bluuebunny/crossref_metadata_2025 huggingface dataset:
Amino Acid and Vitamin Requirements of Several
Bacteroides
Strains
Authors: Quinto Grace
Published: December 2020

Nutritional studies were performed on nine
Bacteroides
strains, by use of the methodology and media of anaerobic rumen microbiology.
Ristella perfoetens
CCI required
l
-arginine hydrochloride,
l
-tryptophan,
l
-leucine,
l
-histidine hydrochloride,
l
-cysteine hydrochloride,
dl
-valine,
dl
-tyrosine, and the vitamin calcium-
d
-pantothenate, since scant turbidity developed in media without these nutrients.
R. perfoetens
was stimulated by glycine,
dl
-lysine hydrochloride,
dl
-isoleucine,
l
-proline,
l
-glutamic acid,
dl
-alanine,
dl
-phenylalanine,
dl
-methionine, and the vitamins nicotinamide and
p
-aminobenzoic acid, since maximal turbidity developed more slowly in media without these nutrients than in complete medium. Medium A-23, which was devised for
R. perfoetens
, contained salts, 0.0002% nicotinamide and calcium
d
-pantothenate, 0.00001%
p
-aminobenzoic acid, 0.044%
l
-tryptophan, 0.09%
l
-glutamic acid, and 0.1% of the other 13 amino acids listed above.
Zuberella clostridiformis
and seven strains of
R. pseudoinsolita
did not require vitamins, and showed no absolute requirement for any one amino acid. Various strains produced maximal turbidity more slowly in media deficient in
l
-proline, glycine,
l
-glutamic acid,
dl
-serine,
l
-histidine hydrochloride,
dl
-alanine, or
l
-cysteine hydrochloride, than in complete medium. These eight strains grew optimally in medium A-23 plus 0.1%
dl
-serine but without vitamins.
Potency of Adenovirus Vaccines: Comparison of Unconcentrated, Concentrated, and Soluble Antigen Preparations
Authors: Strauss R. R. , Goulet N. R. , Liu O. C. , Beiler J. M.
Published: December 2020

Five adenoviruses were effectively concentrated and partially purified by methanol precipitation. The soluble antigens from one adenovirus concentrate were obtained by adsorption to and elution from calcium phosphate. Formaldehyde-inactivated vaccines prepared from the virus concentrates were more antigenic in guinea pigs than a National Institutes of Health reference vaccine or one prepared from unconcentrated adenovirus. The soluble antigens also proved to be antigenic. The data indicate that adenovirus vaccines of superior potency can be prepared from concentrated virus preparations and that the extracted soluble antigens are immunogenic.
Steroid Interference with Antifungal Activity of Polyene Antibiotics
Authors: Zygmunt Walter A. , Tavormina Peter A.
Published: December 2020

Wide differences exist among the polyene antibiotics, nystatin, rimocidin, filipin, pimaricin, and amphotericin B, with reference to steroid interference with their antifungal activities against
Candida albicans
. Of the numerous steroids tested, ergosterol was the only one which effectively antagonized the antifungal activity of all five polyene antibiotics. The antifungal activities of nystatin and amphotericin B were the least subject to vitiation by the addition of steroids other than ergosterol, and those of filipin, rimocidin, and pimaricin were the most sensitive to interference. Attempts to delineate the structural requirements of steroids possessing polyene-neutralizing activity in growing cultures of
C. albicans
are discussed. The ultraviolet absorbance of certain antibiotic steroid combinations was also studied.
Prevention of the Emergence of Drug Resistance in Bacteria by Acridines, Phenothiazines, and Dibenzocycloheptenes
Authors: Heller Carole S. , Sevag M. G.
Published: December 2020

It has been found that, like Atabrine, the phenothiazine tranquilizers promazine, chlorpromazine, promethazine, levopromethazine, and Stelazine; the antidepressants (dibenz-azepine and dibenzocycloheptene derivatives) Tofranil, Pertofrane, cyclobenzaprine, Elavil, protriptyline, and 3-chlorodibenzocycloheptene; and the acridine derivatives acridine orange, acriflavin, SKF no. 16214-A2, SKF no. 13231-A2, SKF no. 9200, and SKF no. 9836 are all to a greater or lesser extent than Atabrine, effective in preventing the emergence of resistant strains of
Staphylococcus aureus
and
Escherichia coli
in the presence of streptomycin, sulfathiazole, or chloramphenicol. The antimalarials chloroquine and hydroxychloroquine were also studied and found to be ineffective. The medical significance of these findings is discussed, as well as the effect of the structural variations of these compounds on their relative activities.
Simple Cultural Test for Relative Cellulolytic Activity of Fungi
Authors: Rautela Gopal S. , Cowling Ellis B.
Published: December 2020

A simple method is described for determining the relative cellulolytic activity of fungi. Opaque columns of an agar medium containing a partially crystalline cellulose preparation were inoculated with the fungi. Depth of the clear zone that developed beneath the growing cultures provided a visual measure of cellulolytic activity on a continuous, cumulative basis. Depth of clearing (DC) was determined for 25 species of fungi differing widely in cellulolytic activity, and compared by correlation analysis with results of three other methods for measuring cellulolytic activity. Relatively high coefficients of correlation (greater than 0.6) were obtained between DC and weight loss of cotton sliver, loss in tensile strength of cotton duck, and carboxymethyl cellulase activity in culture filtrates. In comparison with conventional assay procedures, the clearing method offered several advantages: (i) results were at least as well correlated with the capacity to utilize native cellulose as a substrate; (ii) the method measured activity of growing cultures rather than culture filtrates, thus involving less risk of losses due to product inhibition, binding, or denaturation of enzymes; (iii) repeated measurements were made on the same experimental set up, so that errors due to arbitrarily selected times of harvest were avoided conveniently; and (iv) the method required less working time and very simple equipment, making it convenient for large-scale screening tests.
Survival of
Clostridium perfringens
During Baking and Holding of Turkey Stuffing
Authors: Woodburn Margy , Kim Chung H.
Published: December 2020

Vegetative cells of three strains of
Clostridium perfringens
were used as inoculum for bread and onion stuffing for eight lightweight and eight heavyweight turkeys. When stuffed turkeys were refrigerated (5 ± 1 C for 24 ± 2 hr), a mean count of 580 vegetative cells of
C. perfringens
per gram of stuffing was reduced to undetectable levels (<6 per gram) in six of the eight. An inoculum of spores of the three strains used in a second series survived refrigerated holding with no change in numbers. During cooking of the stuffed turkeys in an oven at 94 C, numbers of vegetative cells fell steadily and numbers of spores remained constant or increased slightly (2 of 16 stuffings), until the temperature of the stuffing rose above that permitting growth. Viable
C. perfringens
cells were recovered from the stuffings at the end of cooking plus 1 hr for the group inoculated with the spore suspension. Storage of these stuffings resulted in marked reductions in numbers after 6 days at 5 ± 1 C and in increases after 24 ± 2 hr at 23 ± 1 C. Cells of a strain which produces spores not considered heat-resistant survived in stuffing in birds cooked to doneness in ovens at 94, 163, and 232 C. In accepted methods of cooking stuffed turkeys,
C. perfringens
contaminants may survive and create a hazard if subsequent storage is in a temperature range which permits their multiplication.
Isolation of Thermophiles from Broadleaf Tobacco and Effect of Pure Culture Inoculation on Cigar Aroma and Mildness
Authors: English Clyde F. , Bell Emily J. , Berger Alfred J.
Published: December 2020

Thermophilic members of the genus
Bacillus
isolated from fermented Connecticut broadleaf tobacco included eight strains of
B. subtilis
, five strains of
B. coagulans
, four strains of
B. megaterium
, and three strains of
B. circulans
. Some of these strains in pure single or mixed culture were employed to enrich the normal thermophile flora of “sweating” tobacco. Three strains of
B. subtilis
and one of
B. circulans
, either in single or multiple enrichment, caused the more rapid appearance of a pleasing aroma in Pennsylvania “Wrapper B” filler tobacco. These conclusions are based on subjective reactions of professional testers after numerous blindfold smoking tests.
Effect of Various Gas Atmospheres on Destruction of Microorganisms in Dry Heat
Authors: Pheil C. G. , Pflug I. J. , Nicholas R. C. , Augustin J. A. L.
Published: December 2020

The heat resistance of dry bacterial spores was tested in various gases at temperatures ranging from 121.1 to 160 C (250 to 320 F). Spores of
Clostridium sporogenes
(PA 3679) were heated in air, carbon dioxide, and helium; spores of
Bacillus subtilis
5230 were heated in these gases and also in oxygen and in nitrogen. The surrounding gas influenced the heat resistance, but the differences among gases were small.
D
values were about 7 min at 148.9 C (300 F);
z
values were about 18.3 C (33 F) for
B. subtilis
, and about 21.7 C (39 F) for
C. sporogenes
. The resistance of
B. subtilis
in carbon dioxide was about the same as in air, but lower than in all other gases; resistance in helium and nitrogen was about the same, and was higher than in all other gases.
C. sporogenes
had the least resistance in air; the resistance was about the same in carbon dioxide and helium. For
B. subtilis
, the gases in order of increasing heat resistance were carbon dioxide, air, oxygen, helium, and nitrogen, and for
C. sporogenes
, air, carbon dioxide, and helium. Neither oxygen content nor molecular weight of the gas appeared to have a marked influence on dry-heat resistance of the spores, whereas the more inert gases seemed to yield larger
D
values.
Typing of Nontypable Staphylococci by Lysogeny
Authors: Chun Doki , Choi Sak Duk , Suh Jung Hae , Moon Young Suk
Published: December 2020

Strains of coagulase-positive staphylococci which were nontypable with the routine typing set of phages could be typed by lysogeny with phage-propagating strains as indicators and with ultraviolet induction. About 10% of the strains could be typed without induction. About 36% of them could be typed by this method when ultraviolet irradiation was used as an inducing agent. The phage groups from which the majority of the nontypable staphylococci originated were easily identified by this method of typing.
Amino Acid Concentrations in Rumen Fluid
Authors: Wright D. E. , Hungate R. E.
Published: December 2020

Methods using dialysis or ultrafiltration are described for the collection of extracellular fluid in rumen contents for analysis of amino acids. Marked differences in the concentration of aspartic acid, glutamic acid, and alanine were found in samples of either diffusate or ultrafiltrate and in clarified acidified rumen liquor. Concentrations are given for aspartic acid, glutamic acid, alanine, glycine, γ-aminobutyric acid, valine, δ-aminovaleric acid, and leucine.
Numerical Taxonomy of Gram-Positive and Catalase-Positive Rods Isolated from Frozen Vegetables
Authors: Splittstoesser D. F. , Wexler Marjorie , White Janet , Colwell R. R.
Published: December 2020

One hundred isolates from peas, beans, and corn were compared with cultures of
Corynebacterium, Microbacterium
, and
Arthrobacter
by use of numerical taxonomic procedures. Six groups (clusters), representing 75% of the isolates, resembled
Corynebacteriaceae
. There was some doubt regarding the genera represented because the groups were not closely related to many of the known strains. The relationship of the different groups to each other, as well as a number of their properties, is presented.
Radiation Sterilization of Prototype Military Foods
Authors: Anellis Abe , Berkowitz D. , Jarboe C. , El-Bisi H. M.
Published: December 2020

Ten lots of diced cured ham, packed in cans, were inoculated with approximately 10
6
Clostridium botulinum
spores per can. Each lot was seeded with a different strain (five type A and five type B strains). All cans were irradiated to various dose levels with Co
60
. Evidence provided by swelling, toxicity, and recoverable
C. botulinum
with 6,350 cans demonstrated that: (i) 4.5 Mrad was more than adequate as a sterilization dose; (ii) the minimal experimental sterilizing dose (ESD) based on nonswollen nontoxic endpoints was 2.0 < ESD ≤ 2.5 Mrad, and based on non-spoiled sterile cans was 3.0 < ESD ≤ 3.5 Mrad (the latter was supported by the computed theoretical 12
D
dose); (iii)
D
values calculated from botulinal survival data indicated that, as a group, the type A strains were more radioresistant than type B strains; strains 12885A and 41B, with respective
D
values of 0.242 and 0.175, represented the most resistant of each type; (iv) swollen cans did not always contain toxin, nor were toxic cans always swollen; (v) viable
C. botulinum
can exist for 6 months at 30 C without producing visible or toxic spoilage at doses of 3.0 Mrad and lower, including, in some instances, 0.0 Mrad; and (vi) a phenomenon similar to heat activation of spores occurred at sublethal radiation doses.
Fluorometric Method for Determining the Efficiency of Spun-Glass Air Filtration Media
Authors: Sullivan James F. , Songer Joseph R. , Mathis Raymond G.
Published: December 2020

The procedures and equipment needed to measure filtration efficiency by means of fluorescent aerosols are described. The filtration efficiency of individual lots of spun-glass air filtration medium or of entire air filtration systems employing such media was determined. Data relating to the comparative evaluation of spun-glass filter media by means of the fluorometric method described, as well as by conventional biological procedures, are presented.
Antibiotic Control of
Mycoplasma
in Tissue Culture
Authors: Perlman D. , Rahman Sharon B. , Semar Joan B.
Published: December 2020

Seven of eight strains of
Mycoplasma
(PPLO) were found to be sensitive to the deoxystreptamines, certain macrolides, and the tetracyclines. These antibiotics are relative noncytotoxic. Kanamycin and tetracycline were useful in eliminating PPLO (pleuropneumonia-like organisms) strain Squibb no. 1 from a HeLa cell line which was deliberately contaminated with PPLO. Repeated exposure of
M. laidlawii
type B cells to neomycin resulted in a 50-fold increase in resistance, and the resistant strain was also resistant to gentamicin, kanamycin, neomycin, and paromomycin. A tetracycline-resistant strain of this culture was found to be resistant to 7-chlortetracycline, 7-chlor-6-demethyltetracycline, and 5-hydroxytetracycline. One PPLO strain, Squibb no. 2, derived from a contaminated HeLa cell culture, was resistant to all antibiotics studied.
Changes in the Microflora of Irradiated Petrale Sole (
Eopsetta jordani
) Fillets Stored Aerobically at 0.5 C
Authors: Pelroy Gretchen A. , Seman John P. , Eklund Melvin W.
Published: December 2020

The microfloral changes on irradiated petrale sole fillets during aerobic (packaged with oxygen-permeable film), refrigerated storage were determined by the identification of bacterial and yeast isolates to the generic level. The samples were irradiated at 0.0, 0.1, 0.15, 0.2, 0.3, and 0.4 Mrad by use of a cobalt-60 gamma source, were stored at 0.5 C, and were examined periodically for spoilage, total microbial population, and composition. The preirradiation flora of the fresh fillets consisted of coryneforms,
Achromobacter, Micrococcus, Flavobacterium, Pseudomonas
, and
Lactobacillus
. Immediately after irradiation,
Micrococcus, Achromobacter
, coryneforms, and
Bacillus
were predominant. The flora of the nonirradiated fillets at the time of spoilage consisted of
Pseudomonas
and
Achromobacter
. The flora of the irradiated fillets at the time of spoilage consisted of
Achromobacter
and
Trichosporon
.
Factors Affecting the Resistance of
Staphylococcus aureus
to Hydrogen Peroxide Treatments in Milk
Authors: Amin V. M. , Olson N. F.
Published: December 2020

Staphylococcus aureus
196E was treated with 0.05% hydrogen peroxide in milk under varying conditions to determine the effects of treatment conditions and characteristics of the culture on bactericidal effectiveness of hydrogen peroxide. Time intervals required for 90 to 99.99% destruction of
S. aureus
decreased significantly as treatment temperatures increased from 37.8 to 57.2 C. Plots of survivor curves showed extended lags in destruction at 37.8 C, slight lags followed by logarithmic rates of destruction at 48.9 C, and logarithmic rates at 54.4 and 57.2 C except for trials in which there was very rapid initial destruction followed by logarithmic rates.
S. aureus
196E was significantly more resistant to heat treatments at 54.4 C without added hydrogen peroxide than to treatment with 0.05% hydrogen peroxide at this temperature. Cultures grown at 37 C for 16 hr in milk were more resistant to hydrogen peroxide than were cultures grown at 35 C. Storage of cultures for 96 hr in milk at 4 C caused a decrease in the resistance of the culture. Numbers of staphylococci being treated had little effect on rates of destruction.
Steroid Transformations by Species of
Cephalosporium
and Other Fungi
Authors: Sardinas Joseph L. , Pisano Michael A.
Published: December 2020

A total of 58 cultures, tentatively identified as species of the genus
Cephalosporium
, were screened in flask fermentations for their ability to effect conversions of progesterone (Δ
4
-pregnene-3,20-dione) and Reichstein's Substance S (Δ
4
-pregnene-17α,21-diol-3,20-dione). A large number of transformations were observed by means of a series of five paper chromatography systems rated for analysis of steroid compounds ranging in polarity from progesterone to polyhydroxylated steroids. Five different transformation products were selected for isolation and identification. For purposes of recovery, conversions were conducted under submerged conditions in either 4- or 200-liter fermentors in which the broth was agitated and aerated. The steroid substrate was dissolved in acetone and added aseptically to the growing culture in a final concentration of 0.025%. After the conversions were effected, the whole broth was extracted with chloroform, and the transformation products were recovered, either by direct crystallization from solvents or through the use of silica gel columns. It was determined that
C. ciferrii
21C converted progesterone to Δ
4
-androstene-3,17-dione. Kendall's Compound F (Δ
4
-pregnene-11β,17α,21-triol-3,20-dione) was converted to its 20β-ol analogue by
Geotrichum
sp. 51C (during these studies, a number of cultures were taxonomically reclassified).
Cephalosporium
sp. 27C formed the Δ
1
-analogue of Reichstein's Substance S, and
Cephalosporium sclerotigenum
31C and
Verticillium aphidum
both converted Substance S to the 6β-hydroxy derivative.
Paecilomyces persicinus
22C converted Substance S to a product believed to be a dihydroxylated derivative.
Survival of Microorganisms in a Simulated Martian Environment
Authors: Hagen C. A. , Hawrylewicz E. J. , Ehrlich R.
Published: December 2020

The effects of moisture and oxygen concentration on germination of
Bacillus cereus
and
B. subtilis
var.
niger
spores were investigated in a simulated Martian environment. Less moisture was required for germination than for vegetative growth of both organisms. A daily freeze-thaw cycle lowered moisture requirements for spore germination and vegetative growth of both organisms, as compared with a constant 35 C environment. Oxygen had a synergistic effect by lowing the moisture requirements for vegetative growth, and possibly germination, of both organisms. Oxygen was not required for spore germination of either organism, but was required for vegetative growth of
B. subtilis
and for sporulation of both organisms.
Soluble Antigens for Immunofluorescence Detection of
Histoplasma capsulatum
Antibodies
Authors: Hook William A. , Fife Earl H.
Published: December 2020

Soluble antigens from
Histoplasma capsulatum
in the mycelial and yeast phase were purified by gel filtration, fixed onto paper discs, and employed in an indirect immunofluorescence procedure to detect antibody in sera from individuals infected with
H. capsulatum
. The elution patterns of crude histoplasmin passed through Sephadex G-200 revealed two minor peaks of protein showing immunofluorescence, complement fixing, and precipitating-antigen activity. A large peak containing the pigment and other low molecular weight materials showed no serological activity. A polysaccharide antigen obtained from fragmented, deproteinized yeast-phase cells was reactive in the fluorescent-antibody test but showed no antigen activity in complement fixation or precipitin tests. Although certain sera from culturally proven cases of blastomycosis, coccidioidomycosis, and cryptococcosis reacted with the purified
Histoplasma
antigens, preliminary evaluation indicated that the immunofluorescence technique may be of value as a screening procedure for the serodiagnosis of histoplasmosis.
Sporicidal Activity of Peracetic Acid and β-Propiolactone at Subzero Temperatures
Authors: Jones Lynwood A. , Hoffman Robert K. , Phillips Charles R.
Published: December 2020

A method was developed to evaluate and measure the sporicidal activity of peracetic acid (PAA) and β-propiolactone (BPL) at subzero temperatures as low as -40 C.
Bacillus subtilis
var.
niger
spores were used as the test organism. Both PAA and BPL were sporicidal at low temperatures, with PAA the more active. The temperature coefficients of the two chemicals are generally low over a range of 20 to -20 C, but increase significantly at temperatures below this. Results showed an initial lag in the PAA death rates that was directly dependent on the temperature. BPL did not show this lag time.
Comparative Effects of Chlortetracycline, Freezing, and γ Radiation on Microbial Population of Ocean Perch
Authors: Lee J. S. , Willett Crystal L. , Robison Sarah M. , Sinnhuber R. O.
Published: December 2020

The microbial populations in chlortetracycline (CTC)-treated (50, 100, 200, and 500 ppm), frozen (-15 C), and irradiated (0.1 Mrad) ocean perch (
Sebastodes alutus
) were compared. The control sample spoiled at 7 C, primarily because of the growth of
Pseudomonas
. Irradiation changed this to
Achromobacter
-dominated spoilage. Freezing or CTC treatment altered the spoilage pattern very little. CTC was particularly effective against ultraviolet fluorescent
Pseudomonas
species at the higher concentrations. Freezing and CTC were not effective against “coryneforms.”
Laboratory Design for Microbiological Safety
Authors: Phillips G. Briggs , Runkle Robert S.
Published: December 2020

Of the large amount of funds spent each year in this country on construction and remodeling of biomedical research facilities, a significant portion is directed to laboratories handling infectious microorganisms. This paper is intended for the scientific administrators, architects, and engineers concerned with the design of new microbiological facilities. It develops and explains the concept of primary and secondary barriers for the containment of microorganisms. The basic objectives of a microbiological research laboratory, (i) protection of the experimenter and staff, (ii) protection of the surrounding community, and (iii) maintenance of experimental validity, are defined. In the design of a new infectious-disease research laboratory, early identification should be made of the five functional zones of the facility and their relation to each other. The following five zones and design criteria applicable to each are discussed: clean and transition, research area, animal holding and research area, laboratory support, engineering support. The magnitude of equipment and design criteria which are necessary to integrate these five zones into an efficient and safe facility are delineated.
Effect of Staphylococcal Enterotoxin B on the Electroencephalogram of Monkeys
Authors: Hodoval Leland F. , Morris Earl L. , Elsberry Dennis D. , Beisel William R.
Published: December 2020

A highly purified preparation of staphylococcal enterotoxin B was administered intravenously, 1 mg/kg, to rhesus monkeys. Electroencephalograms (EEG) were recorded from electrodes attached to the skin or implanted on the dura. The dose of toxin employed consistently produced a sequence of vascular collapse followed by death; in control studies, animals were bled periodically to produce a similar pattern of shock. Regardless of the time to death following administration of the enterotoxin, there were essentially no changes from base line EEG patterns until shortly before death. With the development of preterminal severe shock, there was a marked decrease in EEG wave frequency and an initial increase in amplitude. The latter diminished progressively to produce an isoelectric tracing immediately prior to death. This could be reversed for a brief period by epinephrine. An identical sequence of EEG changes was observed during the terminal period of hemorrhagic shock. It is postulated that cerebral anoxia, caused by inadequate blood flow, is the primary cause of the altered EEG patterns that accompany enterotoxin toxicity. In this respect, staphylococcal enterotoxin B produces changes apparently similar to bacterial endotoxin but distinctly different from the EEG effects reported after botulinum toxin, anthrax toxin, or rattlesnake and cobra venom.
Some Aspects of Thermal Injury in
Escherichia coli
Authors: Russell A. D. , Harries Diann
Published: December 2020

The effects of different temperatures on the viability of, and leakage of 260 mμ-absorbing substances from, a strain of
Escherichia coli
have been studied. Results of experiments with suspensions stored in water and in 0.33
m
sucrose, together with total counts of suspensions before and after heating, suggested that the initial damage inflicted on the cell was to the permeability barrier. However, it was concluded that the evidence presently available for supporting this hypothesis is inadequate.
Release of Inorganic Phosphate from Irradiated Yeast: Radiation Biodosimetry and Evaluation of Radioprotective Compounds
Authors: Levinson Hillel S. , Garber Esther B.
Published: December 2020

When cells of bakers' yeast,
Saccharomyces cerevisiae
, were irradiated with ionizing radiation, inorganic phosphate, ninhydrin-reactive material, and substances absorbing at 260 mμ were released into the suspending medium. The amount of inorganic phosphate released depended on the radiation dose and on the temperature and
p
H during irradiation. The concentration of yeast cells did not affect the phosphate yield per milligram of yeast. It is suggested that the release of phosphate may serve as an index of the total radiation environment (i.e., as a biodosimeter) where radiation inactivation of microrganisms is of primary importance, e.g., in radiation preservation of foods. The somewhat limited range of the yeast biodosimeter (ca. 0.5 to 1.75 Mrad) may be extended by use of other more resistant microorganisms, such as bacterial spores. Compounds which have been reported as protecting microorganisms and mammals against the lethal effect of ionizing radiation also inhibited the radiation-induced release of inorganic phosphate from yeast. This phosphate release system is proposed as the basis for an economical, rapid supplement to screening procedures in the evaluation of radioprotective compounds.
Independent Measurement of Ampicillin and Cloxacillin in Mixtures
Authors: Sabath Leon D. , Estey Valerie J. , Finland Maxwell
Published: December 2020

A simplified method of assaying mixtures of ampicillin and cloxacillin is presented. The method consists of cylinder-plate assays of appropriately diluted samples in three assay systems in which: (i) cloxacillin is measured, utilizing agar seeded with a penicillinase-producing
Staphylococcus aureus
; (ii) ampicillin is measured after the greatest dilution practicable, by use of agar seeded with
Sarcina lutea
; and (iii) the proportion of activity found in the second assay that remains after treatment with staphylococcal penicillinase is determined on agar seeded with
S. lutea
. The error was 4% or less when each system was run in quadruplicate, except when there was 10 or more times as much cloxacillin as ampicillin, in which case the greatest error was 12%. Mixtures of methicillin with benzylpenicillin or with ampicillin can also be quantitated by this method.
Characterization of Purified Staphylococcal Lipase
Authors: Vadehra D. V. , Harmon L. G.
Published: December 2020

Purified staphylococcal lipase had an optimal
p
H of 8.3 for activity at 37 C, and an optimal temperature of 45 C at
p
H 8.0. During storage, the enzyme lost less than 10% of the activity over a period of 21 days at 4 and -23 C. The enzyme retained 93% of the activity when heated for 30 min at 50 C and was 95% destroyed in 30 min at 70 C. The purified lipase was capable of hydrolyzing a variety of natural fats and oils. However, the enzyme was three times more active on nonhydrogenated soybean oil than on hydrogenated soybean oil with an iodine value of <3.0. The enzyme was also capable of hydrolyzing fatty acids on the α, β, and α′ positions of a synthetic mixed triglyceride. In general, the presence of oxidizing agents increased the activity and the presence of reducing agents decreased the activity of the lipase enzyme.
Production of Isoamylase by
Escherichia intermedia
Authors: Ueda Seinosuke , Nanri Nobuya
Published: December 2020

A culture of a coliform bacteria isolated from soil produced isoamylase when grown in peptone-maltose-salts broth. The enzyme preparation was partially purified. Its similarity with isoamylase produced by
Aerobacter aerogenes
was established by studying its action upon various polysaccharides. A study of the organism producing isoamylase showed that it differed from
A. aerogenes
in some of its physiological properties. This organism was identified as
Escherichia intermedia
from morphological and cultural characteristics.
Estrogenic Metabolite Produced by
Fusarium graminearum
in Stored Corn
Authors: Mirocha C. J. , Christensen C. M. , Nelson G. H.
Published: December 2020

A derivative of resorcinylic acid, produced by the fungus
Fusarium graminearum
, has been found to be responsible for the estrogenic signs in swine and laboratory rats. An estrogenic response in rats can be incited by injecting intramuscularly as little as 20 μg of the estrogen (F-2). Stimulation in growth of rats was noted at the lower concentrations (20 to 40 μg) of a series. Up to 3,500 ppm of the estrogen was produced on a solid corn medium. The compound is relatively stable to heat and ultraviolet irradiation. Methods of analysis have been developed and include: extraction procedures, evaluations by ultraviolet absorption spectrophotometry, thin-layer chromatography, and gas-liquid chromatography.
Selection of Microbial Population in Chlortetracycline-treated Ocean Perch (
Sebastodes alutus
)
Authors: Lee J. S. , Sinnhuber R. O.
Published: December 2020

Microorganisms isolated from chlortetracycline (CTC)-treated ocean perch were individually tested to determine their relative sensitivity to CTC by use of CTC-impregnated paper discs. The CTC sensitivity varied among isolates obtained from untreated fish. The proportion of CTC-resistant species increased with higher CTC concentration and the length of storage at 7 C. Among individual generic groups, “coryneforms” and yeasts were more resistant to CTC than other groups.
Pseudomonas, Achromobacter, Flavobacterium, Bacillus
, and
Lactobacillus
all contained species either resistant or sensitive to CTC. More CTC-resistant species in these genera accumulated with the increased CTC concentrations and with the length of storage in the presence of CTC.
Effects of a High Magnetic Field at Different Osmotic Pressures and Temperatures on Multiplication of
Saccharomyces cerevisiae
Authors: Van Nostran F. E. , Reynolds R. J. , Hedrick H. G.
Published: December 2020

The application of a yeast as a biosystem for determining the effects of a high magnetic field and other physical phenomena was studied. Multiplication of
Saccharomyces cerevisiae
was observed during exposure to a magnetic field of 4,600 gauss. Cell populations were determined at 24-, 48-, and 72-hr intervals, and possible interactions between the magnetic field and other environmental parameters, such as time, temperature, and osmotic pressure, were considered statistically. The main effect of the high magnetic field was a significant reduction of cell multiplication during each time interval. Significant interactions were found to occur between temperature and the magnetic field at 24 hr, and between temperature and osmotic pressure at each sampling interval. Synergistic effects of the magnetic field and osmotic pressure at both 28 and 38 C were nonsignificant.
Activity of Selected Penicillins In Vitro and in Experimental Bacterial Infections in Mice
Authors: Miraglia Gennaro J. , Basch Harold I.
Published: December 2020

The minimal inhibitory concentration and the 50% mouse protective dose for five key penicillins are presented. Such data provide a useful guide in evaluating the activity of new penicillins, in comparison with those already commercially available, and establishes the amounts of antibiotic necessary to obtain a PD
50
for several experimental model infections in mice.
Dechlorination of 1,1,1-Trichloro-2,2-bis(
p
-chlorophenyl)ethane by
Aerobacter aerogenes
Authors: Wedemeyer Gary
Published: December 2020

Whole cells or cell-free extracts of
Aerobacter aerogenes
catalyze the degradation of 1,1,1-trichloro-2,2-bis(
p
-chlorophenyl)ethane (DDT) in vitro to at least seven metabolites: 1,1-dichloro-2,2-bis(
p
-chlorophenyl)ethylene (DDE); 1,1-dichloro-2,2-bis(
p
-chlorophenyl)ethane (DDD); 1-chloro-2,2-bis(
p
-chlorophenyl)ethylene (DDMU); 1-chloro-2,2-bis(
p
-chlorophenyl)ethane (DDMS); unsym-bis(
p
-chlorophenyl)ethylene (DDNU); 2,2-bis(
p
-chlorophenyl)acetate (DDA); and 4,4′-dichlorobenzophenone (DBP). The use of metabolic inhibitors together with
p
H and temperature studies indicated that discrete enzymes are involved. By use of the technique of sequential analysis, the metabolic pathway was shown to be: DDT → DDD →DDMU →DDMS → DDNU → DDA → DBP, or DDT → DDE. Dechlorination was marginally enhanced by light-activated flavin mononucleotide.
Enhanced Toxicity for Mice of Pertussis Vaccines When Preserved with Merthiolate
Authors: Nelson E. A. , Gottshall R. Y.
Published: December 2020

Pertussis vaccines preserved with 0.01% Merthiolate are more toxic for mice than unpreserved vaccines prepared from the same parent concentrate and containing the same number of organisms. The toxicities of both Merthiolate (0.01%)-preserved and unpreserved vaccines increased when the number of organisms injected was increased. An increase in mortality was observed when Merthiolate was injected separately, before or after an unpreserved saline suspension of pertussis vaccine.
Preparative Procedure for the Purification of Toxoids by Gel Filtration
Authors: Latham William C. , Michelsen Christopher B. , Edsall Geoffrey
Published: December 2020

Sephadex gel filtration can be employed as a preparative procedure for the purification of both tetanus and diphtheria toxoids. A toxoid purification sequence is described in the text. By utilizing the described methods and columns, up to 100,000 human doses of diphtheria toxoid could be processed in a single operation. The method has given an 80% yield of diphtheria toxoid with a purity of 1,900 Lf per mg of N. The analysis of the material by immunodiffusion tests showed that a marked increase in purity was achieved. Antigenicity tests demonstrated that there was no significant difference in antigenic potency between the parent toxoid and its purified fraction. Factors limiting the effective separation of tetanus toxoid by gel filtration are discussed. The construction of the columns used is described in detail, as well as packing procedures and column characteristics such as bed volume, void volume, sample size, and flow rate.
Salmonella infantis
in Cattle Feedlot Runoff
Authors: Miner J. R. , Fina L. R. , Piatt Cheryl
Published: December 2020

Ten isolates of
Salmonella infantis
(serologically typed) were found in litter and runoff collected from two experimental feedlots near the Kansas State University campus. Pathogenic implications are discussed relative to recreation water sites. Agricultural runoff maybe a source of viable salmonellae.
Morphological Spore Types in the
Streptomyces hygroscopicus
-like Complex
Authors: Tresner H. D. , Backus E. J. , Hayes Jean A.
Published: December 2020

Streptomycetes comprising the
Streptomyces hygroscopicus
-like complex may be divided into two groups based on the micromorphology of their spores. The species
S. hygroscopicus
has short-cylindrical, phalangiform spores, whereas members of the second group possess elliptical-type spores. It was determined that
S. platensis
, of the latter group, is not only readily distinguishable from
S. hygroscopicus
on the basis of spore micromorphology, but differs, as well, according to various physiological measurements.
Thermal Inactivation Characteristics of Bacterial Spores at Ultrahigh Temperatures
Authors: Busta F. F.
Published: December 2020

The thermal inactivation characteristics of
Bacillus stearothermophilus
(1518) spores and putrefactive anaerobe (PA) 3679 (NCA) spores suspended in skim milk were determined after treatment in pilot-plant ultrahigh-temperature (UHT) processing equipment. Temperature-survivor curves were constructed from survival data to emphasize the critical nature of temperature control in process evaluation. Time-survivor curves for PA 3679 spores were concave upward, and decimal reduction time (DRT) curves for these spores supported the observation of a protective response occurring at the longest exposure times. However, exposure time did not markedly affect the extremely high
z
D
value obtained for PA 3679 spores. The substitution of Gelysate for Trypticase and Thiotone as the peptone in the sporulation medium increased the relative heat resistance of
B. stearothermophilus
spores, but lowered the
z
D
value from 16 F to 12 F. The DRT curves in all cases were linear, but the
z
D
values observed in this study differed considerably from those reported by other workers.
Computer Simulation of Fermentation Systems
Authors: Koga S. , Burg C. R. , Humphrey A. E.
Published: December 2020

Results of batch fermentation of gluconic acid by
Pseudomonas ovalis
were graphically analyzed to obtain a kinetic model to represent the data. Since gluconic acid was produced by the hydrolysis of a lactone intermediate, the model was necessarily represented by a set of kinetic equations. A computer simulation technique involving the use of the MIDAS program was developed to solve the system of nonlinear equations and to check the appropriateness of the model. Since the maximal specific growth rate and the rate constant for the production of the lactone intermediate varied with time, function generators were used to simulate these system parameters. The merit of using the MIDAS program was considered in relation to analysis and model testing in microbiological processes of similar types.
Degradation of Hydrocarbons by Members of the Genus
Candida
Authors: Klug M. J. , Markovetz A. J.
Published: December 2020

A representative number of species of the genus
Candida
were tested for their ability to utilize
n
-alkanes of 9 to 18 carbon atoms and even-numbered 1-alkenes of 10 to 18 carbon atoms. A high percentage of these organisms exhibited the ability to assimilate some member of the hydrocarbon series employed. These findings indicate that the ability to assimilate hydrocarbons is not limited to a few species of the genus and may be of some taxonomic significance.
Application of Paper Chromatograms to the Study of Inducers of λ Bacteriophage in
Escherichia coli
Authors: Heinemann Bernard , Howard Alma J. , Hollister Z. Jean
Published: December 2020

A procedure has been developed whereby paper chromatograms of agents which induce λ bacteriophage in
Escherichia coli
can be developed using bioautographs with a lysogenic test system. Well-defined plaque-forming zones are produced indicating the area on the paper chromatogram where the active inducing material can be located. A mixture of the bacteriophage-inducing antibiotic, mitomycin C, and the noninducing antibiotic, paromomycin, was resolved into its components on paper strips with an ethyl acetate-methanol solvent system. The location of both antibiotics could thus be readily observed. Antibacterial and inducing activities were found to be identical with a crude fermentation solid, NSC-B-158,791. The use of this procedure for resolution of multicomponent inducing activities in antibiotic beers and for characterization of active components which may be potential antitumor antibiotics is indicated.
Utilization of Carbon- and Nitrogen-containing Compounds for Neomycin Production by
Streptomyces fradiae
Authors: Majumdar Mrinal K. , Majumdar S. K.
Published: December 2020

A number of carbon and nitrogen compounds were tested for their effect on growth of
Streptomyces fradiae
3535 and neomycin production. Dextrin, starch, and maltose were excellent carbon sources for neomycin production, and sodium nitrate, aspartic acid, and glutamic acid were adequate nitrogen sources. Studies on biochemical changes during fermentation in four typical media indicated that there was no direct relation between the growth of the organism and neomycin formation. The
p
H of the medium might be an important factor for neomycin synthesis. The quantitative formation of neomycin components depended on the variation of carbon and nitrogen sources. On the basis of this study, a suitable synthetic medium for neomycin production has been developed.
In Vitro Antibacterial Activity of Kasugamycin
Authors: Levitan Alexander A.
Published: December 2020

Kasugamycin is an aminoglycosidic antibiotic which was initially reported as being of potential use against
Pseudomonas
. Our evaluation of this antibiotic does not confirm this expectation. The median minimal inhibitory concentration (MIC) of the
Pseudomonas
strains tested was 250 μg/ml and the bactericidal level was 500 μg/ml. Kasugamycin was found to be slightly more active in a more basic medium (Mycin Assay broth) in which the median MIC for 11
Pseudomonas
strains was 125 μg/ml. Kasugamycin manifests a modest degree of serum binding. Kasugamycin did not have any appreciable effect against a variety of bacteria tested. The only exceptions were several species of gram-negative bacteria, against which more satisfactory antibiotics already exist. Further evaluation of kasugamycin for potential human use as an antipseudomonal agent does not appear warranted.
Evaluation of T3 Coliphage Injuries and Efficacy of Selected Materials in Preventing Them
Authors: Walwick E. R. , Brady J. T. , Kay R. E.
Published: December 2020

A procedure was developed to analyze the inactivation of coliphage T3 during freeze-drying and subsequent rehydration. The amount of gross disruption of the phage as compared with the amount of phage remaining intact was evaluated by cesium chloride density gradient centrifugation. The amount of phage material able to adsorb to host cells and the residual infectivity after the drying were also evaluated. These analyses made it possible to determine the amount of phage material (i) degraded to protein and nucleic acid, (ii) intact or largely intact, (iii) capable of adsorption on host cells, and (iv) infective. The capacities of casein hydrolysate, ascorbic acid, thiourea, bovine albumin, polyethyleneglycol, raffinose, inositol, and lipoproteins to protect T3 bacteriophage from the stress of freeze-drying were investigated.
Sporulation of the “Thermophilic Anaerobes.”
Authors: Pheil Charles G. , Ordal Z. John
Published: December 2020

A reasonable degree of synchrony in the sporulation of
Clostridium thermosaccharolyticum
3814 was obtained by using three 10% transfers of 8-hr cultures in a medium containing 0.5% L-arabinose, 0.5% peptone, 0.5% yeast extract, and Gc minerals. Sporulation was stimulated by L-arabinose and L-xylose, but was repressed by glucose, mannose, fructose, and D-pentoses. Sporulating cells were long and thin, whereas repressed cells were shorter and thicker. The optimal
p
H for sporulation was in the range of
p
H 5.0 to 5.5. As sporulation continued, the accumulated acetate decreased. Label studies indicated that a significant amount of acetate-
2
-
C
14
was incorporated into the spore lipid. The calcium, phosphorus, and dipicolinic acid (DPA) concentrations on a dry weight basis were 2.55, 2.60, and 7.25%, respectively. The molar ratio of Ca-DPA was 1.47.
Microbiological Laboratory Hazard of Bearded Men
Authors: Barbeito Manuel S. , Mathews Charles T. , Taylor Larry A.
Published: December 2020

An investigation was conducted to evaluate the hypothesis that a bearded man subjects his family and friends to risk of infection if his beard is contaminated by infectious microorganisms while he is working in a microbiological laboratory. Bearded and unbearded men were tested with
Serratia marcescens
and
Bacillus subtilis
var.
niger
. Contact aerosol transmission from a contaminated beard on a mannequin to a suitable host was evaluated with both Newcastle disease virus and
Clostridium botulinum
toxin, type A. The experiments showed that beards retained microorganisms and toxin despite washing with soap and water. Although washing reduced the amount of virus or toxin, a sufficient amount remained to produce disease upon contact with a suitable host.
Antibiotic Production of Hyphal Fractions of
Streptomyces griseus
Authors: Szesz�k F. , Szab� G.
Published: December 2020

The streptomycin-producing activity (SPA) of hyphal fractions from washed mycelium of submerged cultures of
Streptomyces griseus
strain 52-1, as obtained by density gradient centrifugation, was investigated. Activity of the various fractions differed strongly in intensity. The highest SPA was evident in the unfractionated mycelium. A synergistic effect upon SPA was found in the interaction of cultures of different ages, and a 55% increase in yield was obtained by mixing the 48- and 72-hr cultures. A synergistic effect occurred in all combinations studied. By use of fractions obtained from 72-hr mycelium for inoculation, differences in streptomycin production were noted. Some inoculum fractions yielded a greater amount of streptomycin (36%) than the unfractionated mycelial inoculum.
Adsorption of Staphylococcal Bacteriophage by Milk Proteins
Authors: Das N. K. , Marshall R. T.
Published: December 2020

Propagation of homologous bacteriophage in a culture of
Staphylococcus aureus
(1:1 ratio of phage to bacteria) in Trypticase Soy Broth (TSB) and in skim milk indicated more activity of phage in TSB. Early lysis of bacteria in skim milk followed by a pronounced rise in bacterial population suggested that staphylococcal phages were being inactivated by milk. Titration of phages from skim milk, whey, and TSB indicated about 90% adsorption of phages by acid- and heat-precipitable proteins of skim milk, whereas numbers recovered from whey were quite comparable to those recovered from TSB. Reducing the
p
H from 6.5 to 4.0 increased the percentage of phages recoverable from skim milk from 10 to 56%. Apparently, the changes in electrical charges on the casein micelles at this low
p
H were responsible for release of many phages from their complex with casein.