bluuebunny/crossref_metadata_2025 huggingface dataset:
An Autoregulatory Circuit Affecting Peptide Signaling in
Bacillus subtilis
Authors: Lazazzera Beth A. , Kurtser Iren G. , McQuade Ryan S. , Grossman Alan D.
Published: December 2019

The competence and sporulation factor (CSF) of
Bacillus subtilis
is an extracellular pentapeptide produced from the product of
phrC
. CSF has at least three activities: (i) at low concentrations, it stimulates expression of genes activated by the transcription factor ComA; at higher concentrations, it (ii) inhibits expression of those same genes and (iii) stimulates sporulation. Because the activities of CSF are concentration dependent, we measured the amount of extracellular CSF produced by cells. We found that by mid-exponential phase, CSF accumulated to concentrations (1 to 5 nM) that stimulate ComA-dependent gene expression. Upon entry into stationary phase, CSF reached 50 to 100 nM, concentrations that stimulate sporulation and inhibit ComA-dependent gene expression. Transcription of
phrC
was found to be controlled by two promoters: P1, which precedes
rapC
, the gene upstream of
phrC
; and P2, which directs transcription of
phrC
only. Both RapC and CSF were found to be part of autoregulatory loops that affect transcription from P1, which we show is activated by ComA∼P. RapC negatively regulates its own expression, presumably due to its ability to inhibit accumulation of ComA∼P. CSF positively regulates its own expression, presumably due to its ability to inhibit RapC activity. Transcription from P2, which is controlled by the alternate sigma factor ς
H
, increased as cells entered stationary phase, contributing to the increase in extracellular CSF at this time. In addition to controlling transcription of
phrC
, ς
H
appears to control expression of at least one other gene required for production of CSF.
Salmonella typhimurium
LT2 Catabolizes Propionate via the 2-Methylcitric Acid Cycle
Authors: Horswill Alexander R. , Escalante-Semerena Jorge C.
Published: December 2019

We previously identified the
prpBCDE
operon, which encodes catabolic functions required for propionate catabolism in
Salmonella typhimurium
. Results from
13
C-labeling experiments have identified the route of propionate breakdown and determined the biochemical role of each Prp enzyme in this pathway. The identification of catabolites accumulating in wild-type and mutant strains was consistent with propionate breakdown through the 2-methylcitric acid cycle. Our experiments demonstrate that the α-carbon of propionate is oxidized to yield pyruvate. The reactions are catalyzed by propionyl coenzyme A (propionyl-CoA) synthetase (PrpE), 2-methylcitrate synthase (PrpC), 2-methylcitrate dehydratase (probably PrpD), 2-methylisocitrate hydratase (probably PrpD), and 2-methylisocitrate lyase (PrpB). In support of this conclusion, the PrpC enzyme was purified to homogeneity and shown to have 2-methylcitrate synthase activity in vitro.
1
H nuclear magnetic resonance spectroscopy and negative-ion electrospray ionization mass spectrometry identified 2-methylcitrate as the product of the PrpC reaction. Although PrpC could use acetyl-CoA as a substrate to synthesize citrate, kinetic analysis demonstrated that propionyl-CoA is the preferred substrate.
A Single-Ring Mitochondrial Chaperonin (Hsp60-Hsp10) Can Substitute for GroEL-GroES In Vivo
Authors: Nielsen Kåre L. , McLennan Neil , Masters Millicent , Cowan Nicholas J.
Published: December 2019

Chaperonins participate in the facilitated folding of a variety of proteins in vivo. To see whether the same spectrum of target proteins can be productively folded by the double-ring prokaryotic chaperonin GroEL-GroES and its single-ring human mitochondrial homolog, Hsp60-Hsp10, we expressed the latter in an
Escherichia coli
strain engineered so that the
groE
operon is under strict regulatory control. We found that expression of Hsp60-Hsp10 restores viability to cells that no longer express GroEL-GroES, formally demonstrating that Hsp60-Hsp10 can carry out all essential in vivo functions of GroEL-GroES.
NAD-Dependent DNA-Binding Activity of the Bifunctional NadR Regulator of
Salmonella typhimurium
Authors: Penfound Thomas , Foster John W.
Published: December 2019

NadR is a 45-kDa bifunctional regulator protein. In vivo genetic studies indicate that NadR represses three genes involved in the biosynthesis of NAD. It also participates with an integral membrane protein (PnuC) in the import of nicotinamide mononucleotide, an NAD precursor. NadR was overexpressed and purified as a His-tagged fusion in order to study its DNA-binding properties. The protein bound to DNA fragments containing NAD box consensus sequences. NAD proved to be the relevant in vivo corepressor, but full NAD dependence of repressor activity required nucleotide triphosphates. DNA footprint analysis and gel shift assays suggest that NadR binds as a multimer to adjacent NAD boxes. The DNA-repressor complex would sequester a potential RNA polymerase binding site and thereby decrease expression of the
nad
regulon.
Unraveling the Function of Glycosyltransferases in
Streptococcus thermophilus
Sfi6
Authors: Stingele Francesca , Newell John W. , Neeser Jean-Richard
Published: December 2019

Streptococcus thermophilus
Sfi6 produces a texturizing exopolysaccharide (EPS) consisting of a →3)[α-
d
-Gal
p
-(1→6)]-β-
d
-Glc
p
-(1→3)-α-
d
-Gal
p
NAc-(1→3)-β-
d
-Gal
p
-(1→ repeating unit. We previously identified and analyzed a 14.5-kb gene cluster from
S. thermophilus
Sfi6 consisting of 13 genes responsible for its EPS production. Within this gene cluster, we found a central region of genes (
epsE
,
epsF
,
epsG
, and
epsI
) that showed similarity to glycosyltransferases. In this study, we investigated the sugar specificity of these enzymes. EpsE catalyzes the first step in the biosynthesis of the EPS repeating unit. It exhibits phosphogalactosyltransferase activity and transfers galactose onto the lipophilic carrier. The second step is fulfilled by EpsG, which transfers an α-
N
-acetylgalactosamine onto the first β-galactoside. The activity of EpsF was determined by characterizing the EPS produced by an
S. thermophilus epsF
deletion mutant. This EPS consisted of the monosaccharides Gal, Glc, and GalNAc in an approximately equimolar ratio, thus suggesting that
epsF
codes for the branching galactosyltransferase.
epsI
probably codes for the β-1,3-glucosyltransferase, since it is the only glycosyltransferase to which no gene has been assigned and it exhibits similarity to other β-glycosyltransferases. EpsE shows the conserved features of phosphoglycosyltransferases, whereas EpsF and EpsG exhibit the primary structure of α-glycosyltransferases, belonging to glycosyltransferase family 4, whose members are conserved in all major phylogenetic lineages, including the
Archaea
and
Eukaryota
.
Arg-52 in the Melibiose Carrier of
Escherichia coli
Is Important for Cation-Coupled Sugar Transport and Participates in an Intrahelical Salt Bridge
Authors: Franco Peter J. , Wilson T. Hastings
Published: December 2019

Arg-52 of the
Escherichia coli
melibiose carrier was replaced by Ser (R52S), Gln (R52Q), or Val (R52V). While the level of carrier in the membrane for each mutant remained similar to that for the wild type, analysis of melibiose transport showed an uncoupling of proton cotransport and a drastic reduction in Na
+
-coupled transport. Second-site revertants were selected on MacConkey plates containing melibiose, and substitutions were found at nine distinct locations in the carrier. Eight revertant substitutions were isolated from the R52S strain: Asp-19→Gly, Asp-55→Asn, Pro-60→Gln, Trp-116→Arg, Asn-244→Ser, Ser-247→Arg, Asn-248→Lys, and Ile-352→Val. Two revertants were also isolated from the R52V strain: Trp-116→Arg and Thr-338→Arg revertants. The R52Q strain yielded an Asp-55→Asn substitution and a first-site revertant, Lys-52 (R52K). The R52K strain had transport properties similar to those of the wild type. Analysis of melibiose accumulation showed that proton-driven accumulation was still defective in the second-site revertant strains, and only the Trp-116→Arg, Ser-247→Arg, and Asn-248→Lys revertants regained significant Na
+
-coupled accumulation. In general, downhill melibiose transport in the presence of Na
+
was better in the revertant strains than in the parental mutants. Three revertant strains, Asp-19→Gly, Asp-55→Asn, and Thr-338→Arg strains, required a high Na
+
concentration (100 mM) for maximal activity. Kinetic measurements showed that the N248K and W116R revertants lowered the

K
m

for melibiose, while other revertants restored transport velocity. We suggest that the insertion of positive charges on membrane helices is compensating for the loss of Arg-52 and that helix II is close to helix IV and VII. We also suggest that Arg-52 is salt bridged to Asp-55 (helix II) and Asp-19 (helix I).
The
Archaeoglobus fulgidus
d
-Lactate Dehydrogenase Is a Zn
2+
Flavoprotein
Authors: Reed David W. , Hartzell Patricia L.
Published: December 2019

Archaeoglobus fulgidus
, a hyperthermophilic, archaeal sulfate reducer, is one of the few organisms that can utilize
d
-lactate as a sole source for both carbon and electrons. The
A. fulgidus
open reading frame, AF0394, which is predicted to encode a
d
-(−)-lactate dehydrogenase (Dld), was cloned, and its product was expressed in
Escherichia coli
as a fusion with the maltose binding protein (MBP). The 90-kDa MBP-Dld fusion protein was more efficiently expressed in
E. coli
when coexpressed with the
E. coli dnaY
gene, encoding the arginyl tRNA for the codons AGA and AGG. When cleaved from the fusion protein by treatment with factor Xa, the recombinant Dld (rDld) has an apparent molecular mass of 50 kDa, similar to that of the native
A. fulgidus
Dld enzyme. Both the purified MBP-Dld fusion protein and its rDld cleavage fragment have lactate dehydrogenase activities specific for
d
-lactate, are stable at 80°C, and retain activity after exposure to oxygen. The flavin cofactor FAD, which binds rDld apoprotein with a 1:1 stoichiometry, is essential for activity.
sn
-Glycerol-1-Phosphate-Forming Activities in
Archaea
: Separation of Archaeal Phospholipid Biosynthesis and Glycerol Catabolism by Glycerophosphate Enantiomers
Authors: Nishihara Masateru , Yamazaki Tomoko , Oshima Tairo , Koga Yosuke
Published: December 2019

In
Methanobacterium thermoautotrophicum
,
sn
-glycerol-1-phosphate (G-1-P) dehydrogenase is responsible for the formation of the
Archaea
-specific backbone of phospholipids, G-1-P, from dihydroxyacetonephosphate (DHAP). The possible G-1-P-forming activities were surveyed in cell-free extracts of six species of
Archaea
. All the archaeal cell-free homogenates tested revealed the ability to form G-1-P from DHAP. In addition, activities of G-3-P-forming glycerol kinase and G-3-P dehydrogenase were also detected in four heterotrophic archaea, while glycerol kinase activity was not detected in two autotrophic methanogens. These results show that G-1-P is produced from DHAP by G-1-P dehydrogenase in a wide variety of archaea while exogenous glycerol is catabolized via G-3-P.
Conserved Organization in the
cps
Gene Clusters for Expression of
Escherichia coli
Group 1 K Antigens: Relationship to the Colanic Acid Biosynthesis Locus and the
cps
Genes from
Klebsiella pneumoniae
Authors: Rahn Andrea , Drummelsmith Jolyne , Whitfield Chris
Published: December 2019

Group 1 capsules of
Escherichia coli
are similar to the capsules produced by strains of
Klebsiella
spp. in terms of structure, genetics, and patterns of expression. The striking similarities between the capsules of these organisms prompted a more detailed investigation of the
cps
loci encoding group 1 capsule synthesis. Six strains of
K. pneumoniae
and 12 strains of
E. coli
were examined. PCR analysis showed that the clusters in these strains are conserved in their chromosomal locations. A highly conserved block of four genes,
orfX-wza-wzb-wzc
, was identified in all of the strains. The
wza
and
wzc
genes are required for translocation and surface assembly of
E. coli
K30 antigen. The conservation of these genes points to a common pathway for capsule translocation. A characteristic JUMPstart sequence was identified upstream of each cluster which may function in conjunction with RfaH to inhibit transcriptional termination at a stem-loop structure found immediately downstream of the “translocation-surface assembly” region of the cluster. Interestingly, the sequence upstream of the
cps
clusters in five
E. coli
strains and one
Klebsiella
strain indicated the presence of IS elements. We propose that the IS elements were responsible for the transfer of the
cps
locus between organisms and that they may continue to mediate recombination between strains.
ANTIBODIES AGAINSTSTAPHYLOCOCCUS AUREUSIN NONIMMUNIZED RABBITS
Authors: Cohen Jay O. , Cowart Glenda S. , Cherry William B.
Published: January 2020

Cohen, JayO. (Communicable Disease Center, Atlanta, Ga.),Glenda S. Cowart, and William B. Cherry. Antibodies againstStaphylococcus aureusin nonimmunized rabbits. J. Bacteriol.82:110–114. 1961.—Antibody against staphylococci was demonstrated in the serum of each of 36 nonimmunized specific-pathogen-free rabbits that were tested. Evidence obtained is in agreement with the proposition that two distinct staphylococcal antibodies are present in the sera from these nonimmunized rabbits. One is responsible for agglutination ofStaphylococcus aureusCowan serotype I, and the other for the formation of a reaction line observed in Ouchterlony plates with soluble antigens of both Cowan serotype I and Cowan serotype III.

Fluorescent antibody reagent prepared from preimmune rabbit serum stained some strains of coagulase positive staphylococci, including Cowan's types I and III, and failed to stain any of 14 coagulase negative strains.

The sera of rabbits obtained from a commercial source were shown to contain other antibodies for staphylococci in addition to the two found in the sera of specific-pathogen-free rabbits. The data suggested that rabbits from commercial sources have had contact with a great variety of antigens capable of stimulating staphylococcal antibody.

Evidence demonstrated that normal rabbit serum from specific-pathogen-free animals of our colony could be used for differentiation of certain staphylococcal strains.
EFFECT OF VACCINES PREPARED FROMHISTOPLASMA CAPSULATUMAND OTHER YEASTS ON EXPERIMENTAL TUBERCULOSIS
Authors: Hedgecock Loyd W.
Published: January 2020

Hedgecock, LoydW. (Veterans Administration Hospital, Kansas City, Mo.). Effect of vaccines prepared fromHistoplasma capsulatumand other yeasts on experimental tuberculosis. J. Bacteriol.82:115–123. 1961.—Resistance to experimental tuberculosis was enhanced by the injection of a nonviable vaccine prepared fromHistoplasma capsulatumin the mycelial phase but not by the organism in the yeast phase. Acquired resistance was established within 7 days or less and usually maintained for at least 29 days. When both mycelium vaccine ofH. capsulatumand a vaccine prepared from tubercle bacilli were utilized in vaccination, the results were additive (in terms of acquired resistance) provided that an interval of 3 weeks was maintained between injection of each of the vaccines.

Resistance to tuberculosis was also demonstrable 14 days after the injection of nonviable preparations ofBrucella abortusandCryptococcus neoformans, as well as by yeast and mycelial vaccines ofBlastomyces dermatitidisandSporotrichum schenckii. Resistance decreased significantly when the animals were challenged 29 days after vaccination, with the exception of those injected with the yeast phase ofB. dermatitidis.
CORRELATION BETWEEN ACID PHOSPHATASE AND COAGULASE PRODUCTION OR PHAGE TYPE OFSTAPHYLOCOCCUS AUREUS
Authors: Pan Yue-Liang , Blumenthal Harold J.
Published: January 2020

Pan, Yue-Liang(University of Michigan Medical School, Ann Arbor),and Harold J. Blumenthal. Correlation between acid phosphatase and coagulase production or phage type ofStaphylococcus aureus. J. Bacteriol.82:124–129. 1961.—A quantitative assay of acid phosphatase in 26 coagulase-negative and 73 coagulase-positive strains ofStaphylococcus aureuswas performed using an assay procedure modified to estimate extracellular, as well as the cellular, phosphatase. Some of the factors affecting the formation of acid phosphatase were studied. On the average, coagulase-negative strains produced 4.0 units and coagulase-positive strains 19.6 units although some negative strains produced more phosphatase than positive strains. More phosphatase was produced by strains of phage-group I than by strains of any other group.
ISOLATION AND PRELIMINARY CHARACTERIZATION OF BACTERIOPHAGES FOR
BACILLUS SUBTILIS
Authors: Romig W. R. , Brodetsky A. M.
Published: January 2020

Romig
, W. R. (University of California, Los Angeles),
and A. M. Brodetsky
. Isolation and preliminary characterization of bacteriophages for
Bacillus subtilis
. J. Bacteriol.
82:
135–141. 1961.—A simplified procedure for direct isolation of phages for
Bacillus subtilis
from soil was developed. Phage enrichment was accomplished by growing streptomycin-resistant
B. subtilis
in medium previously inoculated with the soil sample. Contaminating soil bacteria were eliminated by adding bactericidal quantities of streptomycin and the phages were isolated by conventional agar layer techniques. By this method 1 or more subtilis phages were isolated from 15 of 18 soil samples tested. Several of these phages were unusually sensitive to chloroform and all of them were relatively unstable when stored at refrigerator temperatures. Of 6 phages retained for study, 1 was temperate for
B. subtilis
, but attempts to obtain stably lysogenic bacteria following infection with this phage were unsuccessful. All 6 phages had identical host ranges and were able to lyse all strains of
B. subtilis
tested, as well as several related species of
Bacillus
.
THIAMINE AND NICOTINIC ACID: ANAEROBIC GROWTH FACTORS FOR
MUCOR ROUXII
Authors: Bartnicki-Garcia S. , Nickerson Walter J.
Published: January 2020

Bartnicki-Garcia
, S. (Rutgers, the State University, New Brunswick, N. J.),
and Walter J. Nickerson
. Thiamine and nicotinic acid: Anaerobic growth factors for
Mucor rouxii
. J. Bacteriol. 82:142–148. 1961.—
Mucor rouxii
requires preformed thiamine and nicotinic acid for anaerobic growth. Such requirements are not manifested during aerobic incubation. Aerobically, the fungus was shown to be able to synthesize both vitamins.

The yeastlike form and the filamentous form of anaerobically grown
M. rouxii
exhibit the same vitamin requirements.

Thiamine can be substituted by its thiazole moiety. Under certain conditions, nicotinic acid was partly substituted by tryptophan, kynurenine, 3-hydroxykynurenine, and 3-hydroxyanthranilic acid.

Anaerobically. the fungus (thiamine requiring) was about ten times more susceptible to pyrithiamine antagonism than the same organism grown aerobically (thiamine independent).
SEROLOGICAL GROUPING OF ACTINOMYCES BY MEANS OF FLUORESCENT ANTIBODIES
Authors: Slack John M. , Winger Ann , Moore Dane W.
Published: January 2020

Slack, JohnM. (West Virginia University, Morgantown),Ann Winger, and Dane W. Moore, Jr.Serological grouping of actinomyces by means of fluorescent antibodies. J. Bacteriol.82:54–65. 1961.—Serological groups A, B, C and D of actinomyces were established using fluorescent antibody techniques. One hundred and thirty-eight cultures were included in the study. Eighty-nine were classed in group A, 15 in B, 13 in C, and 21 in D.

The isolates were from patients and animals with actinomycosis and from healthy human beings. There was no correlation between source of the isolate and serological group. Furthermore, no one species could be placed exclusively in one group although the majority of those designated asActinomyces boviswere in group A.

Seventeen anaerobic diphtheroids and sevenCorynebacterium acnesisolates were placed in group A. One diphtheroid was in each of groups B and D. On this basis it is suggested that these organisms be included in the genusActinomyces.

Additional species ofCorynebacteriumas well asLactobacillus Propionibacterium, Streptomyces, andNocardiadid not fluoresce with any of the group antisera.
RELATIONSHIPS BETWEEN INITIAL NUTRIENT CONCENTRATION AND TOTAL GROWTH
Authors: Ecker R. E. , Lockhart W. R.
Published: January 2020

Ecker
, R. E. (Iowa State University, Ames),
and W. R. Lockhart
. Relationships between initial nutrient concentration and total growth. J. Bacteriol.
82:
80–84. 1961.—The relationship observed between maximal attainable growth in a microbial population and initial concentration of limiting nutrient depends upon the parameter selected for measurement of growth. A linear relationship is found only when cell mass is the parameter. When population is used as the measure of growth, the relationship is:
N
max
=
K′C
0

s

, where
N
max
is the maximal attainable population,
C
0
is the initial concentration of limiting nutrient and
K′
and
s
are constants. The use of this expression in demonstrating subtle differences between strains is shown.
NUTRITION OFSTREPTOCOCCUS BOVISIN RELATION TO DEXTRAN FORMATION
Authors: Barnes Isabel J. , Seeley H. W. , VanDemark P. J.
Published: January 2020

Barnes, IsabelJ. (Cornell University, Ithaca, N. Y.), H. W.Seeley, and P. J. VanDeMark. Nutrition ofStreptococcus bovisin relation to dextran formation. J. Bacteriol.82:85–93. 1961.—Three nutritional types ofStreptococcus boviswere encountered. Minimal media for their growth are described. Transferable growth in defined media was always accompanied by dextran production and the nutrition for dextran production could not be distinguished from the minimal nutritional requirements of the organism for growth. Measurable, free CO2was evolved from a complex medium during the growth ofS. bovis. Several compounds were found to replace partially the CO2requirement of the species. When fractured cell preparations containingS. bovisdextran were employed as antigens, rabbits failed to yield sera which would precipitateS. bovisor leuconostoc dextrans.
MECHANISM OF CHEMICAL MUTAGENESIS IV
Authors: Lorkiewicz Z. , Szybalski Waclaw
Published: January 2020

Lorkiewicz
, Z. (University of Wisconsin, Madison),
and Waclaw Szybalski
. Mechanism of chemical mutagenesis. IV. Reaction between triethylene melamine and nucleic acid components. J. Bacteriol.
82:
195–201. 1961.—Triethylene melamine interacts primarily with phosphorylated intracellular deoxyribonucleic acid (DNA) precursors and not with DNA. It was found by direct chemical and chromatographic analysis that only pyrimidine precursors of nucleic acids are attacked by triethylene melamine. In the course of the triethylene melamine-deoxycytidine reaction the mutagenicity of the reaction mixture is lost, but the mutagenicity of the triethylene melamine-thymidine reaction products significantly increases above that of the reaction substrates. Several steps are postulated to explain the mechanism of the triethylene melamine-initiated mutagenic reaction: (i) Reaction I, semireversible uptake of triethylene melamine; (ii) reaction II, chemical interaction between triethylene melamine and intracellular thymidine mono- or triphosphate with the production of a functional analogue of the latter; (iii) incorporation of this fraudulent analogue into the newly formed DNA strand; (iv) occurrence of self-perpetuating errors in the sequence of natural bases during subsequent rounds of replication of the analogue-containing DNA strand. It is postulated that the mechanism of mutagenic responses to different types of mutagens can fit either a simplified (mutagenic base analogues) or extended version (radiation) of this schema.
ACETATE FORMATION IN
CLOSTRIDIUM ACIDI-URICI
: ACETOKINASE
Authors: Sagers Richard D. , Benziman Moshe , Gunsalus I. C.
Published: January 2020

Sagers, Richard
D. (University of Illinois, Urbana),
Moshe Benziman, and I. C. Gunsalus
. Acetate formation in
Clostridium acidiurici:
Acetokinase. J. Bacteriol.
82:
233–238. 1961.—To define the energy-yielding reaction(s) during fermentation of purines by
Clostridium acidi-urici
, an eightfold purified acetokinase was obtained by protamine and ammonium sulfate fractionation of crude extracts. Enzyme activity was determined by measuring the disappearance of acetyl phosphate using adenosine diphosphate (ADP) as phosphate acceptor or by following the generation of acetyl phosphate from adenosine triphosphate (ATP) + acetate. The optimal pH for the reaction was observed to be 7.4.

K
m

values for acetyl phosphate, ADP, and magnesium ions were shown to be 2.1 × 10
−3
m
, 3.2 × 10
−3
m
, and 2.4 × 10
−3
m
, respectively. Acetyl phosphate disappearance is dependent upon ADP and is stoichiometric with addition of the latter. The acetokinase reaction probably represents the major energy-yielding reaction during purine fermentation by this organism. A pathway for acetate generation from formiminoglycine is proposed, and evidence for a number of enzyme activities intermediate between formiminoglycine degradation and acetate formation is given. The enzyme activities demonstrated are compatible with the over-all purine fermentation rate by whole cells.
DIFFERENTIATION OF BRUCELLAE BY THE AID OF PHAGES
Authors: Parnas Józef
Published: January 2020

Parnas, Józef
(Academy of Medicine, Lublin, Poland). Differentiation of brucellae by the aid of phages. J. Bacteriol.
82:
319–325. 1961.—There appears to be no absolute specificity of phages for the three species of the genus
Brucella
. The phage test is only supplementary to biochemical and serological methods for species differentiation.
BEHAVIOR OF BACTERIAL SPORES IN AQUEOUS POLYMER TWO-PHASE SYSTEMS
Authors: Sacks L. E. , Alderton Gordon
Published: January 2020

Sacks
, L. E. (Western Regional Research Laboratory, Albany, California),
and Gordon Alderton
. Behavior of bacterial spores in aqueous polymer two-phase systems. J. Bacteriol.
82:
331–341. 1961.—Free spores of various species of the
Bacillaceae
enter the upper phase in a two-phase aqueous polymer system containing polyethylene glycol 4000 and potassium phosphate. Vegetative cells appear in the lower phase and subcellular debris is concentrated chiefly at the interface. The high selectivity of the upper phase for spores makes possible the preparation of greatly enriched concentrates of spores directly from complex natural materials, such as soil and feces. Attraction of spores for the upper phase is not diminished by autoclaving and the release of dipicolinic acid. Loss of attraction of spores for the upper phase is associated in time with the shedding of the spore coat, upon outgrowth. The partition behavior of one preparation of
Bacillus megaterium
showed the presence of two classes of spores.
ACTION OF PENICILLIN ON
AEROBACTER CLOACAE
Authors: Hugo W. B. , Russell A. D.
Published: January 2020

Hugo
, W. B. (University of Nottingham, Nottingham, England),
and A. D. Russell
. Action of penicillin on
Aerobacter cloacae
. J. Bacteriol.
82:
411–417. 1961.—A study has been made of the action of penicillin on a penicillinase-producing strain of
Aerobacter cloacae
. It has been found that in culture media rendered hypertonic by the addition of sucrose (0.33 to 0.66
m
), provided a source of magnesium ions is present, cell wall lesions occur, giving rise to osmotically fragile spheroplasts. Evidence is also presented of a lethal effect not associated with cell wall damage. Penicillinase production is not a complete challenge to the action of penicillin and in certain experimental situations renders the cells more susceptible to penicillin action.
NONSAPONIFIABLE LIPIDS OF REPRESENTATIVE PLEUROPNEUMONIA-LIKE ORGANISMS
Authors: Rothblat George H. , Smith Paul F.
Published: January 2020

Rothblat, George
H. (University of Pennsylvania, Philadelphia),
and Paul F. Smith
. Nonsaponifiable lipids of representative pleuropneumonia-like organisms. J. Bacteriol.
82:
479–491. 1961.—The fate of cholesterol and the nature of carotenoid pigments in various strains of pleuropneumonia-like organisms have been determined by characterization of their nonsaponifiable lipids. All of the cholesterol removed from the medium by a nonfermentative sterol-requiring strain remains unchanged except for a portion of it being esterified. A fermentative sterol-requiring strain of avian origin converts part of the cholesterol to cholesteryl-β-
d
-glucoside, the amount in the glucoside form being governed by the amount of glucose supplied in the growth medium. This cholesteryl-β-
d
-glucoside was found to be formed by a fermentative, nonsterol-requiring strain only when supplied exogenous cholesterol. No cholesterol or its derivatives were found in nonsterol-requiring strains when grown in the absence of cholesterol. Three carotenoid pigments were isolated from nonsterol-requiring strains. The most nonpolar pigment was identified as neurosporene. The second pigment appearing in chromatographic column eluates appears to be a hydroxylated neurosporene, based on its polarity and absorption spectrum. The most polar pigment was found to contain reducing sugar following acid hydrolysis and appears to be a carotenoid-glucose complex. When the nonsterol-requiring strains are grown in the presence of cholesterol, cholesterol partially supplants the role of carotenoids and decreases the amount of carotenoids synthesized. The role of steroids and carotenoids in these organisms is discussed.
ANTIGENIC STUDIES OF CANDIDA
Authors: Hasenclever H. F. , Mitchell William O.
Published: January 2020

Hasenclever
, H. F. (U. S. Public Health Service, Bethesda, Md.),
and William O. Mitchell
. Antigenic studies of Candida. I. Observations of two antigenic groups in
Candida albicans
. J. Bacteriol.
82:
570–573. 1961.—Two distinct antigenic groups, detected by tube agglutination, have been observed among strains of
Candida albicans
. Adsorption of an antiserum with a heterologous strain did not remove the agglutinating properties for the homologous strain. Homologous adsorption of the antiserum did remove its agglutinating properties. Seventy-one isolates of
C. albicans
have been screened with this adsorbed antiserum and 38 were agglutinated at a serum dilution of 1:240 to 1:480 (group A), whereas 33 were not agglutinated at a serum dilution of 1:30 (group B). Thirty-five of the strains were studied with rabbit antisera prepared against each of six strains (three from each group). Agglutination reactions of these strains with samples of each antiserum adsorbed individually with each immunizing strain verified the results of the screening agglutination reactions. All the agglutinating properties of antisera prepared against the three group B strains were removed by adsorption with suspensions of either group A or group B strains. The identity of all isolates used in this study was confirmed by chlamydospore formation, fermentation, and carbohydrate assimilation reactions.
MANIFESTATIONS OF INJURY IN YEAST CELLS EXPOSED TO SUBZERO TEMPERATURES I
Authors: Mazur Peter
Published: January 2020

Mazur, Peter
(Oak Ridge National Laboratory, Oak Ridge, Tenn.). Manifestations of injury in yeast cells exposed to subzero temperatures. I. Morphological changes in freeze-substituted and in “frozen-thawed” cells. J. Bacteriol.
82:
662–672. 1961.—When cells of the yeast
Saccharomyces cerevisiae
are cooled rapidly to −30 C or below, fewer than 0.01% survive. In contrast, when they are cooled slowly, up to 50% survive. The effect of cooling rate on survival was reflected in the morphological appearance of cells both before and after thawing. Appearance before thawing was observed by fixing the cells at subzero temperatures by freeze-substitution with cold ethanol. Slowly cooled freeze-substituted cells were considerably smaller and more flattened than those cooled rapidly. The differences in appearance and the differences in survival are both consistent with the view that intracellular ice formation occurs more extensively in rapidly cooled cells and is responsible for their higher mortality.

In spite of the high mortality (more than 99.99% killed), rapidly cooled cells remained as intact morphological entities when they were allowed to warm and thaw instead of undergoing freeze-substitution. However, they did differ from normal living yeast in two major respects: Their volume was halved and they lacked the large vacuole found in almost all the untreated living cells. The possession of a vacuole was closely correlated with survival. Suspensions warmed after slow cooling to −30 C contained cells of normal appearance and also nonvacuolate smaller ones. The admixture of morphological types was consistent with the fact that slow cooling yielded a higher percentage of viable cells than did rapid cooling.
EFFECTS OF SOME MECHANICAL FACTORS ON THE ENDOSPORES OF
BACILLUS SUBTILIS
Authors: Knaysi Georges , Curran Harold R.
Published: January 2020

Knaysi, Georges
(Cornell University, Ithaca, N. Y.)
and Harold R. Curran
. Effects of some mechanical factors on the endospores of
Bacillus subtilis
. J. Bacteriol.
82:
691–694. 1961.—Phase contrast microscopy was used to study incipient spore germination and early growth under conditions involving agitation with a platinum wire loop, sonic oscillation, and freezing and thawing. Treatment resulted in change in optical properties and destruction of a certain proportion of the spores. Up to one-tenth of the spores was destroyed by loop agitation. Sonic oscillation had little apparent effect upon incipient germination (darkening) of the spores, but subsequent development involving growth was stimulated in a considerable proportion. The effect of freezing and thawing upon incipient germination is discussed.
UTILIZATION OF SULFUR COMPOUNDS BY
STREPTOCOCCUS BOVIS
Authors: Prescott J. M.
Published: January 2020

Prescott
, J. M. (A. &. M. College of Texas, College Station). Utilization of sulfur compounds by
Streptococcus bovis
. J. Bacteriol.
82:
724–728. 1961.—Two strains of
Streptococcus bovis
utilize a variety of compounds as their only source of sulfur, yet exert a definite selectivity in their nutritional requirements for this element. Among sulfur-containing amino acids and related compounds, cystine and cysteine support excellent growth, but cysteic acid and cysteine sulfinic acid do not; methionine is completely inactive as an only sulfur source, but growth is provided by lanthionine, djenkolic acid,
allo
-cystathionine, homocystine, homocysteine, and glutathione. Several organic sulfur compounds other than amino acids are effective sulfur sources, among which are thioglycolate, thiomalate, thiourea, and thiouracil. In contrast, thiodiglycolate, thiodiglycol, and (phenylthio) acetic acid fail to support growth. Of the inorganic sulfur sources tested, sulfide and thiosulfate are utilized, but sulfite and sulfate are not; it thus appears that the state of oxidation is a critical factor in the utilization of sulfur by these strains of
S. bovis
. A complex amino acid mixture, without sulfur-containing amino acids, produces more rapid and reproducible growth than either arginine or ammonium acetate when used as a nitrogen source for testing the sulfur compounds. Growth rates are frequently better when the sulfur sources are autoclaved than when they are sterilized by filtration, although the qualitative responses to the compounds are generally similar.
EFFECT OF AMMONIUM ION ON GROWTH AND METABOLISM OF
MICROCOCCUS SODONENSIS
Authors: Campbell J. N. , Evans James B. , Perry Jerome J. , Niven C. F.
Published: January 2020

Campbell
, J. N. (American Meat Institute Foundation, Chicago, Ill.),
James B. Evans, Jerome J. Perry, and C. F. Niven, Jr.
Effect of ammonium ion on growth and metabolism of
Micrococcus sodonensis
. J. Bacteriol.
82:
823–827. 1961.—When
Micrococcus sodonensis
was grown in a synthetic medium deficient in ammonia, large quantities of α-keto acids, chiefly α-ketoglutaric, accumulated in the medium. The addition of ammonium chloride to this medium prevented such accumulation and also supported increased growth, even in the presence of excess glutamate. Neither potassium nor sodium would substitute for ammonia in producing this effect.

The results indicate that this microorganism has a specific requirement for the ammonium ion in its growth and metabolism. If not supplied exogenously, ammonia is made available by deamination of glutamic acid. The exact route of incorporation of ammonia is unknown.
ROLE OF CITRITASE IN ACETOIN FORMATION BY
STREPTOCOCCUS DIACETILACTIS
AND
LEUCONOSTOC CITROVORUM
Authors: Harvey R. J. , Collins E. B.
Published: January 2020

Harvey
, R. J. (University of California, Davis)
and E. B. Collins
. Role of citritase in acetoin formation by
Streptococcus diacetilactis
and
Leuconostoc citrovorum
. J. Bacteriol.
82:
954–959. 1961.—Cell-free extracts of
Streptococcus diacetilactis
and
Leuconostoc citrovorum
converted citrate to acetate, oxalacetate, pyruvate, carbon dioxide, and acetoin. The products, stoichiometry, and cofactor requirements of the citrate-splitting reaction were identical to those reported for citritase. Coenzyme A was not required; the reaction was stimulated by magnesium or manganous ions, and inhibited by calcium ions. In
S. diacetilactis
the enzyme is constitutive; it has been found inducible in all other organisms that have been studied. Ten strains of
S. diacetilactis
, three strains of
Leuconostoc
, and one strain of
S. liquefaciens
contained the enzyme; 21 strains of
S. cremoris
and 3 strains of
S. lactis
did not. Cell-free extracts of
S. diacetilactis
and
L. citrovorum
converted pyruvate to acetoin and carbon dioxide in the presence of manganous ions and thiamine pyrophosphate.
COMPARISON OF GROWTH AND PECTOLYTIC ENZYME PRODUCTION BY
BACILLUS POLYMYXA
Authors: Nagel Charles W. , Vaughn Reese H.
Published: January 2020

Nagel, Charles W.
(University of California, Davis)
and Reese H. Vaughn
. Comparison of growth and pectolytic enzyme production by
Bacillus polymyxa
. J. Bacteriol.
83:
1–5. 1962.—Studies were made of pectolytic enzyme production by
Bacillus polymyxa
during growth. It was found that elaboration of enzyme occurred during logarithmic growth and ceased when the stationary phase was reached. The specific activity of the extra-cellular enzyme remained relatively constant until lysis occurred. The increased specific activity of the intracellular pectolytic enzyme may be explained if one assumes that the rate of secretion of the intracellular enzyme is dependent upon the concentration of the extracellular enzyme. The concentration of the intracellular pectolytic enzyme dropped markedly at the end of the logarithmic growth phase; the enzyme was released into the medium during the stationary growth phase and subsequent lysis of the cells. It was shown that the intra- and extracellular enzymes were similar or identical in that both were calcium-dependent pectic acid transeliminases.
EFFECT OF THE ANTIBACTERIAL SERUM FACTOR ON STAPHYLOCOCCAL INFECTIONS
Authors: Yotis William W.
Published: January 2020

Yotis, W. W.
(Loyola University Medical School, Chicago, Ill.). Effect of the antibacterial serum factor on staphylococcal infections. J. Bacteriol.
83:
137–143. 1962—Intracerebral injections of mice with 1 to 5 × 10
6
washed viable cells previously exposed for 1 hr at 4 C to 2 mg/ml of the serum factor resulted in 0 to 30% mortality when three recent isolates of yellow, hemolytic, coagulase-positive strains of
Staphylococcus aureus
were used. Mice inoculated in the same manner with the above strains, but exposed to an inactive preparation of the serum factor, showed a 60 to 90% mortality.

Addition of partially purified coagulase to the serum factor neutralized the protective action of the serum factor.

The serum factor was found primarily in the supernatant obtained following 62% (NH
4
)
2
SO
4
saturation of the water-soluble globulin portion and precipitated by one-half volume of undiluted 95% ethanol. Plate counts, manometric techniques, and animal protection studies were employed to follow purification of the serum factor. If dry weight is taken as the criterion of purification, the active substance showed a 40-fold purification over a previous preparation of this substance.
ACTION OF CYCLOHEXIMIDE ON
ZYGOSACCHAROMYCES SOJA
Authors: Tsukada Yoji , Sugimori Tsunetake , Imai Kazutami , Katagiri Hideo
Published: January 2020

Tsukada, Yoji
(Kyoto University, Kyoto, Japan),
Tsunetake Sugimori, Kazutami Imai, and Hideo Katagiri
. Action of cycloheximide on
Zygosaccharomyces soja
. J. Bacteriol.
83:
70–75. 1962.—Cycloheximide is known to inhibit the growth of some species of
Saccharomyces
and other fungi. A new type of action of this antibiotic, with
Zygosaccharomyces soja
as the test organism, is described in this paper. Growth of
Z. soja
was completely inhibited under aerobic conditions by cycloheximide in concentrations of more than 5 μg per ml of culture solution. Continued shaking of the culture for more than 96 hr in the presence of an inhibitory amount of cycloheximide restored growth, accompanied by the excretion of riboflavin to the extent of 30 μg per ml of culture solution. In the cells recovering from cycloheximide inhibition, the type of glucose metabolism differed from that in the mother strain; a respiratory quotient of 4 with the mother strain fell to 1 in the progeny. Glucose metabolism (O
2
uptake and CO
2
evolution) by resting cells was investigated, and it was concluded that inhibition of glycolysis was not significant. This was verified by comparing various dehydrogenase activities in the cell-free extract. There were essentially no differences between riboflavin-forming and nonriboflavin-forming cells. The presence of the hexose monophosphate shunt was deduced from the fact that glucose-6-phosphate dehydrogenase activity was the strongest of the various dehydrogenase activities.
INCREASED RESISTANCE TO CHLORAMPHENICOL IN
RICKETTSIA PROWAZEKII
WITH A NOTE ON FAILURE TO DEMONSTRATE GENETIC INTERACTION AMONG STRAINS
Authors: Weiss Emilio , Dressler Harry R.
Published: January 2020

Weiss, Emilio
(Naval Medical Research Institute, Bethesda, Md.)
and Harry R. Dressler
. Increased resistance to chloramphenicol in
Rickettsia prowazekii
with a note on failure to demonstrate genetic interaction among strains. J. Bacteriol.
83:
409–414. 1962.—A further effort to produce genetically labeled
Rickettsia prowazekii
was made by serially passing the Madrid E strain in eggs in the presence of increasing concentrations of chloramphenicol. After 40 serial and 1 limit-dilution passages, a substrain, called C
r
, was isolated, which appeared to be the result of a two-step change, each involving a twofold increase in resistance to the antibiotic. Chloramphenicol resistance was retained after 10 drugless egg passages. Cross-resistance to thiocymetin, but not to unrelated drugs, was shown.

Several attempts were made to demonstrate genetic interaction, in eggs or entodermal cell cultures, among strains resistant to chloramphenicol, erythromycin, and
p
-aminobenzoic acid. They have not been successful.
TEMPERATURE-GRADIENT PLATES FOR GROWTH OF MICROORGANISMS
Authors: Landman Otto E. , Bausum Howard T. , Matney Thomas S.
Published: January 2020

Landman, Otto
E. (Fort Detrick, Frederick, Md.),
Howard T. Bausum, and Thomas S. Matney
. Temperature-gradient plates for growth of microorganisms. J. Bacteriol.
83:
463–469. 1962.—Different temperature-gradient plates have been devised for the study of microbial growth on solid media through continuous temperature ranges or in liquid media at finely graded temperatures. All plates are made of heavy-gauge aluminum; heat supplied at one end is dissipated along the length of the metal so that a gradient is produced. The shape and range of the gradient depends on the amount of heat supplied, the insulation, the ambient temperature, and other factors. Differences of 0.2 C in temperature sensitivity between bacterial strains can be detected. The plates are simple to construct and operate. The dimensions of the aluminum, the mode of temperature measurement, and the method of heating may all be modified without diminishing the basic utility of the device.

A sharp growth front develops at the maximal temperature of growth of bacteria. In most strains, all bacteria below the front form colonies and all bacteria above the front are killed, except for a few temperature-resistant mutants.
ACCUMULATION OF S-ADENOSYLMETHIONINE BY MICROORGANISMS
Authors: Gawel L. J. , Turner J. R. , Parks L. W.
Published: January 2020

Gawel
, L. J. (Oregon State University, Corvallis), J. R.
Turner, and L. W. Parks
. Accumulation of S-adenosylmethionine by microorganisms. J. Bacteriol.
83:
497–499. 1962.—A series of microorganisms selected to represent a variety of microbial types was cultured under conditions conducive to the formation of S-adenosylmethionine. Of the organisms tested, only
Saccharomyces cerevisiae
accumulated measurable amounts of S-adenosylmethionine.
Pseudomonas fluorescens
and
Escherichia coli
accumulate 5′-methylthioadenosine under the same conditions.
TRANSDUCTION OF THE ATTACHED SEX FACTOR OF
ESCHERICHIA COLI
Authors: DeWitt Susanne K. , Adelberg Edward A.
Published: January 2020

DeWitt, Susanne
K. (University of California, Berkeley)
and Edward A. Adelberg
. Transduction of the attached sex factor of
Escherichia coli
. J. Bacteriol.
83:
673–678. 1962.—The linkage of the sex factor to one extremity of the chromosome in Hfr cells of
Escherichia coli
has been confirmed by transduction experiments. In Hfr P4x-6,
lac
is the last marker to penetrate the female during conjugation. When
lac
+
was transduced from P4x-6 into a
lac
−
strain by phage Plkc, 5% cotransduction of the sex factor was observed. No cotransduction of the sex factor was observed when markers other than
lac
+
were selected.

The transduced males resembled the Hfr parent with respect to the site of attachment and orientation of the sex factor, the order of genetic markers transferred, and the gradient of recombination frequencies produced with a given female. When the
lac
−
recipient used in the transduction carried an
sfa
locus in a different region of the chromosome, the over-all rate of cotransduction was tenfold lower, but the transduced males again resembled the Hfr parent in their sexual behavior.
AEROBIC SPORULATING BACTERIA I
Authors: Bach John A. , Sadoff H. L.
Published: January 2020

Bach, John
A. (Michigan State University, East Lansing)
and H. L. Sadoff
. Aerobic sporulating bacteria. I. Glucose dehydrogenase of
Bacillus cereus
. J. Bacteriol.
83:
699–707. 1962.—A heat-resistant glucose dehydrogenase occurs in cultures of
Bacillus cereus
which are in the initial stages of sporulation. This enzyme is, kinetically, identical to the glucose dehydrogenase which can be extracted from mature spores, but is considerably more heat resistant than the spore-free enzyme. The two enzymes produce identity lines in two-dimensional immunodiffusion experiments, and their behavior in chromatographic and electrophoretic studies is also identical.

A labile glucose dehydrogenase can be extracted from germinated spores of
B. cereus
. It differs from its stable counterparts in possessing a higher pH optimum for enzymatic activity.
FERMENTATION REACTIONS OF
PSEUDOMONAS CAVIAE
AND ITS SEROLOGICAL RELATIONSHIP TO AEROMONADS
Authors: Liu Pinghui V.
Published: January 2020

Liu, Pinghui
V. (University of Louisville School of Medicine, Louisville, Ky.). Fermentation reactions of
Pseudomonas caviae
and its serological relationship to aeromonads. J. Bacteriol.
83:
750–753. 1962.—
Pseudomonas caviae
was found to ferment carbohydrates instead of oxidizing them. This characteristic would seem to eliminate this organism from the genus
Pseudomonas
and place it in the genus
Aeromonas
. It was identified as
A. liquefaciens
, by its species-specific extracellular antigens and by neutralization of its enzyme.