bluuebunny/crossref_metadata_2025 huggingface dataset:
Utilization of a Further Miniaturized Serological Microtechnique
Authors: Fitzgerald Sandra C. , Fuccillo David A. , Moder Flora , Sever John L.
Published: December 2020

A new 0.01-ml serological microtechnique system produced accurate and reproducible complement-fixation and indirect hemagglutination tests. This equipment involves the use of smaller amounts of antigens and sera, and thus increases the value of the method when employed with expensive reagents or limited qualities of sera.
Some Cultural Conditions That Control Biosynthesis of Lipid and Aflatoxin by
Aspergillus parasiticus
Authors: Shih C. N. , Marth E. H.
Published: December 2020

Synthesis of total lipid and aflatoxin by
Aspergillus parasiticus
as affected by various concentrations of glucose and nitrogen in a defined medium and by different incubation temperatures was studied. Maximal yields of lipid and aflatoxin were obtained with 30% glucose, whereas mold growth, expressed as dry weight, was maximal when the medium contained 10% glucose. Maximal mold growth occurred when the medium contained 3% (NH
4
)
2
SO
4
; however, 1% (NH
4
)
2
SO
4
favored maximum accumulation of lipid and aflatoxin. Growth of mold and synthesis of lipid and toxin also varied with the incubation temperature. Maximal mold growth occurred at 35 C, whereas most toxin appeared at 25 C. Maximal production of lipid occurred at 25 and 35 C but production was more rapid at 35 C. Essentially all glucose in the medium (5% initially) was utilized in 3 days at 25 and 35 C but not in 7 days at 15 and 45 C. Patterns for formation of lipid and aflatoxin were similar at 15 and 25 C when a complete growth medium was used and at 28 C when the substrate contained various concentrations of glucose or (NH
4
)
2
SO
4
. They were dissimilar when the mold grew at 35 or 45 C. At these temperatures lipid was produced preferentially and only small amounts of aflatoxin appeared.
Tryptic Soy Bile-Kanamycin Test for the Identification of
Bacteroides fragilis
Authors: Vargo Valerie , Korzeniowski Myroslawa , Spaulding Earle H.
Published: December 2020

A simple and practical test for the identification of
Bacteroides fragilis
is described. It utilizes two well-known properties of this species, i.e., stimulation of growth by bile and resistance to kanamycin. The test media are a tryptic-soy bile agar plate and a supplemented blood agar plate on which a kanamycin 1,000-μg/ml disk is placed. Incubation is for 24 h at 37 C in GasPak. The results of screening 190 strains, mostly clinical isolates, indicate that
B. fragilis
can be easily and reliably distinguished from other
Bacteroides
and from
Fusobacterium
species by its growth on tryptic-soy bile agar and resistance to kanamycin.
Heterotrophic Potential for Amino Acid Uptake in a Naturally Eutrophic Lake
Authors: Burnison B. Kent , Morita Richard Y.
Published: December 2020

The uptake of sixteen
14
C-labeled amino acids by the indigenous heterotrophic microflora of Upper Klamath Lake, Oregon, was measured using the kinetic approach. The year-long study showed a seasonal variation in the maximum uptake velocity,
V
max
, of all the amino acids which was proportional to temperature. The maximum total flux of amino acids by the heterotrophic microflora ranged from 1.2 to 11.9 μmol of C per liter per day (spring to summer). Glutamate, asparagine, aspartate, and serine had the highest
V
max
values and were respired to the greatest extent. The percentages of the gross (net + respired) uptake of the amino acids which were respired to CO
2
ranged from 2% for leucine to 63% for glutamate. Serine, lysine, and glycine were the most abundant amino acids found in Upper Klamath Lake surface water; at intermediate concentrations were alanine, aspartate, and threonine; and the remaining amino acids were always below 7.5 × 10
-8
M (10 μg/liter). The amino acid concentrations determined chemically appear to be the sum of free and adsorbed amino acids, since the values obtained were usually greater than the (
K
t
+
S
n
) values obtained by the heterotrophic uptake experiments.
Evaluation of Membrane Filter Field Monitors for Microbiological Air Sampling
Authors: Fields N. D. , Oxborrow G. S. , Puleo J. R. , Herring C. M.
Published: December 2020

Due to area constraints encountered in assembly and testing areas of spacecraft, the membrane filter field monitor (MF) and the National Aeronautics and Space Administration-accepted Reyniers slit air sampler were compared for recovery of airborne microbial contamination. The intramural air in a microbiological laboratory area and a clean room environment used for the assembly and testing of the Apollo spacecraft was studied. A significantly higher number of microorganisms was recovered by the Reyniers sampler. A high degree of consistency between the two sampling methods was shown by a regression analysis, with a correlation coefficient of 0.93. The MF samplers detected 79% of the concentration measured by the Reyniers slit samplers. The types of microorganisms identified from both sampling methods were similar. Variables in the MF samplers, such as pore size, relative humidity, and flow rates, have been studied, but no effect was noted on recovery. The results show that the MF method could be used to estimate the number and types of microorganisms found in the air.
Enumeration of Fecal
Clostridium perfringens
Spores in Egg Yolk-Free Tryptose-Sulfite-Cycloserine Agar
Authors: Hauschild A. H. W. , Hilsheimer R. , Griffith D. W.
Published: December 2020

The Shahidi-Ferguson perfringens, tryptose-sulfite-cycloserine (TSC), and egg yolk-free TSC agars have been tested for their suitability to enumerate fecal spores of
Clostridium perfringens
. When these spores comprised at least 20% of the total anaerobe spores, equally accurate counts were obtained in the three media. With lower ratios of
C. perfringens
spores, the most accurate counts were obtained in egg yolk-free TSC agar. The median
C. perfringens
spore count of 60 normal fecal specimens was log 3.4/g. A nonmotile, sulfite- and nitrate-reducing
Clostridium
, not identifiable with any known clostridial species, was isolated from 14 out of 60 fecal specimans. It was not differentiated from
C. perfringens
in the nitrite motility test, but could be distinguished by its inability to liquefy gelatin.
Comparison of Media for Detection of Fungi on Spacecraft
Authors: Herring C. M. , Brandsberg J. W. , Oxborrow G. S. , Puleo J. R.
Published: December 2020

Five media, including Trypticase soy agar (TSA; BBL) pour plates, spread plates of TSA, Mycophil agar with chloromycetin, Mycophil agar with chloromycetin and Actidione, and cornmeal agar with chloromycetin were quantitatively and qualitatively compared for the detection of fungi on spacecraft. Cornmeal agar with chloromycetin yielded the highest number of fungal colonies, although not always significantly higher than Mycophil agar with chloromycetin or TSA spread plates. Cornmeal agar with chloromycetin also gave the best qualitative representation of fungi on the spacecraft, recovering 68% of the genera found from all media. This medium yielded 10 times the number of fungal colonies and 3 times the number of genera found on TSA pour plates as currently used for spacecraft assay.
Characterization of a Virulent Bacteriophage for
Bacillus subtilis
(var.
amyloliquefaciens
)
Authors: Erickson Robert J. , Young Frank E.
Published: December 2020

A phage, designated PBA12, has been isolated from the soil and found to be virulent on
Bacillus subtilis
(var.
amyloliquefaciens
). PBA12 has a large cylindrical head that is 100 nm long and 35 nm in diameter and a tail that is 200 nm in length. The phage contains double-stranded DNA and demonstrates chloroform sensitivity. The processes of both adsorption and replication appear to be slow and inefficient.
Methods for Detecting Carbohydrate Fermentation by Gram-Negative Nonsporeforming Anaerobes
Authors: Fay Gunnar D. , Barry Arthur L.
Published: December 2020

Fermentation of carbohydrates by gram-negative anaerobes may be detected rapidly and conveniently in small volumes of thioglycollate broth, incubated in Gas-Pak jars.
Simple Device for Automatically Transferring Broth Cultures
Authors: Wilkins Judd R. , Mills Stacey M.
Published: December 2020

A simple device is described for automatically transferring broth cultures from one tube to another by means of a tilting platform.
Simple, Inexpensive Method for Controlled Freezing of Cell Cultures
Authors: Ryan Mary M. , Smith Kendall O.
Published: December 2020

We have devised a system for controlled cooling of living cells which eliminates the need for complicated, expensive equipment but allows excellent recovery of viable cells after storage in liquid nitrogen.
Evaluation of a Commercial Latex Agglutination Test Kit for Cryptococcal Antigen
Authors: Kaufman Leo , Cowart Glenda , Blumer Sharon , Stine Amy , Wood Ross
Published: December 2020

Two dozen Crypto-LA kits for detecting
Cryptococcus neoformans
capsular polysaccharide antigens were evaluated. Ten kits proved reliable for detecting and titering antigen in clinical materials. Fourteen kits were found to be inadequate.
Immunochemical Studies on Lipopolysaccharide from Agglutinable and Non-Agglutinable Vibrios
Authors: Guhathakurta Bhakti , Dutta G. C.
Published: December 2020

Lipopolysaccharide (LPS) prepared from
Vibrio cholerae
and a non-agglutinable (NAG; not agglutinable with O-group I serum according to Gardner and Venkatraman [13]) vibrio strain, isolated from a patient with cholera-like clinical symptoms, have been compared with respect to their chemical composition and immunological behavior. In addition to a significant difference in the chemical composition between the two lipopolysaccharides, the LPS from
V. cholerae
, unlike that from the NAG vibrio, requires prior treatment with alkali for it to be an effective antigen in the indirect hemagglutination test with sheep cells. It has been suggested that the alkali acts by removing excess
O
-acetyl group from LPS of agglutinable vibrios. LPS from the NAG vibrio consistently showed a lower antibody response in rabbits in terms of agglutinin and vibriocidal titer. Also, the class of agglutinin antibody elicited by LPS of the NAG vibrio was predominantly immunoglobin M, and that from
V. cholerae
was immunoglobulin G under comparable conditions.
Synthesis of Indicator Strains and Density of Ribonucleic Acid-Containing Coliphages in Sewage
Authors: Dhillon Elvera K. S. , Dhillon T. S.
Published: December 2020

Escherichia coli
strains freshly isolated from natural sources are inefficient indicators of coliphages present in sewage. Four
E. coli
strains recently isolated from clinical specimens were mutagenized to obtain
lac
-
mutants. Such mutants were infected with an
F′lac
+
sex factor of
E. coli
K-12. Pairs of isogenic
lac
-
and
lac
-
/F′
lac
+
strains were used as indicators of coliphages present in sewage, and it was found that such strains can be effectively used for a direct and almost selective enumeration of F-specific coliphage contents of sewage samples. Serological tests were applied to a number of F-specific phages isolated. All the isolates that were tested fell into two distinguishable antigenic classes: members of one class being related to ribonucleic acid (RNA) phage MS2 and those of the other being related to another RNA phage, namely, Qβ. MS2-related phages have been found to be more widely distributed than the Qβ related phages. Most habitats sampled were found to yield only one or the other kind of phage. Single-stranded deoxyribonucleic acid-containing F-specific phages were not detectable by the methods employed by us.
Survival of
Vibrio parahaemolyticus
in Cooked Seafood at Refrigeration Temperatures
Authors: Bradshaw Joe G. , Francis David W. , Twedt Robert M.
Published: December 2020

The growth and survival of two strains of
Vibrio parahaemolyticus
isolated during food-borne gastroenteritis outbreaks in Japan and surface inoculated on cooked shrimp, shrimp with sauce, or cooked crab were tested at various refrigeration temperatures during a 48-h holding period. On cooked shrimp and crab, the vibrios grew well at 18.3 C, but their numbers declined gradually at 10 C and below. At 12.8 C, vibrios remained static for the most part. Thus, it appeared that 12.8 C was the borderline temperature for growth of the organism on cooked seafood. When cocktail sauce was added to surface-inoculated shrimp at a ratio of 2:1, the vibrio die-off rate was accelerated. In the shrimp and sauce few cells remained after 48 h, but in the sauce alone die-off was complete at 6 h.
Preparation of Free Heat-Resistant Ascospores from
Byssochlamys
Asci
Authors: Michener H. David , King A. Douglas
Published: December 2020

When
Byssochlamys
is grown for production of ascospores, some of the asci break up into their constituent ascospores, whereas others do not. For heat resistance studies, it is desirable to prepare a uniform suspension of free ascospores. This was accomplished with the aid of a pressure cell, from which a suspension of asci under high pressure was released to atmospheric pressure through a small orifice. Spores so treated had about the same heat resistance as untreated spores.
Comparative Denitrification of Selected Microorganisms in a Culture Medium and in Autoclaved Soil
Authors: Nash Cheryl L. , Bollag Jean-Marc
Published: December 2020

The denitrifying behavior of selected soil bacteria was compared in a culture solution and in soil that was sterilized by autoclaving. The essential characteristics concerning nitrate reduction and the formation of nitrogenous gases did not change significantly for most bacteria in the two environments. Bacteria whose denitrification product was nitrous oxide evolved the same gas both in soil and in a liquid system, whereas other bacteria formed only nitrogen gas. The validity of laboratory observations in relation to field studies in the domain of denitrification is discussed and evaluated.
Comparison of Three Serological Tests in Gonococcal Infection
Authors: Rodas C. U. , Ronald A. R.
Published: December 2020

Three serological tests used in the diagnosis of gonococcal infection were compared with cultural techniques in 857 females attending the Prenatal and Gynaecology Clinics at the Winnipeg General Hospital. The tests evaluated were the microflocculation technique (MFT), the indirect fluorescent-antibody technique (IFAT), and the complement-fixation technique (CFT). One hundred six patients had positive cultures for
Neisseria gonorrhoeae
. In this population, the MFT was reactive in 80 patients (75.4%), the IFAT was reactive in 74 (69.8%), and the CFT was reactive in 33 (31.1%). In the 751 patients with negative cultures, the MFT was positive in 11.4%, the IFAT was positive in 17.4%, and the CFT was positive in 10.5%. Sera from 9 of 10 patients with gonococcal arthritis were positive with the MFT.
Stomach Fermentation in East African Colobus Monkeys in Their Natural State
Authors: Ohwaki Kyoko , Hungate R. E. , Lotter Leonard , Hofmann R. R. , Maloiy Geoffrey
Published: December 2020

The microbial fermentation in the stomachs of two monkeys,
Colobus polykomos
, collected in Kenya, was studied. The gas accumulated within the stomach contained H
2
but no CH
4
. Volatile fatty acid concentrations were high, but accumulated acid prevented determination of the fermentation rate in untreated, incubated stomach contents. Upon addition of bicarbonate, a very rapid rate could be demonstrated. Some D- and L-lactate were in the stomach contents. Starchy seeds or fruits rather than leaves appeared to have been consumed. Microscopically, the most prominent microorganisms seen were large, very refringent cocci, possibly
Sarcina ventriculi
, and various smaller cocci and rods. The 28 cultured strains of bacteria included 14
Staphylococcus
, 2
Streptococcus
, 10
Propionibacterium
, and 2
Peptostreptococcus
. The culture count constituted 10 to 20% of the direct count. No protozoa or cellulolytic bacteria were found.
Specificity and Sensitivity of the Streptozyme Test for the Detection of Streptococcal Antibodies
Authors: Kholy Aziz El , Hafez Khalil , Krause Richard M.
Published: December 2020

A comparison between the results of the streptozyme hemagglutination test and serological titers for anti-streptolysin O (ASO), anti-hyaluronidase (AH), anti-deoxyribonuclease B (ADN-B), and anti-nicotinamide adenine dinucleotidase (ANAD) was made in two groups of human sera. In one group, serological titers for all the four antibodies were lower than the threshold of sensitization reported by the producing firm. In the second group, the titer of at least one of the four antibodies was equal to or higher than the threshold. False-positive and false-negative reactions occur with those sera when one or more antibody titer is at or near the threshold of the test as described by the manufacturer. The test was positive for all sera where either the ASO was greater than 166 or the ANAD was greater than 270, and for 98% of the sera with ADN-B greater than 360. It is, therefore, concluded that the streptozyme test can be used as an adjunct to the clinical diagnosis of streptococcal infections and their nonsuppurative sequelae. It is less useful to assess the levels of antibodies in sera from general population surveys. For such sera, the relative specificity and sensitivity of the test might yield misleading results. Until more experience is gained with the test, caution should be used in its application to infant and older adult age groups, where significant streptococcal antibody titers are frequently near the threshold of the test.
Interactions of Standard Antibody with Australia Antigens in Au Ag-Ab Radioimmunoassay
Authors: Daugharty Harry , Young Ruth G. , Hatch Milford H. , Ziegler Donald W.
Published: December 2020

Human antisera against Australia (Au) antigen have been characterized by liquid-phase radioimmunoassay (RIA) for their precipitation of
125
I-labeled Au antigen. The end-point dilutions of sera (anti-Au) which precipitated 50% of
125
I-Au antigen by RIA correlated well with complement fixation titers but had a much wider range, indicating a greater precision and perhaps a better sensitivity of assay. Anti-Au serum diluted to precipitate 50% of
125
I-labeled Au antigen was used as standard antibody in RIA tests to detect either inhibition or enhancement of the reaction by preincubated mixtures of Au antigen and antibody specimens. Without free Au antigen or antibody in the resultant mixtures there was no inhibition or enhancement; the mixtures presumably contained immunoreactively equivalent proportions of Au antigen and antibody. RIA data for diagnostic specimens indicated an end-point sensitivity which was proportional to the dilution of the standard anti-Au sera used in the test. High concentrations of the standard antibody permitted detectable inhibition of
125
I-Au antigen precipitation at lower antigen specimen concentrations. Similarly, low concentrations of the standard antibody permitted detectable enhancement of
125
I-Au antigen precipitation at lower antibody specimen concentrations. Omitting the standard antibody altogether resulted in a more sensitive RIA for Au antibody in test sera.
Production of a Potent Vaccine from the Attenuated M-44 Strain of
Coxiella burneti
Authors: Robinson David M. , Hasty Sherman E.
Published: December 2020

The attenuated M-44 strain of
Coxiella burneti
was heated to free it of adventitious agents that may have been present. Parallel titrations of the strain before and after heating indicated that the virulence for guinea pigs was markedly decreased. Guinea pigs immunized with the strain derived after heat treatment were protected from the effects of challenge with
C. burneti
in either phase I or II.
New System for Cultivation of
Neisseria gonorrhoeae
Authors: Martin John E. , Armstrong John H. , Smith P. B.
Published: December 2020

A modified Thayer-Martin medium, containing 2.0% agar, 0.25% dextrose, and 5.0 μg of trimethoprim per ml was compared to Thayer-Martin medium for growth of stock cultures of
Neisseria gonorrhoeae
and for isolation of
N. gonorrhoeae
from clinical specimens. Stock cultures and male urethral cultures grew equally well on both media, but the modified Thayer-Martin medium detected 10% more female patients positive for gonococci. A description is given of the use of a citric acid-sodium bicarbonate tablet for generating carbon dioxide in a sealed plastic bag containing a culture plate. Equivalent results were obtained on duplicate plates of 336 cultures and specimens when this procedure was compared with the standard candle jar extinction method of incubation. The tablet and plastic bag system has the advantages of economy, ease of use, and safety.
Detection of Gas Leaks in an Anaerobic Glove Box
Authors: Jones Gilda L. , Dever Stanley M.
Published: December 2020

An inert gas, Freon, can be added to the atmosphere of an anaerobic glove box without deleterious effect to cultures of anaerobic microorganisms. The sensitive probe of a Halogen Leak Detector passing over the outside surface of the box will pinpoint any escaping Freon and therefore locate the leak.
Propagation of
Geotrichum candidum
in Acid Brine
Authors: Hang Y. D. , Splittstoesser D. F. , Landschoot R. L.
Published: December 2020

Geotrichum candidum
completely neutralized the acid brine and reduced its biochemical oxygen demand (BOD) by 88%. Yield of dry mycelium was 62 g per 100 g of BOD utilized.
One-Tube Test for Determining Oxidative or Fermentative Metabolism of Bacteria
Authors: Brown William J.
Published: December 2020

A one-tube test for distinguishing oxidation from fermentation in the metabolism of carbohydrates was examined on 1,200 gram-negative bacilli. There was a 100% correlation between the one-tube method and the standard two-tube procedure.
Comparative Survival of Indicator Bacteria and Enteric Pathogens in Well Water
Authors: McFeters Gordon A. , Bissonnette Gary K. , Jezeski James J. , Thomson Carole A. , Stuart David G.
Published: December 2020

The comparative survival of various fecal indicator bacteria and enteric pathogens was studied in a stable well water supply by using membrane chambers. There was more variation in the 29 coliform cultures and they died more rapidly, as a group, than the 20 enterococcus cultures that were examined. The comparative survival of the organisms tested follows:
Aeromonas
sp. > the shigellae (
Shigella flexneri, S. sonnei
, and
S. dysenteriae
) > fecal streptococci > coliforms = some salmonellae (
Salmonella enteritidis
ser. paratyphi A and D,
S. enteritidis
ser. typhimurium) >
Streptococcus equinus > Vibrio cholerae > Salmonella typhi > Streptococcus bovis > Salmonella enteritidis
ser. paratyphi B.
S. bovis
had a more rapid die-off than did
S. equinus
, but both had significantly shorter half-lives than the other streptococci. The natural populations of indicator bacteria from human and elk fecal material declined similarly to the pure cultures tested, whereas the die-off of fecal streptococci exceeded the coliforms from bovine fecal material.
Inactivation of Dried Bacteria and Bacterial Spores by Means of Gamma Irradiation at High Temperatures
Authors: Emborg Claus
Published: December 2020

Dried preparations with
Streptococcus faecium
, strain A
2
1, and spores of
Bacillus sphaericus
, strain C
I
A, normally used for control of the microbiological efficiency of radiation sterilization plants and preparations with spores of
Bacillus subtilis
, normally used for control of sterilization by dry heat, formalin, and ethylene oxide, as well as similar preparations with
Micrococcus radiodurans
, strain R
1
, and spores of
Bacillus globigii
(
B. subtilis
, var.
niger
) were gamma irradiated with dose rates from 16 to 70 krad/h at temperatures from 60 to 100 C. At 80 C the radiation response of the spore preparations was the same as at room temperature, whereas the radiation resistance of the preparations with the two vegetative strains was reduced. At 100 C the radiation response of preparations with spores of
B. subtilis
was unaffected by the high temperature, whereas at 16 and and 25 krad/h the radiation resistance of the radiation-resistant sporeformer
B. sphaericus
, strain C
I
A, was reduced to the level of radiation resistance of preparations with spores of
B. subtilis
. It is concluded that combinations of heat and gamma irradiation at the temperatures and dose rates tested may have very few practical applications in sterilization of medical equipment.
Salmonellae in the Environment Around a Chicken Processing Plant
Authors: Hoadley A. W. , Kemp W. M. , Firmin A. C. , Smith G. T. , Schelhorn P.
Published: December 2020

Studies have been conducted over a 2-year period to determine the extent to which a poultry processing plant served as a reservoir of salmonellae reaching the external environment, to examine the question of the importance of salmonellae in the environment, and to consider how best to control the spread of the organisms. The studies have been undertaken at a chicken processing plant handling between 75,000 and 80,000 birds per day. Populations of salmonellae and indicator bacteria were estimated in the raw wastes, through the waste treatment plant, and in the receiving stream waters. The results demonstrate that salmonellae are present in poultry processing wastes in a surprisingly constant relation to fecal coliforms (in excess of 1
Salmonella
per 500 fecal coliforms), that serotypes in the environment are constantly changing, and that they may reflect unusual conditions in the processing plant, or a possible source of infection among human and animal residents of the environment. Disinfection of poultry processing wastes is recommended.
Unusual
Yersinia enterocolitica
Isolates Not Associated with Mesenteric Lymphadenitis
Authors: Bottone Edward J. , Chester Brent , Malowany Moises S. , Allerhand Jona
Published: December 2020

Thirteen
Yersinia enterocolitica
were recovered from a variety of clinical sources. Of these, only one was associated with mesenteric lymphadenitis and belonged to serotype 8. The 12 remaining strains were isolated from nonmesenteric sources and belonged to serotype 17. All strains exhibited the main characteristics of
Y. enterocolitica
which differentiated them from other
Enterobacteriaceae
, i.e., motility at 22 C but not at 37 C, positive urease and ornithine decarboxylase activities, and negative phenylalanine deaminase. These 12 strains differed, however, from other
Y. enterocolitica
previously described in the United States in that they fermented rhamnose and raffinose at 22 C, and failed to grow on Salmonella-Shigella and Hektoen-Enteric agars.
Evaluation of Commercial Conjugates for Fluorescent Antibody Detection of Salmonellae
Authors: Thomason Berenice M. , Hebert G. Ann
Published: December 2020

Fluorescent antibody (FA) reagents for
Salmonella
produced by Difco, Sylvana, and Clinical Sciences, Inc., were evaluated for physicochemical and performance characteristics. The Difco panvalent (A through 064) and the Difco polyvalent (A through S) were similar in physicochemical characteristics. They had less than 60% gamma globulin with 3% albumin and had fluorescein to protein (F/P) ratios of less than 10. The Sylvana conjugate had 81% gamma globulin with less than 1% albumin. Its F/P was 33.9. The Clinical Sciences reagent contained 75% unlabeled albumin as packaged in the Fluoro-kit. Analysis of the original conjugate showed 86.5% gamma globulin with only 0.5% albumin. The (F/P) was 32.8. The performance characteristics were determined by using a variety of
Enterobacteriaceae
and food and feed samples. All conjugates stained the homologous
Salmonella
strains. The majority of cross-reactions were limited primarily to the
Arizona, Citrobacter
, and
Escherichia coli
groups. The Difco panvalent was more reactive with heterologous organisms. It stained 89% of the
Arizona
compared with 42% stained by the Difco polyvalent (A through S) and 39% stained by the Sylvana and Clinical Sciences reagents. We found 90% agreement between FA and culture when the Difco polyvalent was used to examine food and feed samples and 94% agreement when the Clinical Sciences Fluoro-kit was used on another group of samples.
Basic Studies for Continuous Production of L-Aspartic Acid by Immobilized
Escherichia coli
Cells
Authors: Tosa Tetsuya , Sato Tadashi , Mori Takao , Chibata Ichiro
Published: December 2020

By using a column packed with immobilized
Escherichia coli
cells entrapped in a polyacrylamide gel lattice, conditions for continuous production of L-aspartic acid from ammonium fumarate were investigated. When a solution of 1 M ammonium fumarate (pH 8.5) containing 1 mM Mg
2+
was passed through the immobilized cell column at a flow rate of space velocity (SV) = 0.8 at 37 C, the highest rate of reaction was attained. From the column effluents, L-aspartic acid was obtained in good yield. The immobilized cell column was very stable.
Acid Protease Production by Fungi Used in Soybean Food Fermentation
Authors: Wang Hwa L. , Vespa Janet B. , Hesseltine C. W.
Published: December 2020

Growth conditions for maximum protease production by
Rhizopus oligosporus, Mucor dispersus
, and
Actinomucor elegans
, used in Oriental food fermentations, were investigated. Enzyme yields by all three fungi were higher in solid substrate fermentations than in submerged culture. The level of moisture in solid substrate must be at about 50 to 60%. Very little growth of these fungi was noted when the moisture of substrate was below 35%, whereas many fungi including most storage fungi generally grow well on solid substrate with that level of moisture. Among the three substrates tested—wheat bran, wheat, and soybeans—wheat bran was the most satisfactory one for enzyme production. The optimal conditions for maximum enzyme production of the three fungi grown on wheat bran were:
R. oligosporus
, 50% moisture at 25 C for 3 to 4 days;
M. dispersus
, 50 to 63% moisture at 25 C for 3 to 4 days;
A. elegans
, 50 to 63% moisture at 20 C for 3 days. Because these fungi are fast growing and require high moisture for growth and for enzyme synthesis, the danger of contamination by toxin-producing fungi would be minimal.
Proteinase Activity in Slow Lactic Acid-Producing Variants of
Streptococcus lactis
Authors: Pearce L. E. , Skipper N. A. , Jarvis B. D. W.
Published: December 2020

Variants of
Streptococcus lactis
that produce lactic acid slowly in milk were isolated by inducing plasmid loss in the wild type at 39 to 40 C. Such strains had lost most of their surface-bound proteinase activity and were designated
prt
-
. The specific proteinase activities of
S. lactis
C10
prt
+
whole cells and solubilized cell walls were 7 and 18 times, respectively, those of the
prt
-
strain, but spheroplast lysates of
prt
+
and
prt
-
strains contained similar proteinase activity.
S. lactis
H1 showed a similar relative distribution of activity between
prt
+
and
prt
-
cellular fractions, although the overall level was lower. The limited growth in milk, characteristic of
prt
-
strains, can be explained in terms of their low surface-bound proteinase activity.
Isolation of Polyribosomes from Yeast During Sporulation and Vegetative Growth
Authors: Mills Dallice
Published: December 2020

Exponentially growing and sporulating cells of
Saccharomyces cerevisiae
have been subjected to a variety of conditions which mechanically disrupt the cell in an effort to establish conditions which permit the recovery of intact polyribosomes. Grinding cells for 10 s with glass beads in a Bronwill cell homogenizer was sufficiently gentle to yield a polyribosome content in exponentially growing cells which was similar to values obtained from yeast spheroplasts. Polyribosome patterns in sporulating yeast were similar to those from exponentially growing cells. This technique is fast, reproducible over a wide range of cell concentrations, and eliminates the need to make spheroplasts to recover intact polyribosomes.
Production and Some Properties of a New Type of Acid Carboxypeptidase of
Penicillium
Molds
Authors: Yokoyama Sadaji , Oobayashi Akira , Tanabe Osamu , Sugawara Shuichi , Araki Emiko , Ichishima Eiji
Published: December 2020

Among some 38 strains of the genus
Penicillium
we investigated seven wild-type strains (
P. daleae
IFO-6087,
P. frequentans
AHU-8328,
P. funiculosum
IAM-7013,
P. janthinellum
IFO-8070, IAM-7026,
P. lividum
IAM-7200, and
P. oxalicum
AHU-8336) that were found to be excellent strains for a new type of acid carboxypeptidase production in a surface koji culture at 25 C. The production of acid carboxypeptidase was determined in various culture conditions in a koji culture. The maximum yields of acid carboxypeptidase were obtained by
P. janthinellum
IFO-8070. Partial purification and isolation of the acid carboxypeptidase from strains of
Penicillium
were performed with gel filtration on Bio-Gel P-100. Characterization studies indicate that the acid carboxypeptidases from
P. daleae
IFO-6087,
P. funiculosum
IAM-7013,
P. janthinellum
IFO-8070, and
P. oxalicum
AHU-8336 have some properties similar to those of the enzyme of
Aspergillus saitoi
with regard to the hydrolysis of several peptides at acidic pH range but have other slightly different properties with regard to stability, pH optima, inhibitors, and molecular weights.
Survival of R
+
Escherichia coli
in sea Water
Authors: Smith Peter R. , Farrell Evelyn , Dunican Kieran
Published: December 2020

The survival of
Escherichia coli
strains in sea water appears not to be affected by the possession of an R
+
factor. Sea water induces no detectable curing of R
+
E. coli
.
A Serum Bottle Modification of the Hungate Technique for Cultivating Obligate Anaerobes
Authors: Miller Terry L. , Wolin M. J.
Published: December 2020

The modification described utilizes a serum bottle closed with a butyl rubber stopper with a crimped metal seal for the growth of obligately anaerobic bacteria.
Campylobacter fetus
Subspecies
jejuni
(
Vibrio fetus
) from Commercially Processed Poultry
Authors: Smith Merton V. , Muldoon Patrick J.
Published: December 2020

Three isolates of the human and animal pathogen
Campylobacter fetus
ss.
jejuni
(
Vibrio fetus
) were obtained from 165 poultry meat samples purchased from local retail stores.
Volatile Flavor Compounds Produced by Molds of
Aspergillus, Penicillium
, and
Fungi imperfecti
Authors: Kaminski E. , Stawicki S. , Wasowicz E.
Published: December 2020

Strains of molds
Aspergillus niger, A. ochraceus, A. oryzae, A. parasiticus, Penicillium chrysogenum, P. citrinum, P. funiculosum, P. raistrickii, P. viridicatum, Alternaria, Cephalosporium
, and
Fusarium
sp. were grown on sterile coarse wheat meal at 26 to 28 C for 120 h. The volatiles from mature cultures were distilled at low temperature under reduced pressure. The distillates from traps -40 and -78 C were extracted with methylene chloride and subsequently concentrated. All the concentrates thus obtained were analyzed by gas-liquid chromatography, mass spectrometry, chemical reactions of functional groups, and olfactory evaluation. Six components detected in the culture distillates were identified positively: 3-methylbutanol, 3-octanone, 3-octanol, 1-octen-3-ol, 1-octanol, and 2-octen-1-ol. They represented 67 to 97% of all the volatiles occurring in the concentrated distillate. The following 14 components were identified tentatively: octane, isobutyl alcohol, butyl alcohol, butyl acetate, amyl acetate, octyl acetate, pyridine, hexanol, nonanone, dimethylpyrazine, tetramethylpyrazine, benzaldehyde, propylbenzene, and phenethyl alcohol. Among the volatiles produced by molds, 1-octen-3-ol yielding a characteristic fungal odor was found predominant.
Immune Response to
Listeria monocytogenes
in Rabbits and Humans
Authors: Larsen Sandra A. , Feeley John C. , Jones Wallis L.
Published: December 2020

Rabbits were immunized with listeria antigens, staphylococcus antigen, or with both, and the course of their immune response was monitored. Antibodies to
Listeria
and
Staphylococcus
were produced in both immunoglobulin M (IgM) and immunoglobulin G (IgG) classes in response to inoculation with the specific antigen. Cross-responses occurred in rabbits injected only with
Listeria
or only with
Staphylococcus
, as well as in rabbits injected with both antigens.
L. monocytogenes
serotype 4d appeared to be immunologically distinct from
L. monocytogenes
serotype 2 and its cross-reaction with
S. aureus
. Human sera from bacteriologically confirmed cases of listeriosis were examined to determine the nature of the immunological response of man to
Listeria
. In the sera studied, IgM was the predominant antibody produced to
Listeria
, whereas cross-reactions with
Staphylococcus
were observed in both the IgM and the IgG antibody classes.
Rapid Detection of
Clostridium botulinum
Toxin by Capillary Tube Diffusion
Authors: Mestrandrea Leonard W.
Published: December 2020

A micro capillary agar-gel diffusion system for the detection of botulinal toxin in foods and cultures was developed and evaluated. Toxins types A, B, and E, produced in culture broth with and without added trypsin, and type E toxin, produced in inoculated canned clams, were tested with this system and with the mouse bioassay procedure. With nontrypsinized toxin, the capillary diffusion system detected as little as 100 minimal lethal doses (MLD) per ml but was effective only at higher levels, 10
6
to 1.5 × 10
7
MLD/ml, when used with trypsinized toxin. The inability to detect lower levels of trypsinized toxin was due to thioglycolate present in the medium used to produce toxin. Evidently, trypsinization of toxin produces polypeptides still held together by disulfide bonds. Cleavage of these bonds by reduction with thioglycolate reduces the sensitivity of the capillary method. Trypsinized toxin produced in broth without thioglycolate was detected as readily as nontrypsinized toxin. Toxin was detected in canned clams containing as low as 100 MLD/ml. No cross-reactions were observed with type E toxin and types A and B antitoxins. Extensive studies using the capillary method for detecting types A and B toxins were not performed; however, a suspected sample of commercially canned mushrooms gave a positive type B reaction but not a type A reaction. This typing was confirmed later by the mouse bioassay. Toxin was present at a level of 100 MLD/ml. The procedure developed may prove useful as a rapid screening method for the detection of botulinal toxin in foods, with final identification made by using the mouse bioassay.
Modification of the Rapid Fermentation Test for
Neisseria gonorrhoeae
Authors: Brown W. Jerry
Published: December 2020

A modification of the rapid sugar fermentation procedure has been developed because of difficulties encountered in reproducing the reported results. Changes in the method have made the test more sensitive and reproducible.
Isolation of
Acholeplasma laidlawii
from Commercial, Serum-Free Tissue Culture Medium and Studies on Its Survival and Detection
Authors: Low Iolanda E.
Published: December 2020

This report documents the first isolation of
Acholeplasma laidlawii
from a commercial lot of serum-free Dulbecco basal medium. Experimental studies demonstrated survival of the organism for at least 1 year depending on the concentration of the contaminating organism as well as pH and temperature of storage of the serum-free medium. A comparison of isolation methods showed that concentration by filtration through 220-nm membrane filters and testing the filters for mycoplasma recovery, especially when using phenol red-diphasic Hayflick medium, was both sensitive and practical for the average laboratory.
Cellulase Production by
Trichoderma viride
on Feedlot Waste
Authors: Griffin H. L. , Sloneker J. H. , Inglett G. E.
Published: December 2020

Feedlot waste contains essentially all the necessary nutrients for batch fermentation with the fungus
Trichoderma viride
. The organism utilizes two-thirds of the carbohydrate in feedlot waste while elaborating cellulase in quantities comparable to commercial preparations. Essentially odor-free, the fermented waste contains all of the original nitrogen but has 24% less organic matter.
Transformation of 1-Menthene by a
Cladosporium
: Accumulation of β-Isopropyl Glutaric Acid in the Growth Medium
Authors: Mukherjee Barid B. , Kraidman Gary , Hill Ira D.
Published: December 2020

An organism isolated from soil samples collected near a terpene plant grew in the presence of 1-menthene, with no other major source of carbon and energy. The organism was tentatively identified as a member of the genus
Cladosporium
. When this organism was grown in the presence of 1-menthene, with no other major source of carbon, substantial quantities of β-isopropyl glutaric acid accumulated in the fermentation medium. β-Isopropyl glutaric acid is probably an end product of the degradation of 1-menthene by the organism.
Combined Effects of Water Activity, Solute, and Temperature on the Growth of
Vibrio parahaemolyticus
Authors: Beuchat L. R.
Published: December 2020

Vibrio parahaemolyticus
was grown at 36 C in tryptic soy broth (pH 7.8) containing added levels of NaCl ranging from 0.5 to 7.9% (wt/wt). The fastest generation time was 16.4 min in tryptic soy broth containing 2.9% NaCl (TSBS) which corresponded to a water activity (a
w
) of 0.992 (±0.005). Tryptic soy broth containing lower or higher levels of NaCl resulted in higher or lower a
w
, respectively, and slower generation times. Growth was measured turbidimetrically at 36 C in TSBS containing added amounts of NaCl, KCl, glucose, sucrose, glycerol, or propylene glycol. The solutes used to reduce a
w
to comparable levels resulted in extended lag times of varied magnitude, dissimilar growth rates, and different cell numbers. Reduction of a
w
with glycerol was less inhibitory to growth than similar a
w
reductions with NaCl and KCl. Sucrose, glucose, and propylene glycol generally had the greatest effect on extending the lag times of
V. parahaemolyticus
when the addition of these solutes was made to establish similar a
w
levels lower than 0.992. Minimal a
w
for growth at 15, 21, 29, and 36 ± 0.2 C for each of four strains of
V. parahaemolyticus
was tested in TSBS containing added solutes. Reduced a
w
was generally most tolerable at 29 C, whereas higher minimal a
w
for growth was required at 15 C. Solutes added to TSBS to achieve reduction in a
w
, minimal a
w
for growth after 20 days, and incubation temperatures were as follows: glycerol, 0.937, 29 C; KCl, 0.945, 29 C; NaCl, 0.948, 29 C; sucrose, 0.957, 29 and 36 C; glucose, 0.983, 21 C; and propylene glycol, 0.986, 29 C. Each of the four strains tested responded similarly to investigative conditions. It appears that minimal a
w
for growth of
V. parahaemolyticus
depends upon the solute used to control a
w
.
Physical State of Phenanthrene for Utilization by Bacteria
Authors: Wodzinski Richard S. , Coyle Janice E.
Published: December 2020

Experiments were done to determine if bacteria able to utilize phenanthrene as a sole source of carbon obtain the hydrocarbon directly from solid phenanthrene particles suspended in the medium or from the phenanthrene dissolved in the medium. Growth experiments were done in gas-tight fermentors completely filled with air-saturated, mineral salts solution with phenanthrene as the substrate. Generation times were determined by rate of oxygen consumption. Generation times were independent of the amount of solid phenanthrene present, and these generation times were the same as the generation time on medium containing only dissolved phenanthrene. It was concluded that bacteria utilize phenanthrene in the dissolved state.
Rapid Method for Detection and Enumeration of Fecal Coliforms in Fresh Chicken
Authors: Francis D. W. , Peeler J. T. , Twedt R. M.
Published: December 2020

A rapid method for enumerating fecal coliforms in foods was developed employing an agar pour-plate medium. After 7 h of incubation at 41.5 ± 0.05 C, this medium effectively allows the growth of fecal coliforms only. This rapid method was compared with the Association of Official Analytical Chemists multiple-tube dilution method for
Escherichia coli
, by using 21 samples of fresh, cut-up chicken and a surface rinsing procedure for sample preparation. Verification of picked colonies was carried out in EC broth using parallel incubation temperatures of 45.5 and 44.5 ± 0.05 C. Verifications for these temperatures averaged 79 and 98%, respectively. All positively verified isolates were
E. coli
types I and II, as were the negatives. Geometric means for the verified 7-h plate count were within 12% of the standard means for both EC broth incubation temperatures.
Apparatus for Conditioning Unlimited Quantities of Finished Waters for Enteric Virus Detection
Authors: Hill William F. , Akin Elmer W. , Benton William H. , Mayhew Charles J. , Jakubowski Walter
Published: December 2020

An apparatus has been developed, constructed, and tested for conditioning unlimited quantities of finished waters for enteric virus detection.
Serotyping of Avian Mycoplasma Species in India
Authors: Asnani P. J. , Agarwal S. C.
Published: December 2020

Two-hundred and two strains of avian mycoplasma species belonging to 10 biotypes were typed serologically by employing disk growth inhibition (DGI) and indirect hemagglutination (IHA) tests. These could be placed into seven serotypes, namely A (80), B (50), C (3), E (34), L (13), P (4), and 1 and R (18). The figures in parentheses show the number of strains within each type. A close relationship was observed between DGI and IHA tests. The IHA test, however, was more sensitive and specific. It was also noticed that biochemically identical biotypes, namely E and G, and B and M were also found identical in serotyping, thus confirming the biochemical identity. In view of these facts, the strains of biotypes M and G were grouped under serotypes B and E, respectively. The antigenic relationships between the serotypes are also discussed.
Comparative Sensitivity of Gel-Diffusion and Tube Agglutination Tests for the Detection of
Brucella canis
Antibodies in Experimentally Infected Dogs
Authors: Myers Donald M. , Varela-Díaz Víctor M. , Coltorti Emilio A.
Published: December 2020

The microslide gel-diffusion and macro-tube agglutination techniques to detect
Brucella canis
antibodies in dogs were compared. Sera from dogs experimentally infected with
B. canis
and a random sample of dog sera with unknown histories of exposure to this organism were examined. The results of the gel-diffusion method employing specific rough
Brucella
saline-extract antigens of
B. canis
and
Brucella ovis
were comparable to those obtained by the tube agglutination test. The easily prepared, stable R antigen in the freeze-dried form offers a convenient, simple, and reliable diagnostic method for the serological detection of canine brucellosis by the gel-diffusion test.
Involvement of Vitamin B
6
in the Dethiomethylation of Methionine by Rumen Microorganisms
Authors: Merricks D. L. , Salsbury R. L.
Published: December 2020

The dethiomethylation of methionine by a dialyzed extract obtained from the protozoa-rich fraction of rumen fluid is stimulated 2.5-fold by pyridoxal phosphate and strongly inhibited by deoxypyridoxine, a pyridoxal phosphate antagonist. These effects are not seen with undialyzed extracts or with whole rumen fluid. It is suggested that the anaerobic dethiomethylation of methionine by rumen microorganisms requires pyridoxal phosphate as a cofactor.