bluuebunny/crossref_metadata_2025 huggingface dataset:
Distribution of the Phosphoenolpyruvate:Glucose Phosphotransferase System in Bacteria
Authors: Romano Antonio H. , Eberhard Susan J. , Dingle Sharon L. , McDowell Thomas D.
Published: January 2020

A survey of the occurrence of the phosphoenolpyruvate-dependent glucose phosphotransferase system was carried out in a number of bacteria, representing both gram-positive and gram-negative facultative anaerobic and strictly aerobic types. The system was found to be present in representatives of genera that are characteristically facultative anaerobes, but the system was absent in members of those genera that are strictly aerobic. Thus, although the phosphoenolpyruvate phosphotransferase system is an important system for the transport of sugars in bacteria carrying out anaerobic glycolysis, it plays no role in sugar transport by those organisms having a strictly oxidative physiology. A fundamentally different system, probably not involving phosphorylation during transport, is indicated in this latter group.
Metabolism of
l
-Malate and
d
-Malate by a Species of
Pseudomonas
Authors: Hopper D. J. , Chapman P. J. , Dagley S.
Published: January 2020

Extracts of a fluorescent species of
Pseudomonas
grown with
m
-cresol, degrade gentisic acid without isomerization of the ring-fission compound, maleylpyruvate, to give eventually
d
-malate and pyruvate.
d
-Malate is also a growth substrate.
l
-Malate but not
d
-malate is oxidized by a particulate enzyme not requiring nicotinamide adenine dinucleotide (NAD) or nicotinamide adenine dinucleotide phosphate (NADP). NAD- or NADP-linked malate dehydrogenases are absent but cells contain an NADP-dependent
l
-malic enzyme. Exposure of cells to exogenous
d
-malate induces an NAD-dependent
d
-malic enzyme, not present when
d
-malate is formed endogenously. Succinate- or
m
-cresol-grown cells, containing no
d
-malic enzyme, rapidly oxidize
d
-malate in the presence of chloramphenicol at a concentration suffient to inhibit protein synthesis. An NADP-dependent cell-free system, prepared from succinate-grown cells which oxidized
d
-malate, is described.
Membrane Mg
2+
-(Ca
2+
)-Activated Adenosine Triphosphatase of
Escherichia coli
: Characterization in the Membrane-Bound and Solubilized States
Authors: Evans Doyle J.
Published: January 2020

The membrane-associated Mg
2+
-activated and Ca
2+
-activated adenosine 5′-triphosphatase (EC 3.6.1.3; ATPase) activities of
Escherichia coli
were further characterized. The degree of inhibition of membrane-bound Mg
2+
-(Ca
2+
)-ATPase by a series of anions (i.e., sodium salts of nitrate, iodide, chloride, and acetate) was found to correlate with the relative chaotropic, or solubilizing, effectiveness of these anions. The enzyme was solubilized from washed membrane ghosts by treatment with 0.04% sodium lauryl sulfate at
p
H 9.0 and 37 C. Solubilized Mg
2+
-(Ca
2+
)-ATPase exhibited an initial increase in activity, followed by fairly rapid inactivation, both ATPase activities being particularly cold-labile. The combined stabilizing effects of lauryl mercaptan (1-dodecanethiol), 0.01
m
tris(hydroxymethyl)amino-methane-hydrochloride buffer (
p
H 9.0), 0.2 m
m
MgCl
2
, and ambient temperature facilitated partial purification of the enzyme, the molecular weight of which was estimated to be approximately 100,000 by the gel filtration technique. In general, the membrane-associated Mg
2+
-(Ca
2+
)-ATPase of
E. coli
resembles both mitochondrial membrane ATPase and the well-characterized membrane ATPases of
Bacillus megaterium
and
Microcococcus lysodeikticus
. It is of particular interest that
N,N
′-dicyclohexylcarbodiimide (DCCD), a known inhibitor of mitochondrial ATPase, of mitochondrial oxidative phosphorylation, and of the membrane-bound Mg
2+
-ATPase of
Streptococcus faecalis
was found to inhibit both the membrane-bound and the solubilized forms of
E. coli
Mg
2+
-(Ca
2+
)-ATPase. The sensitivity of the membrane-associated Mg
2+
-(Ca
2+
)-ATPase of
E. coli
to both anions and cations, its allotopic behavior, and its susceptibility to inhibition by DCCD favor the idea that this enzyme plays a key, probably polyfunctional, role in such biological activities of the membrane as oxidative phosphorylation and ion transport.
Vegetative Replication and Transfer Replication of Deoxyribonucleic Acid in Temperature-Sensitive Mutants of
Escherichia coli
K-12
Authors: Marinus M. G. , Adelberg E. A.
Published: January 2020

Crosses were carried out at 34 C and 42 C between eight pairs of isogenic strains of
Escherichia coli
K-12. The donor and recipient of each pair carried the same mutation for temperature-sensitive deoxyribonucleic acid (DNA) synthesis; they differed only in the presence of F-
lac
in the donor and a spectinomycin-resistance marker in the recipient. A different temperature-sensitive mutation was present in each of the eight pairs, the eight temperature-sensitive mutations being located in at least two different genes. In all eight pairs, the transfer of F-
lac
occurred at high and equal rates at 34 C and 42 C, although vegetative DNA replication at 42 C was approximately 10
−4
of that at 34 C. The transfer of F-
lac
at 42 C was accompanied in seven of the eight crosses by an equivalent amount of DNA synthesis in excess of that observed in the unmated controls. The DNA synthesized during transfer at 42 C was characterized by equilibrium centrifugation in cesium chloride and by its sedimentation velocity in sucrose gradients. It was found to have a density and a molecular weight characteristic of F-
lac
DNA. A small proportion of the material labeled during transfer was recovered in the form of covalently closed DNA. It is concluded that vegetative replication of the chromosome and transfer replication of F are separate processes, the former requiring at least two gene products which are nonessential for the latter.
Manganese Active Transport in
Escherichia coli
Authors: Silver Simon , Johnseine Paula , King Karen
Published: January 2020

Manganese was accumulated by cells of
Escherichia coli
by means of an active transport system quite independent of the magnesium transport system. When the radioisotope
54
Mn was used, manganese transport showed saturation kinetics with a
K
m
of 2 × 10
−7
m
and a
V
max
of 1 to 4 nmoles/min per 10
12
cells at 25 C. The manganese transport system is highly specific; magnesium and calcium did not stimulate, inhibit, or compete with manganese for cellular uptake. Cobalt and iron specifically interfered with
54
Mn uptake, but only when added at concentrations 100 times higher than the
K
m
for manganese. Active transport of manganese is temperature- and energy-dependent: uptake of
54
Mn was inhibited by cyanide, dinitrophenol, and
m
-chlorophenyl carbonylcyanide hydrazone (CCCP). Furthermore, the turnover or exit of manganese from intact cells was inhibited by energy poisons such as dinitrophenol and CCCP.
Factors Affecting Transformation of
Pasteurella novicida
Authors: Tyeryar Franklin J. , Lawton William D.
Published: January 2020

The requirements and characteristics of
Pasteurella novicida
transformations in liquid suspensions were studied. Transformation frequencies of 0.1 to 0.3% were routinely obtained when recipient cells were harvested from 16-hr agar plates and higher than 1% when logarithmic-phase broth-grown cells were used. Calcium ions were essential for transformations. The deoxyribonucleic acid dose response curve, kinetics of transformation, and
p
H optimum for transformations were similar to those of other bacterial transformation systems. The genetic relatedness of
P. novicida
and
P. tularensis
was established by transforming
P. novicida
mutants with deoxyribonucleic acid extracted from
P. tularensis
.
Sorbitol Metabolism in
Aerobacter aerogenes
Authors: Kelker N. E. , Anderson R. L.
Published: January 2020

Sorbitol (
d
-glucitol) metabolism in
Aerobacter aerogenes
PRL-R3 is shown to proceed via the pathway: sorbitol → sorbitol 6-phosphate →
d
-fructose 6-phosphate. Sorbitol phosphorylation is mediated by a phosphoenolpyruvate (PEP):sorbitol 6-phosphotransferase system, and sorbitol 6-phosphate oxidation by a pyridine-nucleotide-linked dehydrogenase. Mutants deficient in sorbitol 6-phosphate dehydrogenase or a component (enzyme I) of the phosphotransferase system did not grow on sorbitol, whereas revertants which had regained these enzymatic activities grew normally. Extracts of the enzyme I-deficient mutant failed to catalyze the phosphorylation of sorbitol in the presence of PEP, and adenosine 5′-triphosphate could not replace the PEP requirement for sorbitol phosphorylation in extracts of the wild-type strain.
Kinetics of Thermal Death of Bacteria
Authors: Moats William A.
Published: January 2020

Experimental observations on thermal injury and death of bacteria in the stationary phase can be explained by assuming that death results from inactivation of (
X
L
) of
N
critical sites. It is assumed: (i) that inactivation of individual sites occurs at random and follows first-order kinetics, (ii) that the critical sites are identical and of equal heat resistance, and (iii) the bacterial population is homogeneous in heat resistance. A method is described for calculating
k
(the rate constant for inactivation of individual sites),
N
(sites per cell), and
X
L
(the number which must be inactivated to cause death under the experimental conditions used) from experimental data. Theoretical curves calculated by using this model are identical with experimental curves, providing support for the assumptions used. Calculated values of
N
and
X
L
were 130 and 21.7 for
Pseudomonas viscosa
and 175 and 2.7 for
Salmonella anatum
. There is considerable uncertainty in the absolute values of
N
, but they are probably > 100. It is predicted that
X
L
will vary depending on the recovery medium used after heating. This theory is consistent with all experimental observations on thermal injury and death of bacteria.
Lipid Composition in the Classification of Nocardiae and Mycobacteria
Authors: Lechevalier Mary P. , Horan Ann C. , Lechevalier H.
Published: January 2020

Ninety-six strains of aerobic actinomycetes with a type IV cell wall (major amounts of meso-diaminopimelic acid, arabinose, and galactose) were analyzed for the presence of mycolic acids and nocardomycolic acids. The method used was comparatively simple and permits the separation of these organisms into two groups: the mycobacteria and the nocardiae. In general, strains received as mycobacteria contained mycolic acids, confirming the generic assignment made by other methods. On the basis of nocardomycolic acid content,
Mycobacterium brevicale, M. rhodochrous
, and
M. thamnopheos
should be placed in the genus
Nocardia
, and on the basis of mycolic acid content, strains recently isolated from bovine farcy should be placed in the genus
Mycobacterium. Nocardia farcinica
should be considered a
nomen dubium
and
N. asteroides
should be considered the type species of the genus.
Chemistry of Axial Filaments of
Treponema zuelzerae
Authors: Bharier M. A. , Rittenberg S. C.
Published: January 2020

Highly purified axial filaments have been prepared from the spirochete
Treponema zuelzerae
, which possess a fine structure similar to the “beaded” form of bacterial flagella. The preparations consist largely of protein but also contain small amounts of hexose (less than 1%). The buoyant density of these filaments is 1.29 g/cm
3
. At
p
H 4.3, in the presence of 4
m
urea and 10
−3
m
ethylenediaminetetraacetic acid, filament protein migrates as a single band in acrylamide gel electrophoresis. Filaments dissociate to subunits in acid, alkali, urea, guanidine or with heating, indicating that these subunits are not covalently bonded in the organized structure. This is consistent with amino acid analysis which reveals that, like bacterial flagella, the filaments are completely lacking in half-cystine. Sedimentation equilibrium measurements on dissociated axial filaments in 6
m
guanidine show that the subunits are homogeneous with respect to molecular weight. A weight-average molecular weight of 37,000 ± 1,600 daltons is obtained from these measurements. The amino acid composition of axial filaments is similar to that of various types of flagellin molecules, but the filament protein is somewhat richer in tyrosine, phenylalanine, and proline than flagellin. Tryptic peptide maps of axial filaments are consistent with the amino acid composition calculated for a molecular weight of 37,000 daltons. No amino terminal end group could be detected by the dansyl chloride method, suggesting that this end group might be blocked in the axial filament protein. The results obtained show that the axial filaments of
T. zuelzerae
are similar chemically to bacterial flagella and suggest that they are composed of aggregates of a single species of protein subunit.
Ultrastructural Characteristics ofCoccidioides immitis, a Morphological Variant ofCryptococcus neoformansandPodosypha ravenelii
Authors: Cutler Jim E. , Erke Keith H.
Published: January 2020

Electron microscopic examination ofCoccidioides immitisrevealed dense septum-associated bodies, characteristic ofAscomycetes. Similar examinations of a filamentous variant ofCryptococcus neoformansfailed to clarify the taxonomic position of this yeast but did not exclude the possibility that this organism is a heterobasidiomycete. Septal pores were not seen in either organism.
Selective Release of Proteins from
Spirillum itersonii
by Tris(hydroxymethyl)aminomethane and Ethylenediaminetetraacetate
Authors: Garrard W. T.
Published: January 2020

Treatment of
Spirillum itersonii
with tris(hydroxymethyl)aminomethane (Tris)-ethylenediaminetetraacetate (EDTA) results in the quantitative release of alkaline phosphatase and ribonuclease into the surrounding medium. At the same time, about 90% of the total cellular soluble cytochrome
c
is liberated. This process occurs within 1 min of treatment at both 24 and 4 C. Release of these proteins by Tris-EDTA treatment is highly selective, since only 9% of the total cell protein is liberated, concomitantly with less than 5% ribonucleic acid, deoxyribonucleic acid, and malate dehydrogenase. Different sigmoidal curves are obtained for release of proteins as a function of EDTA concentration. The order of liberation with increasing EDTA is as follows: alkaline phosphatase, protein, soluble cytochrome
c
, and ribonuclease. Treatment of cells with Tris-EDTA under conditions which cause extensive loss of alkaline phosphatase, soluble cytochrome
c
, and ribonuclease results in cell death, with cessation of protein and ribonucleic acid synthesis. Cells treated with EDTA in phosphate buffer (in the absence of Tris) liberate a large portion of their soluble cytochrome
c
, but negligible amounts of alkaline phosphatase and ribonuclease. Addition of Tris to cells pretreated with phosphate-buffered EDTA releases high levels of alkaline phosphatase, but not ribonuclease. These results suggest that a common surface alteration is not solely responsible for release of periplasmic proteins. More likely, each protein of the periplasm is bound in an independent and specific manner.
Recovery from
N
-Hydroxyurethan-Induced Death
Authors: Mullinix Kathleen P. , Rosenkranz Herbert S.
Published: January 2020

Bacteria (
Escherichia coli
) can recover from the lethal action of
N
-hydroxyurethan when they are incubated in drug-free liquid medium. This recovery, which is dependent upon energy metabolism, does not occur on solid medium. Recovery is accompanied by repair of the cellular deoxyribonucleic acid (DNA). A bacterial mutant deficient in DNA polymerase was extremely sensitive to the lethal action of hydroxyurethan. Data are presented which support the concept that DNA replication and DNA repair are mediated by different enzymes and that only the former process is inhibited by hydroxyurea.
Peptidoglycan Differences in Strains of
Bacillus cereus
Constitutive and Inducible for Penicillinase Production
Authors: Nickerson Kenneth W. , Day Richard A.
Published: January 2020

Strains of
Bacillus cereus
differing in penicillinase production were shown to possess cell walls of differing muramic acid contents.
Mechanism of Excretion of a Bacterial Proteinase: Demonstration of Two Proteolytic Enzymes Produced by a
Sarcina
Strain (Coccus P)
Authors: Sarner Nitza Z. , Bissell Mina J. , Di Girolamo Mario , Gorini Luigi
Published: January 2020

A
Sarcina
strain (Coccus P) produces two proteolytic enzymes. One is found only extracellularly, is far more prevalent, and is actively excreted during exponential growth. It is the enzyme responsible for the known strong proteolytic activity of the cultures of this strain. A second protease is, however, produced which remains associated with the intact cells but is released by the protoplasts. The two enzymes appear unrelated in their derivation. Calcium ions play an essential role in preventing autodigestion of the excreted enzyme.
Metabolism of Imidazole by a Pseudomonad
Authors: Oien Helen G. , Wright Lemuel D.
Published: January 2020

Intermediates formed during the microbial degradation of imidazole, namely 4(5)-imidazolone, formiminoglycine, and possibly glycine, are similar to those formed during metabolism of imidazole derivatives.
Deoxynucleoside Kinases of
Bacillus megaterium
KM
Authors: Wachsman J. T. , Morgan D. D.
Published: January 2020

Dialyzed extracts of
Bacillus megaterium
KM contain thymidine, deoxyadenosine, and deoxyguanosine kinase activities. Thymidine kinase activity is best with deoxyadenosine triphosphate or deoxyguanosine triphosphate (dGTP) as the phosphoryl donor, whereas the best deoxyadenosine kinase activity is obtained with dGTP or adenosine triphosphate. Deoxyguanosine kinase activity functions optimally with deoxycytidine triphosphate as the donor. Although the thymidine kinase activity of crude extracts does not have a demonstrable divalent cation requirement, the addition of Mg
2+
or Mn
2+
is necessary for the formation of thymidine di- and triphosphates. The synthesis of thymidine kinase appears to be partially derepressed by thymine starvation. Incubation of extracts with deoxyadenosine and dGTP results in the substantial accumulation of deoxyadenosine di- and triphosphates. Extracts deaminate deoxycytidine to deoxyuridine, presumably as a consequence of the action of deoxycytidine deaminase, and then convert deoxyuridine to deoxyuridylic acid.
B. megaterium
extracts do not contain any detectable deoxycytidine kinase activity.
Cell Wall and Peptidoglycan from
Lactobacillus fermenti
Authors: Wallinder Inga-Britt , Neujahr Halina Y.
Published: January 2020

Cell walls from
Lactobacillus fermenti
were prepared by differential centrifugation of disrupted cells, with and without trypsin treatment. Approximately 16% of the dry weight of walls was found in a crude trichloroacetic acid extract of the walls; half of this amount remained upon further purification. The purufied extract lacked alanine, but contained substantial amounts of glucosamine. The walls constituted 23 to 33% of the dry weight of the cell. The chemical composition of the various types of wall preparations and of the peptidoglycan from them was studied. The peptidoglycan contained equimolar proportions of glucosamine, muramic acid,
l
-alanine,
d
-glutamic acid, and lysine, with somewhat lower proportions of
d
-aspartic acid and
d
-alanine. The chemical composition of the peptidoglycan is similar to that reported for three other lactobacilli. In addition to the major constituents of walls and peptidoglycan, there were several minor amino acids. The protein and the amounts of the minor amino acids decreased, and among these threonine and arginine were completely absent from preparations obtained with trypsin. Such preparations contained higher proportions of the
d
-isomers of alanine, glutamic acid, and aspartic acid as compared to walls and peptidoglycan prepared without trypsin. In addition, walls isolated with the use of trypsin were susceptible to lysozyme, whereas those prepared without trypsin were not. However, the trypsin treatment did not result in any change of the ultrastructure as revealed by electron microscope studies.
Immunological Relationships Among Lactic Dehydrogenases in the GeneraLactobacillusandLeuconostoc
Authors: Gasser F. , Gasser Charlotte
Published: January 2020

Antisera were prepared against pure nicotinamide adenine dinucleotide-dependentd-lactic dehydrogenases ofLactobacillus leichmannii, L. jensenii, andL. fermenti. When tested against these three antisera, crude extracts of almost all species ofLactobacilluscontaining ad-lactic dehydrogenase give cross-reactions. Extensive pairwise comparisons between cross-reacting crude extracts by double diffusion experiments permit the recognition of groups of identical antigenic specificity among the lactic dehydrogenases of the various nomenspecies ofLactobacillus. The same groups are revealed by each of the three antisera. By analyses of spur formation, the groups of identical antigenic specificity can be arranged in order of decreasing similarity to the homologousd-lactic dehydrogenase used as the reference point. From the combined results obtained with the three antisera, a map of the antigenic relationships among thed-lactic dehydrogenases of lactobacilli can be constructed. Microcomplement fixation experiments with two of the three anti-d-lactic dehydrogenases antisera support the conclusions drawn from double diffusion experiments and provide a quantitative estimation of the antigenic relationships among the variousd-lactic dehydrogenases. An antiserum was also prepared against the purel-lactic dehydrogenase ofL. acidophilusgroup III. It cross-reacts with extracts of almost all lactobacilli containing anl-lactic dehydrogenase. With respect to species that contain bothd- andl-lactic dehydrogenases, this antiserum reveals the same groups of identical antigenic specificity as do the antisera directed againstd-lactic dehydrogenases. Other than the genusLactobacillus, only extracts ofLeuconostoccross-react with anti-d-lactic dehydrogenase. No extrageneric cross-reactions were obtained with the anti-l-lactic dehydrogenase.
Respiratory Chain of a Pathogenic Fungus,
Microsporum gypseum
: Effect of the Antifungal Agent Pyrrolnitrin
Authors: Wong David T. , Horng Jong-Sin , Gordee Robert S.
Published: January 2020

Pyrrolnitrin has been reported to inhibit
Bacillus megaterium
primarily by forming complexes with phospholipids and to block electron transfer of
Saccharomyces cerevisiae
between succinate or reduced nicotinamide adenine dinucleotide (NADH) and coenzyme Q. We found that pyrrolnitrin inhibited respiration of conidia of
Microsporum gypseum
. In mitochondrial preparations, pyrrolnitrin strongly inhibited respiration and the rotenone-sensitive NADH-cytochrome
c
reductase. The rotenone-insensitive NADH-cytochrome
c
reductase, the succinate-cytochrome
c
reductase, and the reduction of dichlorophenolindophenol by either NADH or succinate were inhibited to a lesser extent. However, the activity of cytochrome oxidase was not affected by pyrrolnitrin. The extent of reduction of flavoproteins by NADH and succinate, measured at 465 - 510 nm, was unaltered; however, the reduction of cytochrome
b
, measured at 560 - 575 nm, was partially inhibited by pyrrolnitrin. The level of totally reduced cytochrome
b
was restored with antimycin A. We, therefore, concluded that the primary site of action of this antifungal antibiotic is to block electron transfer between the flavoprotein of the NADH-dehydrogenase and cytochrome
b
segment of the respiratory chain of
M. gypseum
.
Involvement of Recombination Genes in Growth and Viability of
Escherichia coli
K-12
Authors: Capaldo-Kimball Florence , Barbour Stephen D.
Published: January 2020

We have studied the growth properties of 17 isogenic strains of
Escherichia coli
K-12 differing only in the
recA, recB, recC
, and
sbcA
alleles. We have observed the following. (i) All recombination deficient strains have decreased growth rates and decreased viabilities compared with recombination proficient strains. The large populations of nonviable cells in Rec
−
cultures may arise by spontaneous lethal sectoring (9). (ii) A
recA
mutant strain which is entirely recombination deficient and which shows high ultraviolet sensitivity and “reckless” deoxyribonucleic acid (DNA) breakdown has approximately the same growth rate and twice the viability as
recB
and
recC
mutant strains which have residual recombination proficiency, moderate ultraviolet sensitivity, and “cautious” DNA breakdown. (iii) Indirectly suppressed (
sbcA
−
) recombination proficient (Rec
+
) revertants of
recB
and
recC
mutant strains have approximately normal growth rates and are three times as viable as their Rec
−
ancestors (but not as viable as
rec
+
cells). We suggest the following hypothesis to account for the low viability of Rec
−
E. coli
. Single-strand breaks in the DNA duplex, necessary for normal bacterial growth, may be repaired in a Rec
+
cell. Failure of Rec
−
cells to repair this normal DNA damage may lead to the observed loss of viability.
Asymmetric Distribution of Guanine Plus Thymine Between Complementary Strands of Deoxyribonucleic Acid of Members of the
Enterobacteriaceae
Authors: Hershberger C. , Mickel S. , Rownd R.
Published: January 2020

Analysis of the deoxyribonucleic acid prepared from
Proteus mirabilis, Escherichia coli
, and
Serratia marcescens
in an alkaline CsCl gradient has shown that there is an asymmetric distribution of guanine plus thymine residues between the complementary strands of the deoxyribonucleic acid.
Physical Studies of the Drug-Resistance Transfer Factor in
Proteus
Authors: Haapala Daniel K. , Falkow Stanley
Published: January 2020

The transfer unit, RTF, derived from an R factor has been transferred to
Proteus mirabilis
and characterized physiochemically.
Metabolism of
d
-Arabinose: a New Pathway in
Escherichia coli
Authors: LeBlanc Donald J. , Mortlock Robert P.
Published: January 2020

Several growth characteristics of
Escherichia coli
K-12 suggest that growth on
l
-fucose results in the synthesis of all the enzymes necessary for growth on
d
-arabinose. Conversely, when a mutant of
E. coli
is grown on
d
-arabinose, all of the enzymes necessary for immediate growth on
l
-fucose are present. Three enzymes of the
l
-fucose pathway in
E. coli
,
l
-fucose isomerase,
l
-fuculokinase, and
l
-fuculose-l-phospháte aldolase possess activity on
d
-arabinose,
d
-ribulose, and
d
-ribulose-l-phosphate, respectively. The products of the aldolase, with
d
-ribulose-l-phosphate as substrate, are dihydroxyacetone phosphate and glycolaldehyde.
l
-Fucose, but not
d
-arabinose, is capable of inducing these activities in wild-type
E. coli
. In mutants capable of utilizing
d
-arabinose as sole source of carbon and energy, these activities are induced in the presence of
d
-arabinose and in the presence of
l
-fucose. Mutants unable to utilize
l
-fucose, selected from strains capable of growth on
d
-arabinose, are found to have lost the ability to grow on
d
-arabinose. Enzymatic analysis of cell-free extracts, prepared from cultures of these mutants, reveals that a deficiency in any of the
l
-fucose pathway enzymes results in the loss of ability to utilize
d
-arabinose. Thus, the pathway of
d
-arabinose catabolism in
E. coli
K-12 is believed to be:
d
-arabinose ⇌
d
-ribulose →
d
-ribulose-l-phosphate ⇌ dihydroxyacetone phosphate plus glycolaldehyde. Evidence is presented which suggests that the glycolaldehyde is further oxidized to glycolate.
New Regulatory Mutation Affecting Some of the Tryptophan Genes in
Pseudomonas putida
Authors: Maurer Richard , Crawford Irving P.
Published: January 2020

Three indole analogues, 5-methylindole, 5-fluoroindole, and 7-methylindole, and the tryptophan analogue 5-fluorotryptophan were found to inhibit the growth of wild-type
Pseudomonas putida
. Mutants resistant to these analogues were obtained. Some of the 5-fluoroindole- and 5-fluorotryptophan-resistant strains exhibit an abnormality in the regulation of certain
trp
genes. These strains excrete anthranilate when grown in minimal medium in the presence or absence of the inhibitor. In these strains, the
trpA, B
, and
D
gene products, the first, second, and fourth enzymes of the tryptophan pathway, are produced in 20-fold excess over the normal wild-type level. The other enzymes of the pathway are unaffected. Exogenous tryptophan is still able to repress the expression of the
trpABD
cluster somewhat. Similarity between the 5-fluoroindole- and 5-fluorotryptophan-resistant strains suggests that the former compound becomes effective through conversion to the latter. Repression and derepression experiments with two anthranilate-excreting, 5-fluoroindole-resistant strains showed coordinate variation of the affected enzymes. The locus conferring resistance and excretion is not linked by transduction to any of the
trp
genes.
Interaction Between the First Enzyme for Histidine Biosynthesis and Histidyl Transfer Ribonucleic Acid
Authors: Blasi Francesco , Barton Robert W. , Kovach John S. , Goldberger Robert F.
Published: January 2020

Previous studies suggested that phosphoribosyltransferase, which catalyzes the first step of the pathway for histidine biosynthesis in
Salmonella typhimurium
and which is sensitive to inhibition by histidine, plays a role in repression of the histidine operon. Recently, we showed that the enzyme has a high affinity for histidyl transfer ribonucleic acid (His-tRNA), which is known to participate in the repression process. In the present study, we have investigated further the interaction between the enzyme and His-tRNA. We found that His-tRNA binds at a site on phosphoribosyltransferase distinct from the catalytic site and the histidine-sensitive site; that the substrates of the enzyme inhibit the binding of His-tRNA, whereas histidine does not do so; that, once a complex has been formed between phosphoribosyltransferase and His-tRNA, the substrates of the enzyme decrease the stability of the complex, whereas histidine is without effect; and that purified phosphoribosyltransferase which has a defect in its inhibition by histidine (produced by mutation) displays an altered ability to bind His-tRNA, a finding which may be a reflection of the fact that mutants producing such a defective enzyme display an alteration of the repression process.
Impaired Transduction of R213 and Its Recovery by a Homologous Resident R Factor
Authors: Yoshikawa Masanosuke , Hirota Yukinori
Published: January 2020

Transduction by Plkc of drug-resistance markers of the factor R213 was shown to occur at an exceptionally low frequency (at less than 10
−8
of the input phage), and they could not be transduced by P22. When the recipient cells carried a homologous R factor derived from R213, markers were transduced by Plkc at a normal frequency (at about 10
−5
to 10
−6
of the input phage). Derivative R factors, transducible by Plkc at a normal frequency but being transferred by conjugation at a frequency lower than that of the original R213, were obtained. This type of transductant often segregated R
−
cells. In addition, several transductants contained R factors which were transferred normally by conjugation but were transduced by Plkc at as low a frequency as the original R213. This type of transductant was an effective recipient for transduction by Plkc of R213 when apparently “cured” by acridine treatment. No such effective “cured” recipients were obtained from the transductants with derivatives of R213 transducible at a normal frequency. Two possible interpretations are presented: (i) R213 produces a bacteriocin-like substance upon transduction, or (ii) the genome size of R213 is too large for all of its determinants to be transduced.
Beginning a Genetic Analysis of Conjugational Transfer Determined by the F Factor inEscherichia coliby Isolation and Characterization of Transfer-Deficient Mutants
Authors: Achtman Mark , Willetts Neil , Clark Alvin J.
Published: January 2020

Eighty-four transfer-deficient mutants of Flachave been isolated; 27 of these bear amber mutations and 1 mutant is temperature-sensitive. All the mutants transfer between 10−2and <10−5% as well as wild-type Flac, all are curable by acridine orange treatment, and all are resistant to the female-specific phage φII. Some of the mutants are partially sensitive to female-specific phage tau. Sixty-three of the mutants are resistant to the male-specific phages f1, f2, and Qβ; 15 are resistant only to f2; and 6 are sensitive to all three male-specific phages. Most of the mutants are still poor recipients in conjugation, but four of the mutants resistant to f1, f2, and Qβ have become good recipients. Those mutants resistant to all three male-specific phages do not seem to make F-pili.
Comment on the Use of Chloramphenicol to Study the Initiation of Deoxyribonucleic Acid Synthesis
Authors: Cooper Stephen , Weusthoff G.
Published: January 2020

Chloramphenicol cannot be used to distinguish different steps in the initiation of bacterial chromosome replication.
Isolation and Identification of Trehalase from
Pullularia pullulans
Authors: Merdinger Emanuel , Lange Charles F. , Booker Ben F.
Published: January 2020

Trehalase has been isolated from
Pullularia pullulans
. The enzyme, which is specific for trehalose, was purified approximately 800-fold. The optimal
p
H was found to be 4.0 and the Michaelis dissociation constant,
K
m
, was determined to be 3.2 × 10
−3
m
.
Starch Gel Electrophoresis of Fructose-6-Phosphate Phosphoketolase in the GenusBifidobacterium
Authors: Scardovi V. , Sgorbati B. , Zani G.
Published: January 2020

Three groups of nomenspecies of the genusBifidobacteriumwere distinguished by the different mobility of their fructose-6-phosphate phosphoketolase in starchgel electrophoresis; there is apparently a close relatedness between electrophoretic type of phosphoketolase and habitat.
Partial Purification and Properties of a Highly Specific Trehalose Phosphate Phosphatase from
Mycobacterium smegmatis
Authors: Matula Mike , Mitchell Mike , Elbein Alan D.
Published: January 2020

A specific trehalose phosphate phosphatase was purified approximately 50-fold from
Mycobacterium smegmatis
. The enzyme had a
p
H optimum of about 7.0 and was stimulated by Mg
2+
. The optimum concentration of Mg
2+
was about 1.5 × 10
−3
m
. Of other divalent cations tested, only Co
2+
showed some activity. The
K
m
for trehalose phosphate was found to be about 1.5 × 10
−3
m
. The enzyme showed slight activity toward mannose-6-P and fructose-6-P but was inactive on a large number of other phosphorylated compounds. Citrate was a competitive inhibitor of the enzyme both with respect to trehalose phosphate concentration and Mg
2+
concentration. This inhibition appears to be due to chelation of Mg
2+
by this compound. Ethylenediaminetetraacetic acid and NaF were also inhibitors of the enzyme, but these inhibitions were noncompetitive.
Growth Rate of
Escherichia coli
at Elevated Temperatures: Reversible Inhibition of Homoserine Trans-Succinylase
Authors: Ron Eliora Z. , Shani M.
Published: January 2020

The preceding paper (10) showed that the growth of
Escherichia coli
is slowed, without killing, at 40 to 45 C, and that in the several strains tested the cause is a decrease in the activity of homoserine trans-succinylase. These temperatures are now shown to inhibit the enzyme directly, in crude extracts and after partial purification. The effect is rapid and is immediately reversible, unlike the progressive and slowly reversible changes of conventional denaturation.
End-Product Regulation of the Tryptophan-Nicotinic Acid Pathway in
Neurospora crassa
Authors: Lester Gabriel
Published: January 2020

The regulation of the tryptophan-nicotinic acid pathway in
Neurospora crassa
was examined with mutants (
nic-2, nic-3
) which require nicotinamide for growth. The accumulation of
N
-acetylkynurenin and 3-hydroxyanthranilic acid by these mutants served to estimate the level of function of the early reactions in the pathway. In still cultures, maximal accumulation occurred with media containing growth-limiting amounts of nicotinamide; the accumulation of intermediates was almost negligible with nicotinamide in excess. Only nicotinamide and closely related compounds which also supported the growth of these mutants inhibited the accumulation of intermediates. The site of inhibition was assessed to be between tryptophan and kynurenin (or
N
-acetylkynurenin). The synthesis of
N
-acetylkynurenin was examined in washed germinated conidia suspended in buffer; the level of
N
-acetylkynurenin-synthesizing activity was inversely related to the concentration of nicotinamide in the germination medium. The addition of large amounts of nicotinamide to suspensions of germinated conidia did not affect their
N
-acetylkynurenin-synthesizing activity. Formamidase activity, kynurenin-acetylating activity, and gross tryptophan metabolism in germinated conidia was not influenced by the concentration of nicotinamide in the germination medium. The results obtained indicate that the site of inhibition by nicotinamide is the first step in the pathway, the tryptophan pyrrolase reaction. The data are interpreted as nicotinamide or a product thereof, such as nicotinamide adenine dinucleotide, acting as a repressor of the formation of tryptophan pyrrolase in
N. crassa
.
Porphyrin Overproduction by
Pseudomonas denitrificans:
Essentiality of Betaine and Stimulation by Ethionine
Authors: Demain Arnold L. , White Raymond F.
Published: January 2020

Ethionine supplementation of a defined medium for growth of
Pseudomonas denitrificans
inhibited vitamin B
12
overproduction and led to the elaboration of a red pigment. The pigment was shown to be coproporphyrin III. Inhibition by ethionine of cobalamin synthesis is probably due to interference of methylation of the corrin nucleus by methionine. Accumulation of coproporphyrin III is thought to result from interference by ethionine with the activity of methionine in the coproporphyrinogenase reaction; this would inhibit formation of heme, the feedback inhibitor and corepressor of δ-aminolevulinate synthetase, thus allowing unregulated synthesis of coproporphyrinogen III and its degradation product, coproporphyrin III. Betaine, known to be required for vitamin B12 overproduction, was found to be an essential requirement for porphyrin overproduction in the presence of ethionine. Low-level production of porphyrin, which occurs in the absence of ethionine, also required betaine supplementation. Betaine is thus required for overproduction of both corrins and porphyrins in
P. denitrificans
.
Dissimilation of Aromatic Compounds byAlcaligenes eutrophus
Authors: Johnson B. F. , Stanier R. Y.
Published: January 2020

The range of aromatic compounds that support the growth ofAlcaligenes eutrophushas been determined, and the pathways used for the dissimilation of these substrates have been explored, largely by enzymatic analyses. The β-ketoadipate pathway operates in the dissimilation of benzoate andp-hydroxybenzoate; the genetisate pathway, in the dissimilation ofm-hydroxybenzoate; and themetacleavage pathway, in the dissimilation of phenol andp-cresol.l-Tryptophan is oxidized via anthranilate; but the metabolic fate of anthranilate was not established. The metabolism of the three stereoisomers of muconic acid was also examined.
Temperature-Sensitive Recovery of a Mutant of
Escherichia coli
K-12 Irradiated with Ultraviolet Light
Authors: Shimazu Y. , Morimyo M. , Suzuki K.
Published: January 2020

URT-43 is a mutant of
Escherichia coli
K-12 which gives a much larger number of survivors when ultraviolet (UV)-irradiated bacteria are incubated on agar medium at 30 C than when they are incubated on the medium at 41 C, although in both cases the number of survivors is fewer than that given by its wild-type ancestor. The UV sensitivity of this mutant was found to be markedly influenced by the presence of a high concentration of NaCl or sucrose in the plating medium. Thus, when irradiated bacteria were plated on agar medium containing 2% NaCl or 0.5
m
sucrose at 30 C, they exhibited a resistance similar to that of their wild-type ancestor. At 30 C, there was also an extensive recovery in liquid M9 medium supplemented with all of the nutrients required for growth and NaCl or sucrose. At 41 C, however, the recovery was greatly inhibited. Direct chemical analysis of thymine dimers has revealed that no significant amount of the dimer was released from deoxyribonucleic acid during the period of extensive recovery. It was concluded, therefore, that the temperature-sensitive recovery of URT-43 does not accompany excision of the bulk of pyrimidine dimers. To learn the gene function involved in the recovery, double mutants carrying an additional mutation either in a
uvr
or a
rec
gene have been investigated for their UV sensitivities and recovery in liquid medium. It was found that
recA
−
and
recB
−
derivatives retain the ability of undergoing an efficient recovery at a low temperature, whereas
uvrB
−
and
uvrC
−
derivatives have completely lost this ability. For these reasons, it was concluded that the mechanism responsible for the recovery of URT-43 involves the function controlled by the
uvr
genes. The results of photoreactivation suggested that most of the entities dealt with during recovery were pyrimidine dimers.
Phenotypic Characterization and Deoxyribonucleic Acid Homologies ofPseudomonas solanacearum
Authors: Palleroni N. J. , Doudoroff M.
Published: January 2020

Twenty-six strains and colony variants ofPseudomonas solanacearumbelonging to four described biotypes were characterized, by using 169 phenotypic characters previously found useful in distinguishing among strains of otherPseudomonasspecies. Deoxyribonucleic acid (DNA) hybridization (intra- and interspecific DNA-DNA hybridizations) was performed by using the in vitro “DNA competition” technique.P. solanacearumappears to be a moderately homogeneous species, which is, at most, only remotely related to all other species of the genus studied to date. The four biotypes are not clearly distinct from one another with respect to nutritional characters or DNA homologies. Discrepancies between acid production and growth with some carbohydrates were noted. Difficulties were encountered in certain DNA competition experiments and some problems of the methodology are discussed.
Mode of Action of a Bacteriocin from
Serratia marcescens
Authors: Foulds John
Published: January 2020

The effects of bacteriocin JF246, produced by
Serratia marcescens
, on the incorporation of labeled leucine and thymidine, the synthesis of β-galactosidase, the active transport of labeled leucine and α-methyl-
d
-glucoside, and the cellular levels of adenosine triphosphate (ATP) in
Escherichia coli
were studied. This bacteriocin strongly inhibited the incorporation of leucine and thymidine into protein and deoxyribonucleic acid, respectively, as well as the active transport of leucine. The accumulation of α-methyl-
d
-glucoside, which is mediated by a phosphoenolpyruvate-dependent phosphotransferase system, was not markedly inhibited. The level of ATP in bacteriocin-treated cells rapidly fell to 10 to 15% of the control value. However, the kinetics of inhibition of macromolecular synthesis by various levels of bacteriocin was not related to the kinetics of ATP decline.
Transport-Limited Growth Rates in a Mutant of
Escherichia coli
Authors: Von Meyenburg Kaspar
Published: January 2020

Mutants of
Escherichia coli
B/r have been selected which require increased nutrient concentrations for half-maximal growth rate. This half-saturation constant (
K
m
) for growth on glucose is 10
−6
and 7 × 10
−4
m
for the wild type (CP 366) and the mutant (CP 367), respectively. Similarly, the
K
m
is increased for growth on many other carbohydrates (20- to 500-fold), for the anions PO
4
3−
and SO
4
2−
(ca. 100-fold), and for the uptake of several amino acids (20- to 50-fold). At sufficiently high concentrations of the nutrients, mutant and wild type grow equally fast. The yield in terms of cell mass per milligram of substrate is unaffected by the mutation. The phenotype of the parent is reestablished in what appears to be the reversion of a single mutation (
kmt
) which maps between
strA
and
metB
. The pleiotropic decrease of the affinities for transport of the various nutrients seems to be the result of a modification of the cell envelope which weakens the attachment of the various specific binding proteins to the periplasmic membrane. Since the mutant
K
m
values are increased considerably, high cell densities can be reached in batch cultures at growth-rate-limiting substrate concentrations (10
7
to 10
8
cells/ml). This allows chemical analysis of the cell composition; the application of the mutant to studies of bacterial physiology as function of growth rate is discussed.
Ribosome Patterns inEscherichia coliGrowing at Various Rates
Authors: Varricchio Frederick , Monier Roger
Published: January 2020

The distribution of ribosomes, 30 and 50Ssubunits and polysomes, at three different growth rates ofEscherichia colistrains B and K-12 has been studied. The usual percentage of subunits is about 20%. However, at the lowest growth rate (μ = generations/hour), μ = 0.45 at 30C, the proportion of subunits is about 30%. An exceptional situation exists in K-12 strains growing at maximum growth rate, μ = 1.35, where the percentage of subunits is 45%. Several points of control over ribosome production are thus indicated. It is suggested that “subunit pool” is essentially a reserve. Furthermore, the polysome content when related to deoxyribonucleic acid content varies directly with the growth rate, which indicates the average efficiency of polysomes in protein synthesis does not vary over the range of growth rates tested.
Characterization of a Thermolabile Sulfite Reductase from
Salmonella pullorum
Authors: Hoeksema Walter D. , Schoenhard Delbert E.
Published: January 2020

The biochemical basis for sulfite accumulation by sulfate-using revertants of
Salmonella pullorum
was determined. All of the sulfate-using mutants isolated from wild-type
S. pullorum
accumulated sulfite when grown at 37 but not at 25 C. The specific activity of reduced nicotinamide adenine dinucleotide (NADPH)-dependent sulfite reductase (H
2
S-NADP oxidoreductase, EC 1.8.1.2) and of reduced methyl viologen (MVH)-dependent sulfite reductase (H
2
S-MV oxidoreductase), in extracts prepared from cells incubated at 37 C, declined as the incubation period lengthened. However, the specific activity of both reductases from cells incubated at 25 C did not decline. Thermolability of cell-free NADPH-dependent sulfite reductase from cells of
S. pullorum
incubated at 37 C was greater than the lability of this enzyme either from cells of
S. typhimurium
incubated at 37 C or from cells of
S. pullorum
incubated at 25 C. Cells cultured at 37 C continued to accumulate sulfite when the incubation temperature was shifted to 25 C; cells cultured at 25 C and shifted to 37 C accumulated no sulfite, whereas these cells shifted to 41 C accumulated sulfite. It was concluded that the configuration of the sulfite reductase of
S. pullorum
strain 6–18 is a function of the incubation temperature at which synthesis occurs.