bluuebunny/crossref_metadata_2025 huggingface dataset:
Sterilizing Effects of High-Intensity Airborne Sonic and Ultrasonic Waves
Authors: Pisano Michael A. , Boucher Raymond M. G. , Alcamo I. Edward
Published: December 2020

The lethal effects of high-intensity airborne sonic (9.9 kc/sec) and ultrasonic waves (30.4 kc/sec) on spores of
Bacillus subtilis
var.
niger
ATCC 9372 were determined. The spores, which were deposited on filter-paper strips, were exposed to sound waves for periods varying from 1 to 8 hr, at a temperature of 40 C and a relative humidity of 40%. Significant reductions in the viable counts of spores exposed to airborne sonic or ultrasonic irradiations were obtained. The antibacterial activity of airborne sound waves varied with the sound intensity level, the period of irradiation, and the distance of the sample from the sound source. At similar intensity levels, the amplitude of motion of the sound waves appeared to be a factor in acoustic sterilization.
Durhamycin, a Pentaene Antifungal Antibiotic from
Streptomyces durhamensis
sp. n
Authors: Gordon M. A. , Lapa E. W.
Published: December 2020

Durhamycin, derived from a previously undescribed soil isolate, is an apparently new antibiotic active against many of the fungi pathogenic for man and animals. Cultural and morphological characteristics and biochemical reactions of
Streptomyces durhamensis
are detailed. Methods of extraction of the antibiotic, physicochemical properties, antimicrobial spectrum, and results of mouse toxicity and protection tests are given.
Toxicity to Rats of Corn Invaded by
Chaetomium globosum
Authors: Christensen C. M. , Nelson G. H. , Mirocha C. J. , Bates Fern , Dorworth C. E.
Published: December 2020

Of 53 isolates of
Chaetomium globosum
Kunze isolated from corn, manufactured feed, and fiberboard, grown on autoclaved corn, and fed to rats, 25 were lethal within 4 to 6 days. Thirty-six single ascospore cultures of one isolate were uniformly lethal when similarly grown and fed to rats. Incubation of the fungus on corn for 6 to 8 weeks resulted in greater toxicity than shorter incubation times. Premortem symptoms indicated damage to the central nervous system of the affected animals, and postmortem lesions included hemoglobinuria, hemorrhagic enteritis, and subdural hemorrhaging. Corn invaded by
C. globosum
and toxic to rats had no detectable effects on swine when fed as their sole ration for 6 weeks, and appeared to be consumed with relish. The toxic substance was best obtained by defatting the fungus-invaded corn with petroleum ether (bp, 60 to 70 C), extraction with acetone, and further purification by elution from a silica gel column with acetone and 5% acetone in chloroform.
Long-Term Preservation of Fungus Cultures with Liquid Nitrogen Refrigeration
Authors: Hwang Shuh-Wei
Published: December 2020

A preservation technique was tested on 162 strains of culturally fastidious fungi sensitive to lyophilization, representing five classes. The results indicated that liquid nitrogen storage of frozen specimens may be used as an alternative to lyophilization for long-term preservation of stock cultures of fungi. The fungus was frozen in 10% (v/v) glycerol-water menstruum in heat-sealed ampoules. The cooling from ambient temperatures to -35 C was controlled at a rate of approximately 1 C per minute. Further cooling to the storage temperature of -165 to -196 C was uncontrolled and took place at an accelerated rate. Frozen ampoules were thawed in a water bath at 38 to 40 C. Viable and unmutated cultures were developed from reactivated specimens after storage for as long as 5 years.
Importance of the Isovalerate Carboxylation Pathway of Leucine Biosynthesis in the Rumen
Authors: Allison Milton J. , Bucklin Jerry A. , Robinson I. M.
Published: December 2020

Certain anaerobic ruminal bacteria synthesize the leucine carbon skeleton by use of a pathway different from that described in other microorganisms. These organisms carboxylate the intact carbon skeleton of isovalerate, synthesizing leucine-
2
-
C
14
from isovalerate-
1
-
C
14
. Strains of
Bacteroides ruminicola
and
Peptostreptococcus elsdenii
were like
Ruminococcus flavefaciens
in that they incorporated appreciable amounts of C
14
from isovalerate-
1
-
C
14
into cellular protein and in that the only labeled amino acid found was leucine. The specific activity of β-isopropylmalate dehydrogenase in extracts from
R. flavefaciens
and from the mixed bacterial population from the rumen was very low as compared with the specific activity of this enzyme in extracts from
Escherichia coli
. This suggests that the pathway of leucine biosynthesis that operates in many aerobic and facultative microorganisms is not the major pathway in rumen bacteria. This was supported by the finding that after fermentation of whole rumen contents with acetate-
2
-
C
14
, leucine from the bacterial cells had a specific activity lower than one would expect if acetate was incorporated directly into carbons 1 and 2 of leucine.
Aflatoxin Production and Degradation by
Aspergillus flavus
in 20-Liter Fermentors
Authors: Ciegler A. , Peterson R. E. , Lagoda A. A. , Hall H. H.
Published: December 2020

Yields of from 200 to 300 mg per liter of aflatoxins B
1
and G
1
were produced by two strains of
Aspergillus flavus
in 20-liter fermentors under proper conditions of inoculum (well-dispersed growth) and aeration (0.5 volume per volume per min of air, 300 rev/min, 30 psi back pressure, baffles). Peak yields were usually attained in 72 hr, after which the aflatoxin concentration declined rapidly. Degradation of aflatoxin depended primarily on mycelial lysis and high-aeration conditions. Cultures previously reported not to degrade aflatoxin could be induced to do so under these conditions. The percentage and rate of toxin degradation were independent of toxin concentration, and appeared to be nonenzymatic and nonspecific. Degradation simulating that occurring in the fermentor was achieved by reacting aflatoxin with peroxidized methyl esters of vegetable oil; initial degradation was rapid and appeared to involve a complex series of reactions.
Pure Culture Fermentation of Green Olives
Authors: Etchells J. L. , Borg A. F. , Kittel I. D. , Bell T. A. , Fleming H. P.
Published: December 2020

The method previously developed by us for the pure-culture fermentation of brined cucumbers and other vegetables has been applied successfully to Manzanillo variety olives. Field-run grade fruit was processed first by conventional procedures to remove most of the bitterness. Then the relative abilities of
Lactobacillus plantarum, L. brevis, Pediococcus cerevisiae
, and
Leuconostoc mesenteroides
to become established and produce acid in both heat-shocked (74 C for 3 min) and unheated olives, brined at 4.7 to 5.9% NaCl (w/v basis), were evaluated. The heat-shock treatment not only proved effective in ridding the fruit of naturally occurring, interfering, and competitive microbial groups prior to brining and inoculation, but also made the olives highly fermentable with respect to growth and acid production by the introduced culture, particularly
L. plantarum
. Of the four species used as inocula,
L. plantarum
was by far the most vigorous in fermentation ability. It consistently produced the highest levels of brine acidity (1.0 to 1.2% calculated as lactic acid) and the lowest
p
H values (3.8 to 3.9) during the fermentation of heat-shocked olives. Also,
L. plantarum
completely dominated fermentations when used in two-species (with
P. cerevisiae
) and three-species (with
P. cerevisiae
and
L. brevis
) combinations as inocula. In contrast, when
L. plantarum
was inoculated into the brines of unheated olives it failed to become properly established; the same was true for the other species tested, but even to a more pronounced degree.
L. brevis
was the only species used that failed to develop in brines of both heat-shocked and unheated olives. Modification of the curing brine by the addition of lactic acid at the outset, either with or without dextrose, led to a much earlier onset of fermentation with accompanying acid development, as compared to treatments with dextrose alone or nonadditive controls. Reasons for the marked improvement of the fermentability of Manzanillo olives receiving the prebrining heat-shock treatment are discussed.
Glucose Disappearance in Biological Treatment Systems
Authors: Jeris John S. , Cardenas Raul R.
Published: December 2020

Laboratory scale anaerobic and aerobic treatment units were conditioned with a daily slug-feed of glucose. After a period of acclimation and stabilization, glucose disappearance was monitored continuously after the slug feed. A continuous sampling apparatus is described. Mathematical analysis of the data indicate zero-order reactions for both biological treatment systems.
Virustat, a Device for Continuous Production of Viruses
Authors: Jacobson Homer , Jacobson Leslie S.
Published: December 2020

Methods for continuous production of viruses, and operation of the virustat, an apparatus in which such production was accomplished, were studied. Continuous production requires a separate continuous host growth chamber, such as the chemostat, and a multiunit virus growth chamber into which the virus-inoculated host cells are led. Successful continuous output of MS-2 and ϕX174 viruses, the latter in lysates, over periods of several days and at titers approximating those of batch lysates, was observed. Design problems include chamber sizes and flow rates, growth of resistant mutants within both virus and host growth chambers, clogging by lysis debris, and the phenomenon of self-inoculation. The latter represents virus growth in the first section of the chamber in excess of the washout rate, leading to lack of need for virus inoculation after an initial period. Use of the virustat for production and research purposes will require some attention to the formation of resistant bacterial colonies at pockets and surface sites of limited washout. With the virustat as a continuous virus production device, continuous purification methods are desirable. Research use of the virustat in continuous mutagenic population studies would require suppression of self-inoculation by use of many sections in the chamber, and improved servo control of host populations at low concentrations.
Effect of γ Irradiation on the Microflora of Freshwater Fish
Authors: Kazanas N.
Published: December 2020

Studies on the generic identification of bacteria isolated from nonirradiated and irradiated (0.3 and 0.6 Mrad) yellow perch fillets during the course of microbial spoilage have been conducted. After the enumeration and tabulation of macrocolonies on petri dish cultures obtained from fillets, isolates were examined and keyed out essentially according to modified morphological and biochemical protocols of Shewan. Identification was further confirmed through reference to
Bergey's Manual
. Data obtained from each isolate were coded and recorded on IBM cards to facilitate identification. Total aerobic microbial plate counts obtained from nonirradiated perch before storage ranged from 10
5
to 10
6
microorganisms per gram of fish. Organisms isolated from these fillets, in order of decreasing number, consisted of
Achromobacter, Alcaligenes, Pseudomonas, Brevibacterium, Micrococcus, Flavobacterium, Bacillus, Sarcina, Microbacterium, Corynebacterium
, yeasts,
Lactobacillus, Vibrio, Aeromonas
, and a few
Proteus
and
Escherichia
cells. During storage and as spoilage progressed, the flora shifted and the pseudomonads became predominant. Irradiation of fillets to 0.3 and 0.6 Mrad reduced the aforementioned flora to the
Achromobacter-Alcaligenes
group, which constituted the residual flora throughout fillet storage.
Safe Self-contained Carbon Dioxide-Hydrogen Anaerobic System
Authors: Brewer John H. , Allgeier Daniel L.
Published: December 2020

An anaerobic system is described which allows the microbiologist or hospital technician ease of operation not previously possible with other systems. Gas cylinders, vacuum pumps, valves, and gauges have been eliminated. A new anaerobic lid was developed that is fitted only with a snap-in rubber gasket, a double stainless-steel gauze flash arrestor, and a catalyst holder. The holder contains a palladium pellet catalyst which is active at room temperature and requires no heat for activation. This system was made specifically for use with a disposable hydrogen-carbon dioxide generator and a disposable methylene blue anaerobic indicator. In addition to ease of operation, this jar incorporates unique safety features which eliminate the possibility of a laboratory explosion. An oxygen-free atmosphere composed primarily of nitrogen and carbon dioxide was quickly achieved within the jar to insure maximal growth.
Clostridium tetani
in a Metropolitan Area: A Limited Survey Incorporating a Simplified in Vitro Identification Test
Authors: Byrd Thomas R. , Ley H. L.
Published: December 2020

In a limited survey, three toxigenic and one nontoxigenic strains of
Clostridium tetani
were isolated from 18 environmental samples from metropolitan Boston. No
C. tetani
was found in 100 samples of human feces, 20 samples of dog feces, and two samples of horse feces. A simple modification of the halo precipitin test was studied in conjunction with the mouse lethality test for tetanus toxigenicity and was found to be a useful, although not a wholly definitive, technique.
Effect of Antifungal Compounds on Aspergillosis in Hatching Chick Embryos
Authors: Huhtanen C. N. , Pensack J. M.
Published: December 2020

Aspergillosis was induced experimentally in hatching chick embryos by dipping them in water containing spores of
Aspergillus fumigatus
or
A. flavus
. The addition to the dip water of antifungal compounds prevented the development of this syndrome. Of the compounds studied, amphotericin B was most effective, followed by pimaricin and nystatin. Sorbic acid was without effect.
Viability of
Bacillus popilliae
after Lyophilization of Liquid Nitrogen Frozen Cells
Authors: Lingg A. J. , Mcmahon K. J. , Herzmann Cheryl
Published: December 2020

The per cent viability of
Bacillus popilliae
after lyophilization of liquid nitrogen frozen cells was determined. Lyophilization of 9- to 12-hr cells which had been suspended in 5% sodium glutamate plus 0.5% gum tragacanth, frozen in liquid nitrogen vapor, and dried 4 to 5 hr with the ampoules exposed to room temperature resulted in survival of 64.6% of the original cells. After storage of these lyophilized preparations for 6 months at room temperature, 10.5% of the original cells were still viable.
Influence of Culture Media on the Radiation Resistance of
Micrococcus radiodurans
Authors: Krabbenhoft K. L. , Anderson A. W. , Elliker P. R.
Published: December 2020

The addition of NZ-case (a tryptic digest of casein) to a growth medium (PC) consisting of tryptone, glucose, and yeast extract caused a significant decrease in γ radiation resistance of
Micrococcus radiodurans
. The level of radiation resistance was inversely related to the concentration of NZ-case. The
ld
50
for this organism was approximately 700 krad when grown in tryptone, glucose, yeast extract, and
dl
-methionine (TGYM) broth, but it was approximately one-half as resistant when grown in a PC medium containing 0.5% NZ-case (PCNZ). The resistance to ultraviolet light was also reduced. Cultures transferred from PCNZ to TGYM media regained the high level of resistance.
Production of Aflatoxin on Wheat and Oats: Measurement with a Recording Densitometer
Authors: Stubblefield R. D. , Shotwell O. L. , Hesseltine C. W. , Smith M. L. , Hall H. H.
Published: December 2020

A method has been developed for the production of aflatoxin by growing
Aspergillus flavus
NRRL 3145 on solid substrate wheat. Optimal yields of 900 μg of aflatoxin G
1
and 900 μg of aflatoxin B
1
per g of substrate were obtained in 4 to 5 days at 28 C. A study of aflatoxin production on hulls and groats of oats and on whole oats by
A. flavus
strains NRRL 2999, NRRL 3000, and NRRL 3145 revealed that aflatoxin was produced on all three substrates, although production was very slight on hulls. Strain NRRL 3145 grown on solid substrate groats produced the largest amounts of aflatoxin: 580 μg of B
1
and 450 μg of G
1
per g of substrate. A densitometric method for reading thin-layer chromatographic plates is described; this is more objective and more accurate than the visual methods previously used for the determination of all four aflatoxins.
Countercurrent Distribution Studies on Hamycin
Authors: Ganguli B. N. , Doctor V. M.
Published: December 2020

Hamycin, a polyene antifungal antibiotic, was isolated by use of countercurrent distribution. A pattern was obtained by plotting the absorption at 383 mμ of the contents of the various tubes against the tube numbers. The results indicated that the antibiotic contained three fractions, a major fraction (peak 2) comprising 48% of the total activity and two minor fractions (peak 1 and peak 3) comprising 3.62 and 11.32%, respectively, of the total activity. The solid material was isolated by pooling the contents of the tubes containing the major fraction, concentrating this in vacuo, and cooling. The antibiotic activities of the three peaks were evaluated by use of a cup-plate assay method with
Paecilomyces varioti
as test organism. All three components showed antibiotic activity; however, the preparation obtained from the major fraction showed approximately a 7-fold increase in antibiotic activity, a doubling of the
E
1cm
1%
value at 383 mμ, and approximately a 2.5-fold decrease in the amino acid content in comparison with the starting material. There was an apparent correlation obtained by plotting the curves of the absorption at 383 mμ of the different tubes comprising the major fraction and their biological activities.
Agar Concentration in Counting
Clostridium
Colonies
Authors: Eller Charles , Rogers Losson , Wynne E. Staten
Published: December 2020

Decreasing the agar concentration of a counting medium from the usual 1.5% resulted in larger colonies with less interference from gas in
Clostridium botulinum
115B and
C. sporogenes
PA 3679. Optimal agar concentration was 0.65% for
C. botulinum
with 24-hr incubation and 0.50% for
C. sporogenes
with 48-hr incubation. Lower concentrations yielded growth too diffuse for counting. Motility was considered the explanation for increased colony size in softer agar. The greater the degree of motility, the greater would be the diffusibility expected, and thus the higher the agar concentration required to insure discrete colonies. For quantitating motility, evaluations were made by use of microscopic examination of liquid cultures and rate of diffusion in a semisolid medium. With both criteria, the degree of motility of
C. botulinum
115B clearly exceeded that of
C. sporogenes
PA 3679. Small-colony variants of
C. botulinum
in 0.65% agar yielded only small colonies on subculture, with a corresponding decrease in degree of motility of the cells by both criteria. Colony size of the nonmotile
C. perfringens
ATCC 3624 was unaffected by lowered agar concentrations.
Coliform Behavior in Frozen Foods
Authors: Fishbein Morris , Surkiewicz Bernard F. , Brown Elijah F. , Oxley Harriet M. , Padron Adriano P. , Groomes Ralph J.
Published: December 2020

An assortment of 496 samples of frozen foods consisting of fish or marine products, variety types, and cream pie desserts were subjected to four parallel examinations for the recovery of
Escherichia coli
. The test procedures consisted of two low-temperature (35 C) and two high-temperature (44 C) presumptive tests, followed by an E C confirmatory test at 45.5 C. Of all the test methods examined, a single Lauryl Sulfate Tryptose (LST) presumptive test at 44 C gave best
E. coli
recovery (425). This recovery compared favorably with the lengthier Association of Official Analytical Chemists test with which only 420
E. coli
cells were recovered. The LST (44 C) test saves much time, since it renders a follow-up 48-hr confirmatory test unnecessary. Moreover, since 96% of all the
E. coli
are recovered within 24 hr by LST (44 C), it is essentially a 24-hr test. The results of this study also confirmed earlier findings, in that it is possible to describe a specific coliform bacteriological test method by simple reproducible productivity ratios.
E. coli
recovery dilution data and coliform group behavior were also examined.
Kinetics and Mechanism of Bacterial Disinfection by Chlorine Dioxide
Authors: Benarde Melvin A. , Snow W. Brewster , Olivieri Vincent P. , Davidson Burton
Published: December 2020

Survival data are presented for a fecal strain of
Escherichia coli
exposed to three concentrations of chlorine dioxide at four temperatures. Chick's first-order reaction equation is generalized to a pseudo
n
th-order model. Nonlinear least squares curve-fitting of the survival data to the
n
th order model was performed on an analogue computer. The data were observed to follow fractional order kinetics with respect to survival concentration, with an apparent activation energy of 12,000 cal/mole. Initial experiments support the thesis that the mechanism of chlorine dioxide kill occurs via disruption of protein synthesis.
Killing of Cells in Bacterial Colonies
Authors: Hunt Dale E. , Pittillo Robert F.
Published: December 2020

Bacterial colonies grown on membrane filters and transferred to plates of inhibitor-containing medium decrease in number of total viable colony-forming cells. The decrease in viable cell count occurs in direct proportion to the concentration of inhibitor present and the length of time the colonies are exposed to the inhibitor, suggesting that the kinetics of cell kill approximate a first-order chemical reaction.
Kinetics of the Thermal Inactivation of Type E
Clostridium botulinum
Toxin
Authors: Licciardello J. J. , Ribich C. A. , Nickerson J. T. R. , Goldblith S. A.
Published: December 2020

Rate of inactivation curves for the “free” toxin, prototoxin, or activated toxin in crude filtrates of
Clostridium botulinum
type E were nonlinear, consisting of a fast inactivating rate followed by a slow inactivating rate. Thermodynamic parameters were calculated over a temperature range of 125 to 145 F (51.7 to 62.8 C) for the two different inactivation rates. Energy of activation was low at the lower temperature and high at the higher temperature. The thermal requirement for inactivating similar concentrations of the “free” toxin, prototoxin, or activated toxin was considered to be the same.
Organic Acid Production by Basidiomycetes
Authors: Sasaki Yuji , Takao Shoichi
Published: December 2020

Cultural conditions were examined for the purpose of increasing yields of
l
-malic acid by the Basidiomycetes
Schizophyllum commune
and
Merulius tremellosus
, which have the ability to produce this acid as a main product in CaCO
3
-containing medium in shaken culture. The most favorable nitrogen sources selected were 0.3% (NH
4
)
2
SO
4
and 0.18% NH
4
Cl. Effective combinations of inorganic salts in the medium were 0.1% KH
2
PO
4
, 0.05% MgSO
4
·7H
2
O, and 0.05% KCl, and suitable concentrations of glucose were 5 to 10%. Several nonionic surface-active agents promoted the filamentous mycelial growth of these strains and increased acid production. In particular, Tween 80 in 0.3% concentration markedly stimulated malic acid production by
S. commune
, and yields greater than 50% based on available glucose, were obtained after 10 to 14 days. Acid production by
M. tremellosus
was stimulated most with 0.5% Carbowax 4000 (polyethylene glycol), and the resultant yields were more than 40%.
Characterization of Clostridia by Gas Chromatography
Authors: Moss C. Wayne , Lewis Vester J.
Published: December 2020

Fatty acids of 41 strains representing 13 species of
Clostridium
were extracted directly from whole cells and examined as methyl esters by gas-liquid chromatography. Both visual and quantitative comparisons of the resulting chromatograms for the presence and relative amounts of large major peaks allowed rapid differentiation of
C. perfringens, C. sporogenes
, and
C. bifermentans
from each other and from 10 other species. Each of the three former species possessed a different characteristic fatty acid methyl ester profile that was exhibited by all strains tested within the respective species. Culture age and growth media influenced the relative proportions of certain of the acids, but such differences did not limit species differentiation.
Absorption of Group A Streptococcus Anti-M Typing Sera with Broken Cells
Authors: Harrell William K. , Ashworth Helen
Published: December 2020

Group A streptococcus anti-M typing sera that cannot be made specific by absorption with whole streptococcus cells have been absorbed with the soluble and insoluble fractions of ruptured heterologous cells. The technique has been used successfully for preparing specific anti-M sera against eight serotypes of group A streptococcus. The method involves breakage of the absorbing cells in the presence of the antiserum, and incubation of the mixture at 37 C for 1 hr, followed by 3 to 5 days of incubation at 4 C. The procedure is useful for preparing specific antiserum from certain lots of unabsorbed antiserum that otherwise would have to be discarded because of undesirable cross-reactivity.
Aflatoxins: Production of the Toxins In Vitro in Relation to Temperature
Authors: Schroeder Harry W. , Hein Hugo
Published: December 2020

The production or accumulation of aflatoxins in vitro by four isolates on three substrates (acid-delinted cottonseed, shelled Spanish peanut, and rough rice) was studied in relation to temperature in the range of 10 to 40 C. Within the first 10 days after inoculation, the optimal temperature range for aflatoxin production was between 20 and 35 C. Only small amounts of the toxins were produced at 10 and 40 C. Within the optimal temperature range, the time required for toxin production and for significant accumulation decreased as the temperature increased. More aflatoxin G was produced or accumulated in relation to aflatoxin B at low temperatures (within the optimal range), and the G aflatoxins were metabolized more rapidly at the higher temperatures.
Gas Exchange of Algae
Authors: Ammann Elizabeth C. B. , Lynch Victoria H.
Published: December 2020

The oxygen production of a photosynthetic gas exchanger containing
Chlorella pyrenoidosa
(1% packed cell volume) was measured when various concentrations of carbon dioxide were present within the culture unit. The internal carbon dioxide concentrations were obtained by manipulating the entrance gas concentration and the flow rate. Carbon dioxide percentages were monitored by means of electrodes placed directly in the nutrient medium. The concentration of carbon dioxide in the nutrient medium which produced maximal photosynthesis was in the range of 1.5 to 2.5% by volume. Results were unaffected by either the level of carbon dioxide in the entrance gas or the rate of gas flow. Entrance gases containing 2% carbon dioxide flowing at 320 ml/min, 3% carbon dioxide at 135 ml/min, and 4% carbon dioxide at 55 ml/min yielded optimal carbon dioxide concentrations in the particular unit studied. By using carbon dioxide electrodes implanted directly in the gas exchanger to optimize the carbon dioxide concentration throughout the culture medium, it should be possible to design more efficient large-scale units.
Influence of Cations on Spheroplasts of Marine Bacteria Functioning as Osmometers
Authors: Rhodes Martha E. , Payne W. J.
Published: December 2020

Penetration of substrates into marine bacteria as influenced by cations has been demonstrated by the effects of increased osmotic pressure in spheroplasts of these cells. Spheroplasts of
Pseudomonas natriegens
, stabilized with lactose, underwent a metabolic swelling in the presence of a substrate to which they had been induced. Maximal and persistent swelling was achieved only by addition of catabolizable substrate and both Na
+
and K
+
. Addition, along with substrate, of Na
+
alone or K
+
alone did not stimulate swelling; no metabolic swelling occurred in the presence of a sugar to which the cells had not been induced. Confirmation of rapid uptake by induced cells of the inducer sugar,
l
-arabinose, but not the
d
-isomer, was obtained with
14
C-labeled substrate. Addition of NaN
3
completely inhibited swelling, and 2, 4-dinitrophenol and ouabain each suppressed it by 50%, indicating requirement for energy metabolism and involvement of an adenosine triphosphatase in the penetration phenomena of these cells.
Metabolism of Peptides by Rumen Microorganisms
Authors: Wright D. E.
Published: December 2020

Rumen microorganisms utilize tryptic peptides from
Chlorella
protein, forming carbon dioxide, volatile fatty acids, and bacterial protein. Peptide carbon is more efficiently converted into bacterial protein than is amino acid carbon. A progressive degradation of the peptides was demonstrated by use of columns of Sephadex G-25.
Pathways of Glucose Metabolism by Rough and Smooth Variants of
Bacillus stearothermophilus
Authors: Hill W. M. , Fields M. L. , Tweedy B. G.
Published: December 2020

The radiorespirometric method was used to study the pathways of glucose metabolism in the rough and smooth variants of
Bacillus stearothermophilus
NCA 1518. The Embden-Meyerhof (EM) pathway was more active in the smooth variant than in the rough variant. The participation of the hexose monophosphate shunt (HMP) and EM pathways in the smooth variant was calculated as 4.2 and 95.8%, respectively. The rough variant utilized glucose via the EM pathway exclusively or in combination with a pathway other than the HMP pathway. The estimated efficiency of the tricarboxylic acid system in the rough and smooth variants was 81.3 and 4.9%, respectively.
Decarboxylation of α-Keto Acids by
Streptococcus lactis
var.
maltigenes
Authors: Tucker J. S. , Morgan M. E.
Published: December 2020

Decarboxylation rates for a series of C-3 to C-6 α-keto acids were determined in the presence of resting cells and cell-free extracts of
Streptococcus lactis
var.
maltigenes
. The C-5 and C-6 acids branched at the penultimate carbon atom were converted most rapidly to the respective aldehydes in the manner described for α-carboxylases. Pyruvate and α-ketobutyrate did not behave as α-carboxylase substrates, in that O
2
was absorbed when they were reacted with resting cells. The same effect with pyruvate was noted in a nonmalty
S. lactis
, accounting for CO
2
produced by some “homofermentative” streptococci. Mixed substrate reactions indicated that the same enzyme was responsible for decarboxylation of α-ketoisocaproate and α-ketoisovalerate, but it appeared unlikely that this enzyme was responsible for the decarboxylation of pyruvate. Ultrasonic disruption of cells of the malty culture resulted in an extract inactive for decarboxylation of pyruvate in the absence of ferricyanide. Dialyzed cell-free extracts were inactive against all keto acids and could not be reactivated.
Antifungal Activity of Isothiocyanates and Related Compounds
Authors: Drobnica Ľ. , Zemanová M. , Nemec P. , Antoš K. , Kristián P. , Štullerová A. , Knoppová V. , Nemec P.
Published: December 2020

Data are presented concerning the antifungal activity of 11 natural isothiocyanates and 27 synthetized analogues in
Aspergillus niger, Penicillium cyclopium
, and
Rhizopus oryzae
, as well as in 13 additional saprophytic and parasitic fungi. A remarkable antifungal activity was observed in some analogues of benzylisothiocyanate and β-phenylethylisothiocyanate. The latter-mentioned compounds have not been described previously. In the group of benzylisothiocyanates, a correlation, which was inversely proportional, was detected between
ed
100
values for
A. niger
and
R. oryzae
and the corresponding molar solubilities of compounds in water. In contradistinction, no relationship was observed between antifungal activity and chemical reactivity of investigated derivatives.
Resistance of
Bacillus subtilis
var.
niger
Spores Occluded in Water-insoluble Crystals to Three Sterilization Agents
Authors: Doyle John E. , Ernst Robert R.
Published: December 2020

The resistance to destruction of spores of
Bacillus subtilis
var.
niger
occluded in crystals of calcium carbonate and exposed to ethylene oxide and moist and dry heat was determined and compared with the destruction of unoccluded spores. Occluded spores could not be inactivated with ethylene oxide. Resistance to inactivation was approximately 900 and 9 times higher for occluded than for unoccluded spores subjected to moist and dry heat, respectively, at 121 C. The protective effect may be due either to the unavailability of oxygen for destruction by oxidation or to inhibition of the loss of essential cell constituents by vaporization. Evidence also implicates the crystal structure as a thermal conductivity barrier. Occluded spores retained viability over a 3-year period compared with unoccluded spores which decreased over 90% during this period. Occluded spores in insoluble materials are seldom encountered in the technology of sterilization, but could be the most critical factor in the sterilization of interplanetary vehicles. Entrapped spores in insoluble materials are usually difficult to detect, and are very stable as well as extremely resistant to destruction by heat and ethylene oxide.
Elution of Loosely Bound Acid Phosphatase from
Staphylococcus aureus
Authors: Malveaux F. J. , Clemente C. L. San
Published: December 2020

Strains of
Staphylococcus aureus
from the International-Blair and the Seto-Wilson series of phage propagating strains were examined for acid phosphatase activity. This enzyme was found to occur in varying amounts in three different fractions: free (6 to 60%), loosely bound (25 to 82%), and firmly bound (0 to 46%). Propagating strain 3A, because of its high activity, was chosen for further study. The rate of enzyme production paralleled cell growth in Trypticase Soy Broth, but followed a biphasic pattern in a semisynthetic casein acid-hydrolysate medium with glyceryl phosphate. Maximal elution of acid phosphatase in the loosely bound fraction, presumably from the surface of cells, occurred in the alkaline
p
H range. From log-phase cells, elution was maximally effected with buffered 1.0 M KCl (
p
H 7.5), but stationary-phase cells required twice the concentration of KCl.
Effect of High Oxygen Concentration on Virulence of
Staphylococcus aureus
Authors: Schmidt Jerome P. , Ball Robert J.
Published: December 2020

Cultures of
Staphylococcus aureus
were agitated and treated with oxygen or air for a period of 29 days. At intervals of 1, 3, 9, 15, and 29 days, samples of washed cells were tested for coagulase activity and for abscess-producing ability. It was found that aeration with agitation initially increased abscess formation and that the increase was of the same magnitude for oxygen and air. Continued treatment beyond 1 day resulted in a progressive decrease in this activity which was more pronounced in the oxygenated cultures. Throughout the treatment, the bound coagulase activity remained constant. Thus, there appeared to be no quantitative relationship of coagulase titer with virulence as expressed by lesion formation.
Effect of Various Essential Oils Isolated from Douglas Fir Needles upon Sheep and Deer Rumen Microbial Activity
Authors: Oh Hi Kon , Sakai T. , Jones M. B. , Longhurst W. M.
Published: December 2020

The effects of essential oils isolated from Douglas fir needles on sheep and deer rumen microbial activity were tested by use of an anaerobic manometric technique. Rumen microorganisms were obtained from a sheep which had been fed mainly on alfalfa hay and dried range grass. One deer used in this study had access to Douglas fir trees the year around, whereas the other deer had no access to Douglas fir. All of the monoterpene hydrocarbons isolated from Douglas fir needles—α-pinene, β-pinene, limonene, myrcene, camphene, Δ
3
-carene, and terpinolene—promoted only slightly or had no effect on deer rumen microbial activity, whereas all of them promoted activity in sheep rumen microbes, except Δ
3
-carene and terpinolene, which inhibited activity. Of the oxygenated monoterpenes, all monoterpene alcohols—α-terpineol, terpinen-4-ol, linalool, citronellol, and fenchyl alcohol—strongly inhibited the rumen microbial activity of both sheep and deer. Monoterpene esters (bornyl acetate) produced mild inhibition for both sheep and deer microbes, and citronellyl acetate inhibited rumen microbial activity in sheep, whereas it promoted activity in both deer. Monoterpene aldehyde (citronellal) inhibited the activity of rumen microbes from both sheep and deer having no access to Douglas fir from the Hopland Field Station, whereas they produced no effect upon the deer having access to Douglas fir from the Masonite forest. Rumen microbial activity for sheep and deer was promoted slightly with aliphatic ester (ethyl-
n
-caproate). There was a marked difference between sheep and deer rumen microbes as affected by addition of the various essential oils. The monoterpene hydrocarbons promoted activity more on sheep rumen microbes than on deer, and the monoterpene alcohols inhibited sheep rumen microbial activity more than that of deer. Furthermore, the deer rumen microbes from Hopland Field Station were affected more than the deer from Masonite forest.
Enterotoxin B: Serological Assay in Cultures by Passive Hemagglutination
Authors: Johnson H. M. , Hall H. E. , Simon M.
Published: December 2020

Bis-diazotized benzidine hemagglutination with Formalinized sheep erythrocytes was adapted to the rapid and specific detection of enterotoxin B in staphylococcal culture fluids. There was complete agreement between hemagglutination inhibition (HI) and gel diffusion in detecting 8 enterotoxin B-positive cultures from a total of 68 staphylococcal cultures tested. The sensitivity of HI equals or exceeds that of gel diffusion. Also, results can be obtained in several hours, even with extremely low concentrations of enterotoxin, whereas it may require 24 hr to 1 week to obtain comparable results with gel diffusion. Problems associated with the presence of potent hemagglutinins for sheep erythrocytes in several staphylococcal culture fluids are discussed.
Antibacterial Action of Essential Oils of
Artemisia
as an Ecological Factor
Authors: Nagy Julius G. , Tengerdy Robert P.
Published: December 2020

Bacterial response to increasing amounts of the volatile oils varies significantly according to species of bacteria tested. Among the four species examined,
Escherichia coli
was the most resistant to the oils, followed by
Neisseria sicca, Bacillus subtilis
, and
Staphylococcus aureus
. The oils of
Artemisia tridentata
seem to have the same degree of antibacterial action as oils obtained from
A. nova
.
Effect of Processing on the Microflora of Norwegian Seaweed Meal, with Observations on
Sporendonema minutum
(Høye) Frank and Hess
Authors: Sieburth John McN. , Jensen Arne
Published: December 2020

Meal from the brown seaweed
Ascophyllum nodosum
(L.) Le Jol. is mainly used as an animal feed supplement. Since moist weed often develops a marked mold growth and since little was known about the microflora of seaweed meal, a cultural procedure was developed to enumerate the populations of bacteria, yeasts, and molds of seaweed meals manufactured by different drying processes. The microflora could be supported by a variety of media varying in levels of nutrition and in the source and concentration of salts. Fresh weed contained less than 10
3
bacteria and less than 10
2
yeasts and molds per g (dry weight). The type and extent of microbial populations in seaweed meal appeared to be dependent upon the method of seaweed drying. Rotary drum-drying at temperatures decreasing from 800 to 80 C maintained or reduced the microbial populations to 10
3
organisms per g (dry weight). Although meals with high nutritional quality can be obtained with warm air- or rock-dried weed, these conditions can also permit bacterial and mold development. Extended rock-drying in variable weather conditions and prolonged storage of moist weed, both of which decrease the nutritional quality, also lead to high bacterial numbers and to a marked development of the halophilic brown mold
Sporendonema minutum
which attained populations of 10
8
viable spores per g of dried weed. A poultry diet containing 5% badly molded weed had no apparent toxic or growth-depressing effect when fed to chicks.
Reproducibility of Staphylococcal Bacteriophage Types by Use of Different Concentrations of Bacteriophage
Authors: Degré Miklos
Published: December 2020

A comparative investigation was carried out on the reproducibility of staphylococcal bacteriophage types at 100 routine test dilution (RTD) and at the conventional concentrations, RTD and 1,000 RTD. The comparison includes multiple typing of laboratory strains and duplicate isolates from hospital patients. No significant difference was found in the reproducibility of the types at the different concentrations. A single concentration corresponding to 100 RTD is recommended for routine use in phage typing as a possible substitute for typing with two different concentrations.
Stability of Rubella Complement-fixing Antigens
Authors: Schmidt Nathalie J. , Lennette Edwin H.
Published: December 2020

Various types of rubella complement-fixing (CF) antigen preparations derived from infected BHK-21 cell cultures were examined for stability to certain chemical and physical agents. Antigens studied included: infected culture fluids concentrated 100-fold, ether-treated fluid concentrates, alkaline buffer extracts of infected cells, and large- and small-particle CF antigens separated by Sephadex gel filtration. All preparations were stable at -20 C for months, and were unaffected by three cycles of freezing and thawing. Ether treatment rendered antigens highly susceptible to thermal inactivation at 56 C; untreated antigens were inactivated slowly and showed a persistent fraction of activity even after 2 hr. Large-particle antigen was found to be slightly more susceptible than small-particle antigen to thermal inactivation and ether treatment. CF activity in alkaline buffer extracts was more labile than that in untreated or ether-treated fluid concentrates upon dialysis, Sephadex gel filtration, and sucrose density gradient centrifugation.
Florida Citrus Molasses as a Fermentation Substrate
Authors: Long Sterling K. , Hill E. C. , Wheaton T. A.
Published: December 2020

Samples of midseason Florida citrus molasses from 10 different manufacturing plants were studied during 2 years of production for suitability as fermentation substrates. They were analyzed for degrees Brix,
p
H, percentage of protein, and free amino acid content. The following ranges of values were obtained: degrees Brix, 65.4 to 73.0;
p
H, 4.2 to 6.4; and protein, 3.3 to 5.1%. Although the general characteristics of all samples were quite similar, the total free amino acid content and the number of amino acids differed from year to year and from plant to plant. The free amino acids consistently present were asparagine, aspartic acid, alanine, γ-amino-butyric, glycine, glutamic acid, proline, serine, and threonine. Occasionally found were arginine, histidine, isoleucine, leucine, lysine, phenylalanine, tyrosine, and valine. An extremely high level of proline was detected in all samples.
Aerobic Heterotrophic Bacterial Populations of Sewage and Activated Sludge
Authors: Prakasam T. B. S. , Dondero Norman C.
Published: December 2020

The nature and behavior of the microbial population developed on a synthetic waste containing salts and sorbitol are compared to that of a treatment-plant activated sludge. The population of the adapted sludge developed on the synthetic waste consisted approximately of only six kinds of bacteria. Experiments with radioactive sorbitol indicate that the microbial population developed on the synthetic waste showed the effects of repression by glucose on the metabolism of sorbitol; in contrast, the activated sludge from a plant treating primarily domestic waste was able to attack both substrates immediately and simultaneously.
Comparison of Mycobacterial Cultures on Agar and Lowenstein Medium
Authors: Lorian Victor
Published: December 2020

In a comparison of Lowenstein's medium with two agar media, 7H10 without and with the addition of Triton WR 1339, 4,100 sputa were planted on all three, yielding 803 (19.6%) positive cultures. The addition of Triton WR 1339 to the 7H10 medium made it possible to observe the cord formation directly on the isolation plates and did not alter, in any respect, the results obtained with the basic 7H10 medium. The agar media produced much earlier and more positive cultures than Lowenstein's medium. A greater number of cultures showed drug resistance on Lowenstein's medium as compared with the agar media.
Dehydrogenase Activity of
Pseudomonas
Species
Authors: Keenan T. W. , Bills D. D. , Lindsay R. C.
Published: December 2020

Single-strain cultures of
Pseudomonas fragi, P. fluorescens, P. putrefaciens
, and strains of two marine species,
Pseudomonas
type I and
Pseudomonas
type II, were found to be capable of reducing added acetaldehyde, proprionaldehyde, and butyraldehyde to the corresponding alcohols at 21 C. All species studied reduced propionaldehyde at 6 C.
P. fragi, Pseudomonas
type I, and
Pseudomonas
type II reduced butanone at 6 and 21 C.
P. fragi
and
Pseudomonas
type II reduced acetone at 21 C. Dehydrogenase activity was found in some cultures in which growth was not evident. Under aerobic conditions, a strain of
P. fragi
reduced added propionaldehyde to
n
-propanol quantitatively within 36 hr at 21 C.
Rate of Isolated Hemicellulose Degradation and Utilization by Pure Cultures of Rumen Bacteria
Authors: Dehority B. A.
Published: December 2020

Rate studies on the utilization or degradation (or both) of isolated hemicelluloses were conducted with six strains of rumen cellulolytic bacteria. Utilization was estimated by total pentose loss, and degradation values were based on solubilization of the hemicellulose in acidified 80% ethyl alcohol. With the various strains of ruminococci, degradation of flax and fescue grass hemicellulose was near the maximum within the first 12 hr of incubation. However, where applicable, the rates of utilization were considerably slower. Both degradation and utilization of corn hull hemicellulose occurred at much slower rates than observed with the other two substrates. With flax and fescue grass hemicellulose, the rates of degradation did not appear to be influenced by the organism's ability, or inability, to utilize the substrate as an energy source. The rates and extent of isolated hemicellulose degradation and utilization were compared between the cellulolytic ruminococci and three strains of bacteria isolated from the rumen with a xylan medium. Similar values were obtained with both types of bacteria. These observations would suggest that the cellulolytic ruminococci may be important in the overall fermentation of forage hemicelluloses in the rumen. The acidified 80% ethyl alcohol supernatant fluids, obtained from fermentations of isolated fescue grass hemicellulose by two strains of
Ruminococcus flavefaciens
, of which only one was able eventually to utilize the substrate, were investigated by thin-layer chromatography. Results indicated that soluble oligosaccharides were produced, which were observed to disappear gradually with time in fermentations with the utilizing strain and to accumulate in fermentations with the nonutilizing strain. Examination of the acidified 80% ethyl alcohol-insoluble residue hydrolysates, obtained from fermentations with the utilizing strain, revealed that the concentration of all the constituent sugars decreased uniformly.

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