bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigations on the Specificity of the Limulus Test for the Detection of Endotoxin
Authors: Wildfeuer Alexander , Heymer Berno , Schleifer Karl H. , Haferkamp Otto
Published: December 2020

Lysates obtained from amoebocytes of
Limulus polyphemus
, the horseshoe crab, showed gel formation after the addition of bacterial endotoxin. In contrast to living gram-negative bacteria, viable gram-positive microorganisms did not cause gelation of lysate. Nevertheless, peptidoglycan isolated from the cell walls of various gram-positive organisms did induce the reaction. However, the activity of peptidoglycan was 1,000 to 400,000 times less than that of
Escherichia coli
lipopolysaccharide. After exposure to lysozyme, peptidoglycan no longer gelled amoebocyte lysate, therefore apparently excluding endotoxin contamination. Gelation of amoebocyte lysate by endotoxin or peptidoglycan was inhibited by different concentrations of sodium polystyrolsulfonate. Whereas these studies confirm the specificity of the Limulus test for bacterial endotoxins, they also indicate that other substances of bacterial origin should be investigated for their ability to gel amoebocyte lysate.
Rickettsia-Like Organism Causing Disease in a Crangonid Amphipod from Florida
Authors: Federici Brian A. , Hazard Edwin I. , Anthony Darrell W.
Published: December 2020

A rickettsia-like organism causing high mortality and gross pathology has been found infecting over 40% of a population of the freshwater crustacean,
Crangonyx
(near)
floridanus
Bousfield, in Florida. This is the first report of a rickettsia-like organism from a strictly aquatic animal. Morphological and developmental stages of the organisms range in size and shape from small, dense bacilliform cells measuring 150 nm in diameter by 395 nm in length, to large sausage-shaped cells 0.5 by 3 μm.
Formation of Diketopiperazines by
Penicillium italicum
Isolated from Oranges
Authors: Scott Peter M. , Kennedy Barry P. C. , Harwig Joost , Chen Y-K.
Published: December 2020

Prolyl-2-(1′,1′-dimethylallyl)tryptophyldiketopiperazine and 12,13-dehydroprolyl-2-(1′,1′-dimethylallyl)tryptophyldiketopiperazine, known metabolites of
Aspergillus ustus
, were produced in low yield by
Penicillium italicum
in liquid culture and on unsterilized orange peel.
Rapid Detection of Bovine Mycoplasma Antigens by Counterimmunoelectrophoresis
Authors: Cho Hyun J. , Langford Edgar V.
Published: December 2020

Twelve reference strains of mycoplasma and acholeplasma previously reported to have been recovered from cattle were tested against hyperimmune rabbit serum by counterimmunoelectrophoresis. This technique detected antigen by the formation of precipitin lines with antibody within 1 h and promises to be a useful technique for detecting and identifying mycoplasma isolates in either pure or mixed cultures.
Distribution of
Vibrio parahaemolyticus
and Related Organisms in the Atlantic Ocean off South Carolina and Georgia
Authors: Kaneko Tatsuo , Colwell Rita R.
Published: December 2020

The distribution of
Vibrio parahaemolyticus
and related organisms in the Atlantic Ocean was determined during the summer of 1971 from samples collected at stations along four transects on the continental shelf off the South Carolina and Georgia coasts. No
V. parahaemolyticus
strains were isolated from any of the samples of seawater (surface and bottom), sediment, and plankton which were collected. A numerical taxonomy analysis of data on substrate utilization, including 154 organic compounds serving as single carbon sources, was carried out, and four groups of strains were observed. Each group showed well-separated distribution profiles from shore out to the continental shelf. That is, the groupings were observed to correspond to coastal, off-shore and intermediate distribution patterns for the strains. This study provides a useful example of the kind of ecological distributional analysis of bacteria which can be accomplished with numerical taxonomy.
Factors Affecting the Sensitivity of
Limulus
Lysate
Authors: Sullivan James D. , Watson Stanley W.
Published: December 2020

Limulus
lysate clots when mixed with picogram quantities of endotoxins. The sensitivity of the lysate was improved 100-fold by the removal of an inhibitor and addition of divalent cations. The methods developed in this investigation eliminated much of the seasonable variability of the lysate, improved the heat stability after lyophilization, and made it possible to use the lysate with saline solutions.
Further Characterization of Tissue Distribution and Metabolism of [
14
C]Aflatoxin B
1
in Chickens
Authors: Chipley John R. , Mabee Michael S. , Applegate Kenneth L. , Dreyfuss Mark S.
Published: December 2020

The distribution and metabolism of [
14
C]aflatoxin B
1
in chicken tissues were further investigated. Previously dried and frozen ethyl acetate extracts of liver, heart, gizzard, breast, leg, blood, and fecal samples were obtained from either layer or broiler chickens fed subclinical levels of [
14
C]aflatoxin B
1
. Treatment of these extracts with either carboxypeptidase A, leucine aminopeptidase, pepsin, or trypsin revealed that an average of 50% of the
14
C detected in the acetate extracts was a liberated peptide (or amino acid) conjugate of [
14
C]aflatoxin B
2a
. When a prepared standard of B
2a
was made by incubation of B
1
with cold dilute aqueous HCl, the

R
f

values and absorbance maxima were identical with those of the tissue extracts after enzymatic treatment.
Observation of Nitrate Reduction in Some Non-Saccharolytic Strains of
Acinetobacter
Authors: Riley P. S. , Weaver R. E.
Published: December 2020

Clinical isolates of non-saccharolytic
Acinetobacter
species were observed to reduce nitrate.
Latex Test for Quantitative Determination of
Escherichia coli
Antibody
Authors: Hechemy Karim , Stevens Roy , Sroka Jean , Gaafar Hassan
Published: December 2020

A latex agglutination test was developed for assay of anti-
Escherichia coli
antisera. The test is simple, specific, sensitive, and reproducible.
Recovery of
Lactobacillus bulgaricus
and
Streptococcus thermophilus
on Nine Commonly Used Agar Media
Authors: Moon Nancy J. , Hamann A. C. , Reinbold G. W.
Published: December 2020

Of the nine media tested, Eugon, Elliker's lactic agar, pH 6.8, and modified tryptic soy broth agars showed superior recovery of
Lactobacillus bulgaricus
and
Streptococcus thermophilus
strains.
Microbial Degradation of High-Molecular-Weight Alkanes
Authors: Haines J. R. , Alexander M.
Published: December 2020

Measurements of biological O
2
demand showed that normal alkanes containing up to 44 carbon atoms were metabolized by microorganisms.
Effect of Environmental Parameters on Bacterial Degradation of Bunker C Oil, Crude Oils, and Hydrocarbons
Authors: Mulkins-Phillips G. J. , Stewart James E.
Published: December 2020

Mixed microbial cultures, previously enriched on Bunker C fuel oil, grew on and degraded Bunker C fuel oil at temperatures ranging from 5 to 28 C. At 15 C, 41 to 85% of the benzene-soluble components of Bunker C disappeared after incubation for 7 days; at 5 C the values ranged from 21 to 52% after 14 days of incubation. A
Nocardia
sp. isolated from a culture enriched on Bunker C oil grew on Venezuelan crude oil, Bunker C, hexadecane, and a hydrocarbon mixture at temperatures of 5 and 15 C. The 10-C decrease in temperature resulted in an average 2.2-fold decrease in generation time of the bacteria. Gas-liquid chromatographic measurements of Venezuelan and Arabian crude oils which had been incubated with the
Nocardia
sp. showed significant degradation of the
n
-alkane portion and the chromatographically unresolved components of the oils. The concentration of elemental nitrogen required to bring about the disappearance of 1 mg of hexadecane by the
Nocardia
sp. was 0.5 mg. The results confirm suggestions that the rate of natural biodegradation of oil in marine temperate-to-polar zones is probably limited by low temperatures and phosphorus concentrations, but suggest that the concentrations of nitrogen occurring naturally are probably not rate-limiting factors.
Purification of
Clostridium botulinum
Type F Progenitor Toxin
Authors: Ohishi Iwao , Sakaguchi Genji
Published: December 2020

Clostridium botulinum
type F progenitor toxin was purified to a homogeneous state as judged by gel filtration on Sephadex G-200, ultracentrifugation, and disc electrophoresis. The sedimentation constant, corrected to water at 20 C, of type F progenitor toxin was determined to be 10.3 and the molecular weight to be 235,000 by ultracentrifugation at pH 6.0. The purified toxin contained a toxicity of 1.2 × 10
8
50% lethal doses/mg of N. In agar gel double diffusion, it formed two precipitin lines at pH 6.0. The progenitor toxin of type F differs from that of type A in that it contains no hemagglutinin and from that of type E in that it is not activable.
New Method of Grouping Beta-Hemolytic Streptococci Directly on Sheep Blood Agar Plates by Coagglutination of Specifically Sensitized Protein A-Containing Staphylococci
Authors: Edwards E. A. , Larson G. L.
Published: December 2020

A technique is described that allows the grouping of beta-hemolytic streptococci directly upon the primary colony. This was accomplished by applying a small drop of specifically sensitized protein A-containing
Staphylococcus aureus
over a colony of streptococci, rocking the plate to allow mixing of the particles with the soluble group-specific polysaccharide, which in the case of beta-hemolytic streptocicci was produced in abundance during colony formation, and observing for agglutination of the sensitized particles. Such a simple test for group A beta-hemolytic streptococci should allow accurate identification of group A streptococci in small laboratories, such as in clinics or physicians' offices, as well as in the larger public health and private laboratories.
Microbial Transformation of Methyl 5(6)-Butyl-2-Benzimidazolecarbamate
Authors: Valenta J. R. , DiCuollo C. J. , Fare L. R. , Miller J. A. , Pagano J. F.
Published: December 2020

The anthelmintic agent methyl 5(6)-butyl-2-benzimidazolecarbamate (Parbendazole) was transformed to two of its animal metabolites, methyl 5(6)-(4-hydroxybutyl)-2-benzimidazolecarbamate and methyl 5(6)-3-(carboxypropyl)-2-benzimidazolecarbamate, by the filamentous fungus
Cunninghamella bainieri
ATCC 9244. The transformation pathway was shown to be through the 4-hydroxybutyl product to the 3-carboxypropyl product. The reaction favored accumulation of the latter product.
Minimal Growth Requirements for
Clostridium perfringens
and Isolation of Auxotrophic Mutants
Authors: Sebald Madeleine , Costilow Ralph N.
Published: December 2020

The minimal growth requirements for two strains of
Clostridium perfringens
were defined, and both synthetic and semisynthetic plating media were developed. Plate counts of the wild-type strains on both of these minimal media were equivalent to those on complex media. A number of auxotrophic mutants of each strain were isolated, and their phenotypes were defined.
Medium-Scale Production of Citrinin by
Penicillium citrinum
in a Semisynthetic Medium
Authors: Davis N. D. , Dalby D. K. , Diener U. L. , Sansing G. A.
Published: December 2020

A convenient method is described for the production of up to 1.75 g of citrinin per liter by
Penicillium citrinum
growing in stationary culture in a 5-gallon (18.925 liters) carboy containing 4 liters of 4% sucrose and 2% yeast extract medium.
Improved Growth Media for
Vibrio succinogenes
Authors: Kafkewitz David
Published: December 2020

Five new culture media for
Vibrio succinogenes
are described. Of these, a medium composed of 0.4% yeast extract, 100 mM ammonium formate, 120 mM sodium fumarate, and 0.05% sodium thioglycolate, pH 7.3, supports the best growth.
Effect of Polychlorinated Biphenyl Formulations on the Growth of Estuarine Bacteria
Authors: Bourquin Al W. , Cassidy S.
Published: December 2020

Polychlorinated biphenyl formulations inhibited the growth of certain estuarine bacteria. The sensitive strains, although exhibiting some similar physiological characteristics, contained both gram-positive and gram-negative bacteria.

Images
Pathogenic Leptospiras Isolated from Malaysian Surface Waters
Authors: Alexander A. D. , Evans L. B. , Baker M. F. , Baker H. J. , Ellison D. , Marriapan M.
Published: December 2020

Pathogenic leptospiras (1,424) isolated from natural waters and wet soils in Malaysia comprised 29 different serovars (synonym serotypes). All except two of the serovars had been found previously in Malaysia. The exceptional serovars were
werrasingha
, an Autumnalis serogroup member originally isolated in Ceylon, and a new serovar designated
evansi
. Serovar
evansi
had serological affinities with serovar
ranarum
which was isolated from the kidney of a frog in Iowa. The large variety of serovars found in jungle areas was consistent with similar previous findings of diverse serovar infections in troops who had operated in Malaysian jungles.
Incidence of Aflatoxin in California Almonds
Authors: Schade J. E. , McGreevy K. , King A. D. , Mackey B. , Fuller G.
Published: December 2020

In a survey of California almonds, aflatoxin was found in 14% of 74 samples of unsorted, in-shell almonds as received by the processor in 1972, but it occurred at very low levels (below 20 parts per billion [ppb]) in 90% of the contaminated samples. The overall proportion of individual nuts contaminated was especially low and is estimated with 95% probability to have been in the range of 1 nut/55,300 nuts to 1 nut/14,700 nuts. Aflatoxin contamination is not restricted to any particular section of the almond-growing region of California. Commercial sorting procedures are effective in removing most aflatoxin-contaminated nutmeats, since none of 26 samples of processed, whole nutmeats contained aflatoxin. In contrast, 13 of 27 samples of diced almonds were contaminated, but nine of these 13 samples contained less than 20 ppb. Only one of 25 samples of sliced nutmeats contained aflatoxin (4 ppb). Thus, aflatoxin incidence in almonds varies greatly with the category of finished product. The apparent high incidence in diced nutmeats is probably due mostly to the more uniform distribution of aflatoxin occurring in this product (because of its small particle size) than that occurring in the other products. Sample size requirements for monitoring aflatoxin in almonds are discussed.
Degradation of
N
-Nitrosamines by Intestinal Bacteria
Authors: Rowland I. R. , Grasso P.
Published: December 2020

A major proportion of bacterial types, common in the gastrointestinal tract of many animals and man, were active in degrading diphenylnitrosamine and dimethylnitrosamine, the former being degraded more rapidly than the latter. At low nitrosamine concentrations (<0.05 μmol/ml), approximately 55% of added diphenylnitrosamine, 30% of
N
-nitrosopyrrolidine, and 4% of dimethylnitrosamine were degraded. The route of nitrosamine metabolism by bacteria appears to be different from that proposed for breakdown by mammalian enzyme systems in that carbon dioxide and formate were not produced. In bacteria, the nitrosamines were converted to the parent amine and nitrite ion and, in addition, certain unidentified volatile metabolites were produced from dimethylnitrosamine by bacteria. The importance of bacteria in reducing the potential hazard to man of nitrosamines is discussed.
Deoxyribonucleic Acid Base Composition and Biochemical Properties of Certain Coagulase-Negative Enterotoxigenic Cocci
Authors: Lotter Leonard P. , Genigeorgis Constantin A.
Published: December 2020

Eight coagulase-negative, enterotoxigenic strains of cocci and one weakly coagulase-positive strain isolated from a number of different sources, including cases of food poisoning incidents, were evaluated for their relationship to
Staphylococcus aureus
on the basis of deoxyribonucleic acid (DNA) buoyant density and physiological studies. One strain of cocci produced enterotoxins A and C, two strains produced types B and C, four strains produced only type C, and one strain only type D. The enterotoxin produced by one strain of cocci was serologically untypable. None of the test organisms produced detectable amounts of enterotoxin in broth cultures. The test strains of cocci exhibited the following profile: all produced catalase; all grew anaerobically and fermented glucose; five were sensitive to lysostaphin; the percentage of guanine plus cytosine content of their DNA varied from 32.7 to 37.6; five produced acid from mannitol both aerobically and anaerobically; two formed δ-hemolysin; five produced phosphatase and acetoin; and all produced heat-stable nuclease. None of the organisms exhibited typical characteristics of
S. aureus, S. epidermidis
, or
S. saprophyticus
. On the basis of the present data and data reported elsewhere, these organisms should be considered as variants or mutants of
S. aureus
.
Simple Procedure for Production by Group C Streptococci of Phage-Associated Lysin Active Against Group A Streptococci
Authors: Cohen Jay O. , Gross Herman , Harrell William K.
Published: December 2020

Phage-associated lysin of high potency was prepared by growing the host group C streptococcal strain 26RP66 in a semisynthetic medium. The lysin was stabilized by adding dithiothreitol and neutralized ethylenediaminetetraacetic acid (EDTA) to facilitate further concentration and partial purification. The lysin remained active when stored at -65 C for 1 year. Lysin was active against all strains of group A streptococci tested and was more active against living cells than heat-killed cells. The procedure outlined is practicable for most bacteriological research laboratories and does not require column purification or other complex biochemical procedures. It should be useful to any laboratory which requires small amounts of lysin to produce L-forms and protoplasts or to release streptococcal antigens.
Stereoisomeric Specificity and Soil Gas Disequilibria: Implications for Martian Life Detection
Authors: Keeley Lee M. , Meyer Edward D. , Zumberge John E. , Bandurski Eric L. , Nagy Bartholomew
Published: December 2020

Variations in the atmospheric composition of soil samples were monitored by mass spectrometry after the addition of mixtures of D- and L-carbohydrates and/or amino acids. The changes in concentrations of CO
2
in these experiments were found to be related to the stereoisomeric configurations of the compounds with which the soil samples were enriched. The potential of this relationship provides a comparatively simple approach for detecting life in extraterrestrial soils.
Evaluation of Methods for the Isolation of
Salmonella
and
Arizona
Organisms from Pet Turtles Treated with Antimicrobial Agents
Authors: Siebeling R. J. , Neal Philip M. , Granberry W. David
Published: December 2020

Turtles infected with and actively excreting
Salmonella-Arizona
organisms were treated with various concentrations of both Neo-Terramycin (N-Te) and Terramycin (Te) (Pfizer) for various periods of time and then tested for the presence of these pathogens by two methods, excretion and blending. Turtles treated with 200 μg of Te per ml of container water for 9, 12, or 14 days did not excrete detectable numbers of
Salmonella-Arizona
for 6 to 8 weeks, whereas when representative turtles from treatment groups were blended 72 h post-treatment these organisms were isolated from the whole turtle homogenate.
Salmonella
and
Arizona
could be recovered from homogenate prepared from turtles treated for 7 and 14 days with 400, 800, or 1,000 μg of Te or N-Te per ml. These findings suggest that the blending method is more sensitive than the excretion method for the detection of
Salmonella-Arizona
in the treated turtle.
Actinomycetales
from Corn
Authors: Lyons A. J. , Pridham T. G. , Rogers R. F.
Published: December 2020

Mesophilic
Actinomycetales
were isolated from whole corn, brewer's grits, and break flour received from three different mills. In addition, strains were isolated from high-moisture (27%) field corn; high-moisture, silo-stored corn (untreated); and high-moisture corn treated with ammonia, ammonium isobutyrate, or propionic-acetic acid. According to standard techniques, 139 strains were extensively characterized and 207 additional strains were partially characterized. On the basis of these characterizations, the streptomycete strains were identified by both the systems of Pridham et al. and Hütter because these systems are rapid and accurate. In general, only
Streptomyces griseus
(Krainsky) Waksman and Henrici was isolated from high-moisture whole corn (treated or untreated) except from grain exposed to ammonium isobutyrate. Strains isolated from high-moisture corn subjected to that treatment represented both
S. griseus
and
S. albus
(Rossi Doria) Waksman and Henrici. The strains isolated from corn and corn products from the three mills were identified with a number of streptomycete species. Of all
Actinomycetales
isolated, only three were not streptomycetes—two from brewer's grits and one from break flour.
Effects of Mercuric Chloride on Growth and Morphology of Selected Strains of Mercury-Resistant Bacteria
Authors: Vaituzis Z. , Nelson J. D. , Wan L. W. , Colwell R. R.
Published: December 2020

A survey of the comparative cytological effects of growth in the presence of mercury by a group of mercury-resistant bacterial cultures and a characterization of the process of bacterial adaptation to Hg
2+
ion was accomplished. Mercury resistance was found to be dependent upon the ability to volatilize mercury from the medium and upon the amount of mercury accumulated by the cells. The results indicate that most cultures which adapt to growth in the presence of HgCl
2
exhibit extensive morphological abnormalities. Significant effects are delay in the onset of growth and cell division and numerous structural irregularities associated with cell wall and cytoplasmic membrane synthesis and function. A detailed analysis of the adaptation process and the resulting effects on morphology was performed on an
Enterobacter
sp. During the period preceding active multiplication, a selection for mercury-resistant mutants occurred. It was also demonstrated that growth commenced only at a specific threshold concentration of Hg
2+
.
Affinity of Cellular Constituents of Two Bacteria for Fluorescent Brighteners
Authors: Weaver R. W. , Zibilske L.
Published: December 2020

Two fluorescent brighteners were used to stain an isolate of
Bacillus cereus
var.
mycoides
and a soil pseudomonad. The stained organisms were fractionated by two procedures to determine which cellular constituents were reacting with the brighteners. Both fractionation procedures provided evidence that the brighteners were adsorbed to proteins within the cells. Microscopy examination of ghost cells of the bacillus showed that cell walls were not being stained. Spheroplasts of the bacillus and the pseudomonad were stained by the brighteners.
Effect of L-Histidine on the Survival of a T-Strain of Mycoplasma
Authors: Ajello Francesca , Romano Nino
Published: December 2020

The addition of L-histidine to the growth medium prolongs the stationary phase and the survival of a T-strain of mycoplasma. Results of an experiment performed with
14
C-labeled urea demonstrate that the action of L-histidine is based on the retardation of the rise of pH.
Heat-Induced Increase in the Number of Viable Cells in Lyophilized Preparations of
Bacillus popilliae
Authors: Lingg A. J. , McMahon K. J. , Consigli R. A.
Published: December 2020

Viable cells detectable in lyophilized preparations of
Bacillus popilliae
were increased by 72% when dry cells were heated at 60 to 65 C for 2.5 h.
Enhancement of Mycoplasma Virus Plaque Visibility by Tetrazolium
Authors: Fraser Dean , Crum John
Published: December 2020

The plating of mycoplasma virus MVL-1 is greatly improved by the use of tetrazolium to enhance the visibility of the lawn.
Use of pH Gradient Plates for Increasing the Acid Tolerance of Salmonellae
Authors: Huhtanen C. N.
Published: December 2020

Several strains of salmonellae survived higher concentrations of lactic acid after streaking on the surface of pH gradient plates. Most strains increased their acid tolerance by about 0.8 to 1.0 pH unit (9- to 10-fold), with
Salmonella madelia
showing the greatest differential, pH 5.2 in the wild strain and pH 4.2 after conditioning. The increased acid resistance was quickly lost after transferring to normal tryptic soy agar. Tests for survival in a liquid medium at pH values lower than those giving visible growth indicated that these pH values were bactericidal rather than bacteriostatic for both the wild and acid-conditioned strains.
Effect of Exposure to Hyperoxic, Hypobaric, and Hyperbaric Environments on Concentrations of Selected Aerobic and Anaerobic Fecal Flora of Mice
Authors: Gillmore James D. , Gordon Francis B.
Published: December 2020

Alterations in selected aerobic and anaerobic fecal microflora of the mouse were determined during exposure to hyperoxic and normoxic hypo- and hyperbaric environments. Examination of fecal cultures obtained during exposure for 6 weeks to either 60 or 77% oxygen concentration at 1 atmosphere absolute revealed little alteration in the aerobic or anaerobic flora. There appeared to be only a retardation in the reduction of the
Klebsiella-Enterobacter
flora which normally occurs after weaning. During exposure to hypobaric environments (100% O
2
, 0.2 atmosphere absolute), significant alterations in concentrations of
Escherichia coli
, slow lactose fermenters,
Klebsiella-Enterobacter
, and enterococci were found in some instances. All alterations were toward increased concentrations. Variations in concentrations of different colony types of obligately anaerobic gram-positive (anGPR) and gram-negative (anGNR) rods cultured during the same experiments also occurred. One colony type of anGPR appeared to decrease while a second type increased in numbers. Concentrations of three colony types of anGNR were generally, but not always, increased. During hyperbaric exposure (2.8% O
2
, 7.5 atmospheres absolute), increased concentrations of
Klebsiella-Enterobacter, E. coli
, slow lactose fermenters and enterococci were also noted. Changes in numbers of both colony types of anGPR, when occurring, were in the direction of lower numbers. Alteration in numbers of anGNR were in both directions but were more frequent in the direction of higher numbers. After return to normal air for 4 weeks of either hypo- or hyperbaric exposure, fecal concentrations of all organisms tended to revert toward control values with the exception of the anGPR which remained in lower concentrations after termination of the hyperbaric exposure. These observations indicate that, despite the great variation in the fecal flora among individual mice, it is possible to discover the effects induced by altered gaseous environments.
Quantitative Method for the Gas Chromatographic Analysis of Short-Chain Monocarboxylic and Dicarboxylic Acids in Fermentation Media
Authors: Salanitro J. P. , Muirhead P. A.
Published: December 2020

A method for the preparation and gas chromatographic analysis of the butyl esters of volatile (C
1
-C
7
) and nonvolatile (lactic, succinic, and fumaric) acids in microbial fermentation media is presented. Butyl esters were prepared from the dry salts of the acids. The esters were separated by temperature programming on a column of Chromosorb W coated with Dexsil 300 GC liquid phase and analyzed with a flame ionization detector. Apparent recoveries with butanol-HCl or butanol-H
2
SO
4
as butylating agents were 80 to 90% for most acids. Chromatographic profiles of the butyl esters demonstrated that both volatile and nonvolatile acids can be detected and separated in 24 min on a single column. Standard calibration curves (peak area versus concentration) of the butyl esters were linear in the range of 5 to 40 μmol of acid per ml. The advantages of using an internal standard (heptanoic acid) for quantitating fatty acids in a mixture are given. Chromatograms of butylated fermentation media in which rumen anaerobic bacteria were grown illustrated that this method is useful for determining short-chain volatile and nonvolatile acids of taxonomic significance.
Reassessment of the Coagulase and Thermortable Nuclease Tests as Means of Identifying
Staphylococcus aureus
Authors: Rayman M. K. , Park C. E. , Philpott J. , Todd E. C. D.
Published: December 2020

A total of 91 enterotoxigenic strains of
Staphylococcus aureus
isolated from foods and tested for production of coagulase and thermostable nuclease and the ability to ferment glucose and mannitol showed, with the exception of four strains, a complete correlation among these properties. A similar correlation was observed with 103 cultures of
S. aureus
isolated from clinical material. In all instances, the coagulase reactions were sufficiently strong to be scored at either the 3+ or 4+ levels. Presumptive staphylococcal cultures isolated during routine examination of foods and yielding 2+ coagulase reactions or lower were invariably negative for themostable nuclease production. It is suggested that the thermostable nuclease test be performed on cultures with doubtful coagulase reactions before classifying them as
S. aureus
.
H
2
Production by
Selenomonas ruminantium
in the Absence and Presence of Methanogenic Bacteria
Authors: Scheifinger C. C. , Linehan B. , Wolin M. J.
Published: December 2020

Selenomonas ruminantium
is a nonsporeforming anaerobe that ferments carbohydrates primarily to lactate, propionate, acetate and CO
2
. H
2
production by this species has not been previously reported. We found, however, that some strains produce trace amounts of H
2
which can be detected by sensitive gas chromatographic procedures. H
2
production is increased markedly, in some cases almost 100-fold, when the selenomonads are co-cultured with methane-producing bacteria. Growth of the methane-producing bacteria depends on H
2
production by the selenomonads and the subsequent use of H
2
for the reduction of CO
2
to CH
4
. Although no free H
2
accumulates in the mixed cultures, the amount of H
2
formed by the selenomonads can be calculated from the amount of methane produced. These studies indicate that the conventional methods for measuring H
2
production by pure cultures do not provide an adequate estimate of an organism's potential for forming H
2
in an anaerobic ecosystem where H
2
is rapidly used, e.g., for formation of CH
4
.
Microbial Fermentation of Rice Straw: Nutritive Composition and In Vitro Digestibility of the Fermentation Products
Authors: Han Youn W.
Published: December 2020

Rice straw was fermented with
Cellulomonas
sp. and
Alcaligenes faecalis
. Microbial cells and undigested residue, as well as chemically treated (NaOH or NH
4
OH) and untreated straws, were analyzed for nutrient composition and in vitro digestibility. In a typical fermentation, 75% of the rice straw substrate was digested, and 18.6% of the total substrate weight that disappeared was recovered as microbial protein. The microbial cell fraction was 37% protein and 5% crude fiber; the residue was 12% protein and 45% crude fiber. The microbial protein amino acid profile was similar to alfalfa, except for less cysteine. The microbial cells had more thiamine and less niacin than
Torula
yeast. In vitro digestibility of the microbial protein was 41.2 to 55%; that of cellulose was 52%.
Mycotoxin-Producing Potential of Mold Flora of Dried Beans
Authors: Mislivec P. B. , Dieter C. T. , Bruce V. R.
Published: December 2020

To evaluate the potential for mycotoxin production by molds in dried beans, the mold flora of 114 samples was determined both before and after surface disinfection of the beans with 5% NaOCl. Surface disinfection substantially reduced mold incidence, indicating that contamination was mainly on the surface. The flora, both before and after disinfection, was dominated by species of the
Aspergillus glaucus
group, the toxicogenic species
A. ochraceus, Penicillium cyclopium
, and
P. viridicatum
, and species of
Alternaria, Cladosporium
, and
Fusarium
. The toxicogenic species
Aspergillus flavis, A. versicolor, Penicillium citrinum, P. expansum, P. islandicum
, and
P. urticae
were encountered less frequently. Of 209 species of
Aspergillus
and
Penicillium
screened for mycotoxin production on sterile rice substrate, 114 produced one or more of the following mycotoxins:
A. flavus
, aflatoxins;
A. ochraceus
, ochratoxins;
A. nidulans, A. unguis
, and
A. versicolor
, sterigmatocystin;
P. cyclopium
, penicillic acid;
P. citrinum
and
P. viridicatum
, citrinin;
P. urticae
, patulin and griseofulvin. Sterigmatocystin production by
A. unguis
is reported for the first time.
New Method for the Isolation and Identification of Methanogenic Bacteria
Authors: Edwards T. , McBride B. C.
Published: December 2020

A new technique is reported for the rapid growth and detection of methanogenic bacteria by using petri plates. The method employs an anaerobic glove box containing an inner chamber with separate gas-flushing facilities. The numbers of methanogenic bacteria recovered from domestic sewage sludge are comparable to those recovered by other methods. The methanogenic organisms isolated from sludge include
Methanosarcina, Methanospirillum, Methanobacterium
strain M. o. H., and
Methanobacterium formicicum
. Identification of colonies containing methanogenic bacteria is facilitated by taking advantage of the unique fluorescence properties of these organisms. Colonies as small as 0.5 mm can be detected by exposing them to long-wave ultraviolet light.
Plasmid Distribution and Evidence for a Proteinase Plasmid in
Streptococcus lactis
C2
Authors: McKay L. L. , Baldwin K. A.
Published: December 2020

Five plasmids, distinguishable by their molecular weights (10
6
, 2 × 10
6
, 5 × 10
6
, 10
7
, 3 × 10
7
, respectively) were isolated from
Streptococcus lactis
C2. A spontaneous proteinase-negative derivative of this strain lacked the 10
7
plasmid.
Repair and Enumeration of Injured Coliforms by a Plating Procedure
Authors: Speck M. L. , Ray B. , Read R. B.
Published: December 2020

Surface plating of coliforms on Trypticase soy agar, followed by 1 to 2 h of incubation at 25 C and subsequent overlay with violet red bile agar, was found to be a useful method for the repair and enumeration of coliforms injured by freezing.
Pfizer Selective Enterococcus Agar Overlay Method for the Enumeration of Fecal Streptococci by Membrane Filtration
Authors: Daoust Richard A. , Litsky Warren
Published: December 2020

The use of Pfizer selective enterococcus (PSE) agar with the membrane filter technique for the enumeration of fecal streptococci is limited due to the inability of the characteristic black precipitate, indicative of esculin hydrolysis, to diffuse from the medium through the membrane. A modification of the membrane filter technique that consisted of placing the membrane on PSE agar and overlaying it with tempered PSE agar was evaluated by comparing recovery, selectivity, and other parameters with M-enterococcus and KF-streptococcus agars, two selective media routinely used with the membrane filter technique for the enumeration of fecal streptococci in water and wastewater. No statistically significant differences could be demonstrated in the recovery capabilities of the three media. Inasmuch as the PSE overlay technique requires only 24 h of incubation as opposed to 48 h for the other two media, this modification may have some merit in water pollution monitoring programs.
Common Mesophilic Anaerobes, Including Clostridium botulinum
and
Clostridium tetani
, in 21 Soil Specimens
Authors: Smith Louis Ds.
Published: December 2020

A relatively rich medium was markedly superior to a dilute medium for the isolation of anaerobic bacteria from soil. The obligate anaerobes isolated from 21 soil samples were all clostridia and the counts ranged from 2.7 × 10
2
to 3.3 × 10
6
per g. The organisms most frequently isolated were
Clostridium subterminale, C. sordellii, C. sporogenes, C. indolis, C. bifermentans, C. mangenoti
, and
C. perfringens
. Seventeen other species were also recognized but almost one-third of the isolates could not be identified with any known species of
Clostridum. C. botulinum
type A was demonstrated in six soil samples, and type B in one. These soils were neutral to alkaline in reaction (average pH 7.9) and low in organic matter content (1.4%). The association of
C. botulinum
types A and B with neutral to alkaline soils was statistically significant (
P
= 0.001) as was their association with soils low in organic matter (
P
= 0.005).
C. botulinum
types E and F were found in one soil sample, pH 4.5, with organic matter 13.7%.
C. tetani
was isolated from two soil samples, both of intermediate pH value and higher than average organic matter content.
Occurrence of
Klebisiella pneumoniae
in Surface Waters
Authors: Knittel M. D.
Published: December 2020

The occurrence of
Klebsiella pneumoniae
in surface waters was not found to be ubiquitous. When it was isolated,
Escherichia coli
could also be found. The fecal coliform to fecal streptococci ratio suggest that its origin could be human animal, or mixed sources.
Inhibition of Microbial Growth by Fatty Amine Catalysts from Polyurethane Foam Test Tube Plugs
Authors: Bach John A. , Wnuk Richard J. , Martin Delano G.
Published: December 2020

When polyurethane foam test tube plugs are autoclaved, they release volatile fatty amines that inhibit the growth of some microorganisms. The chemical structures of these amines were determined by the use of a gas chromatographmass spectrometer. They are catalysts used to produce the foam. The problem of contaminating growth media with toxic substances released from polymeric materials is discussed.
Effects of Lead on the Lipid Compusition of
Micrococcus luteus
Cells
Authors: Peterson Steven L. , Bennett Larry G. , Tornabene Thomas G.
Published: December 2020

Micrococcus luteus
cells cultivated in medium containing lead salts exhibited a sequence of changes in the quantity of total cellular lipids with essentially no changes from normal cellular yields. The lipid composition of cells cultivated one to four times was moderately decreased (phase I) whereas that of cells cultivated five to six times was reduced by as much as 50% (phase II). Cells cultivated more than six times in lead-containing media had progressively greater quantities of lipid (phase III) approaching that found in control cells. These cells with reestablished lipid contents showed no further effects from more prolonged exposure to lead salts. Chromatographic studies of total lipids of cells of each lipid phase revealed relatively complete lipid compositions. These results indicated that lead is apparently affecting a common biochemical parameter in the biosynthesis of lipids of lipid phase II cells. Changes in the relative quantities of individual components were observed in both the nonpolar and polar lipids in each lipid phase. The most notable changes were the decrease in aliphatic hydrocarbons with concomitant increases in the diglycerides and components identified as a complex family of ketones. Microscopy examinations of control and lead-treated cells revealed electron dense inclusion bodies in membrane fragments in only lead-treated cells.
Dioxane Treatment to Improve Microbial Digestibility of Cellulosic Fibers
Authors: Han Y. W. , Pence J. W. , Anderson A. W.
Published: December 2020

The hemicelluloses of grass seed straws can be extracted rather completely by acid detergent, but the treated residue (acid-detergent fiber) is normally not digested by rumen microorganisms. This residue can be made digestible if it is treated with acidic dioxane.
Degradation of Ethylenediaminetetraacetic Acid by Microbial Populations from an Aerated Lagoon
Authors: Belly R. T. , Lauff J. J. , Goodhue C. T.
Published: December 2020

The ferric chelate of ethylenediaminetetraacetic acid (EDTA) was biologically degraded by a mixed population of microorganisms present in an aerated lagoon receiving this chemical in its feed. As determined radiorespirometrically, 28% of the acetate-2-C and 30% of the ethylene position of the ammonium ferric chelate of [
14
C]EDTA was recovered as
14
CO
2
after 5 days. In a separate experiment using gas liquid chromatography and the sodium ferric chelate, as much as 89% disappearance of EDTA (0.1% wt/vol) was observed during a similar time period. Optimum
14
CO
2
evolution was observed at a pH value between 7 and 8 and at room temperature. Degradation of NH
4
Fe-[2-
14
C]EDTA was stimulated by the addition of either unlabeled NaFe-EDTA, nitrilotriacetic acid or ethylenediamine, and inhibited by the addition of a variety of different sugars and amino acids. Consistent with the biological nature of this degradation, little or no
14
CO
2
evolution was observed after heat treatment of the microorganisms at 100 C for 10 min, or after the addition of formalin or antibiotics to the incubation mixtures. Gas-liquid chromatography and mass spectral analyses were performed to demonstrate EDTA disappearance and to identify various possible intermediates of EDTA degradation.
Potential Pathogens in the Environment: Cultural Reactions and Nucleic Acid Studies on
Klebsiella pneumoniae
from Clinical and Environmental Sources
Authors: Seidler Ramon J. , Knittel Martin D. , Brown Carol
Published: December 2020

The phenotypic and nucleic acid properties of
Klebsiella pneumoniae
have been studied on cultures obtained from six different habitats (humans, vegetables, seeds, trees, rivers, and pulp mills). The 19 cultural reactions of 107 isolates varied significantly only in tryptophanase activity and dulcitol fermentation. The percentage of guanine plus cytosine base composition of 41 isolates varied from 53.9 to 59.2%. The range of percentage of guanine plus cytosine base composition for environmental klebsiellas was broader than that for the cultures of human origin. The range of deoxyribonucleic acid relative reassociation (homology) to the human
K. pneumoniae
reference strain extended from 5% to 100% and the chromosome molecular weights ranged from 2,200 × 10
6
to 3,000 × 10
6
. The species of
K. pneumoniae
is thus molecularly more heterogeneous than previously thought and most isolates of human, pulp mill, and river origin are genetically indistinguishable. The presence of
K. pneumoniae
therefore represents a deterioration of the microbiological quality of the environment and should be considered of public health significance. At the present time the health significance of the molecularly more divergent strains, primarily of vegetable and seed origin, their relationship to klebsiellas of human origin, or to other genera of the
Enterobacteriaceae
is unclear.
Incidence of Molds on Pecan Nuts at Different Points During Harvesting
Authors: Beuchat L. R.
Published: December 2020

Pecan nuts were selected at various points during routine harvesting, and nutmeats were analyzed for gross and internal fungal contamination and for the presence of
Aspergillus flavus
and
A. parasiticus
. Fungi were isolated from a large percentage of the nutmeats at all points of examination. No correlations could be made between increased incidence of fungi and particular harvesting procedures.
Laboratory Method for Fermentation of Meat and Poultry Sausages in Fibrous Casings
Authors: Johnson Michael G. , Acton James C.
Published: December 2020

The construction and operation of a relatively inexpensive cabinet for sausage fermentation studies is described. Temperature can be controlled to ±1 C with a relative humidity of approximately 95%.
Isolation and Identification of a Genus,
Chromobacterium
, Not Previously Found on Processed Poultry
Authors: Cox N. A.
Published: December 2020

An organism identified as
Chromobacterium lividum
was isolated from processed poultry in Georgia.
Deterioration of High-Moisture Corn
Authors: McMahon Michael E. , Hartman Paul A. , Saul Robert A. , Tiffany Lois H.
Published: December 2020

Two small, leaky silos were filled with normal high-moisture corn (HMC), and two with HMC severely infested by
Helminthosporium maydis
. Counts of mesophilic bacteria, lactobacilli, coliforms, yeasts, and molds were made on corn samples as received and periodically thereafter during 220 days of storage. Temperature and gas levels also were monitored. Sequential changes in the populations of lactobacilli, yeasts, and molds were determined during spoilage of HMC. These population changes were compared on the basis of the variables encountered in the present study as well as with the results of previous studies conducted on normal HMC stored under adequate conditions. Heavy infestation by
H. maydis
had no appreciable effect on HMC preservation.
Machine for Printing Hydrophobic Grids on Membrane Filters
Authors: Sharpe A. N.
Published: December 2020

An apparatus for printing wax grids on membrane filters is described. The machine produced more and better hydrophobic grid-membrane filters much more rapidly than by hand.
Production of Cellulose Microfibrils by
Rhizobium
Authors: Napoli Carolyn , Dazzo Frank , Hubbell David
Published: December 2020

Electron microscope examination of
Rhizobium
spp. revealed microfibrils produced by flocculating strains but not by nonflocculating strains. The microfibrils from
R. trifolii
(NA30) were isolated and identified as cellulose by enzymatic, X-ray diffraction, and infrared spectral analyses. Both infective and noninfective strains of
R. trifolii
flocculated and produced microfibrils. More infection threads were observed in clover root hairs growing in the presence of flocs in comparison with root hairs where single bacterial cells predominated.
Presence of Two Virus-Like Particles in
Penicillium citrinum
Authors: Volterra L. , Cassone A. , Tonolo A. , Bruzzone M. L.
Published: December 2020

Two icosahedral virus-like particles (28 and 19 nm in diameter, respectively) have been detected in sporogenic and asporogenic segregants of a strain of
Penicillium citrinum
. The distribution of the two particles differed among the two segregants.
Physiology of Sporeforming Bacteria Associated with Insects: Metabolism of
Bacillus popilliae
Grown in Third-Instar
Popillia japonica
Newman Larvae
Authors: Julian Grant St. , Bulla Lee A. , Hanson Richard S.
Published: December 2020

The timing and relative participation of concurrent pathways of carbohydrate metabolism as well as the extent of terminal respiratory activity were determined by radiorespirometry with
14
C substrates and by enzyme assays for vegetative and sporulating cells of the bacterium
Bacillus popilliae
cultured in whole, intact
Popillia japonica
(Japanese beetle) larvae. During vegetative proliferation, the pentose phosphate pathway predominates in the bacterial cells with minor involvement of the Embden-Meyerhof-Parnas pathway. As the cells proceed through sporulation, pentose phosphate and Embden-Meyerhof-Parnas activity remains constant. No tricarboxylic cycle activity is evident during growth and sporulation of
B. popilliae
. The results demonstrate (i) predominantly aerobic metabolism for carbohydrate assimilation within in vivo sporulating cells, (ii) a major contrast to the metabolism of other aerobic sporeforming bacteria that exhibit derepression of tricarboxylic acid cycle enzymatic activity at the onset of sporulation, and (iii) no causal necessity of the cycle to
B. popilliae
sporogeny.