bluuebunny/crossref_metadata_2025 huggingface dataset:
Microbial Degradation of the Sulfonate of Dodecyl Benzene Sulfonate
Authors: Benarde Melvin A. , Koft Bernard W. , Horvath Raymond , Shaulis Louis
Published: December 2020

It has been observed that the sulfonate portion of alkyl benzene sulfonate (ABS) will undergo microbial attack in certain pure and mixed cultures if an energy source, such as glucose, is available. The evidence for this is provided by the stoichiometric relationship between the reduction of ABS concentration and the appearance of inorganic sulfur compounds.
Determination of Steam-Volatile Organic Acids in Fermentation Media by Gas-Liquid Chromatography
Authors: Packett L. V. , McCune R. W.
Published: December 2020

Five gas chromatographic liquid phases (25% Carbowax 20 M plus 4% H
3
PO
4
, 17.5% dioctyl sebacate plus 7.5% sebacic acid, 17.5% dioctyl sebacate plus 7.5% docosanoic acid, 5% Tween 80, and 20% LAC-296 [poly (diethylene glycol adipate)] plus 2% H
3
PO
4
) were studied with respect to their utility in the separation and quantitation of steam-volatile organic acids commonly produced in fermentation. Optimal operating conditions and column stability for routine analysis were established. An Aerograph Hy-Fi gas chromatograph was used for all work, except the studies with Tween 80 in which an Aerograph A-90-C was employed. Chromatographic traces are presented of volatile fatty acid analyses with each of the liquid phases. Complete separation of all isomers of the fatty acids from C
2
to C
5
was accomplished by the Carbowax 20 M plus H
3
PO
4
, dioctyl sebacate plus sebacic acid, and dioctyl sebacate plus docosanoic acid columns. The latter two liquid phases were extremely unstable and proved to be unsatisfactory for analysis of aqueous samples. A column of Carbowax 20 M + H
3
PO
4
separated steam-volatile organic acids completely. The volatile fatty acid isomers were separated by 5% Tween 80 somewhat less completely, and the peak shapes were not as sharp and symmetrical as that desired for good quantitative work. LAC-296 (20%) plus 2% H
3
PO
4
proved to be the most satisfactory of the liquid phases for routine analysis of deproteinated in vitro rumen fermentation media. The column has been used for routine analysis of rumen fermentation fluid and in vitro rumen incubation fluid. All the organic acids from C
2
to C
5
, except isobutyric, could be quantitated with this column. Stability of the column with the aqueous solutions was extremely good. The standard deviation of the analysis of each volatile acid component in a fermentation fluid was less than 0.5 molar per cent. The short-chain organic acids (C
2
to C
5
) were shown to be extremely stable in aqueous solution for as long as 6 months after preparation for gas chromatographic analysis by protein precipitation with metaphosphoric acid-H
2
SO
4
and refrigeration at 4 C in stoppered tubes.
Fungistatic Performance of 10,10′-Oxybisphenoxarsine in Exterior Latex and Asphalt Coatings
Authors: Wolf Paul A. , Riley W. H.
Published: December 2020

10, 10′-Oxybisphenoxarsine has been found to be outstanding in its activity against bacteria and fungi. Parallel tests with known fungistats for comparison (2,3,4,6-tetrachlorophenol and phenylmercuric acetate) have demonstrated its superior activity and persistence in an exterior acrylate paint film and in an asphalt coating. In view of its superior antimicrobial activity and its persistence, it can be used in applications in which there is no danger of its ingestion. Further field trials are in progress to evaluate 10, 10′oxybisphenoxarsine in paint, asphalt, wood, and in marine pilings.
Comparative Evaluation of Five Selective and Differential Media for the Detection and Enumeration of Coagulase-Positive Staphylococci in Foods
Authors: Crisley F. D. , Peeler J. T. , Angelotti R.
Published: December 2020

Five selective media for the detection and enumeration of coagulase-positive staphylococci were evaluated for their efficiency in the recovery of 17 strains of coagulase-positive staphylococci from foods. They were Staphylococcus Medium 110 (SM-110), tellurite-glycine-agar (TGA), egg-tellurite-glycine-pyruvate-agar (ETGPA), tellurite-egg-agar (TEA), and tellurite-polymyxin-egg yolk-agar (TPEY). Statistical analysis by the rank correlation method of the efficiency with which these media recovered staphylococci from pure 24-hr Brain Heart Infusion cultures revealed the following efficiencies in descending order: (i) TPEY, (ii) ETGPA, (iii) TGA, (iv) TEA, (v) SM-110. Growth of 17 strains of coagulase-negative cocci on these media showed the following approximate descending order of inhibition to these organisms: (i) ETGPA, (ii) TEA, (iii) SM-110, (iv) TGA, (v) TPEY. The appearance of colonies of the various coagulase-negative strains on each medium was studied for the degree to which they could be confused with colonies of coagulase-positive strains. Nineteen food contaminants, including
Proteus vulgaris, Bacillus
sp.,
Escherichia coli, Erwinia
sp., fecal streptococci, and others, were also studied for similarities in appearance to staphylococci and for ability to grow on the selective media. The influence of five sterile food homogenates (frozen chicken and tuna pies, custard, smoked ham, and raw whole egg) on recovery of 1,500 enterotoxigenic staphylococci (three strains) per milliliter was determined by statistical analysis. Three main effects (culture, media, and food) and three interactions (media with food, food with cultures, and media with culture) were found to be significant. Recovery on TPEY was influenced less by food than the other selective media and showed optimal recovery ability from sterile custard, eggs, and ham. TGA recovered well from sterile chicken pie and custard, SM-110 from sterile custard, and TEA from sterile ham. None of the media was outstanding in recovering staphylococci from tuna pie. The ability of the five selective media to recover 1,500 enterotoxigenic staphylococci (three strains) per ml from three sterile foods in the presence of 10 strains of contaminating bacteria added at the 0, 10
5
, and 10
6
levels per milliliter was also studied and analyzed statistically. Only three factors were significant under these conditions—cultures, foods, and the interaction of media with the level of added contamination. Efficiency of recovery of TGA, SM-110, and ETGPA was found not to be dependent upon the level of contamination. Recovery on TPEY decreased with increases in the number of contaminants. TEA increased in efficiency at the 10
5
level, but decreased at the 10
6
level. When recovery on Trypticase Soy Agar was considered to be 100%, the average percentage of recovery by each of the selective media under all experimental conditions was determined.
Absorption and Fluorescence of Water-Soluble Pigments Produced by Four Species of
Pseudomonas
Authors: Wasserman Aaron E.
Published: December 2020

Pigments produced by four species of
Pseudomonas
during growth in three media were examined for visible and ultraviolet absorption. Ultraviolet fluorescence excitation and emission spectra were obtained. In all pigments, an absorption maximum occurs at 405 mμ. Ultraviolet excitation of fluorescence occurs primarily at 400 to 410 mμ, with smaller maxima at 460 mμ, or 525 mμ, depending on
p
H, bacterial species, or medium. Emission maxima, after excitation at 410 mμ, occur at 390 mμ, and 455 to 475 mμ. The differences in fluorescence spectra may be used for taxonomic classification of the
Pseudomonas
.
Detection of Staphylococcal Enterotoxin in Food
Authors: Casman Ezra P. , Bennett Reginald W.
Published: December 2020

Methods are described for the extraction and serological detection of trace amounts of enterotoxins A and B in foods incriminated in outbreaks of staphylococcal food poisoning. Evidence is presented for the probable applicability of the methods for the detection of unidentified enterotoxins.
Effects of Minerals on Neomycin Production by
Streptomyces fradiae
Authors: Majumdar M. K. , Majumdar S. K.
Published: December 2020

A study was made on the mineral requirements of
Streptomyces fradiae
strain 3535 for neomycin production. It was observed that optimal levels of the elements Ca, Fe, and Zn per milliliter of a synthetic medium for neomycin production were 10.8, 1.0, and 0.115 μg, respectively. K
2
HPO
4
was required at a concentration of 0.1% for maximal yield of neomycin, whereas NaCl and the metals Mn and Cu were without any effect. High doses of Zn (0.23 μg/ml or above) caused destruction of neomycin after the fifth day of fermentation.
Isolation, Identification, and Metabolic Role of the Sudanophilic Granules of
Zoogloea ramigera
Authors: Crabtree K. , McCoy E. , Boyle W. C. , Rohlich G. A.
Published: December 2020

Organisms isolated from activated sludge and identified as
Zoogloea ramigera
accumulated large amounts of sudanophilic granules as the cultures flocculated. The granules were extracted by chloroform and precipitated with ether from acid-hydrolyzed cells. Identification of the sudanophilic granules as poly-β-hydroxybutyric acid (PHB) was confirmed by physical, chemical, and infrared spectral analyses. The isolated polymer accounted for 12.0 to 50.5% of the dry weight of the cells. The polymer was not synthesized when the culture was grown in a growth-limiting concentration of organic substrate; it did accumulate when the culture was grown in medium enriched with carbon and energy sources. An increase in concentration of intracellular PHB was directly proportional to optical density and uptake of glucose. Aside from intracellular storage of PHB as endogenous metabolite, the accumulation of PHB is noted as a possible mechanism of flocculation.
Evaluation of Live Tularemia Vaccine Prepared in a Chemically Defined Medium
Authors: Chamberlain Robert E.
Published: December 2020

A chemically defined medium was prepared which adequately supported growth of a vaccine strain of
Pasteurella tularensis
. This medium differed from those previously described in: (i) concentration of components, (ii) a requirement for calcium pantothenate to obtain increased growth, and (iii) a low initial
p
H. Varying the concentration of individual components up to 10 times the standard amount did not increase the viable population or affect dissociation. The vaccine strain grown in this chemically defined medium, although lower in viable population, appears to retain its identity and to be equal in potency to that prepared by the conventional method. This preliminary study indicates the potential utility of this medium as a basis for controlled studies of a live bacterial vaccine in terms of growth characteristics, dissociation, virulence, and immunogenicity.
Cooling Device for Use with a Sonic Oscillator
Authors: Rosett Theodore
Published: December 2020

A cooling cell is described that facilitates maintenance of biological materials at low temperatures during prolonged sonic treatment. Using this cell and a Branson S-75 Sonifier, I examined temperatures and the release of protein and enzyme activity from suspensions of
Saccharomyces cerevisiae
. With the Sonifier at full power, it was possible to maintain cell temperature within 9 C of the cooling-bath temperature, and to disrupt 10% (w/v) suspensions of
S. cerevisiae
in 10 min.
Microbial Ecology of Activated Sludge
Authors: Dias F. F. , Bhat J. V.
Published: December 2020

A comparative estimation of the coliform population of raw sewage, activated sludge, and the effluent derived therefrom revealed that raw sewage had a preponderance of
Escherichia coli
(75%), as compared with 25 and 30%, respectively, in sludge and effluent. Nitrogen-free mannitol-sucrose enrichments of activated sludge resulted in the isolation of
Azotobacter agilis, Aerobacter aerogenes, Corynebacterium laevaniformans
, and an
Achromabacter
species. Sludge had a large population of
C. laevaniformans
and
A. aerogenes
but not of
Azotobacter
. The bacterial parasites,
Bdellovibrio
and bacteriophages, were not active during activated-sludge treatment. A 10-fold reduction in phage content occurred after 2 hr of aeration, but the
Bdellovibrio
population was unaffected.
Agar-Gel Precipitin-Inhibition Technique for C-Reactive Protein Determinations
Authors: Ray John G. , Shay Donald E.
Published: December 2020

The agar-gel precipitin-inhibition test (AGPI) for C-reactive protein determinations proved more sensitive than the capillary tube-precipitin procedure. Furthermore, titers of positive CRP sera were obtained by this AGPI technique. This technique was compared with other indices of infectivity, namely, the white blood cell count and the erythrocyte sedimentation rate. The ease and reproducibility of this recommended test procedure were demonstrated by technicians unfamiliar with this procedure.
Sequential Substrate Removal in a Dilute System by Heterogeneous Microbial Populations
Authors: Bhatla M. N. , Gaudy A. F.
Published: December 2020

The sequential metabolism of substrates by heterogeneous bacterial populations has been previously reported from this laboratory in studies with high substrate concentrations. This phenomenon has now been shown to occur at very dilute substrate concentrations, i.e., 5 mg/liter of glucose plus 5 mg/liter of sorbitol, in studies conducted under the conditions of the standard biochemical oxygen demand (BOD) test. Sequential metabolism of these substrates resulted in a diphasic curve of accumulated oxygen uptake wherein the two phases were separated by a discernible plateau. These findings illustrate one possible explanation for the generation of discontinuity in the kinetic course of carbonaceous BOD exertion.
Removal of Plant Nutrients by Means of Aerobic Stabilization of Sludge
Authors: Irgens Roar L. , Halvorson H. Orin
Published: December 2020

In the conventional treatment of sewage, the solids are normally disposed of by anaerobic digestion. This leaves a considerable amount of plant nutrients, such as nitrogen and phosphate, as soluble compounds which will eventually find their way into the plant's final effluent, since the supernatant fluid from the digesters is normally returned to the raw sewage. In a recent investigation, we found that, if the sludges were treated by an aerobic process, a significant portion of the carbonaceous matter was oxidized to carbon dioxide and water, and the rest was assimilated into microbial protoplasm. This process tied up the available nitrogen and phosphorus so that practically none remained dissolved in the suspending liquid. The accumulated solids, consisting mostly of microbial cells, were separated very easily from the liquid, leaving a slightly colored supernatant fluid that was water-clear, free from plant nutrients, and very low in BOD and COD. The overall process was accomplished in a detention time not exceeding 20 days, in contrast to anaerobic digestion which requires from 50 to 70 days.
Survival of
Clostridium botulinum
Spores
Authors: Anellis A. , Grecz Nicholas , Berkowitz D.
Published: December 2020

Radiation survival curves of spores of
Clostridium botulinum
strain 33A exhibited an exponential reduction which accounted for most of the population, followed by a “tail” comprising a very small residual number [7 to 0.7 spore(s) per ml] which resisted death in the range between 3.0 and 9.0 Mrad dose levels. The “tail” was not caused by protective spore substances released into the suspensions during irradiation, by the presence of accumulated radiation “inactivated” spores, or by heat shock of pre-irradiated spores. The theoretical number of spore targets which must be inactivated by irradiation was estimated both by a graphical and by a computation method to be about 80, and the
D
value was calculated to be 0.295 and 0.396 Mrad, respectively, in buffer and in pork pea broth.
Pertussis Vaccine Testing for Freedom-from-Toxicity
Authors: Pittman Margaret , Cox Claire B.
Published: December 2020

The results of 9.5 years of official testing of vaccines containing pertussis vaccine, plain or adsorbed with alum, Al(OH)
3
, or AlPO
4
, are reported. Toxicity was evaluated by weight changes in mice at 3 and 7 days after injection and intercurrent deaths. Toxicity was encountered during the early use of AlPO
4
in pertussis vaccine products, with a special product and quadruple-antigen vaccines. Throughout the study Al(OH)
3
products, few in number, were the least reactive of the adsorbed products. The slopes of regression lines of graded-dose responses reflected variations in reactivity of “nontoxic” vaccines. The U.S.-prescribed test is discussed relative to the (i) reactivity in children, (ii) causes of toxicity, (iii) other assays for pertussis vaccine toxicity, and (iv) the use of a reference vaccine in the toxicity test.
Survival of
Lactobacillus leichmannii
in Relation to Vitamin B
12
Assays
Authors: Valu Joseph A.
Published: December 2020

Since washed cells of
Lactobacillus leichmannii
ATCC 7830 frequently showed erratic results in vitamin B
12
assays, a depletion technique was used to stabilize the inoculum. The method consisted of incubating the twice-washed cells at 37 C for 45 min in distilled water. Survival and growth studies indicated that the stabilizing procedure (i) did not affect cell numbers, (ii) was optimal for depleting possible carry-over of vitamin B
12
or other nutrilites and reserves, and (iii) brought about a phasing of the cells of the inoculum which underwent logarithmic growth immediately on inoculation. This minimal period (45 min) was the same when the cells were incubated in dextrose-water. Survival of the cells in physiological saline was greater than in distilled water, but a longer time was required for stabilizing the inoculum in saline, which precluded its use in routine work. The prepared inoculum showed an improvement over the washed inoculum in that readings between duplicate and triplicate tubes agreed closely and the standard curves were reproducible whether acidimetric or turbidimetric methods were followed. No erratic results were noted in more than 1 year of testing.
Microbiological Activities of Lysostaphin and Penicillins Against Bacteriophage 80/81 Strains of
Staphylococcus aureus
Authors: Zygmunt Walter A. , Harrison Edward F. , Browder Henry P.
Published: December 2020

Using 20 clinical isolates of
S. aureus
(all bacteriophage 80/81 type), we found that lysostaphin inhibits the growth of all cultures at concentrations significantly lower than those observed with any of eight penicillins, a penicillin-like compound (cephalothin), or fusidic acid (a steroid antibiotic). All test cultures were shown to be resistant to penicillin G, ampicillin, and propicillin. Of the remaining penicillins (all penicillinase-insensitive), oxacillin, nafcillin, cloxacillin, and cephalothin were approximately equal in antimicrobial activity. Ancillin was slightly less active, and methicillin was even lower in potency. Cultures varied more widely in susceptibility to fusidic acid. None of the clinical isolates tested was found to be resistant to lysostaphin.
Soluble Antigen Fluorescent-Antibody Technique
Authors: Toussaint Andre J. , Anderson Robert I.
Published: December 2020

An indirect fluorescent-antibody (FA) procedure employing soluble antigen fixed onto an artificial matrix was developed, and a mechanical means for reading of test results was devised. The method employs two small cellulose acetate paper discs for each test. One disc contains soluble antigen diluted in 1% bovine serum albumin (BSA); the other contains only 1% BSA and serves as a control. After testing by the indirect FA procedure, the results of the tests are read on a fluorometer fitted with a paper chromatogram door. The instrument is set at zero with the control disc as a blank, and the specific fluorescence of the antigen disc is determined. Findings obtained with homologous and heterologous antisera indicated that the method yields excellent results. The soluble antigen fluorescent-antibody technique has definite advantages over the conventional indirect FA procedures. (i) The investigator may objectively select the antigen to be employed. (ii) It is possible to obtain objective mechanical reading of test results rather than the highly subjective readings required by conventional methods. (iii) The system compensates for any nonspecific fluorescence contributed either by the serum (e.g., drugs) or by free fluorescein in the conjugated antiserum.
Deoxyribonucleic Acid Base Composition of Some Members of the Subgenera
Betabacterium
and
Streptobacterium
Authors: Cantoni C. , Hill L. R. , Silvestri L. G.
Published: December 2020

The base composition of deoxyribonucleic acid (DNA) prepared from four
Betabacterium
strains and four
Streptobacterium
strains was determined. Per cent GC values (guanine + cytosine/total bases) of the DNA were evaluated from the “melting-temperatures” (Tm) of the nucleic acids. For the
Betabacterium
strains, these values ranged from 44 to 51.5% GC, and those for the
Streptobacterium
strains ranged from 43 to 47.5% GC. The taxonomic division into these two subgenera is not, therefore, supported by these findings.
Invertase Production by
Penicillium chrysogenum
and Other Fungi in Submerged Fermentation
Authors: Poonawalla F. M. , Patel K. L. , Iyengar M. R. S.
Published: December 2020

A study was made of
Penicillium chrysogenum
and some other fungi to determine the relative distribution of intra- and extracellular invertase produced by them in submerged fermentation. The proportion of each type of enzyme varied with the organism and the period of fermentation. More of the enzyme initially bound to the mycelium was released into the medium with the progress of fermentation. Differences were observed in the effects of cultural conditions on enzyme production in
P. chrysogenum
and
Saccharomyces cerevisiae
. Considerably greater quantities of enzyme were produced by
P. chrysogenum
and the yeast in both laboratory and large-scale fermentors when sucrose was added continuously than when the same quantities of the sugar were added initially.
Assay of Variola Virus by the Fluorescent Cell-Counting Technique
Authors: Hahon Nicholas
Published: December 2020

A quantitative assay for infective variola virus particles was developed which is based on the enumeration of cells containing fluorescent viral antigen after infection of McCoy cell monolayers. The direct fluorescent-antibody technique was employed to stain cells. The efficiency of virus adsorption was markedly enhanced by centrifugation of virus inoculum onto McCoy cell monolayers at 500 ×
g
for 15 min. By this procedure, a proportionality was obtained between the number of fluorescent cells and volume of inoculum. Observations on the sequential development of viral antigen within cells and counts of fluorescent cells showed that the optimal time for enumerating fluorescent cells was after an incubation period of 16 to 20 hr. A linear function existed between virus concentration and cell-infecting units. Fluorescent cells were distributed randomly in infected cover slip cell monolayers. The assay was demonstrated to be highly sensitive, precise, and reproducible.
Evaluation of an Automatic Electronic Device for Counting Bacterial Colonies
Authors: Malligo John E.
Published: December 2020

An automatic colony counter was tested extensively with colonies of two bacterial species,
Serratia marcescens
and
Bacillus subtilis
var.
niger
, grown on agar media. A stable relationship was established between machine counts and counts done visually by technicians. The calibration curve and estimates of the efficiency of the machine are presented and discussed. It is estimated that a 40% reduction in colony counting time is feasible through use of the machine.
Effect of Diquat (1,1′-Ethylene-2,2′-Dipyridylium Dibromide) on the Photosynthetic Growth of
Rhodospirillum rubrum
Authors: Kaneshiro Tsuneo , Zweig Gunter
Published: December 2020

Diquat (2 × 10
-4
m
) inhibited both aerobic and anaerobic growth of
Rhodospirillum rubrum
. With photosynthetic cultures, diquat affected the synthesis of bacteriochlorophyll more readily than cell mass (turbidity). Diquat retarded the synthesis of bacteriochlorophyll and some protein more readily than that of other cellular constituents such as ribonucleic acid, deoxyribonucleic acid, and cell mass. With cells deficient in phosphate, diquat inhibited the uptake-conversion of inorganic phosphate completely only when 3-(3,4-dichlorophenyl)-1,1′-dimethyl urea and ascorbate were also present.
Characteristics of a Proteinase of a
Trichosporon
Species Isolated from Dungeness Crab Meat
Authors: Groninger Herman S. , Eklund M. W.
Published: December 2020

The proteinase of a
Trichosporon
species was partially purified by dialysis, ammonium sulfate fractionation, and Sephadex G-100 gel filtration. A 170-fold purification of the enzyme with a 1.4% recovery of the activity was achieved. The proteinase was separated into a major component and possibly two minor components by starch gel electrophoresis. The
p
H optimum of the enzyme was 5.8 to 6.2. It was active against casein, hemoglobin, and crab protein substrates, but inactive against bovine serum albumin, lysozyme, and benzoylarginine ethyl ester. It was slightly activated by 10 m
m
cysteine, 0.1 m
m
ethylenediaminetetraacetic acid, and 0.1 m
m
Co
++
. There was slight inhibition by 10 m
m
Co
++
and 0.1 m
m
phenylmethylsulfonylfluoride, and total inhibition by 1 m
m
p
-chloromercuribenzoate. The proteinase was completely inactivated by heating at 60 C for 10 min.
Enrichment Medium for Selection of
Salmonella
from Fish Homogenate
Authors: Raj H.
Published: December 2020

A new liquid medium, called “dulcitol selenite enrichment,” has been developed for the detection and enumeration of
Salmonella
in foods. The medium is not only highly selective in enriching
Salmonella
and inhibiting completely or appreciably other extraneous organisms commonly found in seafoods, but is also highly sensitive in recovering as low as 2 to 7 cells of
Salmonella
, even in the presence of large numbers (10
4
to 10
6
cells) of mixed flora common to these foods. The addition of seafood material does not seem to interfere with the sensitivity, selectivity, or productivity of the medium. Even physiologically debilitated cells of
Salmonella
were enriched well enough in this medium to be detected easily.
Effect of Sodium Chloride and
p
H on the Outgrowth of Spores of Type E
Clostridium botulinum
at Optimal and Suboptimal Temperatures
Authors: Segner W. P. , Schmidt C. F. , Boltz J. K.
Published: December 2020

The sodium chloride inhibition of spore outgrowth of four strains of type E
Clostridium bolulinum
was determined in a Trypticase-peptone-glucose (TPG) medium. At 16, 21, and 30 C, spores of three strains required 5.0% and one strain 4.5% salt for complete inhibition during 1 year of incubation. At 8 and 10 C, spores of the four strains required 4.5% salt for definite inhibition. Salt concentrations slightly lower than those providing inhibition tended to extend spore outgrowth time at low temperatures. The minimal
p
H permitting outgrowth of type E spore inocula was affected by the concentration of reducing compound present in the system. When either 0.02% sodium thioglycolate or 0.05% L-cysteine hydrochloride was used, outgrowth at 30 and 8 C occurred at much lower
p
H levels than when 0.2% thioglycolate was added. At 30 C, spores of one strain showed outgrowth in TPG medium as low as
p
H 5.21 with an inoculum of 2 million spores per replicate tube. At a 10-fold higher inoculum, the same strain showed outgrowth at
p
H 5.03 in one of five replicate tubes. At 8 C, spore outgrowth of the four strains occurred at
p
H 5.9, but not at
p
H 5.7, in TPG medium containing L-cysteine hydrochloride.
Enzymatic Techniques for the Study of Pathways of Carbohydrate Utilization in the Rumen
Authors: Palmquist D. L. , Baldwin R. L.
Published: December 2020

Enzymatic techniques were used to study the metabolism of carbohydrates by ruminal bacteria. A direct relationship was observed between the proportions of acetate and propionate formed and the specific activities of the enzymes which participate in forming these acids. An inverse relationship between butyrate formation and butyrate-forming enzymes was observed. The relative activities of succinic dehydrogenase to fumaric reductase, nicotinamide adenine dinucleotide-linked glutamic dehydrogenase to nicotinamide adenine dinucleotide phosphate-linked glutamic dehydrogenase, and pyridine nucleotide-nonlinked lactic dehydrogenase to pyridine nucleotide-linked lactic dehydrogenase were affected by the level of concentrates in the diet. Lactyl coenzyme A dehydrase activity was below the limits of the assay technique in many samples from the alfalfa hay diet, and increased to relatively high levels when concentrates were fed. It is suggested that the enzymatic method will prove valuable for studying the contributions of individual microorganisms to the overall ruminal metabolism, and, with certain limitations, useful for estimating the relative contributions of alternate pathways.
Algicidal Effect of Bromine and Chlorine on
Chlorella pyrenoidosa
Authors: Kott Yehuda , Hershkovitz Galila , Shemtob A. , Sless J. B.
Published: December 2020

Chlorella pyrenoidosa
was found to grow rapidly in tap water. Peak growth was reached after 2 to 3 days. Chlorine and bromine, added to such water, were shown to be effective inhibitors of algal growth. Bromine and bromamine were primarily algicidal, whereas chlorine and chloramines were mainly algistatic. It is assumed that the mechanisms of action of these halogens on
Chlorella
are not the same.
Colonial Morphology of
Escherichia coli
on Tergitol-7 Medium
Authors: Scherer Rhodes K.
Published: December 2020

Escherichia coli
cultures grown on Tergitol-7 medium, with 2,3,5-triphenyltetrazolium chloride added, produced three main types of colonies: rough, intermediate, and mucoid. These colonies were yellow to amber in color and produced slight yellow zones in the medium. Rough colonies were flat, dry, and spreading, with a cut-glass appearance. Intermediate-type colonies varied considerably, but could be divided into two general subtypes. Intermediate-rough colonies had the cut-glass appearance characteristic of rough colonies, but were much more compact and raised, with irregular edges. Intermediate-smooth colonies had a slight cut-glass appearance, but were smooth and entire. Mucoid-type colonies also appeared in two subtypes. Mucoid A colonies were mucoid hemispheres. Mucoid B colonies, after incubation at 37 C for 24 hr, appeared as small, intermediate colonies. However, during a 24-hr holding period at room temperature, mucuslike material proliferated around the colonies. A fourth type of colony was red with blue surrounding medium. Only mucoid-type cultures could not be serologically O-grouped.
Simplified, Accurate Method for Antibiotic Assay of Clinical Specimens
Authors: Bennett John V. , Brodie Jean L. , Benner Ernest J. , Kirby William M. M.
Published: December 2020

Large glass plates are used for this modified agar-well diffusion assay method, allowing up to 81 replications on a single plate. With a specially designed agar punch, it is possible to prepare the small agar wells very quickly. The saving in serum resulting from fewer replications of standards with the large plates, and the small volume of the agar wells, makes it economically feasible to use pooled human serum for the standard antibiotic solutions. Methods are described for preparing the standard solutions, and for providing controls for the deterioration of standards and unknowns. Procedures for preparing and maintaining the commonly used assay organisms are presented. Serum specimens are tested directly rather than diluting them to a narrow range of antibiotic concentrations. This is possible because of a procedure for calculations that recognizes the curvilinear relationship between zone sizes and antibiotic concentrations. Adaptation of this method to a number of the commonly used antibiotics is described. With this method, it has been possible to test large numbers of clinical specimens in a minimal time, and with accuracy consistently better than 10%.
Biochemical Differentiation of the
Enterobacteriaceae
with the Aid of Lysine-Iron-Agar
Authors: Johnson Jane G. , Kunz Lawrence J. , Barron Winifred , Ewing W. H.
Published: December 2020

A procedure is described for identifying members of the family
Enterobacteriaceae
isolated from clinical specimens. The methods are based on primary differentiation of the various groups of bacteria by the use of Kligler Iron Agar and lysine-iron-agar. For identification of
Salmonella, Shigella
, and Arizona group organisms from stools, Triple Sugar Iron Agar and lysine-iron-agar are employed. The usefulness of this schema for diagnostic bacteriology laboratories is discussed. It is not intended to replace methods used in reference or research laboratories.
Survival and Recovery of Enterovirus from Foods
Authors: Lynt Richard K.
Published: December 2020

Type 1 poliovirus and type B1 and B6 coxsackieviruses added to eight commercial frozen or convenience foods before storage at room temperature, 10 C, and -20 C were still viable after various intervals of time up to 1 week, 1 month, and 5 months, respectively. Infectivity titers were determined in monkey kidney tissue culture. Decomposition which took place in food stored at room temperature did not affect the survival of virus, and antibiotics controlled bacterial growth during assay. A rapid, significant reduction in type B6 coxsackievirus was observed in cole slaw. Preliminary data indicate that sodium bisulfite could be the responsible ingredient. A less rapid reduction of type 1 poliovirus and type B6 coxsackievirus was found in hashed brown potatoes when stored at 10 C.
Use of the Anaerobic Pouch in Isolating
Clostridium botulinum
Spores from Fresh Meats
Authors: Greenberg Richard A. , Bladel Bendt O. , Zingelmann Walter J.
Published: December 2020

The anaerobic film pouch was demonstrated to be an effective device for the primary isolation of
Clostridium botulinum
types A and B spores from raw pork, beef, and chicken. Optimal pasteurization of these meats (for reduction of nonspore microflora without affecting indigenous putrefactive anaerobic spore levels) was 50 min at 60 C.
C. botulinum
spores were recovered with good precision from meat samples inoculated with mixtures of
C. botulinum
and Putrefactive Anaerobe 3679 at 1:1 and at 1:99 ratios. Verification of
C. botulinum
isolates was accomplished by protection testing of subcultures in mice.
Microorganisms of the Upper Atmosphere
Authors: Fulton John D.
Published: December 2020

Simultaneous sampling for microorganisms was accomplished at altitudes of 690, 1,600, and 3,127 meters. The location of temperature inversions in relation to the collection altitude determined, to a great extent, the micropopulation. High micropopulations were found when an inversion was above the sampling altitude, and low populations when the inversion was below the sampling altitude. Diurnal periodicity which could be generally correlated with periods of minimal and maximal convective activity was observed. Evidence is presented showing that the micropopulation is more stable at higher altitudes than at lower altitudes.
Pilot Plant Glycerol Production with a Slow-Feed Osmophilic Yeast Fermentation
Authors: Button D. K. , Garver J. C. , Hajny G. J.
Published: December 2020

A slow feed batch fermentation is described for the production of glycerol from sugar. The conversion efficiency was approximately 1 mole of glycerol produced per mole of glucose utilized after the cell growth phase. The glycerol production phase was extended several-fold by periodic glucose addition. The yeast cell count remained constant during this time as limited by phosphate, a deficiency required for an efficient glycerol fermentation. A small amount of phosphate was supplied during the extended fermentation, maintaining an active culture, by the normal autolysis of spent cells. Interfering or inhibitory by-products did not accumulate, and the osmophilic yeasts are tolerant of high glycerol concentrations. These factors combined to allow a particularly efficient fermentation well suited to product enrichment by supplying large quantities of substrate over an extended period.
Phenazines as Disinfectants against Bacterial Leaf Blight of the Rice Plant
Authors: Oda Makoto , Sekizawa Yasuharu , Watanabe Tetsuro
Published: December 2020

A series of phenazine compounds, including 15 synthetics and a natural derivative, iodinin, were tested for inhibition of selected phytopathogenic bacteria and fungi. Eleven of the compounds had bacteriostatic activity for
Xanthomonas oryzae
. Three other species of
Xanthomonas
were resistant. Phenazine 5-oxide was the most effective phenazine against the bacterial leaf blight.
Bacterial Pollution Indicators in the Intestinal Tract of Freshwater Fish
Authors: Geldreich Edwin E. , Clarke Norman A.
Published: December 2020

A study was made of the occurrence, distribution, and persistence of coliforms, fecal coliforms, and fecal streptococci in the intestinal tract of freshwater fish. A total of 132 fish representing 14 different species were used in various phases of these experiments. Examination of the intestinal contents of 78 fish from moderately polluted sections of the Little Miami River indicated that fecal coliform densities were lowest in bluegills (less than 20 per gram) and highest in catfish (1,090,000 per gram). Levels of fecal streptococci for these two species were 220 and 240,000 per gram, respectively. The occurrence of fecal coliforms in fish caught in this stream reflected the warm-blooded-animal-pollution level of the water. All fish used in this phase of the study were caught during July, August, and September when the water temperatures were between 13 and 18 C. The fate of fecal coliforms and
Streptococcus faecalis
in the fish intestine indicated that these organisms can probably survive and multiply when fish and water temperatures are 20 C or higher, but only when the organisms are retained in the gut for periods beyond 24 hr. Based on the biochemical reactions for 3,877 coliform strains isolated from 132 freshwater fish of 14 different species, 91.4% of all strains were composed of five IMViC types. In a similar study of the biochemical reactions of 850 streptococci isolated from the intestinal tract of 55 freshwater fish, the predominant strains included
S. faecalis
and various closely associated biotypes. No consistently recurring pattern for either coliforms or streptococci could be developed to identify species of fish investigated. The composition of the intestinal flora is, however, related in varying degree to the level of contamination of water and food in the environment.
Effect of Pimaricin on the Resistance of
Saccharomyces cerevisiae
to Heat, Freezing, and Ultraviolet Irradiation
Authors: York G. K.
Published: December 2020

Exposure of washed cells of
Saccharomyces cerevisiae
C-299 to inhibitory concentrations of pimaricin decreased resistance to lethal temperatures and to freezing and thawing. Varying the
p
H of the recovery medium had little effect on the decrease in heat resistance, but addition of peptone or yeast extract resulted in a partial recovery of apparent heat resistance. Addition of peptone or calcium ion to the heating menstruum did not affect the reduction in resistance caused by pimaricin. Varying the composition of the recovery medium similarly affected the resistance to freezing the thawing of pimaricin-exposed and unexposed cells. Sensitivity to ultraviolet light was apparently not affected by pimaricin either by preliminary exposure or when irradiated in the presence of pimaricin. It is suggested that pimaricin lowers the heat resistance of
S. cerevisiae
by depleting essential nutrients of the cells through a disruption of permeability, and that heat-damaged cells cannot resynthesize these nutrients. It is also suggested that spoilage of acid foods by
S. cerevisiae
may be retarded by a combination of mild heat treatment and the addition of pimaricin.
Preservation of
Serratia marcescens
by High-Vacuum Lyophilization
Authors: Dewald Robert R.
Published: December 2020

Water-washed
Serratia marcescens
(ATCC strain 14041) cells were lyophilized in an all-glass system capable of evacuation to pressures of less than 5 × 10
-6
torr. Lyophilization at the lowest pressures resulted in 50 to 65% survival for unstabilized washed organisms compared with 10 to 20% when the cells were lyophilized at pressures of about 2.5 × 10
-2
torr. At the latter pressures, 45 to 65% survival was obtained when NaCl or Naylor-Smith stabilizer was added to the cell suspensions before lyophilization. However, the stabilizers failed to increase significantly the levels of survival compared with water suspension when cells were lyophilized at pressures less than 10
-5
torr. The high survival rates obtained by the high-vacuum technique may be attributed to the reduction of traces of molecular oxygen which has been reported to be destructive of the dried bacteria. Survival of unstabilized dried
S. marcescens
after 1-day storage increased markedly with decreasing sealing pressure. Under the highest vacuum attained, survival of the dried bacteria was not impaired by storage for up to 1 month at Dry Ice temperatures; at higher temperatures, viability losses occurred. Exposure of the dried unstabilized bacteria to dry air resulted in rapid viability loss. The inactivation could be stopped almost immediately by evacuation to pressures of less than 10
-5
torr, but the evacuation failed to reverse the viability losses that occurred during exposure.
Cultivation of
Pasteurella haemolytica
in a Chemically Defined Medium
Authors: Wessman G. E.
Published: December 2020

A chemically defined medium was developed for the aerobic cultivation of
Pasteurella haemolytica
. Studies on the growth of strain H44L were conducted in a medium consisting of 15 amino acids, inorganic salts, citrate, nicotinamide, pantothenate, thiamine or thiamine monophosphate, and carbon sources. The amino acids were provided as
l
isomers, because racemic mixtures of some amino acids inhibited growth. The carbon source consisted of a mixture of 1.0%
d
-galactose and 0.1%
d
-glucose. Culture populations of strain H44L reached 2 × 10
10
cells per milliliter after 16 hr of incubation at 37.5 C. Other strains of
P. haemolytica
, from a wide variety of sources, were tested for growth in the medium, and 23 of 24 strains grew well. Five strains of
P. haemolytica
var.
ureae
failed to grow in the medium.
Chemical Characterization of Wines Fermented with Various Malo-lactic Bacteria
Authors: Pilone Gordon J. , Kunkee Ralph E. , Webb A. Dinsmoor
Published: December 2020

Six malo-lactic strains of lactic acid bacteria were isolated from California wines and identified as
Lactobacillus delbrueckii, L. buchneri, L. brevis, Leuconostoc citrovorum
, and two strains of
Pediococcus cerevisiae
. Malo-lactic fermentation was induced in separate lots of wine by inoculation of each lot with one of the strains of bacteria. Malo-lactic fermentation had occurred in each inoculated wine within 2 months. The resultant wines were subjected to chemical analysis, including gas chromatographic examination of concentrated extracts of the wines. Only a few differences in composition were found when the malo-lactic wines were compared one with another. The differences that were found were in volatile acidity and in concentrations of acetoin (plus diacetyl) and probably diethyl succinate.
Effects of Additives on the Survival of Lactic Streptococci in Frozen Storage
Authors: Gibson C. A. , Landerkin G. B. , Morse Pamela M.
Published: December 2020

Three single-strain cultures,
Streptococcus lactis
C
2
,
S. cremoris
R
1
, and
S. diacetilactis
DRC
2
, were frozen and stored in skim milk, in skim milk containing apple juice, and in skim milk containing one of the following additives: glycerol (10%, v/v), dimethyl sulfoxide (10%, v/v),
l
-malic acid (0.5 and 2.0%, w/v), acetamide (0.5 and 2.0%, w/v), or succinimide (0.5 and 2.0%, w/v). Cultures were frozen and stored at -23.3 C, frozen and stored at -196 C in liquid nitrogen, or frozen at -196 C and stored at -23.3 C. Cultures frozen and stored at -196 C in liquid nitrogen gave the greatest recovery of viable cells. The number of cells surviving after storage at -23.3 C was greater when the cells had been frozen in liquid N
2
than when they had been frozen at -23.3 C. All strains stored at -23.3 C showed a decrease in numbers of surviving cells; additives, particularly
l
-malic acid and apple juice, were advantageous in preserving the viability of the
S. lactis
C
2
and
S. cremoris
R
1
strains, but had little or no effect on the survival of
S. diacetilactis
DRC
2
.
l
-Malic acid and apple juice stimulated acid production for all cultures in activity tests following incubation after thawing, whereas glycerol and dimethyl sulfoxide retarded its development.
Improved Motility Medium
Authors: Ball Robert J. , Sellers Walter
Published: December 2020

An improved motility medium which permits additional cultural characterization is described. Advantages include maximal motility due to a change in the physical state of the medium from solid to liquid at incubation temperatures, a definitive stab line, preservation of the stab line with nonmotile organisms, and visual delineation of culture motility. In addition, nitrate reduction, nitrogen gas production, and gelatin liquefaction may be demonstrated.
Comparison of Methods for the Isolation of
Salmonella
from Bone Meal
Authors: Gerichter C. B. , Sechter I.
Published: December 2020

The efficiency of some methods for the isolation of
Salmonella
from bone meal was studied. Grinding of the granulated, industrial product was found to increase
Salmonella
recovery. An improvement in the efficiency of the pre-enrichment method was obtained by adding deoxycholate (1%) to mannitol broth. Selective enrichment in selenite cystine medium gave better results than in Kauffmann-Müller medium, when small inocula were used. Experimental data showed that, in the presence of large numbers of coliforms and very small numbers of
Salmonella
, the Kauffman-Müller medium offers better results, but, in the presence of smaller numbers of coliforms, selenite cystine is preferable. As solid selective medium, Brilliant Green Agar gave, in our laboratory, better results than S S medium.
Thermal Resistance of
Pseudomonas fragi
in Milk Containing Various Amounts of Fat
Authors: Luedecke L. O. , Harmon L. G.
Published: December 2020

Similar populations of
Pseudomonas fragi
were grown at 25 C for 20 hr or at 7 C for 7 days in milk containing 0, 10, and 20% fat; they were then heated at 48, 50, and 52 C in milk containing 0, 10, and 20% fat. After inoculation, the heating medium contained 2.1 × 10
6
to 6.9 × 10
6
organisms per milliliter. The
P. fragi
cells grown in skim milk had greater thermal resistance (
D
52
= 3.0 to 3.1) than those grown in milk containing fat (
D
52
= 1.9 to 2.5). The organisms grown at 7 C for 7 days in milk containing 10% fat were more resistant (
D
52
= 3.0) than those grown in the same medium at 25 C for 20 hr (
D
52
= 2.0). The presence of 0 to 20% milk fat in the heating medium had no apparent effect on the thermal resistance.
Effect of Zytron and Its Degradation Products on Soil Microorganisms
Authors: Fields M. L. , Hemphill D. D.
Published: December 2020

There was no adverse effect of Zytron,
o
-2,4-dichlorophenyl
o
-methyl isopropyl phosphoramidothioate, a herbicide, upon molds, actinomycetes, and soil bacteria in field plots, or upon selected soil microorganisms in model systems. 2,4-Dichlorophenol, a degradation product, was found to be toxic at levels above 10 ppm to molds, but levels this high were not found in soil from treated plots.
Aspergillus clavatus
degraded both Zytron and 2,4-dichlorophenol. Sodium
o
-methyl isopropyl phosphoramidothioate, another degradation product of Zytron, stimulated the growth of a species of
Penicillium
.