bluuebunny/crossref_metadata_2025 huggingface dataset:
Physiological and Serological Comparisons Among Strains ofMycoplasma granularumandMycoplasma laidlawii
Authors: Tully Joseph G. , Razin Shmuel
Published: January 2020

Mycoplasma granularumstrains grew on a medium devoid of animal serum or of serum fractions containing sterols; all strains possessed properties, including carotenoid biosynthesis, similar to those described forM. laidlawii. Some common antigenic components were noted amongM. granularumandM. laidlawiistrains by indirect fluorescent-antibody tests. The growth ofM. granularumstrains was slightly inhibited by antiserum toM. laidlawiiPG-8, and the electrophoretic patterns of cell proteins of theM. granularumstrains showed a close resemblance to that ofM. laidlawii. However, direct fluorescent-antibody procedures performed on colonies grown on a serum-free medium clearly distinguishedM. granularumfromM. laidlawii. The occurrence of nonsterol-requiring mycoplasmas, in addition toM. laidlawii, raises questions as to the taxonomy ofM. granularumand of the saprophytic mycoplasmas in general.
A Study of the
Moraxella
Group II. Oxidative-negative Species (Genus
Acinetobacter
)
Authors: Baumann P. , Doudoroff M. , Stanier R. Y.
Published: January 2020

A number of nutritional and biochemical properties of more than 100 strains of the oxidase-negative moraxellas (the
Mima-Herellea-Acinetobacter
group of bacteria) were studied. These properties included the range of carbon sources that can support growth, the utilization of nitrate, the production of proteolytic and lipolytic enzymes, and the reactions involved in the oxidation of sugars and of aromatic compounds. No evidence could be obtained for the accumulation of either poly-β-hydroxybutyrate or polysaccharide as intracellular reserve materials. Of 158 different compounds tested, the group as a whole could use 85 as sole carbon sources for growth. The nutritional spectra of the individual strains, however, differed widely, with a range of from 17 to 74 alternative substrates. On the basis of 56 selected nutritional and physiological characters used for a numerical analysis, the collection could be divided into two major groups of strains comprising at least seven less clearly defined clusters. Neither the hydrolysis of gelatin nor acid production from aldose sugars was found to be a reliable index of strain affinities indicated by the phenotypic analysis, although both properties were of some use in distinguishing between the subgroups. For reasons that are discussed, we propose that the oxidase-negative moraxellas be placed in the genus
Acinetobacter
Brisou and Prévot, for which a modified description is presented.
A. calco-aceticus
(Beijerinck) is proposed as the type species, of which
anitratum
is regarded as a synonym or variety. On the basis of the present studies and unpublished supporting evidence provided by M. Mandel on deoxyribonucleic acid (DNA) composition and by J. Johnson on DNA homologies, it is proposed that two other species in the genus,
A. lwoffi
(Audureau) and
A. hemolysans
(Henriksen), as well as one subspecies,
A. hemolysans haemolyticus
(Stenzel and Mannheim), be recognized provisionally.
Passive Cutaneous Anaphylaxis with Antigens from
Coxiella burneti
Authors: Peacock Marius , Munoz J. , Tallent George L. , Ormsbee Richard A.
Published: January 2020

Passive cutaneous anaphylaxis (PCA) was produced in guinea pigs sensitized with guinea pig
Coxiella burneti
phase I–II antiserum and challenged with dimethylsulfoxide- or trichloroacetic acid-soluble extracts from phase I cells. The PCA reaction could not be induced by whole or mechanically disrupted phase I or phase II
C. burneti
cells or by extracted cells or extracts of phase II cells. The antibody responsible for PCA was in the 7
S
γ
1
(fast γ) globulin. Sensitization of the skin by 7
S
γ
1
antibody could be blocked nonspecifically by 7
S
γ
1
globulin from normal serum or from phase II antiserum. The 7
S
γ
2
(slow γ) globulin antibody inhibited the reaction specifically. Some antiserum pools containing high agglutinin and complement-fixing titers to phase I
C. burneti
cells failed to initiate the PCA reaction, perhaps due to an imbalanced ratio of γ
1
to γ
2
specific globulins or to an imbalance in the ratio of specific to nonspecific γ
1
globulins. Agglutinins to phase I cells were found in both γ
1
and γ
2
antibody globulins. Complement-fixing antibodies were found in the γ
2
globulin fraction.
Alteration of Tryptophan-mediated Regulation in
Neurospora crassa
by Indoleglycerol Phosphate
Authors: Turner J. R. , Matchett W. H.
Published: January 2020

The accumulation of imidazoleglycerol phosphate during growth of
Neurospora crassa
in the presence of 3-amino-1,2,4-triazole was found to cause derepression of tryptophan synthetase and to inhibit the induction of kynureninase. Accumulation of indoleglycerol phosphate in response to growth in the presence of indole acrylic acid or anthranilic acid was also accompanied by derepressed synthesis of tryptophan synthetase. Enzyme synthesis in mutants (
his
-7 and
trp
-4) unable to form these intermediates was not altered under similar conditions. The rate of formation of tryptophan synthetase and kynureninase was found to differ in the presence of tryptophan and indole.
Biochemical Effects of Oxolinic Acid on
Proteus vulgaris
Authors: Pianotti Roland S. , Mohan Raam R. , Schwartz Benjamin S.
Published: January 2020

Oxolinic acid (1-ethyl-1,4-dihydro-6,7-methylenedioxy-4-oxo-3-quinolinecarboxylic acid) is an antimicrobial agent effective against a variety of gram-negative pathogens, including
Proteus
. With the exception of
Staphylococcus aureus
, oxolinic acid is inactive against gram-positive bacteria and against fungi. Our results suggest that oxolinic acid exerted its primary action on synthesis of deoxyribonucleic acid (DNA). The rate of thymidine-
2
-
14
C
incorporation into DNA was significantly depressed in the presence of 0.1 μg of oxolinic acid per ml and was markedly inhibited at 1 μg/ml. No evidence of complexing with DNA was observed. Pulse labeling with radioactive precursors revealed that at levels approximating the minimal inhibitory concentration, oxolinic acid had no effect on rate of incorporation of
14
C-valine into protein, uracil-
2
-
14
C
into ribonucleic acid, or sodium acetate-
1
-
14
C
into lipid. Filamentous forms of
P. vulgaris
ATCC 881 were observed after in vitro exposure to subinhibitory levels of oxolinic acid. Concentrations of oxolinic acid in excess of the minimal inhibitory concentration (0.39 μg/ml) did not cause lysis of cells of
P. vulgaris
or leakage of cytoplasmic materials. Mg
++
ions diminished the in vitro activity of oxolinic acid, possibly through formation of Mg
++
chelates
Differences in the Utilization of Glycerol and Glucose by
Mycobacterium phlei
Authors: Tepper Byron S.
Published: January 2020

A basic difference was found in the kinetics of uptake and utilization of glucose and glycerol by washed suspensions of
Mycobacterium phlei
. With glucose, the rates of uptake, respiration, and assimilation were saturated at low external substrate concentration. With glycerol, these rates were found to increase with increasing substrate concentration and did not show saturation at any concentration tested. Qualitatively similar patterns were observed for cells grown on either glycerol or glucose. Above a saturation concentration, ratios of cell
14
C to CO
2
14
C for uniformly labeled
14
C-glucose were constant at a value of 0.96. Glycerol-
U
-
14
C
, on the other hand, yielded cell-
14
C/CO
2
-
14
C ratios which were highest at the lowest glycerol concentration tested, and decreased with increasing substrate concentration. The distribution of the glucose and glycerol carbons assimilated into
M. phlei
were qualitatively similar. Quantitatively, however, the uptake and assimilation of glycerol was far more rapid than that of glucose for all substrate concentrations employed. These quantitative differences in the utilization of glycerol and glucose could account for the increased content of nonessential lipid and polysaccharide found in glycerol-grown
M. phlei
.
Nature of Unsaponifiable Lipids of a
Mycoplasma
Strain Grown with Isopentenyl Pyrophosphate as a Substitute for Sterol
Authors: Smith Paul F.
Published: January 2020

Mycoplasma
sp., strain J, which is unable to convert mevalonic acid to isopentenyl pyrophosphate (IPP) will grow with IPP as a substitute for sterol.
14
C-labeled IPP is incorporated into its unsaponifiable lipid. This unsaponifiable lipid was separated into three
14
C-labeled fractions, all of which possess spectral and chromatographic characteristics of polyterpenes.
Regulation of Nitrogen Fixation in
Azotobacter vinelandii
OP and in an Apparently Partially Constitutive Mutant
Authors: Sorger George J.
Published: January 2020

Methylamine and 2-methylalanine appeared to act as co-repressors of nitrogenase in
Azotobacter vinelandii
OP. They inhibited the growth of this organism on molecular nitrogen but not on nitrate, ammonia, or Casamino Acids; they prevented the formation of nitrogenase by cells transferred from repression to induction conditions; and they did not inhibit the activity of nitrogenase in vitro. A mutant of strain OP, selected on the basis of its relative resistance to methylalanine, appeared partially constitutive because nitrogenase in this strain was less sensitive to repressors than was the enzyme in the wild-type strain.
Methylenetetrahydrofolate Dehydrogenase of the Amethopterin-resistant Strain
Streptococcus faecium
var.
durans
A
k
and Its Repressibility by Serine
Authors: Albrecht Alberta M. , Pearce Franklin K. , Hutchison Dorris J.
Published: January 2020

The methylenetetrahydrofolate dehydrogenase of the amethopterin-resistant strain
Streptococcus faecium
var.
durans
A
k
was purified 100-fold. Because it is extremely labile, this enzyme required protection by 1 m
m
nicotinamide adenine dinucleotide phosphate (NADP
+
) during purification; 0.01 m
m
EADP
+
with 0.1% bovine plasma albumin stabilized the purified enzyme during storage at −20 C. Although the enzyme has properties of sulfhydryl enzymes, thiol compounds were not stabilizers. Oxidation of methylenetetrahydrofolate, catalyzed by the purified enzyme preparation, is NADP
+
-specific and yields methenyltetrahydrofolate and the reduced pyridine nucleotide.
K
m
values for NADP
+
and for 5,10-methylenetetrahydrofolate (prepared as the formaldehyde adduct of biologically synthesized
l
,
l
-tetrahydrofolate) were calculated to be 0.021 and 0.026 m
m
, respectively. Neither purine bases and their derivatives nor serine inhibited the reaction. In growing cultures, the differential rate of synthesis of the methylenetetrahydrofolate dehydrogenase was dependent upon the composition of the medium. A medium which contained acid-hydrolyzed casein, and thus an exogenous source of serine, was repressive for this enzyme. In a serine-free, completely defined medium, the amount of folate added (for serine synthesis de novo) affected the duration of the initial exponential growth phase. At the termination of this phase, which primarily reflected the onset of a decreased rate of serine biosynthesis, synthesis of the methylenetetrahydrofolate dehydrogenase was derepressed. Exogenous serine in the completely defined medium prevented the derepression. Furthermore, physiological concentrations of
l
-serine were repressive not only for the dehydrogenase but also for the methenyltetrahydrofolate cyclohydrolase and the serine hydroxymethyl-transferase. Concomitantly, the differential rate of synthesis of the formyltetrahydrofolate synthetase of
S. faecium
var.
durans
A
k
was increased. Apparently, serine regulates the differential rates of syntheses of these enzymes.
Nature of the Carrier State of Bacteriophage SP-10 inBacillus subtilis
Authors: Kawakami Masaya , Landman Otto E.
Published: January 2020

Although the association of phage SP-10 withBacillus subtilisW-23-Srpersists in heat- and antiserum-resistant form through the spore stage, it is unstable in vegetative cells and frequently terminates in loss of the carried phage or in lysis. On low-tonicity media, the plating efficiency of carrier cells is low. However, high concentrations of succinate or sucrose or a slowed growth rate preserve viability: on 0.48msuccinate-agar, the viable count per optical density unit is the same as that of a noncarrier control culture. Carrier clones retain phage on 0.48msuccinate-agar. At higher succinate levels, many colonies emerge free of phage; at 1msuccinate, all are cured, probably because high succinate inhibits reinfection. Growth of carrier cells in liquid medium with antiphage serum results in rapid curing; events in such cultures with and without succinate were studied quantitatively by tracing the emergence of sensitive cells, the multiplication and induction of carrier cells, and the sensitivity of carrier cells to superinfection with virulent phage. During log phase, 40 to 70% of the carrier cells became sensitive to virulent phage, although the same cells were insensitive during lag and stationary phase. Apparently, fluctuations in repressor levels are responsible. Spontaneous induction of carrier cells followed a qualitatively similar pattern, perhaps in response to changes in level of the same repressor. Production of sensitive segregants by carrier followed a different course, presumably because the repressor does not affect segregation. Many sensitive cells were found two to three divisions after inoculation in antiserum medium. This suggests that each inoculum cell contained one or only a few phage replicons. The data are compatible with the idea that the carrier state in media without antisera is maintained entirely by reinfection and without replication of phage in the latent state. Alternative models which involve replication of latent phage are not ruled out, however.
Recombination-deficient Mutant of
Salmonella typhimurium
Authors: Wing Jennifer P. , Levine Myron , Smith Hamilton O.
Published: January 2020

A recombination-deficient (Rec
−
) ultraviolet-sensitive mutant of
Salmonella typhimurium
was isolated. The mutant grows more slowly than the wild-type strain and degrades its deoxyribonucleic acid extensively both during normal growth and after ultraviolet irradiation. Evidence is presented that a growing Rec
−
population consists of two types of cells, one which can divide and one which cannot.
Requirements for Macromolecular Synthesis in the Establishment of β-Galactosidase Repression in Zygotes
Authors: Caster John H. , Melechen Norman E.
Published: January 2020

Inhibitors of protein synthesis do not consistently prevent formation of the
lac
operon repressor, according to several published reports, although direct evidence indicates that the repressor is a protein. Inhibition of ribonucleic acid (RNA) synthesis has never been shown to block lactose repression. These results have raised the possibility that repressor is synthesized in some unusual fashion. We have studied the effect of various inhibitors upon the establishment of repression in zygotes, utilizing conditions which minimize catabolite repression. Inhibition of protein synthesis by either chloramphenicol treatment or tryptophan deprivation blocked repressor formation in our experiments. Sodium borate and 6-azauracil are compounds reported to be specific inhibitors of RNA synthesis, and their behavior in control experiments is consistent with this specificity. Both delayed the establishment of repression. Thymine deprivation, either by starvation of a thymine auxotroph or by treatment with 5-fluorodeoxyuridine, did not delay the onset of repression. We conclude that repressor formation requires RNA synthesis and probably utilizes the usual protein-forming mechanisms.
Fine Structure of Selected Marine Pseudomonads and Achromobacters
Authors: Wiebe William J. , Chapman George B.
Published: January 2020

The fine structure of more than 20 marine pseudomonads and more than 15 achromobacters was examined. Under the conditions extant, clear differences between members of these two groups were seen. The pseudomonads displayed the characteristic gram-negative morphology: the cell wall was irregularly undulant and the cytoplasmic membrane more nearly planar, ribonucleoprotein (RNP) particles were loosely packed throughout the periphery of the cytoplasm, and the deoxyribonucleic acid (DNA) was axially disposed. Cell division appeared to be by constriction. Some strains characteristically produced evaginations or blebs of the cell wall. Occasionally, thick, densely stained ring structures were seen which are possibly analogous to mesosomes. In contrast, the achromobacters demonstrated a regularly undulant outer cell wall element and a planar inner wall. The cytoplasmic membrane was thin and not readily observed. RNP particles were densely stained and tightly packed in the cytoplasm; the DNA was most often lobate in disposition. Cellular division was mediated by the formation of a septum which consisted of the cytoplasmic membrane and the inner element of the cell wall. Mesosomes were observed in all of the strains examined. Dense inclusion bodies were also seen in many strains.
Ectothiorhodospira mobilis
Pelsh, a Photosynthetic Sulfur Bacterium Depositing Sulfur Outside the Cells
Authors: Trüper Hans G.
Published: January 2020

From salt flats on the Galapagos Islands, two strains of a red photosynthetic bacterium were isolated and identified as
Ectothiorhodospira mobilis
, an organism first described by Pelsh in 1937. The cells are curved in a short spiral, 0.7 to 1.0 μ wide and 2.0 to 4.8 μ long. They are motile by a polar tuft of flagella. Cells contain several large stacks of lamellar membranes, carrying the pigments bacteriochlorophyll
a
and carotenoids of the spirillo xanthin series. Cell division occurs by binary fission, not budding. The organism is strictly anaerobic and obligately photosynthetic. Its ability to grow well with sulfide, sulfur, thiosulfate, or sulfite as photosynthetic H donors puts it taxonomically in the
Thiorhodaceae
. During growth with sulfide, elementary sulfur is deposited outside the cells in the medium and disappears during further growth. A limited number of organic carbon compounds can be utilized as hydrogen donors in place of inorganic sulfur compounds. Under these conditions, sulfate can serve as the sulfur source. The enzymes catalase and hydrogenase are present. The newly isolated strains require vitamin B
12
. They also require a salinity of 2 to 3% NaCl, but they are not extreme halophiles. The organism is not identical with any of the species listed in
Bergey's Manual
.
Correlation Between Spore Structure and Spore Properties in
Bacillus megaterium
Authors: Rode L. J.
Published: January 2020

The spores of six strains of
Bacillus megaterium
were divided into two distinct groups on the basis of germination. Three of the strains germinated in a mixture of
l
-alanine and inosine (AL type spores), and three strains germinated in a mixture of glucose and potassium nitrate (GN type spores); recriprocal germination in the respective solutions did not occur. The AL spores and the GN spores were morphologically distinct. Other differences between the two spore groups included germination inhibition characteristics, dipicolinic acid content, hexosamine content, phosphorus and magnesium content, spore coat features, ion exchange properties, and heat resistance. A correlation appears to exist between spore morphology and certain other spore properties in strains of
B. megaterium
.
Immunogenicity of Cell Walls from Various Mycobacteria Against Airborne Tuberculosis in Mice
Authors: Brehmer Werner , Anacker Robert L. , Ribi Edgar
Published: January 2020

Protective potency of oil-treated cell walls of various mycobacteria against airborne infection of mice with a few cells of
Mycobacterium tuberculosis
H37Rv was compared with that of viable BCG. Although less potent than BCG cell walls, the cell walls of atypical mycobacteria of Runyon's groups I to IV protected against challenge by aerosol to some degree. Protection afforded by cell walls of H37Rv and of the avirulent mutants H37Ra and Washington II was comparable to that provided by BCG cell walls. However, cell walls of a highly virulent strain of
M. bovis
(Bovinus I) provided the best protection yet achieved. Present evidence suggests that protective substances are shared by all mycobacteria but in differing amounts; the relationship between virulence and immunogenicity has yet to be clarified.
Microbial Assimilation of Hydrocarbons I. Fatty Acids Derived from Normal Alkanes
Authors: Makula R. , Finnerty W. R.
Published: January 2020

Fatty acids derived from
Micrococcus cerificans
growing at the expense of odd- and even-carbon normal alkanes were studied. Results demonstrated that cultures grown with a variety of nonhydrocarbon substrates serving as sole carbon and energy source yielded only even-carbon fatty acids. Even-chain alkanes, dodecane through octadecane serving as sole carbon source, resulted in even-carbon fatty acids with direct correlation between carbon number of the major fatty acid species and carbon number of the alkane substrate. Odd-carbon alkanes, undecane through heptadecane serving as sole carbon source, yielded both odd- and even-carbon fatty acids. A transitional shift from even-carbon fatty acids to odd-carbon fatty acids was observed as the carbon number of the alkane substrate increased. Unsaturated fatty acids were found to comprise a significant percentage of all profiles. Analysis of unsaturated fatty acids showed all odd- and even-carbon acids analyzed were Δ
9
monounsaturated fatty acids.
New Procedures for Purification of
l
-Asparaginase with High Yield from
Escherichia coli
Authors: Roberts Joseph , Burson Gene , Hill Joseph M.
Published: January 2020

l
-Asparaginase is now known to be a potent antineoplastic agent in animals and has given complete remission in some human leukemias. Extensive clinical trials of this enzyme, however, were not possible in the past because of inadequate production of this substance. We have developed practical procedures for producing
l
-asparaginase in yields of sufficient quantity and purity for more extensive clinical evaluation. The nutritional requirements for optimal production of biologically active
l
-asparaginase by a strain of
Escherichia coli
have been ascertained. The highest yields of enzyme were obtained when cells were grown aerobically in a corn steep medium. Good enzyme production was associated with media containing
l
-glutamic acid,
l
-methionine, and lactic acid. The addition of glucose to the medium, however, resulted in depressed production of
l
-asparaginase. Sodium ion appeared to suppress
l
-asparaginase production. With the procedure described for isolation of biologically active
l
-asparaginase from
E. coli
, stable
l
-asparaginase preparations with a specific activity of 620 IU per mg of protein (1,240-fold purification with 40% total recovery) were obtained.
Myeloperoxidase-Halide-Hydrogen Peroxide Antibacterial System
Authors: Klebanoff Seymour J.
Published: January 2020

An antibacterial effect of myeloperoxidase, a halide, such as iodide, bromide, or chloride ion, and H
2
O
2
on
Escherichia coli
or
Lactobacillus acidophilus
is described. When
L. acidophilus
was employed, the addition of H
2
O
2
was not required; however, the protective effect of catalase suggested that, in this instance, H
2
O
2
was generated by the organisms. The antibacterial effect was largely prevented by preheating the myeloperoxidase at 80 C or greater for 10 min or by the addition of a number of inhibitors; it was most active at the most acid
p
H employed (5.0). Lactoperoxidase was considerably less effective than was myeloperoxidase when chloride was the halide employed. Myeloperoxidase, at high concentrations, exerted an antibacterial effect on
L. acidophilus
in the absence of added halide, which also was temperature- and catalase-sensitive. Peroxidase was extracted from intact guinea pig leukocytes by weak acid, and the extract with peroxidase activity had antibacterial properties which were similar, in many respects, to those of the purified preparation of myeloperoxidase. Under appropriate conditions, the antibacterial effect was increased by halides and by H
2
O
2
and was decreased by catalase, as well as by cyanide, azide, Tapazole, and thiosulfate. This suggests that, under the conditions employed, the antibacterial properties of a weak acid extract of guinea pig leukocytes is due, in part, to its peroxidase content, particularly if a halide is present in the reaction mixture. A heat-stable antibacterial agent or agents also appear to be present in the extract.
Respiratory Pigments of
Crithidia fasciculata
Authors: Hill George C. , White David C.
Published: January 2020

Mitochondria were isolated from the heme-requiring insect trypanosomatid,
Crithidia fasciculata
, which had respiratory activity, showed a P/O ratio with succinate of 0.5 to 1.0, and contained 40 to 50% of the heme
a
and heme
c
found in the intact cells. Cytochromes
b, c
555
, possibly
c
1
, cytochrome oxidase, a carbon monoxide-binding pigment, and flavoproteins were detectable in the spectra of both intact cells and mitochondria. Cytochrome
c
555
is a basic protein that was extracted from cells and mitochondria with salt solutions. The molar ratio of heme
c
to heme
a
was approximately 2:1 in both cells and mitochondria. This organism could possibly serve as a model for studies of the respiratory activity of the pathogenic trypanosomes.
Inhibition of
Histoplasma capsulatum
by
Candida albicans
and Other Yeasts on Sabouraud's Agar Media
Authors: Kapica L. , Shaw C. E. , Bartlett G. W.
Published: January 2020

The inhibition of growth of
Histoplasma capsulatum
by
Candida albicans
and other yeasts on Sabouraud's agar was investigated.
Histoplasma
(yeast-phase inoculum) was grown alone and in mixtures with yeasts at 25 C for 4-week periods. As few as 10 colonies of
C. albicans
completely inhibited the growth of approximately 50,000 potential colonies of
Histoplasma
. The
p
H was determined in cultures of 36 colonies of
Candida
on media containing 1, 2, and 4% glucose by spotting the agar with
p
H indicators. A drop in the
p
H became noticeable in all three media about the 3rd day of incubation, and a
p
H of 3.5 was reached in about 7 days. Subsequently, the
p
H remained almost stationary in the 4% glucose-agar, rose slowly in the 2% glucose-agar, and rose sharply in the 1% glucose-agar. The growth of
Histoplasma
was inhibited completely at
p
H 4 and below. When the
p
H was controlled in mixed cultures, some growth of
Histoplasma
was obtained. Substitution of maltose for glucose delayed the development of acidity and allowed the appearance of numerous mycelial colonies in the presence of
Candida
. This growth was arrested as soon as the medium became acid. Four other species which also acidified the Sabouraud's medium effected similar inhibition. It was thus shown that severe and prolonged acidity produced by some yeasts in the sugar-rich Sabouraud's media is alone sufficient to completely inhibit
Histoplasma
during the standard 4-week incubation of specimens such as sputum.
Peptidoglycan of
Myxococcus xanthus
: Structure and Relation to Morphogenesis
Authors: White David , Dworkin Martin , Tipper Donald J.
Published: January 2020

The chemical nature and distribution of the peptidoglycan in
Myxococcus xanthus
at various stages of the cellular life cycle were investigated. Vegetative cells and microcysts contained approximately 0.6% by weight of peptidoglycan. The overall composition of the peptidoglycan was similar in both cell types and was approximately 1 glutamic acid, 1 diaminopimelic acid, 1.7 alanine, 0.75
N
-acetylglucosamine, and 0.75
N
-acetylmuramic acid. (We have assumed that all the hexosamines are
N
-acetylated.) The sizes of the subunits (estimated by gel filtration) solubilized by muramidases were considerably larger (tetramer and oligomer) in the microcysts than in the vegetative cells (mostly dimer). There was a transient decrease in cross-linking (measured as an increase in the amount of free amino group of diaminopimelic acid) during the stage of microcyst formation when the cells converted from ovoids to spheres. At the same time, there occurred a large and rapid increase in a galactosamine derivative which may have reflected the synthesis of capsular material. Immediately prior to this period of morphogenesis, the cells became resistant to penicillin but remained sensitive to
d
-cycloserine. The walls of vegetative cells were completely disaggregated by trypsin and sodium lauryl sulfate, suggesting a discontinuous peptidoglycan layer. This was no longer apparent after the ovoid-sphere stage of microcyst formation. The relationship to morphogenesis of the chemical changes in the cell wall is discussed.
Fatty Acids in the GenusBacillusII. Similarity in the Fatty Acid Compositions ofBacillus thuringiensis, Bacillus anthracis, andBacillus cereus
Authors: Kaneda Toshi
Published: January 2020

The nature and relative abundance of fatty acids produced by two strains each ofBacillus thuringiensisand ofB. anthraciswere studied by gas-liquid chromatography on a 12,000 theoretical plate polyester column capable of partially resolving iso- and anteiso-fatty acids with the same number of carbon atoms. Unsaturated fatty acids as the bromo derivatives were separated from the saturated acids and resolved in a short SE-30 column by use of programmed-temperature gas chromatography. All four strains produced 16 major fatty acids: 9 branched (i-C12, i-C13, i-C14, i-C15, i-C16, i-C17, a-C13, a-C15, and a-C17), 3 normal (n-C14, n-C15, and n-C16), and 4 monounsaturated (i-C161=, i-C171=, a-C171=, and n-C161=), in addition to some minor fatty acids. In all cases, 12 branched acids, including saturated and monounsaturated, made up over 70% of the total fatty acids, and iso-C15acid was most abundant. These fatty acid distribution patterns were very similar to those ofB. cereusandB. cereusvar.mycoides. There were, however, minor but clear differences between the fatty acid distribution patterns ofB. thuringiensisandB. anthracis. B. thuringiensis, likeB. cereus, produced higher proportions of i-C13, a-C13, and i-C14fatty acids than didB. anthracis. This difference between these two species could be useful as a supplemental criterion in their differentiation. Indications are that the enzyme systems for monounsaturated fatty acid synthesis inB. thuringiensisandB. anthracisprefer normal fatty acids as substrates rather than branched-chain fatty acids.
Biosynthesis of the O Antigen from
Citrobacter
139
Authors: Yuan R. , Horecker B. L.
Published: January 2020

The biosynthesis of the O antigen of
Citrobacter
139 (
Escherichia coli
3 Zurich 4,5,12:z
20
) was shown to proceed through a series of lipid-linked intermediates, similar to those involved in O-antigen synthesis in
Salmonella
. Galactose was the first sugar incorporated, followed by rhamnose and mannose. Abequose was incorporated from cytidine diphosphate (CDP)-abequose only when all three of the other nucleotide sugars (uridine diphosphate galactose, guanosine diphosphate mannose, and thymidine diphosphate rhamnose) were present. Rhamnosyl-galactosyl 1-phosphate and mannosyl-rhamnosyl-galactosyl 1-phosphate were identified as the products of mild alkaline hydrolysis of the lipid-linked intermediates.
Chromosomes in
Bacillus subtilis
Spores and Their Segregation During Germination
Authors: Yoshikawa Hiroshi
Published: January 2020

Spores of a thymine-requiring mutant of
Bacillus subtilis
168 leucine
–
, indole
–
, thymine
–
) were uniformly labeled with
3
H-thymidine. These were seeded on thinlayer agar plates where they germinated into long-chained microcolonies. Autoradiograms were used to measure the distribution of labeled deoxyribonucleic acid in the chains of cells, which ranged in length from 2 to 32 cells. Four major grain clusters appeared in most chains. These clusters were homogeneous in size; their grain numbers were distributed symmetrically from 9 to 15 with an average of 12.0. When three or fewer major clusters appeared in short chains, some of them were composed of two subclusters. However, there were always four clusters per chain when these subclusters were counted as individuals. Groupings containing two to eight grains appeared, as well as the four major clusters in longer chains. These minor groups were fragments of the major clusters. In contrast to the symmetrical distribution of major clusters, fragmented clusters were distributed at random, indicating random fragmentation. The total number of major and minor clusters increased at a constant exponential rate when measured against total cell number per chain, i.e., number of generations. It was calculated from the rate that a detectable fragmentation, at least 16% of a conserved unit (defined as a single strand of the complete chromosome), occurred every 6.0 generations. These results led us to conclude that each
B. subtilis
spore contained four conserved units or two completed chromosomes. Segregation of the four units into progeny cells was almost random. The one notable exception was a conserved unit which frequently appeared in a terminal cell to which an empty spore coat was attached. The presence of two chromosomes in the spore is consistent with our proposed structure of the completed chromosome, in which two sister chromosomes are covalently linked at the initiation region. This double chromosome may be incorporated into the spore without further structural change.
Vitamin K Deficiency in
Fusiformis nigrescens
I. Influence on Whole Cells and Cell Envelope Characteristics
Authors: Lev Meir
Published: January 2020

Vitamin K depletion in the vitamin K-requiring anaerobe
Fusiformis nigrescens
resulted in the formation of elongated cells. In the presence of vitamin K, inhibition by cyanide and heme depletion did not affect cell morphology. Peptide depletion, as well as inhibition by chloramphenicol, ethionine, or fluorophenylalanine, also resulted in formation of elongated cells. Chemical analysis of cells and envelopes showed that protein, lipid, and deoxyribonucleic acid levels were similar in vitamin-supplemented and depleted cells; however, ribonucleic acid (RNA) levels in depleted cells and envelopes were significantly higher than in K-supplemented cells. Sections of cells of both groups showed minor differences in cell surfaces. The relationship between altered cell envelopes and increased RNA levels in K-deficient bacteria indicated a membrane-mediated effect of vitamin K on RNA and possibly protein synthesis in this microorganism.
In Vitro Production of Choleragen and Vascular Permeability Factor byVibrio cholerae
Authors: Evans Doyle J. , Richardson Stephen H.
Published: January 2020

The in vitro production of significant amounts of extracellular choleragen and vascular permeability factor (PF) byVibrio choleraestrain VC-12 (Ogawa) in a basal peptone medium required forced aeration, low incubation temperature, and a low initialpH. Filtrates of alkaline peptone cultures of VC-12 grown at 37 C contained an ion translocase inhibitory activity but neither choleragen nor PF activity, Sterile filtrates ofpH 6.5 peptone cultures of VC-12 grown at 29 C contained no ion translocase inhibitory activity but possessed choleragen activity (lethality for the suckling rabbit) and PF activity to the extent that the intradermal inoculation of 0.1 ml of a 1:12,288 dilution of such a filtrate gave rise to a vascular permeability reaction (8 by 8 mm in diameter) in the guinea pig. PF excretion occurred during the late logarithmic phase of growth but did not appear to be the consequence of cell lysis. The PF activities of strains VC-12 and 569B (Inaba) were neutralized to the same extent by anticholeragen antiserum prepared against crude 569B choleragen.
Leukocyte Lactate Dehydrogenase Changes as an Indicator of Infection Prior to Overt Symptoms
Authors: Leise Esther M. , Gray Irving , Ward Martha K.
Published: January 2020

Lactic acid dehydrogenase (LDH) concentration of rabbit serum and leukocytes was followed during the course of an acute infection with
Diplococcus pneumoniae
. Control values were obtained prior to infection, and again 4, 24, and 48 hr later. LDH isozymes were characterized by acrylamide gel electrophoresis and quantitated by densitometry. An increase in serum LDH was observed as early as 4 hr after infection. These levels returned to normal in 24 hr and rose again 48 hr after infection. The LDH level of leukocytes, from 10 of 12 infected rabbits, rose rapidly during the 24-hr period after exposure. The levels were two to three times the original preinoculation level for that animal. In six of these rabbits, this LDH elevation occurred 4 hr after inoculation and preceded the onset of fever. Change in the type of leukocyte did not account for the increase in cellular LDH. All infected rabbits showed approximately the same increase in polymorphonuclear leukocytes, but not all developed comparable increases in LDH. The isozyme patterns obtained, when defined amounts of enzyme were applied to the gel for electrophoresis, were characterized for the most part by a three-enzyme pattern. Increasing amounts of enzyme occasionally revealed a fourth, more cathodal, enzyme. The more cathodic enzymes appear to be the most responsive when sudden shifts in enzyme concentration occur within the cell.
Mannose-containing Polysaccharides of the Apiculate Yeasts
Nadsonia, Hanseniaspora, Kloeckera
, and
Saccharomycodes
, and Their Use as an Aid in Classification
Authors: Spencer J. F. T. , Gorin P. A. J.
Published: January 2020

The mannose-containing polysaccharides formed by species of
Nadsonia, Hanseniaspora, Kloeckera
, and
Saccharomycodes
were extracted with hot aqueous alkali and purified by precipitation as their copper complexes.
N. fulvescens
and
N. elongata
formed galactomannans, while
Hanseniaspora
and
Kloeckera
species and
S. ludwigii
formed mannans.
H. valbyensis, H. uvarum
, and
K. apiculata
were a group which formed mannans which had identical H-1 regions in their proton magnetic resonance (PMR) spectra, and
H. osmophila, K. africana
, and
K. magna
mannas formed another group based on similar spectra.
K. javanica
formed a mannan with an H-1 spectral region which resembled that of the
H. valbyensis
group in some respects and that of the
H. osmophila
group in others. The H-1 portion of the PMR spectrum of
S. lugwigii
mannan was very complex and was unlike that of any other apiculate yeast studied.
Mechanism of Caffeine Enhancement of Mutations Induced by Sublethal Ultraviolet Dosages
Authors: Sideropoulos Aris S. , Shankel Delbert M.
Published: January 2020

Certain chemical compounds increase mutation frequency of
Escherichia coli
B/r significantly when used in conjunction with nonlethal ultraviolet (UV) dosages. Studies were done to elucidate the mechanism of this enhancing mutational effect. Dark survival curves showed that 500 μg of caffeine per ml in the postirradiation medium markedly decreased survival to 60 ergs/mm
2
of UV in strain B/r. Caffeine did not markedly decrease survival to UV in strain B/r WP-2
hcr
−
. At least 90% of the mutations induced to streptomycin resistance by UV and 85% of those induced by UV with caffeine could be photoreversed. Experiments with thymine analogues suggested that thymine dimerization at the streptomycin locus was the primary premutational photoproduct induced by sublethal UV dosages. Caffeine did not interfere with the photoreversal of induced mutants, indicating that it probably does not bind to the photoreactivating enzyme or to a UV-induced lesion in the DNA. Addition of DNA or irradiated DNA with 500 μg of caffeine per ml resulted in no loss of the caffeine activity. The excision of UV-induced thymine-containing dimers from
E. coli
B/r T
−
was investigated in the presence and absence of caffeine. Our results indicated that caffeine prevents excision of thymine dimers, presumably by binding to the excising enzyme. This binding results in an impairment of repair, which produces the increase in mutant numbers.
Serum-mediated Immune Cellular Responses to
Brucella melitensis
I. Role of a Macrophate-stimulating Factor in Promoting Ingestion of
Brucella
by Streptomycin-protected Cells
Authors: Ralston Doris J. , Elberg Sanford S.
Published: January 2020

Injection of rabbits with living
Brucella melitensis
Rev I induced the appearance of a macrophage-stimulating-factor (MSF) in the sera of these animals. MSF was involved in ingestion of bacilli, hastening the formation of protected loci as measured by the addition of lethal amounts of dihydrostreptomycin. When sufficient time had been allowed for effective ingestion, streptomycin had little effect. This in turn allowed for multiplication of bacilli intracellularly in the presence of 5 to 250 μg of drug per ml. MSF mediated more effective ingestion by both immune and normal macrophages. Under such conditions, there was little, if any, intracellular growth restriction by macrophages from immune animals. The activity appeared within the first 5 days after injection with 10
9
organisms and was present for several months. Three weeks after injection, the activity of serum was partially heat-labile. All activity was removed by absorption with heat-killed or living Rev I cells, suggesting that a specific globulin is concerned.
Isolation of
Acinetobacter
from Soil and Water
Authors: Baumann Paul
Published: January 2020

An enrichment culture procedure for isolating members of the genus
Acinetobacter
from soil and water is described. It involves the use of vigorously aerated mineral media at relative low
p
H, supplemented with acetate or other suitable carbon source and nitrate as nitrogen source. With this method, virtually all samples of soil and water yielded representatives of this genus. Semiquantitative comparisons of the numbers of
Acinetobacter
and of all bacteria capable of aerobic growth in a complex medium revealed that
Acinetobacter
constituted no less than 0.001% of the total heterotrophic aerobic population in soil and water and was one of the predominant organisms in some water samples.
Effect of Mutation to Streptomycin Resistance on Amber Suppressor Genes
Authors: Otsuji Nozomu , Aono Hiroyuki
Published: January 2020

Three classes of nonidentical streptomycin-resistant mutations were distinguished in
Escherichia coli
by their effect on the efficiency of suppression by an amber suppressor gene,
sup E
. The first class of mutation caused a strong restriction in efficiency of suppression of an amber codon in various cistrons of phage λ and in an alkaline phosphatase structural gene of
E. coli
. The second class caused weak restriction, and the third class caused no restriction. The restrictive effect of the streptomycin resistance mutation of the first class on the
sup E
gene was reduced by addition of streptomycin. This mutation had little effect on efficiencies of suppression by amber suppressor genes
sup D
and
sup F
. Analyses on the alkaline phosphatase formed in the suppressor strain indicated that mutation to restrictive streptomycin resistance causes a reduction in translation of the amber codon in the alkaline phosphatase structural gene.
Metabolism of
d
-Fructose in
Aerobacter aerogenes:
Analysis of Mutants Lacking
d
-Fructose 6-Phosphate Kinase and
d
-Fructose 1,6-Diphosphatase
Authors: Sapico Virginia , Hanson T. E. , Walter R. W. , Anderson R. L.
Published: January 2020

The relative significance of the pathways for the conversion of
d
-fructose to
d
-fructose 1,6-diphosphate via
d
-fructose 1-phosphate or
d
-fructose 6-phosphate in
Aerobacter aerogenes
PRL-R3 was assessed by observing growth patterns of mutants lacking either
d
-fructose 6-phosphate kinase or
d
-fructose 1,6-diphosphatase. The mutant lacking
d
-fructose 6-phosphate kinase grew well on
d
-fructose or glycerol but not on
d
-glucose, whereas the mutant lacking
d
-fructose 1,6-diphosphatase grew on
d
-glucose but not on
d
-fructose or glycerol. The data indicate that the pathway of
d
-fructose metabolism is primarily through
d
-fructose 1-phosphate rather than
d
-fructose 6-phosphate.
Effects of Indomethacin on Acute, Subacute, and Latent Infections in Mice and Rats
Authors: Robinson Harry J. , Phares Herbert F. , Graessle Otto E.
Published: January 2020

The comparative effect of indomethacin and hydrocortisone on the resistance of mice or rats to various acute, subacute, and latent bacterial infections was investigated. Large daily doses of indomethacin and hydrocortisone administered to mice challenged with bacterial pathogens, including
Klebsiella pneumoniae
AD,
Salmonella schottmuelleri
3010,
Staphylococcus aureus
(Smith),
Streptococcus pyogenes
C203,
Salmonella pullorum
#2,
Proteus vulgaris
1810, and
Pseudomonas aeruginosa
2616, revealed that in essentially all of these acute infections, the mortality of the infected mice treated with indomethacin was essentially identical to that found in the infected controls. In contrast, hydrocortisone often lowered the resistance of mice to these acute infections. In a more chronic bacterial infection due to
Corynebacterium kutscheri
, hydrocortisone produced striking deleterious effects on resistance, whereas indomethacin administration in doses approaching the maximal tolerated level caused no observable adverse effects on host resistance. Indomethacin fed continuously to rats for 80 days, at maximal tolerated levels, caused no observable adverse effects on the host-parasite relationship of rats which were shown to harbor various latent infections. Hydrocortisone administration, however, lowered the resistance of rats as evidenced by increased mortality related directly to extensive bacterial infection. Insofar as infection is concerned, indomethacin behaved like other nonsteroid anti-inflammatory agents such as aspirin and phenylbutazone.
Response of Cultured Mammalian Cells to Diphtheria Toxin III. Inhibition of Protein Synthesis Studied at the Subcellular Level
Authors: Moehring Thomas J. , Moehring Joan M.
Published: January 2020

Diphtheria toxin inhibited protein synthesis in intact KB cells. The action of the toxin upon the cell did not result in disaggregation of polyribosomes, or in impairment of their ability to function in protein synthesis. A reduction in single ribosomes and a concomitant increase in polyribosomes did result from the action of toxin. Nascent peptides were not cleaved from polyribosomes by the action of toxin, but treatment of fully intoxicated cells with puromycin resulted in cleavage of these peptides, and caused accelerated polyribosome breakdown. Our data indicated that the toxin must enter the cell to exert its effect. The component or components sensitive to toxin were localized in the 100,000 ×
g
supernatant fraction of cytoplasmic extracts. When extracts from intoxicated cells were treated with nicotinamide, a significant proportion of their capacity to synthesize protein was restored. The specificity of this reaction suggested that nicotinamide adenine dinucleotide is involved in the action of toxin in the intact cell, and that one component inactivated by toxin is soluble transferase II.
Factors Affecting the Rate of Heat-induced Spore Germination inDictyostelium discoideum
Authors: Cotter David A. , Raper Kenneth B.
Published: January 2020

Washed spores ofDictyostelium discoideum, strains NC-4H, NC-4D, and V-12, germinated rapidly after being heat shocked at or near 45.0 C for 30 min. Cultures of the slime molds were grown in association withEscherichia coliB/r as the host bacterium; spores taken from plates of synthetic medium had a higher final germination value than spores from complex medium containing peptone and yeast extract. Young spores germinated more rapidly than older spores. Optimal germination occurred betweenpH 6.0 and 7.0, and, of the buffers tested, potassium phosphate allowed the most rapid germination. After heat shocking, spores were diluted into fresh oxygenated buffer to provide enough oxygen for completion of germination. Germination occurred most rapidly between incubation temperatures of 22 and 25 C.