bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of the Stereoisomers of Isoleucine by
Lactobacillus fermenti
Authors: Chibata Ichiro , Yamada Shigeki , Ito Hiroshi , Ishikawa Setsuko
Published: December 2020

The use of four stereoisomers of isoleucine by
Lactobacillus fermenti
strain 36 was studied in detail. All four isoleucine isomers were used for growth in the presence of vitamin B
6
compounds, but only
l
-isoleucine was active in the absence of these vitamins. Of the vitamin B
6
compounds, pyridoxal and pyridoxamine were equally more effective than pyridoxine for the utilization of these isomers. Lowering the initial
p
H, decreasing the amounts of leucine and valine, and adapting the organism to
d
-alloisoleucine medium accelerated the use of isoleucine isomers. Thus, the conditions were established under which respective isomers gave the same growth response, and these findings were applied to the separate microbiological assay of
l
-isoleucine and total isoleucine isomers.
Effect of Culture Conditions on the Production of
d
-Galactose Oxidase by
Dactylium dendroides
Authors: Markus Z. , Miller G. , Avigad G.
Published: December 2020

The effects on enzyme production of inoculum size and age, medium composition, and culture conditions were studied in shake flasks and in a pilot-plant fermentor. Using a medium consisting of glucose, yeast extract, and inorganic salts in deionized water, we found that the addition of Cu
++
was essential for the formation of active enzyme. Cultures grown in the absence of added copper produced an inactive enzyme protein which could be activated by 10
-3
M Cu
++
. Thiamine fulfilled all requirements for exogenous vitamins for growth and enzyme production. Glucose concentrations higher than 1% markedly suppressed enzyme formation. The mycelium inactivated the enzyme on prolonged incubation of the culture. Mycelial autolysates and sonic extracts were found to contain a thermostable and slowly dialyzable galactose oxidase-inactivating factor. The experiments suggest that this factor operates as a chelating agent which forms complexes with the copper of the enzyme. Copper ions (10
-3
M) prevented enzyme inactivation and restored activity to samples previously inactivated by this factor.
Bacterial Growth as a Practical Indicator of Extensive Biodegradability of Organic Compounds
Authors: Prochazka G. J. , Payne W. J.
Published: December 2020

The proportionality of growth, as indicated by turbidity of cultures of
Pseudomonas
C12B, to the initial concentration of sodium dodecyl sulfate, dodecanol, or a mixture of C
10
-C
20
secondary alcohol sulfates, each provided as sole carbon source in basal mineral salts medium, was demonstrated. Subsequently, the direct correlation of culture turbidity as a growth indicator and degradation of sodium dodecyl sulfate and the C
10
-C
20
compounds was established. Degradation of these detergents was measured by the rise in surface tension and the decrease in methylene blue values, respectively. Turbidimetry was found to be a poor indicator of degradation of dodecanol in the early hours of culture, however, and did not correlate over a significant range with degradation of substrate. Viable cell counts did parallel dodecanol degradation as measured by gas-liquid chromatography. The use of bacterial growth as a reliable, quantitative, and easily measured parameter indicating biodegradability was suggested for those organic compounds which can be shown to serve as a carbon source for a bacterium.
Steroid Lysis of Protoplasts and Effects of Stabilizers and Steroid Antagonists
Authors: Smith Rodney F. , Shay Donald E.
Published: December 2020

Six synthetic antimicrobial steroids were examined for indications of their mechanism of action. Dequadin acetate, cetyl pyridinium chloride (CPC), and sodium deoxycholate were studied for comparison. Aerated cells of
Sarcina lutea
were washed, suspended in 1.06 M sucrose, and converted to protoplasts with 20 μg/ml of lysozyme. Lysis was measured optically at 650 mμ as a decrease in optical density. Screening tests with 50 μg/ml of each compound showed five steroids and CPC to be lytic. Protoplasts were strongly protected from lysis by pretreatment with 0.001 to 0.004 M spermine tetrahydrochloride. Other polyamines, such as spermidine phosphate, were less protective, and putrescine was ineffective. Uranyl nitrate (5 × 10
-4
M) rapidly agglutinated protoplasts and protected them from rupture by the lytic agents. Similar studies with 0.001 to 0.004 M Mg
++
showed varying degrees of protection, which, in most cases, was only temporary. Steroidal lysis did not appear to be related to chelation, since ethylenediaminetetraacetate did not cause lysis alone and antagonized some lytic compounds. Lecithin, Tween 80, Tween 20, and Span 20 at 0.05% exhibited certain effects on protoplast stability. Span 20 strongly prevented lysis by steroids. Tween 20 alone quickly caused protoplast rupture. Lecithin and Tween 80, which also caused lysis alone, interfered with lytic steroids and CPC. The test compounds were both inhibitory and lethal to cells of
Sarcina lutea
. The results suggest that direct action on cell membranes may be chiefly responsible for the antimicrobial properties of the steroids.
Production of Calcium Gluconate by
Penicillium chrysogenum
in Submerged Culture
Authors: Ambekar G. R. , Thadani S. B. , Doctor V. M.
Published: December 2020

The waste mycelium of
Penicillium chrysogenum
HA-10 (obtained at the end of penicillin fermentation), or a 24-hr-old freshly grown vegetative inoculum of this organism, was found to utilize glucose for the production of calcium gluconate by submerged fermentation in shake flasks. After 72 to 96 hr of fermentation at 24 C, 90 to 95% of the reducing sugar from the 15% glucose medium was converted to calcium gluconate. Reuse of the mycelium for successive experiments reduced the fermentation period to 72 hr or less because of an enhancement of glucose utilization. Ten successive batches of 15% glucose medium were fermented by the reuse method. Fermentation media containing up to 30% glucose could be used, provided boric acid was added to prevent the precipitation of calcium gluconate formed. We found that 30% hydrol (a by-product of glucose manufacture containing 50 to 55% reducing sugar), when used in place of glucose in the fermentation medium, inhibited the rate of glucose utilization. However, this effect was partially reversed by pretreatment of hydrol with 2 to 4% activated charcoal before addition to the fermentation medium.
Occurrence of Dermatophytes in Fresh Bat Guano
Authors: Kajihiro Edwin S.
Published: December 2020

Evidence is presented in support of the hypothesis that fresh bat guano serves as a means of pathogenic fungi dissemination in caves. A total of 371 guano samples were collected from caves in southeastern New Mexico. Each sample was agitated in sterile saline and sand. The supernatant fluid was treated with an antibiotic and streaked on differential media. Cultures were incubated at 25 and 37 C and examined at intervals over a 4-week period. For animal inoculation, highly concentrated inoculum was injected intraperitoneally into white Swiss mice. Animals were sacrificed 4 weeks later, and portions of their lung, liver, and spleen were cultured on selective media, incubated at 25 C, and examined at intervals over a 4-week period.
Microsporum gypseum
was isolated at all 10 collecting stations with an incidence of 22.4%,
Trichophyton mentagrophytes
at 7 stations with an incidence of 5%,
T. rubrum
at 3 stations with an incidence of 3%, and
T. terrestre
at 1 station with an incidence of 0.5%. From a total of 60 pools of liver-spleen-lung suspensions, 6 pools yielded positive cultures of
Histoplasma capsulatum
and 1 pool yielded
T. mentagrophytes
. No significant difference was found among the different selective media with respect to recovery of dermatophytes. Among the human pathogenic fungi isolated were
Candida
sp.,
Cladosporium
sp.,
Coccidioides immitis, Cryptococcus neoformans, H. capsulatum, M. gypseum, T. mentagrophytes, T. rubrum, T. terrestre
, and
Sporotrichum
sp.
Organic Acid Production by Basidiomycetes
Authors: Takao Shoichi
Published: December 2020

Sixty-seven strains belonging to 47 species of Basidiomycetes were examined for their acid-producing abilities in glucose media, in both the presence and absence of CaCO
3
, in stationary and shake cultures. Some strains were found to produce large quantities of oxalic acid. The oxalic acid-producing strains could be separated into two groups. Strains of one group (mostly brown-rot fungi) were able to produce oxalic acid, regardless of whether CaCO
3
was present in the medium. Strains of the other group (mostly white-rot fungi) were characterized by their ability to produce oxalic acid only when CaCO
3
was added to the medium. With the latter group, shake-culturing was generally more effective than stationary culturing in respect to acid production. In the CaCO
3
-containing media,
Schizophyllum commune, Merulius tremellosus
, and
Porodisculus pendulus
were found to produce substantial amounts of L-malic acid as a main metabolic product, along with small quantities of oxalic and other acids in shake cultures. Especially,
S. commune
and
M. tremellosus
may be employed as malic acid-producing species.
Penicillin Acylase Activity of
Penicillium chrysogenum
Authors: Erickson R. C. , Bennett R. E.
Published: December 2020

The penicillin acylase activity of
Penicillium chrysogenum
was studied. Washed mycelial suspensions of a high penicillin-producing and a nonproducing strain were found to be similar in respect to relative acylase activity on benzylpenicillin, 2-pentenylpenicillin, heptylpenicillin, and phenoxymethylpenicillin. The relative rates for both strains, as determined by 6-aminopenicillanic acid formation, were approximately 1.0, 2.5, 3.5, and 6.0 on the penicillins in the order given. The high producing strain formed both 6-aminopenicillanic acid and “natural” penicillins in fermentations to which no side-chain precursor had been added. Therefore, its demonstrated ability to cleave the natural penicillins, 2-pentenylpenicillin and heptylpenicillin, suggests that at least some of the 6-aminopenicillanic acid produced during such fermentations arises from the hydrolysis of the natural penicillins. At
p
H 8.5, the mycelial acylase activity of the nonproducing strain was about three times that at
p
H 6.0; at 35 C, it was about 1.5 times as active as it was at 30 C. When tested on penicillin G or V, no differences in either total or specific penicillin acylase activity were observed among mycelia harvested from cultures of the nonproducer to which penicillin G, penicillin V, or no penicillin had been added. Acetone-dried mycelium from both strains displayed acylase activity, but considerably less than that shown by viable mycelium. Culture filtrates were essentially inactive, although a very low order of activity was detected when culture filtrate from the nonproducer was treated with acetone and the acetone-precipitated material was assayed in a minimal amount of buffer.
Microbiological Assay of Vitamin B
12
in the Presence of Tetracycline
Authors: Poonawalla F. M. , Iyengar M. R. S.
Published: December 2020

Treatment of a pharmaceutical preparation of vitamin B
12
and tetracycline with an ion-exchange resin by the batch method differentially adsorbed tetracycline, making possible a statistically reproducible microbiological assay of vitamin B
12
by the standard
Escherichia coli
plate method.
Factors Affecting the Antimicrobial Activity of Vitamin K
5
Authors: Merrifield Larry S. , Yang H. Y.
Published: December 2020

Pure cultures of
Escherichia coli, Bacillus subtilis, Proteus vulgaris, Staphylococcus aureus
, and
Pseudomonas fluorescens
were used in this investigation. The bactericidal concentrations of vitamin K
5
required for
E. coli, B. subtilis, P. vulgaris, S. aureus
, and
P. fluorescens
; the effect of an absence of oxygen; the effect of contact time with
E. coli
and
S. aureus
; and the effect of initial counts per milliliter of
E. coli
were studied. The bactericidal concentrations ranged from 60 ppm of K
5
for
S. aureus
to 220 ppm for
E. coli
, with an initial count of 160,000 to 200,000 cells per milliliter and a contact time of 12 hr in nutrient broth. The gram-positive bacteria tested were more susceptible to the antimicrobial activity of vitamin K
5
than the gram-negative bacteria. In the studies conducted under nitrogen atmosphere, the per cent inhibition showed an inverse relationship to the bactericidal concentrations required for complete inhibition in studies conducted under air atmosphere. This finding suggested that there might be different factors responsible for inhibition depending on the species of bacteria being tested, and it also might help explain the difference in concentrations necessary for inhibition. Cells of
E. coli
and
S. aureus
were not inhibited immediately on coming into contact with vitamin K
5
; 50% inhibition occurred after 25 and 32 min, respectively. A rapid inhibition rate was maintained until approximately 90% inhibition occurred, after whch a rapid decrease in the rate was noted.
Cellulase from
Ruminococcus albus
and Mixed Rumen Microorganisms
Authors: Leatherwood J. M.
Published: December 2020

Cellulase in the cultural filtrates of
Ruminococcus albus
and cellulase extracted from mixed rumen microorganisms were investigated with acid-swollen cellulose and carboxymethylcellulose as substrates. Maximal activity occurred at approximately
p
H 5.8 and 47 C. Apparent Michaelis constants (
K
m
) varied between 0.53 and 0.02% carboxymethylcellulose, depending on the level of activity and the method of assay.
R. albus
cellulase has a lower
K
m
value than the enzyme extracted from mixed rumen microorganisms. Antisera from rabbits immunized with a cellulase preparation from
R. albus
inhibited the cellulolytic activity of both systems. Based on the relative degree of inhibition, approximately 20% of the cellulase of the mixed rumen microorganisms was immunologically similar to
R. albus
cellulase. Ratios of activity in different assay techniques showed the two sources of activity to be similar in the mechanisms of degradation. However, glucose is the main product of cellulose degradation by mixed rumen microorganisms, and cellobiose is the product of degradation by
R. albus
.
Efficiency of Chlorine Dioxide as a Bactericide
Authors: Benarde Melvin A. , Israel Bernard M. , Olivieri Vincent P. , Granstrom Marvin L.
Published: December 2020

We found chlorine dioxide to be a more effective disinfectant than chlorine in sewage effluent at
p
H 8.5. Chlorine dioxide was also found to be a more stable bactericide in relation to
p
H in the range studied.
New Technique for Mass Assays of Physiological Characteristics of Unicellular Algae
Authors: Massey Richard L. , Mattoni Rudolf H. T.
Published: December 2020

An apparatus is described and illustrated which enables an investigator to inoculate simultaneously a large number of unicellular algal suspensions onto an agar surface. These inoculations may be repeated an indefinite number of times with a very small amount of inoculum. Good results have been obtained from tests in which large numbers of algae were placed onto selective media containing various amounts of many antibiotics, growth factors, sugars, etc.
Effects of Antimicrobial Agents on the Milky Disease Bacteria
Bacillus popilliae
and
Bacillus lentimorbus
Authors: Pridham T. G. , Hall H. H. , Jackson R. W.
Published: December 2020

The effects of antibiotics, sulfonamides, and other antimicrobial agents on vegetative cultures of five strains of milky disease bacteria were compared with those on
Bacillus subtilis
Cohn emend. Prazmowski,
Staphylococcus aureus
Rosenbach,
Sarcina lutea
Schroeter,
Escherichia coli
(Migula) Castellani and Chalmers,
Saccharomyces pastorianus
Hansen, and
Mucor ramannianus
Moel. Similar numbers of viable cells of each organism were exposed to the test materials by use of an antibiotic-sensitivity disc method adapted from techniques recommended by the Food and Drug Administration in the
Federal Register
. The results suggest that vancomycin or ristocetin, as well as a few other materials, might be useful in controlling contamination either during culture of the fastidious milky disease bacteria or in large populations of vegetative cells undergoing treatment to induce sporulation. Inhibitory concentrations of vancomycin and ristocetin in shaken-tube tests were much lower than expected in comparison with results of sensitivity-disc tests on the milky disease bacteria. Sublethal concentrations of the two antibiotics elicited some morphological change in the bacteria.
Storage Stability of
Clostridium botulinum
Toxin and Spores in Processed Cheese
Authors: Grecz Nicholas , Wagenaar R. O. , Dack G. M.
Published: December 2020

Growth initiated from detoxified spores of
Clostridium botulinum
62A resulted in toxin production of 50 to 10,000 mouse lethal doses (MLD) per gram of processed soft surface-ripened cheese. Regular assays during subsequent storage of toxic samples at 2 to 4 C revealed a characteristic two- to fivefold increase in toxin titer during the initial 1 week to 12 months of storage. Thereafter, the toxin titer remained constant for 2 to 4 years, after which the toxicity declined rapidly. At the end of 6 years of storage at 2 to 4 C, the samples still contained 20 to 5,000 MLD of toxin per gram, with the usual toxin level at 200 to 500 MLD. Toxic culture filtrates of
C. botulinum
incorporated into cheese and stored at 30 C for 60 days showed no decline in toxin in processed type I cheese, but toxin decreased slightly in processed type II and type III cheese. The surface flora of these cheeses did not attack but, on the contrary, protected
C. botulinum
toxin during storage at 30 C. Initial difficulties in recovering
C. botulinum
organisms from type I cheese were traced to growth inhibitory activity which could be removed by washing with distilled water in a centrifuge. Viable spores or vegetative cells could be recovered from all samples after 4 to 5 years of storage at 2 to 4 C. After 6 years, organisms were recovered from all except three samples of type I cheese. Two other samples showed a large decrease in viable organisms. In type III cheese, spores remained remarkably stable for 6 years at the level of the initial inoculum, i.e., approximately 10
5
spores per gram.
Effect of Vacuum Packaging on Growth of
Clostridium botulinum
and
Staphylococcus aureus
in Cured Meats
Authors: Christiansen Lee N. , Foster E. M.
Published: December 2020

Incrimination of vacuum-packaged smoked fish in outbreaks of botulism has raised questions about the safety of this process in comparison with other methods of packaging foods. It has been suggested, for example, that
Clostridium botulinum
may grow better in a vacuum-packaged product than in one that is packaged without vacuum. To evaluate this possibility, sliced bologna was inoculated with spores of
C. botulinum
type A, packaged in transparent plastic film with and without vacuum, and stored at temperatures within the growth range of the organism. There was no detectable difference in the rate of toxin development in the two types of packages. In contrast, vacuum packaging markedly inhibited the growth of
Staphylococcus aureus
on sliced ham. The results indicate that vacuum packaging has little if any effect on the ability of
C. botulinum
to grow in cured meats, but it may reduce the likelihood of staphylococcal food poisoning.
Predicting Production in Light-Limited Continuous Cultures of Algae
Authors: Eppley Richard W. , Dyer Denzel L.
Published: December 2020

Equations relating productivity, growth rate, cell concentration, and light absorption lead to the prediction that, when incident light is below saturating intensity, maximal productivity will occur at half the maximal growth rate. The freshwater alga
Chlorella pyrenoidosa
TX71105 and the marine alga
Dunaliella tertiolecta
were grown in a small continuous culture apparatus with turbidostatic control. With both cultures, the cell concentration showed a linear decrease with dilution rate. Productivity was maximal at about one-half the maximal dilution rate. Average mass per cell increased near the maximal dilution rate, causing some asymmetry in the productivity versus dilution rate curve. The chlorophyll content per unit mass decreased in this region, but the chlorophyll content per cell remained constant. Best production rate in a light-limited algal culture was obtained when the growth rate at very low cell concentration was determined in the apparatus and the dilution rate was set at one-half that value.
Action of Microorganisms on Bituminous Materials
Authors: Traxler R. W. , Proteau P. R. , Traxler R. N.
Published: December 2020

Visual effects of
Mycobacterium ranae
on a 135-penetration asphalt (asphalt 1A) are described, which show the texture and rheological characteristics of the asphalt to be modified by microbial action. A bentonite-asphalt emulsion system for asphalts 1A, 3A, and 6A was used to subject these materials to the degradative activity of
M. ranae
and
Nocardia coeliaca
for 4 months at 30 C.
N. coeliaca
caused 1.5-, 3.9-, and 6.8-fold increases in relative viscosity of asphalts 1A, 3A, and 6A, respectively. A similar susceptibility pattern for
M. ranae
was obtained on the same asphalts, but apparently this organism exerted even a greater effect on asphalt 6A since the viscosity of this residue was too hard to be determined satisfactorily. Comparison of these data with analyses of the three asphalts indicates that the organisms probably attack the resin components of the asphalts.
Injury and Growth of
Serratia marcescens
Studied in a Thermal Gradient Incubator
Authors: Dimmick R. L.
Published: December 2020

An incubator capable of producing a controlled thermal gradient of 0 to 40 C is described.
Serratia marcescens
was incubated in small tubes held in the gradient. When turbidity in the tubes was assayed and recorded by a semiautomatic photometer, growth-temperature patterns were obtained. The shape of these patterns was influenced by age of inoculum or by pretreatment of the culture. Cultures incubated for short times at 52 C, treated with hydrogen peroxide, or lyophilized before being incubated tended to grow at higher mean temperatures than untreated cultures. These findings illustrate the general utility of the instrument for studies of microbial growth.
Detection of Minimal Quantities of Foot-and-Mouth Disease Virus with Bovine Kidney Tissue Cultures
Authors: Gailiunas Peter
Published: December 2020

Minute quantities of foot-and-mouth disease virus (FMDV) were suspended in 500-, 1,000- and 2,000-ml volumes of virus growth medium and inoculated into primary bovine kidney cell cultures grown as monolayers in 5-liter Povitsky bottles. After 48 hr of incubation, the low concentrations of FMDV, containing from 10
-3
to 10
-1.7
plaque-forming units (PFU) per milliliter of inoculum, multiplied to approximately 10
6
PFU per milliliter of fluid. The presence of extracellular virus after multiplication was verified by assaying the fluid in 4-
oz
prescription-bottle cultures. Minimal quantities of FMDV were able to infect the cells and replicate despite the large volume of the suspending fluid. This technique may be applicable for the detection of trace amounts of FMDV in clinical samples and vaccines. Skin samples of unknown infectivity in limited tests gave identical positive or negative results in both steers and Povitsky cultures, but were consistently negative when tested in suckling mice and in prescription-bottle tissue cultures.
Microbiological Assay for Organic Compounds in Seawater
Authors: Litchfield Carol D. , Hood Donald W.
Published: December 2020

A method for the quantitative identification of organic compounds in seawater has been developed. When auxotrophic mutants of
Serratia marinorubra
were incubated at 21 to 24 C for 72 hr with constant agitation, standard bioassay reference curves were obtained. Sodium glycerophosphate (400 mg per liter), ammonium dibasic citrate (5 g per liter), and glycerol (25 ml per liter) supplied the needed nutrients for maximal growth with a limited concentration of the required metabolite. Data are presented for the microbiological assay for biotin in waters of the Gulf of Mexico and adjacent bays. The range of sensitivity for the biotin mutant A101V is 5 to 12 mμg per liter in seawater, with a growth response from 2 to 16 mμg per liter of seawater. The possible ecological and chemical significance of biotin occurrence in spring-summer off-shore water is discussed.
Continuous Cultivation of Virus in Cell Suspensions by Use of the Lysostat
Authors: Gori Gio B.
Published: December 2020

Theoretical considerations illustrate the feasibility and characteristics of continuous virus cultivation in cell suspensions Physical dimensions of the virus fermentor (lysostat) in relation to optimal yields can be predetermined. Poliovirus type 1 was grown on Hela S-3-1 (Saltzman) cells in a single-stage, percolator-type lysostat, with a yield of 421 TCID
50
per cell. Adenovirus type 14 was grown on KB (Eagle) cells in a two-stage lysostat with a yield of 116 TCID
50
per cell.
Production of 2,3-Butylene Glycol from Citrus Wastes. II. The
Bacillus polymyxa
Fermentation
Authors: Long Sterling K. , Patrick Roger
Published: December 2020

The conditions required for production of
levo
2,3-butylene glycol by
Bacillus polymyxa
from citrus molasses were studied. Starter cultures required acclimatization to the substrate prior to inoculation of the fermentation medium. Maximal production of butylene glycol with minimal residual sugar was obtained with a medium consisting of molasses, diluted to 20° Brix, and 0.4% urea. Optimal environmental conditions included aeration at 0.11 volumes of air per volume of medium per minute, maintenance of
p
H at 6.0 to 6.2, a fermentation temperature of 30 C, and a stirring rate of 420 rev/min. The concentration of butylene glycol obtained in the fermentation beer ranged from 2.3 to 4.4%. The optical rotation of the glycol ranged from [α]
D
23°
= -1.01° to -10.45°. The variation in rotation was probably due to the presence of contaminating substances in the distillate.
Microbiological Aspects in the Hydroxylation of Estrogens by
Fusarium moniliforme
Authors: Casas-Campillo C. , Bautista M.
Published: December 2020

A strain of
Fusarium moniliforme
(IH4), isolated from soil, showed outstanding enzymatic abilities to hydroxylate a number of estrogens. Estrone and estradiol were transformed into the 15α-hydroxy derivatives, and estradiol 3-methyl ether was transformed into the corresponding 6β-hydroxy derivative. Δ
6
-Estrone was not hydroxylated. The accumulation of 15α-hydroxyestrone was influenced by the nutritional conditions of the fungus. Maximal yield was obtained when the organism grew in Czapek solution supplemented with yeast extract, although good conversion was also found in a peptone-corn molasses medium. Substitution of NO
3
-N in Czapek medium with NH
4
-N, lactalbumin hydrolysate, Casitone, or Casamino Acids resulted in limited hydroxylation of estrone. A remarkable strain specificity was demonstrated in this conversion. Of 13 strains of
F. moniliforme
and
Gibberella fujikuroi
under investigation, only 2 strains (IH4 and ATCC 9851) accumulated substantial amounts of the 15α-hydroxylated product. However, marked quantitative variations were observed which are attributable to a different ability of the organisms to degrade the steroid nucleus. Biochemical instabilities were also found through the appearance of spontaneous variants lacking steroid-hydroxylating activity. Replacement culture studies revealed that 15α-hydroxylation of estrone was dependent on the supply of external phosphate; exogenous nitrogen or energy sources were not required. Most of the enzymatic activity was confined to the mycelia. Microconidia showed a very limited hydroxylating activity, even in the presence of supplements or energy sources.
Characteristics of Yeasts Isolated from Pacific Crab Meat
Authors: Eklund M. W. , Spinelli J. , Miyauchi D. , Groninger H.
Published: December 2020

A total of 202 cultures of yeasts were isolated and characterized from king crab and Dungeness crab meat. A yeastlike organism, resembling
Aureobasidium pullulans
, and 15 different species distributed among the genera
Rhodotorula, Cryptococcus, Torulopsis, Candida
, and
Trichosporon
were represented. Nine of the species grew at 5 C or lower. Although two of the species grew at 37 C, none of the isolates had the characteristics of pathogenic species. Members of the
Cryptococcus
and
Candida
failed to grow at 37 C. Furthermore, species of the former genus were not pathogenic to mice. The pigmentation of the
Rhodotorula
cultures decreased in intensity as the incubation temperature was decreased. Biochemical activities of the different species were studied by use of triglycerides, lecithin, and proteins (casein, gelatin, and crab-meat protein) as substrates. Eight of the species could attack triglycerides; eight, lecithin; five, gelatin; one, casein; and one, crab protein. An organism, tentatively identified as
Trichosporon
sp., was very active in attacking each of the substrates tested and grew well at 0.5 C.
Production of Alanine by
Fusarium moniliforme
Authors: Carito Sebastian L. , Pisano Michael A.
Published: December 2020

Fusarium moniliforme
grown in a chemically defined medium in submerged culture accumulated amino acids extracellularly. Alanine and glutamic acid were present in greatest amounts, with traces of glycine, lysine, threonine, and valine detectable. Increasing the glucose and urea concentrations of the medium increased yields of alanine. Further increases in alanine production occurred with elevated levels of mineral salts in the medium, whereas the addition of a vitamin mixture proved to be inhibitory. Chemical changes resulting from the growth of
F. moniliforme
in the final fermentation medium disclosed maximal alanine production, mycelial weight, and glucose consumption after 72 hr of incubation at 28.5 C. Total soluble nitrogen, by contrast, was minimal at the same time period. The
p
H remained in the alkaline range throughout the fermentation.
Bactericidal Properties of the Concentrated Artificial Kidney Bath Solution
Authors: Bower John D. , Belle C. H. , Hench M. E.
Published: December 2020

This study was undertaken to investigate the ability of a 30 times concentrated dialysate fluid to support or inhibit growth of bacteria, and to evaluate its shelf life. The solution was inoculated with the following organisms in the logarithmic-growth phase:
Escherichia coli
, coagulase-positive
Staphylococcus aureus
, enteric
Streptococcus
sp.,
Pseudomonas
sp.,
Klebsiella-Aerobacter
sp.,
Proteus
sp., and
Bacillus subtilis
. Inoculated concentrate held at 37 C showed an exponential decrease in organisms for all species except
B. subtilis
, with no organisms recoverable at 24 hr. To determine the effects of temperature, solution inoculated with
E. coli
and
S. aureus
was kept at 4 and 20 C. Lesser rates of bacterial decline were found at the lower temperatures, with some organisms surviving for 146 hr at 4 C. For the evaluation of shelf life, 2 liters of the solution was kept at room temperature in screw-cap bottles for 8 months; no bacterial growth occurred. The self-sterilizing property of this solution is important practically, since it removes another source of contamination from patients with reduced resistance to infection due to chronic renal disease or immunosuppressive therapy for renal homotransplantation.
Radiation Survival of Food Pathogens in Complex Media
Authors: Dyer John K. , Anderson A. W. , Dutiyabodhi Pisawat
Published: December 2020

When 15 bacterial species representing genera associated with food-borne diseases were irradiated individually, all except
Escherichia coli
and
Streptococcus faecalis
showed typical linear dose-survival curves in Hartsell's broth. The minimal lethal dose (MLD) for the organisms tested ranged from 3.0 × 10
5
to 6.0 × 10
5
rad.
Salmonella paratyphi
B,
S. wichita, S. typhi, E. coli
, and
S. faecalis
were found to be the least sensitive to radiation. In commercially canned crabmeat the survival curves of
S. typhi, S. paratyphi
B, and
S. wichita
exhibited to varying degrees an initial linear death decline with increasing radiation doses, followed by a distinct tailing effect caused by survival of low numbers at the higher doses. The above species of
Salmonella
were further individually subjected to γ-radiation in various dilutions of crabmeat. The “tailing effect” gradually disappeared, with the dose-survival curve tending to become linear as the concentration of the crabmeat decreased.
Microbiological Assay for Organic Compounds in Seawater. II
Authors: Litchfield Carol D. , Hood Donald W.
Published: December 2020

Biochemically deficient strains of
Serratia marinorubra
have been isolated with specific requirements for adenine, uracil, and threonine. Standard curves for dose to growth response have been obtained showing a linear sensitivity from 0.5 to 4.0 mg of adenine per liter of seawater, 0.1 to 2.0 mg of uracil per liter of seawater, and 0.5 to 10 mg of threonine per liter of seawater. These mutants have been used to test for the presence of their required metabolites in natural seawater samples from the Gulf of Mexico and adjacent bays. Of the three compounds under investigation, adenine was found in 10 samples, uracil in 2 samples, and threonine in none. The possible significance of these findings to the marine environment is discussed.
Quantitative Studies on Fabrics as Disseminators of Viruses
Authors: Dixon Glen J. , Sidwell Robert W. , Mcneil Ethel
Published: December 2020

The length of time that poliovirus could be recovered from wool gabardine and blanket, and from cotton sheeting, terry cloth, and knit jersey fabrics was determined under conditions of controlled temperature and humidity (25 C in 35 and 78% relative humidities). Three types of exposure of the fabrics to viruses were used: direct contact, aerosol, and virus-containing household dust having a high content of textile fibers. When held in 35% relative humidity, virus persisted for 20 weeks on wool fabrics, but only 1 to 4 weeks on cotton fabrics. At this relative humidity, virus titers on wool fabrics decreased rapidly to low but detectable levels which persisted for long periods of time, whereas in 78% relative humidity the decrease in virus titer was less rapid, but the period of viral persistence was shorter. Generally, virus titers on cotton fabrics held in both relative humidities decreased exponentially to an undetectable level. The method of exposure to virus had a definite effect on the duration of viral persistence on a given fabric. Virus contained in household dust was least stable.
Characteristics of the Vegetative Growth of
Bacillus popilliae
Authors: Rhodes R. A. , Sharpe E. S. , Hall H. H. , Jackson R. W.
Published: December 2020

Growth characteristics of the insect pathogen,
Bacillus popilliae
Dutky, were studied by propagation in shaken flasks and in 2-liter fermentors. Maximal populations between 5 × 10
8
and 2 × 10
9
viable cells per milliliter of culture medium routinely were obtained in incubation periods of 18 to 24 hr at 30 C in a medium composed of 1.5% yeast extract, 0.6% K
2
HPO
4
, and 0.2% glucose or trehalose. The carbohydrate required for growth in liquid media was fermented with the formation of 2 meq of acid per mmole of carbohydrate utilized; acid products ordinarily were not subsequently metabolized.
B. popilliae
is an aerobe, and the amount of growth obtained varied with aeration to an optimum at oxygen absorption rates of about 0.5. Maximal populations persist in a culture for periods of only 1 to 4 hr; cessation of growth was followed immediately by rapid death of cultures, so that less than 1% of the cells remained viable after 48 hr, and viability often was lost entirely by the end of 72 hr of incubation. No cytological evidence for spore formation was observed under any growth condition. Death was not associated with lysis of the cells, although extensive granulation ultimately occurred. Continuous neutralizaiton, augmented buffering, various techniques of dialysis, or slow feeding of the carbohydrate did not markedly alleviate the characteristic death of the cultures.
Effect of Different Commerical Agar Preparations on the Inhibitory Activities of Phenols
Authors: Sands J. G. , Bennett E. O.
Published: December 2020

The minimal inhibitory concentrations of 11 phenolic inhibitors were compared in five commercial agars and in nutrient broth. It was found that the brand of agar affected the end point obtained for a particular inhibitor, and that the degree of antagonism varied with each compound studied. The results indicate that there are at least two deleterious factors present in agar, one of which is water-soluble and one which is not. The major portion of the total antagonism was due to the water-soluble factor, which could be removed by washing the agar in warm distilled water prior to use in the test medium.
Microorganisms of the Upper Atmosphere
Authors: Fulton John D. , Mitchell Roland B.
Published: December 2020

The viable micropopulation found, at altitude over a city, in a land air mass was significantly higher than that found in a marine-influenced air mass. The percentage distribution of bacteria and fungi was approximately equal in both types of air masses. This indicates that, under the conditions of the experiment, the marine air mass was influenced by the land area over which it traveled during passage from its source to the sampling area. Activities taking place within the city significantly increased the micropopulation at altitude. This increase was quantitatively so small that it was not identifiable when the micropopulation moving into the city was high—as in a land air mass—but was recognizable when the micropopulation was low—as in a marine-influenced air mass. The modification of the micropopulation at altitude by temperature inversions was shown.
Role of Pectinolytic Yeasts in the Degradation of Mucilage Layer of
Coffea robusta
Cherries
Authors: Agate A. D. , Bhat J. V.
Published: December 2020

Pectinolytic yeasts,
Saccharomyces marxianus, S. bayanus, S. cerevisiae
var.
ellipsoideus
, and
Schizosaccharomyces
sp., predominated in the natural fermentation of coffee cherries of
Coffea robusta
variety grown in Chikmagalur district of Mysore State, India. These yeast species were found on the cherry surfaces, and evidence was adduced to show that the natural fermentation of coffee was the result of activity of microflora from the cherry surface itself rather than that of flora of air or water. Incorporation of pure cultures of
Saccharomyces
species was shown to aid the process when a mixture of all three species was used. An enzyme preparation from the
Saccharomyces
species was observed to hasten the mucilage-layer degradation.
Effect of γ-Irradiation on the Microflora of Freshwater Fish
Authors: Kazanas N. , Emerson J. A. , Seagran H. L. , Kempe L. L.
Published: December 2020

Microbial flora were compared in irradiated and nonirradiated yellow perch fillets. These studies included effects of irradiation on the total microbial population, the lag phase, and rate of growth in this freshwater fishery product. The work was conducted concurrently with sensory and chemical evaluation, and constituted part of an investigation designed to evaluate the effect of substerilization doses (0.3 and 0.6 Mrad) of Co
60
γ rays on the storage life of yellow perch fillets at 1.0 or 6.0 C. In five storage tests, total plate counts prior to irradiation did not exceed 8.7 × 10
5
per gram of sample; this count was reduced nearly 100% by irradiation with either 0.3 or 0.6 Mrad. Progressively lower maximal bacterial populations and lengthened lag phases were obtained as more radiation was used. The growth rate of the population did not appear to decrease significantly. Microbial data obtained in these studies confirmed the sensory and chemical studies, by indicating that irradiation can significantly extend the refrigerated shelf life of freshwater fish.
Rapid Fluorescein and Protein Assay Method for Fluorescent-Antibody Conjugates
Authors: Wells Arthur F. , Miller Curtis E. , Nadel Marvin K.
Published: December 2020

A method is presented for the rapid determination of the fluorescein content, protein content, and fluorescein-to-protein ratio for immune globulin conjugates with fluorescein isothiocyanate as the fluor. This method is based on the absorbance of the fluorescent antibody at those wavelengths primarily associated with the fluorescein and γ-globulin fractions, and permits these materials to be determined by a single nondestructive analytical procedure. A small sample of the fluorescent antibody, in many cases 0.1 ml or less, is adequate for the above determinations. A nomograph is presented which allows simultaneous determination of the materials from the observed absorbance at the two wavelengths. The method is sufficiently accurate for most applications of the fluorescent-antibody techniques. Although this procedure has been developed primarily for fluorescent-antibody conjugates prepared from rabbit γ-globulin, it can be used directly for antibodies prepared from other animals provided the γ-globulin is relatively free from albumin.
Comparison of Growth and Primary Shunt Product Formation by
Claviceps purpurea
Cultured on Succinic Acid and Glucose as Carbon Sources
Authors: Taber W. A. , Siepmann R.
Published: December 2020

Growth on a medium containing succinic acid as the sole carbon source produced 1 g (dry weight) of mycelium per liter of medium by 50 days of incubation, whereas 25 g of mycelium was produced in 10 days when glucose was also present in the medium. Primary shunt metabolism took place during growth on succinic acid in spite of the extremely slow growth. Mycelia grown on succinic acid contained a higher percentage of residual mycelium and phosphate, but a lower percentage of mannitol, carbohydrate, lipid, and water-soluble nitrogen, than mycelia grown on a mixture of glucose and succinic acid. Thus, although primary shunt metabolism is favored by rapid growth on a rich, balanced sugar medium, it can also take place during extremely restricted growth in a medium containing succinic acid as the sole carbon source.
Evaluation of Slit Sampler in Quantitative Studies of Bacterial Aerosols
Authors: Ehrlich Richard , Miller Sol , Idoine L. S.
Published: December 2020

Quantitative studies were conducted to evaluate the efficiency of the slit sampler in collecting airborne
Serratia marcescens
and
Bacillus subtilis
var.
niger
, and to compare it with the collecting efficiency of the all-glass impinger AGI-30. The slit sampler was approximately 50% less efficient than the AGI-30. This ratio remained the same whether liquid or dry cultures were disseminated when the sample was taken at 2 min of aerosol cloud life. At 30 min of aerosol cloud life, this ratio was approximately 30% for
B. subtilis
var.
niger. S. marcescens
recoveries by the slit sampler were, however, only 17% lower than the AGI-30 at 30 min of cloud age, indicating a possible interaction involving the more labile vegetative cells, aerosol age, and method of collection.
Stimulation of Proteinase Biosynthesis by Canavanine in
Streptococcus faecalis
var.
liquefaciens
Authors: Hammel Jay M. , Zimmerman Leonard N.
Published: December 2020

l
-Canavanine, an analogue of arginine, was found to stimulate the synthesis of an extracellular proteinase in
Streptococcus faecalis
var.
liquefaciens
. Cells grown in a synthetic medium containing 10
-4
m
arginine and 10
-4
m
canavanine produced almost twice as much proteinase as cells grown in 2 × 10
-3
m
arginine alone; total growth was the same in both media. Hydrolyzed proteinase samples were analyzed for arginine and canavanine by means of paper chromatography and electrophoresis. Arginine, but not canavanine, was detected in the purified enzyme sample.
Kinetics of Acetate Metabolism during Sludge Digestion
Authors: Smith Paul H. , Mah Robert A.
Published: December 2020

The quantitative contribution of acetic acid to methane production was studied by use of C
14
-labeled acetic acid. Samples of domestic sewage sludge were incubated anaerobically in Warburg vessels. The rate of methane production in the vessels was 0.033 μmoles per ml per min. C
14
-labeled acetic acid was added, and the turnover rate was calculated. The pool size of acetic acid in the sludge was 4.7 μmoles/ml. The turnover rate was 0.0052 min
-1
, giving a rate of formation of acetic acid of 0.024 μmoles per ml per min. Under these conditions, acetic acid would account for approximately 73% of the methane produced by the sludge. Acetic acid was found to exist primarily in an extracellular pool. The turnover rate of the extracellular pool was rapid, and it was concluded that most of the acetic acid must be metabolized to methane by a specialized microflora not involved in the formation of acetic acid.
Identification of Fluorescent-Antibody Labeled Group A Streptococci by Fluorometry
Authors: Hochberg Howard M. , Cooper James K. , Redys J. J. , Caceres Cesar A.
Published: December 2020

A quantitative system, amenable to automation, for determining the presence of group A streptococci in broth culture is described. After separation from the broth, the cells' protein coats are removed by digestion with 0.1% trypsin, and they are then stained with anti-A fluorescent antibody (FA). Excess FA is removed, and bound FA is put into solution by dissociation with demineralized distilled water. The amount of FA bound to the cells is quantitated by fluorometry of the solution. The level of nonspecific staining is measured by staining the cells with fluorescein-conjugated normal rabbit globulin absorbed with group A cells, dissociating, and quantifying, as above. The two quantities are subtracted to measure specific binding of FA to group A cells. A clinical trial showed 92% agreement with microscopists.
Effect of Available Water on Thermal Resistance of Three Nonsporeforming Species of
Bacteria
Authors: Calhoun C. L. , Frazier W. C.
Published: December 2020

Cells of
Escherichia coli, Pseudomonas fluorescens
, and
Staphylococcus aureus
, previously grown in Trypticase Soy Broth (TSB) at a high level of available moisture (
a
w
0.994) and at low levels produced by addition of NaCl or glucose, were heated in neutral phosphate buffer, and in this buffer adjusted to low levels of available moisture by means of NaCl or glucose. Glucose in the heating medium was more protective than NaCl for
E. coli
and
P. fluorescens
, but hastened the thermal destruction of
S. aureus
. Added protection was given
P. fluorescens
during heating in glucose-buffer solution at
a
w
0.97 by previous growth in TSB adjusted to that
a
w
value with glucose. Added protection was given
E. coli
during heating in NaCl-buffer solution at
a
w
0.98 by previous growth in TSB adjusted to that value with NaCl. With
S. aureus
, however, previous growth in TSB plus NaCl or glucose had little effect on heat resistance, but the solute in the heating medium had great influence, in that NaCl was very protective and glucose destructive. Opportunity may have been given during tempering of the cell suspension at 30 C in the heating medium prior to heating for the NaCl and glucose to diffuse into the staphylococcal cells.