bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Vancomycin on the Growth of Psittacosis-Trachoma Agents Cultivated in Eggs and Cell Culture
Authors: Jenkin Howard M. , Hung S. C.
Published: December 2020

The antibiotic vancomycin was effective in preventing bacterial contamination during studies with psittacosis and trachoma (PT) agents. This antibiotic was not toxic to chick embryos at 80 mg per egg, or to HeLa 229 cells cultivated in a medium containing 3,200 μg/ml of vancomycin; however, it was toxic to LLC-MK2 cells at a concentration of 1,600 μg/ml. Vancomycin did not affect the growth of a variety of PT agents at a concentration of 2 mg per egg or 800 μg per ml of cell culture medium, but it did inhibit the growth of common gram-positive bacterial air contaminants.
Culture Aeration in Polythermostat
Authors: Palumbo S. A. , Berry J. M. , Witter L. D.
Published: December 2020

A system for the aeration of cultures growing in a polythermostat temperature-gradient block was developed. This system provided both aeration and agitation of the cultures, while allowing the growth to be followed spectrophotometrically. The necessity for aeration of cultures growing in a polythermostat was experimentally shown.
Floc Sizing Techniques
Authors: Mueller J. A. , Morand J. , Boyle W. C.
Published: December 2020

In the study of mass transfer of substrate through floc particles, it is essential to have an estimate of floc size. This study presents floc size measurements made on pure culture bacterial floc and shows their applicability to mass transfer studies. A critical review of the biological literature on methods to size biological floc and determine wet floc density is also presented.
Copper Sulfide Precipitation by Yeasts from Acid Mine-Waters
Authors: Ehrlich H. L. , Fox Sally I.
Published: December 2020

Two strains of
Rhodotorula
and one of
Trichosporon
precipitated dissolved copper with H
2
S formed by reducing elemental sulfur with glucose. Iron stimulated this activity under certain conditions. In the case of
Rhodotorula
strain L, iron stimulated copper precipitation aerobically at a copper concentration of 18 but not 180 μg/ml. Anaerobically, the L strain required iron for precipitation of copper from a medium with 180 μg of copper per ml.
Rhodotorula
strain L was able to precipitate about five times as much copper anaerobically as aerobically. The precipitated copper was identified as copper sulfide, but its exact composition could not be ascertained. Iron was not precipitated by the H
2
S formed by any of the yeasts. Added as ferric iron, it was able to redissolve copper sulfide formed aerobically by
Rhodotorula
strain L from 18 but not 180 μg of copper per ml of medium. Since the yeasts were derived from acid mine-waters, their ability to precipitate copper may be of geomicrobial importance.
Aflatoxin-producing Potential of Isolates of the
Aspergillus flavus-oryzae
Group from Peanuts (
Arachis hypogaea
)
Authors: Taber Ruth A. , Schroeder Harry W.
Published: December 2020

Seventy-eight samples of farmer stock peanuts, representing peanuts grown in nine different geographical areas during 1964, were assayed for aflatoxin and examined for associated microflora. Only two samples contained more than 50 ppb of aflatoxin. Infestation by members of the
Aspergillus flavus-oryzae
group varied from 35 to 100% of the kernels per area and from 1 to 100% of the kernels per sample. Aflatoxin production by individual isolates ranged from 0 to 349,143 ppb under the test conditions employed. In general, the isolates produced 8 to 10 times more B
1
than B
2
, and no isolate producing aflatoxins G
1
or G
2
was found. The importance of proper postharvest handling of peanuts is emphasized by the prevalence of isolates of
A. flavus-oryzae
capable of producing aflatoxins on farmers stock peanuts.
Metabolism of Glycine by Rumen Microorganisms
Authors: Wright D. E. , Hungate R. E.
Published: December 2020

Rumen microorganisms rapidly metabolized glycine at rates varying from 0.014 to 0.241 μmole of glycine per ml per min. The main metabolic products were carbon dioxide, acetic acid, and ammonia; little glycine was incorporated into bacterial protein. Use of carboxyl or methylene-labeled glycine showed that the carbon dioxide came mainly from the carboxyl of glycine, whereas both carbons of acetic acid were derived partly from the methylene carbon of glycine and partly from carbon dioxide. The ratio of carbon-14 to nitrogen-15 in glycine isolated from the protein of rumen bacteria incubated in the presence of N
15
- and C
14
-labeled glycine indicated that most of the extracellular glycine incorporated into protein was incorporated without intervening deamination.
Occurrence of Zoogloea Colonies and Protozoans at Different Stages of Sewage Purification
Authors: Amin P. M. , Ganapati S. V.
Published: December 2020

The presence of fingered branch-bearing
Zoogloea
has been noted on a number of occasions in the Baroda Sewage Disposal Works. Samples of raw sewage, the effluent from the continuous flow settling basin, the raw sludge, the floating scum in the settling basin, the final secondary digested sludge, and the supernatant liquid from the secondary digester were kept without any disturbance in 1-liter Pyrex glass beakers, which were loosely covered with petri dishes. Scum was formed on the surface within 48 hr in all the samples, and fingered
Zoogloea
colonies resembling the pure culture of
Zoogloea ramigera
reported by Crabtree et al. (5) were found in all except the final secondary digested sludge and the supernatant liquid from the secondary digester. It is not known whether the
Zoogloea
colonies discovered in the above cases are the same as or different from the typical
Zoogloea ramigera
of activated sludge, and whether they are slime-forming or flocculent types of bacteria. In any case, they seem to be different in their ecological status and in the nature of the accompanying protozoans from the typical
Zoogloea ramigera
. The reasons for the absence of zoogloeas in two of the samples are unknown.
Influence of Platen Temperatures and Storage Conditions on the Survival of Freeze-dried
Salmonella typhimurium
Authors: Sinskey T. J. , Silverman G. J. , Goldblith S. A.
Published: December 2020

Salmonella typhimurium
survived freeze-drying at a platen temperature of 120 F (48.9 C) and also, though to a much lesser degree, at 160 F (82.6 C). The extent of the survival at these temperatures was dependent on the composition of the model system employed. The incidence of damage immediately after freeze-drying was greater for cells dried at the higher platen temperature and was influenced by the composition of the menstruum in which the cells were dried. In model systems having protein-dominant isotherms, survival during subsequent storage depended greatly on relative humidity, with recovery highest at relative humidities below those corresponding to moisture contents at which a monomolecular layer is formed. In menstrua having a higher sugar content, survival was best at low relative humidities corresponding to a very low equilibrium moisture content in the model system used. Damage during storage tended to be a function of the composition of the gels in which the organisms were freeze-dried, and also depended greatly on the presence of air and on the relative humidity. The maximal percentage of damage usually occurred at the low relative humidities as storage time increased.
Antibiotic Activity in the Presence of Agar
Authors: Hanus F. J. , Sands J. G. , Bennett E. O.
Published: December 2020

Agar has been shown to interfere with the activity of some antibiotics against
Staphylococcus aureus
. This interference has been observed as an increase in the minimal inhibitory concentration and in the diameter of the zone of inhibition. Purifying the agar with water extractions substantially reduced this adverse effect.
Influence of Relative Humidity on the Survival of Some Airborne Viruses
Authors: Songer Joseph R.
Published: December 2020

A system for studying the effects of relative humidity (RH) and temperature on biological aerosols, utilizing a modified toroid for a static aerosol chamber, is described. Studies were conducted at 23 C and at three RH levels (10, 35, and 90%) with four viruses (Newcastle disease virus, infectious bovine rhinotracheitis virus, vesicular stomatitis virus, and
Escherichia coli
B T3 bacteriophage). Virus loss on aerosol generation was consistently lower at 90% than at 10 or 35% RH. When stored at 23 C, Newcastle disease virus and vesicular stomatitis virus survived best at 10% RH. Infectious bovine rhinotracheitis virus and
E. coli
B T3 bacteriophage survived storage at 23 C best at 90% RH.
Lactobacilli in Ensiled High-Moisture Corn
Authors: Hesser James M. , Hartman Paul A. , Saul Robert A.
Published: December 2020

Aerobic mesophilic bacteria, molds, yeasts, and
Lactobacillus
species were enumerated at various intervals of the ensiling process of high-moisture corn (HMC). A total of 466 isolates of
Lactobacillus
were identified to determine the species of
Lactobacillus
associated with ensiled HMC and remoistened corn. The numbers of aerobic bacteria in the ensiled HMC increased to 10
8
per gram within 1 week and remained at this level throughout the storage period. The numbers of aerobic bacteria in the remoistened corn increased to 10
9
per gram and remained at this level during the 60-day storage period, after which they increased rapidly. Yeasts were the predominant microflora of the ensiled HMC. Mold numbers were low in the silos, but were very high in the remoistened corn, especially toward the end of the 60-day storage period. The species of
Lactobacillus
most frequently isolated from the ensiled HMC were
L. plantarum
, 52% of the isolates;
L. brevis
, 19% of the isolates;
L. brevis
(atypical), 15%;
L. fermenti
, 11%; and
L. buchneri
, 3%. The lactic acid bacteria, therefore, are the predominant bacterial flora of ensiled HMC, as they are of other types of plant forages that undergo similar fermentations.
Microtiter Hemagglutination-Inhibition Assay for Staphylococcal Enterotoxin B
Authors: Morse Stephen A. , Mah Robert A.
Published: December 2020

The rapid microtiter technique was investigated as a means of facilitating the detection of staphylococcal enterotoxin B. With this technique, many samples were assayed simultaneously, and readable results were obtained in 3 hr. Other advantages of this method, in addition to speed, were the small quantity of reactants used, ease of reading, and reproducibility.
Purification of the Kilham Rat Virus
Authors: Whitman James E. , Hetrick Frank M.
Published: December 2020

A purification procedure is described for the isolation of Kilham rat virus (RV) from infected suckling hamster kidney and liver suspensions. The procedure involved a combination of sonic treatment, differential centrifugation, butanol-chloroform extraction, agar column flow diffusion, and potassium tartrate density gradient centrifugation. The purified virus retained its infectivity and was specifically neutralized by RV hyperimmune antiserum. Electron micrographs from the RV band (density 1.31 g/ml) showed numerous homogeneous particles approximately 22 mμ in diameter.
Foam Separation of
Pseudomonas fluorescens
and
Bacillus subtilis
var.
niger
Authors: Grieves R. B. , Wang S. L.
Published: December 2020

An experimental investigation established the effect of the presence of inorganic salts on the foam separation of
Pseudomonas fluorescens
and of
Bacillus subtilis
var.
niger
(
B. globigii
) from aqueous suspension by use of a cationic surfactant. For
P. fluorescens
, 5.0 μeq/ml of NaCl, KCl, Na
2
SO
4
, K
2
SO
4
, CaCl
2
, CaSO
4
, MgCl
2
, or MgSO
4
produced increases in the cell concentration in the residual suspension (not carried into the foam) from 2.9 × 10
5
up to 1.6 × 10
6
to 2.8 × 10
7
cells per milliliter (initial suspensions contain from 3.3 × 10
7
to 4.8 × 10
7
cells per milliliter). The exceptional influence of magnesium was overcome by bringing the cells into contact first with the surfactant and then the salt. For
B. subtilis
, the presence of 5.0 μeq/ml of any of the eight salts increased the residual cell concentration by one order of magnitude from 1.2 × 10
4
to about 4.0 × 10
5
cells per milliliter. This occurred regardless of the sequence of contact as long as the surfactant contact period was sufficient. The presence of salts increased collapsed foam volumes with
P. fluorescens
and decreased collapsed foam volumes with
B. subtilis
.
Simple Medium for the Selective Isolation of
Bacteroides
and Related Organisms, and Their Occurrence in Sewage
Authors: Post F. J. , Allen A. D. , Reid T. C.
Published: December 2020

A medium composed of 0.009% sodium azide, 0.07% sodium deoxycholate, and 0.0007% ethyl violet in Brain Heart Infusion Agar (Difco) and a process of incubation in an atmosphere of 90% N
2
and 10% CO
2
for the selective isolation of certain members of the intestinal bacteroides are described. The medium appears to select predominantly members of the genus
Bacteroides
and a few of the genus
Sphaerophorus
. A survey of the occurrence of these organisms in sewage and various stages of sewage treatment indicates that they survive complete sewage treatment in low numbers and that their rate of decline parallels that of the coliforms. Large numbers were recovered from sludge digestion tanks, suggesting a possible role in the anaerobic breakdown of organic matter.
Dense Cultures of
Neisseria gonorrhoeae
in Liquid Medium
Authors: Brookes R. , Hedén C.-G.
Published: December 2020

Cultivation of
Neisseria gonorrhoeae
was effected in a conical glass culture vessel surrounded by a constant-temperature water jacket, and with facilities for stirring, aeration, and
p
H measurement and control. With the use of an aerated peptone-based medium, containing polypropylene glycol to prevent foam build-up, the yields obtained over the
p
H range from 5.8 to 7.4 were determined. The greatest yield was obtained at
p
H 6.4 when the dry weight was 1.5 g/liter. At
p
H 7.2 to 7.6, lysis was extensive.
Influence of
p
H on the Growth Characteristics of
Neisseria gonorrhoeae
in Continuous Culture
Authors: Brookes R. , Sikyta B.
Published: December 2020

A series of three continuous cultures of
Neisseria gonorrhoeae
was performed at
p
H values ranging from 6.4 to 7.2, with an average duration of 3 weeks. The maximal yield obtained was 1.12 mg/ml at a
p
H of 6.75 and a dilution rate of 0.26 per hr. Some morphological variations were observed at lower dilution rates, but complement-fixation titers remained stable for the duration of the cultures.
Method for Determining Antineuraminidase Activity
Authors: Wagner Roland B. , Steinberg Bernard A. , Ruchman Isaac
Published: December 2020

A test was developed to screen drugs for antineuraminidase (influenza sialidase) activity in vitro. Neuraminidase prepared from
Vibrio cholerae
was added to a substrate containing ganglioside, prepared from calf brain. Sialic acid is a split product in the reaction. The presence of sialic acid was detected colorimetrically by use of Warren's Thiobarbituric Acid Assay after drugs had been added to inhibit the action of neuraminidase on the calf brain substrate.
Modified Procedure for the Microscopic and Macroscopic Study of Viral Plaques
Authors: Soriano Federico , Cherry James D.
Published: December 2020

A virus plaque method that consistently gives good visual contrast for macroscopic observation and also permits microscopic study is described. Cells are grown in plastic flasks and the gelled overlay medium can be of any desired agar concentration or volume. A fixing solution is used prior to removal of the agar overlay, and dye is added to the fixing solution or staining can follow fixation and agar removal. The bottom of the flask with the fixed monolayer is separated from the rest of the container and handled as a slide. A new mounting medium is described.
Isolation and Purification of Staphylococcal Lipase
Authors: Vadehra D. V. , Harmon L. G.
Published: December 2020

An extracellular lipase was isolated from the cell-free supernatant fluid of a 24-hr culture of
Staphylococcus aureus
grown in Trypticase Soy Broth at 37 C with continuous agitation. The purification was achieved by precipitation with alcohol followed by differential precipitation at
p
H 8.6 and 4.3. Subsequent purification with Sephadex G 200 and BioGel 300 yielded a preparation which showed a 350- to 450-fold increase in specific activity over the original cell-free supernatant fluid. The purified lipase was homogeneous over a BioGel 300 column and showed a single peak on electrophoresis in a Veronal buffer (
p
H 8.6, Γ/2 = 0.1). The electrophoretic mobility was -7.78 × 10
-5
cm
2
per v per sec.
Pilot-Plant Production of Protease by
Alternaria tenuissima
Authors: Jönsson Arne G.
Published: December 2020

Agar slants of a selected
Alternaria tenuissima
strain were illuminated to give conidia suitable for further propagation. For production of protease with an optimal caseolytic activity in the region of
p
H 8 to 10, the fungus was cultivated in steel fermentors with 6- and 60-liter working capacity. Maximal activity, 1.5 enzyme units per liter, was attained in a medium based on liver after about 60 hr of cultivation. The protease was secreted parallel with, or slightly after, the main growth phase. The process could be run favorably with a relatively low aeration rate. The
p
H of the culture decreased during the process from 7.0 to about 6.3. This was the optimal region also when
p
H was kept constant by automatic
p
H control. Optimal temperature was about 28 C, which resulted in a maximal productivity of 0.057 enzyme units per liter per hr during the protease secretion phase. Replacement of the liver in the medium with skim milk, meat scrap, or rapeseed oil meal resulted in a decrease of the protease yield.
Milky Disease Bacteria
Authors: Steinkraus K. H. , Tashiro H.
Published: December 2020

A comparative study was made of all available milky-disease species and strains that have been isolated around the world from beetle larvae (family
Scarabaeidae
). Included in the study were
Bacillus popilliae
Dutky,
B. lentimorbus
Dutky, and
B. lentimorbus
var.
maryland
from the United States;
B. euloomarahae
Beard and
B. lentimorbus
var.
australis
Beard from Australia;
B. fribourgensis
Wille from Switzerland; and New Zealand milky disease (Dumbleton). The organisms were classified into three groups: (i) those containing parasporal bodies, including
B. popilliae
Dutky,
B. fribourgensis
Wille, and New Zealand milky disease (Dumbleton); (ii) those without a visible parasporal body and with spore morphology similar to
B. lentimorbus
Dutky, including
B. lentimorbus
var.
australis
Beard; and (iii) those with very tiny spores and no parasporal body, including
B. euloomarahae
Beard and
B. lentimorbus
var.
maryland
. All available milky-disease species and strains were cultivated in vitro on Brain Heart Infusion Agar plates. However, the most fastidious organisms—
B. euloomarahae
and
B. lentimorbus
var.
maryland
—could not be grown until they were passed through a life cycle in larvae of a large scarabaeid beetle infesting rotting wood. Then they remained stable for only one or two subcultures. All the milky-disease organisms produced larger cells in vitro than they did in vivo. The pattern of sugar fermentations was similar for all milky-disease species. It appears that there is a very low percentage of strains of
B. popilliae, B. lentimorbus
, and the other milky-disease organisms that have the inherent genetic makeup to permit them to sporulate on artificial media, if conditions are favorable. Among these conditions are a sufficiently high cell population and a reduced oxygen tension. Spores produced in vitro may have a low virulence via the normal ingestion pathway, even though they show apparent virulence when injected directly into the hemocoel.
Dose Response Curve Linearization and Computer Potency Calculation of Turbidimetric Microbiological Vitamin Assays
Authors: Tsuji Kiyochi , Elfring G. L. , Crain H. H. , Cole R. J.
Published: December 2020

The dose response curves of various turbidimetric microbiological assays, including vitamin B
12
, Ca pantothenate, and pyridoxine (vitamin B
6
), were linear with logarithmic transformation of the responses by use of the equation derived,
ln
[
T
(
x
) -
T
(∞)] =
ln A - Bx
. A Fortran computer program which used the slope ratio potency calculation was written. The assay potencies calculated by the computer program showed excellent agreement with those obtained by the manual calculation.
Identification of Microorganisms Isolated from Jet Fuel Systems
Authors: Edmonds Paul , Cooney J. J.
Published: December 2020

Seventy-two samples from jet aircraft fuel systems were examined for microbial contamination. Ten contaminated samples yielded 43 microorganisms which were classified into nine genera of bacteria and three genera of fungi. The predominant types, comprising about 37% of the isolated cultures, were identified as
Bacillus
spp. The remaining cultures were distributed among 11 genera, each of which represented 2 to 9% of the total isolates. Four cultures could not be assigned to a genus on the basis of the diagnostic criteria used. Only five isolates, in the genera
Pseudomonas
and
Hormodendrum
(
Cladosporium
), grew abundantly in a mineral salts solution with JP-4 fuel as the sole source of carbon. The presence of fuel utilizers in a fuel system may be a better index to potential problems that have been correlated with microbial contamination than the presence of aerobic sporeforming bacilli.
Aerobic Heterotrophic Bacterial Populations of Sewage and Activated Sludge
Authors: Prakasam T. B. S. , Dondero Norman C.
Published: December 2020

Agar plating media containing solely activated sludge extracts yielded, in general, higher viable counts of activated sludge bacteria than any other culture medium tested. Activated sludge extracts made from different treatment plants varied in efficacy in evoking maximal viable counts. Frequently, homologous plating, i.e., plating inocula of activated sludges on extracts made from the same activated sludges, tended to yield lower counts than the heterologous platings tried in this investigation. The counts obtained by homologous plating of activated sludge were not significantly lower and sometimes were even significantly higher than the counts obtained on standard Nutrient Agar, which had been found by previous workers to be a good medium for counting activated sludge bacteria. The higher counts obtained with activated sludge extracts set objectives for formulating reproducible or defined culture media for the enumeration of activated sludge bacteria.
Resistivity of Spores to Ultraviolet and γ Radiation while Exposed to Ultrahigh Vacuum or at Atmospheric Pressure
Authors: Silverman Gerald J. , Davis Norman S. , Beecher Norman
Published: December 2020

Viability studies were conducted on microbial spores subjected to ultrahigh vacuum (UHV) in the 10
-9
to 10
-10
torr range. After 5 to 7 days in vacuum, they were exposed to ultraviolet (UV) or to γ radiation either while still under vacuum or in the presence of dried air. Among the four test organisms subjected to UHV and ultraviolet radiation,
Aspergillus niger
was the most resistant;
Bacillus megaterium, B. subtilis
var.
niger
, and
B. stearothermophilus
were about equally less resistant. All four spores were more sensitive to ultraviolet radiation when UHV-dried than when desiccant-dried. Of the four test organisms subjected to UHV and γ radiation,
B. megaterium
proved to be the most resistant;
A. niger
was the least resistant; and the remaining two organisms were of intermediate resistivity. All four organisms were less radiation resistant when UHV-dried than when irradiated in their normally hydrated state, and all showed an increased radiosensitivity after vacuum drying when oxygen was present. In addition, spores of
B. subtilis
var.
niger
and
A. niger
were less radiosensitive when UHV-dried and irradiated in vacuum than when “wet” and irradiated in air, whereas the reverse relationship was observed for the remaining two organisms. Based on the fact that microbial contaminants can be readily shielded from UV light by soils, metal particles, etc., and considering that the levels of ionizing radiations reported to be present in interstellar space are generally lower than those used in these experiments, the decrease in radioresistivity imparted by UHV drying is not of a sufficient magnitude to sterilize dependably portions of a spacecraft while on a mission.
Inactivation of Adenovirus and Simian Virus 40 Tumorigenicity in Hamsters by Vaccine Processing Methods
Authors: Truffelli G. T. , Timm E. A. , Beardmore W. B. , Mclean I. W.
Published: December 2020

The effectiveness of the adenovirus vaccine inactivation process in destroying the tumorigenic potential for hamsters of adenoviruses, simian virus 40 (SV-40), and adenovirus-SV-40 hybrids was studied. Baby hamsters injected with untreated virus and with samples subjected to the complete inactivation process and to portions of the process were observed for tumor development for periods in excess of 300 days. Over 20,000 hamsters were injected. From 1 to 7 hr of exposure to formaldehyde at a concentration of 0.031
m
at 37 C was sufficient to destroy the tumorigenicity observed in the nontreated preparations. Since the inactivation process included 48 hr of exposure at 37 C to 0.031
m
formaldehyde plus treatment with ultraviolet (UV) and with β-propiolactone (BPL), it was concluded that the process has a large margin of safety. Adenovirus isolates free from tumorigenic potential are difficult, if not impossible, to obtain. Therefore, a proven inactivation process appears to provide the best assurance for obtaining adenovirus vaccines free from such potential. Data presented suggest that the tumorigenic property of the viruses studied might be independent of the infectivity of the preparation. The tumorigenic property was found to be highly susceptible to formaldehyde, but less sensitive to BPL or UV treatment. In contrast, treatment with UV or BPL decreased viral infectivity more readily than tumorigenicity. The three-stage inactivation process (formaldehyde, UV, and BPL) inactivated both tumorigenicity and infectivity.
Isolation of the Bromo Analogue of Caldariomycin from
Caldariomyces fumago
Authors: Patterson E. L. , Andres W. W. , Mitscher L. A.
Published: December 2020

When bromide ion was substituted for chloride in the growth medium of
Caldariomyces fumago
, a new substance was produced. It was isolated by solvent extraction and purified by alumina chromatography. Examination of the physicochemical properties of the substance led to its identification as the bromo analogue of the normal metabolite, caldariomycin. Thus, biological substitution of bromine for chlorine has been demonstrated in the metabolic formation of a purely aliphatic secondary mold metabolite.
Improved Assay Method for Phospholipase C
Authors: Kurioka Susumu , Liu Pinghui V.
Published: December 2020

A lecithin sol dispersed with deoxycholate was found to be attacked by phospholipase C in the presence of calcium ion more rapidly than were any other lecithin sols. The inorganic phosphate could be released quantitatively from the acid soluble phosphate liberated from lecithin by an excess amount of alkaline phosphatase present in phospholipase C reaction mixture. A simple and accurate assay method for phospholipase C was developed with the sol and the alkaline phosphatase.
Quantitative Bacteriological Analysis of Sputum as a Test of Antibiotic Efficacy
Authors: Lorian Victor , Khavari Paris , Gray Nancy
Published: December 2020

After 5 days of treatment, sputa were analyzed from 40 patients treated with sodium fusidate and 20 patients treated with naficillin. There was a significant decrease in the number of staphylococci, but no significant change in the other flora. The quantitative bacteriological analysis of sputum specimens proved to be a useful laboratory procedure for providing information on the in vivo effectiveness of specific antibacterial therapy in respiratory infections.
Effect of Imput Multiplicity and Tissue Cell Concentration on Growth of Rift Valley Fever Virus
Authors: Orlando Michael D. , DeLauter Richard D. , Riley Jean M.
Published: December 2020

The effects of virus input multiplicity and of tissue cell concentration upon the growth of Rift Valley fever virus in L cells (Earle) were determined. The titers obtained in suspension cultures with cells obtained from two separate laboratories were significantly different. With both monolayer culture and suspension culture systems, a virus input multiplicity of 2.5 resulted in the greatest proliferation of virus. Optimal viral yields were obtained in suspension cultures containing 4 × 10
5
tissue cells per ml of suspension.
Ergotamine Production in Submerged Culture and Physiology of
Claviceps purpurea
Authors: Amici Alba M. , Minghetti A. , Scotti T. , Spalla C. , Tognoli L.
Published: December 2020

Strain 275 FI of
Claviceps purpurea
, which produces large amounts of peptide alkaloids in submerged culture, and strains V, C, and W, spontaneously obtained from 275 FI and practically unable to produce alkaloids, were compared. Strain 275 FI differs from the other strains in its capacity to accumulate lipids and sterols, as well as in its capacity to produce alkaloids. Strain 275 FI utilizes large quantities of sucrose and citric acid simultaneously; strain V utilizes large amounts of sucrose but little citric acid; strain C utilizes large quantities of citric acid but only small amounts of sucrose; strain W consumes only small amounts of both substances. We conclude that the production of large quantities of alkaloids, as well as the accumulation of lipids and sterols, is correlated with the simultaneous utilization of large amounts of sucrose and citric acid.
Microflora of Black and Red Pepper
Authors: Christensen C. M. , Fanse H. A. , Nelson G. H. , Bates Fern , Mirocha C. J.
Published: December 2020

Dilution cultures of 30 samples of ground black pepper yielded an average of 39,000 colonies of fungi per g, with a range of 1,700 to 310,000 per g. Total numbers of colonies of bacteria from 11 samples averaged 194,000,000 per g, with a range from 8,300,000 to 704,000,000 per g. A variety of fungi grew from nearly all surface-disinfected whole peppercorns that were cultured. Thirteen samples of ground red pepper from the United States yielded an average of 1,600 colonies of storage fungi per g and an equal number of other fungi; five samples from India yielded an average of 78,900 colonies of storage fungi per g and 169,400 colonies of other fungi per g. Among the fungi from both black and red pepper were
Aspergillus flavus
and
A. ochraceus
, some isolates of which, when grown for 8 to 10 days on moist autoclaved corn and fed to white rats or to 2-day-old Pekin ducklings, were rapidly lethal to them. Aflatoxin B
1
was isolated from one of the samples of corn on which
A. flavus
from black pepper was grown. Among the bacteria isolated from ground black pepper were
Escherichia coli, E. freudii, Serratia
sp.,
Klebsiella
sp.,
Bacillus
sp.,
Staphylococcus
sp., and
Streptococcus
sp. No cultures of
Shigella
or
Salmonella
were found.
Enumeration of
Bacillus cereus
in Foods
Authors: Mossel D. A. A. , Koopman M. J. , Jongerius E.
Published: December 2020

For the enumeration of vegetative cells and spores of
Bacillus cereus
in foods, a mannitol-egg yolk-phenol red-agar has been developed which exploits the failure of
B. cereus
to dissimilate mannitol, and the ability of most strains to produce phospholipase C. When a high degree of selectivity was required, polymyxin B sulfate in a concentration of 10 ppm appeared to be the most effective selective additive. Useful characteristics for the identification of presumptive isolates of
B. cereus
were found to be: morphology, dissimilation of glucose mostly to acetyl methyl carbinol under anaerobic conditions, hydrolysis of starch and gelatin, reduction of nitrate, and growth on 0.25% chloral hydrate agar.
Bacteriology of Spoilage of Fish Muscle
Authors: Lerke Peter , Farber Lionel , Adams Ralph
Published: December 2020

Clarified muscle press juice from English sole (
Parophrys vetulus
) was fractionated by gel filtration into a protein and a protein-free fraction. Upon inoculation with spoilage bacteria, the protein fraction failed to show any signs of spoilage, but the protein-free fraction spoiled according to the usual organoleptic and chemical criteria. Despite its spoilage-resistant qualities, the protein fraction accelerated spoilage of the protein-free fraction when the two were combined. Protein breadkown due to bacterial action was greatest in the unfractionated juice and was least in the protein fraction. No significant proteolysis occurred until after spoilage became evident.
Effects of Continuous and Interrupted Radiation on Microorganisms
Authors: Borick P. M. , Fogarty M. G.
Published: December 2020

Various bacterial spores exhibited a wide range of radiation resistance to doses of 0.25 to 2.5 Mrad from a cobalt-60 radiation facility.
Bacillus pumilus
and Clos-
tridium tetani
were shown to have the highest degree of resistance when compared with other bacterial sporeformers.
B. subtilis
E163 was the least resistant of the bacterial spores studied. Dried spores contained on cellulose discs were more readily destroyed by γ-rays than were wet spores under similar conditions.
Mycobacterium tuberculosis
was destroyed by radiation doses much lower than that required by the least resistant bacterial spores. Interrupted dosimetry tests performed with materials of various types showed that sutures and other similar materials were effectively sterilized when the total radiation dose was given in two separate exposures with periods of interruption of 1 to 19 days. When “agar dosimeters” were employed in similar interrupted dosimetry series,
B. pumilus
spores were recovered in a few tests after administration of a total combined dosage of 2.5 Mrad with interruption periods of 2 to 19 days. When the experiment was repeated with interruption for 14 days, no survivors were found after a total dose of 2.0 to 2.8 Mrad.
Chemical Determination of Leucogenenol and Its Production by
Penicillium gilmanii
Authors: Rice F. A. H. , Barrow Meredith
Published: December 2020

A method for the quantitative determination of leucogenenol, a leucocytosis-inducing compound produced by
Penicillium gilmanii
, has been developed. The formation of leucogenenol in
P. gilmanii
and its diffusion into the culture fluid has been followed over a period of 12 weeks. The highest concentration of leucogenenol was found in the mycelium of rapidly growing cultures. The greatest concentration occurred in the culture fluid, however, after cessation of rapid growth. The concentration of leucogenenol in the mycelium of cultures over 4 weeks old fluctuated widely. This fluctuation was apparently due to the formation and rapid growth of daughter colonies.
Certification of Probability of Sterilization of Liquid by Filtration
Authors: Portner Dorothy M. , Phillips Charles R. , Hoffman Robert K.
Published: December 2020

Four types of hydrosol filters, two reusable (diatomaceous cylinder and fritted-glass funnel) and two disposable (asbestos pad and membrane filter) were challenged with a heavy bacterial suspension to assess their ability to produce sterile filtrates. Two of the four diatomaceous earth filters, the four fritted-glass funnels, and all of the asbestos pads tested generally gave sterile filtrates. However, only one type of filter, one of the membranes in its manufacturer's own holder, consistently gave sterile filtrates. The two other types of membranes usually gave sterile filtrates if tested in one manufacturer's holder, but all types invariably gave contaminated filtrates when tested in another manufacturer's holder. Contaminated filtrates were generally attributed to a poor reusable filter or to a faulty holder used with a disposable filter. If a high degree of certainty is required for sterile heat-labile filtrate, it is suggested that the liquid be passed through two or more filters in a previously tested and proven system.
Etiology of Bacteremia
Authors: Dalton Harry P. , Allison Marvin J.
Published: December 2020

Blood-culture results for a 15-year period from a large southern hospital were tabulated and analyzed for alterations in the bacterial species associated with bacteremia. From 15,543 cultures, 2,410 positive cultures (15.6%) were obtained. These results were grouped into 5-year periods, and an alteration in the incidence of the agents was demonstrated. In the past 5 years, gram-negative bacilli have replaced gram-positive cocci as the most common agents of bacteremia, and several species not formerly associated with septicemia were found to be involved in a large number of cases. The importance of the clinical laboratory monitoring blood culture results was demonstrated as was the need for constant collaboration between the clinician and microbiologist.
Aminopeptidase Profiles of Various Bacteria
Authors: Westley J. W. , Anderson P. J. , Close V. A. , Halpern B. , Lederberg E. M.
Published: December 2020

The aminopeptidase specificity of 24 strains of bacteria was determined fluorometrically by use of a series of α-amino acid β-naphthylamides as substrates. Provided that strict control over medium and growth time was adhered to, a reproducible profile of aminopeptidase activity was obtained which could be used for the identification of bacteria.
Lipid Patterns of Selected Microorganisms as Determined by Gas-Liquid Chromatography
Authors: Steinhauer John E. , Flentge Robert L. , Lechowich Richard V.
Published: December 2020

The cellular lipid patterns of seven strains of microorganisms were examined by gas-liquid chromatography in this preliminary study. The chloroform methanol-soluble lipids were extracted by the Soxhlet method from dried cultures which had been grown at 25 ± 2 C for 18 hr with mechanical shaking. The cellular extract was methylated by use of a low temperature sulfuric acid method, and the resulting methyl esters were chromatographed. Considerable differences in the lipid patterns among the seven microorganisms tested indicated that this method might be useful for the identification of closely related microbial genera, and possibly for species differentiation.
Preparation of
14
C-labeled Tuberculin Purified Protein Derivative
Authors: Landi S. , Held H. R. , Hauschild A. H. W. , Hilsheimer R.
Published: December 2020

14
C-labeled tuberculin purified protein derivative (
14
C-tuberculin PPD) has been prepared from culture filtrates of
Mycobacterium tuberculosis
var.
hominis
grown in a culture medium containing uniformly labeled
14
C-amino acids. With a mixture of
14
C-amino acids (an acid hydrolysate of
14
C-
Chlorella
protein) in the medium, the recoveries of
14
C in the final product were higher than with
14
C-labeled-
l
-glutamic acid.
14
C-tuberculin PPD was separated into tuberculoprotein and nucleic acid by paper electrophoresis. The specific radioactivity of tuberculoprotein was substantially greater than that of the nucleic acid.
14
C-tuberculin PPD is advocated as a means to measure the adsorption of tuberculin to glass or other surfaces. It could also prove useful as a means to study the structure and mode of action of tuberculin.
Stimulation of Yield in the Cultivated Mushroom by Vegetable Oils
Authors: Schisler Lee C.
Published: December 2020

Supplementation of mushroom compost at spawning and at casing with various refined and crude seed oils resulted in 1 to 1.5 lb/ft
2
increases in mushroom yield. Supplementation at casing with ground seeds or protein-oil combinations caused 2 to 2.5 lb/ft
2
increases in mushroom yield. Further evidence is presented for a relationship between lipid metabolism and the initiation of fruiting in the cultivated mushroom,
Agaricus bisporus
(Lange) Sing. Preliminary results suggest the possible involvement of sterols in the fruiting stimulation.
Proteinase Enzyme System of Lactic Streptococci
Authors: Cowman R. A. , Speck M. L.
Published: December 2020

Proteinase activity of
Streptococcus lactis
cells was maximal at
p
H 6.0, but after storage at 3 C the minimal activity was observed at this
p
H. Activity lost as a result of storage could be restored by adding glutathione. Whole cells were fractionated into soluble (intracellular) and particulate fractions by sonic disruption; both fractions contained enzymatic activity. Activity of the soluble (intracellular) fraction was found to be stable to storage at 3 C, but was inhibited progressively with increasing concentrations of
p
-hydroxymercuribenzoate (PHMB). The enzymatic activity of this fraction was not activated by ferrous or magnesium ions or by cysteine. In contrast, activity of the particulate fraction was labile to storage at 3 C, and the reduction was comparable to that of stored cells. Furthermore, proteinase activity in the cells and the particulate fraction was not affected by addition of PHMB. The particulate fraction was activated by ferrous and magnesium ions and by cysteine. After storage, only ferrous ion and cysteine promoted reactivation; magnesium ion was totally ineffective. The enzyme(s) contained in the particulate fraction may be involved in decreased proteinase activity observed in whole cells and in the effect on growth of cells after storage.
Microbial Hydrocarbon Co-oxidation
Authors: Raymond R. L. , Jamison V. W. , Hudson J. O.
Published: December 2020

Nocardia
cultures, isolated from soil by use of
n
-paraffins as the sole carbon source, have been shown to bring about significant oxidation of several methyl-substituted mono- and dicyclic aromatic hydrocarbons. Oxygen uptake by washed cell suspensions was not a reliable indicator of oxidation. Under co-oxidation conditions in shaken flasks,
o
- and
p
-xylenes were oxidized to their respective mono-aromatic acids,
o
-toluic and
p
-toluic acids. In addition, a new fermentation product, 2, 3-dihydroxy-
p
-toluic acid, was found in the
p
-xylene oxidation system. Of 10 methyl-substituted naphthalenes tested (1-methyl, 2-methyl, 1, 3-dimethyl, 1, 4-dimethyl, 1, 5-dimethyl, 1, 8-dimethyl, 1, 6-dimethyl, 2, 3-dimethyl, 2, 6-dimethyl, 2, 7-dimethyl), only those containing a methyl group in the β position were oxidized at this position to the mono acid.
Nutritional Requirements of
Staphylococcus aureus
S-6
Authors: Mah Robert A. , Fung Daniel Y. C. , Morse Stephen A.
Published: December 2020

A synthetic medium was devised for growth of
Staphylococcus aureus
strain S-6. The growth yield in synthetic medium was compared to that in complex medium containing an equivalent amount of protein hydrolysate. Enterotoxin B formation in the two media was also compared. The defined medium was composed of inorganic salts, 11 amino acids (glycine, valine, leucine, threonine, phenylalanine, tyrosine, cysteine, methionine, proline, arginine, and histidine), and three vitamins (thiamine, nicotinic acid, and biotin). Biotin was a growth factor requirement of S-6 when glutamic acid but not glucose was used as a carbon source. The quantity of enterotoxin B produced in the defined medium was about one-seventh of that produced in complex medium, even though the growth yields were similar.
Demonstration and Isolation of
Clostridium botulinum
Types from Whitefish Chubs Collected at Fish Smoking Plants of the Milwaukee Area
Authors: Pace P. J. , Krumbiegel E. R. , Angelotti R. , Wisniewski H. J.
Published: December 2020

A total of 1,071 whitefish chub samples were examined at eight stages of processing, including sampling aboard ship, various processing steps in the smoking plant, and display in retail cases. The frequency of
Clostridium botulinum
contamination of freshly caught and eviscerated chubs was approximately 13 to 14%. The highest percentage of contamination (20%) was noted among chubs sampled at the brining step of processing. The prevalence of contamination among chubs sampled at other processing stages prior to the smoking operation ranged from 6 to 14%. Of 858 freshly smoked chubs that had been processed at 180 F for 30 min (internal temperature of loin muscle), 10 were contaminated with
C. botulinum
(1 Type B and 9 Type E). The use of heat-shocked (60 C for 15 min) and nonheat-shocked enrichment cultures in combination yielded a greater number of positive samples than either method yielded when used alone. Each toxic enrichment culture obtained was subcultured to obtain isolation of the toxigenic organism. Toxigenic pure cultures of
C. botulinum
were obtained from 80% of the fish samples observed to produce toxic enrichment cultures.
Quantitative Studies on Fabrics as Disseminators of Viruses
Authors: Sidwell Robert W. , Dixon Glen J. , Mcneil Ethel
Published: December 2020

Eight compounds were tested in vitro for virucidal and antiviral activity against poliovirus and vaccinia virus. These compounds included five quaternary ammonium salts, two bromosalicylanilides, and neomycin sulfate, an antibiotic. None of the compounds was active against poliovirus, but virucidal activity was demonstrated against vaccinia virus with three of the quarternary ammonium compounds:
n
-alkyl (C14, C12, C16) dimethyl benzyl ammonium chloride, di-isobutyl cresoxy ethoxy ethyl dimethyl benzyl ammonium chloride monohydrate, and
n
-alkyl (60% C14, 30% C16, 5% C12, 5% C18) dimethyl benzyl ammonium chlorides plus
n
-alkyl (50% C12, 30% C14, 17% C16, 3% C18) dimethyl ethylbenzyl ammonium chlorides. Wool blanketing, wool gabardine, and cotton sheeting materials were impregnated with the first of the above virucidal compounds, and the persistence of vaccinia virus on these fabrics was compared with the persistence of the agent on nonimpregnated fabrics of the same type held at 25 C in 35 and 78% relative humidity. No virus could be recovered from the chemically treated fabrics at any time after virus exposure, whereas the virus persisted as long as 4 weeks on nonimpregnated materials. Viable vaccinia virus was also found to persist less than 1 day on a cotton fabric finished with a wash-and-wear modified triazone resin. Poliovirus persisted less than 5 days on this wash-and-wear fabric.
LL-A491, A Monazomycin-like Antibiotic
Authors: Mitscher Lester A. , Shay Anthony J. , Bohonos Nestor
Published: December 2020

A new antibiotic, designated LL-A491, was isolated by butanol extraction and crystallization from beers of an unidentified streptomycete, Lederle culture A491. LL-A491 was primarily active against gram-positive bacteria and was related to monazomycin. A tentative molecular formula of C
72�2
H
144�8
O
25�1
N for the antibiotic, based on analyses of the crystalline hydrochloride, picrate, and picrolonate salts, is considerably larger than that proposed for monazomycin, from which LL-A491 was not differentiated by paper chromatography. Analysis of the amorphous polyacetate ester suggested 15 to 16 acetylable groups. Upon hydrolysis, LL-A491 liberated ammonia and a reducing sugar which appeared to be mannose. LL-A491 was dextrorotatory, [α]
D
25
+ 14�, and exhibited only end absorption in the ultraviolet region.
Aflatoxin Production by
Aspergillus flavus
as Related to Various Temperatures
Authors: Schindler A. F. , Palmer John G. , Eisenberg W. V.
Published: December 2020

Two aflatoxin-producing isolates of
Aspergillus flavus
were grown for 5 days on Wort media at 2, 7, 13, 18, 24, 29, 35, 41, 46, and 52 C. Maximal production of aflatoxins occurred at 24 C. Maximal growth of
A. flavus
isolates occurred at 29 and 35 C. The ratio of the production of aflatoxin B
1
to aflatoxin G
1
varied with temperature. Aflatoxin production was not related to growth rate of
A. flavus
; one isolate at 41 C, at almost maximal growth of
A. flavus
, produced no aflatoxins. At 5 days, no aflatoxins were produced at temperatures lower than 18 C or higher than 35 C. Color of CHCl
3
extracts appeared to be directly correlated with aflatoxin concentrations.
A. flavus
isolates grown at 2, 7, and 41 C for 12 weeks produced no aflatoxins. At 13 C, both isolates produced aflatoxins in 3 weeks, and one isolate produced increasing amounts with time. The second isolate produced increasing amounts through 6 weeks, but at 12 weeks smaller amounts of aflatoxins were recovered than at 6 weeks.