galactosidase activities are almost identical in
tre
−
strains, whereas that of invertase was reduced by more than half and those of acid phosphatase and amylase were somewhat increased. Heterocaryons between standard and trehalaseless strains yield less than one-tenth the activity of the former. In addition, strains with duplications heterozygous for trehalase produce less than 1% of the activity of the standard strain. An inhibitor of trehalase has been found in
tre
−
strains; its sensitivity to heat and proteolysis, and its nondialyzability suggest that this substance is a protein. The
mig
gene, which determines the rate of migration of trehalase on acrylamide gels, has been shown to be less than 1 map unit away from the
tre
gene.
Complementation and Genetic Recombination in
Candida lipolytica
Authors: Bassel John , Warfei Jean , Mortimer Robert
Published: January 2020

Nutritional requirements were introduced into wild-type, heterothallic strains of
Candida lipolytica
by exposing the cells to X rays. Complementing hybrids were recovered from mixtures of the auxotrophic strains, and genetic recombination was observed in individually isolated ascospores from the hybrid strains.
Synthesis and Some Properties of an Actin-Like Nuclear Protein in the Slime Mold
Physarum polycephalum
Authors: Jockusch Brigitte M. , Brown Donna F. , Rusch Harold P.
Published: January 2020

A protein was extracted from isolated nuclei of the slime mold
Physarum polycephalum
which could be labeled with radioactive precursors only during G
2
phase. The native protein was purified by extraction in low-ionic-strength buffer [10 m
m
tris(hydroxymethyl)aminomethane-hydrochloride] of isolated nuclei and by preparative polyacrylamide gel electrophoresis. It was extracted from isolated nucleoli. Its electrophoretic properties in three different polyacrylamide gel systems, its molecular weight (44,000 ± 3,000), its precipitability by vincaleucoblastine, a vinca alkaloid, and its aggregation properties suggested that it might be actin. In a direct comparison with slime mold actin purified from the cytoplasm, no difference could be found between the two proteins in all these characteristics. The synthesis of cytoplasmic actin was not found to occur exclusively during G
2
phase. This suggested that nuclear actin was either synthesized independently from cytoplasmic actin or transported into the nuclei exclusively during G
2
phase. The possible role of nuclear actin during intranuclear mitosis is discussed.
Phosphorolysis of 5-Fluoro-2′-Deoxyuridine in
Escherichia coli
and Its Inhibition by Nucleosides
Authors: Yagil Ezra , Rosner Arie
Published: January 2020

The effect of ribonucleosides and deoxyribonucleosides on the phosphorolysis of 5-fluoro-2′-deoxyuridine (FUdR) was examined in cells of
Escherichia coli
. All nucleosides tested except guanosine and deoxyguanosine inhibited phosphorolysis. By using genetically marked strains it was found that in vivo FUdR is a specific substrate of thymidine phosphorylase.
Physiology of Sporeforming Bacteria Associated with Insects IV. Glucose Catabolism in
Bacillus larvae
Authors: Julian Grant St. , Bulla Lee A.
Published: January 2020

Bacillus larvae
appears to be unique among related bacilli in that it contains enzymes of the Embden-Meyerhof-Parnas, pentose phosphate, and Entner-Doudoroff pathways. Simultaneous occurrence of enzymes of all three metabolic pathways has not until now been reported in other
Bacillus
species. Radiorespirometric analyses of specifically labeled glucose catabolism reveal that vegetative cells of
B. larvae
dissimilate glucose predominately via a direct oxidative route and to a lesser extent by a nonoxidative scheme although specific activities of enzymes of all three pathways are comparable. Predominance of an oxidative pathway is unusual and also has not been reported for other bacilli. Studies on the oxidation of pyruvic, acetic, succinic, and α-ketoglutaric acids show that terminal respiration of cells in transition from vegetative growth to sporulation involves both the tricarboxylic acid and glyoxylic acid cycles. The relationship of these findings to the fastidiousness and oligosporogeny of
B. larvae
is discussed.
Stimulation of Ribonucleic Acid Synthesis by Chloramphenicol in a
rel
+
Aminoacyl-Transfer Ribonucleic Acid Synthetase Mutant of
Escherichia coli
Authors: Yegian Charles D. , Vanderslice Rebecca W.
Published: January 2020

Escherichia coli
strain 9D3 possesses a highly temperature-sensitive valyl-transfer ribonucleic acid (tRNA) synthetase (EC 6.1.1.9). Since 9D3 is a
rel
+
strain, it cannot carry out net RNA synthesis at high temperature. A 100-μg amount of chloramphenicol (CAP) per ml added in the absence of valine cannot stimulate RNA synthesis. Either 300 μg of CAP or 100 μg of CAP plus 50 μg of valine per ml, however, promotes nearly maximal RNA synthesis. These results can be understood as follows. (i) Valyl-tRNA is required for net RNA synthesis, (ii) the synthetase lesion is incomplete, (iii) the rate of mutant acylation of tRNA
val
at high temperature is valine-dependent, and (iv) the CAP concentration determines the rate of residual protein synthesis. Data are also presented which demonstrate that the rate of net RNA synthesis can greatly increase long after the addition of CAP, if the amount of valyl-tRNA increases.
Activation of
Clostridium botulinum
Type B Toxin by an Endogenous Enzyme
Authors: DasGupta Bibhuti R.
Published: January 2020

It was previously postulated, based on indirect evidence, that
Clostridium botulinum
type B produces neurotoxin which is initially of low toxicity but which then becomes activated to highly toxic form by the action of an endogenous enzyme(s). The first direct in vitro experimental evidence in support of this hypothesis is presented here. The mildly active toxin (progenitor toxin) produced by
C. botulinum
type B (Lamanna) was isolated from the filtrate of a 24-hr culture and partially purified chromatographically. An enzyme that activates the progenitor toxin was also isolated from the filtrate of a 96-hr culture and purified 200-fold. The enzyme hydrolyzes synthetic substrates of trypsin but not of chymotrypsin.
Consequences of the Inhibition of Cardiolipin Metabolism in
Haemophilus parainfluenzae
Authors: Ono Yoshie , White David C.
Published: January 2020

Examination of phospholipid metabolism in
Haemophilus parainfluenzae
with inhibitors of various cellular functions indicated that macromolecular synthesis and lipid metabolism can be dissociated at least for a short time. Two classes of inhibitors have relatively specific effects on cardiolipin (CL) metabolism. Pentachlorophenol and
p
-hydroxymercuribenzoate blocked CL synthesis but allowed CL hydrolysis to phosphatidic acid and phosphatidyl glycerol (PG); 3,3′,4,5′-tetrachlorosalicylanilide (TCS) and carbonyl cyanide
m
-chlorophenylhydrazone (
m
-CCCP) blocked CL hydrolysis with the stoichiometric accumulation of CL. It appeared as if TCS and
m
-CCCP inhibited a vital activity coupled with the hydrolysis of CL by the highly active, CL-specific phospholipase D found in this organism. Because TCS and
m
-CCCP are thought to act by destroying the proton gradient thereby interrupting energy-dependent transport, it is possible that a highly active portion of the cellular CL could be coupled to some phase of this process.
Cyanide-Resistant Respiration in
Neurospora crassa
Authors: Lambowitz Alan M. , Slayman Carolyn W.
Published: January 2020

Cell respiration in wild type and
poky
was studied as part of a long-term investigation of cyanide-resistant respiration in
Neurospora
. Respiration in wild type proceeds via a cytochrome chain which is similar to that of higher organisms; it is sensitive to antimycin A or cyanide.
Poky
, on the other hand, respires by means of two alternative oxidase systems. One of these is analogous to the wild-type cytochrome chain in that it can be inhibited by antimycin A or cyanide; this system accounts for as much as 15% of the respiration of
poky
f
−
and 34% of the respiration of
poky
f
+
. The second oxidase system is unaffected by antimycin A or cyanide at concentrations which inhibit the cytochrome chain maximally. It can, however, be specifically inhibited by salicyl hydroxamic acid. The cyanide-resistant oxidase is not exclusive to
poky
, but is also present in small quantities in wild type grown under ordinary circumstances. These quantities may be greatly increased (as much as 20-fold) by growing wild type in the presence of antimycin A, cyanide, or chloramphenicol.
Inducible and Constitutive β-Galactosidase Formation in Cells Recovering from Protein Synthesis Inhibition
Authors: Soreq Hermona , Kaplan Ruth
Published: January 2020

Inducible and constitutive β-galactosidase formation and radioactive amino acid incorporation were measured in cells recovering from various treatments which inhibit protein synthesis in the cell. Undelayed β-galactosidase formation was found in stringent auxotrophs recovering from amino acid starvation, in cells recovering from glycerol or potassium starvation, and in bacteria recovering from puromycin treatment. Delayed β-galactosidase formation was found in relaxed auxotrophs recovering from amino acid starvation and in prototrophs recovering from chloramphenicol or from tetracycline treatment. The length of this delay was directly proportional to the duration of the treatment. All cells recovering from the various treatments exhibited a slightly decreased rate of β-galactosidase formation and an increase in radioactive amino acid incorporation.
Resistance ofEscherichia colito Penicillins IX. Genetics and Physiology of Class II Ampicillin-Resistant Mutants That Are Galactose Negative or Sensitive to Bacteriophage C21, or Both
Authors: Eriksson-Grennberg Kerstin G. , Nordström Kurt , Englund Per
Published: January 2020

Ampicillin-resistant mutants of class II are determined by a doubling of chromosomally and episomally mediated ampicillin resistance on agar plates. Several mutants were isolated from a female as well as from an Hfr strain. The mutants differed from each other in various properties such as response to colicin E2 and sodium cholate, response to the phages T4 and C21, and fermentation of galactose. By conjugation and transduction experiments, it was shown that mutations in at least four loci gave the class II phenotype. The mutations were found to be in thegalUgene, thectrgene, and two new genes close tomtldenotedlpsAandlpsB. The carbohydrate compositions of the lipopolysaccharides of the mutants were investigated and found to be changed compared to the parent strains.GalUmutants lacked rhamnose and galactose and had 11% glucose compared to the parent strain. ThelpsAmutant also lacked rhamnose and had only traces of galactose and 58% glucose, whereas thelpsBmutant contained 14% rhamnose, traces of galactose, and 81% glucose compared to the parent strain.
Effects of Adenosine 3′,5′-Monophosphate and Adenosine 5′-Monophosphate on Glycogen Degradation and Synthesis in
Dictyostelium discoideum
Authors: Rosness Per A. , Gustafson Gary , Wright Barbara E.
Published: January 2020

Data are presented demonstrating that the presence in vivo of adenosine 3′,5′-monophosphate (3′,5′-AMP) causes a rapid depletion of glycogen storage material in the cellular slime mold. The effect of adenosine 5′-monophosphate (5′-AMP) is twofold, stimulating both glycogen degradation and synthesis. In pseudoplasmodia, cell-free extracts appear to contain at least two species of glycogen phosphorylase, one of which is severely inhibited by glucose-1-phosphate and another which is only partially inhibited by this hexose-phosphate. In some cases, 5′-AMP partially overcomes the inhibition by glucose-1-phosphate. Data presented here also indicate the existence of two forms of glycogen synthetase, the total activity of which does not change during 10 hr of differentiation from aggregation to culmination. During this period there is a quantitative conversion of glucose-6-phosphate–independent enzyme activity to glucose-6-phosphate–dependent activity. It is suggested that one effect of 3′,5′-AMP is closely related to enzymatic processes involved in the rapid conversion of glycogen to cell wall material and other end products accumulating during sorocarp construction.
Properties and Mode of Action of a Bactericidal Compound (= Methylglyoxal) Produced by a Mutant of
Escherichia coli
Authors: Krymkiewicz Norberto , Diéguez Eugenia , Rekarte Usua D. , Zwaig Noé
Published: January 2020

A lethal product (BPG) produced by a glycerol kinase mutant of
Escherichia coli
was purified, and its mode of action on
E. coli
was studied. At concentrations where BPG strongly inhibits in vivo deoxyribonucleic acid, ribonucleic acid, and protein synthesis, it produces small effects on other functions: slight inhibition of respiration and small changes in intracellular pools of substrates, nucleic acids degradation, and adenosine triphosphate levels. BPG also inhibits in vitro protein synthesis and produces inactivation of bacteriophage T4. The bactericidal product has been identified in another laboratory as methylglyoxal (MG). By comparing BPG and MG, we confirmed this observation and concluded that the activity found in our BPG preparation is due to its MG content. We also observed that MG is able to react with guanosine triphosphate. According to these results, it is interpreted that MG could act directly on macromolecular synthesis by reacting with the guanine residues of nucleic acids and its precursors.
Taxonomy of Marine Bacteria:
Beneckea nigrapulchrituda
sp. n
Authors: Baumann Paul , Baumann Linda , Mandel M. , Allen Richard D.
Published: January 2020

Fourteen bacterial strains of marine origin, which formed colonies containing crystals of a blue-black pigment, were submitted to a morphological, physiological, and nutritional characterization. The results indicated that these organisms form a new species of the genus
Beneckea
.
Genetic Determinant in
Escherichia coli
Affecting Thymineless Death and Ultraviolet Sensitivity
Authors: Wilkins A. , Gallant J. , Harada B.
Published: January 2020

We have infected
Escherichia coli
strain B3 with F′ factors carrying different lengths of the K-12 chromosome. When the F′ factor carries the
tsx
to
purE
segment, the resulting hybrid merodiploid shows increased sensitivity to thymineless death, although leaky deoxyribonucleic acid synthesis is unaffected, as well as increased sensitivity to ultraviolet irradiation. The dominant or partially dominant character of the effect indicates that it is not a product of allelic differences between
E. coli
K and B at either
ras
or
lon
.
Caffeic Acid Metabolism by Bacteria of the Human Gastrointestinal Tract
Authors: Peppercorn Mark A. , Goldman Peter
Published: January 2020

The metabolism of caffeic acid, previously shown to be carried out by the intestinal microbiota of man and experimental animals, has now been examined in a number of bacteria isolated from human feces. It has been found that of the 12 organisms isolated none has the ability to catalyze more than one reaction of the series leading from caffeic acid to either
m
-hydroxyphenylpropionic acid or 4-ethylcatechol.
Phenotype of a Temperature-Sensitive, Respiration-Deficient (
cyt
) Mutant of Yeast
Authors: Miyake Setsuko , Iwamoto Yoshihisa , Nagao Minako , Sugimura Takashi , Ohsumi Masako
Published: January 2020

A temperature-sensitive respiration-deficient mutant of yeast lacks hemoproteins and accumulates coproporphyrin III when cultivated at elevated temperatures. Cells grown at 20 C respired normally and contained cytochromes
a, b
, and
c
. Cells grown at 35 C showed respiration-deficient mutant characters; they did not respire, lacked cytochromes, and accumulated coproporphyrin III. Addition of protoporphyrin IX or protohemin IX to the culture medium restored the respiratory activity of this mutant during growth at 35 C. The activities of various enzymes, including succinate-2,6-dichlorophenol indophenol (DCPIP), reduced nicotinamide adenine dinucleotide (NADH
2
)-DCPIP, succinate-cytochrome
c
, and NADH
2
-cytochrome
c
oxidoreductase, and cytochrome oxidase, and the cytochrome
c
content of cells cultured in various conditions were determined. Changes in the number and structure of mitochondria were associated with changes in respiratory activity.
Interaction of Maltose Transport with the Transport of Glucose and Galactosides
Authors: McKinstry Grenetta , Koch Arthur L.
Published: January 2020

In cells of
Escherichia coli
possessing both maltose and galactoside permease, fluxes via one permease are independent of the substrate for the other permease. However, both fluxes are partially inhibited by glucose or α-methyl glucoside at low concentrations in cells grown on glucose. Neither maltose nor galactosides have an inhibitory effect on glucose permease function. These observations are consistent with the hypothesis that the number of glucose permease systems on the cell surface of such cells is much larger than the number for maltose or galactosides.
Chemical and Physical Characteristics of the Deoxycholate-Soluble and Magnesium-Reaggregated Membrane Nicotinamade Adenine Dinucleotide (Reduced Form) Oxidase of
Bacillus megaterium
Authors: Yu L. , Wolin M. J.
Published: January 2020

The inactive components of the nicotinamide adenine dinucleotide (reduced form) (NADH) oxidase present in the 0.4% deoxycholate-soluble fraction obtained from
Bacillus megaterium
KM membranes were reaggregated into active NADH oxidase by dilution in the presence of Mg
2+
. The reaggregated oxidase was different from the original membrane with respect to sedimentation behavior in a sucrose gradient and morphological appearance. The deoxycholate-insoluble portion of the membrane had membrane-like structure whereas the reaggregated oxidase appeared to be a filamentous aggregate of small particles. The reaggregated oxidase and the deoxycholate-insoluble membrane residue were similar to the original membrane with respect to total protein and total lipid content. The inactive components of the NADH oxidase system exist in deoxycholate as two molecular species which were separable by sucrose density gradient centrifugation or gel filtration in deoxycholate-containing solutions. Both components and dilution in the presence of Mg
2+
were necessary for restoration of oxidase activity. The smaller-molecular-weight component contained all of the NADH-2,6-dichlorophenolindophenol oxidoreductase activity of the original membrane.
Distribution of Lipids in the Wall and Cytoplasmic Membrane Subfractions of the Cell Envelope of
Escherichia coli
Authors: White David A. , Lennarz W. J. , Schnaitman Carl A.
Published: January 2020

Cell wall and membrane subfractions of the cell envelope of
Escherichia coli
have been isolated by a procedure involving particle electrophoresis and sucrose gradient density centrifugation. The lipid content of each fraction has been investigated. The individual phospholipids of both fractions are quantitatively similar except that the proportion of lysophosphatidylethanolamine is greater in the wall than in the membrane. Fatty acid analysis of the phospholipids of each fraction revealed that the wall phospholipids contain a greater proportion of palmitic acid. Coenzyme Q is almost exclusively localized in the cell membrane.
Genetic Control of Enzyme Induction in the β-Ketoadipate Pathway ofPseudomonas putida:Deletion Mapping ofcatMutations
Authors: Wheelis M. L. , Ornston L. N.
Published: January 2020

A number of spontaneous mutant strains ofPseudomonas putida, obtained by repeated selection for inability to grow withcis,cis-muconate, have been shown to carry deletions incatB, the structural gene for muconate lactonizing enzyme. These strains have been employed for deletion mapping of the genetic region containingcatBandcatC(the structural gene for muconolactone isomerase, the synthesis of which is coordinate with that of muconate lactonizing enzyme). All deletions that overlap mutant sites located on the left side of the genetic map, as well as the point mutations in that region, lead to a pleiotropic loss of bothcatBandcatCactivities. We propose that this region to the left ofcatBhas a regulatory function. Although the details of regulation at the molecular level are unclear, our data indicate thatcatBandcatCmay well be controlled by a mechanism unlike any yet described by workers on enteric bacteria.
Genetic Control of Enzyme Induction in the β-Ketoadipate Pathway of
Pseudomonas putida:
Two-Point Crosses with a Regulatory Mutant Strain
Authors: Wu C.-H. , Ornston M. K. , Ornston L. N.
Published: January 2020

Several mutant strains of
Pseudomonas putida
, selected on the basis of their inability to grow at the expense of benzoate, have been shown to be unable to form inducibly both muconate lactonizing enzyme and muconolactone isomerase. A secondary mutant strain derived from one of these pleiotropically negative strains forms these two enzymes and, in addition, catechol oxygenase in the absence of inducer. This constitutive mutant strain was used as a donor in transductionally mediated two-point crosses to determine the order of point mutations within the structural genes for muconate lactonizing enzyme and muconolactone isomerase (the
catB
and
catC
genes, respectively). The gene order conformed precisely with the one that has been established by deletion mapping.
Cell Cycle Dependency of Sporulation in
Saccharomyces cerevisiae
Authors: Haber James E. , Halvorson Harlyn O.
Published: January 2020

The study of sporulation in
Saccharomyces cerevisiae
is complicated by the fact that not all cells in the population complete sporulation and that the kinetics of development of those which do are not synchronous. By separating vegetative cells by zonal rotor centrifugation into fractions of increasing cell volume and hence progressive stages of the vegetative cell cycle, it was possible to observe sporulation of more homogeneous, synchronous populations. The capacity of
S. cerevisiae
to complete sporulation is low for small single cells at the beginning of the cell cycle and is greatest for large budded cells about to divide. The capacity of a cell to complete sporulation thus appears to be directly related to the stage in the vegetative cell cycle from which it was taken. The use of synchronously sporulating cultures made it possible to examine very early decision events leading to the commitment of a cell to sporulation. In addition, differences in the capacity of a mother and daughter cell produced by cell scission were examined.
Chemical Analysis of and Degradation Studies on the Cell Wall Lipopolysaccharide of
Rhodopseudomonas capsulata
Authors: Weckesser J. , Drews G. , Fromme I.
Published: January 2020

A lipopolysaccharide (LPS) has been isolated from the gram-negative photosynthetic bacterium
Rhodopseudomonas capsulata
. Chemical analysis revealed the presence of
d
-glucose,
d
-galactose,
l
-rhamnose, 3-
O
-methyl-
l
-rhamnose (
l
-acofriose),
d
-glucosamine, 2-keto-3-deoxyoctonate, and neuraminic acid. The LPS does not contain
l
-glycero-
d
-mannoheptose, a typical component of the LPS of enteric bacteria. Fatty acid analysis showed that, apart from lauric acid, two hydroxy fatty acids (hydroxycaproic and hydroxymyristic acids) are the main components. By hydrolysis in weak acid, the LPS has been separated into a polysaccharide part (degraded polysaccharide) and a lipid part (lipid A). Presumably the lipid A contains a glucosamine backbone. Whereas the OH-groups of glucosamine are esterified with lauric and hydroxycaproic acids, hydroxymyristic acid is linked to the amino group of the sugar. By separation of the degraded polysaccharide by gel filtration, a fraction has been isolated which inhibited hemagglutination in a system containing antiserum, obtained by immunization of rabbits with whole cells, and isolated LPS. This fraction, which includes the determinant group, contains the sugars glucose, rhamnose, and acofriose. A second fraction obtained in this way was found to be serologically inactive and is composed of glucose, galactose, neuraminic acid, and phosphate.
Growth of Obligate Autotrophic Bacteria on Glucose in a Continuous Flow-Through Apparatus
Authors: Pan P. , Umbreit W. W.
Published: January 2020

Nitrosomonas europaea, Nitrobacter agilis, Thiobacillus denitrificans, T. neapolitanus
, and
T. thioparus
(all obligate autotrophic bacteria) have been grown in dialysis culture, on glucose salts media, in the absence of their specific inorganic energy source. Metabolic products for
N. agilis
grown on nitrite salts medium were identified as keto acids. Pyruvic acid inhibited this organism at 5 × 10
−5
m
. Keto acids were not inhibitory for the thiobacilli grown on thiosulfate medium. However, when
T. denitrificans
was grown on glucose with dialysis, addition of 5 × 10
−4
m
pyruvate inhibited growth. Thus, it appears pyruvate may be inhibitory for other autotrophs, as has been reported for
T. thiooxidans
.
Freeze-Etching of
Azotobacter vinelandii:
Examination of Wall, Exine, and Vesicles
Authors: Cagle Gerald D. , Vela G. R. , Pfister Robert M.
Published: January 2020

The structure of the cell wall, the arrangement of the cyst exine, and the origin and distribution of intine vesicles in
Azotobacter vinelandii
ATCC 12837 were examined by freeze-etching and conventional electron microscopic techniques. In the vegetative organism the cell wall appears to have a woven texture which disappears during cyst formation. The exine is composed of two different types of material: the outer layer is a fibrous, amorphous layer, and the numerous inner layers form the basic hexagonal structures which unite to form the cyst coat. The presence of intine vesicles in the encysting organism was confirmed in frozen-etched cells. The appearance of frozen-etched cells and cysts and the distribution of capsular material indicate that extracellular polysaccharide is an important factor in cyst formation.
Action of Haemophilus Endodeoxyribonuclease on Biologically Active Deoxyribonucleic Acid
Authors: Gromkova Rosa , Goodgal Sol H.
Published: January 2020

An enzyme similar to that described by Smith and Wilcox (15) for
Haemophilus influenzae
which attacks foreign deoxyribonucleic acid (DNA) but not its own has been isolated and purified from
H. parainfluenzae
. The enzyme degrades foreign DNA to limited sizes and can destroy the transforming activity of
H. influenzae
and
Bacillus subtilis
DNA. The enzyme can also destroy the biological activity of
H. influenzae
phage and prophage DNA. On the other hand, the
H. influenzae
endodeoxyribonuclease can destroy the transforming activity of
H. parainfluenzae
DNA but not its own DNA. It also attacks
B. subtilis
DNA and its transforming activity.