bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence for the Involvement of Membranous Bodies in the Processes Leading to Genetic Transformation in
Bacillus subtilis
Authors: Wolstenholme David R. , Vermeulen Cornelius A. , Venema Gerhardus
Published: January 2020

Wolstenholme, David
R. (Max-Planck-Institut für Biologie, Tübingen, Germany),
Cornelius A. Vermeulen, and Gerhardus Venema
. Evidence for the involvement of membranous bodies in the processes leading to genetic transformation in
Bacillus subtilis
. J. Bacteriol.
92:
1111–1121. 1966.—Data obtained from electron microscopic autoradiographs of profiles of cells of a
Bacillus subtilis
population exposed to H
3
-thymidine-labeled donor deoxyribonucleic acid (DNA) during the phase of maximal competence indicated that molecules originating from absorbed DNA are closely associated with membranous bodies, particularly with those situated in the cytoplasm, but that most if not all of the radioactive molecules are outside the bodies. It is suggested that membranous bodies produce enzymes essential to the eventual incorporation of transforming DNA into the bacterial genome, or to the breakdown and utilization or expulsion of absorbed DNA not incorporated as transformant (or to both processes). During the phase of maximal competence, the total number of membranous bodies seen in profiles increased continuously to as much as 2.3 times the numbers found during earlier stages of culture. This increase was not accounted for by a decrease in bacterial cell volume, but resulted from an actual increase in total volume of membranous bodies. The number of membranous bodies visibly connecting plasma membrane and nuclear region increased during maximal competence to as much as 30 times the numbers found in earlier stages. As both increases were found in the absence of donor DNA and only began after maximal competence was attained, it seemed most probable that they were an expression of a physiological state influenced by the continuing deficiency of nutrients in the growth medium during this phase of culture.
Desulfovibrio africanus
sp. n., a New Dissimilatory Sulfate-reducing Bacterium
Authors: Campbell L. Leon , Kasprzycki Mary A. , Postgate John R.
Published: January 2020

Campbell, L. Leon
(University of Illinois, Urbana),
Mary A. Kasprzycki, and John R. Postgate
.
Desulfovibrio africanus
sp. n., a new dissimilatory sulfate-reducing bacterium. J. Bacteriol.
92:
1122–1127. 1966.—The strains Benghazi and Walvis Bay can be distinguished from 40 strains of
Desulfovibrio
and from
D. gigas
on the basis of morphological and immunological studies. Electron microscopy revealed polar lophotrichous flagellation similar to that of
D. gigas
but different from the characteristic single polar flagellum of the 40 strains of
Desulfovibrio
. Immunological evidence shows that the two strains are related to members of the genus
Desulfovibrio
but possess several common antigenic components not present in the other strains tested. The deoxyribonucleic acid of both strains has a buoyant density of 1.724 g/cc and a guanine plus cytosine content of 60.2%. Cell-free extracts of both organisms show absorption bands of cytochrome
c
3
and desulfoviridin, characteristic for
Desulfovibrio
. The two organisms carry out the sulfate-linked lactate fermentation and neither will grow in the absence of sulfate. Both strains contain the enzymes of the dissimilatory pathway of sulfate reduction. Therefore, these studies have demonstrated that the Benghazi and Walvis Bay strains should be regarded as taxonomically distinct from other species of
Desulfovibrio
.
Effect of Avian Myeloblastosis Virus in the Japanese Quail
Authors: Moscovici Carlo , Macintyre E. H.
Published: January 2020

Moscovici, Carlo
(University of Colorado Medical Center, Denver),
and E. H. Macintyre
. Effect of avian myeloblastosis virus in the Japanese quail. J. Bacteriol.
92:
1141–1149. 1966.—Avian myeloblastosis virus (AMV) induced a spectrum of neoplasms in Japanese quail (
Coturnix coturnix japonica
) which was similar to that observed in the chicken, with one exception: the total absence of acute myeloblastic leukemia in quail. Studies in vivo as well as in vitro suggested that the cause for this difference may be ascribed to the heterogeneity of AMV and to the genetic makeup of the quail cell.
Clumping of
Staphylococcus aureus
in the Peritoneal Cavity of Mice
Authors: Kapral Frank A.
Published: January 2020

Kapral, Frank
A. (Philadelphia General Hospital, Philadelphia, Pa.). Clumping of
Staphylococcus aureus
in the peritoneal cavity of mice. J. Bacteriol.
92:
1188–1195. 1966.—Nonencapsulated strains of
Staphylococcus aureus
inoculated into the peritoneal cavity of mice are promptly clumped by the interaction of fibrinogen with the bound coagulase present on the bacterial surface. Some of the pre-existing leukocytes adhere to the staphylococcal clumps during the 1st hr, but phagocytosis is minimal. During the 2nd hr, there is an influx of neutrophils into the region, and these form a thick layer around the staphylococcal clumps and, apparently, prevent further egress of toxin. Leukocytes in proximity to the organisms undergo degeneration, but cells located externally maintain an effective barrier and, thus, confine the organisms. The encapsulated Smith strain of
S. aureus
is not clumped under these circumstances, presumably because the capsule prevents the bound coagulase-fibrinogen interaction.
Metabolic Control of Intracellular Proteolysis in Growing and Resting Cells of
Escherichia coli
Authors: Pine Martin J.
Published: January 2020

Pine, Martin
J. (Roswell Park Memorial Institute, Buffalo, N.Y.). Metabolic control of intracellular proteolysis in growing and resting cells of
Escherichia coli
. J. Bacteriol.
92:
847–850. 1966.—Protein breakdown was examined in
Escherichia coli
under varying conditions of growth and during nutritional deprivation. Optimal breakdown rates, estimated over short time periods of protein synthesis and decay, are invariant and unrepressible by any condition of growth or starvation. A more important aspect of metabolic control is manifest in the selection imposed by the physiological state of the cell for breakdown of limited populations of proteins. During the progress of growth, one-half to three-quarters of the protein susceptible in the resting state is progressively spared, and breakdown is continued in populations that are more selected and more frequently regenerated.
Influence of Phosphate Starvation on Cultures of
Pseudomonas aeruginosa
Authors: Hou Cynthia I. , Gronlund Audrey F. , Campbell J. J. R.
Published: January 2020

Hou, Cynthia
I. (University of British Columbia, Vancouver, B.C., Canada),
Audrey F. Gronlund, and
J. J. R.
Campbell
. Influence of phosphate starvation on cultures of
Pseudomonas aeruginosa
. J. Bacteriol. 92:851–855. 1966.—The changes occurring in
Pseudomonas aeruginosa
during phosphate starvation in a phosphate-deficient medium were assessed by measuring alterations in optical density, viable-cell count, chemical composition, and ribosome patterns. After a 24-hr period of starvation, optical density, protein, and deoxyribonucleic acid per milliliter of culture increased, whereas ribonucleic acid decreased. Extensive ribosomal degradation was apparent from sucrose density gradient centrifugation patterns. The induction of an alkaline phosphomonoesterase during phosphate starvation was observed. A linear response of phosphate-starved cells to low levels of phosphate supplied exogenously was evident from optical-density measurements, and a threshold requirement for phosphate analogous to the “energy of maintenance” was not detected.
Interferon Production by Inactivated Newcastle Disease Virus in Cell Cultures and in Mice
Authors: Youngner Julius S. , Scott Anne W. , Hallum Jules V. , Stinebring Warren R.
Published: January 2020

Youngner, Julius S
. (University of Pittsburgh, Pittsburgh, Pa.),
Anne W. Scott, Jules V. Hallum, and Warren R. Stinebring
. Interferon production by inactivated Newcastle disease virus in cell cultures and in mice. J. Bacteriol.
92:
862–868. 1966.—A comparison was made of the effects of ultraviolet (UV) irradiation or heating at 56 C on the interferon-stimulating capacity of Newcastle disease virus in primary chick embryo fibroblast (CE) cultures, in L-cell cultures, and in the intact mouse. The data obtained indicated the critical importance of the host cell system used for interferon production. Virus inactivated by UV irradiation, as well as infective virus, was an effective stimulus of interferon production in L cells and in mice, and this property persisted on continued irradiation. In contrast, in CE cell cultures, infective virus produced no interferon, whereas UV-irradiated virus produced maximal interferon titers when all infectivity was destroyed; continued irradiation resulted in a rapid loss of the interferon-stimulating capacity of the virus. Virus inactivated at 56 C did not produce interferon in CE or L-cell cultures. In the intact mouse, on the other hand, heat-inactivated virus was capable of stimulating the release of significant levels of circulating interferon.
Factors Influencing Protection Against Experimental Tuberculosis in Mice by Heat-Stable Cell Wall Vaccines
Authors: Ribi E. , Anacker R. L. , Brehmer W. , Goode G. , Larson C. L. , List R. H. , Milner K. C. , Wicht W. C.
Published: January 2020

Ribi, E. (Rocky Mountain Laboratory, Hamilton, Mont.), R. L.Anacker, W. Brehmer, G. Goode, C. L. Larson, R. H. List, K. C. Milner, and W. C. Wicht. Factors influencing protection against experimental tuberculosis in mice by heat-stable cell wall vaccines. J. Bacteriol.92:869–879. 1966.—Studies of nonviable, heat-stable vaccines for active protection against experimental tuberculosis have been continued with a test involving aerosol challenge of intravenously vaccinated mice. The previously reported activating effect of light mineral oil on disrupted cells of the BCG strain was found to be shared by certain other mineral oils and a synthetic, 24-carbon hydrocarbon, but not by kerosene or any of several vegetable oils. Dry cell walls coated with a small amount of oil and dispersed in saline with aid of an emulsifier were suitable for intravenous administration and were effective in promoting resistance to challenge. Oil used in this manner, in contrast to water-in-oil emulsions of the Freund type which could not be administered intravenously, did not potentiate the tuberculin-sensitizing activity of the cell walls. Although the amount of oil required for full effect was small (< 0.5 ml/100 mg of dry antigen), there was a critical level below which optimal enhancement was not achieved. More stable suspensions than could be obtained with the other oils were readily prepared from cell walls treated with the synthetic hydrocarbon, 7-n-hexyloctadecane. Extended experience has shown that in this test system both the viable BCG standard vaccine and heated, oil-treated experimental vaccines gave highly reproducible results showing graded responses to graded doses.
Immunoelectrophoretic Studies of Sera from Rabbits Experimentally Infected withHistoplasma capsulatum
Authors: Adamson David M. , Cozad George C.
Published: January 2020

Adamson, DavidM. (University of Oklahoma, Norman),and George C. Cozad. Immunoelectrophoretic studies of sera from rabbits experimentally infected withHistoplasma capsulatum. J. Bacteriol.92:887–891. 1966.—In a study involving 24 mature Dutch rabbits inoculated intravenously with 2.6 × 108Histoplasma capsulatumyeast cells per kg of body weight, all rabbits were shown to develop precipitins by the end of the 5th week. Precipitins were demonstrated both by the micro-Ouchterlony method and microimmunoelectrophoresis with the use of concentrated histoplasmin as the antigen. The latter technique proved to be the more sensitive. The 10 × concentrate of histoplasmin gave better precipitin patterns than did the 5 × concentrate. Agglutinins were formed by 90% of the rabbits by the end of the 4th week, as shown by the capillary tube agglutination test. Three precipitin bands, arbitrarily designated A, B, and C, were demonstrated by immunoelectrophoresis with use of the sera of the test animals. Band A occurred between the 1st and 2nd weeks after inoculation and was, for a period, present in 100% of the sera of the test animals. Band A occurred separately or in conjunction with band B or B and C, and it persisted longer than these other two bands. Bands B and C appeared between the 3rd and 4th weeks and were found, by the end of the 5th week, in 35 and 15%, respectively, of the sera tested. They were never seen separately or together without the presence of band A. Band C disappeared by the end of the 6th week, and band B, by the 10th week, but band A was still present in 19% of the sera at the end of 10 weeks.
Studies on Cytotropism in Animal Viruses III. Growth of Influenza Virus in Epithelial-like and Fibroblastic Cells Derived from Chick Embryo Lung
Authors: Stewart Robert B. , Frickey Paul H.
Published: January 2020

Stewart, RobertB. (University of Rochester, Rochester, N.Y.),and Paul H. Frickey. Studies on cytotropism in animal viruses. III. Growth of influenza virus in epithelial-like and fibroblastic cells derived from chick embryo lung. J. Bacteriol.92:972–977. 1966.—Growth of the PR8 strain of influenza virus was studied in epithelial-like and fibroblastic cell cultures derived from chick embryo lungs. The cells were found to differ in morphology, staining characteristics, and in their ability to support production of infectious influenza virus. Fibroblastic cells were characterized by their spindle shape, content of a mucopolysaccharide, their relative inability to synthesize infectious influenza virus, and production of a cell-associated noninfectious hemagglutinin. Epithelial-like cells were characterized by their polygonal shape, absence of mucopolysaccharide, and ability to synthesize infectious influenza virus.
Enzymes in Glycolysis and the Citric Acid Cycle in the Yeast and Mycelial Forms of
Paracoccidioides brasiliensis
Authors: Kanetsuna Fuminori , Carbonell Luis M.
Published: January 2020

Kanetsuna, Fuminori
(Instituto Venezolano de Investigaciones Cientificas, Caracas, Venezuela),
and Luis M. Carbonell
. Enzymes in glycolysis and the citric acid cycle in the yeast and mycelial forms of
Paracoccidioides brasiliensis
. J. Bacteriol.
92:
1315–1320. 1966.—Enzymatic activities in glycolysis, the hexose monophosphate shunt, and the citric acid cycle in cell-free extracts of the yeast and mycelial forms of
Paracoccidioides brasiliensis
were examined comparatively. Both forms have the enzymes of these pathways. Activities of glucose-6-phosphate dehydrogenase and malic dehydrogenase of the mycelial form were higher than those of the yeast form. Another 15 enzymatic activities of the mycelial form were lower than those of the yeast form. The activity of glyceraldehyde-3-phosphate dehydrogenase showed the most marked difference between the two forms, its activity in the mycelial form being about 20% of that in the yeast form.
Multiplicity Reactivation of Reovirus Particles After Exposure to Ultraviolet Light
Authors: McClain Mary E. , Spendlove Rex S.
Published: January 2020

McClain, Mary
E. (California State Department of Public Health, Berkeley),
and Rex S. Spendlove
. Multiplicity reactivation of reovirus particles after exposure to ultraviolet light. J. Bacteriol.
92:
1422–1429. 1966.—Exposure of reovirus suspensions to moderate doses of ultraviolet light results in essentially exponential inactivation of infectivity to survivals of 10
−2
to 10
−3
. With suspensions of sufficiently high particle concentration, larger doses of ultraviolet light (6 to 12 min) are associated with multiplicity reactivation (MR) which is demonstrable both by immunofluorescent-cell count and by plaque assay in FL human amnion cells. Similar effects are produced by photodynamic inactivation in the presence of proflavine, but not by thermal inactivation at 50 C. All three reovirus types exhibit MR under appropriate conditions, and all three interact in mixed ultraviolet suspensions with high efficiency. Progeny from FL cells infected under conditions of MR were as infectious as those of unirradiated inocula, with yields per cell ranging from 10
4
to 4 × 10
4
infective units.
Effect of Thymine Starvation on Messenger Ribonucleic Acid Synthesis in
Escherichia coli
Authors: Luzzati Denise
Published: January 2020

Luzzati, Denise
(Institut de Biologie Physico-Chimique, Paris, France). Effect of thymine starvation on messenger ribonucleic acid synthesis in
Escherichia coli
. J. Bacteriol.
92:
1435–1446. 1966.—During the course of thymine starvation, the rate of synthesis of messenger ribonucleic acid (mRNA, the rapidly labeled fraction of the RNA which decays in the presence of dinitrophenol or which hybridizes with deoxyribonucleic acid) decreases exponentially, in parallel with the viability of the thymine-starved bacteria. The ability of cell-free extracts of starved bacteria to incorporate ribonucleoside triphosphates into RNA was determined; it was found to be inferior to that of extracts from control cells. The analysis of the properties of cell-free extracts of starved cells shows that their decreased RNA polymerase activity is the consequence of a modification of their deoxyribonucleic acid, the ability of which to serve as a template for RNA polymerase decreases during starvation.
Fluorescent Method for the Detection of Excreted Ribonuclease Around Bacterial Colonies
Authors: Lanyi Janos K. , Lederberg Joshua
Published: January 2020

Lanyi, Janos
K. (Stanford University School of Medicine, Palo Alto, Calif.),
and Joshua Lederberg
. Fluorescent method for the detection of excreted ribonuclease around bacterial colonies. J. Bacteriol.
92:
1469–1472. 1966.—A test for the release of extracellular ribonuclease by
Bacillus subtilis
colonles was developed. The method consists of incorporating acridine orange and ribonucleic acid into nutrient agar plates and viewing the grown bacterial colonies under ultraviolet light. Regions of ribonuclease secretion appear as dark halos around the colonies on a green fluorescent background. The theoretical basis and the utility of this test are discussed.
Exaltation of the Development of Poliovirus by Semicarbazide
Authors: Grossberg Sidney E. , Lwoff Marguerite , Lwoff André
Published: January 2020

Grossberg, Sidney
E. (Institut Pasteur, Paris, France),
Marguerite Lwoff, and André Lwoff
. Exaltation of the development of poliovirus by semicarbazide. J. Bacteriol.
92:
1473–1477. 1966.—Semicarbazide (NH
2
—NH—CO—NH
2
) remarkably increases the development of poliovirus. In single-cycle experiments, semicarbazide (SCZ) acted to (i) diminish the length of the latent period, (ii) increase the rate of production of virions, and (iii) increase the final yield of virus. These effects were demonstrable in KB cells, a human malignant cell line, and other primate cells. The dose range over which the compound exerts its effect was relatively large, i.e., from 0.3 to 20 m
m
, whereas higher concentrations inhibited viral growth. SCZ achieved its exalting effect only when it was added during the first 3 hr of viral development; later addition had no effect. Withdrawal of SCZ at intervals during the viral cycle confirmed that its action occurred within 3 hr after infection. The possible mode of action of SCZ is discussed. SCZ appeared to act, at least in part, by increasing the rate of synthesis of the viral ribonucleic acid.
Lytic Enzyme Produced by
Myxococcus xanthus
Authors: Hart Beth A. , Zahler Stanley A.
Published: January 2020

Hart, Beth A
. (Cornell University, Ithaca, N.Y.),
and Stanley A. Zahler
. Lytic enzyme produced by
Myxococcus xanthus
. J. Bacteriol.
92:
1632–1637. 1966.—Strain FBa of
Myxococcus xanthus
releases into its culture medium an enzyme capable of lysing
Micrococcus lysodeikticus
cells and of releasing
N
-acetyl amino sugars from their cell walls. The lysin is stable at
p
H values near neutrality and at temperatures below 50 C. It lyses a number of bacterial species sensitive to egg-white lysozyme, and fails to lyse lysozyme-resistant species. Sensitivity of
M. lysodeikticus
cell walls to FBa lysin and to lysozyme is changed in a similar manner by addition and removal of
O
-acetyl groups. We describe methods for obtaining 190-fold purification of the lysin from culture filtrates, using acetone and ammonium sulfate precipitations and filtration through diethylaminoethyl cellulose. We also describe a gel filtration method for separating the lysin from a protease which is also produced by strain FBa.
Energy Requirement for
l
-Glutamate Uptake and Utilization by
Hansenula subpelliculosa
Cells
Authors: Shieh K. Z. , Hedrick L. R.
Published: January 2020

Shieh
, K. Z. (Illinois Institute of Technology, Chicago),
and L. R. Hedrick
. Energy requirement for
l
-glutamate uptake and utilization by
Hansenula subpelliculosa
cells. J. Bacteriol.
92:
1638–1644. 1966.—Cells of the yeast
Hansenula subpelliculosa
require an energy source for the uptake of glutamate. A lag period of 20 to 40 min was required after the addition of glucose to the cells before glutamate uptake was initiated. When cells were preincubated in glucose, and washed with distilled water prior to the addition of glutamate, there was no lag period. Preincubation in glucose and glutamate lowered both the rate and the total uptake of glutamate as compared with cells preincubated in glucose alone. This is attributed to the partial utilization of the glucose-metabolite by glutamate or to the partial saturation of binding sites by glutamate during the preincubation period. Transport of glutamate by these yeast cells appears to be via a carrier, where energy is required for the binding of the amino acid to nonspecific binding sites. In addition to total uptake, some aspects of the
C
14
-glutamate utilization were measured. Of the total uptake, 58% was metabolized and converted to CO
2
, 25.2% remained in the soluble pool, and 16.8% was incorporated into trichloroacetic acid-insoluble products. When the available energy source was depleted, the processes of uptake, metabolism, and incorporation ceased, even though there was an ample supply of glutamate present within the cells. Removal of cells from glutamate and addition of glucose reinitiated the incorporation of glutamate into proteins and other trichloroacetic acid-insoluble compounds. Therefore, an additional energy source is required with this species of yeast for glutamate uptake, for the priming of mechanisms required for its metabolism, and for its incorporation.
Streptomycin and Infection of
Escherichia coli
by T6r
+
Bacteriophage
Authors: Freda Celia E. , Cohen Seymour S.
Published: January 2020

Freda, Celia
E. (University of Pennsylvania School of Medicine, Philadelphia),
and Seymour S. Cohen
. Streptomycin and infection of
Escherichia coli
by T6r
+
bacteriophage. J. Bacteriol.
92:
1670–1679. 1966.—The thymineless, histidineless, uracil-less
Escherichia coli
15 THU was shown to be sensitive to streptomycin, dying in patterns comparable to that of strain 15 TAU in the presence or absence of the required amino acid histidine. In the absence of histidine, the antibiotic stimulated ribonucleic acid (RNA) synthesis without a detectable inhibition or stimulation of deoxyribonucleic acid (DNA) synthesis. In the presence of streptomycin (40μg/ml) under conditions of multiple infection with T6r
+
, lysis of THU occurred 1 hr earlier than did the control, having produced about one-third as much DNA and phage as did the control. In the absence of histidine, thereby preventing synthesis of phage DNA, accumulation of virus-induced RNA was similar for about 30 min in control and streptomycin-treated systems. In the presence of the antibiotic, however, the infected cells accumulated about 50 to 70% more RNA than did the control after 90 min. Nevertheless, the turnover of RNA was not detectably affected by streptomycin. The rate of production and final amount of deoxycytidylate hydroxymethylase, as well as the cut off time of synthesis of this enzyme, were scarcely affected by streptomycin. The beginning of DNA synthesis was delayed about 3 to 4 min by the antibiotic. The incorporation of histidine in infected cells was unaffected for 10 min and was only about 10% less than the control at 70 min. Lysozyme production began at about 10 min in control and antibiotic-treated systems, continued at essentially similarly increasing rates for 20 min, but stopped abruptly in the streptomycin-treated cells despite continuing protein synthesis. With the exception of lysozyme, the production of phage-specific polymers in a streptomycin-sensitive bacterium was only slightly affected by the antibiotic.
Metabolism of
d
-Mannose in
Aerobacter aerogenes
: Evidence for a Cyclic Pathway
Authors: Kamel M. Y. , Anderson R. L.
Published: January 2020

Kamel
, M. Y. (Michigan State University, East Lansing),
and R. L. Anderson
. Metabolism of
d
-mannose in
Aerobacter aerogenes
: evidence for a cyclic pathway. J. Bacteriol.
92:
1689–1697. 1966.—Evidence is presented which suggests a cyclic pathway for the constitutive utilization of
d
-mannose in extracts of
Aerobacter aerogenes
PRL-R3.
d
-Mannose is phosphorylated with
d
-glucose-6-phosphate to yield
d
-mannose-6-phosphate and
d
-glucose.
d
-Glucose-6-phosphate may be regenerated by isomerization of
d
-mannose-6-phosphate through
d
-fructose-6-phosphate, or by phosphorylation of
d
-glucose with adenosine-5′-triphosphate. The pathway involves the participation of four constitutive enzymes:
d
-glucose-6-phosphate isomerase,
d
-mannose-6-phosphate isomerase, a stereospecific
d
-glucokinase, and a phosphotransferase which phosphorylates
d
-mannose with
d
-glucose-6-phosphate, acetyl phosphate, or carbamyl phosphate. The absence of
d
-mannokinase (adenosine-5′-triphosphate:
d
-mannose phosphotransferase) activity in extracts of this organism suggests that the pathway may be of functional significance. Also, the pathway accounts for an apparent 2-epimerization of
d
-mannose to
d
-glucose that was observed in extracts.
Inhibition of Coliphage Reproduction after Superinfection of Induced Lysogens
Authors: Brenner Don J. , Groman Neal B.
Published: January 2020

Brenner, Don
J. (University of Washington, Seattle),
and Neal B. Groman
. Inhibition of coliphage reproduction after superinfection of induced lysogens. J. Bacteriol.
92:
1727–1734. 1966.—Purified preparations of phages λ and λ112 inhibited lysis, phage reproduction, and endolysin synthesis by ultraviolet-induced strains of K-12 (λ) and K-12 (λ112). Structural and partial functional integrity of phage was required for inhibition, and the role of phage deoxyribonucleic acid (DNA) in inhibition was demonstrated. Both ultraviolet-irradiated and host-modified lysates of λ were inhibitory, suggesting that replication of superinfecting phage DNA was not essential for inhibition. Using various combinations of superinfecting and resident phage, including λ, 434, 434hy, and
C
-mutant derivatives, we observed that all three
C
region cistrons played some role in inhibition. Of the three, the
C
1
cistron was the most critical. With certain phage combinations, inhibition was observed even though the resident and superinfecting phage differed in immune specificity. Both the medium and the method of superinfection determined whether lysis or lysis inhibition would occur. These and other observations with K-12(λ)
thy
−
indicated that many factors influence the outcome of superinfection. The data are compatible with the view that superinfection inhibition is due to the establishment or re-establishment of phage repressor activity, with the result that replication of both superinfecting and resident phage is blocked.
Effect of Spermine on Lysis and Reproduction by Bacteriophages φX174, λ, and f
2
Authors: Groman Neal B. , Suzuki Grace
Published: January 2020

Groman, Neal
B. (University of Washington, Seattle),
and Grace Suzuki
. Effect of spermine on lysis and reproduction by bacteriophages φX174, λ, and f
2
. J. Bacteriol.
92:
1735–1740. 1966.—A test was made of the hypothesis that lysis by all bacteriophages shares as a common and critical step an alteration in the osmotic stability of the infected cell. This was done by examining the effect of spermine on lysis. Spermine is one of a number of compounds which can stabilize spheroplasts and protoplasts to lysis in distilled water. Spermine stabilized both φX174- and f
2
-infected cells at concentrations ranging from 2 × 10
−3
to 4 × 10
−2
m
, but failed to stabilize λ-infected cells at concentrations up to 8 × 10
−2
m
. Stabilization was reflected both in optical density measurements and in the retention of mature phage in structures sedimentable at low speeds. At optimal concentration, over 90% of the phage was retained in these structures. These data suggest that the mechanism of lysis by φX174 and f
2
differs sharply from that caused by λ, and other observations suggest that there are differences in the lytic process of φX174 and f
2
as well. Spermine also displayed a differential effect on phage reproduction. The reproduction of λ and f
2
was inhibited by spermine, though the data do indicate that maturation occurs in its presence. The reproduction of φX174 was enhanced by spermine.
Serological Comparison of the Three Morphological Phases ofCoccidioides immitisby the Agar Gel Diffusion Method
Authors: Landay Marshall E. , Wheat Robert W. , Conant Norman F. , Lowe Edwin P.
Published: January 2020

Hyperimmune sera against spherules and against arthrospores ofCoccidioides immitiswere prepared by inoculation of rabbits. The antibody content of these sera was studied by the agar gel diffusion method. It was observed that antispherule pooled sera formed multiple precipitin bands with extracts of spherules and of arthrospores. The antiarthrospore pooled serum, however, failed to precipitate with the spherule extract, and formed a single band in the presence of an arthrospore solution. When the spherule and the arthrospore extracts were tested with a variety of different antisera, it was observed that the spherule preparation formed bands only in combination with anti-purified spherule pooled serum, whereas the arthrospore extract precipitated with anti-purified spherule, antiarthrospore, and anti-Histoplasma capsulatumpooled sera. It was also observed that a spherule culture supernatant solution formed five precipitin bands in combination with anti-spherule pooled sera, formed one band with pooled antiserum from rabbits with coccidioidomycosis, and did not precipitate in the presence of antiarthrospore pooled serum. Coccidioidin, however, formed two bands in the presence of any of these antisera. It was therefore concluded that extracts from the spherule phase ofC. immitisdiffered from solutions obtained from the arthrospore and mycelial phases.
X-Ray Diffraction Studies on Selected Bacterial Cell Walls
Authors: Carito Sebastian L. , Bazil Stephen L. , DiGiacomo Giulio
Published: January 2020

The cell walls of selected bacteria were studied by X-ray diffraction analysis to determine and characterize crystalline components. The walls were isolated by mechanical disruption and purified by enzymatic and washing procedures. The X-ray diffraction lines which appeared from the gram-positive cell walls were shown to be due to the constituent “mucopeptide” fraction. No diffraction lines could be obtained from the gram-negative bacterium studied. The results show that crystallinity is associated with mucopeptide.
Purification and Characterization of Yeast β-Glucosidases
Authors: Fleming Leslie W. , Duerksen Jacob D.
Published: January 2020

Constitutive β-glucosidases from
Saccharomyces fragilis
(Y-18) and
S. dobzhanskii
(Y-19) precipitated at the same concentration of ammonium sulfate. The partially purified enzymes had similar activation energies, molecular weights, affinities for certain natural and synthetic β-glucosides, and optimal
p
H values for substrate hydrolysis, and they were stable over approximately the same
p
H range. The enzymes, however, could be clearly distinguished by other criteria. Affinities of the synthetic, sulfur-containing β-glucosides for Y-18 enzyme were many times greater than for Y-19 enzyme. The latter enzyme was more resistant to heat. The two enzymes eluted from diethylaminoethyl cellulose at different concentrations of sodium chloride. In precipitin tests, homologous enzyme-antisera systems were highly specific. The β-glucosidase synthesized by a hybrid,
S. fragilis
×
S. dobzhanskii
(Y-42), was unique. Characterization of this enzyme produced values which were intermediate to those for the enzymes from the parental yeast strains. Heat-inactivation slopes and Lineweaver-Burk plots for the Y-42 enzyme were anomalous. It is suggested that hydrolytic activity in Y-42 preparations is due to a spectrum of hybrid enzyme molecules composed of varying amounts of two distinct polypeptides. It is further suggested that these polypeptides may be identical to those synthesized by the parental Y-18 and Y-19 yeast strains.
Evidence for Multiple Molecular Forms of Yeast β-Glucosidase in a Hybrid Yeast
Authors: Fleming Leslie W. , Duerksen Jacob D.
Published: January 2020

A mixture of β-glucosidases from
Saccharomyces fragilis
(Y-18) and
S. dobzhanskii
(Y-19) eluted from diethylaminoethyl cellulose in two peaks, whereas the enzyme from a hybrid,
S. fragilis
×
S. dobzhanskii
(Y-42), eluted in a single broad peak. The highest Y-42 activity fractions eluted at a sodium chloride molarity which was intermediate to the molarities at which most of the Y-18 and Y-19 activity was eluted. In cellulose polyacetate strips, Y-42 enzyme migrated as a diffuse band which spanned the distances migrated by the enzymes from the parent yeast strains. Antisera against either Y-18 or Y-19 enzyme precipitated 80 to 90% of Y-42 enzyme activity. When Y-42 enzyme was dissociated by heat or urea and reacted with parental antiserum, a concomitant increase in the opposite parental activity was demonstrable in both precipitation and complement-fixation (CF) tests. Urea-dissociated β-glucosidases were resolvable by sucrose-gradient centrifugation into multiple bands displaying specific CF activity. When the enzymes were exposed to 4
m
urea for 12 min, particles of approximately 110,000 molecular weight were obtained. By extending the exposure time to 40 min, and incorporating 0.5
m
urea in the gradients, smaller particles were detected with molecular weights ranging from 18,000 to 23,000. Attempts to regenerate enzyme activity after dissociation with urea were only moderately successful. Results suggested that a slightly acidic environment favored reassociation, as did the presence of 2-mercaptoethanol. Residual urea also seemed important. It is proposed that the structural genes for both Y-18 and Y-19 enzyme are present in Y-42 cells with either independent or closely interacting regulatory mechanisms. Since synthesis of the two parental-type polypeptides may be unequal, the availability of enzyme subunits for subsequent polymerization in the cell cytoplasm might be equalized at the polysome level. Random association of subunits would produce a binomial distribution of true hybrid enzyme molecules.
In Vitro Assay of Endotoxin by the Inhibition of Macrophage Migration
Authors: Heilman Dorothy H. , Bast Robert C.
Published: January 2020

A quantitative in vitro technique was used to compare the ability of different endotoxins to inhibit the migration of macrophages from explants of rabbit spleen cultured in a coagulated plasma medium. The order of potency was different from that observed in chick embryo assays, and in assays with mice, of the same endotoxins. In general, however, the sensitivity of the macrophage inhibition test was comparable to that of other bioassay methods. A highly purified endotoxin fromSalmonella enteritidis(Ribi) in a concentration of 0.004 μg/ml regularly inhibited macrophage migration. The in vitro method was used to detect a progressive loss of biological activity in fractions obtained during acid hydrolysis of the purified endotoxin. The selective toxicity of very low concentrations of endotoxin for mammalian macrophages was important in estimating the degree of specificity of the reaction. The pattern of cellular response in explant cultures made it possible to differentiate endotoxic damage from the specific cytotoxic action of antigen associated with delayed hypersensitivity.
Induction byl-Tryptophan and an Analogue, α-Methyl-dl-Tryptophan, of the Enzymes Catabolizingl-Tryptophan inPseudomonas
Authors: Tremblay G. C. , Gottlieb J. A. , Knox W. E.
Published: January 2020

An investigation was made of the pattern of induction of the enzymes that metabolizel-tryptophan through kynurenic acid (the quinoline pathway) inPseudomonas fluorescens. The first four enzymes in the pathway were not induced in the same proportions or in the same time courses. This lack of coordinate induction excludes a mechanism of regulation of these enzymes at a single site as proposed in the operon model. The enzymes were induced in a sequential pattern in the order of their position on the pathway, when they became the limiting reactions. The nonmetabolizable analogue, α-methyl-dl-tryptophan, caused a measurable elevation in the levels of the first three enzymes of the same pathway. Evidence is presented that growth of the cells in the presence of α-methyl-dl-tryptophan caused the accumulation of endogenous tryptophan, and that induction by the nonmetabolizable analogue is induction by the endogenous tryptophan.
Complex Lipids of
Rhodomicrobium vannielii
Authors: Park Chong-Eel , Berger Leslie R.
Published: January 2020

Eight components, seven of which contained phosphorus, were found in the phospholipid fraction of
Rhodomicrobium vannielii
. The major components were lipoamino acid (
o
-ornithine ester of phosphatidyl glycerol, 46.5%) and phosphatidyl choline (26.5%). The other six components were phosphatidyl glycerol (9.7%), bisphosphatidic acid (6.7%), phosphatidyl ethanolamine (4.5%), phosphatidic acid (1.8%), lysophosphatidyl glycerol-
o
-ornithine ester (3.2%), and
N,N
-ornithine amide of unidentified fatty acid (0.95%). Total phospholipid accounted for 4.2% of cell dry weight. The major fatty acid was vaccenic acid, C
18:1
, which accounted for approximately 90% of the total fatty acids of the complex lipid fraction. The other four fatty acids were C
16:0
(6.25%), C
18:0
(3.8%), C
14:0
(0.7%), and C
16:1
(0.35%). The sulfolipid content was 0.01% of the cell dry weight or 0.14 μmoles per g of dried cells, assuming that its fatty acid component is vaccenic acid. No steroids were detected.
Fatty Acids of Extractable and Bound Lipids of
Rhodomicrobium vannielii
Authors: Park Chong-Eel , Berger Leslie R.
Published: January 2020

Cells of
Rhodomicrobium vannielii
grown at 29 C in a lactate-containing medium were extracted at room temperature with organic solvents. The extractable fraction contained the bulk of the simple lipid (1.87% of cell dry weight) and complex lipids (phospholipids, 4.2%; sulfolipid, 0.01%), coenzyme Q (0.09%), and pigments (carotenoids 1.2%; bacteriochlorophyll, 1.9%). The cell residue contained the bound lipids (nonpolar fatty acid fraction, 1.86%; polar hydroxy fatty acids, 0.49%). The residue also contained poly-β-hydroxybutyric acid (0.2%), which was extracted in boiling chloroform. In both the simple and complex lipids, vaccenic acid (11-octadecenoic acid) was the largest single component (approximately 90% in each fraction). The fatty acids of the bound lipid contained 35% vaccenic acid, even- and odd-numbered saturated and unsaturated straight-chain fatty acids, cyclopropane-, branched-, and α- and β-hydroxy fatty acids. The extractable lipids contained only straight-chain saturated and unsaturated even-numbered fatty acids. Nearly 60% of hydroxy fatty acid fraction was α-hydroxydodecanoic acid (24%) and β-hydroxydodecanoic acid (34.5%). Coenzyme Q was crystallized and identified as Q
9
on the basis of melting point and chromatographic properties. Q
10
had been previously reported.
Sensitivity of
Escherichia coli
to Atabrine Conferred by R Factor and Its Potential Clinical Significance
Authors: Yoshikawa Masanosuke , Sevag M. G.
Published: January 2020

A comparative study of the inhibitory effect of Atabrine on R
−
and R
+
strains of
Escherichia coli
showed that R
+
cells were killed when grown in the presence of Atabrine, whereas R
−
cells were not. It would appear, therefore, that R factor confers sensitivity to Atabrine on the host cells. The “curing” of R factor from R
+
cells by the ultraviolet light-acridine orange method rendered the “cured” cells more resistant than even the parent R
−
cells. The “cured” cells reinfected by R factor were more sensitive than the “cured” cells but less sensitive than the original R
+
cells. After growth once in Atabrine, and even after subcultures in drug-free medium, the growth of R
+
cells in the presence of Atabrine was more rapid than that of the R
−
cells. R
−
cells made resistant by growing them repeatedly in streptomycin, chloramphenicol, tetracycline, and sulfathiazole in succession also showed a higher degree of sensitivity to Atabrine than the original R
−
cells. When mixtures of R
−
and R
+
cells were grown in 120 μg/ml of Atabrine, R
+
cells were killed and the culture consisted predominantly of R
−
cells. A mixture of R
−
and R
+
cells (1:10,000) inoculated into the Atabrine-containing medium and treated 24 hr later with chloramphenicol was completely killed.
Inducible System for the Utilization of β-Glucosides in
Escherichia coli
II. Description of Mutant Types and Genetic Analysis
Authors: Schaefler S. , Maas W. K.
Published: January 2020

Two types of mutants obtained by treating β-
gl
+
cells with nitrosoguanidine are described. One type, β-
gl
+
c
, is constitutive for the biosynthesis of the aryl β-glucoside splitting enzyme(s) and for the β-glucoside permease; the other (β-
gl
+
sal
−
) has lost the capacity to ferment salicin, but has retained the capacity to ferment arbutin and other aryl β-glucosides. By two successive mutational steps, β-
gl
+
sal
−
c
double mutants can be obtained. Determinations of the enzymatic splitting of salicin and
p
-nitrophenyl β-glucoside by β-
gl
+
sal
−
cells and extracts showed that these mutants have lost the capacity to split salicin but do split
p
-nitrophenyl β-glucoside; they possess the β-glucoside permease, and in them salicin is a gratuitous inducer for enzyme and permease biosynthesis. Studies on a β-
gl
+
strain, which splits salicin as well as
p
-nitrophenyl β-glucoside, have shown that the splitting of salicin is more temperature-sensitive than that of
p
-nitrophenyl β-glucoside and other β-glucosides. Other properties of the two activities are similar. Interrupted mating experiments and cotransduction with P1kc phage showed that the genetic determinants of the β-glucoside system map between the
pyrE
and
ile
loci. Three distinct mutational sites were found and are presumed to have the following functions: β-
glA
, a structural gene for an aryl β-glucoside splitting enzyme; β-
glB
, either the structural gene for the β-glucoside-permease or a regulatory gene; and β-
glC
, a regulatory gene (or site).
Escherichia coli
wild-type strains are of the genotype A
+
B
−
C
+
. The β-
gl
+
mutation determining the ability to ferment β-glucosides is considered to be a permease or regulatory mutation, and the resulting genotype is A
+
B
+
C
+
. The β-
gl
+
sal
−
phenotype results from a mutation in the β-
glA
gene (genotype A′ B
+
C
+
), and the constitutive phenotype results from a mutation in the β-
glC
gene, the genotypes A
+
B
+
C
a
and A′ B
+
C
a
corresponding to the phenotypes β-
gl
+
c
and β-
gl
+
sal
−
c
.
Arginine and Ornithine Catabolism by
Clostridium botulinum
Authors: Mitruka Brij M. , Costilow Ralph N.
Published: January 2020

Clostridium botulinum
62-A was shown to catabolize
l
-arginine via citrulline to ornithine, NH
3
, and CO
2
. The individual enzymes of the dihydrolase system were all demonstrated in extracts of cells, spores, and germinated spores. There was no liberation of urea from
l
-arginine, so no functional arginase enzyme is present, but there was some transamidinase activity in cell extracts.
l
-Ornithine was degraded at a significant rate by cells grown in an
l
-ornithine-supplemented medium; it was partially decarboxylated to putrescine and partially fermented to NH
3
, CO
2
, volatile acids, and δ-aminovaleric acid. Results from the fermentation of
l
-ornithine-
C
14
, -
1-C
14
, and -
2-C
14
demonstrated that essentially all of the CO
2
was derived from carbon 1, and volatile acids from carbons 2 to 5. Assays for the products of
l
-ornithine-
C
14
fermentation revealed that the volatile acids consisted of acetate, propionate, valerate, and butyrate (in order of decreasing concentrations), and that δ-amino-valerate was the primary reduced product. A small amount of citrulline was formed during the fermentation. The carbon and redox balances indicated that
l
-ornithine is fermented as a single substrate. Preliminary experiments demonstrated that the fermentation of
l
-ornithine is carried out by cell extracts with the production of volatile acids.
Purification and Properties of Penicillin Amidase from
Bacillus megaterium
Authors: Chiang C. , Bennett R. E.
Published: January 2020

A penicillin amidase, obtained from the exogenous medium of a
Bacillus megaterium
culture, was purified approximately 96-fold by means of two cycles of adsorption on, and elution from, Celite, followed by a further fractionation on carboxymethylcellulose. On the basis of sedimentation centrifugation analysis, the final preparation was deemed to be homogeneous with an apparent molecular weight of approximately 120,000. The enzyme is specific for benzylpenicillin and has a
p
H optimum between 8 and 9. Complete hydrolysis of benzylpenicillin was obtained at low substrate concentrations. At higher substrate concentrations, the hydrolysis of benzylpenicillin was incomplete, apparently due to enzyme inhibition by phenylacetic acid and 6-aminopenicillanic acid, which were formed during the hydrolysis. Under the assay conditions, phenylacetic acid was a competitive inhibitor of penicillin amidase with an inhibitor constant (
K
i
) of 0.45
m
, whereas 6-aminopenicillanic acid was noncompetitive in nature with a
K
i
of 2.6 × 10
−2
m
. The Michaelis constant of this enzyme was found to be 4.5 × 10
−3
m
when benzylpenicillin was used as substrate.
Qualitative Differences in the Behavior of Pneumococcal Deoxyribonucleic Acids Transforming to the Same Capsular Type
Authors: Bernheimer Harriet P. , Wermundsen Ingbritt E. , Austrian Robert
Published: January 2020

A method is described for estimating quantitatively the frequency of transformation of pneumococci to new capsular types. It is found that, when S-
III
cells are exposed to deoxyribonucleic acid (DNA) from wild-type I strains, transformation to SI occurs at a frequency 20 to 60 times that of transformation to the binary type SI-III. SI markers on DNA isolated from binary strains behave qualitatively and quantitatively in a different manner from the same markers on DNA from wild-type I strains and will transform S-
III
cells only to SI-III. Strains are described which produce only one capsular polysaccharide, but which are genetically binary and carry a second capsular genome with a mutated gene so that the second polysaccharide is not produced. Stability and other characteristics of binary strains are discussed, and one hypothesis for the genetic organization of binary strains is presented.