bluuebunny/crossref_metadata_2025 huggingface dataset:
Enzyme Patterns in the Study of
Leptospira
Authors: Green Stanley S. , Goldberg Herbert S. , Blenden D. C.
Published: December 2020

An analysis of intracellular and extracellular leptospiral enzymes was made by use of starch-gel electrophoresis with natural and synthetic substrates. Of 37 serotypes examined for extracellular exterase, all had activity of varying mobility and degree. All extracellular preparations were negative for catalase, phosphatase, and naphthylamidase. Intracellularly, five serotypes were examined, including
Leptospira biflexa
Patoc I,
L. biflexa
Waz,
L. canicola
Moulton,
L. icterohaemorrhagiae
RGA, and
L. pomona
S91. Among the enzymes detected by this electrophoretic technique were transaminase and catalase, confirming the results of previous investigators. Further, other enzymes heretofore unreported have been detected. These include esterases, phosphatases, lactic, malic, glutamic, succinic, α-glycerophosphate, and 6-phosphogluconic dehydrogenases, and a naphthylamidase. The presence of these enzymes suggests the existence of tricarboxylic acid, glycolytic, and pentose-related pathways in
Leptospira
. In addition, enzyme patterns show promise in leptospiral classification.

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Two Quick Methods for Voges-Proskauer Test
Authors: Barry A. L. , Feeney K. L.
Published: December 2020

Two previously described methods for rapidly performing a Voges-Proskauer (VP) test were modified so that results could be obtained even more quickly. On MacConkey agar, colonies of lactose-fermenting, VP-positive organisms usually contain enough acetoin to give a positive reaction when a dense suspension is prepared in creatine and tested directly with Barritt reagents. With this direct-screening test, no “false” positive results were seen, but 29 of 429 lactose-fermenting strains of
Enterobacteriaceae
initially gave “false” negative results. Thus, another technique was needed for quickly confirming negative results. A 0.2-ml amount of MR-VP Broth culture, inoculated with one colony or less, can be tested after 4 to 6 hr at 37 C by adding two drops of a 0.5% creatine solution followed by Barritt reagents. No “false” positive results were seen with 508 cultures, but one atypical coliform bacillus was negative with this method and VP positive after 48 hr of incubation in MR-VP Broth. With these two quick methods, the common VP positive organisms can be recognized within a few minutes or at most after a few hours.
Copper Sulfate-induced Fermentation Changes in Continuous Cultures of the Rumen Microbial Ecosystem
Authors: Slyter L. L. , Wolin M. J.
Published: December 2020

The effect of CuSO
4
on fermentation was studied in a continuously cultured rumen ecosystem. CuSO
4
, introduced at a level of 50 mg/500 ml of culture volume twice daily, caused a marked inhibition of fermentation of concentrates. Fermentation of alfalfa hay was not inhibited by the same CuSO
4
concentration when the inoculum for the culture was obtained from a cow maintained on a normal concentrate ration. When the inoculum was from a cow on a high concentrate ration, hay fermentation was partially inhibited by CuSO
4
. Concentrations of CuSO
4
that did not inhibit the fermentation of alfalfa hay or hay-concentrate mixtures caused preferential production of propionic acid and decreased production of methane.
Laboratory Examination of Organic Fungicides Against Zoopathogenic Fungi in Soil
Authors: Morehart Allen L. , Larsh Howard W.
Published: December 2020

Seven commercial and five experimental organic fungicides were tested against
Histoplasma capsulatum, Cryptococcus neoformans, Allescheria boydii
, and
Sporotrichum schenckii
in a series of laboratory studies. Preliminary agar dilution plate tests indicated that Lanstan, DAC 649, DAC 469, DAC 2787, He 3944, maneb, and nabam, in order of decreasing activity, inhibited all test fungi. Terraclor, Dexon, and He 13274 were active only in high concentration. The best fungicidal properties were exhibited by Lanstan, Vapam, and DAC 649; maneb, nabam, DAC 469, and DAC 2787 were fungicidal but to a lesser degree than the former compounds. In subsequent tests against
H. capsulatum
and
C. neoformans
in artificially infested soil or by use of the buried plug technique, Lanstan, Vapam, and DAC 649 showed good activity and merit further study.
Synergistic Effects in Sonochemical Sterilization
Authors: Boucher Raymond M. G. , Pisano Michael A. , Tortora George , Sawicki Edward
Published: December 2020

The synergistic effects observed during the sterilization of
Bacillus subtilis
var.
niger
ATCC 9372 by the combined action of ethylene or propylene oxide with high-intensity airborne sound waves (34.8 kc/sec) were investigated. It has been shown that the number of surviving spores deposited on paper strips decreases exponentially with the sound intensity at sample level. Reductions of the order of one-third of the time required for standard propylene oxide sterilization have been observed by using the combined action of sound waves with gaseous sterilization. At the present time, maximal synergistic effects seem to be achieved for the following experimental conditions: propylene oxide concentration, 500 to 1,000 mg/liter; acoustic intensity, 161 to 162 db; contact time, 80 min; temperature, 60 C; and relative humidity, 40%. The basic mechanism involved in sonochemical sterilization seems to be more of a physical (accelerated gas diffusion) than a chemical nature.
Production of Lysergic Acid Derivatives in Submerged Culture
Authors: Rosazza John P. , Kelleher William J. , Schwarting Arthur E.
Published: December 2020

The inorganic requirements for growth and alkaloid production by submerged cultures of a lysergic acid alkaloid-producing isolate of
Claviceps paspali
were determined in a defined medium. The requirement for peak growth was essentially the same as the requirement for maximal alkaloid production in the case of potassium and magnesium. With phosphorus, however, maximal growth was reached at lower levels than those required for maximal alkaloid production. Sulfur was required in smaller amounts for peak alkaloid production than for maximal growth. In the case of iron and zinc, the requirement for maximal alkaloid production was greater than for growth. Manganese and copper could be sufficiently depleted to demonstrate their essentiality for alkaloid production, but their requirements for growth could not be demonstrated.
Conditions Influencing the Synthesis of Acid Protease by
Mucor pusillus
Lindt
Authors: Somkuti G. A. , Babel F. J.
Published: December 2020

Protease synthesis by
Mucor pusillus
Lindt, in a wheat bran medium under submerged conditions, was influenced by substrate concentration, initial
p
H of the medium, and temperature of incubation. A 4% wheat bran (dry weight) concentration was satisfactory for enzyme production. The initial
p
H of the medium had a substantial effect on enzyme synthesis; adjustment of the enzyme production medium to
p
H 5.0 prior to sterilization was desirable. Incubation at 35 C resulted in the best enzyme yields. Under optimal conditions of enzyme production, maximal activity was detected after 5 days of incubation. The enrichment of the medium with glucose increased the yield of mycelia but lowered the amount of enzyme produced.
Chemical Composition of Variants of Aerobic Actinomycetes
Authors: Šuput Jelena , Lechevalier Mary P. , Lechevalier H. A.
Published: December 2020

It has been shown previously that aerobic actinomycetes can be separated into four main groups on the basis of their cell wall composition. Six representatives of aerobic actinomycetes (
Nocardia asteroides
and
Micropolyspora brevicatena
, cell wall type IV;
N. madurae, Microbispora rosea
, cell wall type III;
Actinoplanes
sp., cell wall type II;
Streptomyces griseus
, cell wall type I) were subjected to selecting agents which permitted the isolation of stable variants morphologically different from the parent strain. Whole cell analyses of 134 substrains from the six parents revealed no significant change in the isomeric form of diaminopimelic acid or in sugar constituents. Analyses of cell wall preparations from 52 of these did not reveal any change in the diagnostic constituents of their murein or polysaccharides.
Antimicrobial Performance of Tri- and Tetrachloro-4-(Methylsulfonyl) Pyridines as Industrial Preservatives
Authors: Wolf Paul A. , Bobalek F. J.
Published: December 2020

Tests show that trichloro- and tetrachloro-4-(methylsulfonyl) pyridines have a wide spectrum of activity against microorganisms causing deterioration in industrial systems. They are particularly active as fungistats and are more effective against gram-positive than against gram-negative bacteria. Their fungistatic activity and persistence have led to outstanding performance as mildewcides in exterior paints. In addition, we report the performance of these compounds as preservatives in the following products: asphalt, calking compositions, joint cements, paper, plastics, soluble oils (cutting fluid emulsions), and textiles.
Serological Identification of Enterotoxigenic Staphylococci from Cheese
Authors: Donnelly C. B. , Leslie J. E. , Black L. A. , Lewis K. H.
Published: December 2020

Single and double gel-diffusion techniques were employed to examine serologically coagulase-positive staphylococci from cheese for enterotoxigenicity. Supernatant fluid from sac cultures was examined for enterotoxins A and B. The results indicated that 9 of 155 cultures from market cheese and 7 of 77 cultures from food-poisoning cheese produced enterotoxin A, and that none of the cultures produced detectable levels of enterotoxin B. Results of serological tests were confirmed by intravenous injection of cats.
Protozoan, Bacterial, and Volatile Fatty Acid Changes Associated with Feeding Tylosin
Authors: Satapathy N. , Purser D. B.
Published: December 2020

Tylosin was fed to two of six wethers for 79 days, to a second two for only 28 days, and not at all to a third pair (controls). The addition of tylosin to the daily feed resulted in a rapid twofold increase in protozoal concentration and a change in the composition or characteristics, or both, of the bacterial population. The results indicate that the bacterial population was modified to the extent of about 80%. Total acid concentrations were initially depressed but appeared to be greater than those in control animals at the termination of the experiment. Deletion of tylosin from the ration resulted in a rapid decrease in protozoal concentrations, whereas changes in the bacterial population did not occur for a further 30 days.
Degradation of Glucose by Proliferating Cells of
Desulfotomaculum nigrificans
Authors: Akagi J. M. , Jackson Gloria
Published: December 2020

Desulfotomaculum nigrificans
degraded glucose to acetate, ethyl alcohol, and carbon dioxide. By use of
14
C-glucose labeled at different carbon atoms, two pathways of glucose metabolism were detected. They were the Embden-Meyerhof and the Entner-Doudoroff schemes. Because the observed quantities of acetate and carbon dioxide, arising from glucose, were greater than the expected theoretical values, individual fermentations were conducted with 15 uniformly labeled
14
C-amino acids. The results indicated that amino acids, supplied by the yeast extract or peptone in the fermentation medium, also contributed to the formation of acetate and carbon dioxide.
Comparison of Fluorescent Antibody with Cultural Technique for Isolation of Enteropathogenic
Escherichia coli
from Swine
Authors: Filippone M. V. , Mitchell I. A. , Brayton J. B. , Newell K. W. , Smith M. H. D.
Published: December 2020

In an investigation of hogs as possible reservoirs of human strains of enteropathogenic
Escherichia coli
(EEC), 92 six-month-old grain- and garbage-fed hogs were examined on the farm and again at the packing plant. Of the 331 specimens obtained by swabbing the rectum, cecum, and edible meat carcass of these hogs, 125 were presumptively positive for EEC when screened by the fluorescent-antibody (FA) technique. These “presumptive positive” specimens then underwent extensive bacteriological examination and complete serological typing. The FA technique proved to be an easier, simpler, and more economical procedure than culture when a large number of specimens were examined for possible EEC serogroups. It was found especially valuable for identification of multiple serogroups of EEC within a single specimen. It also appeared to be more sensitive than cultural examination, since results were not dependent on the presence of large numbers of organisms in the specimen, or even on their viability. However, the FA technique was found to be less specific than culture because of cross-reactivity with antigenically related
Enterobacteriaceae
when fluorescein-labeled antisera were used. Therefore, any specimen found positive on FA examination should be considered as presumptive positive until confirmed by bacteriological examination and complete serological study.
Control of Pleuropneumonia-like Organisms in Cell Culture
Authors: Buskirk Harold H.
Published: December 2020

Mammalian cell culture systems were maintained free of mycoplasmas by using a 3-day agar plate test as a weekly routine to monitor the conditions of the cells. If contaminated cell cultures were found, they were discarded and replaced from a pleuropneumonia-like organism (PPLO)-free cell bank. PPLO-free lines were established by treatment with various antibiotics. The KB cell line was freed of mycoplasmas by treatment for 1 week with a mixture of chlortetracycline, kanamycin, and chloramphenicol. L-929 cells were cleared of contamination with either spectinomycin or tylosin, and a synovial cell line was cleared with lincomycin or tylosin. Each cell line, after eradication of the contaminant, was stored in liquid nitrogen. A number of agents were tested to determine minimal inhibitory concentration against three known and three unidentified mycoplasmas. Chlortetracycline and tetracycline were found to be highly active against all strains, whereas tylosin, spectinomycin, and lincomycin, though less active, were equally useful because of their low toxicity against cells. Kanamycin was highly active against three strains, but inactive at high levels against the KB cell contaminants. A disc plate test was used to check isolated cell contaminants for sensitivity to various agents.
Growth of
Salmonella
in Chickens' Yolk Sacs and Its Relationship to Pathogenicity
Authors: Stephens J. F. , Anderson E. L.
Published: December 2020

Newly hatched chicks were inoculated in the yolk sacs with standardized suspensions of
Salmonella anatum, S. heidelberg
, or
S. infantis
. At intervals between 3 and 48 hr postinoculation, chicks from each group were sacrificed, the average number of viable cells per yolk sac was determined, and liver tissue from each chick was examined for
Salmonella
. Growth patterns of the three species were almost identical when each chick was inoculated with about 3.5 million cells, but
S. heidelberg
was recovered more frequently from the liver, and caused a much higher percentage of mortality than did either
S. anatum
or
S. infantis
. When 100-fold dilutions of the suspension of
S. heidelberg
were used, mortality and recovery rates of the bacterium from the liver were directly related to the number of cells injected. The logarithmic growth phase was lengthened as the number of cells in the inocula was decreased; consequently, there was little difference in the average number of
S. heidelberg
cells per yolk sac at 36 or 48 hr postinoculation regardless of number of cells injected. Results of these trials indicated that factors other than rate of multiplication in the yolk sac are responsible for observed differences between
Salmonella
species in degree of pathogenicity for baby chicks.
Use of Immunofluorescence and Animal Tests to Detect Growth and Toxin Production by
Clostridium botulinum
Type E in Food
Authors: Midura T. , Taclindo C. , Nygaard G. S. , Bodily H. L. , Wood R. M.
Published: December 2020

The appearance of
Clostridium botulinum
type E organisms and of toxin in experimentally inoculated packages of turkey roll was followed to study the time relationship between the presence of vegetative cells and the demonstration of toxin. The presence of vegetative cells was determined by immunofluorescence, and animal tests were used to assay toxin production. Growth initiated from detoxified spores of
C. botulinum
type E resulted in toxin formation within 24 hr. Presence of fluorescing vegetative cells and of toxin coincided from 1 to 14 days of incubation. Beginning with the next testing date, day 21, differences were observed. Toxin could be detected for a longer time than vegetative cells. Neither toxin nor organisms could be found after 56 days of incubation. The mouse lethal dose tests (MLD per gram of turkey roll) showed fluctuations in the amount of toxin present throughout the period of testing. Maximal amounts of toxin were present during the period when fluorescing organisms were also more numerous. The applications of immunofluorescence in the study and in the diagnosis of botulism is discussed.
Use of a Fluorescent Brightener to Demonstrate Cellulose in the Cellular Slime Molds
Authors: Harrington Brian J. , Raper Kenneth B.
Published: December 2020

The presence and location of cellulose in different stages of the life cycles of the cellular slime molds can be demonstrated by use of the disodium salt of 4,4′-bis(4-anilino-6-bis (2-hydroxyethyl)-amino-s-triazin-2-ylamino)-2,2′ -stilbene disulfonic acid, a fluorescent brightener. It may be used successfully as a direct stain at a concentration of 0.1% in half-normal saline at
p
H 6; and it may be incorporated into growth media as a vital stain at a concentration of 0.0025% with no inhibitory effect at any developmental stage. Vegetative myxamoebae contain no cellulose and show no fluorescence in the presence of this brightener when viewed with ultraviolet light. In later stages of the life cycle, the time and sites of cellulose formation can be demonstrated with the brightener because of its fluorescence. e.g., in the slime covering of the pseudoplasmodia, in the sorophore sheath, in the walls of stalk cells and spores, in the walls of microcysts, and in the walls and sheath material of macrocysts. The brightener appears to be a very sensitive indicator for cellulose, and it has certain advantages over other cellulose stains, since the staining reaction (fluorescence) is very intense, long-lasting, and not obscured by unstained cellulose-free myxamoebae if such are present.
Quantitative Aspects of the M Protein Capillary Precipitin Test
Authors: Cohen Jay O. , Pine Leo
Published: December 2020

A capillary procedure for quantitatively determining M protein is described. Capillaries were filled with measured amounts of serum and streptococcal extract. The capillaries were incubated, and then centrifuged to pack the precipitates. The relative sizes of the precipates were compared by a determination of the weights of their paper images (obtained by reflection from a microscope). Meaningful dilution curves were determined by this method. Variations of
p
H from 6 to 8 had little effect on the M protein precipitin test, and the test was not seriously affected by variations of the NaCl concentration from 0.85 to 4.67%. The addition of divalent ions (Ca
++
and Mg
++
) did not influence the results. This test can be used to make quantitative comparisons of M protein preparations and to titrate type-specific antisera.
Metabolism of Some Anionic Tallow-based Detergents by Sewage Microorganisms
Authors: Cordon Theone C. , Maurer Elmer W. , Nuñez-Ponzoa M. V. , Stirton A. J.
Published: December 2020

A method in which the test detergent was the sole source of carbon was used to study the metabolism of several tallow-based detergents. These were tallow alcohol sulfates, long-chain ether alcohol sulfates, and esters of α-sulfo fatty acids. Sodium
p
-(1-methylundecyl)benzenesulfonate (LAS) was used as a reference material. The alcohol sulfates were the most rapidly and completely metabolized (96 to 99%), and one ether alcohol sulfate was 94% degraded. The other compounds were metabolized to the extent of 61 to 87%; LAS was 80% degraded. Except for the alcohol sulfates, loss of methylene blue activity (MBAS) occurred long before the chemical oxygen demand (COD) values had reached a minimum; with the alcohol sulfates, MBAS and COD decreased simultaneously.
Heat-stable Chemically Defined Medium for Growth of Animal Cells in Suspension
Authors: Nagle Stanley C.
Published: December 2020

Procedures are described for preparation of a chemically defined medium, capable of being autoclaved, for the cultivation of animal cells in suspension. Yields of 34.1 × 10
5
, 33.8 × 10
5
, and 47.1 × 10
5
cells per ml were recorded for cat kidney, HeLa, and mouse fibroblast (L) cells after 6, 10, and 10 days of incubation, respectively.
Production of Streptokinase in Continuous Culture
Authors: Holmström Björn
Published: December 2020

A method for continuous cultivation of a β-hemolytic streptococcus, strain H 64, is described. The production of cells and streptokinase at various dilution rates,
p
H, and temperature were studied in a complex medium supplied with excess glucose. At
p
H 7.0, productivity of cells and streptokinase, as well as the yield constant with respect to glucose, all increased with increasing dilution rate in the range of 0.1 to 0.5 hr
-1
. The production of streptokinase was found to be a function of both growth rate and cell concentration. Although higher concentrations of streptokinase were obtained in experiments with batch cultures, the production of streptokinase in continuous cultures was found to be 2.3 times higher. The possible industrial application of a continuous production method is considered.
Responses of Staphylococci to Androgens
Authors: Yotis William , Fitzgerald Thomas
Published: December 2020

The reported regulatory activities of hormones on mammalian cells suggest that a hormonal effect may be of importance in the host-parasite relationship of staphylococci. Male 6-month-old rabbits of similar genetic constitution were given subcutaneously 20 μg of androgens in saline containing 1% ethyl alcohol. Control rabbits received 1% ethyl alcohol in saline. At 5 to 10 min after administration of androgens, the rabbits were bled by cardiac puncture, and the serum was separated and incubated with standardized suspensions of
Staphylococcus aureus
serotypes I to XIII. It was found that
S. aureus
grew more luxuriantly in the sera of the control rabbits than in the sera of androgen-treated animals. With tryptic soy broth as a culture medium, a concentration 150- to 300-fold (30 to 40 μg/ml) higher than that achieved in the blood of an androgen-treated rabbit was required to yield an equivalent effect. In addition, the androgen-staphylococcal interaction has been studied with regard to experimentally induced furunculosis, the uptake of androgens by staphylococci and steroid molecular structure and antimicrobial activity. The data indicate that androgens may play a role in protection against staphylococcal infection.
Antifungal Properties of Cranberry Juice
Authors: Swartz Jacob H. , Medrek Theodore F.
Published: December 2020

Cranberry juice exerts a significant in vitro antifungal effect on eight representative species of dermatophytes, whereas it has no apparent effect on
Candida albicans
. The antifungal effect is fungistatic. Benzoic acid or other small molecular weight components, or both, were responsible for the fungistatic action. Studies with
C. albicans
on the effect of
p
H alone and the effect of
p
H on the ionization of benzoic acid indicate that cranberry juice would exert an even more significant antifungal action if the
p
H were left at its native value of 2.8; not adjusted to 5.6. This would probably be due to
p
H and a larger amount of free benzoic acid. Further investigation suggested that benzoic acid loses some of its antifungal properties in cranberry juice at
p
H 5.6. This investigation suggests that the dermatophytes may have a higher sensitivity to benzoic acid or other small molecular weight components of cranberry juice, or to both.
Identification of
Pseudomonas
Species Isolated from Hospital Environment and Human Sources
Authors: Sutter Vera L.
Published: December 2020

Methods and procedures are described for the identification of aerobic pseudomonads isolated from clinical specimens. Fluorescence is used as a means of primary differentiation. Final identification is based on the observation of characteristics such as flagellation, storage of intracellular fat, growth at 4 C and at 41 C, denitrification, gelatin hydrolysis, arginine dihydrolase activity, and oxidase activity. The value of this schema to the diagnostic laboratory is discussed.
Infectivity-destroying Effect of Humidity for Dried Coliphage T1
Authors: Lorenz P. R.
Published: December 2020

Infectivity of dried coliphage T1 has been measured as a function of humidity, temperature, and atmospheric pressure. Loss of infectivity by a factor of 10
4
was caused by water vapor of approximately 40 to 85% saturation when the microorganisms were kept for 3 days at 34 C in evacuated containers. At humidities below 40% and above 90% saturation, no loss of infectivity occurred. At a temperature of 24 C, the infectivity loss was 20-fold. When the virus preparation was kept at 34 C and atmospheric pressure, some loss of infectivity was also found at humidities below 40% and above 90% saturation. Damage to tail proteins or to the phage chromosome is considered as a possible explanation for the inactivation.
Activities of Arginine Dihydrolase and Phosphatase in
Streptococcus faecalis
and
Streptococcus faecium
Authors: Mackey Jesse K. , Beck Raymond W.
Published: December 2020

Strains of
Streptococcus faecalis
and
S. faecium
are known to produce ammonia from arginine, but only
S. faecalis
couples the adenosine triphosphate (ATP) produced through the arginine dihydrolase pathway to growth processes. The specific activities of the arginine dihydrolase enzymes were found to be much lower in
S. faecium
(0.01 to 0.10) than in
S. faecalis
(0.24 to 1.60). Phosphatase activities in both strains were similar (up to 0.11), but equaled or exceeded the activities of the arginine dihydrolase enzymes in
S. faecium
. The failure of
S. faecium
to show increased growth in arginine media is explained on the basis of low activities of the arginine dihydrolase enzymes coupled with sufficient phosphatase activity to negate any benefit from ATP formed.
Specificity of Penicillin Acylase of
Fusarium
and of
Penicillium chrysogenum
Authors: Vanderhaeghe H. , Claesen M. , Vlietinck A. , Parmentier G.
Published: December 2020

Extracts containing penicillin acylase were obtained by shaking the mycelium of
Fusarium avenaceum
and of
Penicillium chrysogenum
in 0.2 M sodium acetate or sodium chloride solution. The optimum
p
H for conversion of penicillin V into 6-aminopenicillanic acid (6-APA) by the enzyme of
Fusarium
was about 7.5, and the reaction velocity was increased by a rise in temperature from 27 to 37 C. Penicillin G and penicillins with an aliphatic side chain were cleaved much less readily than was penicillin V. With the enzyme preparation obtained from a nonpenicillin-producing strain of
P. chrysogenum
, the reaction rate was higher at
p
H 8.5 than at
p
H 7.5 and
p
H 6.5. The acylase of
P. chrysogenum
hydrolyzes penicillin V more readily than penicillin G. In a series of aliphatic penicillins, the amount of 6-APA formed through the action of this enzyme increased with the number of carbon atoms of the side chain. Penicillins with a glutaryl or an adipyl group as side chain were unaffected by the enzyme of
Fusarium
and of
Penicillium
. No reaction was observed upon incubation of penicillin N (with a D-aminoadipyl side chain) or isopenicillin N (with an L-aminoadipyl side chain) with
Fusarium
and
Penicillium
extract. When the carboxy group of the side chain of these penicillins was esterified, formation of 6-APA was observed upon incubation with
Penicillium
extract, whereas no 6-APA or only very small amounts were obtained by acylase of
Fusarium
.
Production of Reference Enteroviruses
Authors: Kalter S. S. , Rodriguez A. R. , Armour V.
Published: December 2020

Forty-five human enterovirus reagents of certified purity and quality were prepared for use as seed viruses and as immunizing antigens. One of the reagents was ampouled as “untreated” seed virus, whereas 14 were ampouled as “MgCl
2
-stabilized” reagents. The remaining 30 reagents were ampouled as “untreated” seed viruses and as “MgCl
2
-stabilized” reagents. Thirty of the reagents were propagated on primary African green monkey kidney cells, 3 on primary baboon kidney cells, 3 on primary rhesus monkey kidney cells, and the remaining 9 on human amnion cells. Forty-two of the viral antigens were concentrated for use in the production of high-titered specific antisera in large animals.
Characterization of Bacteria by Their Degradation of Amino Acids
Authors: Pickett M. J. , Pedersen M. M.
Published: December 2020

A procedure for detecting the degradation of amino acids by microorganisms is described, and examples of its use in the characterization of bacteria are presented. The procedure involves inoculating a buffered solution of amino acids with a suspension of bacteria, incubating, chromatographing a sample of the suspension, and detecting degradation in terms of absence of ninhydrin-positive spots.
Lactic Acid Bacterial Fermentation of
Burong Dalag
Authors: Orillo C. A. , Pederson C. S.
Published: December 2020

The fermented food,
burong dalag
, prepared in many Filipino homes, was studied to determine the nature of the microbiological and chemical changes that occur during fermentation. This is a lactic acid bacterial fermentation in which the species
Leuconostoc mesenteroides, Pediococcus cerevisiae
, and
Lactobacillus plantarum
played the major acid-producing role. The
p
H was lowered to below 4.0, and about 0.9% acid as lactic acid was attained in 1 week. It was essential to keep the product covered well to exclude air and subsequent growth of yeasts and mold.
Energy Utilization for Polysaccharide Synthesis by Mixed Rumen Organisms Fermenting Soluble Carbohydrates
Authors: Walker D. J.
Published: December 2020

Synthesis of reserve polysaccharide by mixed rumen organisms fermenting glucose, maltose, cellobiose, and xylose has been studied in relation to the adenosine triphosphate energy calculated to be available from substrate fermentation. About 80% of the energy available from glucose and xylose was used for polysaccharide synthesis, whereas, assuming hydrolytic cleavage of the disaccharides, more than 100% was used when cellobiose and maltose were the substrates. If, however, phosphorolytic cleavage of the disaccharides, for which there is evidence, was involved, the energy from both maltose and cellobiose fermentation was used with about the same efficiency as that from glucose and xylose fermentation. The rumen fluid used was collected 24 hr after feeding, and growth of microorganisms in such samples was sufficient to account for utilization of less than 10% of the total energy becoming available during the 40-min incubation period.
Detection of
Salmonella
by a Single-Culture Technique
Authors: Abrahamsson Kerstin , Patterson G. , Riemann H.
Published: December 2020

Dulcitol-selenite enrichment medium in a motility flask was used for the detection of
Salmonella
in food. A drop in
p
H of the dulcitol-selenite enrichment motility broth indicated the presence of
Salmonella;
this phenomenon was confirmed by fluorescent-antibody staining. A complete correlation was found between fluorescent-antibody staining and recovery on Brilliant Green agar. Testing of 332 samples of 8 different kinds of foods and feeds indicated no significant difference in sensitivity between the new technique and a conventional
Salmonella
detection technique. The new technique permitted detection of even small numbers of
Salmonella
in 1 to 2 days.
Quantitative Analysis of
Actinomyces
Cell Walls
Authors: DeWeese Martha S. , Gerencser Mary Ann , Slack John M.
Published: December 2020

Quantitative data on the amino acid composition of cell walls of five species of
Actinomyces
were obtained by using a Beckman-Spinco amino acid analyzer. The major amino acids in
A. israelii, A. naeslundii, A. eriksonii
, and
A. bovis
species included alanine, glutamic acid, lysine, aspartic acid, and ornithine, as reported by previous workers, whereas
A. propionicus
contained diaminopimelic acid. Other amino acids, including glycine, valine, leucine, proline, isoleucine, and threonine, were present in at least some of the walls in quantities equal to or slightly less than that of lysine. This raised the question of whether these may represent cross-links in the peptidoglycan or other cell wall structural components or whether the wall preparations contained nonpeptidoglycan material despite the use of electron microscopy as a standard of purity; further work is required to supply the answer. The quantitative data furnish relative molar concentrations of amino acids, which can provide definitive identification of some of the species and differentiation of
Actinomyces
from other members of the
Actinomycetales
and from morphologically similar genera such as
Corynebacterium
and
Propionibacterium
.
Milk-clotting Enzyme from Microorganisms
Authors: Arima Kei , Yu Juhyun , Iwasaki Shinjiro , Tamura Gakuzo
Published: December 2020

A rennin crystal was obtained from the crude milk-clotting enzyme of
Mucor pusillus
var.
Lindt.
The crude enzyme was purified by using columns of Amberlite CG-50, diethylaminoethyl Sephadex A-50, and Sephadex G-100. This purified enzyme was dissolved in 0.1 M sodium acetate (
p
H 5.0) buffer to a final concentration of 2 to 3%; ammonium sulfate (to 40% saturation) was added, and the resulting solution was placed in cellophane tubes. The enzyme solution was dialyzed against 0.1 M sodium acetate buffer (
p
H 5) containing ammonium sulfate was added dropwise to the outside solution of the cellophane tube, and the concentration of ammonium sulfate in the cellophane tube increased gradually. The crystals of enzyme were formed in the cellophane tube when the concentration reached approximately 50% saturation. After the enzyme solution was concentrated in the freezer, the crystals were obtained. The activity of the crystalline enzyme was inhibited by Hg
2+
, Ag
+
, Zn
2+
, and KMnO
4
.
Detection and Incidence of Specific Species of Spoilage Bacteria on Fish
Authors: Levin R. E.
Published: December 2020

The ability of
Pseudomonas putrefaciens
to form H
2
S was found to serve as a singularly useful criterion of identity for this species and was used to directly enumerate the organism from haddock fillets by the use of pour plates of Peptone-Iron Agar. Subsurface colonies appear intensely black, whereas surface colonies are black or gray. A highly sensitive soft-agar-gelatin overlay technique has been found useful for directly determining the numbers of weakly and strongly proteolytic organisms from fish tissue.
Effect of Type of Red Blood Cells on Antistreptolysin O Titer
Authors: Klein George C. , Addison Betty V. , Boone James S. , Moody Max D.
Published: December 2020

Antistreptolysin O (ASO) titers were determined on 117 human sera with rabbit, human, and sheep red blood cells (RBC) as the indicator system in the ASO tube test. The titers of 65% of the sera were one dilution step higher when a 5% suspension of sheep RBC was used instead of a 5% suspension of rabbit RBC. Titers were one dilution step higher in 42.7% of the sera when a 5% suspension of human RBC was used instead of a 5% suspension of rabbit RBC. The best comparability of titers was between a 5% suspension of human RBC and a 2.5% suspension of sheep RBC.
Yellow Fever Virus
Authors: Spector Sheldon , Tauraso Nicola M.
Published: December 2020

Heretofore, the most reliable way of measuring yellow fever virus antibody was to use the mouse neutralization (MN) test employing either suckling or weanling mice. Certain disadvantages (e.g., expense both of animals and of maintaining a mouse colony, allergic reactions of many laboratory workers, and the relatively long time, 21 days, before end points are reached) are inherent in any program with mice or other laboratory animal species and have discouraged the use of the MN test by many laboratories. A previously reported plaque neutralization (PN) test with primary chick embryo cell cultures could not be consistently reproduced by later investigators. We have developed a convenient and reproducible PN test employing the MA-104 embryonic rhesus monkey kidney cell culture and a single agar-overlay procedure. When compared with MN tests with newborn (1 to 3 days old) and weanling (16 to 20 g, 24 to 28 days old) mice inoculated by the intracranial route, the PN test was the most sensitive for measuring neutralizing antibody; it was also less variable, less costly, and it achieved results in the shortest period of time. End points could be determined in 5 to 6 days for the PN test as compared to 21 days for the MN test.
Effects of Jet-Fuel Microbial Isolates on a Polyurethane Foam
Authors: Hedrick H. G. , Crum M. G.
Published: December 2020

Jet-fuel microbial isolates were studied for effects on a polyurethane foam material that has been proposed as a baffling material for use in aircraft fuel tanks. Evidence was found that a polyesterurethane foam gave increased cell counts and oxygen uptake with a bacterial isolate, and extensive matting with fragmentation and decreases in tensile strength of the foam with a fungal isolate. The polyurethane foam was affected by activity of the jet-fuel microbial isolates to an extent that would cause serious microbiological problems in the fuel tanks of jet aircraft.
Production of Acetic Acid and Other Volatile Compounds by
Leuconostoc citrovorum
and
Leuconostoc dextranicum
Authors: Keenan T. W.
Published: December 2020

Single-strain milk cultures of
Leuconostoc dextranicum
are capable of reducing added acetaldehyde, propionaldehyde, and butanone to the corresponding alcohols at 30 C.
L. dextranicum
and
L. citrovorum
reduced propionaldehyde to
n
-propanol quantitatively in 30 hr, and the reduction of this compound paralleled culture growth. Under unagitated conditions, these organisms produced large amounts of acetic acid and ethyl alcohol. The yield of acetic acid increased when cultures were agitated during growth. This increase in acetic acid production was accompanied by a 20- to 70-fold decrease in ethyl alcohol. The addition of acetaldehyde to the fermentation caused a reduction in the final concentration of acetic acid.
Yields of Bacterial Cells from Hydrocarbons
Authors: Wodzinski Richard S. , Johnson Marvin J.
Published: December 2020

A strain of
Nocardia
and one of
Pseudomonas
, both isolated on pristane (2,6,10,14-tetramethylpentadecane), gave cell yields of approximately 100% on
n
-octadecane and pristane. Both organisms grew more rapidly on the
n
-octadecane than on the pristane. A mixed culture, isolated on 3-methylheptane, whose two components were identified as species of
Pseudomonas
and of
Nocardia
, gave approximately 100% cell yields and grew with generation times of about 5 hr on
n
-heptane,
n
-octane, and 2-methylheptane. The generation time on 3-methylheptane was 8.6 hr and the cell yield was only 79%. A strain of
Pseudomonas
isolated from naphthalene enrichments and one from phenanthrene enrichments both gave a cell yield of 50% on naphthalene. The phenanthrene isolate gave a cell yield of 40% on phenanthrene. A
Nocardia
species isolated on benzene gave a 79% cell yield on benzene. The generation times of the bacteria isolated on aromatic hydrocarbons were related to the solubility of the aromatic hydrocarbons on which they were grown; the more insoluble hydrocarbons gave slower growth.
Characteristics of Myxobacteria Isolated from the Surface of Freshwater Fish
Authors: Pacha R. E. , Porter Sook
Published: December 2020

A study was made of 32 nonpathogenic myxobacterial isolates obtained from a variety of fish taken in the Pacific Northwest. Morphological, cultural, biochemical, and serological studies were carried out on these strains. All were found to be members of the genus
Cytophaga
. Two myxobacterial strains pathogenic to fish were also included in this study for comparative purposes. These pathogenic organisms were found to be culturally and physiologically similar to some of the nonpathogenic strains. Antiserum against the pathogenic species, however, showed no cross agglutination when tested against the other myxobacterial isolates. As a result, serological procedures appear promising as a rapid means for distinguishing pathogenic myxobacteria from one another and from saprophytic myxobacteria commonly found on fish.
Significance of Coliforms and Enterococci in Fish Products
Authors: Varga S. , Anderson G. W.
Published: December 2020

Coliforms, more recently fecal coliforms, and enterococci are often used to assess the hygienic quality of foods. Although these bacteria serve rather successfully as an index of fecal pollution of water supplies, their usefulness in measuring fecal pollution in foods is less than satisfactory. The ratio and correlation of coliforms and enterococci in fish-fillet and lobster-meat samples led us to conclude that these organisms originated from improperly sanitized working surfaces, where they survive and multiply, and not from fecal pollution. Therefore, the presence of coliforms and enterococci in fish fillets and lobster meat reflects the quality of fish-plant sanitation and not the direct fecal pollution of these products.
Reduction of a Tetrazolium Salt in Determining Growth Activity of Yeast-Phase
Histoplasma capsulatum
Authors: Reca Maria E.
Published: December 2020

A colorimetric method using a tetrazolium compound, 3,4,5-dimethylthiozalil-(1 or 2),2,5-diphenyltetrazolium bromide (TTBr), was developed for studying the growth activity of yeast-phase
Histoplasma capsulatum
. Materials extracted in phosphate buffer,
p
H 7.0, from cells at different stages of growth reduced TTBr. Colorimetric changes were correlated with enzymatic activity. Under standardized conditions specified herein, the optical density of the reduced tetrazole was an index of the growth activity of the organism.
Effect of γ Irradiation on the Microflora of Freshwater Fish
Authors: Kazanas N. , Emerson J. A.
Published: December 2020

Maximal shelf life was determined and microbial flora were compared for irradiated (0.1 and 0.2 Mrad) and nonirradiated yellow perch fillets stored at 1 C. Shelf life was estimated by organoleptic determinations. Microbiological studies included determination of the effects of irradiation on the total aerobic microbial population, lag phase, and rate of growth. Genera of organisms isolated from fillets through the course of microbial spoilage were identified, and the proteolytic activity of the organisms was determined. Plate counts for fish prior to irradiation showed the presence of approximately 10
6
organisms per g of sample. Irradiation to 0.1 and 0.2 Mrad produced 1.4 and 3 logarithm reductions of the initial count, respectively. Irradiation to 0.1 and 0.2 Mrad approximately doubled the product's shelf life. Organisms initially isolated from the nonirradiated fillets, in order of decreasing number, consisted of
Flavobacterium, Micrococcus-Sarcina, Achromobacter-Alcaligenes-Mima, Pseudomonas, Microbacterium, Vibrio, Bacillus, Corynebacterium, Lactobacillus, Brevibacterium
, and
Aeromonas
. By the 6th and 9th days of fillet storage,
Pseudomonas
and the
Achromobacter
group were the predominant organisms. All members of the genus
Flavobacterium
, but not all members of the genus
Pseudomonas
, were proteolytically active on raw fish juice-agar and skim milk-agar media. The
Achromobacter
group was found to be nonproteolytic on both media. Residual flora of fillets irradiated to 0.1 and 0.2 Mrad consisted of the
Achromobacter
group,
Lactobacillus, Micrococcus-Sarcina
, and
Bacillus
. Their sequence in predominance, however, varied with dose level. Not all proteolytic bacteria in the fillets were eliminated by 0.1 and 0.2 Mrad; proteolytic
Micrococcus-Sarcina
survived these treatments.
Assessment of Aerosol Stability of Yellow Fever Virus by Fluorescent-Cell Counting
Authors: Mayhew Charles J. , Zimmerman W. Douglas , Hahon Nicholas
Published: December 2020

The effects of three temperatures [30, 50, and 80 F (-1.11, 10, and 26.67 C)] and three relative humidities (30, 50, and 80%) on biological and physical decay rates of aerosols of yellow fever virus were investigated. Neither temperature nor relative humidity, independently or jointly, significantly affected biological or physical decay rates. The advantages of assaying yellow fever virus by the fluorescent-cell counting technique are discussed.
Influence of Catalase Activity on Resistance of Coagulase-positive Staphylococci to Hydrogen Peroxide
Authors: Amin V. M. , Olson N. F.
Published: December 2020

Catalase activities of intact cells and cell-free extracts of coagulase-positive staphylococcal cultures 105B and 558D isolated from milk, culture 25042 from a clinical source, and
Staphylococcus aureus
196E were determined at 32.2 C. Cultures were treated with 0.025 and 0.05% hydrogen peroxide at 37.8 and 54.4 C and without hydrogen peroxide at 54.4 C to determine the relationship between catalase activity and resistance to these treatments. The relationship held true for cultures 105B and 196E; culture 105B had the lowest catalase activity and lowest resistance to H
2
O
2
at 37.8 C, whereas
S. aureus
196E possessed a high catalase activity and was most resistant at 37.8 C. Catalase activities of cell-free extracts of cultures 25042, 558, and 196E were similar, but resistance to H
2
O
2
at 37.8 C was greater for culture 196E. The lower resistance of culture 25042 was related to low catalase activities of whole cells of this culture, which were only one-third that of whole cells of culture 196E. Culture 558 was least resistant to heat treatment at 54.4 C and showed the greatest sensitivity to added H
2
O
2
at this temperature.
Fluorescent-Antibody Reagent for the Identification of
Cryptococcus neoformans
Authors: Pidcoe Vern , Kaufman Leo
Published: December 2020

A sensitive and diagnostically applicable conjugate for the rapid and accurate detection and identification of
Cryptococcus neoformans
has been developed.
C. neoformans
rabbit antisera were produced by 14 daily intravenous injections of 36 million cells for a total dosage of approximately 500 million cells. Cross-staining reactions with species of
Cryptococcus
other than
C. neoformans
, as well as with
Candida
species, were eliminated by adsorption of the
C. neoformans
conjugate with cells of
C. diffluens
and
C. krusei
.
Growth-promoting Activity of Spent Sulfite Liquor for
Sphaerotilus natans
Growing in a Continuous-Flow Apparatus
Authors: Dias F. F. , Okrend Harold , Dondero Norman C.
Published: December 2020

The calcium in ammonia-base spent sulfite liquor, unlike that in calcium-base spent liquor, is not available for growth of
Sphaerotilus natans
. It has not been possible to obtain a mixed slime with
Sphaerotilus
as the dominant organism in a continuous-flow apparatus fed spent sulfite liquor.
Rapid Method for Characterization of Actinomycetes by Cell Wall Composition
Authors: Boone Clarence J. , Pine Leo
Published: December 2020

To achieve a rapid identification of the cell wall components of actinomycetes, several modifications of the procedure of Cummins and Harris were developed. Purified cell walls were prepared by extraction of whole cells with 0.1 N NaOH. A 2-hr 2 N HCl hydrolysate was prepared for identification of sugars. A 2-hr 6 N HCl hydrolysate was prepared for amino acid analysis. Two-dimensional paper chromatography was run on 19-cm papers. Total time required for a single analysis was approximately 24 hr. This procedure gave qualitative results which were completely satisfactory for differentiation of certain species in the genus
Actinomyces
and in related genera.