bluuebunny/crossref_metadata_2025 huggingface dataset:
Survey of Chemical Compounds Tested In Vitro against Rumen Protozoa for Possible Control of Bloat
Authors: Willard F. L. , Kodras Rudolph
Published: December 2020

Over 170 chemical agents were screened for antiprotozoal action in bovine ruminal fluid. Compounds were tested at 0.1 and 0.05% concentrations. Tested compounds included inorganic compounds, antibiotics, biocides, neuromuscular agents, arsenicals, plant and animal hormones, antimalarials, surface-active agents, anthelmintics, and many others. The most active compounds were cupric sulfate, nickel sulfate, nitrofurazone, hydrogen peroxide, dodecyl sodium sulfate, pelargonic acid, iodoacetic acid, 1-diethylaminoethylamino-4-methylthiaxanthrone, sodium arsanilate, sodium arsenate, bismuth glycolyl arsanilate, 1-β-hydroxyethyl-2-methyl-5-nitroimidazole, and
p
-nitroaniline. Copper ion was not particularly effective against entodinia; nickel ion had no effect on holotrichs. Hydrogen peroxide and iodoacetic acid were effective at a concentration of 0.005%. Anionic surface-active agents were very effective, especially long-chain sulfates and phosphates. These antiprotozoal agents warrant further in vivo studies for possible use in treating or curing bloat in ruminants.
Enhancement of Antibiotic Activity against
Staphylococcus aureus
by Exposure to Hyperbaric Oxygen
Authors: Bornside George H.
Published: December 2020

Growth of
Staphylococcus aureus
ATCC 6538P was studied in stationary broth cultures (11 mm deep) exposed to hyperbaric oxygen (100% O
2
at 3 atm absolute). The minimal inhibitory concentration (MIC) of the following antibiotics was determined after exposure to high-pressure oxygen (HPO) for 3, 6, and 12 hr: penicillin, streptomycin, tetracycline, oxytetracycline, kanamycin, and cephalothin. Logarithmic growth during exposure to HPO was retarded 60%. Air at 3 atm absolute did not retard growth. The longer the exposure of tube dilution tests to HPO, the lower the MIC. Regardless of the antibiotic used, MIC values relative to 100% for unexposed controls were similar for given exposures, and averaged 73% after 3 hr of exposure to HPO, 53% after 6 hr, and 34% after 12 hr. Similar enhancement with HPO and an iodophor suggests occurrence of a general phenomenon with antibacterial agents. Although HPO alone is primarily bacteriostatic, combined therapy with antibiotics and HPO may be useful against bacterial infections because the therapeutic effectiveness of a maximal dosage of antibiotic could be increased.
Microbiological Burden on the Surfaces of Explorer XXXIII Spacecraft
Authors: Powers Edmund M.
Published: December 2020

The Explorer XXXIII Spacecraft (Anchored Interplanetary Monitoring Platform, or AIMP) was decontaminated to prevent gross contamination of the moon with terrestrial microorganisms. Assay of the total spacecraft surface before and after decontamination showed that the decontamination procedure reduced the viable microbiological burden from 1.40 × 10
6
to 3.60 × 10
4
. However, assembly of parts which were not decontaminated for engineering reasons or were not assembled under cleanroom conditions increased the viable microbial burden at the time of launch to 2.62 × 10
5
.

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Fig. 2
Agar-Gel Precipitin-Inhibition Test for Coccidioidomycosis
Authors: Ray John G. , Converse John L.
Published: December 2020

In this study of saprophytic and parasitic growth-phase extracts of
Coccidioides immitis
, an antigen from the spherule culture supernatant fluid detected a specific antibody in heretofore serologically negative suspect coccidioidomycosis human sera when diffused in agar-gel. This antigen-antibody reaction occurred also in some of the serologically positive human coccidioidomycosis sera. This study indicates that this antigen-antibody reaction should be utilized as a possible routine serological test for complete serodiagnosis.
In Vitro Activity of Doxycycline Against Bacteria from Clinical Material
Authors: Isenberg Henry D.
Published: December 2020

Doxycycline (α-6-deoxy-oxytetracycline) was tested against various bacteria of recent clinical origin with 30-μg discs. The antibiotic susceptibility of these bacteria to commonly used antimicrobial agents was also established. Those bacteria which responded with equivocal zones of inhibition about the tetracycline compounds were tested by the tube dilution technique. Staphylococci and enterococci consistently displayed greater in vitro susceptibility to doxycycline than to tetracycline or demethylchlortetracycline.
Oxygen-Transfer Demand of
Bacillus licheniformis
under Conditions of Submerged Cultivation
Authors: Matelov� V. , Břečka A.
Published: December 2020

We have studied the influence of oxygen transfer in the biosynthesis of bacitracin. The intensity of oxygen transfer within the range of 0.37 to 2.43 ml of O
2
per ml per hr during growth of the inoculum has no effect. The production of bacitracin is very important in the actual fermentation phase. Oxygen transfer must not fall below the lowest limit; in the case of fermentation medium with 5 and 6% peanut meal, 0.97 and 1.39 ml of O
2
per ml per hr, respectively, are the limits. Increased oxygen-transfer above the optimal value does not lead to a reduced production of bacitracin.
Utilization of Inorganic Nitrogen Compounds by
Sphaerotilus natans
Growing in a Continuous-Flow Apparatus
Authors: Dias F. F. , Heukelekian H.
Published: December 2020

Sphaerotilus natans
was grown, attached, in a continuous-flow apparatus with inorganic nitrogen compounds (NH
4
Cl, NaNO
2
, or NaNO
3
) as the only sources of nitrogen. The growth rate with NH
4
+
-containing medium did not differ from that with media containing glutamate or Casitone as the nitrogen source.

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Fig. 2
Permanent Turbidity-Standards
Authors: Roessler William G. , Brewer Carl R.
Published: December 2020

Permanent turbidity reference standards suitable for measurement of microbial suspensions were prepared by suspending finely divided titanium dioxide in aryl sulfonamide-formaldehyde or methylstyrene resins. Turbidities of these standards, adjusted to a useful range for microbiological and immunological studies, were compared with other reference standards in use today. Tube holders for a Coleman Photonephelometer and a Nepho-Colorimeter were modified to eliminate the water well and to allow use of optically standardized 10-, 16-, or 18-mm test tubes. The standards and the tube holders have been used satisfactorily for more than 12 years.
Aerobic Heterotrophic Bacterial Populations of Sewage and Activated Sludge
Authors: Prakasam T. B. S. , Dondero Norman C.
Published: December 2020

The replica-plating technique and Lochhead's nutritional method were combined in exploratory experiments to test their feasibility as useful means for characterizing the aerobic heterotrophic flora of activated sludge and to minimize the burdensome process of isolation, purification, and testing of isolates. In the test run, the method was about 86% reliable at the 0.05 level of significance. About 40% of the total number of bacteria able to grow on an aqueous extract of activated sludge did not grow on media containing glucose, amino acids, growth factors, and inorganic salts. The requirement for activated sludge extract suggested the existence of a requirement for unidentified nutrients contained in the activated sludge extract.
Immunofluorescence Technique for the Detection of Salmonellae in Various Foods
Authors: Insalata N. F. , Schulte S. J. , Berman J. H.
Published: December 2020

Salmonella
species have been detected in nine food varieties by use of fluorescent antibodies without false-positive or false-negative results. Test antisera were specially prepared, commercially available, conjugated polyvalent O globulin absorbed with cultures of
Escherichia coli
and
Citrobacter freundii
, and polyvalent phase II H globulin antibodies. Use of this technique permits a decrease of 24 hr in time normally required for
Salmonella
detection when compared with cultural
Salmonella
recovery methods.
Enzymatic Detection of the Growth of
Staphylococcus aureus
in Foods
Authors: Chesbro W. R. , Auborn K.
Published: December 2020

A specific method has been developed for the extraction and measurement of staphylococcal nuclease in foods in which
Staphylococcus aureus
has grown. The method was used to compare staphylococcal growth with nuclease production in foods under varying conditions of temperature, aerobiosis, and competition from other microorganisms. It was concluded that the nuclease is produced under any conditions that permit growth of
S. aureus
, and little or no interference with the test was encountered either from mixed, natural populations or from a variety of pure, laboratory cultures. Nuclease and enterotoxin A production were shown to vary in synchrony for the 234 (Casman) strain of
S. aureus
, and the sensitivity of the enzymatic detection of nuclease was comparable to the sensitivity of serological detection of enterotoxin A. It was found that 15 min at 121 C was required to reduce the nuclease activity in slurries of contaminated ham below the level present in the unheated slurry. The extraordinary heat resistance of the nuclease permits its detection even in foods heated subsequent to the growth of
S. aureus
. The nuclease analysis requires about 3 hr to complete and requires no unusual equipment or reagents.
Fluorescein-labeled β-Glucosidase as a Bacterial Stain
Authors: Pital Abe , Janowitz Sheldon L. , Hudak Charles E. , Lewis Evelyn E.
Published: December 2020

Fluorescein isothiocyanate-labeled β-glucosidase was used as a simple staining reagent with selected gram-positive and gram-negative organisms. Staining in situ appeared to be dependent on the presence of accessible glycosidic-type linkages in the bacterial cell wall. Extensive wall damage or lysis did not occur when stained cells were suspended in washing and mounting solutions. The apparent specificity of labeled enzyme for wall substance was tested by blocking reactions, staining of isolated cell walls, and failure to stain substances lacking appropriate glycosidic linkages. Severe cell wall lesions were produced after prolonged contact with labeled enzyme, and this phenomenon may also be related to staining specificity. Gram-negative organisms and spores were poorly stained unless protected glycopeptide substrate was previously exposed by treatment of cells with thioglycolic acid or dilute alkaline sodium hypochlorite solution. A potential for staining tissues and cell lines may also exist. Some possible applications of labeled enzymes are briefly discussed.
Effect of Cookery and Holding on Hams and Turkey Rolls Contaminated with
Clostridium perfringens
Authors: Strong Dorothy H. , Ripp Nancy M.
Published: December 2020

Canned hams, turkey rolls, and ground-beef casseroles were inoculated with a mixture of vegetative cells and spores of selected strains of
Clostridium perfringens
, in approximately known numbers. After cooking and holding at different temperatures for various times, samples of the food were plated directly on sulfadiazine-polymixin-sulfite-agar. In all cases, small but measurable percentages of the organisms survived cookery. The number of cells viable after cookery of the ham or turkey was influenced by the position of the slice of meat in the roast as well as by the final temperature to which the product was heated. Plate counts for turkey or beef casserole held at temperatures in the range of 5 to 10 C for 48 hr indicated stabilization of the population or a tendency to decrease. At 24 C, the multiplication of cells was apparent in 4 hr and rapid in 6 hr. When the food was maintained at 68 C, populations remained viable for 6 hr and the counts did not change markedly. In turkey maintained at 37 C, the number of cells increased sharply within 4 hr.
Morphology of Submerged Growth of Streptomycetes as a Taxonomic Aid
Authors: Tresner H. D. , Hayes Jean A. , Backus E. J.
Published: December 2020

In a study of the submerged growth morphology of 145 different streptomycetes in A C Broth, the species
Streptomyces aureofaciens
was observed to represent an unusual type. It was characterized by profuse mycelial segmentation, transformation of disarticulated fragments of segmented mycelium into chains of thickened arthrospores, and formation of filiform appendages on the arthrosporic cells giving an insectival appearance to these elements. This unusual morphology was determined to be a consistent feature in 110 strains of
S. aureofaciens
studied, hence suggesting a useful taxonomic aid in identification of this species. Preliminary studies of multiple strains of many different
Streptomyces
species indicate that other useful taxonomic features based on morphology of submerged growth are found in a significantly large part of the genus.
Rubella Virus: Continuous and Concurrent Production of Complement-fixing Antigen and Infectious Virus in Suspension Cultures
Authors: Vincent M. M. , Gitnick G. L. , Fabiyi A. , Hensen S. A. , Sever J. L. , Huebner R. J.
Published: December 2020

Rubella complement-fixing (CF) antigen and infectious virus were produced continuously and concurrently for as long as 63 days in suspension cultures of BHK-21 cells prepared from uncloned monolayer stock cultures. CF titers ranged from 1:4 to 1:32, and the peak infectivity titer was greater than 8.0 (TCID
50
log
10
) per ml. Suspension cultures could be recultivated after prolonged storage in liquid nitrogen. The resulting monolayer or suspension cultures also produced CF antigen. Suspension cultures provide an effective system for the long-term continuous and concurrent production of rubella virus diagnostic reagents.
Observations on the Occurrence, Distribution, and Seasonal Incidence of Blue-green Algal Viruses
Authors: Safferman Robert S. , Morris Mary E.
Published: December 2020

Phycovirus populations were found in 11 of the 12 waste stabilization ponds studied. These populations were comprised solely of blue-green algal (BGA) viruses. Two virus types were observed, one of which was related to the previously reported LPP-1 virus. The incidence and magnitude of the LPP group indicated that several of the ponds supported well-established BGA virus populations of this type. Counts as high as 270 plaque-forming units/ml were noted; however, marked differences in the nature and magnitude of these BGA viruses were apparent even in geographically related ponds of similar design. Of the algal strains found dominant in these ponds, none was of the type reported susceptible to the LPP viruses.
Fat Absorption from the Small Intestine of Gnotobiotic Chicks
Authors: Cole John R. , Boyd F. M.
Published: December 2020

The small intestine of 3-week-old gnotobiotic chicks was divided into five equal segments for analysis. Since it has been found that most fat absorption occurs in the third and fourth segments, they were selected for study. The major fatty acids in the diet and the feces of chicks were palmitic, stearic, oleic, and linoleic acids. Consequently, these fatty acids were selected for quantitative analyses in the absorption studies. Germ-free chicks were contaminated at 7 days of age with bacteria isolated from the third and fourth intestinal segments, except for the
Escherichia coli
contaminant, which had been previously isolated from a chicken with air sac disease. There were two different degrees of response by chicks to the bacterial contaminants in this study. For this reason, the chicks were placed retrospectively into two categories according to their response to environmental conditions. The first category (A) contained germ-free chicks and chicks monocontaminated with
E. coli, Staphylococcus
, or
Lactobacillus
. The second category (B) was composed of conventional chicks and chicks monocontaminated with
Streptococcus faecalis
or
Clostridium welchii
, dicontaminated with
S. faecalis
and
C. welchii
, and accidentally polycontaminated with coliforms and anaerobic gram-positive bacilli. Chicks in category A demonstrated increased absorption of palmitic and stearic acids and total fat as compared to category B chicks. Conversely, category B chicks showed slightly increased absorption of oleic and linoleic acids. Thin-layer chromatographic analyses demonstrated that cholesterol esters were affected similarly to fatty acids. The site of absorption of fatty acids, cholesterol esters, and total fat was unchanged, regardless of the environment.

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Fig. 1
Growth of Myxococci in Suspension in Liquid Media
Authors: Sch�rmann C.
Published: December 2020

Growth of different strains of myxococci in various liquid media was studied in Erlenmeyer flasks and in small fermentors. Medium containing a small concentration of agar allowed the myxobacteria to grow in the liquid phase in suspension. The dry weight of the cells increased about 100 to 200%. Substitution of other thickening substances for agar caused increased growth with all of eight tested agents.
Sporulation of
Bacillus stearothermophilus
Authors: Thompson P. J. , Thames O. A.
Published: December 2020

A broth medium containing tryptone and manganese sulfate supported heavy sporulation of
Bacillus stearothermophilus
ATCC 7953 (NCA 1518) and four isolates identified as
B. stearothermophilus
. Maximal spore yields were obtained by use of inocula grown anaerobically in a medium containing glucose with aeration of sporulation medium via bubbling. After an extended stationary period, sporulation occurred concurrently with vegetative growth between 6 and 8 hr of incubation at 60 C. Omission of glucose from the inoculum or use of a “young” (2 hr) inoculum abolished the stationary period, but decreased spore yields. A requirement of oxygen for rapid vegetative growth and sporulation was demonstrated. Manganese (15 to 30 ppm) stimulated sporulation but did not enhance cell growth.
Properties of
Pseudomonas enalia
, a Marine Bacterium Pathogenic for the Invertebrate
Crassostrea gigas
(Thunberg)
Authors: Colwell R. R. , Sparks A. K.
Published: December 2020

Bacteriological investigations of dead and dying oysters in populations of
Crassostrea gigas
grown in Hood Canal, Oyster Bay, and Willapa Bay, Washington, were undertaken. Living, and presumably normal, oysters within the same sample set were also examined. Results indicated that the natural flora of
Crassostrea gigas
(Thunberg) is composed of organisms representing the genera
Pseudomonas, Achromobacter, Flavobacterium
, and
Vibrio
. Pollution indicator organisms such as
Escherichia coli
were not found. The flora of dead or dying oysters included a somewhat greater incidence of
Pseudomonas
sp.; a seawater-requiring organism isolated on several occasions from oyster gapers which had been collected from different geographical areas was identified as
P. enalia
. A description of the organism has been provided, and the characteristics are listed to facilitate identification by other workers encountering the organism in future studies of a similar kind. The seawater requirement exhibited by
P. enalia
was deduced to be a requirement for sodium chloride for growth of the organism. Experiments to determine the pathogenicity of
Pseudomonas enalia
were performed by use of experimentally infected animals maintained in aerated seawater tanks. Death of
C. gigas
occurred when the animal body tissue was injected with viable bacterial cell suspension. Results of histological studies of the normal and infected oyster tissue suggest that bacterial invasion of the tissue occurred.

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Fig. 1

Fig. 2
Effect of Growth Rate on the Synthesis of Penicillin by
Penicillium chrysogenum
in Batch and Chemostat Cultures
Authors: Pirt S. J. , Righelato R. C.
Published: December 2020

The kinetics of penicillin production by
Penicillium chrysogenum
Wis 54-1255 in a glucose-limited chemostat and in batch cultures are reported. The specific production rate of penicillin, q
pen
(units per milligram of dry weight per hour) was independent of specific growth rate over the range 0.014 to 0.086 hr
-1
. Growth was stopped by restricting the glucose supply to the “maintenance ration,” that is, the glucose requirement of the organism at zero growth rate with all other nutrients in excess. Under such conditions, the organism dry weight remained constant, but the q
pen
fell approximately linearly to zero at a rate inversely related to the previous growth rate. Glucose supplied in excess of the maintenance ration inhibited the decay of q
pen
. At a critical growth rate between 0.009 and 0.014 hr
-1
, the decay was completely inhibited. Quantitative expressions for the q
pen
of growing and nongrowing cultures were derived and used to predict the steady-state concentrations of penicillin accumulating in one- and two-stage continuous processes. A rational explanation of the kinetics of penicillin accumulation in batch cultures is given, relating the rate of penicillin synthesis to growth rate. It is concluded that an important role of corn steep liquor (CSL), a heterogeneous carbon and nitrogen source commonly used in penicillin production media, is the provision of substrates which allow a high concentration of mold to be reached before the growth rate falls below the critical value. CSL had no significant effect on q
pen
.
Effect of Algicidal Quaternaries on the Germicidal Activity of Chlorine on Swimming Pool Water
Authors: Koski T. A. , Ortenzio L. F. , Stuart L. S.
Published: December 2020

The Swimming Pool Water Disinfectant Test Method of the Association of Official Analytical Chemists was used to determine the effect of the accepted level of 2 ppm of some commercial quaternary ammonium algicides on the germicidal activity of chlorine. Accurate determinations on the amounts of residual available chlorine in chlorine-quaternary mixtures could not be made by the usual chemical methods. This made it necessary to base all comparisons on the starting concentrations of available chlorine rather than the final concentration as specified in the method employed. No evidence was obtained to support the use of lower concentrations of residual available chlorine for disinfection in the presence of algicidal quaternaries than those commonly recognized as effective by the American Public Health Association. The rate of kill against the gram-positive test organism
Streptococcus faecalis
was faster in quaternary-chlorine mixtures than in the sodium hypochlorite control solutions. The practical significance of this result in the bench method identified cannot be ascertained in the absence of more sensitive and precise chemical procedures for determining concentrations of residual available chlorine in the presence of quaternaries or in actual swimming pool tests.
Inhibition of Microorganisms by Topical Anesthetics
Authors: Kleinfeld Jerome , Ellis Philip P.
Published: December 2020

The effect of various topical anesthetics and their preservatives on the growth of
Pseudomonas aeruginosa, Staphyloccoccus albus
, and
Candida albicans
was investigated. The topical anesthetics were proparacaine HCl, tetracaine HCl, cocaine HCl, and benoxinate HCl. The preservatives were chlorobutanol and butyl
p
-hydroxybenzoate. Proparacaine inhibited
C. albicans
but not
P. aeruginosa
or
S. albus
. All three test organisms were inhibited to varying degrees by tetracaine, benoxinate, cocaine, chlorobutanol, and butyl
p
-hydroxybenzoate.
Effect of Water Vapor on Lyophilized
Serratia marcescens
and
Escherichia coli
Authors: Dewald R. R. , Browall K. W. , Schaefer L. M. , Messer A.
Published: December 2020

Dried
Serratia marcescens
ATTC 14014 and
Escherichia coli
ATTC 4157 cells were exposed to various partial pressures of purified water vapor. The colony-forming ability of the
S. marcescens
was unimpaired when the dried organisms were stored in water-vapor atmosphere such that
P/P
0
< 0.55 or
P/P
0
= 1.0 (where
P
is the pressure of the water vapor in contact with the organisms, and
P
0
is vapor pressure of pure water at 25 C). During storage under water-vapor atmospheres with
P/P
0
between 0.6 and 1.0, the colony-forming ability of the dried
S. marcescens
was destroyed. The inactivation by water vapor followed the expression — ln
N/N
0
=
Kt
1/2
, where
N
0
and
N
are the number of viable organisms before and after exposure, respectively,
t
is time, and
K
is a pseudo constant which is dependent upon the partial pressure of the water vapor at 25 C. Similar results were obtained with dried
E. coli
. The addition of solutes to the suspending media before freeze-drying was found to influence the stability of the organisms during exposure to water vapor.
Substrate Effect on 2,3-Butylene Glycol Production by
Rhizopus nigricans
and
Penicillium expansum
Authors: Fields M. L. , Richmond Bonnie
Published: December 2020

Rhizopus nigricans
and
Penicillium expansum
produced 2,3-butylene glycol which accumulated in natural and artificial media with time. Mycelial mats of
P. expansum
decreased the quantity of a diacetyl substrate and converted part of this substrate into acetylmethylcarbinol (AMC) and 2,3-butylene glycol. Mycelial mats of
P. expansum
also decreased AMC substrate with the formation of 2,3-butylene glycol. 2,3-Butylene glycol decreased slightly during incubation with the fungal mat. The formation of AMC was suppressed significantly by cysteine and ascorbic acid.
Continuous Propagation of
Trichosporon cutaneum
in Cheese Whey
Authors: Atkin Cavit , Witter L. D. , Ordal Z. John
Published: December 2020

Trichosporon cutaneum
, a nonfermenting yeast, was used to convert cheese whey lactose into microbial cell material. The doubling time for this organism in a laboratory-scale continuous propagator was 2 hr in a whey medium fortified with ammonium sulfate and corn steep liquor. Cellular growth and efficiency of conversion of lactose to cell material was higher than with
Saccharomyces fragilis
. When grown in whey, the nitrogen content of
T. cutaneum
was 3.5% and the distribution of amino acids per gram of cell protein was similar to that of commercial food yeasts.
Quantitative Analyses of Certain Enteric Bacteria and Bacterial Extracts
Authors: Glenn William G. , Ralston James R. , Russell Warren J.
Published: December 2020

Bacterial extracts prepared by ultrasonic disruption were reacted with both narrow- and broad-spectrum reference (homologous) and cross-reacting (heterologous) precipitins produced in rabbits. Quantitation of the reaction was obtained by densitometry of the antigen-antibody interface. Comparisons were made of sonic extracts from various starting populations all equated to the same nitrogen concentrations, and of various nitrogen levels derived from five bacterial population levels prepared separately. Sources of error are probed to show under what circumstances cross-reactions would be of greater magnitude than reference ones. The feasibility was shown of using quantitative densitometry of the interface combined with broadly reacting precipitins to identify bacteria on an intergeneric and interspecies scale. Problems associated with the use of absorbed or monospecific precipitins are explained.
Production of Hyaluronic Acid by a Streptococcal Strain in Batch Culture
Authors: Holmström Björn , Řičica J.
Published: December 2020

A simple method for the production and preparation of hyaluronic acid (HA) is described. Three media were tested, which all supported relatively good yields of cells, but only in one of them were appreciable amounts of HA formed. In this medium, HA was produced during the logarithmic growth phase and showed a molecular weight of 7.3 × 10
5
. HA prepared from 24-hr cultures of the same organism had a molecular weight of only 2.6 × 10
5
. The kinetics of HA production in batch culture were studied, as well as of cell production and glucose consumption.
Friend Leukemogenic Virus-neutralizing Antibody from Mouse Ascitic Fluid
Authors: March R. W. , Chirigos M. A. , Hook W. A. , Burka B. L.
Published: December 2020

Ascitic fluid antibody produced in C57/B1 mice immunized with Friend leukemogenic virus exhibited potent neutralizing activity. In vitro neutralization tests revealed that a mean neutralization index of 3.0 was achieved, and it was shown by sucrose gradient ultracentrifugation that this antibody resembled the 7
S
type. A mean yield of 6.7 ml of fluid per mouse per weekly paracentesis was obtained over an 8-week period. The ascitic fluid antibody to Friend virus was also active in vivo. Mice given antibody 3, 5, 7, and 9 days after infection with Friend virus did not develop the splenomegaly characteristic of Friend disease.
Effect of Lipid Materials on Heat Resistance of Bacterial Spores
Authors: Molin N. , Snygg B. G.
Published: December 2020

The apparent heat resistance of spores of
Bacillus megaterium, B. subtilis, B. cereus, B. stearothermophilus
, and
Clostridium botulinum
type E in lipids was investigated and compared with the resistance of the spores in phosphate buffer solution. The most pronounced increase in heat resistance was noted for
B. subtilis
and
C. botulinum
type E, the increase varying with the type of lipid used. A high water content of the lipids used as heating menstruum lowered the heat resistance of the spores. Possible explanations for the high heat resistance of spores in lipids are discussed.
Bacteriophage Aerosol Challenge of Installed Air Contamination Control Systems
Authors: Jensen Marcus M.
Published: December 2020

The effectiveness of installed air contamination control systems for removal of airborne microorganisms was determined. Seven separate systems were challenged with aerosolized T1 bacteriophage. Air samples were collected with Andersen samplers containing agar plates that had been swabbed with susceptible
Escherichia coli
. The advantages of using bacteriophage for testing air-handling systems are discussed. The air systems employed both filtration and ultraviolet irradiation and air-flow rates varied from 600 to 18,000 ft
3
/min. Reduction rates of airborne bacteriophage passing through the various air systems ranged from 99.8 to 99.99%.
Rumen Microorganisms in Buffalo from Southern Utah
Authors: Pearson Henry A.
Published: December 2020

Rumen microbial populations from buffalo (
Bison bison bison
Linn.) in southern Utah were identified on the basis of their morphology and staining characteristics. The rumen bacteria and ciliate protozoa were similar in number and kind to those found in domestic livestock.
Inactivation of Venezuelan Equine Encephalomyelitis Virus by γ-Radiation
Authors: Reitman Morton , Tribble Henry R.
Published: December 2020

Exposure of Venezuelan equine encephalomyelitis (VEE) virus (at -70 C) to 6 × 10
6
r γ-radiation (
60
Co) resulted in loss of lethality for young adult mice and guinea pigs, and loss of capacity to produce plaques or cytopathic effects in tissue culture. The suckling mouse was more sensitive for detecting live virus in radiated suspensions than was the adult mouse or guinea pig. Live virus was demonstrable in preparations exposed to 6 × 10
6
r but not in suspensions exposed to 8 × 10
6
r and more. The rate of inactivation of VEE virus by γ-radiation was an exponential function of the dosage.
Propagation of Rhinovirus on WI-38 Cell Monolayers in Rolling Bottles
Authors: Fenters James D. , Fordyce Patricia A. , Gerin John L. , Holper Jacob C.
Published: December 2020

Techniques are described for the propagation of rhinoviruses on WI-38 monolayers in rolling bottles. High yields of viruses were obtained, as indicated by infectivity titers and electron microscopy. When crude harvests were subjected to low-speed centrifugation and then filtered through a 0.45-μ membrane filter, little or no loss in infectivity titer was observed. However, electron microscopic examination indicated that the concentration of viral physical particles was reduced below detectable levels after filtration. The guinea pig potency test on the lot of unfiltered rhinovirus 14 vaccine prepared in rolling bottles indicated that this vaccine stimulated higher reciprocal serum-neutralizing titers than a rhinovirus 14 vaccine prepared in stationary monolayers.
Effect of Environment on Staphylococcal Lesions in Mice
Authors: Schmidt Jerome P. , Cordaro Joseph T. , Ball Robert J.
Published: December 2020

The influence of reduced barometric pressure on the development and healing of staphylococcal skin lesions in mice was investigated by exposing groups of animals to the test environment before, after, or before and after subcutaneous inoculation with 3.5 × 10
8
colony-forming units of a phage type 80 strain of
Staphylococcus aureus
. Similarly infected control animals were not exposed to the experimental environment. The results indicate that the lesions which developed in mice exposed to the test environment prior to infectious challenge were larger and healed at a slower rate than those in mice maintained at ground level before infection. Exposure after inoculation produced no demonstrable effect in the size or healing rate of the experimental lesions.
Cell Yields of Bacteria Grown on Methane
Authors: Vary Patricia S. , Johnson Marvin J.
Published: December 2020

Several mixed cultures of methane-oxidizing bacteria have been isolated. Among them, culture HR (consisting of two gram-negative rods, one 0.5 × 1.0 μ, the other 0.8 × 2 to 3 μ) was found to be the fastest-growing and to give the highest yields. Optimal conditions for rapid growth and high cell yields from methane were found to be: 30 C, NH
4
+
as nitrogen source, and
p
H 6.5. Requirements for CO
2
and Cu
++
were observed. Under these conditions, generation times of approximately 3 hr and cell yields from methane between 65 and 70% could be attained. Culture HR can utilize methane, methanol, ethyl alcohol, 1-propanol,
n
-butyl alcohol, and glucose, but not propane, for growth. Yeast and beef extracts are inhibitory. Carbon balances demonstrate that few if any products other than cells and CO
2
are produced from methane under the growth conditions used. Cell analyses for carbon, hydrogen, nitrogen, and amino acid content of culture HR were also made.
Experimental Evaluation of Liquid Film Resistance in Oxygen Transport to Microbial Cells
Authors: Borkowski John D. , Johnson Marvin J.
Published: December 2020

A membrane probe was used to monitor the dissolved oxygen concentrations in continuous cultures of
Candida utilis
and
Micrococcus roseus
growing at low dissolved oxygen concentrations and various agitation levels. For the yeast fermentations, increasing the agitation level within the range of 0.1 to 0.3 w per liter lowered steady-state dissolved oxygen concentrations in the fermentor. The steady-state dissolved oxygen concentration in the fermentor was not influenced by the agitation level within the range of 0.3 to 1.8 w per liter. With
M. roseus
, no effect of agitation on steady-state dissolved oxygen concentrations in the fermentor was observed within the range of 0.1 to 1.8 w per liter. It was concluded that, under the conditions used, a measurable transfer barrier from the liquid to the yeast cells existed at agitation levels below 0.3 w per liter and that this barrier did not exist at agitation levels above 0.3 w per liter. The transfer barrier from the liquid to the yeast surface could be represented by a stagnant film of liquid 0.6 × 10
-4
cm thick surrounding the cell at an agitation level of 0.10 w per liter. This film represented an oxygen concentration drop of 1.3 × 10
-7
M from the bulk of the medium to the cells under the experimental conditions.
Factors Influencing the Growth and Maintenance of Tubed Cultures of Embryonic Chick Cells
Authors: Thomas John P. , Ritter Hilda
Published: December 2020

An analysis was made of factors influencing the culture of embryonic chick cells. The procedures found to be optimal resulted in monolayers which survived for about 15 days.
Respiratory Chain of Antimycin A-producing
Streptomyces antibioticus
Authors: Řeháček Z. , Ramankutty M. , Kozová Jaroslava
Published: December 2020

An active respiratory chain system was demonstrated in sonically treated mycelium of
Streptomyces antibioticus
, the producer of antimycin A. The respiratory electron transfer from substrate to oxygen proceeded successively through flavoprotein(s),
b-, c
-, and
a
-type cytochromes, and terminated with the cyanide-sensitive cytochrome oxidase. The cytochrome composition of the culture was not affected by the age of the mycelium, the intensity of antimycin A production, or differences in the media. Slater factor, coenzyme Q, and vitamin K were not interposed as hydrogen carriers in the respiratory chain between flavoproteins and cytochromes. The oxidation of reduced nicotinamide adenine dinucleotide and succinate was unaffected by antimycin A. Evidence is presented in support of the absence of the antimycin A-sensitive site from the electron transport system of
S. antibioticus
.
Morphological and Biochemical Differentiation of
Achromobacter
and
Moraxella
(Debord's Tribe
Mimeae
)
Authors: Gilardi Gerald L.
Published: December 2020

To determine the most useful laboratory tests for the differentiation of
Achromobacter anitratus, Achromobacter lwoffii
, and
Moraxella duplex
(DeBord's tribe
Mimeae
), 157 strains of these bacteria, isolated from clinical specimens, were examined for their morphological and biochemical characteristics. There were several differences between these nonfermentative, gram-negative diplococci:
Moraxella
was nonglucolytic in either infusion base or synthetic base, oxidase-positive, and sensitive to penicillin, whereas
Achromobacter
produced variable carbohydrate activity, and was oxidase-negative and resistant to penicillin.
A. anitratus
was distinguished from
A. lwoffii
in that the former utilized infusion media containing either glucose or 10% lactose, whereas the latter did not. Both species utilized the same carbohydrates in a chemically defined medium, although the latter acted more sluggishly.
Comparison of Rumen Microbial Inhibition Resulting from Various Essential Oils Isolated from Relatively Unpalatable Plant Species
Authors: Oh Hi Kon , Jones M. B. , Longhurst W. M.
Published: December 2020

Essential oils were isolated from eight plant species which were relatively unpalatable to sheep and deer. The inhibitory potency of these essential oils upon sheep and deer rumen microorganisms was compared, in terms of total gas and volatile fatty acid (VFA) production, by use of an anaerobic manometric technique. Inhibitory effects of oils from the eight plant species may be placed in four groups: (i) essential oils from vinegar weed (
Trichostema lanceoletum
) and California bay (
Umbellularia californica
) inhibited rumen microbial activity most; (ii) lesser inhibition was exhibited by rosemary (
Rosmarinus officinalis
) and California mugwort (
Artemisia douglasiana
) oils, followed by (iii) blue-gum eucalyptus (
Eucalyptus globulus
) and sagebrush (
Artemisia tridentata
) oils; and (iv) oils from Douglas fir (
Psuedotsuga menziesii
) and Jerusalem oak (
chenopodium botrys
) resulted in the least inhibition, when 0.3 ml of each oil was used. A highly significant correlation coefficient (
r
= 0.98
**
) between total gas and VFA production indicated the validity of either method to measure the activity of rumen microorganisms. Our results are discussed in relation to the hypothesis that the selectivity and voluntary consumption of ruminants are related to the characteristic odor and antibacterial action of essential oils isolated from relatively unpalatable plant species.
Some Factors Influencing Carbon Dioxide Production by
Leuconostoc citrovorum
Authors: Holmes Beverly , Sandine W. E. , Elliker P. R.
Published: December 2020

This study was undertaken to determine whether
Leuconostoc citrovorum
plays a role in carbon dioxide production in milk. The ability of
L. citrovorum
strains to produce gas was studied by two methods. A qualitative method, in which an agar plug was forced up the neck of a volumetric flask, measured gas visually. This method demonstrated that 0.25% yeast extract, in a milk medium at 30 C, stimulated the production of at least 10 ml of gas. Studies using a Gilson Differential Respirometer revealed that
L. citrovorum
produced 500 to 900 μliters of CO
2
in 6.5 hr, whereas 800 to 1,500 μliters of CO
2
was produced in nonfat milk which contained 0.33% yeast extract. Cell extracts of
Streptococcus cremoris, S. lactis, Lactobacillus lactis, L. casei
, and
L. helveticus
also enhanced gas production of
L. citrovorum
from 20 to 70%. Autolysates of these bacteria, present during the ripening or ageing of certain cheeses, may stimulate
L. citrovorum
, a common organism in starter cultures, to produce gas, causing, for example, the slit-open defect of cheddar cheese. Yeast extract caused an increase in acid and gas production per cell but did not cause an increase in growth. Experiments indicated that one metabolic source of carbon dioxide was the decarboxylation of pyruvate produced during catabolism of citric acid. Yeast extract stimulated this reaction by 16%.
Improved Medium for Sporulation of
Clostridium perfringens
Authors: Duncan Charles L. , Strong Dorothy H.
Published: December 2020

An improved sporulation medium has been developed in which all five strains of
Clostridium perfringens
tested exhibited a 100- to 10,000-fold increase in numbers of spores when compared with spore yields in SEC medium under comparable conditions. In addition, three of five strains produced a 100- to 1,000-fold increase, with the remaining two strains yielding approximately the same numbers of spores, when compared with strains cultured in Ellner medium. At the 40-hr sampling time, 18 of 27 strains produced a 10- to 100-fold increase in numbers of spores in our medium, when compared to spore production obtained in a medium recently reported by Kim et al. The new medium contained yeast extract, 0.4%; proteose peptone, 1.5%; soluble starch, 0.4%; sodium thioglycolate, 0.1%; and Na
2
HPO
4
. 7H
2
O, 1.0%. In some cases, the spore yield could be increased by the addition of activated carbon to the new medium. The inclusion of activated carbon in the medium resulted in spores with slightly greater heat resistance than spores produced in the new medium without added carbon or in SEC or in Ellner medium. The major differences in heat resistance of the various strains appeared to be genetically determined rather than reflections of a particular sporulation medium. A definite heat-shock requirement was shown for four of four strains, with the optimal temperature ranging from 60 C for a heat-sensitive strain to 80 C for a heat-resistant strain. Heating for 20 min at the optimal temperature resulted in a 100-fold increase over the viable count obtained after heating for 20 min at 50 C.
Formation of Isoamylase by
Pseudomonas
Authors: Harada Tokuya , Yokobayashi Kozi , Misaki Akira
Published: December 2020

We have isolated a
Pseudomonas
sp. (strain SB15) which produces an isoamylase (EC 3.2.1.9). Highest yields of this enzyme were obtained when the bacterium was grown in shaken culture in a medium containing maltose, dextrin, starch, or isomaltose. Specific carbon and nitrogen sources were required for growth. The most satisfactory medium consisted of 2% maltose, 0.4% sodium glutamate, 0.3% diammonium hydrogen phosphate, and other inorganic salts. The optimal
p
H for enzyme production was 5 to 6. The enzyme is stable between
p
H 3 and 6 but is extremely labile above
p
H 7. It splits amylopectin completely by combined action with β-amylase but does not attack pullulan.
Differentiation of
Klebsiella-Enterobacter
(
Aerobacter
)-
Serratia
by Biochemical Tests and Antibiotic Susceptibility
Authors: Ramirez Manuel J.
Published: December 2020

Studies were undertaken for the differentiation of members of the
Klebsiella-Enterobacter
(
Aerobacter
)-
Serratia
division by biochemical tests and antibiotic susceptibility. A total of 67 cultures were tested. Strain identification was readily accomplished with the use of motility tests and arabinose fermentation. In addition, a practical schema, based on sensitivity pattern, proved valuable in the classification of the different strains. Most (if not all)
Klebsiella
strains were susceptible to cephalothin, and all were sensitive to colistin.
Enterobacter
strains were resistant to cephalothin but susceptible to colistin. In contrast to those other members of the group, all
Serratia
strains were resistant to both cephalothin and colistin. The combination of a limited number of biochemical reactions and single-disc sensitivity tests appears to be a logical approach for the tentative identification of
Klebsiella-Enterobacter
(
Aerobacter
)-
Serratia
strains.
Purine Analogue Sensitivity and Lipase Activity of Leptospires
Authors: Johnson Russell C. , Harris Virginia G.
Published: December 2020

The genus
Leptospira
can be divided into three groups based on purine analogue sensitivity and lipase (trioleinase) activity. Group 1 contains members of the “parasitic complex” of leptospires which initially cannot grow in media containing 10 μg of 2,6-diaminopurine (DAP) per ml or 200 μg of 8-azaguanine per ml. In addition, leptospires in this group possess lipase activity. Group 2 also contains members of the “parasitic complex” of leptospires. Although these leptospires are similarly sensitive to 8-azaguanine, they differ from group 1 leptospires in that they grow in media containing 10 μg of DAP per ml, and they do not possess detectable lipase activity. Group 3 consists of leptospires belonging to the “biflexa complex.” These leptospires are resistant to both purine analogues and have lipase activity.
Microtiter Indirect Hemagglutination Procedure for Identification of Streptococcal M-Protein Antibodies
Authors: Zimmerman Robert A. , Mathews James , Wilson Elizabeth
Published: December 2020

A number of investigators have attempted to utilize the hemagglutination system for detection of streptococcal type-specific antibody in human sera. Cross-reactions have made the procedure unreliable without cumbersome and time-consuming manipulation of the test sera. A method is described in which a microtiter indirect hemagglutination technique, using sensitized sheep erythrocytes, is sensitive, specific, and reliable for titration of type-specific antibody after naturally acquired or induced streptococcal infection.
Modified Biochemical Tests for Characterization of L-Phase Variants of Bacteria
Authors: Cohen Richard L. , Wittler Ruth G. , Faber John E.
Published: December 2020

Biochemical capabilities of bacterial and L-phase organisms of 15 bacterial strains were examined by using a variety of modified routine diagnostic biochemical tests. The results demonstrated that 13 of the tests examined were suitable for use with L-phase variants, that L-phase variants and revertant bacterial phase organisms retained diagnostically significant capabilities of the respective bacterial or L-phase organisms from which they were derived, and that the 13 biochemical tests could be usefully employed to relate a given L-phase variant to a given bacterial phase organism, to distinguish L-phase variants of different species, and to aid in the identification of nonreverting L-phase variants.
Starch Hydrolysis by Conidia of
Aspergillus wentii
Authors: Johnson D. E. , Nelson G. E. N. , Ciegler A.
Published: December 2020

Soluble starch was hydrolyzed to glucose by conidia of
Aspergillus wentii
NRRL 2001. Peak yields of glucose were achieved in 3 days. A glucoamylase-like enzyme was assumed to be responsible since maltose was not detected during the conversion. Spore age, storage conditions, and temperature affected the level of glucose accumulated. Iodoacetate inhibited catabolism of the glucose formed and this inhibition increased product yield. Spores of other fungi also hydrolyzed starch but none accumulated glucose naturally as did
A. wentii
spores.