bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Macroscopic Examination, Routine Gram Stains, and Routine Subcultures in the Initial Detection of Positive Blood Cultures
Authors: Blazevic Donna J. , Stemper Joanne E. , Matsen John M.
Published: December 2020

Blood was cultured in two vaccum bottles containing Columbia broth with sodium polyanethol sulfonate and CO
2
. Filtered air was admitted to one bottle, and the bottles were incubated at 35 C until growth was detected or for a maximum of 7 days. Bottles were examined daily for macroscopic growth. Gram stains were made routinely on the 1st, 4th, and 7th days, and samples were routinely subcultured to sheep blood agar (incubated in GasPak jar) and chocolate agar (incubated in CO
2
) on the 1st and 4th days of incubation. Of 1,127 positive blood cultures, 65% were first detected by macroscopic examination, 23% were first detected by Gram stain, and 12% were first detected only by subculture.
Methods for Detecting Indole Production by Gram-Negative Nonsporeforming Anaerobes
Authors: Fay Gunnar D. , Barry Arthur L.
Published: December 2020

To help select the most appropriate method for detecting indole production with anaerobic gram-negative bacilli, several recommended methods were compared. Indole was measured both quantitatively and qualitatively after varying periods of incubation. Studies evaluated the results obtained in different media, the effect of adding glucose and/or tryptophan, the requirement for strict anaerobiasis, and the effects of reducing the total volume of broth. A 1-ml amount of thioglycolate broth without glucose but with 0.02% tryptophan gave optimal results after 2 to 7 days of incubation in anaerobic (Gas-Pak) jars. The majority of clinical isolates will give strong positive tests after 1 to 2 days but a few require 3 to 7 days of incubation. Prolonged incubation was required more frequently with conventional methods.
Scanning Electron Microscope Study of
Neisseria gonorrhoeae
Authors: Kraus Stephen J. , Glassman Lawrence H.
Published: December 2020

Morphological studies utilizing various microscopy techniques have aided in our understanding of the gonococcus and gonorrhea. In this study scanning electron microscopy was used to study differences in virulent (colony types 1 and 2) and avirulent (colony types 3 and 4) gonococci relative to colony appearance, patterns of growth in liquid media, and surface features of individual cocci. Colony types of virulent gonococci are smaller in diameter but have a higher evaluation than those of avirulent mutants. Colony type 2 has a convex undersurface that is associated with surface pitting of solid media. When the colonies are grown in liquid media, various degrees of autoagglutination are observed; this is most pronounced with type 2 and least evident with type 4. Although pili may be involved in this phenomena, other mechanisms must be employed, since type 3 gonococci that lack pili autoagglutinate. Pili are seen on types 1 and 2 and are absent from types 3 and 4. They appear as individual threads radiating from the bacteria or as bundles of pili attaching adjacent cocci. Another extracellular structure consists of small spherical bodies that can coat the bacteria surface, attach to pili, or exist free from other bacterial components. These spheres are least evident with type 4. The gonococcal surface is pebbly with multiple sulci.
Immunofluorescent Cell Assay of Infectious Pancreatic Necrosis Virus
Authors: Tu Kuen-Ching , Spendlove Rex S. , Goede Ron W.
Published: December 2020

An immunofluorescent cell (IFC) assay technique was developed for the quantification of infectious pancreatic necrosis (IPN) virus of salmonid fishes. Cover slip cultures of rainbow trout gonad (RTG-2) cells were infected with diluted virus preparations. After incubation to permit antigen development, the cells were stained with antiviral fluorescent antibody, and the number of fluorescing (infected) cells was counted. Optimal conditions for the IFC assay procedure are: (i) the use of RTG-2 cells cultured for at least 3 days at 20 C; (ii) 1-h absorption of IPN virus to RTG-2 cells at 20 C or alternatively, 4 h at 4 C; (iii) staining the infected cell cultures at 10 to 12 h postinfection. A linear relationship between the relative concentration of virus in the inoculum and the number of fluorescent cells in the first cycle of infection was observed. The IFC assay method is more sensitive than the plaque method for the assay of IPN virus.
Diurnal Variations of Nitrogenase Activity in the Field
Authors: Balandreau J. P. , Millier C. R. , Dommergues Y. R.
Published: December 2020

Nitrogenase activity was determined in situ by repeated assays at regular intervals to compare the patterns of diurnal variations occurring in a rice field, a grassland, and a peanut field. In the rice field only one peak occurred (mid-day), whereas the other systems exhibited typical two-peak patterns, which were suspected to be induced by climatic conditions or possibly by a specific rhythm of exudation. Observed data on diurnal variations in nitrogenase activity were fitted to different models of diurnal variation comprised of computed periodic curves.
Mathematical Estimation of the Level of Microbial Contamination on Spacecraft Surfaces by Volumetric Air Sampling
Authors: Oxborrow G. S. , Roark A. L. , Fields N. D. , Puleo J. R.
Published: December 2020

Microbiological sampling methods presently used for enumeration of microorganisms on spacecraft surfaces require contact with easily damaged components. Estimation of viable particles on surfaces using air sampling methods in conjunction with a mathematical model would be desirable. Parameters necessary for the mathematical model are the effect of angled surfaces on viable particle collection and the number of viable cells per viable particle. Deposition of viable particles on angled surfaces closely followed a cosine function, and the number of viable cells per viable particle was consistent with a Poisson distribution. Other parameters considered by the mathematical model included deposition rate and fractional removal per unit time. A close nonlinear correlation between volumetric air sampling and airborne fallout on surfaces was established with all fallout data points falling within the 95% confidence limits as determined by the mathematical model.
Relationship of Cellular Fatty Acid Composition to Survival of
Lactobacillus bulgaricus
in Liquid Nitrogen
Authors: Smittle R. B. , Gilliland S. E. , Speck M. L. , Walter W. M.
Published: December 2020

Concentrated cultures of
Lactobacillus bulgaricus
were prepared by resuspending cells grown in semisynthetic media in sterile 10% non-fat milk solids. The concentrated cultures were frozen in liquid nitrogen for 24 h. The cell suspensions exhibited decreased viability after storage, and the amount of death varied among the different strains tested. Storage stability of all strains examined was improved by supplementing the growth medium with sodium oleate. Radioisotopes were used to study the fate of sodium oleate with
L. bulgaricus
NCS1. [1-
14
C]sodium oleate was incorporated solely into the lipid portion of the cells, including both neutral and polar lipids. The fatty acid composition of
L. bulgaricus
NCS1, NCS2, NCS3, and NCS4 grown with and without sodium oleate was studied. The major fatty acids of strains NCS1, NCS2, and NCS3 grown without sodium oleate were dodecanoic, tetradecanoic, hexadecanoic, hexadecenoic, and octadecenoic acids. In addition to these, strain NCS4 contained C
19
cyclopropane fatty acid. The major fatty acids of all strains grown with sodium oleate were tetradecanoic, hexadecanoic, hexadecenoic, octadecenoic, and C
19
cyclopropane fatty acids. All strains grown in broth containing sodium oleate contained larger amounts of octadecenoic and C
19
cyclopropane fatty acid, and less saturated fatty acids than when grown without sodium oleate. Statistical analyses indicated that C
19
cyclopropane fatty acid was most closely related to stability of the lactobacilli in liquid nitrogen. A negative regression line that was significant at
P
< 0.001 was obtained when the cellular content of this fatty acid was plotted against death.
Evaluating the Membrane Fecal Coliform Test by Using
Escherichia coli
as the Indicator Organism
Authors: Hufham James B.
Published: December 2020

The fecal coliform membrane filter method (MFC) currently used in water pollution analysis was evaluated by using two strains of
Escherichia coli
, a known fecal coliform, as the indicator organism. A large relative error in the results obtained with this method was found to be dependent upon the brand of membrane filter employed, the medium, and the temperature of incubation. MFC densities varied between 10 and 60% of the densities determined by means of total bacteria counts and total coliform counts performed at 35 C. Due to the large relative error encountered, the MFC method cannot be recommended as an analytical tool for the laboratory enumeration of
E. coli
. The results do show that the MFC method can be used at 35 C for enumeration of
E. coli
and for differential counts of
E. coli
and
Enterobacter aerogenes
.
Protease Formation by a Moderately Halophilic
Bacillus
Strain
Authors: Kamekura Masahiro , Onishi Hiroshi
Published: December 2020

A moderately halophilic strain of
Bacillus
, isolated from unrefined solar salt, was capable of growth in the presence of 4 M NaCl. Maximal growth was obtained in a medium containing 1 to 2 M NaCl. The organism produced protease when cultivated aerobically in media containing 0 to 3 M NaCl or 0 to 2 M KCl. The protease activity was optimal at 0.5 M NaCl and 0.75 M KCl.
Form of Selenium in Selenite Enrichment Media for Isolation of Salmonellae
Authors: Shrift A. , Boulette R. F.
Published: December 2020

Selenite-F and selenite-cystine media, commercially available for the routine isolation of salmonellae, were treated by anion exchange chromatography to separate the selenium from other components of the media. A chemical assay, based on an ascorbic acid reduction, showed that the selenium was all in the form of selenite.
Microbial Detection Method Based on Sensing Molecular Hydrogen
Authors: Wilkins Judd R. , Stoner Glenn E. , Boykin Elizabeth H.
Published: December 2020

A simple method for detecting bacteria, based on the time of hydrogen evolution, was developed and tested against various members of the
Enterobacteriaceae
group. The test system consisted of (i) two electrodes, platinum and a reference electrode, (ii) a buffer amplifier, and (iii) a strip-chart recorder. Hydrogen evolution was measured by an increase in voltage in the negative (cathodic) direction and recorded on a strip-chart recorder. Hydrogen response curves consisted of (i) a lag period, (ii) a period of rapid buildup in potential due to hydrogen, and (iii) a period of decline in potential. A linear relationship was established between inoculum size and the time hydrogen was detected (lag period). Lag times ranged from 1 h for 10
6
cells/ml to 7 h for 10
0
cells/ml. For each 10-fold decrease in inoculum, length of the lag period increased 60 to 70 min. Mean cell concentrations at the time of hydrogen evolution were 10
6
/ml. Based on the linear relationship between inoculum size and lag period, these results indicate the potential application of the hydrogen-sensing method for rapidly detecting coliforms and other gas-producing microorganisms in a variety of clinical, food, and other samples.
Isolation of Bacteriophages of the Marine Bacterium
Beneckea natriegens
from Coastal Salt Marshes
Authors: Zachary Arthur
Published: December 2020

Bacteriophages of the marine bacterium
Beneckea natriegens
were isolated from coastal marshes where they were limited to brackish and marine waters. The phages were widely distributed and morphologically diverse in the marshes.

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Microbiological Sterol Conversions: Utilization of Selected Mutants
Authors: Cargile Nancy L. , McChesney James D.
Published: December 2020

Microbiological conversion of drugs and natural products, including sterols and steroids, is an important component of the commercial preparation of these agents. We have developed methodology which allows for the production and selection of mutant organisms capable of specific desirable transformations. This methodology is based upon mutation of wild-type strains which are capable of completely degrading certain sterols and selection of the mutants blocked at the desired conversion. This procedure should be equally useful for many if not all drug classes.
Clinical Studies on a Transformation Test for Identification of
Acinetobacter
(Mima and Herellea)
Authors: Brooks Karen , Sodeman Thomas
Published: December 2020

Deoxyribonucleic acid (DNA) from 250 strains of aerobic, nonfermentative, gram-negative coccobacilli and rods were tested for the ability to transform a stable competent auxotroph of
Acinetobacter
(strain
trp E 27
) to prototrophy by using the method established by Juni. Several modifications of Juni's original procedure were made to adapt it for use in a clinical diagnostic laboratory. These modifications were directed primarily towards shortening the procedure to allow completion in a time framework consistent with current procedures. The modifications included changes in sterilization temperature, incubation time and temperature of the competent auxotroph and DNA preparation, overnight incubation temperature, and variations in the age of the auxotroph culture when used. Under these conditions, the transformation can easily be performed in 24 h, the final 16 to 18 h being an overnight uninterrupted incubation period. When used in conjunction with the glucose oxidative fermentative basal metabolism test, it provided a rapid highly efficient means for grouping and identifying acinetobacters which is far superior to a biochemical schema. Without exception, the 141 strains of DNA from
Acinetobacter
species were able to transform the auxotroph to prototrophy. None of the 105 oxidase-positive nonfermenters possessed DNA which was able to transform the
Acinetobacter
auxotroph to prototrophy.
Rumen Bacterial Interrelationships with Plant Tissue During Degradation Revealed by Transmission Electron Microscopy
Authors: Akin Danny E. , Burdick Donald , Michaels Gene E.
Published: December 2020

The mode of rumen bacterial degradation of cell walls in coastal bermudagrass [
Cynodon dactylon
(L) Pers.] differed with the plant tissue type. Bacteria degraded thin, primary cell walls of mesophyll and phloem apparently by extracellular enzymes and without prior attachment; thick-walled bundle sheath and epidermal cells apparently were degraded after bacterial attachment, in some types by an extracellular substance, to the plant cell walls. Rumen bacteria split the nondegraded cuticle from the epidermis by preferentially attacking the cell just underneath the cuticle. The propensity for bacterial attachment to lignified cells of the vascular tissue was low, and bacterial degradation of these cells did not occur after 72 h of incubation.
Immunofluorescent Identification of Mycoplasma Colonies Grown on Agar-Covered Glass Slides
Authors: Lehmkuhl H. D. , Frey M. L.
Published: December 2020

Mycoplasma colonies were grown on microscope slides overlaid with solid medium. After the slides were dried, washed, acetone fixed, and stained with fluorescein-conjugated antisera, specific immunofluorescence was easily observed against a dark background.
Survival of
Saccharomyces cerevisiae
and
Sarcina lutea
at Refrigerator Temperatures
Authors: Tanguay A. E. , Bogert A. B.
Published: December 2020

Assay organisms
Saccharomyces cerevisiae
and
Sarcina lutea
, when suspended in a weak buffer and stored at refrigerator temperatures, are stable for 1 year or more.
Immunofluorescence Approach to the Study of the Ecology of
Thermoplasma acidophilum
In Coal Refuse Material
Authors: Bohlool B. B. , Brock T. D.
Published: December 2020

Specific immunofluorescence staining was applied to the study of the localization, distribution, and growth of
Thermoplasma acidophilum
in its natural habitat, the coal refuse pile. Different antigenic groups of
T. acidophilum
could be isolated from the same refuse pile, and the same antigenic groups were isolated from piles from different geographical areas. No correlation could be established between the antigenic groups and the pH or temperature of the habitats. Brightly fluorescing cells of
T. acidophilum
were detected on microscope slides buried in contact with the coal refuse material or immersed in the water in the stream draining a refuse pile.
T. acidophilum
grew when inoculated into either coal refuse material and/or an aqueous extract of coal refuse when incubated at its optimal temperature of 55 C, but not when incubated at room temperature or 37 C. The coal refuse pile appears to be a primary habitat for
T. acidophilum
.
Physiology of Sporeforming Bacteria Associated with Insects: Minimal Nutritional Requirements for Growth, Sporulation, and Parasporal Crystal Formation of
Bacillus thuringiensis
Authors: Nickerson Kenneth W. , Bulla Lee A.
Published: December 2020

A defined medium is described in which 18 strains of
Bacillus thuringiensis
representing the 12 established serotypes grow, sporulate, and produce a parasporal crystal. This minimal medium contains glucose and salts supplemented with either aspartate, glutamate, or citrate. These organic acids are required and cannot be replaced by vitamin mixtures or succinate even though succinate is taken up at a rate similar to that of aspartate, glutamate, and citrate.
Enhanced Detection of Western Equine Encephalitis Virus Plaque Variants in Crowded Cultures and Plaque Progeny—Potential Use in Genetic Studies
Authors: Stanton G. John , May Deborah Charsha , Jeor S. C. de St.
Published: December 2020

Enhanced detection of large-plaque variants of Western equine encephalitis virus in the presence of large numbers of small-plaque Western encephalitis virus was achieved by using higher bicarbonate concentrations in the agar-overlay medium and increasing concentrations of CO
2
in an enclosed environment during the time plaques were developed with neutral red. By this technique we were able to detect large-plaque mutants in cloned small-plaque suspensions for the first time and to show an increase in detectable plaque progeny in plaques developed by neutral red. Further increase in the number of progeny per plaque was determined by assaying extracts of agar overlaying cultures containing known numbers of plaques. The significance of these findings for potential use in mutational studies is discussed.
Response of
Mycobacterium avium
to Ultraviolet Irradiation
Authors: McCarthy C. M. , Schaefer J. O.
Published: December 2020

The survival response of
Mycobacterium avium
to ultraviolet irradiation demonstrated the presence of a photoreactivating repair system.
Step of Dichlorvos Inhibition in the Pathway of Aflatoxin Biosynthesis
Authors: Yao Raymond C. , Hsieh Dennis P. H.
Published: December 2020

Dichlorvos (dimethyl 2,2-dichlorovinyl phosphate) inhibits the biosynthesis of aflatoxin by
Aspergillus parasiticus
. Cultures treated with dichlorvos excrete an orange pigment which can be converted into aflatoxin B
1
by the untreated mycelia. The orange pigment was partially identified as an acetyl derivative of versiconol-type compound. In the presence of dichlorvos, sterigmatocystin is converted into aflatoxin B
1
without being interfered, but averufin is converted into the orange pigment instead of aflatoxin B
1
. Therefore, dichlorvos appears to block an enzymatic step in the aflatoxin biosynthetic pathway, which lies beyond averufin but before sterigmatocystin, at the formation of the orange pigment.
Computer Program Designed to Follow Fluctuations in Microbial Populations and Its Application in a Study of Chesapeake Bay Microflora
Authors: Oliver James D. , Colwell R. R.
Published: December 2020

A computer program has been developed which performs cluster analysis of microorganisms using methods of numerical taxonomy. The program is designed to group related strains, identify the groups by reference to known strains, and calculate a hypothetical median organism (HMO) for each group. The HMO serves to condense taxonomic information and provides a tag for each strain cluster. Every strain in a group is compared with the HMO established for that group. A representative strain for the group is obtained by selection of the strain showing highest similarity to the HMO. New data sets can be compared with data sets of previous analyses. Hence, the occurrence of the same taxonomic groups within separate data sets can be determined. Quantitative or qualitative differences in distribution of taxonomic groups within or between data sets can be measured. The output from the computer is a graphical display, using an on-line plotter; thus, the investigator is provided with visual comparison of data sets. Results obtained from a study applying the computer program in an analysis of taxonomic data obtained for 43 bacterial strains isolated from Chesapeake Bay indicate the usefulness of this method of taxonomic analysis in microbial ecology.
Modified Radioimmunoassay for Murine Sarcoma-Leukemia Virus Group-Specific Antigen
Authors: Spira Gad , Biswal Nilambar , Dreesman Gordon R.
Published: December 2020

Iodination of disrupted Moloney strain murine sarcoma-leukemia virus resulted in labeled group-specific (gs) protein which was subsequently purified on an isoelectrofocusing column. This iodinated purified gs antigen, prepared from a relatively small quantity of purified virus, was used in a radioimmunoassay. A radioimmunoassay inhibition method was developed so that antibody specific for mammalian C-type gs antigen could be measured in undiluted or low dilutions of test serum without altering the known reagents of the test. The gs antigen isolated from purified Moloney strain murine sarcoma-leukemia virus has an isoelectric point (pH 5.95) which is significantly lower than that reported for other murine leukemia viruses.
Rapid Method for the Radioisotopic Analysis of Gaseous End Products of Anaerobic Metabolism
Authors: Nelson David R. , Zeikus J. G.
Published: December 2020

A gas chromatographic procedure for the simultaneous analysis of
14
C-labeled and unlabeled metabolic gases from microbial methanogenic systems is described. H
2
, CH
4
, and CO
2
were separated within 2.5 min on a Carbosieve B column and were detected by thermal conductivity. Detector effluents were channeled into a gas proportional counter for measurement of radioactivity. This method was more rapid, sensitive, and convenient than gas chromatography-liquid scintillation techniques. The gas chromatography-gas proportional counting procedure was used to characterize the microbial decomposition of organic matter in anaerobic lake sediments and to monitor
14
CH
4
formation from H
2
and
14
CO
2
by
Methanosarcina barkeri
.
Rapid Diagnosis of Infection by Gas-Liquid Chromatography: Analysis of Sugars in Normal and Infected Cerebrospinal Fluid
Authors: Amundson Stanley , Braude Abraham I. , Davis Charles E.
Published: December 2020

A highly reproducible procedure was developed for gas-liquid chromatographic analysis of trimethylsilyl derivatives of normal human cerebrospinal fluid. Fourteen normal human cerebrospinal fluid samples tested with this procedure contained α- and β-glucose as well as isomers of two unidentified sugars. Chromatographic changes in three cases of meningeal inflammation (two cryptococcosis and one thalamic astrocytoma) were limited to decreased concentrations of all sugars. In one case of early meningitis, the concentrations of the unknown sugars decreased before glucose. Now that a reproducible chromatogram of the trimethylsilyl derivatives of normal human cerebrospinal fluid has been established, more samples of abnormal cerebrospinal fluid should be prepared by these methods and examined by gas-liquid chromatography. It may be possible to identify unique products of infectious agents which will permit rapid diagnosis of central nervous system infection.
Detection of
Escherichia coli
Antigens by a Latex Agglutination Test
Authors: Hechemy K. , Stevens R. W. , Gaafar H. A.
Published: December 2020

A latex particle agglutination technique to detect ethylenediaminetetraacetate-solubilized extracts from
Escherichia coli
and whole
E. coli
cells is described. The sensitivity of the serological test was found to be 0.5 to 2.5 ng for the solubilized antigens and 1.5 � 10
6
to 5.7 � 10
6
cells per ml for the particulate antigens. The test was 100 to 1,000 times more sensitive than the standard bacterial agglutination test. Furthermore, it detected
E. coli
antigens during all phases of bacterial growth, whereas the bacterial test detected the antigens only after the mid-log phase. No significant cross-reactivity was observed between latex-anti-
E. coli
preparations and heterologous bacterial strains used in the experimental procedure. A buffer formula containing fatty acid-free bovine albumin prevented nonspecific aggregation of the latex particles.
Color-Coded Antigen for the Automated Reagin Test for Syphilis
Authors: Kasatiya S. S. , Lambert N. G.
Published: December 2020

A low-cost, color-coded antigen was developed for the Automated Reagin Test. A comparative study with 3,000 sera showed a sensitivity somewhat greater than the Rapid Plasma Reagin Card antigen. Samples could be traced back by using a specific color-coded antigen on a given autoanalyzer.
Formations of Extracellular Isoamylase and Intracellular α-Glucosidase and Amylase(s) by
Pseudomonas
SB15 and a Mutant Strain
Authors: Sugimoto Toshiyuki , Amemura Akinori , Harada Tokuya
Published: December 2020

Pseudomonas
SB15, which produces extracellular isoamylase, was found to produce intracellular α-glucosidase and amylase(s) when grown on maltose. A mutant strain (MS1) derived from it, which formed isoamylase constitutively, also produced these intracellular enzymes constitutively. The activities of the enzymes produced in the mutant strain were much greater than those induced in the parent strain.
Statistical Analysis of the Recovery of Coliform Organisms on Gelman and Millipore Membrane Filters
Authors: Schaeffer David J. , Long Maxine C. , Janardan Konanur G.
Published: December 2020

The recovery of coliform organisms on Gelman and Millipore membranes was analyzed by using both a model I (which assumes no error in the
x
variable) and model II (which allows errors in both the variables) regression analysis. The two models afford estimates of the slope which agree within their 95% confidence limits. Using equations derived in this paper, the model II confidence limits on the intercept are obtained. This range does not include the model I intercept limits, thereby demonstrating the differences between results from an incorrect (model I) and correct (model II) approach. In addition, fecal coliform show no differences in response to the two membranes, whereas total coliform exhibit higher recoveries on Gelman membranes.
Serotyping of Adenoviruses Using Immune Electron Microscopy
Authors: Vassall John H. , Ray C. George
Published: December 2020

Immune electron microscopy may be used to determine the type specificity of several common human adenoviruses. The method described utilized equine antisera and was used to serotype adenoviruses within hours after typical cytopathic effect was observed in tissue culture. Adenovirus types 1, 2, 3, 5, 7a, 8, and 11 were isolated from clinical specimens and serotyped by serum neutralization and immune electron microscopy. Five of the seven types were identified consistently and identically by the two methods. Types 7a and 11 were indistinguishable by immune electron microscopy.
Direct Method for Continuous Determination of Iron Oxidation by Autotrophic Bacteria
Authors: Steiner Michael , Lazaroff Norman
Published: December 2020

A method for direct, continuous determination of ferric ions produced in autotrophic iron oxidation, which depends upon the measurement of ferric ion absorbance at 304 nm, is described. The use of initial rates is shown to compensate for such changes in extinction during oxidation, which are due to dependence of the extinction coefficient on the ratio of complexing anions to ferric ions. A graphical method and a computer method are given for determination of absolute ferric ion concentration, at any time interval, in reaction mixtures containing
Thiobacillus ferrooxidans
and ferrous ions at known levels of SO
4
2+
and hydrogen ion concentrations. Some examples are discussed of the applicability of these methods to study of the rates of ferrous ion oxidation related to sulfate concentration.
Technique for Preparing High-Quality Microphotographs by Fluorescence Microscopy
Authors: Elliot J. G. , Carpenter J. A. , Hamdy M. K.
Published: December 2020

Simple techniques resulting in high-quality microphotographs by fluorescence microscopy are described for the preparation of
Salmonella
cultures and slides.
Growth and Reproduction of Microorganisms Under Extremely Alkaline Conditions
Authors: Souza K. A. , Deal P. H. , Mack H. M. , Turnbill C. E.
Published: December 2020

An aerobic and an anaerobic strain of bacteria were isolated from two extremely alkaline springs. Growth and reproduction of both microorganisms were demonstrated above pH 11.0.
Method for In Situ Measurement of Nitrification in a Stream
Authors: Schwert David P. , White James P.
Published: December 2020

A method is described in which the oxidation of NH
3
-N to NO
2
-N and NO
3
-N in a stream was measured in situ by use of an equilibration chamber. The conversion was stoichiometric.
Primary Isolation Of
Mycobacterium chelonei
Subspecies
abscessus
from Pus Inoculated into Peptone Broth
Authors: Crowley Julia , Liu Paul I. , Glassman Armand B.
Published: December 2020

We have described the isolation of
Mycobacterium chelonei
subspecies
abscessus
which on two occasions grew out within 4 days in routine cultures after inoculation with purulent material from injection abscesses in a patient with diabetes mellitus. Media isolation and culture characteristics of this organism in comparison to others in the
Mycobacterium fortuitum
complex are described. Mycobacteria in routine laboratory media can be mistaken for diphtheroids or other “contaminants” or can be overlooked entirely. The possibility of clinical infection of mycobacterial species should be kept in mind when confronted with “sterile” abscesses at injection sites.
Automated Microtransfer Technique for the Assay of Poliovirus- and Mumps Virus-Neutralizing Antibodies
Authors: Mayner Ronald E. , McDorman Donald J. , Meyer Barbara C. , Parkman Paul D.
Published: December 2020

Use of an automated apparatus to quantitate mumps virus- and poliovirus-neutralizing antibody is described. The automated titration equipment affords savings in effort, time, and reagents in conducting large-scale surveys for the determination of mumps- and poliovirus-neutralizing antibodies. This technique has been found to be reproducible and gives results comparable to other antibody assay methods.
Susceptibility of Freshly Picked Ear Corn to Invasion by Fungi
Authors: Stoloff Leonard , Mislivec Philip , Kulik Martin M.
Published: December 2020

High-moisture ear corn held 9 days at 23 C remained free of visible mold or evidence of
Aspergillus flavus
invasion provided there was no mechanical damage of the kernels.
Production and Purification of the Thermophilic Bacteriophage TP-84
Authors: Epstein Israel , Campbell L. Leon
Published: December 2020

A new procedure for production and purification of the thermophilic bacteriophage TP-84 in high yields is described. Cultures of
Bacillus stearothermophilus
strain 10, enriched with nutrients to obtain heavy growth and to prevent sporulation and maintained at a pH of 6.5, were infected with the phage in a 100-liter fermentor. Addition of magnesium chloride (0.01 M) and a temperature of 58 C were essential for maximal phage production. Phage (5 × 10
11
infective particles/ml) was precipitated with polyethylene glycol (molecular weight 6,000) in the presence of sodium chloride and was further purified by cesium chloride density centrifugation.
Metabolism of Glutamic Acid in
Aspergillus ochraceus
During the Biosynthesis of Ochratoxin A
Authors: Bacon C. W. , Robbins J. D. , Burdick D.
Published: December 2020

The uptake and utilization of glutamic acid in the biosynthesis of ochratoxin A by
Aspergillus ochraceus
were studied. Uniformly labeled L-[
14
C]glutamic acid was incorporated into both the phenylalanine and isocoumarin moieties of ochratoxin A. Penicillic acid was also labeled. During the early stages of development, the amino acid was used mainly for the synthesis of ribonucleic acid and protein. A portion of glutamic acid was oxidized and was recovered as metabolic
14
CO
2
. The initial uptake velocity of glutamic acid decreased with age and was pH and temperature dependent. No relationship was found between the initial uptake velocities and ochratoxin A biosynthesis.
Bacterial Flora of the Hemolymph of the Blue Crab,
Callinectes sapidus
: Numerical Taxonomy
Authors: Sizemore R. K. , Colwell R. R. , Tubiash H. S. , Lovelace T. E.
Published: December 2020

Bacteria isolated from the hemolymph of normal blue crabs were found to be predominantly
Vibrio
sp.,
Pseudomonas
sp.,
Acinetobacter
sp.,
Bacillus
sp.,
Flavobacterium
sp., and coliforms.
Vibrio parahaemolyticus
, a cosmopolitan facultative pathogen widely implicated in outbreaks of gastroenteritis related to the consumption of improperly processed seafood, was present in crabs collected between the months of May to November and was identified in up to 21% of the hemolymphs sampled.
Fungal Air Spora at Ibadan, Nigeria
Authors: Ogunlana E. O.
Published: December 2020

The fungal air spora at Ibadan, Nigeria, was investigated by using Casella Slit Samplers. Three sites, incorporating three locations at each site, were selected for the exposure of replicate plates during sampling. To provide data on a wide range of saprophytic and pathogenic fungal spores, isolations were made on Sabouraud dextrose agar and malt agar plates incubated at 26 and 37 C. Altogether over 60,000 fungal colonies were isolated and counted during the 12-month sampling period. The prevalent fungal genera recorded were:
Cladosporum, Curvularia, Fusarium, Aspergillus, Penicillium, Pithomyces, Aureobasidium, Geotrichum, Phoma, Nigrospora, Epicoccum
, and
Neurospora
. The wet and dry seasons (indicated by the temperature, relative humidity, and rainfall data) caused seasonal periodicity in colony numbers. The influence of culture media on the isolated colonies was not significant when the total number of isolated colonies were considered on a monthly basis, but in reviewing a few of the fungal genera there were marked differences between the two media, especially with
Pithomyces
. Attempts were made to identify some of the isolated colonies by species, e.g.,
Aspergillus carneus, Aspergillus flavus, Aspergillus fumigatus, Curvularia geniculata, Fusarium oxysporum, Penicillium herquei, Pithomyces chartaum, Rhizopus arrhizus
, and
Syncephalastrum racemosum
. Such identifications provide a basis for further studies on the role of these fungal species in the frontier problem of contamination and biodegradation of drugs and pharmaceuticals, allergies and other problems in the local environment.
Acetylene Reduction Assays for Nitrogen Fixation Freshwaters: a Note of Caution
Authors: Flett R. J. , Rudd J. W. M. , Hamilton R. D.
Published: December 2020

Lake water samples were observed to transform [
14
C]ethylene into water-soluble compounds that were undetectable by conventional acetylene reduction assay procedures. Methane oxidizing bacteria, which are known to be common in freshwaters, appeared to be responsible for this activity. As much as 28% of added ethylene has been observed to be transformed and this figure is probably an underestimate. It is suggested that acetylene reduction assays may not be accurately applied to samples containing methane oxidizing bacteria.
Growth Curves of Anaerobic Bacteria in Solid Media
Authors: Casciato D. A. , Stewart P. R. , Rosenblatt J. E.
Published: December 2020

Simple pour plate and spectrophotometric techniques for the evaluation of growth curves of several anaerobic bacteria on solid media are described. Three basic patterns of anaerobic growth were observed. The curves obtained were very reproducible when studied on separate occasions. The curves obtained by spectrophotometric measurement were comparable to those obtained by the pour plate method, especially when a large bacterial inoculum was used. Limitations in the interpretation of the results are discussed. The methods and principles reported could provide the basis for the determination of bacterial growth on solid media using other organisms and different experimental conditions.
Microbial Degradation of Polyethylene Glycols
Authors: Haines J. R. , Alexander M.
Published: December 2020

Mono-, di-, tri-, and tetraethylene glycols and polyethylene glycols (PEG) with molecular weight up to 20,000 were degraded by soil microorganisms. A strain of
Pseudomonas aeruginosa
able to use a PEG of average molecular weight 20,000 was isolated from soil. Washed cells oxidized mono and tetraethylene glycols, but O
2
consumption was not detectable when such cells were incubated for short periods with PEG 20,000. However, the bacteria excreted an enzyme which converted low- and high-molecular-weight PEG to a product utilized by washed
P. aeruginosa
cells. Gas chromatography of the supernatant of a culture grown on PEG 20,000 revealed the presence of a compound co-chromatographing with diethylene glycol. A metabolite formed from PEG 20,000 by the extracellular enzyme preparation was identified as ethylene glycol by combined gas chromatography-mass spectrometry.
Radioisotope Assay for the Quantification of Sulfate-Reducing Bacteria in Sediment and Water
Authors: Sand Mark D. , LaRock Paul A. , Hodson Robert E.
Published: December 2020

A radioisotope enrichment culture method was developed to estimate the physiologically active component of a population of sulfate-reducing bacteria in environmental water and sediment samples. Aliquots of water or sediment were added to 50-ml serum bottles filled with
35
S-sulfate broth incubated for approximately 30 h. After incubation, the disintegration rate per milliliter of spent medium was measured, and the percentage of loss of activity resulting from bacterial sulfate reduction was determined. This loss of sulfate from the medium was then translated to a specific number of
Desulfovibrio desulfuricans
cells that would reduce an equivalent amount of sulfate in the same incubation time. This comparison was done using a series of growth curves of
D. desulfuricans
covering a range of inoculum densities between 10
2
and 10
7
cells. The radioassay was used to follow the effects of a pulp mill on a small anoxic river in Florida. The activity of the sulfate-reducing bacteria in the river was greatly suppressed when the mill was closed for annual maintenance. The initiation of waste treatment resulted in improved water quality in 1 week, but the river sediments required a month to show a 10-fold reduction in the population of sulfate-reducing bacteria.
Improved Culture Flask for Obligate Anaerobes
Authors: Daniels Lacy , Zeikus J. G.
Published: December 2020

An improved flask system for the growth of extremely oxygen-sensitive bacteria in liquid culture is described. The improvement described utilizes an all-glass, neoprene-stoppered flask designed for growth of 50- to 1,000-ml cultures of bacteria with continuous gassing.
Semiautomated Microbiological Method for the Assay of Quaternary Ammonium Compounds
Authors: Berg T. M.
Published: December 2020

A semiautomated method has been developed for quantitatively assaying the activity of detergent disinfectants. Automation permitted a high level of reproducibility, which in turn allowed a meaningful comparison between the activities of some types of quaternary ammonium compounds.
Biodegradation of Metal-Nitrilotriacetate Complexes by a
Pseudomonas
Species: Mechanism of Reaction
Authors: Firestone Mary K. , Tiedje James M.
Published: December 2020

A nitrilotriacetate (NTA)-degrading
Pseudomonas
species was shown to degrade Ca, Mn, Mg, Cu, Zn, Cd, Fe, and Na chelates of NTA at nearly equal rates when the appropriate metal concentrations are low enough to avoid toxicity from the freed metal. Ni-NTA, however, was not degraded. When higher concentrations of metal-NTA substrates were used, soil stimulated degradation of Cu, Zn, and Cd complexes, probably as a result of binding toxic freed metals. The metal associated with the NTA substrate does not appear to be transported into the cell, since metals do not accumulate in the cells and the presence of NTA reduces metal toxicity. The data are consistent with the hypothesis that an envelope-associated component, probably a transport protein involved in binding, is responsible for the disassociation of the metal from the NTA. Both soil and this NTA-degrading organism destabilize the metal-NTA complex, which suggests that in the natural environment both would act to limit mobilization of metals as soluble NTA chelates. Crude soluble enzyme preparations degrade Fe-, Mn-, and Na-NTA complexes but not Cu-NTA.
Comparative Inhibitory Effects of Antigen and Antibody in the Staphylococcal Enterotoxin Solid-Phase Radioimmunoassay System
Authors: Bukovic J. A. , Johnson H. M. , Peeler J. T.
Published: December 2020

A solid-phase radioimmunoassay employing
125
I-labeled enterotoxins and polystyrene tubes coated with specific antibody has been developed for assaying the relative concentrations of antibodies to staphylococcal enterotoxins A and B. Competitive binding occurs between tube-bound antibody and free antibody for binding sites on
125
I-labeled enterotoxin. The sensitivity of the system is affected by the amount of antibody on the walls of the tubes, the concentration of
125
I-labeled enterotoxin added to the system, and probably by the relative binding affinities of the bound and unbound antibodies. Antibody, 0.01 to 0.07 μg/ml, inhibited the uptake of
125
I-labeled enterotoxin by 20%. Both the antibody and antigen solid-phase radioimmunoassay inhibition systems can be appropriately represented by either of the following two models: Log
e
(
Y
/1 -
Y
) = α
0
+ α
1
Log
e
X
and Log
e
Y
= β
0
+ β
1
Log
e
X
, where
Y
is bound activity,
X
is antigen or antibody concentration for inhibition, and α
0
, α
1
, β
0
, and β
1
are regression coefficients. Estimates from the first model were slightly more precise for the antibody system, whereas the reverse was true for the antigen system.
Stability of
125
I-Labeled Staphylococcal Enterotoxins in Solid-Phase Radioimmunoassay
Authors: Kauffman Peter E. , Johnson Howard M.
Published: December 2020

Staphylococcal enterotoxins, Types A, B, and C, were labeled with
125
I by the chloramine-T method at approximately two levels of specific activity, 40 and 4 μCi/μg of protein. Toxins labeled with high specific activity showed extensive dissociation of
125
I when stored at different temperatures, including -23 C. In contrast, toxins labeled with low specific activity did not show any significant loss of
125
I when stored at -23 C for as long as 2 months. Enterotoxins, whether labeled with high or low activities, formed aggregates immediately upon labeling. Aggregate formation increased in high-activity-labeled toxins on storage at -23 C, and low-activity-labeled toxins showed no significant increase in aggregate formation, even after 2 months at -23 C. The aggregated forms of the enterotoxins were either devoid of antigenic activity in solid-phase radioimmunoassay or they possessed significantly reduced antigenic activity. Thus, a decrease in binding of
125
I-labeled enterotxin to specific antibody in solid-phase radioimmunoassay results mainly from (i) loss of
125
I on storage, and (ii) formation of aggregates with reduced antigenic activity.
Influence of Colloidal Iron on the Respiration of a Species of the Genus
Acinetobacter
Authors: Rae I. C. Mac , Celo Jovenia S.
Published: December 2020

Washed suspensions of
Acinetobacter
sp. isolated from water caused the precipitation of iron from a suspension of colloidal ferric iron at pH 6.0 and 7.6. Iron-encrusted cells of the bacterium formed large aggregates. The amount of iron removed from the colloidal preparation in the form of aggregates was from 21 to 52% at pH 7.6 and 49% at pH 6.0 by the bacterial cells. Endogenous respiration rates of the iron-encrusted cells were from 32 to 72% lower than the rates for unencrusted cells. Respiration rates, measured polarographically in the presence of glucose, were also greatly reduced by the coating of iron on the cells.
Isolation of
Aeromonas
Sp. ATCC 29063, a Phenol-Producing Organism, from Fresh Haddock
Authors: Chen T. C. , Levin R. E.
Published: December 2020

Attempts to isolate phenol-producing organisms from stale haddock fillets failed. Several such isolates, however, were readily obtained from fresh haddock and were designated
Aeromonas
sp. Phenol was produced from L-tyrosine by these isolates.
Types and Distribution of Obligate Thermophilic Bacteria in Man-Made and Natural Thermal Gradients
Authors: Ramaley Robert F. , Bitzinger Keith
Published: December 2020

The types and distribution of obligate thermophilic bacteria were found to be similar in a thermal gradient resulting from man-made thermal pollution and the thermal gradients of two natural hot springs located in Colorado.
Growth Inhibition of
Rhodopseudomonas capsulata
by Methylmercury Acetate
Authors: Jeffries Thomas W. , Butler Richard G.
Published: December 2020

Growth of
Rhodopseudomonas capsulata
was inhibited in a bacteriostatic manner by as little as 10
-8
M methylmercury acetate (MeHgAc) in unsupplemented synthetic liquid medium or when cells were exposed to 8.0 nm of MeHgAc per mg of cell protein in a single exposure.
Emodin, a Toxic Metabolite of
Aspergillus wentii
Isolated from Weevil-Damaged Chestnuts
Authors: Wells John M. , Cole Richard J. , Kirksey Jerry W.
Published: December 2020

A diarrheagenic toxin from culture extracts of
Aspergillus wentii
Wehmer isolated from weevil-damaged Chinese chestnuts was identified as emodin (2-methyl-4,5,7-trihydroxyanthraquinone). The orange-red, crystalline toxin (mp 255 to 257 C) showed ultraviolet absorption maxima in ethyl alcohol at 223, 250, 267, 290, and 442 nm, and infrared absorption maxima at 3,400 cm
-1
(OH), 1,635, and 1,625 cm
-1
. Chemical shifts and coupling constants of the proton magnetic resonance spectra of the
A. wentii
toxin and of authentic emodin agreed. Mean lethal dose of emodin orally administered to 1 day old DeKalb cockerels was 3.7 mg/kg.
Production of Trichothecene Mycotoxins by
Fusarium
Species in Shake Culture
Authors: Ueno Y. , Sawano M. , Ishii K.
Published: December 2020

Twelve T-2 toxin-producing isolates and four fusarenon-X-producing isolates of
Fusarium
species were examined for their ability to produce trichothecene mycotoxins in shake culture and jar fermentation. T-2 toxin producers such as
Fusarium solani, F. sporotrichioides
, and
F. tricinctum
produced T-2 toxin and neosolaniol in semisynthetic medium.
F. solani
M-1-1 produced the largest amount of the mycotoxins in a nutrient medium consisting of 5% glucose (or sucrose), 0.1% peptone, and 0.1% yeast extract in either shake culture or jar fermentation at 24 to 27 C for 5 days. None of the isolates produced significant amounts of fusarenon-X in shake cultures.