bluuebunny/crossref_metadata_2025 huggingface dataset:
Biochemical Alternations in
Bacillus megaterium
as Produced by Aflatoxin B
1
Authors: Beuchat L. R. , Lechowich R. V.
Published: December 2020

Bacillus megaterium
NRRL B-1368 cells and spores were produced on Trypticase Soy Broth (TSB) and Agar (TSA) containing 3.8 μg of aflatoxin B
1
per ml, analyzed for selected chemical constituents, and compared to cells and spores of
B. megaterium
produced on nontoxic Trypticase Soy Media. There was an initial 30% kill of cells after inoculation into toxic TSB and during the first 3.5 hr of incubation followed by a logarithmic growth phase in which the generation time was 75 min as compared to 20 min for the control culture. Chemical analyses revealed an increase in protein, deoxyribonucleic acid (DNA), and ribonucleic acid (RNA) on both a per cell basis and a per cent dry weight basis when
B. megaterium
was grown in toxic TSB. There was a concurrent decrease in the total amounts of cellular protein, DNA, and RNA synthesized in toxic TSB. Amino acid analyses of control and test cell walls showed little, if any, difference in cell wall composition. About 97% sporulation of
B. megaterium
occurred after 3 days on nontoxic TSA although 6 days were required to attain 65% sporulation on toxic TSA. Germination of spores was not inhibited by 4.0 μg of aflatoxin per ml but outgrowth was. No significant differences were observed in the heat resistance, protein, DNA, RNA, or dipicolinic acid content of spores formed on toxic TSA and nontoxic TSA.
Morphological Alterations in
Bacillus megaterium
as Produced by Aflatoxin B
1
Authors: Beuchat L. R. , Lechowich R. V.
Published: December 2020

Morphologically abnormal cells were produced by
Bacillus megaterium
NRRL B-1368 in response to aflatoxin B
1
. Filamentous forms were characterized by early granulation and unusually large and numerous deposits of poly-β-hydroxybutyric acid within the cells. Pantoyl lactone was without effect as a reversing agent for the observed inhibition of cell septum formation.
B. megaterium
cells and spores produced on toxic (3.8 μg of aflatoxin B
1
per ml) and nontoxic Trypticase Soy Broth and Trypticase Soy Agar (TSA) were observed by using phase contrast and electron microscopy. Transfer of aberrant forms to nontoxic TSA yielded macrocolonies with daughter cells morphologically indistinguishable from untreated cells. Agar slide cultures of filamentous cells transferred to nontoxic TSA indicated that normal cells were formed. Electron photomicrographs showed a decreased number of mesosomes in filamentous cells as compared to control cells. There were no observable morphological differences in spores formed on toxic or nontoxic TSA.
New Technique for Microscopic Examination of the Fouling Community of Submerged Opaque Surfaces
Authors: Sechler Gary E. , Gundersen K.
Published: December 2020

The fouling film formed on surfaces of opaque materials submerged in seawater could be almost quantitatively removed for microscopy by application of a Parlodion film.
Filamentous Fungi and Bacteria in Macaroni and Spaghetti Products
Authors: Christensen C. M. , Kennedy B. W.
Published: December 2020

Filamentous fungi, especially
Aspergillus flavus-oryzae
, and bacteria were present in all samples of macaroni and spaghetti products tested. No aflatoxin was detected in the three samples, all relatively high in
A. flavus-oryzae
, that were tested for it. Five of the nine isolates of
A. flavus-oryzae
from macaroni and sphaghetti grown in corn, incorporated into an otherwise balanced ration, and given to ducklings resulted in death of one to five ducklings within six days.
Preliminary Observations on the Rapid Differentiation of the
Klebsiella-Enterobacter-Serratia
Group on Bile-Esculin-Agar
Authors: Wasilauskas Benedict L.
Published: December 2020

A total of 232 isolates of
Enterobacteriaceae
and 19
Pseudomonas
species were tested on bile-esculin-agar. Only the
Klebsiella-Enterobacter-Serratia
group produced blackening of the medium.
Colicin Typing as an Epidemiological Tool in the Investigation of Outbreaks of
Shigella sonnei
Authors: Reller L. Barth
Published: December 2020

Shigella sonnei
has become the most frequently reported cause of shigellosis in the United States. Since
Shigella
subgroup D has no other serotypes, colicin production has been used as a basis for differentiating and identifying epidemiologically related strains. The results of colicin typing 115 cultures of
S. sonnei
from eight outbreaks of shigellosis occurring in widely separated regions of the United States support the usefulness of this technique. In each outbreak, the cultures were either of the same colicin type or were uniformly untypable. Unrelated cases yielded a variety of types. Definitions of the relative frequencies and geographic distributions of the various strains of
S. sonnei
in the United States await an accumulation of experience with the method.
Outer Cell Envelope Glycoprotein from Two Strains of
Serratia marcescens
Authors: Tsang Joseph C. , Tattrie Sandy , Kallvy Dennis
Published: December 2020

Cell envelope glycoproteins were extracted with sodium dodecyl sulfate from isolated cell walls of two strains of
Serratia marcescens
and purified by gel filtration column chromatography on Sepharose 4B. There was no significant difference in the chemical composition. Both fractions contained approximately 50% proteins and 10% carbohydrates. Glucosamine and glucose were identified as the only sugar components in the carbohydrate moiety. Immunochemically they shared at least one common antigenic component with each other and possibly with their corresponding lipopolysaccharide fractions.
Isolation of Shigellae
Authors: Taylor Welton I. , Schelhart Dorothy
Published: December 2020

Two enrichment broths and four plating media were compared for efficiency of detection of enteric pathogens from 1,597 stool specimens. Of 170 salmonellae isolated from the composite of all methods, direct streaking yielded but 54%, whereas enrichment in gram-negative broth found 87% and Selenite-F broth 97%. By contrast, gram-negative broth produced 100% of the 17 shigellae, Selenite-F broth but 77%, and direct streaking only 59%. Thus, enrichment methods produced almost twice the number of both pathogens as direct streaking. Comparison of the plating media revealed xylose lysine deoxycholate agar (XLD) and Hektoen enteric agar to be equal in their abilities to find both pathogens. Both were moderately better than Salmonella-Shigella agar and markedly superior to eosin methylene blue agar. XLD fround 83% of salmonellae produced by the composite of four media and 90% of the shigellae. Hektoen enteric agar found 80% of both. Salmonella-Shigella agar detected 74 and 68%, respectively, and eosin methylene blue agar only 42 and 63%. The numbers of false positives accruing to each medium, however, showed Hektoen enteric and Salmonella-Shigella agars to produce more than twice as many false-positive plates as XLD. Similarly, Selenite-F broth resulted in many more false-positives for all plating media than did gram-negative broth. Consequently, the index of validity, which equates successful isolation of pathogens with total pickings, favored XLD and gram-negative broth as the media of choice, with direct streaking the poorest method by all counts.
Antibacterial Action of Spermine: Effect on Urinary Tract Pathogens
Authors: Fair William R. , Wehner Nancy
Published: December 2020

The basic polyamine spermine was tested for antibacterial activity at two
p
H levels by the modified cup method against a variety of gram-positive and gram-negative organisms isolated from urine. At
p
H 6.4, with concentrations ranging from 39 to 2,500 μg per 0.1 ml, there were no clear zones of inhibition seen with any of the gram-negative test organisms, although some adverse effect on growth within the area of the cylinder was noted in 36%. Three of 17 gram-positive strains were inhibited at this
p
H. Spermine was more active at
p
H 7.4, but even at the highest concentrations only 16% of the gram-negative and 47% of the gram-positive bacteria tested showed definite zones of inhibition. It is concluded that spermine probably plays little, if any, role in natural resistance to urinary tract infections in vivo.
Semisynthetic Penicillin 6-[
d
(—)-α-Carboxy-3-Thienylacetamido] Penicillanic Acid Active Against
Pseudomonas
In Vitro
Authors: Neu H. C. , Winshell E. B.
Published: December 2020

The activity of 6-[
d
(—)-α-carboxy-3-thienylacetamido] penicillanic acid, BRL2288, was determined against
Pseudomonas aeruginosa
and various gram-negative bacilli. The majority of
Pseudomonas
strains (89%) were inhibited by 100 μg of the antibiotic per ml. BRL2288 is twofold more active than carbenicillin against
Pseudomonas
at 100 μg/ml or less. Among
Enterobacteriaceae
tested, 87%
Enterobacter
and 87% of
Proteus mirabilis
strains were inhibited by 25 μg/ml or less. Indole-positive
Proteus
were inhibited by 10 μg/ml or less. Fifty-five per cent of ampicillin-resistant
Escherichia coli
were inhibited by 100 μg/ml.
Klebsiella
were uniformly resistant. BRL2288 is not hydrolyzed by most resistant
Pseudomonas
, but it is destroyed by the β-lactamases of
E. coli
and
P. mirabilis.
The antibiotic shows synergy with gentamicin but not with penicillinase-resistant penicillins such as cloxacillin. Activity of BRL2288 against gram-positive organisms is two- to eightfold less than that of ampicillin or benzylpenicillin G.
Conditions for Production of 3-Ketomaltose from
Agrobacterium tumefaciens
Authors: Tyler D. D. , Nakamura L. K.
Published: December 2020

Up to 39% yields of 3-ketomaltose were achieved in 18 to 22 hr when
Agrobacterium tumefaciens
NRRL B-36 was cultured at 25 to 28 C in a simple medium containing 4.0 to 8.0% maltose, 0.09% urea, 0.5% CaCO
3
, 0.6% KH
2
PO
4
, and 0.025% MgSO
4
·7H
2
O. For maximum production of 3-ketomaltose the culture had to be maintained approximately at
p
H 7.0.
Nitrification of Aspartate by
Aspergillus flavus
Authors: Hatcher H. J. , Schmidt E. L.
Published: December 2020

Heterotrophic conversion of
l
-aspartic acid to nitrification products by
Aspergillus flavus
was studied in a replacement incubation system. Numerous amino acids supported nitrification; aspartate and glutamate were about equivalent as the best sources of nitrate. Addition of sodium bicarbonate to the incubation system substantially enhanced nitrate formation for all nitrifiable amino acids except aspartic acid, but the basis for the bicarbonate effect is obscure. The yield of nitrate from
l
-aspartate was not approached by forms of aspartic acid resulting from substitution on the beta carbon, the amino nitrogen, or the gamma carboxyl group or by aspartate presented as the
d
-configuration. There was no relationship between nitrate formation and the occurrence of such possible intermediates as nitrite, bound hydroxylamine, ammonia, aspergillic acid, and beta-nitropropionic acid. Uniformly labeled
14
C-
l
-aspartate that was nitrified in replacement incubation led to no accumulation of label in possible nitrification products in the culture filtrate. Label was found in components of the mycelium after acid hydrolysis, with heaviest accumulation in what appeared to be glucosamine and an unidentified compound, possibly acetylglucosamine. Detectable label was redistributed into serine, glycine, and threonine.
Uptake and Incorporation of Amino Acids and Peptides by
Bacteroides amylophilus
Authors: Hullah W. A. , Blackburn T. H.
Published: December 2020

Bacteroides amylophilus
H-18 demonstrated a higher growth yield, a slightly higher growth rate, and a diminished lag period when Tryptose was added to the basal medium. This uptake of labeled amino acids was concentration-dependent, as the contribution of exogenous amino acid to the cell protein increased from 15.4 to 24.1% when the concentration of Casamino Acids in the medium was increased from 1.4 to 2.8 mg/ml. There was considerable redistribution of
14
C-label to other amino acids. Tryptic peptides of casein competed effectively with the amino acids for uptake. The
14
C-label from a protein was incorporated into
B. amylophilus
H-18 cells presumably after breakdown of the protein by the
B. amylophilus
H-18 protease.
Comparison of the Rates of Motility of
Salmonella
with Those of Other Enteric Bacteria
Authors: Greenfield J. , Bigland C. H.
Published: December 2020

Comparison of the rates of motility through a semisolid medium of 16 common
Salmonella
sp., 14
Escherichia coli
serotypes, 4
Arizona
strains, 2
Escherichia freundii
(
Citrobacter
) isolates, 2
Proteus
sp., and 2
Pseudomonas
sp. revealed the following. (i) Very closely related bacteria could demonstrate markedly different rates of progression. (ii) All of the salmonellae tested advanced faster than the
Proteus
and
Pseudomonas
test cultures but some
Salmonella
sp., notably
S. choleraesuis
and
S. typhi
, progressed relatively slowly compared to many other test cultures. (iii) The mean rate of motility for the fastest 14
Salmonella
sp. (1.49 cm/hr) was not statistically greater than the mean value for the 14
E. coli
serotypes (1.31 cm/hr) at the 1% level of significance. Selective motility procedures may not be a reliable means of isolating all
Salmonella
sp. from materials contaminated with other bacteria.
Growth of Pathogenic Virus in a Large-Scale Tissue Culture System
Authors: Klein Frederick , Jones William I. , Mahlandt Bill G. , Lincoln Ralph E.
Published: December 2020

A model system is described for the mass propagation of Rift Valley fever (RVF) virus, utilizing large-volume fermentor units for suspension culture of tissue cells and the subsequent production of virus. Comparisons between laboratory- and fermentor-scale operations of tissue cell growth gave equivalent results. Cell viability dropped 24 to 30 hr postinfection with a subsequent virus yield between 10
8.0
and 10
9.0
mouse intracerebral median lethal doses per milliliter. Infecting volumes of tissue cell culture (20- or 40-liter working volumes) had no apparent effect on virus yields. Tissue cells grown under either oxidation-reduction potential- and
p
H-controlled or uncontrolled conditions showed little or no difference in their ability to produce RVF virus. We believe this tissue cell virus process to have potential application for large-scale production of vaccines for human or veterinary use or for the mass propagation of certain carcinogenic viruses for cancer research, once use of established lines for this purpose is accepted.
Polyacrylamide Gel Identification of Bacterial L-Forms and
Mycoplasma
Species of Human Origin
Authors: Theodore Theodore S. , Tully Joseph G. , Cole Roger M.
Published: December 2020

Polyacrylamide gel electrophoretic patterns of acidified phenol extracts prepared from whole cells can be used for the identification of bacterial L-forms and
Mycoplasma
species of human origin. Ten human
Mycoplasma
serotypes and eight L-forms belonging to five different genera were studied. The gel patterns were sufficiently distinct and reproducible that it was possible not only to identify L-forms at the genus level (group with streptococci) and different
Mycoplasma
serotypes but also to differentiate between the two of them. The parentage of L-forms of
Streptobacillus moniliformis
L1,
Listeria monocytogenes, Streptococcus
MG, and
Staphylococcus aureus
Smith strain was established by relating their gel patterns directly to parent bacteria. It was found that an L-form designated
S. moniliformis
An (ATCC 14220) was actually an L-form of
Proteus.
In addition, it was shown electrophoretically that no relationship existed between the
Streptococcus
MG L-form and
M. pneumoniae.
The applicability of this method as a diagnostic and taxonomic tool for the differentiation of L-forms and mycoplasmas is discussed.
Cultivation of Mycoplasmas on Glass
Authors: Purcell R. H. , Valdesuso J. R. , Cline W. L. , James W. D. , Chanock R. M.
Published: December 2020

Eight
Mycoplasma
species of human origin were successfully cultivated on glass. Complement-fixing (CF) antigens prepared from glass-adherent mycoplasmas were potent, specific, and free from anticomplementary activity. PPLO broth medium supplemented with 1 to 5% PPLO serum fraction (bovine), 2.5% fresh yeast extract, and 1% glucose (glycolytic species) or 1% arginine (arginine-utilizing species) supported moderate to luxuriant growth of mycoplasmas on glass. The potency of CF antigens prepared from glass-adherent mycoplasmas varied with the species of
Mycoplasma
tested and the duration of incubation. When the potency of CF antigens prepared from glass-adherent mycoplasmas was compared with that material sedimented from the broth phase of the same culture, three patterns of growth were observed:
M. hominis
and
M. orale
type 2 grew preferentially in the broth phase;
M. salivarium, M. orale
types 1 and 3,
M. pneumoniae
, and
M. lipophilum
preferentially adhered to the glass; and
M. fermentans
was biphasic. The growth of mycoplasmas on glass provides a simple means of concentrating and purifying such organisms for immunological and biochemical studies.
Differential Identification of
Mycobacterium kansasii
and
Mycobacterium marinum
Authors: Silcox Vella A. , David Hugo L.
Published: December 2020

This report deals with the differential diagnosis between
Mycobacterium marinum
and
M. kansasii.
We found that the two species could be differentiated by using six main tests, namely, the nitrate reduction test, the arylsulfatase test, the ability to grow in the presence of 10.0 μg of amithiazone per ml, the ability to grow in the presence of 5.0 μg of kanamycin per ml, the temperature-ratio test, and the rate of growth on solid medium. In contrast to
M. kansasii
, considerable variation was observed among strains of
M. marinum.
However, the evidence obtained was not considered sufficient to justify the conclusion that more than one species was represented among the strains identified as
M. marinum.
Replication of Venezuelan Equine Encephalomyelitis Virus In Vitro
Authors: Hearn H. J. , Tribble H. R. , Nagle S. C. , Bowersox O. C.
Published: December 2020

An attempt was made to identify nutritional additives that influence the replication of Venezuelan equine encephalomyelitis virus in suspension cultures grown in a defined serum-free medium. Proline, serine, and choline enhanced titers of the virulent PES strain; the progeny population, however, possessed a virulence character that was somewhat different from that of the PES inocula. These nutritional supplements did not appreciably influence the titers of the attenuated 9t and 20t viral strains. When both the PES and 20t strains were employed as a mixed inoculum in culture, the presence of the latter strain appeared to interfere with the growth of the PES strain and reduced its response to the medium supplements.
Salmonella
Screening Procedure with Tests for β-Galactosidase and Flagellar Antigens
Authors: Wilson Clyde R. , Padron Adriano P. , Dockstader W. B.
Published: December 2020

Differentiation of
Salmonella
from other gram-negative bacilli requires several biochemical and serological tests. A simplified 24-hr screening procedure has been devised which allows discarding of large numbers of isolates (picked from selective plating media) before they are subjected to this extensive testing. Cultures of gram-negative organisms isolated to triple sugar-iron slants during routine examination of products for
Salmonella
were tested for the presence of β-galactosidase and
Salmonella
flagellar antigens. β-Galactosidase-positive cultures which did not agglutinate in polyvalent flagellar antiserum were considered to be nonsalmonellae. Of 1,103
Salmonella
cultures tested, none of the 61 different serotypes was missed by this procedure, whereas 673 (82.3%) of 818 nonsalmonellae were excluded from further testing. This screening procedure eliminates most nonsalmonellae and augments the proportion of cultures undergoing further biochemical and serological testing which will be confirmed as
Salmonella.
Method for Studying Particle Size and Infective Potential of Infectious Bovine Rhinotracheitis Virus Aerosols
Authors: Thornley William R.
Published: December 2020

A technique is described for estimating the number of potential respiratory infectious loci of aerosolized infectious bovine rhinotracheitis virus.
Amino Acid Requirements of
Aeromonas
Authors: Rouf M. A. , Weber Phillip L. , Rigney Mary M.
Published: December 2020

Four of the 12 cultures of
Aeromonas hydrophila
, 5 of the 10
A. shigelloides
, and 9 of the 10
A. salmonicida
that were studied required arginine and lysine, among other amino acids, for their growth.
Comparison of the Pulmonary Bactericidal Capacity of Mice and Rats Against Strains of
Pseudomonas aeruginosa
Authors: Southern Paul M. , Pierce Alan K. , Sanford Jay P.
Published: December 2020

After aerosol deposition of
Pseudomonas aeruginosa
strains in mice and rats, completely different patterns of pulmonary bacterial clearance were observed in each animal species.
Increased Recovery Rate of Salmonellae from Stream Bottom Sediments Versus Surface Waters
Authors: Hendricks Charles W.
Published: December 2020

Salmonella
recovery rates for stream bottom sediments were observed to be higher than those from surface water.
Relationship of the Frequency of Isolation of Salmonellae to Their Resistance to Drying and Freezing
Authors: Enkiri Nancy K. , Alford John A.
Published: December 2020

The resistance of different
Salmonella
serotypes to drying and freezing has been shown to be related to their incidence in salmonellosis.
Interferon-Inducing Characteristics of MM Virus
Authors: Giron D. J. , Allen P. T. , Pindak F. F. , Schmidt J. P.
Published: December 2020

Interferon induction by MM virus in mice and in L cells was studied. In mice the virus readily induced interferon. The time of appearance was dose-dependent. A large virus dose induced interferon by 4 hr, whereas a small dose resulted in interferon production which paralleled virus replication 24 hr after infection. In L cells the interferon-inducing capacity of the virus was rapidly destroyed by ultraviolet light irradiation. Heating (56 C) of the virus, on the other hand, greatly increased its ability to induce interferon. Interferon production could also be increased by prior treatment of the cells with homologous interferon (priming). The increase in interferon production after priming was dependent on the concentration of interferon used for priming, the length of interferon treatment, and the multiplicity of infection. It is suggested that MM virus might be useful for the further study of the mechanisms involved in the production and action of interferon.
Comparison of Microtiter Procedures with the Plaque Technique for Assay of Vesicular Stomatitis Virus
Authors: Rosenthal Leonard J. , Shechmeister Isaac L.
Published: December 2020

This paper describes a microprocedure for the tissue culture assay of vesicular stomatitis virus (VSV) and compares the sensitivity of the method with the conventional plaque assay of viral concentration. Microtiter and plaque assay methods were used in titrations, neutralization tests, and thermoinactivation studies with this virus in chick embryo fibroblasts (CEF) and L, HeLa, and PK cell lines. Titration experiments with VSV by the microtiter procedure on preformed monolayers were significantly more sensitive than the plaque assay (
P
= 0.05). The results of the neutralization tests and thermoinactivation studies also showed greater ability to detect residual virus by the microtiter procedure (
P
= 0.10). In addition, the microtiter procedure was simpler, less costly, and more rapid than the plaque assay.
Therapy of Staphylococcal Infections in Monkeys
Authors: Carlisle Harold N. , Saslaw Samuel
Published: December 2020

Intravenous inoculation of a penicillin-resistant, phage type 80/81 staphylococcus caused lethal infection in six of eight untreated monkeys. Daily intragastric administration of clindamycin hydrochloride and erythromycin stearate and intramuscular inoculation of clindamycin-2-phosphate and methicillin, all at a dose level of 50 mg/kg, was followed by mortalities of one of eight, one of eight, none of eight, and one of eight monkeys, respectively. Duration of obvious acute illness in surviving monkeys and time required for complete recovery were not significantly different in the four therapy groups with the exception that duration of acute illness in monkeys treated with clindamycin-2-phosphate (mean, 4.1 days) was significantly shorter than in monkeys given erythromycin stearate (mean, 7.1 days). In vitro sensitivity data and serum antibacterial levels would suggest that methicillin would be the least effective therapeutically, followed by erythromycin stearate and the two clindamycin preparations in that order. However, this prediction was not fulfilled in these studies in experimentally infected monkeys.
Effect of Simulated Solar Radiation and Sodium Fluorescein on the Recovery of Venezuelan Equine Encephalomyelitis Virus from Aerosols
Authors: Berendt Richard F. , Dorsey Emerson L.
Published: December 2020

Almost 90% of the Trinidad strain of Venezuelan equine encephalomyelitis (VEE) virus survived for 1 hr after aerosolization into a dark environment at 30% relative humidity (RH), and 78% survived for 1 hr at 60% RH. After exposure to simulated solar radiation (584 mcal per cm
2
per min) 0.02% of the aerosolized virus survived for 1 hr at 30% RH and 0.006% survived for 1 hr at 60% RH. When 1.0 mg of sodium fluorescein per ml was added to suspensions prior to aerosol dissemination (to determine physical loss of aerosol), no virus was detected after 30 min at either RH upon irradiation. Sodium fluorescein also exhibited some toxicity (31% survival at 60 min) for nonirradiated aerosols of VEE virus at 60% RH; no effect was noted at 30%.
Microorganisms of the San Francisco Sour Dough Bread Process
Authors: Sugihara T. F. , Kline Leo , Miller M. W.
Published: December 2020

Two hundred isolates from San Francisco sour dough French bread fermentations (40 from each of five different bakeries) were screened by fermentation tests and for their ability to grow in the presence of cycloheximide (Actidione). All of the isolates from four of the bakeries and 70% of those from the fifth were unable to utilize maltose but grew well on other sugars, even in the presence of cycloheximide. The remaining few isolates from the fifth bakery utilized maltose but not galactose and were inhibited by cycloheximide. No bakers' yeast types were found. Sixteen of the maltose-negative and five of the galactose-negative isolates were subjected to more rigorous taxonomic procedures. All of the maltose-negative isolates were identified as asporogenous strains of
Saccharomyces exiguus
(
Torulopsis holmii
) and the galactose-negative ones, as
S. inusitatus
. The predominance of
S. exiguus
, its vigor in the particular acidic environment of the sour dough, and the correlation of its numbers with the leavening function constitute strong evidence on the role of this organism in the sour dough system.
Microorganisms of the San Francisco Sour Dough Bread Process
Authors: Kline Leo , Sugihara T. F.
Published: December 2020

A medium was developed which permitted isolation, apparently for the first time, of the bacteria responsible for the acid production in the 100-year-old San Francisco sour dough French bread process. Some of the essential ingredients of this medium included a specific requirement for maltose at a high level, Tween 80, freshly prepared yeast extractives, and an initial
p
H of not over 6.0. The bacteria were gram-positive, nonmotile, catalase-negative, short to medium slender rods, indifferent to oxygen, and producers of lactic and acetic acids with the latter varying from 3 to 26% of the total. Carbon dioxide was also produced. Their requirement for maltose for rapid and heavy growth and a proclivity for forming involuted, filamentous, and pleomorphic forms raises a question as to whether they should be properly grouped with the heterofermentative lactobacilli.
Survival of
Salmonella anatum
Heated in Various Media
Authors: Moats W. A. , Dabbah Roger , Edwards V. M.
Published: December 2020

Survival of
Salmonella anatum
heated at 55 C for 35 min was determined in solutions of various chemical constituents of foods including salts, carbohydrates, amino acids, peptides, nucleic acids, gums, and stabilizers and compared with survival in 0.1
m
phosphate buffer (
p
H 7.0). Commercially sterilized whole milk gave the most protection against heat. Trypticase Soy Broth, various peptide mixtures, and some amino acids gave substantial protection. Results with carbohydrates were variable, with mannitol, sucrose, and rhamnose providing substantial protection and glucose decreasing heat resistance. A few other substances, cysteine, glutathione, and sodium citrate, also decreased heat resistance. Pure proteins had little effect. Results show that water activity is of little significance under the test conditions. Protection from heat probably results from complexing of substances with heat-sensitive proteins in the cells. Autoclaved milk should not be considered equivalent to raw milk for studies of survival of bacteria during heating.
Production of Bacterial Cells from Methane
Authors: Sheehan Brian T. , Johnson Marvin J.
Published: December 2020

A mixed methane-oxidizing bacterial culture capable of stable and predictable growth in continuous culture was isolated. The culture consisted of two types of gram-negative nonsporulating rods resembling pseudomonads. The culture grew well at 45 C on an inorganic medium without asepsis. Specific metal requirements for Ca
2+
, Cu
2+
, MoO
4
2−
, Zn
2+
, Mn
2+
, Mg
2+
, and Fe
3+
(or Fe
2+
) were shown. The cells grown in continuous culture contained 11.7 to 12.1% total nitrogen. From an animal nutrition standpoint, the distribution of amino acids was satisfactory. The continuous fermentation was operated over a range of steady-state dilution rates from 0.085 to 0.301 hr
−1
. The maximum specific growth rate for the culture, μ
max
, was 0.303 hr
−1
(doubling time 2.29 hr). The average yield for all fermentations analyzed was 0.616 g (dry weight of cells per g of methane used and 0.215 g (dry weight) of cells per g of oxygen used. The yields on both methane and oxygen were higher for the oxygen-limited than for the methane-limited fermentations. The maximum productivity attained in the fermentor was 2.39 g (dry weight) of cells per hr per liter at a dilution rate of 0.187 hr
−1
and a cell concentration of 12.8 g (dry weight) of cells per liter. The limit on maximum cell productivity was determined only by the mass transfer rate of oxygen in the fermentor. The simultaneous volumetric mass-transfer coefficients (k
L
a in hr
−1
) for oxygen and methane were determined. The results appear to indicate an oxygen to methane mass-transfer coefficient ratio of approximately 1.4.
Factors Affecting Phosphate Uptake by
Aerobacter aerogenes
in a System Relating Cell Numbers to
32
P Uptake
Authors: White Lloyd A. , MacLeod Robert A.
Published: December 2020

The uptake of phosphate, from media limited in this ion, by resting cells of
Aerobacter aerogenes
has been investigated and shown to be dependent upon several factors. An incubation medium composed of 10
−2
m
K
+
, 5 × 10
−3
m
Mg
2+
, 1 mg of glucose per ml, and 1 μCi of
32
PO
4
3−
per ml, buffered at
p
H 6.55 with 0.05
m
N
-2-hydroxyethyl-piperazine-
N
′-2-ethanesulfonic acid (HEPES), was found to stimulate optimum accumulation of
32
P-orthophosphate. The temperature of incubation, incubation time, the concentration of unlabeled orthophosphate, as well as arsenate, and several metabolic inhibitors were found to affect the accumulation. The labeled cells were collected on a membrane filter, which had been previously boiled in glass-distilled water, for measurement of the radioactivity accumulated. Under optimum conditions, as few as 20,000 cells were capable of accumulating detectable amounts of
32
P-orthophosphate in 1 hr of incubation.
Classification of
Streptomyces
Spore Surfaces into Five Groups
Authors: Dietz Alma , Mathews John
Published: December 2020

Streptomyces
spores surfaces have been classified into five groups, smooth, warty, spiny, hairy, and rugose, by examination of carbon replicas of spores with the transmission electron microscope and by direct examination of spores with the scanning electron microscope.
Fungi Isolated from Flue-Cured Tobacco Inoculated in the Field with Storage Fungi
Authors: Welty Ronald E.
Published: December 2020

Flue-cured tobacco inoculated in the field with
A. amstelodami, A. flavus, A. ochraceus, A. repens, A. ruber
, and a species of
Penicillium
was rarely invaded by these fungi. Regardless of inoculum, the predominant fungi reisolated from green tissue were species of
Alternaria
and
Cladosporium
. After curing,
A. repens, A. niger
, and species of
Alternaria
and a species of
Penicillium
were the most commonly isolated fungi. The fungus used as inoculum was not the predominant fungus reisolated from green or cured tissue. Conditions during handling and storage prior to marketing probably determine when storage fungi become associated with the leaf and which species becomes predominant.
Production of a Naphthoquinone Pigment by a Species of
Streptoverticillium
and Its Accumulation by a Streptomycete
Authors: Tresner H. D. , Hayes Jean A. , Borders D. B.
Published: December 2020

A naphthoquinone pigment produced by a species of
Streptoverticillium
was accumulated by a
Streptomyces
sp. when the two organisms were grown in mixed cultures.
Antimicrobial Activity of Sodium
n
-Alkylsalicylates
Authors: Buckley D. , Thomas J.
Published: December 2020

The activities are reported of sodium salts of several
n
-alkylsalicylic acids against
Staphylococcus aureus, Pseudomonas aeruginosa, Mycobacterium phlei
, and
Candida albicans
. The acids had alkyl substituents of 1 to 18 carbon atoms in the 3, 4, or 5 positions relative to the carboxyl group of salicylic acid. Generally, the antimicrobial properties were typical of anionic surface-active agents although the salicylates are more potent than most of these, particularly against
S. aureus
.
Effect of Chlorite-Oxidized Oxyamylose on Influenza Virus Infection in Mice
Authors: Billiau A. , Muyembe J. J. , De Somer P.
Published: December 2020

Intraperitoneally administered chlorite-oxidized oxyamylose (COAM) provided protection of mice against intranasal infection with several influenza virus strains. Treated animals invariably showed a reduced consolidation of the lungs and, in the case of infection with lethal strains of virus, also a delay in mortality. With a small dose of influenza A/PR8 virus, an increase in final survival rate could be observed. The effect of COAM on influenza virus infection lasted for at least 4 to 8 days. Inhibition of lung consolidation was not paralleled by a decrease in virus multiplication in the lung. The significance of this finding in relation to the mechanism of the antiviral action of COAM is discussed.
Free and Immobilized Glucose Isomerase from
Streptomyces phaeochromogenes
Authors: Strandberg Gerald W. , Smiley Karl L.
Published: December 2020

Properties were determined of the glucose isomerase from
Streptomyces phaeochromogenes
NRRL B-3559. The enzyme exhibited a temperature optimum of 80 C and a
p
H optimum of about 8. The effect of various buffers on activity of the enzyme and the optimum
p
H were studied. Michaelis constants for glucose and Mg
2+
were 0.25 and 0.025
m
, respectively. Co
2+
enhanced enzyme activity. A functional polyacrylamide-entrapped glucose isomerase was prepared. The conditions for entrapment and use of the bound enzyme were examined.
Inactivation of Influenza and Other Viruses by a Mixture of Virucidal Compounds
Authors: Oxford J. S. , Potter C. W. , McLaren C. , Hardy W.
Published: December 2020

A mixture of benzalkonium chloride, Triton X100, and citric acid (Resiguard F) had a marked virucidal effect on lipid-containing deoxyribonucleic and ribonucleic acid viruses, such as vaccinia virus, herpesvirus, and influenza virus. Adenoviruses and picornaviruses were more resistant to inactivation. Electron microscopy showed that influenza particles became aggregated in the presence of Resiguard F and that the outer fringe of hemagglutinin and neuraminidase spikes seen in control virus preparations became indistinct. The mixture had no detectable antiviral activity in mice infected with influenza AO/PR/8/34 virus, and this was attributed to the reduced virucidal effect of Resiguard F in the presence of serum proteins.
Methods for Accelerating the Fluorescent-Antibody Test for Rabies Diagnosis
Authors: Larghi Oscar P. , Ch Edwin Jimenez
Published: December 2020

The time required to perform the fluorescent-antibody test for rabies was reduced by eliminating acetone fixation of the brain impressions and by incubating the conjugate-impression reaction at room temperature for only 10 min. Elimination of the preliminary acetone fixation had no effect on the diagnosis of impression smears from 246 mammalian brains by immunofluorescence. Staining at 37 C for 30 min and staining at room temperature for 10 min were found to be equally effective in the examination of impression smears from 161 brain samples. The procedure, as modified, shortens the time required for the diagnosis of rabies by immunofluorescence from about 5.5 hr to approximately 45 min.
Batch Production of Protein from Ethane and Ethane-Methane Mixtures
Authors: Volesky B. , Zajic J. E.
Published: December 2020

A culture of
Graphium
grows upon natural gas and a mineral salt solution. Ethane is the preferred substrate but methane is co-utilized. A stirred-tank type fermentor was used to study batch growth. Maximum production rate of biomass was 80 mg/liter·hr, at
p
H 4, using simple synthetic supporting medium with ammonium sulfate as a nitrogen source. This rate was observed after 40 hr of fermentation. A doubling time of 3.7 hr was observed. The corresponding specific growth rate was 0.187 per hr. A magnetic drive fermentor was used to study the effect of continuous recycle of gases in a gas-tight system. The rate of oxygen utilization is approximately 2.1 times higher than for ethane. Oxygen must not be allowed to become limiting in recycle gases. The calculated efficiency of overall biomass synthesis averages 30%. Hyphal and unicellular tissue of
Graphium
contains 52% protein. It compares favorably with standard FAO protein in its content of amino acids.
Sensitive Matrix Gel Diffusion Test for the Detection of Australia Antigen
Authors: Hartwell W. V. , Maynard J. E. , Berquist K. R.
Published: December 2020

A matrix gel diffusion (MGD) procedure with a sensitivity comparable to the complement fixation test (CF) has been developed for detecting Australia antigen in serum. The test utilizes a thin layer of agar (0.1 mm) with an applied plastic matrix. Reactants are introduced directly onto the surface of the agar through wells in the plastic matrix. End points obtained by CF with a panel of 11 sera varied from 1:8 to 1:512. When these sera were tested by MGD, end points for detection of antigen were within one dilution of that obtained by CF.
Capillary Tube Immunological Assay for Staphylococcal Enterotoxins
Authors: Gandhi N. R. , Richardson G. H.
Published: December 2020

A simple assay is reported in which 1 μg of staphylococcal enterotoxins A, B, and D per ml was detected in less than 1 hr. Interfacial reaction of antisera and enterotoxin solutions in a 1-ml internal diameter capillary tube allowed rapid detection of sera type.
Tetracycline Inhibition of a Lipase from
Corynebacterium acnes
Authors: Weaber K. , Freedman R. , Eudy W. W.
Published: December 2020

A lipase which hydrolyzes triglycerides (tricaprylin and trilaurin) and naphthyl laurate was obtained from the broth of
Corynebacterium acnes
cultures by ammonium sulfate fractionation. Ca
2+
and sodium taurocholate stimulated activity of the enzyme. Ethylenediaminetetraacetic acid (EDTA) did not inhibit activity of the Ca
2+
-activated enzyme, but lipolytic activity was inhibited by EDTA in the absence of Ca
2+
. Tetracycline (10
−4
m
) produced a slight inhibition of the lipase activity with 5 × 10
−5
m
or less showing no effect on the lipase activity. However, complete inhibition by tetracycline at 10
−4
m
was observed for Ca
2+
-activated enzyme. Tetracycline inhibition of the
C. acnes
lipase could be demonstrated at concentrations as low as 10
−6
m
.
Potentially Infectious Agents Associated with Shearling Bedpads: Effect of Laundering with Detergent-Disinfectant Combinations on
Staphylococcus aureus
and
Pseudomonas aeruginosa
Authors: Wilkoff L. J. , Dixon G. J. , Westbrook L. , Happich W. F.
Published: December 2020

Glutaraldehyde-tanned woolskins which are used as bedpads to prevent decubitus ulcers were contaminated with
Staphylococcus aureus
(ATCC 6538) and
Pseudomonas aeruginosa
(ATCC 15442). Two methods of exposure, direct contact and aerosol, were used in separate experiments. Attempts were made to decrease the bacterial population placed on the woolskins by laundering them in a quaternary ammonium disinfectant, a phenolic disinfectant, or alkalinized glutaraldehyde, in combination with an anionic or nonionic detergent. The effect of a commercial detergent-sanitizer was also studied. Bacterial populations were significantly reduced in all experiments, but only laundering in glutaraldehyde in combination with either detergent resulted in maximum removal of bacteria. Viable bacteria were usually not detected in the rinse water (<1 viable organism/5 ml of rinse water).
Rapid Quantitative Method for
Salmonella
Detection in Polluted Waters
Authors: Cheng Chu Ming , Boyle William C. , Goepfert J. M.
Published: December 2020

A procedure has been developed for the enumeration of salmonellae in polluted waters using several modifications of existing techniques. Confirmation of salmonellae is achieved within 48 hr. This procedure includes selective enrichment in m-Tetrathionate Broth (22 ± 1 hr), plating on Brilliant Green Sulfa Agar (20 ± 1 hr), and confirmation by flagellar (H) agglutination of the growth in a mannosecontaining medium (6 ± 1 hr). An incubation temperature of 41.5 C was used throughout this procedure. Dilution to extinction techniques (most probable number) were employed to enumerate salmonellae. Large sample volumes were concentrated through the use of membrane filters. This technique proved to be rapid and reliable for the enumeration of salmonellae in water, waste water, and waste-water sludges.
Correlation of Biological to Chromatographic Data for Two Mycotoxins Elaborated by
Fusarium
Authors: Burmeister H. R. , Ellis J. J. , Yates S. G.
Published: December 2020

Thirty-seven identified strains of
Fusarium
, most of them isolated from fescue grass, were tested for their ability to elaborate mycotoxins in laboratory culture. The presence of the toxins was determined by infrared light, thin-layer chromatography, mouse toxicity, fungistatic effects, and phytotoxic properties. A good correlation was demonstrated between T-2 toxin detection by thin-layer chromatography and inhibition of
Rhodotorula rubra
by culture extracts. All of the strains producing either butenolide or T-2 toxin were toxic to mice with but one exception; those producing T-2 toxin inhibited growth of the yeast.
R-Factor Transfer in Selenite and Tetrathionate Broths
Authors: Gardner Pierce , Harding A. Lynn , Olans Richard N. , Smith David H.
Published: December 2020

After overnight incubation of R
+
Escherichia coli
with R
−
Salmonella typhimurium
in selenite and tetrathionate with Brilliant Green (TBG) broths, R-factor transfer was demonstrated in 10 of 12 experiments. R-factor transfer in these enrichment broths occurred at a markedly reduced frequency in comparison to that in Trypticase soy broth, apparently due to an adverse effect either on the viability of the donor
E. coli
or the conjugation process itself. Transfer of R factors in commonly used enrichment broths may give rise to falsely resistant antibiotic patterns in
Salmonella.
However, the frequency of R-factor transfer is so low that it is unlikely to affect significantly the interpretation of R-factor studies.
Immunity to Aerosol Challenge in Guinea Pigs Immunized with Gamma-Irradiated Venezuelan Equine Encephalitis Vaccines
Authors: Reitman Morton , Tonik Ellis J.
Published: December 2020

In a previous report, it was shown that nonviable Venezuelan equine encephalitis (VEE) vaccines prepared by exposure of virus suspensions produced in WI-38 cells to ionizing radiations were highly effective in protecting guinea pigs subjected to intraperitoneal (ip) challenge with VEE virus. To characterize further the efficacy of irradiated vaccines, guinea pigs were immunized with three lots of vaccine inactivated by exposure to 8 × 10
6
r of gamma rays and then were challenged via the respiratory route with aerosols of VEE virus. Animals that received a series of three ip inoculations of vaccine at 1-week intervals showed high levels of resistance to aerosol challenge. The 50% effective dose values of vaccines ranged from <0.0016 to 0.0051 ml for respiratory challenge and from <0.00074 to 0.0011 ml for intraperitoneal challenge. Serological studies showed that antigenicity of the irradiated vaccines was excellent. Moderate to high levels of serum-neutralizing and hemagglutination-inhibiting antibodies were demonstrated in the majority of animals vaccinated with undiluted or 10
−1
dilutions of the vaccines. However, serum-neutralizing and hemagglutination-inhibiting antibody levels were not always indicative of the level of immunity, because some animals in which significant antibody could not be demonstrated were able to survive challenge with VEE virus.
Concentration and Purification of Viruses by Adsorption to and Elution from Insoluble Polyelectrolytes
Authors: Wallis Craig , Melnick Joseph L. , Fields Joseph E.
Published: December 2020

Acid-resistant, nonenveloped viruses belonging to the enterovirus, reovirus, and adenovirus groups were readily concentrated on PE60, an insoluble cross-linked polyelectrolyte based on isobutylene maleic anhydride. Hydrolysis of PE60 by NaOH increased its capacity to adsorb viruses. Hydrogen ion levels played an important role in virus concentration; optimal
p
H levels for maximal virus adsorption were between
p
H 3.0 and 4.5. Undiluted virus was easily concentrated from large volumes on PE60, and the adsorbed virus was readily eluted at
p
H 8 to 9.
In Vitro Studies of Semisynthetic α- (Substituted-Ureido) Penicillins
Authors: Bodey Gerald P. , Stewart Dorothy
Published: December 2020

The activity of three α-(substituted-ureido) penicillins was evaluated in vitro against 599 clinical isolates of gram-negative bacilli, by use of the broth-dilution technique. At a concentration of 12.5 μg or less/ml, BL-P1597 inhibited 90% of isolates of
Pseudomonas
sp., 56% of
Enterobacter
sp., 67% of indole-positive
Proteus
spp., 72% of
Escherichia coli
, and 85% of
Proteus mirabilis.
BL-P1654 had similar activity, whereas BL-P1532 was much less active. At a concentration of 25 μg or less/ml, BL-P1597 also inhibited nearly 60% of isolates of
Klebsiella
sp. and nearly 40% of
Serratia
sp. BL-P1597 and BL-P1654 were as active as ampicillin and carbenicillin against
E. coli
and
P. mirabilis.
They were less active than carbenicillin against indole-positive
Proteus
spp. Both drugs were substantially more active than carbenicillin against
Pseudomonas
sp. A strain of
Pseudomonas
sp. which developed resistance to carbenicillin also developed resistance to the α-(substituted-ureido) penicillins simultaneously.