bluuebunny/crossref_metadata_2025 huggingface dataset:
System for Detecting Inducers of Lysogenic
Escherichia coli
W1709(λ) and Its Applicability as a Screen for Antineoplastic Antibodies
Authors: Price K. E. , Buck R. E. , Lein J.
Published: December 2020

Studies were conducted to determine conditions of maximal sensitivity for a test system designed to detect chemical inducers of phage production in the streptomycin-dependent, lysogenic
Escherichia coli
strain W1709(λ). This strain was found to be induced by all antibiotics previously reported to be inducers of
E. coli
K-12(λ). However, the system employing W1709(λ) proved superior for screening fermentation filtrates because its growth, in contrast to that of K-12(λ), was not stimulated during the induction period by filtrate nutrients. Thus, misleading high phage counts, which accompany cell growth stimulation, were not produced by filtrates devoid of inducing activity. The inducing capability of 95 fermentation filtrates, each containing an unidentified antibiotic(s) inhibitory for one or more transplanted rodent tumors, was determined in the W1709(λ) system. A low incidence of inducers was found among inhibitors of sarcoma 180, adenocarcinoma 755, solid myeloid leukemia C1498, and adenocarcinoma of the duodenum in the hamster. However, seven of eight filtrates active against leukemia 1210 had induction capability. From a screen of actinomycete culture filtrates, 28 of the first 1,000 were identified as producers of induction activity. Thus far, of the nine cultures from this group that were subjected to examination, eight demonstrated at least presumptive evidence of antineoplastic activity.
Population Dynamics of
Brucella
on Solid Media
Authors: Gibby Irvin W. , Gibby Anna M.
Published: December 2020

An examination is presented of the growth characteristics on solid media of one strain each of
Brucella abortus
and
B. neotomae
. It was observed that, during the exponential growth phase, generation times of approximately 100 min were measured for both organisms under a variety of conditions. The logarithmic growth phase did not extend beyond 18 hr in most instances. It was noted that erythritol added to Trypticase Soy Agar did not enhance the growth rate or the total viable yield of either organism. Phosphate buffer failed to exert a significant effect upon pH changes during culture.
B. neotomae
cultures on solid media produced markedly acidic reactions in 48 hr. If cells in an active growth phase are desired, it is suggested that solid media cultures of laboratory strains be harvested before 24 hr.
Evaluation of Disinfectants for Hospital Housekeeping Use
Authors: Ostrander W. E. , Griffith L. J.
Published: December 2020

A use-dilution procedure and screening method are proposed to aid the hospital bacteriologist in selecting the most effective disinfectants. Sixteen disinfectants were tested with and without organic material on six different organisms. Sporadic results usually obtained with quaternaries tested by the procedure of the Association of Official Agricultural Chemists (AOAC) were eliminated by the methods of this study. The use-dilution procedure employs the material upon which the disinfectant is to be used, rather than stainless steel, as in the AOAC use-dilution test. The importance of testing each disinfectant against several organisms and in the presence of organic material is discussed.
Source and Portal of Entry of Bacteria Found in Bruised Poultry Tissue
Authors: Hamdy M. K. , Barton N. D. , Brown W. E.
Published: December 2020

Bacteriological studies revealed that normal tissue, air sacs, feathers, skin of birds, poultry feed, gut, and chicken droppings were sources of the predominant organisms, including staphylococci, found in bruised poultry tissue. Further investigation of normal tissue revealed that after the intramuscular injection of
Staphylococcus aureus
, marker strain (MS), the organism was eliminated from these tissues within 7 days. However, when these tissues were traumatized 3 days after injection, the number of the test organism increased, and the organism was present on the 7th day after inoculation. Poultry feed and fecal material contained a large number of staphylococci identical to those isolated from bruised tissue (McCarthy, Brown, and Hamdy, 1963), thereby implicating the gut as a possible portal of entry. When a pathogenic marker strain of
S. aureus
was established in the intestinal tract of chickens by administering an active culture of this organism either in their drinking water or by gavage, it was recovered from the traumatized tissue. The incidence of positive culture of
S. aureus
MS in these tissues correlated with age of bruise, reaching 22 to 33% immediately after contusion and at the early stages of healing (1 to 3 days post bruise) and decreasing thereafter from 11 to 0% on the 4th through 6th days after bruise infliction. The air sac was also found to be a site by which bacteria may enter the traumatized tissues, but to a limited extent.
β-Glucosidase Activity in Phytopathogenic Bacteria
Authors: Hildebrand D. C. , Schroth Milton N.
Published: December 2020

Most of 58 isolates of phytopathogenic and related bacteria comprising 24 species in the genera
Agrobacterium, Erwinia, Corynebacterium, Pseudomonas
, and
Xanthomonas
exhibited β-glucosidase activity, especially the gall-nonforming pathogenic pseudomonads and soft rot organisms. The gall-forming pseudomonads and
P. fluorescens
exhibited no β-glucosidase activity, with the exception of one isolate of
P. savastanoi
which showed slight activity on an inorganic nitrogen-arbutin medium. The best medium for demonstrating β-glucosidase activity contained peptone as the nitrogen source and arbutin. β-Glucosidase activity in this medium was indicated by either acid production or browning.
P. syringae
, in contrast to other bacteria tested, produced most β-glucosidase in a medium containing large amounts of glucose. Chromatographic analyses confirmed that splitting of the glucoside occurred at the glucosidic linkage. Reaction of sonically treated bacterial cells with indican or
p
-nitrophenyl-β-D-glucoside proved a rapid method for assaying relative amounts of β-glucosidase among bacterial species. Harda's paper-strip method of detecting β-glucosidase also was useful in revealing the distribution and relative amounts of β-glucosidase in most bacteria, but did not indicate the relatively greater amount of β-glucosidase in
P. syringae
.
Incidence of Salmonellae in Dressed Broiler-Fryer Chickens
Authors: Woodburn Margy
Published: December 2020

Salmonellae were isolated from 72 of 264 broiler-fryer type chickens that had been purchased in retail stores in the Lafayette, Ind., area in 1963. Meat from the tail area and giblet portions were used in sampling. Equal numbers of dressed whole and cut-up birds were positive for salmonellae. Thirteen different serotypes were identified, the more common being
Salmonella infantis, S. reading
, and
S. blockley
. Incubation at 43 C of the blended sample in Selenite-F Enrichment broth containing cystine gave a larger number of recoveries than did incubation at 37 C. There was no significant difference between the means for the birds that yielded salmonellae and those that did not in the locally processed group, when compared for numbers of aerobic microorganisms at 37 C, coliforms, or most probable number of enterococci. In a comparison of poultry processed in-state by the five processors included in the study with that processed out-of-state, there was a general trend for a larger number of positive specimens in the locally produced group. The fall season was an exception.
Lipid Alterations During the Fermentation of Dill Pickles
Authors: Pederson C. S. , Mattick L. R. , Lee F. A. , Butts R. M.
Published: December 2020

Analyses of various lipid fractions of sections of cucumbers and of good and bloated dill pickles showed that marked changes occur in all lipid fractions during fermentation. The most striking difference noted was the decrease in the phospholipid fraction. A nearly fourfold increase in free fatty acid, as well as a marked increase in the neutral fat fatty acids and unsaponifiables, occurred. Gas chromatographic analyses of the methyl esters of fatty acids from the various lipid fractions yielded further interesting data. From the analyses, 41 esters were identified; however, 16 of the esters accounted for at least 95% of the acids. Among the marked changes were the increases in linoleic and linolenic acids in good pickles, in contrast to the increase in oleic acid in the bloated pickles. The presence of tridecenoic acid in cucumbers, and its absence in pickles; and the absence of caproic, caprylic, and capric acids in cucumbers, and its presence in pickles, were interesting. The data demonstrated that the lipid alterations that occur during fermentation of cucumbers are analogous to those previously reported for the sauerkraut fermentation.
Polyphosphate Inhibition of Growth of Pseudomonads From Poultry Meat
Authors: Elliott R. Paul , Straka Robert P. , Garibaldi John A.
Published: December 2020

Both commercial polyphosphates and equivalent mixtures of chemically pure polyphosphates inhibited the growth of nonfluorescent pseudomonads in a synthetic medium. Fluorescent strains grew after a short lag. Inhibition was not caused by high pH, but rather by chelation of metal ions essential to the growth of the bacteria. Mg
++
and the natural competitive chelators, pyoverdine and bacteriological peptone, reversed the inhibition. Chilling chicken carcasses overnight in slush ice containing 3 and 8% polyphosphates lengthened subsequent shelf-life 17 and 25%, respectively. Chickens held in continuous contact with 3 and 8% solutions of polyphosphates during storage at 2.2 C kept 17 and 67% longer, respectively. Only fluorescent strains developed in the presence of 3 and 8% polyphosphates. Chickens held in antiseptic ice containing 8% polyphosphates kept 60% longer than did those in water ice.
Pure Culture Fermentation of Brined Cucumbers
Authors: Etchells J. L. , Costilow R. N. , Anderson T. E. , Bell T. A.
Published: December 2020

The relative abilities of
Pediococcus cerevisiae, Lactobacillus plantarum, L. brevis
, and several other species of lactic acid bacteria to grow and produce acid in brined cucumbers were evaluated in pure culture fermentations. Such fermentations were made possibly by the use of two techniques, gamma radiation (0.83 to 1.00 Mrad) and hot-water blanching (66 to 80 C for 5 min), designed first to rid the cucumbers of naturally occurring, interfering, and competitive microbial groups prior to brining, followed by inoculation with the desired lactic acid bacteria. Of the nine species tested, strains of the three common to cucumber fermentations,
P. cerevisiae, L. plantarum
, and
L. brevis
, grew to the highest populations, and produced the highest levels of brine acidity and the lowest pH values in fermentations at 5.4 to 5.6% NaCl by weight; also, their sequence of active development in fermentations, with the use of a three-species mixture for inoculation, was in the species order just named. This sequence of occurrence was similar to that estimated by others for natural fermentations. The rates of growth and acid production in fermentations with a mixture of
P. cerevisiae, L. plantarum
, and
L. brevis
increased as the incubation temperature was increased from 21 to 27 to 32 C; however, the maximal populations and acidities attained were essentially the same for fermentations at each temperature. Further, these same three species were found to be the most salt tolerant of those tested; their upper limit for appreciable growth and measurable acid production was about 8% salt, whereas thermophilic species such as
L. thermophilus, L. lactis, L. helveticus, L. fermenti
, and
L. delbrueckii
exhibited a much lower salt tolerance, ranging from about 2.5 to 4.0%. However, certain strains of
L. delbrueckii
grew very rapidly in cucumbers brined at 2.5 to 3.0% salt, and produced sufficient acid in about 30 hr at 48 C to reduce the brine pH from above 7.0 to below 4.0. An inexpensive, pure culture fermentor which was suitable for gamma radiation, resistant to salt and acid, and which permitted repeated aseptic sampling of the fermenting brine, is illustrated and the specifications are given.
Effects of Corn Steep Liquor and Thiamine on
l
-Glutamic Acid Fermentation of Hydrocarbons
Authors: Takahashi Joji , Kobayashi Kaetsu , Imada Yukio , Yamada Koichi
Published: December 2020

The effect of nutrients of natural source, such as corn steep liquor, peptone, and yeast extract, on the fermentative production of L-glutamic acid from hydrocarbons by a
Corynebacterium
was studied. Corn steep liquor and meat extract were found to be remarkably stimulatory to L-glutamic acid production; about 5 g per liter of L-glutamic acid were accumulated in a culture broth containing 3%
n
-paraffins, 0.01% corn steep liquor, and mineral salts. Among nutritional factors contained in corn steep liquor, biotin had very little effect on the accumulation of L-glutamic acid, but thiamine was highly stimulatory to L-glutamic acid production. The optimal concentration of thiamine for L-glutamic acid production was 3 to 5 μg per liter, and for cell growth, 50 μg per liter. L-Glutamic acid was accumulated in negligible quantity when the amount of thiamine in the culture broth was sufficient to support abundant growth of bacterial cells.
Enrichment Procedure for Use with the Membrane Filter for the Isolation and Enumeration of Fecal Streptococci in Water
Authors: Rose Robert E. , Litsky Warren
Published: December 2020

By the use of PYC enrichment medium, the recovery of fecal streptococci from river water has been increased more than twofold over that of M-Enterococcus Agar. Of the isolates tested, 94.6% could be classified as enterococci or enterococcus biotypes. This method seems to yield a larger number of strains which would not normally be revealed. Serological typing of atypical streptococcus strains isolated indicates that the majority of these “biotypes” can be placed in the enterococcus group.
Effect of Oxygen-Supply Rates on Growth of
Escherichia coli
Authors: McDaniel L. E. , Bailey E. G. , Zimmerli A.
Published: December 2020

Growth of
Escherichia coli
and chemical changes in the medium were very similar in highly baffled flasks and in a 50-liter fermentor run under the same oxygen-supply conditions, based on sulfite-oxidation rates. Flasks with stainless-steel baffles (Biotech) gave growth patterns and rates of glucose and NH
4
-N utilization almost identical to those of the fermentor; results with Bellco 598 flasks (with 6 to 7 mm deep indentations) were quite similar. Unbaffled and Bellco 600 flasks (3 to 4 mm indentations) were similar to the fermentor at very high and very low oxygen-transfer rates, but gave much less growth than the fermentor at intermediate levels. Maximal oxygen-uptake rates occurred in the fermentor at the end of the logarithmic-growth phase when growth was 40 to 75% of maximum. In the fermentor, both sulfite-oxidation rates and rates of oxygen uptake correlated reasonably well with the total amount of growth produced.
Color and Streptomycetes
Authors: Pridham Thomas G.
Published: December 2020

A report summarizing the results of an international workshop on determination of color of streptomycetes is presented. The results suggest that the color systems which seem most practically appealing and effective to specialists on actinomycetes are those embracing a limited number of color names and groups. The broad groupings allow placement of isolates into reasonably well-defined categories based on color of aerial mycelium. Attempts to expand such systems (more color groups) lead to difficulties. It is common knowledge that many, if not all, of the individual groups would in these broad systems contain strains that differ in many other respects, e.g., spore-wall ornamentation, color of vegetative (substratal) mycelium, morphology of chains of spores, and numerous physiological criteria. Also, cultures of intermediate color can be found, which makes placement difficult. As it now stands, color as a criterion for characterization of streptomycetes and streptoverticillia is in questionable status. Although much useful color information can be obtained by an individual, the application of this information to that in the literature or its use in communication with other individuals leaves much to be desired. More objective methods of color determination are needed. At present, the most effective method that could be used internationally is the color-wheel system of Tresner and Backus. Furthermore, the significance of color in speciation of these organisms is an open question. Obviously, more critical work on the color problem is needed.
Effect of Various Concentrations of Brilliant Green and Bile Salts on Salmonellae and Other Microorganisms
Authors: Miller V. Richard , Banwart George J.
Published: December 2020

A study of the inhibitory effect of 24 different combinations of brilliant green and bile salts concentrations was conducted, using seven species of microorganisms capable of fermenting mannitol. The inhibitory effect of brilliant green decreased as the bile salts concentration was increased.
Staphylococcus aureus
and
Proteus rettgeri
were inhibited by all test media.
Escherichia coli
was inhibited in all but two combinations of brilliant green and bile salts.
Aerobacter aerogenes
generally followed a pattern of growth similar to that of three species of salmonellae. Three of the 24 combinations of brilliant green and bile salts showed little or no inhibition of salmonellae but did inhibit the other organisms studied.
Chlortetracycline and Oxytetracycline Residues in Poultry Tissues and Eggs
Authors: Meredith W. E. , Weiser H. H. , Winter A. R.
Published: December 2020

A pad-plate method of assaying residual amounts of chlortetracycline (CTC) and oxytetracycline (OTC) using
Bacillus cereus
213 was used to determine amounts of antibiotic left in tissues and eggs of poultry fed 1,000 and 200 ppm of CTC and OTC in basal feed mixtures. The effects of various methods of cooking the tissues and eggs and the potentiating effect of terephthalic acid (TPA) were studied. It was found that normal methods of roasting, frying, and autoclaving poultry tissue destroyed all residual CTC and OTC, even with the potentiating effect of TPA. The largest amounts of residual antibiotic were found in the liver, then breast, and then thigh tissue when assayed for CTC. Tissue assays for CTC revealed that it was not taken up as extensively as CTC and the largest amounts were found in the liver, then breast. OTC residue was seldom found in the thigh tissue. Terephthalic acid in 0.5% concentration increased the concentration found in all cases. Cooking by poaching and scrambling eggs did not destroy the antibiotic in all cases.
Characteristics and Pathogenicity of a Capsulated
Pseudomonas
Isolated from Goldfish
Authors: Bullock Graham L.
Published: December 2020

Characteristics of a capsulated bacterium isolated from an epizootic among goldfish (
Carassius auratus
) were determined as well as the ability of the bacterium to produce experimental infections. The bacterium was found to be a gram-negative rod which oxidized carbohydrates, produced green fluorescent pigment, and otherwise seemed to fit into the genus
Pseudomonas
, except that it was nonmotile and failed to oxidize gluconate. These last two characteristics are typical of pseudomonads. However, the bacterium was classified as a pseudomonad, best fitting the description of the nonmotile variety of
Pseudomonas fluorescens
. Goldfish and rainbow trout (
Salmo gairdneri
) were infected experimentally by injection, but not by being fed bacteria-laden food. Goldfish were infected by exposure to the bacterium, but only if two or three scales were removed prior to exposure. It is suggested that the bacterium is an opportunistic pathogen.
New Method for Purifying
Coxiella burnetii
by Dextran Sulfate Precipitation Followed by Centrifugation
Authors: Davis J. L. , Patrick W. C.
Published: December 2020

This paper describes a simple method for purifying
Coxiella burnetii
cultivated in the chick embryo. The procedure is based upon the preliminary clarification of infected whole-egg suspensions by precipitating the low-density lipoproteins and other extraneous solids with dextran sulfate, calcium chloride, and sodium chloride solutions, and then concentrating the rickettsiae by centrifugation.
Automatically Recording Respirometer
Authors: Arthur Robert M.
Published: December 2020

Recently, several different types of devices have been developed which automatically record oxygen consumption of biological cultures. This article describes one of these devices and discusses its application.
Erwinia
-Like Microorganisms Isolated from Animal and Human Hosts
Authors: Muraschi Thelma F. , Friend Milton , Bolles Dorothy
Published: December 2020

Erwinia
-like microorganisms were isolated from the vital organs of more than 40% of a large deer population examined as well as from 13% of a small random sampling. Over a brief period of observation, a similar isolate was recovered from throat cultures of two children and one adolescent. There is no obvious explanation of the presence of the plant pathogen or its significance under these circumstances.
Physicochemical and Biological Studies on Various Preparations of Tuberculin Purifield Protein Derivative
Authors: Landi S. , Held H. R.
Published: December 2020

Tuberculin purified protein derivative (PPD) has been prepared by seven different precipitation methods from culture filtrate of
Mycobacterium tuberculosis
var.
hominis
. It was found to contain 48 to 99% tuberculoprotein, depending on the method of precipitation. The remaining percentage is represented by nucleic acid, polysaccharide, and ash. Activation analysis on tuberculin PPD and on tubercle bacilli has revealed the presence of trace elements. The molecular weight of tuberculin PPD has been found to be of the order of 14,800 to 27,800. The biological activity of tuberculin PPD varies from lot to lot and from method to method. A correlation between its molecular weight and its biological activity seems to exist.
Vigorous Mold Growth in Soils After Addition of Water-Insoluble Fatty Substances
Authors: Krause Frank P. , Lange Willy
Published: December 2020

Various water-insoluble fatty compounds, when added to soil in finely divided form, will support as high-caloric nutrients a visible, vigorous growth of the molds,
Fusarium solani
Mart.,
F. diversisporum
Sherb., and
F. equiseti. n
-Paraffins and olefins are most effective, because the effect of additives is reduced to the extent that oxygen atoms are introduced into the molecule.
n
-Fatty alcohols support growth in soil almost as well as the paraffins; however, growth is reduced when branched-chain compounds are added as nutrients. Compounds that will support mold growth when added to air-dried soil as finely powdered solids will not do so when incorporated at temperatures above their melting point, but will produce dense growth when applied to wet soil in this form. Mold growth is correlated with degradation of fatty matter. The rate of degradation is controlled by the availability of water, oxygen, and the basic inorganic nutrients.
Role of
Leuconostoc mesenteroides
in Leavening the Batter of Idli, a Fermented Food of India
Authors: Mukherjee S. K. , Albury M. N. , Pederson C. S. , Van Veen A. G. , Steinkraus K. H.
Published: December 2020

The fermentation of the batter of idli, a fermented food of India, was studied. The microorganisms responsible for the characteristic changes in the batter were isolated and identified. Although there is a sequential change in the bacterial flora, the predominant microorganism responsible for souring, as well as for gas production, was found to be
Leuconostoc mesenteroides
. In the later stages of fermentation, growth of
Streptococcus faecalis
and, still later, of
Pediococcus cerevisiae
becomes significant. The fermentation of idli demonstrates a leavening action caused by the activity of the heterofermentative lactic acid bacterium,
L. mesenteroides
. As far as is known, this is the first record of a leavening action produced exclusively by the activity of a lactic acid bacterium.
Resistance of
Clostridium perfringens
Type A Spores to γ-Radiation
Authors: Midura T. F. , Kempe L. L. , Graikoski J. T. , Milone N. A.
Published: December 2020

The radiation resistance of the spores of a classical strain and of an atypical, heat-resistant strain of
Clostridium perfringens
was determined. Spores were produced in Ellner's and in a Trypticase broth medium. Approximately 10
6
viable spores per milliliter were suspended in 0.06
m
phosphate buffer and irradiated with γ rays from cobalt-60; the survivors were counted in Tryptone-yeast extract-agar by the Prickett-tube technique. Radiation
D
values for spores of the atypical strain in phosphate buffer and in cooked-meat broth were 0.23 and 0.30 Mrad, respectively, and the
D
value of the classical strain was 0.25 Mrad in phosphate buffer. Spores of the classical and atypical strains of
C. perfringens
type A are characterized by differences in heat resistance; yet, all strains tested demonstrated similar radiation resistance. Also, the spores were more resistant to ionizing radiation in cooked-meat broth than in phosphate buffer.
In Vitro and In Vivo Laboratory Evaluation of Cephaloglycin and Cephaloridine
Authors: Wick Warren E. , Boniece William S.
Published: December 2020

Two new antibiotics, structurally related to cephalothin, have been given the generic names cephaloglycin and cephaloridine. Cephaloglycin is the dipolar ion of 7-(
d
-α-aminophenylacetamido)-cephalosporanic acid. Cephaloridine is 7-[α-(2-thiophene)acetamido]-3-(1-pyridylmethyl)-3-cephem-4-carboxylic acid betaine. These new compounds were evaluated simultaneously. The broad spectrum of activity observed in vitro and in vivo with both antibiotics, the good oral absorption obtained with cephaloglycin, and the stability of cephaloridine are emphasized. The data suggest that both antibiotics merit clinical trial in humans.
Pouch Method for the Isolation and Enumeration of Clostridia
Authors: Bladel B. O. , Greenberg Richard A.
Published: December 2020

An anaerobic film-pouch method has been developed for the isolation and enumeration of clostridia. Fabrication of the pouch is described. Counts of spore suspensions of Putrefactive Anaerobe 3679 and of
Clostridium botulinum
strains 41-B and 33-A in pouches were compared with those obtained by anaerobic-jar and agar-deep techniques. Statistical analysis revealed a significant difference in favor of the pouch over the tube and anaerobic-jar methods. Tests performed with
C. welchii
, both in spore suspension and added to chicken pot pie in culture form, also demonstrated the pouch to be at least as proficient as the other, more cumbersome, techniques.
Rapid Graphical Method for Estimating the Precision of Direct Microscopic Counting Data
Authors: Cassell E. Alan
Published: December 2020

A graphical method of estimating the 90, 95, or 99% confidence intervals of direct microscopic counting data is presented. Construction of the graphs is based on the assumption that the normal distribution approximates the Poisson distribution. The method, useful on data obtained from dried films or counting chambers, eliminates time-consuming computation of precision. The minimal number of fields which must be counted to maintain a certain level of precision can be readily determined.
Agar-Gel Precipitin-Inhibition Technique for C-Reactive Protein Determinations
Authors: Shay Donald E. , Ray John G.
Published: December 2020

A quantitative C-reactive protein serological procedure has been developed. By use of this method, which is performed in agar-gel plates, from 2 to 654 μg of C-reactive protein per ml of titrated human serum can be detected. The method is based on the inhibition of a specific C-reactive protein antigen-antibody precipitate formed in agar-gel by the minimal reactive dilutions of each reagent in 48 hr. It is simple, sensitive, and readily reproducible.
Clostridium perfringens
in Meat and Meat Products
Authors: Hall Herbert E. , Angelotti Robert
Published: December 2020

A total of 262 specimens of meat and meat dishes were examined for the presence of
Clostridium perfringens
. Of this total, 161 were raw, unprocessed beef, veal, lamb, pork, or chicken; 101 were processed meats and meat dishes.
C. perfringens
was isolated from 113 (43.1%) of these specimens. The highest percentage of contamination (82%) was found in veal cuts, and the lowest (4.7%) in sliced sandwich meats and spreads. Only 2 of the 113 isolates were shown to produce heat-resistant spores, which indicates a very low incidence (0.8%) of contamination. These findings indicate that outbreaks of
C. perfringens
food-borne disease in the Cincinnati area are caused principally by the contamination of the food with vegetative cells or spores of the organism after cooking. Studies of the effects of various holding temperatures on the growth of
C. perfringens
indicated that, in the range of 5 to 15 C, no multiplication would occur, but that viable cells would still be present at the end of a 5-day holding period. Extremely rapid growth occurred at temperatures around 45 C, and complete inhibition of growth was accomplished between 49 and 52 C.
Influence of Temperature on Bacterial Infection of the Hen's Egg
Authors: Board R. G. , Ayres J. C.
Published: December 2020

Temperature of incubation had a marked effect on infection of eggs in which the air cells had been inoculated with a washed suspension of
Serratia marcescens
. There was no evidence of bacterial multiplication or spoilage in eggs held at 10 C for 42 days. Multiplication occurred in the shell membranes of eggs held at 30 or at 37 C when the yolk made contact with these membranes, and continued in the contents of the egg, at which time the first signs of spoilage appeared. In a few eggs, very large populations were present in the shell membranes and in the albumen. In eggs inoculated with
Pseudomonas fluorescens
and held at 10 C, bacterial multiplication occurred in the shell membranes in the first 7 days of incubation. These populations did not appear to change in size in the 7- to 14-day period of incubation. Renewed multiplication and concomitant spoilage of the contents was observed in many of the eggs thereafter.
Isolation of Salmonellae by Selective Motility Systems
Authors: Stuart Philip F. , Pivnick Hilliard
Published: December 2020

Salmonellae were isolated from naturally infected swine and human feces by means of selective migration through semisolid enrichment (SM) media in modified “U” tubes. Comparative studies showed that recovery of
Salmonella
by SM techniques was equal or superior to that of standard procedures employed in two routine diagnostic laboratories. Primary
Salmonella
isolations from SM enrichment were relatively free from normal fecal bacteria and often pure. The SM method required only 15% of the media and correspondingly less time and skill than the usual methods for isolating
Salmonella
.
Production of 2-Ketogluconic Acid by
Serratia marcescens
Authors: Misenheimer T. J. , Anderson R. F. , Lagoda A. A. , Tyler D. D.
Published: December 2020

Production of 2-ketogluconic acid from glucose by fermentation with
Serratia marcescens
NRRL B-486 was studied in 20-liter stainless-steel fermentors. Conditions for 2-ketogluconic acid production included the following: glucose-salt medium, aeration rate of 0.75 volumes per volume per minute, agitation rate of 400 rev/min, temperature of 30 C, CaCO
3
to neutralize the acid formed, and a 5% (v/v) inoculum. Foaming was controlled with an antifoam agent added at intervals during the fermentation. When 120 g per liter of glucose were supplied, 95 to 100% yields of 2-ketogluconic acid were obtained in 16 hr. Larger amounts of glucose could be used in the fermentation provided that the carbohydrate was fed continuously. Continuous feeding of glucose to a total amount of 180 g per liter gave 95 to 100% yields of 2-ketogluconic acid in 24 hr; feeding glucose to a total amount of 240 g per liter gave 85 to 90% yields in 32 to 40 hr.
Heterotrophic Growth and Production of Xanthophylls by
Chlorella pyrenoidosa
Authors: Theriault Robert J.
Published: December 2020

The growth and level of xanthophylls of several representative species of green algae were investigated as a possible source of pigmentation for the egg yolk and broiler markets.
Chlorella pyrenoidosa
7-11-05 was selected for fermentation studies because of its high level of xanthophylls and wide temperature range for growth. The heterotrophic metabolism was preferred because of the ease of adaptability to present fermentation equipment. When used as the sole carbon source, glucose was the only sugar, among many tested, that gave appreciable growth in illuminated shaken flasks. A dry cell weight of 90 g per liter and total xanthophylls of 450 mg per liter were obtained from 190 g per liter of glucose monohydrate in 168-hr illuminated shaken flasks. Higher levels of glucose decreased yields. In combination with glucose, monosaccharides, such as fructose and galactose, were readily assimilated. The 7-11-05 strain was adapted to galactose as the sole carbon source after six vegetative passages. Light of the proper intensity and duration stimulated total xanthophylls approximately 35%. The effect on dry cell weight and total xanthophylls of seven antibiotics added at various levels in shaken flasks was studied. Erythromycin was essentially stable throughout the fermentation and nontoxic up to 25 μg/ml, with only slight toxicity at higher levels. Both erythromycin and ristocetin were effective in controlling a high incidence of bacterial contamination in 30-liter fermentors. With the higher agitation and aeration rates possible in 30-liter fermentors, dry cell weights in excess of 100 g per liter and total xanthophylls of 467 to 512 mg per liter were readily obtained from 230 to 260 g per liter of glucose in 162-hr illuminated batch-type fermentations. Continuous-feed runs yielded a dry cell weight of 302 g per liter and total xanthophylls of 650 mg per liter from 520 g per liter of glucose. The type of
Chlorella
cell produced was an important consideration with respect to the availability of the xanthophylls in pigmenting egg yolks and broilers.
Factors in the Membrane Filtration of Enteroviruses
Authors: Cliver D. O.
Published: December 2020

The filtration of two species of enteroviruses through membranes of porosity ranging from 50 to 220 mμ was studied. It was shown that extensive or total losses of virus may attend filtration at these porosities, apparently owing to adsorption of the virus to the membrane matrix. This could be minimized by the incorporation of serum into the virus suspension at the time of filtration, or by pretreating the membrane with serum or with a gelatin solution. It was also found that the first few drops of filtrate, even under optimal conditions, were likely to be virus-free, so that the filtration of too small a volume of virus suspension would result in a relatively great loss of titer. The degree to which these factors were critical was found to decrease with increasing pore diameter.
Cultivation of
Pasteurella haemolytica
in a Casein Hydrolysate Medium
Authors: Wessman G. E.
Published: December 2020

The growth of
Pasteurella haemolytica
strain H44L was studied under aerobic conditions in a medium of acid-hydrolyzed casein, supplementary cysteine, inorganic salts, vitamins, and a carbon source. The concentration of casein hydrolysate necessary for optimal growth was 1.5 or 2.0%, depending upon the carbon source employed. Essential vitamins were calcium pantothenate, nicotinamide, and thiamine. Concentrations as low as 0.01 μg/ml of thiamine monophosphate or thiamine pyrophosphate supported maximal growth, but thiamine hydrochloride or thiamine nitrate were active only at the unusually high levels of 10 to 20 μg/ml. The best carbon sources were
d
-galactose or sucrose. Maximal growth resulted from an inoculum containing fewer than 10 cells per milliliter of medium. Cellular yields averaged 6 × 10
9
to 7 × 10
9
cells per milliliter for the test organism and five other strains of
P. haemolytica
isolated from cases of bovine respiratory diseases.
Microbial Degradation of Isopropyl-
N
-3-Chlorophenylcarbamate and 2-Chloroethyl-
N
-3-Chlorophenylcarbamate
Authors: Kaufman D. D. , Kearney P. C.
Published: December 2020

Microbial degradation of isopropyl-
N
-3-chlorophenylcarbamate (CIPC) and 2-chloroethyl-
N
-3-chlorophenylcarbamate (CEPC) was observed in a soil perfusion system. Degradation in perfused soils, and by pure cultures of effective bacterial isolates, was demonstrated by the production of 3-chloroaniline and the subsequent liberation of free chloride ion. Identified isolates effective in degrading and utilizing CIPC as a sole source of carbon included
Pseudomonas striata
Chester, a
Flavobacterium
sp., an
Agrobacterium
sp., and an
Achromobacter
sp. Identified isolates, effective in degrading and utilizing CEPC as a sole source of carbon, included an
Achromobacter
sp. and an
Arthrobacter
sp. CIPC-effective isolates degraded CEPC more slowly than CIPC, whereas CEPC-effective isolates degraded CIPC more rapidly than CEPC. Both CIPC- and CEPC-effective isolates degraded isopropyl
N
-phenylcarbamate (IPC) more rapidly than either CIPC or CEPC.
Freeze-Drying of Foot-and-Mouth Disease Virus and Storage Stability of the Infectivity of Dried Virus at 4 C
Authors: Fellowes O. N.
Published: December 2020

Foot-and-mouth disease virus, type A, strain 119, propagated in cultures of calf kidney cells and in the tongue epithelium of cattle was used. The process of freeze-drying was conducted in two cycles on unit volumes of 4 ml in Pyrex ampoules, averaging 150 ampoules per run, and was studied separately from the problems of storage. Ampoules containing freeze-dried virus were flame-sealed for either immediate study or storage at 4 C for later reference. Tissue-culture virus dried with various additives had a mean processing loss of 0.8 log LD
50
per ml for six different preparations. Virus freeze-dried in tissue suspension had a mean loss of 0.8 log LD
50
per ml for three different preparations. A second set of preparations was processed and specifically studied for storage quality at 4 C. The virus in 14 freeze-dried tissue-culture preparations had a mean loss of 0.75 log LD
50
per ml while stored at 4 C for 1 year. Virus in four freeze-dried tissue suspensions had a mean loss of 0.05 log LD
50
per ml held at 4 C for 1 year. None of the specific additives used for conservation of the virus during the freeze-drying process or during storage at 4 C contributed significantly to the stability of the virus preparations over and above that observed with the normal growth medium of the tissue culture or the ordinary diluents used in making suspensions of tissue virus.
Carbon Dioxide Effects on Glucose Catabolism by Mixed Microbial Cultures
Authors: Gaffney Peter E.
Published: December 2020

Results have shown that, with mixed culture (sewage) inocula, the lag period in aerobic catabolism of glucose can be reduced by increased CO
2
tension. Conversely, removal of CO
2
from the air supply to the growth flasks and Warburg vessels may increase the lag period.
Application of Polarizing Microscopy to Medical Mycology
Authors: Kilton Roger M.
Published: December 2020

The hyphae of 15 species of fungi were cultivated by conventional slide-culture technique and then examined by polarizing microscopy. Extinction angles exhibited by the anisotropic chitin in the cell walls of hyphae were, as a rule, measurable within a minimal growth range of 2 to 3 days after inoculation to slide culture. Of the 15 species examined, 8 saprophytic fungi were found to possess a range of common extinction angles (10° ± 2°). The remaining seven organisms implicated as pathogens were found to possess a range of common extinction angles (20° ± 2°). There appears to be a correlation existing between the pathogenic nature of the examined fungi and their extinction angles, as demonstrated by the polarizing microscope.
Rapid Technique for the Enumeration of
Clostridium perfringens
Authors: Marshall Robert S. , Steenbergen J. Frank , McClung L. S.
Published: December 2020

A new medium, Tryptone-sulfite-neomycin (TSN) agar, and an incubation procedure for the enumeration of
Clostridium perfringens
are described. Tolerance to neomycin, optimal growth at 46 C, and sulfite-reducing properties of
C. perfringens
were used as a basis for development of the medium. Comparisons were made between sulfite-polymyxin-sulfadiazine (SPS) agar and TSN agar at 37 and 46 C with
C. perfringens
and other organisms. These studies indicate the quantitative and selective superiority of TSN agar, incubated at 46 C, over SPS agar.
Sequential Primary and Secondary Shunt Metabolism in
Penicillium chrysogenum
Authors: Taber W. A. , Tertzakian G.
Published: December 2020

Penicillium chrysogenum
was grown on a rich medium and on a more sparse medium which favored penicillin production. Mycelia grown on both media were examined for changes in lipid, mannitol, erythritol, glycerol, pentitol, trehalose, and residual mycelium, and the filtrates were examined for penicillin. Penicillin production took place after the bulk of trehalose, polyol, and lipid had accumulated, and hence the sequential pattern of primary and secondary shunt metabolism, as observed in the case of ergot alkaloid production by
Claviceps purpurea
, was demonstrated in this example of penicillin production.
Metabolism of Barbital by
Streptomyces mediterranei
Authors: Kluepfel D. , Lancini G. C. , Sartori G.
Published: December 2020

The metabolism of barbital in cultures of
Streptomyces mediterranei
was studied. Small quantities were transformed during the fermentation. Four compounds were isolated and identified as 5-ethyldialuric acid, 5-ethylbarbituric acid, 5-(β-hydroxyethyl)-5-ethylbarbituric acid, and diethylmalonic acid monoureid. The influence of these compounds on the production of rifamycin was of minor importance. With the aid of C
14
-barbital, it was established that neither barbital nor any of its metabolic products can be considered as precursors of the rifamycin B.
Bacteriology of Spoilage of Fish Muscle
Authors: Lerke Peter , Adams Ralph , Farber Lionel
Published: December 2020

A total of 807 bacterial isolates from fresh and spoiling fillets of English sole (
Parophrys vetulus
) stored at 5 C were classified as to genus and tested for various biochemical activities, including the ability to spoil sterile muscle press juice at 5 C. Production of off-odor, volatile reducing substances, and trimethylamine was used to estimate spoilage. It was found that (i) spoilers could be distinguished from nonspoilers on the basis of the juice spoilage test, (ii) differentiation between spoilers and nonspoilers could not be achieved by means of the usual biochemical tests, (iii) no micrococci, flavobacteria, and “coryneforms” were spoilers, (iv) certain specific subgroups of the genus
Pseudomonas
consisted exclusively of spoilers whereas others were inactive, (v) the genus
Achromobacter
likewise consisted of spoilers and nonspoilers, and (vi) “coliforms” could produce spoilage. It was concluded that a method is now available to determine directly and unequivocally the role played in spoilage by various bacterial groups and that it is no longer necessary to rely on indirect evidence.
Repression of
Staphylococcus aureus
in Associative Culture
Authors: Iandolo John J. , Clark Carol W. , Bluhm Leslie , Ordal Z. John
Published: December 2020

The growth of
Staphylococcus aureus
MF 31 was suppressed when grown in association with
Streptococcus diacetilactis
and other lactic streptococci. The data indicated that the initial proportion of staphylococci present in the medium was of less importance than the depletion of vital nutrients. Investigation revealed that factors present in Yeast Nitrogen Base medium could reverse the inhibition which was due to antagonism. The major factor found was nicotinamide, and further study revealed that the biological availability of this compound was influenced by the
p
H of the medium. The addition of nicotinamide to depleted media with careful control of the
p
H resulted in increased growth of
S. aureus
in the test system. Further data indicated that additional factors may affect the degree of growth by
S. aureus
in depleted media.
Effect on the White Rat Uterus of a Toxic Substance Isolated from
Fusarium
Authors: Christensen C. M. , Nelson G. H. , Mirocha C. J.
Published: December 2020

Eighty-five fungi isolated from prepared feed and from corn collected on farms were grown separately in moist autoclaved corn. The corn was fed to virgin weanling rats for 5 to 12 days; the rats were then killed, and their uteri were removed and weighed. Twelve isolates of
Fusarium
from corn and one from poinsettias caused increases of five to eight times in weight of the uterus as compared with controls that were fed sound corn. The greatest increase in weight of the uterus was caused by corn inoculated with
Fusarium
No. 5 incubated for 21 days at 20 to 25 C followed by 14 days at 12 C. Extraction of this corn with methylene chloride, separation into fractions by means of a silicic acid column, and further purification by thin-layer chromatography yielded a compound with ultraviolet-absorption maxima at 314, 274, and 236 mμ.
Effect of Different Seawaters on the Development of Biochemically Deficient Mutants of
Serratia marinorubra
Authors: Carlucci A. F. , Silbernagel S. B.
Published: December 2020

The effect of different seawaters on survival and growth of biotin-, isoleucine-, and uracil-requiring mutants of the marine bacterium,
Serratia marinorubra
, has been investigated. Samples of seawater were collected from coastal waters, the California Current, and central North Pacific waters at depths of 1, 25, 50, 100, 250, and 500 m. The growth or survival of the test bacterium in basal medium prepared in these seawater samples was determined. The control water was synthetic or charcoal-treated natural seawater. In several experiments, the metabolite required by the bacterium was added to the basal medium 24 hr after inoculation, and the growth response was determined. Depending on the source, the seawater samples were both stimulating and inhibitory. Surface waters were more inhibitory than those taken at depth, where, in some cases, bacterial growth occurred. Seawater inhibition was related more to station depth than to the location of the station. The most toxic effects were found against the uracil-requiring mutant; the least, against the isoleucine-requiring mutant. The results of these studies and some laboratory experiments indicate that seawater toxicity is not primarily associated with the physical and biological properties of a particular water mass and that the same factor(s) may be responsible for the rapid death of bacteria in all waters.
Fermentation Studies with
Streptomyces griseus
Authors: Shirato Shiroh , Nagatsu Chizuko
Published: December 2020

The effects of four carbon sources and inorganic phosphate on the production of streptomycin and protease by a strain of
Streptomyces griseus
were studied. Protease production was increased in fermentations with comparatively rapid consumption of carbohydrate, and streptomycin was produced under conditions of moderately slow consumption. Starch was consumed more rapidly than glucose, and, in fermentations with starch as a carbon source, good yields of protease were associated with poor yields of streptomycin. The effect of the concentration of inorganic phosphate varied with the sugar source; the rate of consumption of glucose or fructose increased with the addition of inorganic phosphate, and the utilization of starch or maltose was not affected.