bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Sodium Chloride Concentration in an Agar Medium on Growth of Heat-Shocked
Staphylococcus aureus
Authors: Busta F. F. , Jezeski J. J.
Published: December 2020

The numbers of
Staphylococcus aureus
196E surviving heat treatment in milk for various times at 60 C were determined by plate count with normal and modified Staphylococcus Medium No. 110 (S-110), with Plate Count Agar (PCA), and by milk enrichment techniques. Portions of specific heated samples appeared to contain lower populations of
S. aureus
196E when the survivors were enumerated with normal S-110 than with PCA. Similarly, the times at 60 C needed for total destruction of the culture suspension in the test milk appeared to be shorter when survival was determined with normal S-110 agar. The apparently lower thermal death times were found to be related to the NaCl content of the S-110 medium, because use of S-110 agar containing lesser concentrations of NaCl resulted in growth of larger numbers of heat-shocked
S. aureus
196E.
Preparation, Purification, and Stability of Tuberculin
Authors: Landi S.
Published: December 2020

The method used to produce “Connaught” tuberculin purified protein derivative (PPD) is described. The tuberculin PPD for the multiple-puncture method was shown to be stable for at least 24 months at 5 C; tuberculin PPD for the intracutaneous method was shown to be stable at 5 C and 24 C for a period of 18 months in the presence of Tween 80. Evans blue or brillant vital red was added to tuberculin PPD for improved testing by the multiple-puncture method. These tinted tuberculin preparations were found to be as stable as the Connaught tuberculin PPD preparations without dye at 5 C. Freeze-dried tuberculin PPD with Plasdone as an inert base was found to be remarkably stable for a period of at least 24 months at 5, 24, and 37 C.
Some Factors Influencing Acid Production by an Oxytetracycline-Resistant Strain of
Streptococcus lactis
Authors: Mikolajcik E. M. , Harper W. J. , Gould I. A.
Published: December 2020

Induction of oxytetracycline resistance in a strain of
Streptococcus lactis
caused this organism to display reduced acid production, salt tolerance, pyruvate synthesis, growth at alkaline pH, and a loss in ability to produce ammonia from arginine. α-Ketoglutaric and oxaloacetic acids were found to accumulate in the growth medium of resistant cells, in contrast to none in the medium of susceptible cells. No free arginine could be detected in the intracellular fraction of resistant cells, but arginine was present in the intracellular fraction of susceptible cells and decreased in concentration upon the addition of oxytetracycline to the growth medium. Depressed acid production in milk by the oxytetracycline resistant strain is evidently a consequence of the inability of this organism to metabolize arginine effectively.
Disinfection of Aerosolized Pathogenic Fungi on Laboratory Surfaces
Authors: Kruse Richard H. , Green Theron D. , Chambers Richard C. , Jones Marian W.
Published: December 2020

The effect of several fungicides on laboratory surfaces contaminated with the tissue phase of aerosolized
Blastomyces dermatitidis, Coccidioides immitis, Cryptococcus neoformans
, and
Histoplasma capsulatum
was ascertained. A statistical analysis of the data shows the correlation between fungi, surfaces, time, and concentration of disinfectant. All fungicides were effective at established times and concentrations, and the type of contaminated surface affected the fungicidal efficacy. By interpolating plotted graphs, laboratory personnel may determine, with a given fungicide, the concentration and time required to disinfect instruments, pipettes, gloves, bench tops, and floors contaminated with a tissue phase of pathogenic fungi.
Gas Exchange with Mass Cultures of Algae
Authors: Hannan P. J. , Patouillet Constance
Published: December 2020

Comparisons of oxygen production and carbon dioxide absorption by an algal gas exchanger were made over a 3-month period. The data do not represent a continuous test, but they do represent results obtained when identical light intensities, CO
2
supply rates, and dilution rates with fresh culture medium had been used for more than 1 day. Steady-state conditions were thus assured, and the agreement in the data was excellent. Under the same experimental conditions, the unit was operated continuously for a 5-day period, and the daily variability in this test was less than in the results obtained from month to month. The variation between the average O
2
production during the 5-day test and the average of the tests over a several-month period was less than 3%. It is concluded, therefore, that the reliability of the algae in producing oxygen is sufficient to warrant their use in either submarine or space ship use.
Effect of Carbohydrates in Phosphate Buffer on Germination of
Bacillus stearothermophilus
Spores
Authors: Fields M. L. , Finley N.
Published: December 2020

Among strains, and among spore suspensions of the same strain, different spore-germination responses were observed when spores were heated in monosaccharides, disaccharides, and polysaccharides in 0.0083
m
phosphate buffer (pH 7.1). It was hypothesized that these differences were due to rough and smooth variants in the spore population and to variation in the osmosensitivity of spores of variants within the population when subjected to a heat shock of 110 C.
Bacteriology of Spoilage of Fish Muscle
Authors: Lerke Peter , Adams Ralph , Farber Lionel
Published: December 2020

A sterile raw fish muscle press juice, diluted 1:4 with saline, has been prepared. This dilution greatly facilitated Seitz filtration and affected the spoilage properties of the medium only negligibly. At 5.5 C, the spoilage pattern of naturally contaminated diluted juice was almost identical to that of naturally contaminated fillets. This was shown by comparing the quantitative and qualitative aspects of the bacterial flora on the two substrates and by measuring the production of volatile reducing substances (VRS) and of trimethylamine (TMA). With the sterile raw muscle press juice, some preliminary data showed that individual members of the genera
Achromobacter
and
Pseudomonas
differ markedly in their spoilage capabilities: some grew but did not produce spoilage detectable either organoleptically or chemically; others gave rise to strong off odors and to high levels of VRS and TMA.
Viability of Selected Microorganisms in Hydrocarbon Fuels
Authors: Hedrick H. G. , Carroll M. T. , Owen H. P. , Pritchard D. J.
Published: December 2020

A laboratory study of the viability of selected microorganisms in a hydrocarbon fuel medium was carried out on 19 species of microorganisms, representative of the types found as natural contaminants in aircraft fuels. More species remained viable when inoculated in pure cultures than when inoculated in mixed (composite) cultures. Of the 19 species selected, 10 were still viable after 3 months and 5 were viable after 4 months in the pure culture inoculants. In the complete composite culture inoculant, the bacterial species which were viable at the end of 4 months were the same as those found in the pure culture inoculant. No fungi remained viable in the complete composite cultures after a 3-week period. The microorganisms which remain viable in a hydrocarbon fuel medium are considered indicative of a satisfactory inoculum to be used as a test culture in laboratory analysis of mechanical control techniques.
Oxytetracycline-Resistant Coliforms in Commercial Poultry Products
Authors: Corey R. Reece , Byrnes Joseph M.
Published: December 2020

The presence of oxytetracycline-resistant bacteria was investigated with commercially frozen chicken thighs and drumsticks. Bacterial flora were surveyed by means of total and coliform counts with Tryptone Glucose Extract Agar and Desoxycholate Agar, respectively. After counting, the Desoxycholate Agar plates were replicated on the same medium containing 25, 50, 75, and 100 ppm of oxytetracycline. Resistant colonies were found on all samples that were replicated. Of 2613 colonies isolated on Desoxycholate Agar, 47.8% grew in the presence of 25 ppm of oxytetracycline. From 50 to 100 ppm, the number of resistant isolates remained essentially the same, near 34%. Of 812 colonies of antibiotic-resistant bacteria identified with dulcitol-lactose-iron-agar, 82.5% were paracolons, 13.7% were pseudomonads, and 3.8% were
Escherichia
or
Aerobacter
. Bacteria resistant to oxytetracycline were shown to be present on commercially processed chicken. The origin of the resistance to oxytetracycline was not established; however, since the antibiotic was not used during processing, it appeared that these antibiotic-resistant bacteria arose in the intestines of the chickens as a result of feed which contained antibiotic. This is supported by a comparison with the antibiotic resistance of coliforms from chickens raised on feed both with and without oxytetracycline, for the percentages of resistant colonies are similar in both commercial chicken and chicken raised on feed containing the antibiotic.
New Bacterial Polysaccharide from
Arthrobacter
Authors: Cadmus M. C. , Gasdorf Helen , Lagoda A. A. , Anderson R. F. , Jackson R. W.
Published: December 2020

A bacterial strain (NRRL B-1973) isolated from soil at Guatemala City and tentatively identified as an
Arthrobacter
species produced a polysaccharide with unusual properties. Conditions were studied for the production of this microbial gum in shaken flasks and 20-liter fermentors. Suitable nutrients for optimal polysaccharide production included 3% glucose, 0.3% enzyme-hydrolyzed casein, magnesium sulfate, manganese sulfate, and potassium phosphate buffer (pH 7.0). Polysaccharide yields ranged from 40 to 45%, based on initial dextrose in the medium in 3- or 4-day fermentations. The gum was readily recovered from culture fluid by alcohol precipitation in the presence of an electrolyte. The
Arthrobacter
gum exhibited characteristics unique for a polyelectrolyte. Viscosity of solutions was not decreased by heating in the presence of salt, and the gum withstood a temperature of 121 C for 30 min. At polysaccharide levels above 0.75%, gels were formed when solutions were autoclaved with KCl. There was no significant change in viscosity over a pH range of 5.0 to 10.0.
Growth of Fungi in Sea Water Medium
Authors: Gray William D. , Pinto Patrick V. C. , Pathak S. G.
Published: December 2020

The effect of sea water on protein synthesis and growth of some species of Fungi Imperfecti was investigated. The dry weight of mycelia was greater from sea water medium than from distilled water medium in most instances; however, in a few there was a marked reduction in growth. The beneficial effect could not be ascribed to sodium choride or phosphate ion but may be due to the magnesium ion in sea water. This is indicated by the increase in mycelial yield and protein synthesis, even above that obtained with sea water, when magnesium ion was added to the medium. The reduction in yield and protein synthesis in some instances may be attributed to metal interactions; this possibility is being investigated further.
Dialysis Fermentor Systems for Concentrated Culture of Microorganisms
Authors: Gallup D. M. , Gerhardt Philipp
Published: December 2020

Cell-mass production of
Serratia marcescens
was studied in dialysis systems in which growth was managed in a fermentor remote from, but connected by conduits and pumps with, a nutrient reservoir. Dialysis was accomplished with membrane tubing in either the fermentor or the reservoir, or best with membrane sheet in a plate-and-frame dialyzer that was remote from but connected with both vessels. Growth trials with these systems demonstrated their ability to produce virtually unlimited population density in a liquid culture, viable counts in excess of 10
12
cells/ml and partial cell volume of 50% being attained. The system used for growth also may be used, after the growth cycle, to concentrate cells still further by osmotic dehydration with a hydrophilic colloid. The dialyzer-dialysis system that was evolved permits independent control of the component operations and is believed to be adaptable to any desired scale of size.
Rumen Bacterial and Protozoal Responses to Insecticide Substrates
Authors: Williams P. P. , Robbins J. D. , Gutierrez J. , Davis R. E.
Published: December 2020

Insecticides containing organophosphate, chlorinated hydrocarbon, and carbamate were tested with bovine ruminal ingesta fractions. Rumen bacteria exposed to insecticide levels of 0 to 500 ppm in rumen fluid for 4 hr were inoculated into rumen fluid-starch feed extract medium. No apparent significant bacterial count inhibitions were noted. Also, when insecticides were used as carbon sources at concentrations of 500 ppm in carbohydrate-limited media, no increases in bacterial counts were indicated. Warburg manometric data showed that paraffin oil-Triton X-155 preparations of dimethoate, Diazinon, lindane, Thiodan and Sevin stimulated gas production in holotrich protozoa.
Entodinium simplex
, an oligotrich, produced less gas with insecticide substrates per unit of dry weight than did an
Isotricha
sp. Rumen bacteria and plant debris fractions from ruminal ingesta provided with insecticides did not give increased manometric responses over the endogenous control vessels. Washed suspensions of
I. intestinalis
produced volatile fatty acids in excess of the endogenous suspensions when provided insecticide substrates. Thiodan dissimilation by
I. intestinalis
was followed colorimetrically with 15% loss in substrate in 1 hr of incubation at 39 C. Diazinon-
C
14
substrate uptake was demonstrated with suspensions of
E. simplex
and
I. intestinalis
. Rumen ciliates are suggested as a possible means for screening out useful insecticides susceptible to microbial dissimilation for use on forage and other cattle-feed crops.
Microbiological Production of Gibberellic Acid in Glucose Media
Authors: Sanchez-Marroquin A.
Published: December 2020

Gibberellic acid production from various substrates was studied in 43 strains of
Fusarium
, among which
F. moniliforme
strain IOC-3326 was selected as the best producer. Experiments were carried out in shaker flasks and pilot plant fermentors. The results indicate that the best substrate for gibberellic acid production with this strain is composed of the following: glucose, 20 g; corn steep liquor, 25 g; ammonium nitrate, 2.6 g; monopotassium phosphate, 0.5 g; potassium sulfate, 0.2 g; and water, 1000 ml. Glucose, ammonium nitrate, and corn steep liquor were found to be critical. With this medium, maximal yields of 1196 mg per liter in shaker flasks and 997 mg per liter in fermentors were produced.
Gnotobiotic Silage
Authors: Huhtanen C. N. , Pensack J. M.
Published: December 2020

Selected strains of lactic acid bacteria isolated from grass silage were found to flourish when inoculated into irradiation-sterilized forage under gnotobiotic conditions. The acid content and pH of these silages resembled naturally fermented silage. Inoculation of gnotobiotic silage with
Clostridium sporogenes
and
C. tyrobutyricum
failed to cause any noticeable deterioration of silage quality.
Gradient Plate Bioassay for Tyrothricin and its Application to Dentifrices
Authors: Curry Janet C.
Published: December 2020

A bioassay for tyrothricin, based on a procedure used by Szybalski in bacterial resistance studies, was developed. Replacement of the tube dilution assay with this procedure represented economy in time and equipment, with a resultant increase in productivity. The procedure involved preparation of special agar plates which provided graded concentrations of tyrothricin along a horizontal axis. A culture dish was inclined, and a base layer of agar, without antibiotic, was poured to cover the bottom of the dish and allowed to harden. A second layer of agar, containing 1 ppm of tyrothricin, was poured and allowed to harden with the dish in a level position. Diffusion of the antibiotic from the top layer into the bottom layer yielded a concentration gradient. A third thin layer of agar seeded with
Streptococcus faecalis
was poured on the surface. After incubation, a bacterial growth front, representing the minimal effective concentration (MEC), developed. The MEC is expressed as distance (in millimeters) from the edge of the plate. Unknowns were directly related to a standard preparation for calculation of tyrothricin concentration.
Effects of Protein, Lipids, and Surfactants on the Antimicrobial Activity of Synthetic Steroids
Authors: Smith Rodney F. , Shay Donald E. , Doorenbos Norman J.
Published: December 2020

Three 4-azacholestanes and two
A
-norcholestanes were inactivated by 10 and 20% bovine serum and by 1.0, 2.5, and 5.0% sheep blood. The five compounds exhibited hemolytic properties when tested with 2% sheep blood and 2% human blood. These cholestanes inhibited
Streptococcus pyogenes
and were completely inactivated by 0.1% lecithin. Tween 80 was comparable to lecithin in causing the inactivation of steroids; 1% polyethylene glycol-4000 was inert; 1% Tween 20 and 1.0% Span 20 caused the inactivation of 3β,4-dimethyl-4-aza-5α-cholestane (ND-307). The sodium salts of four fatty acids, oleate, stearate, deoxycholate, and lauryl sulfate (0.1 to 1.0 mg/ml), effectively interfered with the action of ND-307. The steroids appear to have some properties similar to those of antimicrobial surfactants of the cationic type but have certain distinct features.
Use-Dilution Test and Newcastle Disease Virus
Authors: Lorenz Douglas E. , Jann Gregory J.
Published: December 2020

The use-dilution test for evaluating the effectiveness of disinfectants against bacteria was modified to determine the effectiveness of disinfectants against a group of viruses. Modifications were kept to a minimum to retain the general principles of the test and thereby retain the test's familiarity among testing laboratory personnel. Modifications included the use of a standard allantoic fluid suspension of Newcastle disease virus instead of a standard bacterial culture. The only other modification was the inoculation of six embryonated chicken eggs (10 to 12 days old) with 0.1 ml of nutrient broth into which a carrier ring was transferred after a standard period in diluted disinfectant. The death or survival of 60 embryos, then, is the criterion by which a disinfectant can be judged effective at use-dilution. Experiments are described which establish the validity of the modified test procedure. The effectiveness of nine common disinfectants against Newcastle disease virus as judged by this test procedure is reported.
Penetration by Gases to Sterilize Interior Surfaces of Confined Spaces
Authors: Opfell John B. , Wang Yui-Loong , Louderback Allan L. , Miller Curtis E.
Published: December 2020

The rate of penetration of gaseous sterilizing agents into confined spaces can be predicted from physical and chemical considerations. The exposure times required to obtain sterilizing concentrations of ethylene oxide in several configurations of confined space were predicted by computation and illustrated by experiment. The results of the computations are presented graphically.
Calibration of a Modified Andersen Bacterial Aerosol Sampler
Authors: May K. R.
Published: December 2020

A study of the flow regime in the commercial Andersen sampler revealed defects in the sampling of the larger airborne particles. Satisfactory sampling was obtained by redesigning the hole pattern of the top stages and adding one more stage to extend the range of the instrument. A new, rational hole pattern is suggested for the lower stages. With both patterns a special colony-counting mask can be used to facilitate the assay. A calibration of the modified system is presented which enables particle size distribution curves to be drawn from the colony counts.
Occurrence of Coliforms, Fecal Coliforms, and Streptococci on Vegetation and Insects
Authors: Geldreich E. E. , Kenner B. A. , Kabler P. W.
Published: December 2020

This study considers the sanitary significance of coliforms, fecal coliforms, and streptococci isolated from 152 species of plants and 40 samples of insects. These specimens were collected from various ecological environments and grouped into several categories. Results indicate that typical coliforms of the warm-blooded animal gut contribute a relatively small percentage of the organisms associated with vegetation (14.1%) and insects, (14.9%). A total of 1,203 coliform strains from vegetation and 1,084 coliform strains from insects were classified as to IMViC type and fecal coliform. No type was predominant in either the vegetation or insect groupings. The biochemical results for 646 streptococci from vegetation and 226 cultures from insects were reported. The predominant group,
Streptococcus fecalis
, as defined by Sherman criteria, constituted a majority of all strains from vegetation and insects. The “Completed Coliform Test” is recommended for the examination of plant and insect specimens to eliminate the many anaerobic and aerobic sporeforming bacteria that frequently produce false positive reactions by the “Confirmed Test” procedure. These findings support the current interpretation of the significance of the fecal coliform test for stream investigations or for surface water quality evaluations.
Single-Dose Assay Technique for Variola Virus
Authors: Riley Jean M. , Orlando Michael D.
Published: December 2020

A biological assay for variola virus was needed that would (i) require a minimum of time and (ii) have acceptable precision. Preliminary titrations made in 11-day-old embryonated eggs and in suckling mice (6 to 24 hr of age) demonstrated a linear relationship between the concentration of variola virus injected and the mean reciprocal time to death (MTD) of both hosts. This linear response indicated that the injection of a single dose of virus suspension and the measurement of the MTD should result in an acceptable assay method. Seven replicate samples of liquid preparations (20% chorioallantoic membrane in Heart Infusion Broth) and the freeze-dried material obtained with these suspensions were assayed in triplicate for pock infectious units and for MTD. The variance of the pock counts was far greater than was expected from a Poisson distribution, and coefficients of variation ranged from 25 to 61%. Variances obtained with the single-dilution assay were all far below that expected from a Poisson distribution, and coefficients of variations ranged from 5.2 to 13.6%. The use of the MTD assay resulted in a saving of time, a saving in the number of hosts necessary per assay, and increased precision.
Staphylococci in Competition
Authors: Peterson A. C. , Black J. J. , Gunderson M. F.
Published: December 2020

Previous results showed definite repressive effects on the growth of staphylococci in mixed cultures due to the competitive growth of psychrophilic saprophytes. This study was continued, and the influence of other environmental factors, pH and salt, on the competition between staphylococci and saprophytes was investigated. Initial pH values varied from 5 to 9. At the extremes of the pH range, staphylococci failed to grow, while the saprophytes grew under all of the conditions tested. At pH 5, the growth curves for the saprophytes were markedly altered from those obtained at neutral pH. The lag phases were greatly lengthened at and below 20 C, but normal numbers of saprophytes were reached in the stationary phase. At pH 6 and 8, staphylococcal growth showed the same inhibition observed at pH 7, at and below 20 C; normal multiplication was observed above this temperature, but with accelerated death phases. Thus, pH did not primarily effect staphylococcal growth through its influence on saprophyte growth and competition, but rather directly affected the growth of
Staphylococcus
cultures. Salt concentrations from 3.5 to 9.5% were investigated for influence on staphylococcal growth in mixed populations. Above 3.5% salt, staphylococcal inhibition at and above 20 C was not as marked as in the controls, although normal numbers were never reached. The saprophytes were increasingly inhibited, and their lag phases materially lengthened as salt concentration was increased. Salt acted directly on the
Staphylococcus
population and also, by repressing saprophyte growth, decreased competition, which allowed the staphylococci to grow.
D-Arabitol Production by
Endomycopsis chodati
Authors: Hajny G. J.
Published: December 2020

Endomycopsis chodati
in an aerated fermentation produced
d
-arabitol in yields of 35 to 40% of the sugar supplied. Glucose, mannose, and sucrose were suitable substrates. A synthetic medium was developed for the fermentation that showed that nitrogen in the medium must be limiting to obtain high yields of arabitol. Excess phosphate also tended to lower arabitol yields, although the effect was not so great as with nitrogen. Pilot plant-size fermentations were made in which all the nutrients were supplied by blackstrap molasses and urea. Arabitol yields in these fermentations were about 40% of the sugar supplied.
Lack of Influence of Suspending Media on Heat Activation of
Bacillus subtilis
Spores and Absence of Deactivation
Authors: Busta F. F. , Ordal Z. John
Published: December 2020

Bacillus subtilis
strain 5230 endospores suspended in a variety of suspending media at a concentration of ca. 10
8
per ml were heated at 95 and 75 C. The effect of the heating at 75 C was measured by plate count, and was reported as the heat-activated decimal fraction of the total viable-spore population. Thermal inactivation at 95 C was influenced by the suspending medium. No effects on heat activation at 75 C were noted for suspending media containing glucose, xylose, ribose, NaCl, or sodium phosphate, nor was there any marked effect due to a change in pH from 5 to 8. The heat-activation response was retained during postheating storage at 5 C in water up to 215 days. Postheating storage in several suspending media for 7 days also indicated no deactivation.
Trypsinization of Animal Tissues for Cell Culture: Theoretical Considerations and Automatic Apparatus
Authors: Gori Gio B.
Published: December 2020

The theoretical background and the experimental feasibility of an automatic control for the continuous trypsinization process are discussed. An automatic apparatus is described with experimental evidence that the optimal mean residence time of monkey kidney cells in the trypsinization flask is between 5 and 8 min, in a volume of fluid approximately ten times that of the tissue processed. A temperature of 36 C and a pH of 7.8 provide optimal conditions for cell viability.
Some Factors Influencing the Efficiency of Production of Acetylmethylcarbinol by
Rhizopus nigricans
Authors: Fields M. L.
Published: December 2020

Incubation time had no effect on the efficiency ratio [dry weight-acetylmethylcarbinol (AMC)] during the incubation times tested. The mycelium was more efficient in synthetic media at pH 3 and 4 than at pH 5 and 6. Mycelium also produced AMC more efficiently in apple juice and in synthetic media containing yeast extract or vitamins, especially thiamine. KCl, MgSO
4
, and KH
2
PO
4
had significant suppressing effects on AMC production in a synthetic medium.
Effect of Sodium Alginate on
Staphylococcus aureus
During Mild Heating and Freezing
Authors: Scott Lelia G. , Strong Dorothy H.
Published: December 2020

The effects of sodium alginate on
Staphyiococcus aureus
196 exposed to mild heating or to freezing at -21 C were studied. The addition of sodium alginate to a diluent appeared to confer some protection of viable cells during mild heating. The effect of the presence of sodium alginate in the suspending media during freezing was less clear. There was a slight trend, not statistically significant, for greater reduction in numbers of viable cells at the low temperature when 4% alginate was present in phosphate buffer. Results indicated that the value of sodium alginate in controlling this food-poisoning microorganism in frozen food is questionable.
Mass Culture of a Slime Mold,
Physarum polycephalum
Authors: Brewer E. N. , Kuraishi S. , Garver J. C. , Strong F. M.
Published: December 2020

The slime mold,
Physarum polycephalum
, was cultivated in a soluble natural medium in shake flasks and in 30-liter and 50-gal conventional baffled fermentors. Yields of 6 to 10 g (dry weight) per liter were obtained in the large-scale fermentations. Because of the slow growth of the myxomycete, particular attention had to be paid to aseptic technique. The inability of this organism to withstand the normal degree of agitation employed with most aerobic fermentations made it difficult to obtain adequate aeration. Conditions for growth of the organism on a pilot-plant scale are presented.
Substitution of Manganese for Tomato Juice in the Cultivation of Lactic Acid Bacteria
Authors: Stamer J. R. , Albury Margaret N. , Pederson C. S.
Published: December 2020

Tomato juice was separated by chemical and physical methods into various active fractions, as measured by growth response and acid production by numerous lactic acid bacteria. Incineration of the treated extracts with little apparent loss in activity established the fact that the stimulatory component was of inorganic composition. Of the various cations tested, manganese was the only element that produced biological activity comparable to that of the original extract. Of the 71 strains of lactic acid bacteria tested, 63 strains showed a definite requirement for manganese or tomato juice.
Production of Penicillin Acylase
Authors: Szentirmai Attila
Published: December 2020

The production of penicillin acylase by
Escherichia coli
Ny.I/3-67 has been increased by phenylacetic acid and phenoxyacetic acid, which themselves strongly inhibit the function of this specific enzyme. Other carbonic acids also increased penicillin acylase production, but to a lesser degree; they also weakly inhibited enzyme function. The production of this enzyme was effectively repressed with metabolic carbohydrates and polyalcohols. Because enzyme production is dependent upon temperature, an increase in the temperature of incubation (above 31 C) decreased production of the enzyme, and increased the repressive effect of carbohydrates and polyalcohols.
Survival of
Shigella
in Sewage
Authors: Wang Wen Lan L. , Dunlop Stuart G. , Munson Polly S.
Published: December 2020

Glycerol (30%) inhibited or delayed the adsorption of
Shigella
bacteriophage on its host organism,
S. flexneri
II; glycerol also inhibited or delayed the burst of phage, whether or not adsorption was carried out in the presence of glycerol. Studies of the mechanisms of these effects showed that viscosity and osmotic shock probably were not responsible for either phenomenon. The inhibition of adsorption, however, was proportional to the concentration of glycerol, and appeared to be a function of the hydroxyl groups on the glycerol molecule. The inhibition of burst seemed to be related to the osmotic pressure outside the bacterial cells.
Survival of Microorganisms in a Simulated Martian Environment
Authors: Hagen C. A. , Hawrylewicz E. J. , Ehrlich R.
Published: December 2020

Survival of
Bacillus subtilis
var.
globigii
in a simulated Martian environment was demonstrated. Previous contact with the simulated Martian soil or atmosphere reduced germination or outgrowth of unheated spores, or both. Inoculation into simulated Martian soil and then flushing with a simulated Martian atmosphere were lethal to both vegetative cells and spores. After one diurnal temperature cycle (26 to -60 C), the majority of of cells present were spores. No further effect of the diurnal cycle on survival was noted in any of the experimental samples.
Effect of Bacterial Polysaccharide Accumulation on Infiltration of Water Through Sand
Authors: Mitchell R. , Nevo Z.
Published: December 2020

A study was carried out of the mechanisms of biological clogging of sand during prolonged percolation of water containing high levels of organic matter. It was found that polysaccharide-producing microorganisms predominated in clogged layers of sand. A positive correlation was observed between accumulation in the profile of polysaccharides and clogging of columns of sand in permeameters. The level of oxygen in the system appears to determine the equilibrium between production of clogging materials and their decomposition.
Comparison of Sterilizing Properties of Formaldehyde-Methanol Solutions With Formaldehyde-Water Solutions
Authors: Willard Myra , Alexander Alice
Published: December 2020

Sterilizing properties of formaldehyde in anhydrous methanol and formaldehyde in water were compared. Formaldehyde in methanol achieved sterilization in 24 hr. Formaldehyde in water was found to sterilize in shorter periods of time and to have a longer shelf life than formaldehyde in methanol.
Induction of Lambda-Bacteriophage in
Escherichia coli
as a Screening Test for Potential Antitumor Agents
Authors: Heinemann Bernard , Howard Alma J.
Published: December 2020

A simple, rapid, quantitative test procedure to measure induction of phage production in lysogenic
Escherichia coli
K-12 (λ) was described. This test was used in a study of 209 substances, including antibiotics, pyrimirines, purines, alkylating agents, thiols, amino acids, vitamins, and miscellaneous compounds. Minimal inducing concentrations for the 26 (12.5% of total tested) substances found to be effective inducing agents, as well as a listing of the inactive compounds, are presented. Since 21 of the 26 active agents reportedly have antineoplastic activity in rodent tumor systems, it was concluded that the induction test may provide a useful screen for the detection of potentially useful antitumor compounds.
Factors in the Testing and Application of Algicides
Authors: Fitzgerald George P.
Published: December 2020

A review is presented of some of the factors affecting the laboratory testing and practical applications of chemicals toxic to algae. The basic factor demonstrated is that the amount of chemical required to inhibit the growth of algae is dependent on the amount of algae present and not on the volume of water in which the algae are dispersed. It is shown how a chemical can be tested for algistatic or algicidal properties, thus enabling one to decide how best to apply a particular chemical. The selectivity of chemicals and the development of resistance in algae towards certain chemicals is demonstrated. Also, it is shown how certain algae can appear to be resistant to chemical treatments because of their growth habit or their production of extracellular products which affect the toxicity of added chemicals. With a better understanding of how various factors can influence the effectiveness of toxic chemicals, it is hoped that the selection of a chemical and method of application to a particular problem will be more successful.
Cotton Closure as an Aeration Barrier in Shaken Flask Fermentations
Authors: Schultz Jerome S.
Published: December 2020

Oxygen transfer through a cotton plug follows Fick's law of diffusion. The apparent diffusion constant decreases as the density of cotton packing is increased. Formulas are derived which relate oxygen transfer to cotton-plug dimensions. Calculations indicate that the dimensions of a cotton plug can affect both the maximal oxygen uptake rate and the gas composition inside a shaken flask. In some situations, as with large flasks, the cotton closure can become the limiting factor to aeration.
Occurrence of Coagulase-Positive Staphylococci in Cheddar Cheese
Authors: Donnelly C. B. , Black L. A. , Lewis K. H.
Published: December 2020

Samples (13) from several lots of cheddar cheese incriminated in staphylococcal food poisoning and 343 samples of cheddar cheese purchased over a 3-year period in retail markets were examined quantitatively for coagulase-positive staphylococci with the smear plate technique. Of the food-poisoning samples, 11 contained coagulase-positive staphylococci in numbers that ranged from 50 to several million per g. Of the 343 market cheese samples, 20% contained coagulase-positive staphylococci in concentrations ranging from less than 50 to more than 200,000 per g. The phage patterns of 64 of 89 cultures isolated from the food-poisoning samples placed them in the miscellaneous phage group (44A) or in phage group IV and the miscellaneous group (42D/44A); 14 had phage patterns that involved group III, the group with which food poisoning has usually been associated. In contrast, over 50% of 104 cultures from the market cheese, which were typed at 100 times the critical test dilution, had phage patterns that involved group III. Of nine selected cultures isolated from the food-poisoning cheese, three (all in phage group III) were positive for enterotoxin by intravenous injection test of cats.
Sequential Formation and Accumulation of Primary and Secondary Shunt Metabolic Products in
Claviceps purpurea
Authors: Taber W. A.
Published: December 2020

The fungus
Claviceps purpurea
was grown on a rich and a limited nutrient medium such that alkaloid was produced after 8 days on the former medium and after 3 days on the latter medium. Cultures grown on both were assayed for the primary shunt metabolic products, polyols, trehalose, lipids, ribonucleic acid, and polyphosphate, and the secondary metabolic product, ergot alkaloid. Although differing considerably in composition, the two media nevertheless allowed formation of both primary and secondary shunt products. In both instances, however, the secondary product, ergot alkaloid, did not form until formation and accumulation of the primary products had ceased and the mycelial content of these products was actually decreasing. In both instances, alkaloid formation took place after the total dry weight of the mycelium had begun to decrease but while the dry weight of the residual, or structural portion of the mycelium, was either constant or increasing. The dilution of labeling in mannitol isolated from mycelia grown on rich medium containing 1,6-C
14
-labeled mannitol was 2.2. Thus, about half of the mycelial mannitol was actually mannitol which had been taken up directly from the medium.
Liquid Nitrogen Freezing in Microbiological Assay Systems
Authors: Sokolski W. T. , Stapert E. M. , Ferrer E. B.
Published: December 2020

Suspensions of
Lactobacillus leichmannii
were stored in liquid nitrogen and were used as direct inocula in vitamin B
12
assays. Complete recovery of viable cells was obtained when the suspensions in basal B
12
medium were rapidly frozen by direct immersion into liquid nitrogen and rapidly thawed by agitating the suspensions in a water bath at 40 C. Greater than 90% destruction occurred when the suspensions were in saline. However, both suspensions were usable in the B
12
assay system. Assay results on a number of test materials indicated good correlation between freshly prepared suspensions and frozen suspensions in basal medium stored 3 months. Suspensions in saline stored for 1 year in liquid nitrogen showed no detectable difference from the first day after freezing. Suspensions frozen slowly at the rate of 1 degree per min from 4 to -40 C and subsequently immersed in liquid nitrogen had a longer lag period of growth and were not usable in the 18-hr assay incubation system. A major advantage of a stored inoculum for direct use in a microbiological assay is the reduced day-to-day variation in the inoculum.
Production of Fungal Mycelial Protein in Submerged Culture of Soybean Whey
Authors: Falanghe Helcio , Smith A. K. , Rackis J. J.
Published: December 2020

Various soybean whey media were tested as substrate for seven species of fungi in submerged culture. Very little mycelial growth was obtained with
Morchella hybrida, Collybia velutipes, Cantharellus cibarius
, and
Xylaria polymorpha. Agaricus campestris
failed to grow.
Tricholoma nudum
and
Boletus indecisus
showed the greatest rate of growth and production of mycelial protein and the best utilization of soybean whey solids, with much shorter incubation times compared with those of the other species.
T. nudum
developed as spheres having diameters of about 5 to 8 mm, instead of the usual slurry or yeastlike form, in the presence of added ammonium acetate.
B. indecisus
always developed as spheres. Mycelial yields and production of protein by
T. nudum
greatly decreased with the addition of more than 1% glucose to soybean whey, whereas with
B. indecisus
the yield of protein almost doubled when up to 3% glucose was added. The effect of minerals on mycelial growth was determined. With soybean whey concentrated to 50%, the rate of mycelial growth of
T. nudum
was nearly doubled, but protein content of mycelia was greatly reduced. Mycelial growth and yield of protein of
B. indecisus
grown in concentrated whey were increased greatly. About 4 to 6 g of mycelial protein per liter can be obtained from fermentation in soybean whey, depending upon the medium used. Utilization of soybean whey by fungal fermentation may have economic value in whey disposal and in the production of products of high protein content.
Production of Antiserum for Staphylococcal Enterotoxin
Authors: Casman E. P. , Bennett R. W.
Published: December 2020

Immunization of rabbits with approximately 95% pure enterotoxin B and approximately 20 and 50% pure enterotoxin A yielded specific antisera which required no and little absorption, respectively, when used in the slide double-diffusion test. Methods for purifying enterotoxin A and for the production and absorption of antisera are presented.
Production and Purification of Milligram Amounts of Foot-and-Mouth Disease Virus From Baby Hamster Kidney Cell Cultures
Authors: Polatnick Jerome , Bachrach Howard L.
Published: December 2020

A stable line of baby hamster kidney cells for use in the production of, and subsequent purification of, foot-and-mouth disease virus (FMDV) was grown in large quantities on the cylindrical surfaces of 2-liter Baxter bottles. The bottles, in round wire cages, were rotated on a three-tiered roller mill. The cells retained their rapid growth characteristics and susceptibility to FMDV in a tris(hydroxymethyl)aminomethane buffer-containing medium which was especially formulated for large-scale work. This medium, without being changed, sustained cell growth for 6 to 7 days to yield confluent layers containing 500 to 750 million cells per bottle. In small-scale virus-growth experiments, harvested fluids contained about 10
3.8
to 10
8.8
plaque-forming units (PFU) per ml. This corresponded to a yield of 30 to 50 PFU per cell. In production runs with 190 cultures, the infectious fluids usually contained 10
7.9
to 10
9.2
PFU per ml, and the mass of essentially pure virus obtained therefrom ranged from 7 to 17 mg concomitant with cumulative infectivity recoveries of about 20%.
Occurrence of Gram-Positive Organisms Possessing Characteristics Similar to Those of
Salmonella
and the Practical Problem of Rapid and Definitive
Salmonella
Identification
Authors: Silliker J. H. , Deibel R. H. , Chiu J. Y.
Published: December 2020

The occurrence and incidence of gram-positive organisms which possess some biochemical and serological characteristics in common with salmonellae are described. These organisms were encountered as contaminants in various food products as well as in feces. Their growth in various
Salmonella
enrichment media, typical
Salmonella
-like growth on differential selective media, biochemical similarities to
Salmonella
, and agglutination in
Salmonella
polyvalent O antiserum serve as a source of possible confusion in analyses for
Salmonella
. Although a definitive identification was not performed, preliminary results indicate that these bacteria closely resemble members of the genus
Brevibacterium
. No sanitary significance could be associated with these bacteria, because they were never found to coexist with
Salmonella
. The occurrence of these bacteria illustrates the pitfalls of a cursory examination for
Salmonella
. On the premise that ultimate identification of
Salmonella
rests upon serological procedures, a rapid and definitive identification of suspect
Salmonella
isolates is proposed, based upon reactions with polyvalent group O, group O, and Spicer-Edwards H antisera.
Preservation of T
2
Bacteriophage With Liquid Nitrogen
Authors: Meyle Janet S. , Kempf J. Emerson
Published: December 2020

There have been few reports on the preservation of viruses at the temperature of liquid nitrogen (-196 C). In this study, factors affecting the survival of phage were observed. Phage lysates in broth did not lose titer after a storage period of 4 weeks in liquid nitrogen. The rate of freezing was not critical, but freezing in nitrogen vapor was not satisfactory. When the virus was partially purified and suspended in buffered saline solution, it rapidly lost titer. Of seven protective agents recommended in the literature, only gum acacia seemed to demonstrate significant protection of purified virus against loss of viability. The temperature of thawing of phage suspended in broth did not affect its titer after freezing and storing in liquid nitrogen.
Rapid Differentiation Between
Nocardia
and
Streptomyces
by Paper Chromatography of Whole-Cell Hydrolysates
Authors: Becker B. , Lechevalier Mary P. , Gordon Ruth E. , Lechevalier H. A.
Published: December 2020

Whole-cell hydrolysates were prepared from 58 strains of nocardiae and streptomycetes. Strains morphologically intermediate between the two genera and morphological variants of the same strains were included. Paper chromatograms made from the whole-cell hydrolysates clearly demonstrated
meso
-diaminopimelic acid as a major constituent of cultures of
Nocardia
spp., and LL-diaminopimelic acid as a major constituent of cultures of
Streptomyces
spp. In cultures of ten strains of
N. madurae
and of three of
N. pelletieri, meso
-diaminopimelic acid predominated, thereby supporting the assignment of these species to the genus
Nocardia
.
Chemical Sensitization of
Clostridium botulinum
Spores to Radiation in Meat
Authors: Krabbenhoft K. L. , Corlett D. A. , Anderson A. W. , Elliker P. R.
Published: December 2020

Beef ground round inoculated with 1,000,000 spores of
Clostridium botulinum
33-A per gram and containing various additives was exposed to gamma radiation. Spores were inactivated in samples (irradiated at 2.0, 2.5, and 3.0 Mrad) which contained sodium nitrate (1,000 ppm) plus sodium chloride (2.5%). Similar results were obtained when sodium nitrite (200 ppm) was substituted for sodium nitrate, except that there was evidence of spore survival in 1 of 120 cans irradiated at 2.0 Mrad. Spore destruction was based upon the absence of spores and mouse-lethal toxin in meat subcultures made from cans incubated at 35 C for 120 days. Spores were not destroyed when exposed to 2.5 or 3.0 Mrad in the absence of sodium nitrate, sodium nitrite, or sodium chloride. Furthermore, the use of these chemicals individually, together with radiation, was ineffective. The additives alone in the absence of radiation also did not cause spore destruction. Radiation levels of 2.0, 2.5, and 3.0 Mrad, when used with sodium chloride at 1.5 or 2.0% and sodium nitrate at 500 ppm or sodium nitrite at 100 ppm, were ineffective.