bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of
13
C-Nuclear Magnetic Resonance to the Observation of Metabolic Interactions in Anaerobic Digestors
Authors: Runquist Elizabeth A. , Abbott Edwin H. , Armold Melvin T. , Robbins John E.
Published: January 2020

The utilization and conversion of glucose to volatile acids were monitored in anaerobic digestors by
13
C-nuclear magnetic resonance. Glucose was converted to lactate and acetate. Lactate was subsequently converted to propionate. The distribution of the labeled carbons in propionate suggested that minor amounts were produced via the randomizing pathway and that the major portion of propionate was derived from lactate.
Occurrence and Growth of Yeasts in Yogurts
Authors: Suriyarachchi V. R. , Fleet G. H.
Published: January 2020

Yogurts purchased from retail outlets were examined for the presence of yeasts by being plated onto oxytetracycline malt extract agar. Of the 128 samples examined, 45% exhibited yeast counts above 10
3
cells per g. A total of 73 yeast strains were isolated and identified as belonging to the genera
Torulopsis, Kluyveromyces, Saccharomyces, Candida, Rhodotorula, Pichia, Debaryomyces
, and
Sporobolomyces. Torulopsis candida
and
Kluyveromyces fragilis
were the most frequently isolated species, followed by
Saccharomyces cerevisiae, Rhodotorula rubra, Kluyveromyces lactis
, and
Torulopsis versatilis.
The growth of yeasts in yogurts was related to the ability of the yeasts to grow at refrigeration temperatures, to ferment lactose and sucrose, and to hydrolyze milk casein. Most yeast isolates grew in the presence of 100 μg of sorbate and benzoate preservatives per ml. Higher yeast counts from yogurts were obtained when the yogurts were plated onto oxytetracycline malt extract agar than when they were plated onto acidified malt extract agar.
Potential for Biodegradation of Phthalic Acid Esters in Marine Regions
Authors: Taylor Barrie F. , Curry Richard W. , Corcoran Eugene F.
Published: January 2020

Di-(2-ethylhexyl) phthalate was the major phthalic acid ester in the Mississippi River estuary, with mean levels of 0.1 μg/g (dry weight) in surface sediments, 1.0 μg/liter in river water, and 0.7 μg/liter in delta water. Bacteria that grew aerobically on dibutyl phthalate and
o
-phthalic acid were readily detected in the sediments and water. Pure cultures of bacteria were isolated on seven different phthalic acid esters from freshwater and marine sources. The marine isolates were taxonomically diverse and grew on a variety of phthalic acid esters. Dibutyl phthalate and
o
-phthalic acid supported growth in full-strength synthetic sea-water medium, but Na
+
-dependent catabolism was demonstrable only for
o
-phthalic acid.
Mechanism of
l
-Glutamine Production by an
l
-Glutamine-Producing Mutant of
Flavobacterium rigense
Authors: Nabe Koichi , Yamada Shigeki , Chibata Ichiro
Published: January 2020

Properties of some enzymes involved in
l
-glutamine biosynthesis in an
l
-glutamine-producing mutant of
Flavobacterium rigense
were examined. Glutamate-oxaloacetate transaminase in the mutant was nearly at the same level as that in the parent strain and was the most active among the enzymes participating in glutamate biosynthesis from α-ketoglutarate. Glutamine synthetase formation in the mutant was enhanced by increasing the concentration of (NH
4
)
2
-fumarate in the medium, but the activity of this enzyme in the parent strain was very low, and its formation was not influenced by the concentration of (NH
4
)
2
-fumarate. Glutaminase formation by both strains was similar and was not influenced by the levels of (NH
4
)
2
-fumarate. Glutaminase activity of the mutant was inhibited by ammonia and fumarate. Intracellular amino acids and extracellular free amino acids in the mutant were compared with those of the parent strain. It seems reasonable to conclude that
l
-glutamine leaks out specifically through the cell membrane of strain 703 and that this specific excretion of
l
-glutamine probably allows a continuous conversion of
l
-glutamate to
l
-glutamine inside the cell.
Determination of Microbial Populations with Piezoelectric Membranes
Authors: Ishimori Yoshio , Karube Isao , Suzuki Shuichi
Published: January 2020

The ultrasonic determination of microbial population was carried out by using a new apparatus composed of two piezoelectric membranes. When the apparatus was immersed in a medium containing cells and an arbitrary voltage was charged on a piezoelectric membrane, an output voltage was obtained from the other membrane. The output voltage increased with increasing cell numbers. The linear relationships between the output voltage and microbial populations of
Saccharomyces cerevisiae, Bacillus subtilis
, and
Klebsiella
sp. were observed, and the output voltage was reproducible with a relative error of 6%. Furthermore, the cell population of
S. cerevisiae
in a fermentor could be continuously determined with this apparatus.
Isolation of virulent Yersinia enterocolitica from porcine tongues
Authors: Doyle M P , Hugdahl M B , Taylor S L
Published: January 2020

Thirty-one tongues from apparently normal, freshly slaughtered pigs were assayed for the presence of Yersinia enterocolitica by different enrichment and postenrichment techniques. Sixteen different isolates were recovered, including six of serotype O:8, four of serotype O:6,30, two of serotype O:3 phage type IXb, and one each of serotypes O:13,7, O:18, and O:46. One isolate was not typable. Cold enrichment in phosphate-buffered saline followed by treatment with dilute KOH or subsequent enrichment in modified Rappaport broth recovered 12 and 7 isolates, respectively. Four of the same isolates were recovered from the same tongues by both procedures. Cold enrichment without a selective postenrichment treatment recovered two isolates. Direct enrichment in modified Rappaport broth or modified selenite broth was ineffective in recovering yersiniae, as no isolates were obtained by either method. All of the serotype O:8 isolates were virulent to mice, causing the death of adults after oral challenge. This is the first report that associates Y. enterocolitica serotype O:8 with a natural reservoir.
Nitrogen Mineralization by
Acanthamoeba polyphaga
in Grazed
Pseudomonas paucimobilis
Populations
Authors: Sinclair James L. , McClellan J. Forbes , Coleman David C.
Published: January 2020

Nitrogen mineralization was studied in a simple grazing system in which the protozoan
Acanthamoeba polyphaga
was grown with the bacterium
Pseudomonas paucimobilis
(two soil organisms isolated from the shortgrass prairie in northern Colorado). In different experiments, either carbon or nitrogen was adjusted to be in limiting amounts. When carbon was limiting, grazers were almost entirely responsible for nitrogen mineralization, with bacteria themselves contributing little. When nitrogen was limiting, nitrogen mineralization by grazers permitted continued growth by the grazed bacteria and a greater bacterial biomass production. The increased growth of the grazed bacteria did not result in an increased total amount of carbon used, but the grazed bacteria used carbon more efficiently than the ungrazed bacteria.
Immobilization of
Escherichia coli
Cells Containing Aspartase Activity with Polyurethane and Its Application for
l
-Aspartic Acid Production
Authors: Fusee Murray C. , Swann Wayne E. , Calton Gary J.
Published: January 2020

Whole cells of
Escherichia coli
containing aspartase activity were immobilized by mixing a cell suspension with a liquid isocyanate-capped polyurethane prepolymer (Hypol). The immobilized cell preparation was used to convert ammonium fumarate to
l
-aspartic acid. Properties of the immobilized
E. coli
cells containing aspartase were investigated with a batch reactor. A 1.67-fold increase in the
l
-aspartic acid production rate was observed at 37°C as compared to 25°C operating temperature. The pH optimum was broad, ranging from 8.5 to 9.2. Increasing the concentration of ammonium fumarate to 1.5 M from 1.0 M negatively affected the reaction rate.
l
-Aspartic acid was produced at an average rate of 2.18 × 10
−4
mol/min per g (wet weight) of immobilized
E. coli
cells with a 37°C substrate solution consisting of 1.0 M ammonium fumarate with 1 mM Mg
2+
(pH 9.0).
Rates of Transformation of Methyl Parathion and Diethyl Phthalate by Aufwuchs Microorganisms
Authors: Lewis David L. , Holm Harvey W.
Published: January 2020

Using batch cultures, we determined transformation rates for low concentrations of two toxicants—an insecticide, methyl parathion (
O,O
-dimethyl
O-p
-nitrophenyl phosphorothioate), and a plasticizer, diethyl phthalate—by aufwuchs, aquatic microbial growth attached to submerged surfaces or suspended in streamers or mats. Aufwuchs samples were collected from field sites, an indoor channel, and a continuous-flow fermentor. Aufwuchs fungi, protozoa, and algae did not transform methyl parathion or diethyl phthalate, but bacteria rapidly transformed both chemicals. Second-order transformation rate coefficients,

K
b

, based on total plate counts of bacteria in aufwuchs, were determined for potential use in a mathematical model capable of predicting the transport and fate of chemicals in aquatic systems.

K
b

for both methyl parathion and diethyl phthalate decreased as the concentration of total bacteria, [B], increased in aufwuchs. This effect resulted from the proportion of nontransformer to transformer bacteria increasing as [B] increased and from the rate of transformation per transformer cell decreasing as [B] increased. First-order transformation rate coefficients,

K
1

, were relatively stable per unit of surface area colonized by aufwuchs, because

K
b

decreased as [B] increased (
K
1
=

K
b

× [B]).
Gauze Filtration and Enrichment Procedures for Recovery of
Vibrio cholerae
from Contaminated Waters
Authors: Spira W. M. , Ahmed Q. S.
Published: January 2020

Gauze filtration followed by 18-h enrichment in alkaline bile-peptone water is a simple, inexpensive, and efficient method for isolation
Vibrio cholerae
biotype
eltor
from contaminated surface waters.
Attachment and Rosette Formation by Hyphomicrobia
Authors: Moore Richard L. , Marshall Kevin C.
Published: January 2020

The processes of reversible and irreversible sorption of
Hyphomicrobium
sp. strain ZV580 to solid surfaces was investigated with the use of swarmer cell populations. Various compounds and physical conditions were examined for their effect on the cell-cell interactions which lead to the formation of rosette-like cell aggregates. The monosaccharides galactose and mannose were able to completely inhibit rosette formation. Concanavalin A and chloramphenicol were also able to prevent rosette formation, and both trypsin and pronase caused the disassociation of rosettes. The results indicate that the adhesin is a glycoprotein or a peptido-polysaccharide and that the flagellum may act as a vehicle for the transport of this adhesin from the cell to a surface.
Source and extent of Klebsiella pneumoniae in the paper industry
Authors: Caplenas N R , Kanarek M S , Dufour A P
Published: January 2020

Three pulp and paper mill processing plants were evaluated for fecal coliform and Klebsiella pneumoniae bacterial concentrations. Freshwater consumed by paper industries contained minimum detectable levels of K. pneumoniae, less than 10 organisms per 100 ml. Elevated concentrations of K. pneumoniae could be traced from early pulping stages to water processing reuse systems. Concentrations of K. pneumoniae (thermotolerant and thermointolerant) ranged from 40,000 organisms per 100 ml to an estimated 3 x 10(6) organisms per 100 ml. K. pneumoniae biotyping provided evidence for the selective growth and persistence of K. pneumoniae from the initial wood washing stages through to the final effluent discharge. Wastewater treatment had limited effects in reducing K. pneumoniae concentrations. K. pneumoniae levels ranged from 40 organisms per 100 ml to an estimated 10(6) organisms per 100 ml. The presence of K. pneumoniae in water indicates degraded water quality, and its significance with regard to human health effects has yet to be examined.
Conjugal Transfer of R-Plasmid R1
drd-19
in
Escherichia coli
Below 22°C
Authors: Singleton Paul , Anson Avril E.
Published: January 2020

The conjugal transfer of R-plasmids is known to occur at temperatures above 22°C. We found that R1
drd-19
is transferable below 22°C, and we discuss this finding in the context of plasmid transfer in environmental waters.
Synthesis of 1,2-Epoxyoctane by
Pseudomonas oleovorans
During Growth in a Two-Phase System Containing High Concentrations of 1-Octene
Authors: de Smet Marie-José , Wynberg Hans , Witholt Bernard
Published: January 2020

We have optimized and compared the synthesis of 1,2-epoxyoctane from 1-octene by resting and by growing cells of
Pseudomonas oleovorans.
The net production of 1,2-epoxyoctane by resting cells never exceeded 0.6 mg/ml of suspension. In contrast,
P. oleovorans
produced much more epoxide when it was grown on high levels of 1-octene. To raise the total production of epoxide, the octene layer was repeatedly transferred to fresh, growing cultures of
P. oleovorans.
By using this approach, a maximum of 28 mg of epoxide was synthesized per ml of total culture, resulting in the accumulation of ca. 75 mg of epoxide per ml in the octene phase.
Characteristics of the
Drosophila paulistorum
Male Sterility Agent in a Secondary Host,
Ephestia kuehniella
Authors: Gottlieb F. J. , Simmons G. M. , Ehrman L. , Inocencio B. , Kocka J. , Somerson N.
Published: January 2020

Crosses among the six semispecies of
Drosophila paulistorum
produce sterile male hybrids. This sterility is caused by an agent which has characteristics of a microorganism. It is pathogenic in a secondary host, the larvae of the Mediterranean meal moth,
Ephestia kuehniella
, and can be serially passaged in
Ephestia
, where it is lethal. The agent was passaged back into
D. paulistorum
, where it induced sterility in males of a semispecies different from that of origin of the agent. Infectious particles were obtained from an extract of infected
Ephestia
by ultracentrifugation in a sucrose-Ficoll-metrizamide gradient. Both crude and purified extracts were lyophilized and stored indefinitely without loss of killing power. The agent was destroyed by low pH, lipid solvents, ultraviolet light, and exposure to a temperature of 56°C for 30 min. It appeared to be sensitive to tetracycline and insensitive to penicillin, suggesting that the agent is not a virus, but more likely a cell wall-deficient bacterium or mycoplasma-like organism.
Effects of Long-Chain Fatty Acids on Growth of Rumen Bacteria
Authors: Maczulak A. E. , Dehority B. A. , Palmquist D. L.
Published: January 2020

The effects of low concentrations of long-chain fatty acids (palmitic, stearic, oleic, and vaccenic) on the growth of seven species (13 strains) of rumen bacteria were investigated. Except for
Bacteroides ruminicola
and several strains of
Butyrivibrio fibrisolvens
, bacterial growth was not greatly affected by either palmitic or stearic acids. In contrast, growth of
Selenomonas ruminantium, B. ruminicola
, and one strain of
B. fibrisolvens
was stimulated by oleic acid, whereas the cellulolytic species were markedly inhibited by this acid. Vaccenic acid (
trans
Δ11 18:1) had far less inhibitory effect on the cellulolytic species than oleic acid (
cis
Δ9 18:1). Inclusion of powdered cellulose in the medium appeared to reverse both inhibitory and stimulatory effects of added fatty acids. However, there was little carry-over effect observed when cells were transferred from a medium with fatty acids to one without. Considerable variation in response to added fatty acids was noted among five strains of
B. fibrisolvens
. In general, exogenous long-chain fatty acids appear to have little, if any, energy-sparing effect on the growth of rumen bacteria.
Liquid Chromatographic Procedure for Fermentation Product Analysis in the Identification of Anaerobic Bacteria
Authors: Ehrlich Garry G. , Goerlitz Donald F. , Bourell James H. , Eisen Grant V. , Godsy Edward M.
Published: January 2020

High-performance liquid chromatography with a cation-exchange resin-packed column was used to determine fermentation products of several known and unknown
Clostridium
species. The column was operated at 30°C, and isocratic elution was done with 0.013 N H
2
SO
4
. Sample preparation for high-performance liquid chromatographic analysis required only membrane filtration. Glucose and formate were readily determined. Quantitative results were easily obtained. Chromatograms of eight unknown strains could be matched with chromatograms of at least one of the type culture strain chromatograms. In some cases, additional testing was necessary before identification could be made. The same conclusions were reached by parallel testing with gas chromatography to determine fermentation products. High-performance liquid chromatography is simple to apply and, under some conditions, is faster than gas chromatography for fermentation product analysis.
Verruculogen Produced by soil fungi in England and Wales
Authors: Patterson D S , Shreeve B J , Roberts B A , MacDonald S M
Published: January 2020

Soil fungi, including Aspergillus fischeri, Penicillium piceum, Penicillium nigricans, and Penicillium raistrickii, produced a tremorgenic toxin previously described as toxin X. Chemical analysis showed that this toxin was predominantly verruculogen.
Detection of Clostridium botulinum type G toxin by enzyme-linked immunosorbent assay
Authors: Lewis G E , Kulinski S S , Reichard D W , Metzger J F
Published: January 2020

Clostridium botulinum type G toxin was detected and quantified readily with the enzyme-linked immunosorbent assay. With the double-sandwich technique and alkaline phosphatase as the enzyme indicator, C. botulinum toxin type G was detected in quantities equaling those required for one mouse intraperitoneal median lethal dose. The time required for the procedure was approximately 6.5 h, but this requirement could have been reduced to 5.5 h or less with the use of precoated plates stored at -70 degrees C. Cross-reactions did not occur with culture extracts of C. sporogenes of C. botulinum types B, C, D, E, and F. Acidic preparations of C. botulinum type A exhibited nonspecific reactivity. Likewise, 50% of the C. subterminale isolates tested were cross-reactive in the assay. These latter isolates express similar metabolic and physiological characteristics with C. botulinum type G.
Role of pH, lactate, and anaerobiosis in controlling the growth of some fermentative Gram-negative bacteria on beef
Authors: Grau F H
Published: January 2020

At 5 degrees C four strains of fermentative, gram-negative bacteria (Serratia liquefaciens, Yersinia enterocolitica, Enterobacter cloacae, and Aeromonas hydrophila) grew aerobically and anaerobically on adipose tissue removed from beef muscle of low pH (5.4 to 5.6). All four strains also grew aerobically and anaerobically on muscle tissue of high pH (6.0 to 6.3). However, none of the four grew anaerobically on beef muscle of low pH, and the aeromonad strain also failed to grow aerobically on such muscle. Growth of S. liquefaciens and E.cloacae on vacuum-packaged beef muscle was dependent on the pH of the tissue and the oxygen transmission rate of the packaging film. Although the four strains grew in broth buffered at pH 5.55, L-lactate, at the concentration found in muscle of low pH (ca. 100 mM), prevented anaerobic growth of all four isolates and prevented the aerobic growth of th aeromonad. At pH 6.1 in buffered broth, the concentration of L-lactate occurring in muscle of high pH did not prevent aerobic or anaerobic growth of any of the strains.
Formation of (4R)- and (4S)-4-hydroxyochratoxin A from ochratoxin A by liver microsomes from various species
Authors: Størmer F C , Hansen C E , Pedersen J I , Hvistendahl G , Aasen A J
Published: January 2020

Two metabolic products were formed from ochratoxin A by human, pig, and rat liver microsomal fractions in the presence of reduced nicotinamide adenine dinucleotide phosphate. They were isolated from the incubation mixture in the presence of pig liver microsomes by extraction, thin-layer chromatography, and high-pressure liquid chromatography Their structures are suggested to be (4R)- and (4S)-4-hydroxyochratoxin A on the basis of mass and nuclear magnetic resonance spectroscopy. Km and the maximum velocity for the formation of the two metabolites by human, pig, and rat microsomes were determined. Their formation was inhibited by carbon monoxide and metyrapone. The results indicate that the microsomal hydroxylation system is a cytochrome P-450 and that different species are involved in the formation of the two epimeric forms of 4-hydroxyochratoxin A.
Cellulose Fermentation by a Rumen Anaerobic Fungus in Both the Absence and the Presence of Rumen Methanogens
Authors: Bauchop Thomas , Mountfort Douglas O.
Published: January 2020

The fermentation of cellulose by an ovine rumen anaerobic fungus in the absence and presence of rumen methanogens is described. In the monoculture, moles of product as a percentage of the moles of hexose fermented were: acetate, 72.7; carbon dioxide, 37.6; formate, 83.1; ethanol, 37.4; lactate, 67.0; and hydrogen, 35.3. In the coculture, acetate was the major product (134.7%), and carbon dioxide increased (88.7%). Lactate and ethanol production decreased to 2.9 and 19%, respectively, little formate was detected (1%), and hydrogen did not accumulate. Substantial amounts of methane were produced in the coculture (58.7%). Studies with [2-
14
C]acetate indicated that acetate was not a precursor of methane. The demonstration of cellulose fermentation by a fungus extends the range of known rumen organisms capable of participating in cellulose digestion and provides further support for a role of anaerobic fungi in rumen fiber digestion. The effect of the methanogens on the pattern of fermentation is interpreted as a shift in flow of electrons away from electron sink products to methane via hydrogen. The study provides a new example of intermicrobial hydrogen transfer and the first demonstration of hydrogen formation by a fungus.
Elaboration of vomitoxin and zearalenone by Fusarium isolates and the biological activity of Fusarium-produced toxins
Authors: Vesonder R F , Ellis J J , Rohwedder W K
Published: January 2020

Sixteen Fusarium isolates belonging to F. graminearium Schw. and F. culmorum (W.G. Smith) Sacc. produced vomitoxin and zearalenone on cracked corn at 28 degrees C. Quantitation for vomitoxin was by gas-liquid chromatography. This toxin was produced in quantities of 5 to 236 microgram/g of fermented corn. Vomitoxin showed weak antibiotic activity against Penicillium digitatum Sacc., Mucor ramannianus Möller, and Saccharomyces bayanus Sacc., but did not inhibit gram-positive, gram-negative, or acid fast bacteria. The two molds and the yeast were inhibited by T-2 toxin at 5 micrograms, and diacetoxyscirpenol inhibited the molds at 5 micrograms and the yeast at 50 micrograms.
Evidence for Plasmid Linkage of Restriction and Modification in
Streptococcus cremoris
KH
Authors: Sanders M. E. , Klaenhammer T. R.
Published: January 2020

Restriction and modification have been demonstrated in
Streptococcus cremoris
KH cells when infected by
Streptococcus lactis
C2 phage (designated c2) at an efficiency of plating of 2 × 10
−7
. The growth of c2 phage through KH cells produces modified progeny phage capable of unrestricted growth on KH cells. The ability of single-colony isolates of
S. cremoris
KH cultures to restrict and modify c2 phage was found to be variable. From 2 to 6.5% of colonies isolated were partially deficient in restrictive capacity, permitting a greater plaquing ability by c2 phage of 1.8 to 2.9 log cycles. No completely restrictionless mutants were isolated from 1,000 colonies examined. Mutants were shown to be deficient in both restriction and modification capabilities of the same specificity. The frequent occurrence of a genotypic change that resulted in the loss of both restriction and modification capacities indicated the involvement of plasmid deoxyribonucleic acid in genetically determining this specific restriction and modification system.
S. cremoris
KH was found to harbor 11 plasmid molecules, with molecular weights (×10
6
) estimated to be 50, 41, 24, 18, 10, 7.4, 3.3, 3.0, 2.8, 2.5, and 1.5. Of the 27 mutants examined, 25 were missing the 10-megadalton plasmid. This consistent plasmid difference among the majority of mutants isolated supports the involvement of this plasmid in restriction and modification. Plasmid linkage of restriction and modification systems provides a genetic mechanism for the rapid development of phage-sensitive starter cultures due to the inherent instability of extrachromosomal elements.
Bacterial spore components which enhance the bacteriostatic effectiveness of S-nitrosothiol
Authors: Morris S L , Hansen J N
Published: January 2020

Spore components exuded into the medium during outgrowth of Bacillus cereus T enhanced the bacteriostatic effectiveness of S-nitrosomercaptoethanol, an inhibitor which prevents outgrowth at low concentrations and germination at higher concentrations. The enhancement effect was slight with respect to outgrowth, but dramatic with respect to germination, in that the inhibitory effectiveness of nitrosothiols toward germination inhibition was enhanced by as much as 33-fold when nitrosothiols was in the presence of the exuded spore component. Exudate activity was freely dialyzable and was not measurably affected by a broad-spectrum protease (proteinase K), by autoclaving at 121 degrees C, or by freezing and thawing. Sephadex G-25 chromatography of the exudate indicated that two active species were present, a major component with a molecular weight of less than 1,000 and a minor component with a molecular weight of more than 5,000.
Poliovirus Adsorption by 34 Minerals and Soils
Authors: Moore Rebecca S. , Taylor Dene H. , Sturman Lawrence S. , Reddy Michael M. , Fuhs G. Wolfgang
Published: January 2020

The adsorption of radiolabeled infectious poliovirus type 2 by 34 well-defined soils and mineral substrates was analyzed in a synthetic freshwater medium containing 1 mM CaCl
2
and 1.25 mM NaHCO
3
at pH 7. In a model system, adsorption of poliovirus by Ottawa sand was rapid and reached equilibrium within 1 h at 4°C. Near saturation, the adsorption could be described by the Langmuir equation; the apparent surface saturation was 2.5 × 10
6
plaque-forming units of poliovirus per mg of Ottawa sand. At low surface coverage, adsorption was described by the Freundlich equation. The soils and minerals used ranged from acidic to basic and from high in organic content to organic free. The available negative surface charge on each substrate was measured by the adsorption of a cationic polyelectrolyte, polydiallyldimethylammonium chloride. Most of the substrates adsorbed more than 95% of the virus. In general, soils, in comparison with minerals, were weak adsorbents. Among the soils, muck and Genesee silt loam were the poorest adsorbents; among the minerals, montmorillonite, glauconite, and bituminous shale were the least effective. The most effective adsorbents were magnetite sand and hematite, which are predominantly oxides of iron. Correlation coefficients for substrate properties and virus adsorption revealed that the elemental composition of the adsorbents had little effect on poliovirus uptake. Substrate surface area and pH, by themselves, were not significantly correlated with poliovirus uptake. A strong negative correlation was found between poliovirus adsorption and both the contents of organic matter and the available negative surface charge on the substrates as determined by their capacities for adsorbing the cationic polyelectrolyte, polydiallyldimethylammonium chloride.
Possible waterborne transmission and maintenance of influenza viruses in domestic ducks
Authors: Markwell D D , Shortridge K F
Published: January 2020

Two duck farms in Hong Kong were examined monthly for 1 year for the occurrence and persistence of influenza viruses within the duck communities. The predominant virus in one community was H3N2, a virus antigenically related to the pandemic Hong Kong strain. This virus was isolated monthly throughout the year from feces or pond water or both, indicating a cycle of waterborne transmission. Viruses of the same antigenic combination were isolated 1 and 2 years after the last sampling occasion, implying persistence in the community. Infection was asymptomatic. Maintenance of virus appeared to be dependent upon the continual introduction of ducklings susceptible to infection onto virus-contaminated water; the feces of ducks 70 to 80 days old were generally free of detectable virus despite the exposure of the ducks to virus in pond water. In the second community, in which ducklings were not introduced after the initial sampling, the prevailing viruses, H7N1 and H7N2, also present asymptomatically, ceased to be detected once the ducks were 70 to 80 days old. The normal practice of raising ducks of different ages on the same farm, wherein the water supplies are shared, as typified by the first community, appears to be instrumental in maintaining a large reservoir of influenza viruses in the duck population of southern China.
Effects of Petroleum Hydrocarbons on Plant Litter Microbiota in an Arctic Lake
Authors: McKinley Vicky L. , Federle Thomas W. , Vestal J. Robie
Published: January 2020

The effects of petroleum hydrocarbons on the microbial community associated with decomposing
Carex
leaf litter colonized in Toolik Lake, Alaska, were examined. Microbial metabolic activity, measured as the rate of acetate incorporation into lipid, did not vary significantly from controls over a 12-h period after exposure of colonized
Carex
litter to 3.0 ml of Prudhoe Bay crude oil, diesel fuel, or toluene per liter. ATP levels of the microbiota became elevated within 2 h after the exposure of the litter to diesel fuel or toluene, but returned to control levels within 4 to 8 h. ATP levels of samples exposed to Prudhoe Bay crude oil did not vary from control levels. Mineralization of specifically labeled
14
C-[lignin]-lignocellulose and
14
C-[cellulose]-lignocellulose by Toolik Lake sediments, after the addition of 2% (vol/vol) Prudhoe Bay crude oil, motor oil, diesel fuel, gasoline,
n
-hexane, or toluene, was examined after 21 days of incubation at 10°C. Diesel fuel, motor oil, gasoline, and toluene inhibited
14
C-[lignin]-lignocellulose mineralization by 58, 67, 67, and 86%, respectively. Hexane-treated samples displayed an increase in the rate of
14
C-[lignin]-lignocellulose mineralization of 33%.
14
C-[cellulose]-lignocellulose mineralization was inhibited by the addition of motor oil or toluene by 27 and 64%, respectively, whereas diesel fuel-treated samples showed a 17% increase in mineralization rate. Mineralization of the labeled lignin component of lignocellulose appeared to be more sensitive to hydrocarbon perturbations than was the labeled cellulose component.
Development of a two-step enrichment procedure for recovery of Yersinia enterocolitica from food
Authors: Schiemann D A
Published: January 2020

Two new enrichment media were formulated for the recovery of Yersinia enterocolitica from foods: (i) yeast extract-rose bengal broth for preenrichment at 4 or 10 degrees C; and (ii) bile-oxalate-sorbose broth, a selective enrichment incubated at 22 degrees C. Comparison of these media in a two-step enrichment procedure against cold enrichment and modified Rappaport broth showed improved and more rapid recovery of human strains of Y. enterocolitica from inoculated foods. The use of bile-oxalate-sorbose broth as a selective enrichment also improved the performance of cold enrichment with phosphate-buffered saline. Determination of the best enrichment system for recovery of Y. enterocolitica from samples of retail pork and fresh pork tongues depended on whether the criterion was the number of positive samples, the variety of different serotypes recovered, or the ability to recover the important human serotype O:3. A single enrichment system with the widest selectivity would include preenrichment at 4 degrees C with either phosphate-buffered saline for 14 days or yeast extract-rose bengal broth for 9 days followed by selective enrichment with bile-oxalate-sorbose broth at 22 degrees C for 5 days.
Diversity Dynamics of Marine Bacteria Studied by Immunofluorescent Staining on Membrane Filters
Authors: Dahle Arne B. , Laake Morten
Published: January 2020

Of 34 strains of marine bacteria isolated on a general seawater medium, 5 were selected for detailed studies of their population dynamics in the plankton. The isolates were characterized as
Aeromonas
sp.,
Chromobacterium
cf.
lividum, Vibrio
sp., and two
Pseudomonas
spp. Specific antibodies were produced by immunization of rabbits, and bacterial cells were stained on black Uni-Pore membrane filters by an indirect immunofluorescent staining procedure. The method proved to be very specific and practical for use in a large-scale field sampling program. Growth of all five isolates was stimulated by high values for net primary production, chlorophyll
a
, and dissolved organic carbon. Calculation of a diversity index based on specific and total counts is proposed as a way of characterizing the dynamics of organotrophic bacterial populations in the sea.
Contribution of Particle-Bound Bacteria to Total Microheterotrophic Activity in Five Ponds and Two Marshes
Authors: Kirchman David , Mitchell Ralph
Published: January 2020

We examined the abundance and heterotrophic uptake of bacteria attached to particulate matter suspended in five coastal ponds and two marshes near Woods Hole, Mass. Although the number of particle-bound bacteria was low (<10%), these bacteria incorporated a large proportion (>40%) of [
14
C]glucose and [
14
C]glutamate in selected aquatic systems. The uptake per cell was significantly higher for epibacteria than for unattached bacteria in all systems. Two groups of the aquatic environments sampled were statistically different in the contribution made by particle-bound bacteria to total bacterial abundance and to total assimilation of [
14
C]glucose and [
14
C]glutamate. Particle-bound bacteria were more important in those waters with a high particle concentration and not flushed regularly by tides than in waters with a low particle concentration and flushed regularly.
Influence of pH on Inhibitory Activity of Acetic Acid on Osmophilic Yeasts Used in Brine Fermentation of Soy Sauce
Authors: Noda Fumio , Hayashi Kazuya , Mizunuma Takeji
Published: January 2020

The inhibitory activity of acetic acid on osmophilic yeasts (
Saccharomyces rouxii
and
Torulopsis versatilis
) used for the brine fermentation of soy sauce increased remarkably as the pH of the medium was lowered. This increased toxicity could not be attributed to a hydrogen ion effect alone.
Lack of Mutagenicity of the Fungicide 2,4,5,6-Tetrachloroisophthalonitrile in the Ames
Salmonella
/Microsome Test
Authors: Wei Cheng-I
Published: January 2020

The fungicide 2,4,5,6-tetrachloroisophthalonitrile was found to be not mutagenic to five
Salmonella typhimurium
tester strains. Incorporation of either a liver or a kidney activation system did not increase the mutagenic activity of the fungicide.
Simple and convenient method for culturing anaerobic bacteria
Authors: Behbehani M J , Jordan H V , Santoro D L
Published: January 2020

A simple and convenient method for culturing anaerobic bacteria is described. Cultures can be grown in commercially available flasks normally used for preparation of sterile external solutions. A special disposable rubber flask closure maintains anaerobic conditions in the flask after autoclaving. Growth of a variety of anaerobic oral bacteria was comparable to that obtained after anaerobic incubation of broth cultures in Brewer Anaerobic Jars.
Comparison of coliphage and bacterial aerosols at a wastewater spray irrigation site
Authors: Bausum H T , Schaub S A , Kenyon K F , Small M J
Published: January 2020

Microbiological aerosols were measured on a spray irrigation site at Fort Huachuca, Ariz. Indigenous bacteria and tracer bacteriophage were sampled from sprays of chlorinated and unchlorinated secondary-treatment wastewaters during day and night periods. Aerosol dispersal and downwind migration were determined. Bacterial and coliphage f2 aerosols were sampled by using Andersen viable type stacked-sieve and high-volume electrostatic precipitator samplers. Bacterial standard plate counts averaged 2.4 x 10(5) colony-forming units per ml in unchlorinated effluents. Bacterial aerosols reached 500 bacteria per m3 at 152 m downwind and 10,500 bacteria per m3 at 46m. Seeded coliphage f2 averaged 4.0 x 10(5) plaque-forming units per ml in the effluent and were detected 563 m downwind. Downwind microbial aerosol levels were somewhat enhanced by nighttime conditions. The median aerodynamic particle size of the microbial aerosols was approximately 5.0 micrometer. Chlorination reduced wastewater bacterial levels 99.97% and reduced aerosol concentrations to near background levels; coliphage f2 was reduced only 95.4% in the chlorinated effluent and was readily measured 137 m downwind. Microbiological source strength an meteorological data were used in conjunction with a dispersion model to generate mathematical predictions of aerosol strength at various sampler locations. The mean calculated survival of aerosolized bacteria (standard plate count) in the range 46 to 76 m downwind was 5.2%, and that of coliphage f2 was 4.3 %.
Terminal Reactions in the Anaerobic Digestion of Animal Waste
Authors: Boone David R.
Published: January 2020

An anaerobic mesophilic digestor was operated using beef cattle waste (diluted to 5.75% volatile solids) as substrate; retention time was 10 days with daily batch feed. Volatile solids destruction was 36%. Daily gas production rate was 1.8 liters of gas (standard temperature and pressure) per liter of digestor contents (0.99 liters of CH
4
per liter of digestor contents). Acetate turnover was measured, and it was calculated that 68% of the CH
4
was derived from the methyl group of acetate. When the methanogenic substrates acetic acid or H
2
/CO
2
were added to the digestor on a continuous basis, the microflora were able to adapt and convert them to terminal products while continuing to degrade animal waste to the same extent as without additions. The methanogenic substrates were added at a rate at least 1.5 times the microbial production rate which was measured in the absence of added substrates. Added acetate was converted directly to CH
4
by acetoclastic methanogens; H
2
addition greatly stimulated acetate production in the digestor. A method is described for the measurement of acetate turnover in batch-fed digestors.
CDP-diacylglycerol synthase activity in Clostridium perfringens
Authors: Carman G M , Zaniewski R L , Cousminer J J
Published: January 2020

CTP:phosphatidate cytidylyltransferase (CDP-diacylglycerol synthase; EC 2.7.7.41) was identified in the cell envelope fraction of the gram-positive anaerobe Clostridium perfringens. The association of this enzyme with the cell envelope fraction of cell extracts was demonstrated by glycerol density gradient centrifugation and by activity sedimenting with the 100,000 x g pellet. The enzyme exhibited a broad pH optimum between pH 6.5 and pH 7.5. Enzyme activity was dependent on magnesium (5 mM) or manganese (1 mM) ions. Activity was also dependent on the addition of the nonionic detergent Triton X-100 (5 mM). The apparent Km values for CTP and phosphatidic acid were 0.18 mM and 0.22 mM, respectively. Thioreactive agents inhibited activity, indicating that a sulfhydryl group is essential for activity. Maximal enzyme activity was observed at 50 degrees C.
Influence of diluents, media, and membrane filters on detection fo injured waterborne coliform bacteria
Authors: McFeters G A , Cameron S C , LeChevallier M W
Published: January 2020

Pure cultures of Escherichia coli, Klebsiella pneumoniae, Enterobacter aerogenes, and Citrobacter freundii were injured ( greater than 90%) in water from a dead-end section of the Bozeman, Montana, distribution system. The effects of the following laboratory variables on the enumeration efficiency of injured and undamaged control cells were examined: (i) diluent composition, temperature, and time of exposure; (ii) media, using various formulations employed in enumerating gram-negative bacteria; and (iii) surface pore morphology of membrane filters. The addition of peptone or milk solids to diluents and low temperature (4 degrees C) maximized the recovery of injured cells, but had little effect on undamaged cells. Control cells were recovered with high efficiencies on most media tested, but recoveries of injured cells ranged from 0 to near 100%. Most of the media commonly used in water analysis recovered less than 30% of injured cells. This was explained in part by the sensitivity of injured bacteria to deoxycholate concentrations greater than 0.01%, whereas control cells were unaffected by 0.1%. Membrane filter surface pore morphology (at 35 degrees C) had a negligible effect on total coliform recoveries. Recommendations are made regarding procedures to improve the recovery of injured coliforms by routine laboratory practices.
New approach to tryptophan production by Escherichia coli: genetic manipulation of composite plasmids in vitro
Authors: Aiba S , Tsunekawa H , Imanaka T
Published: January 2020

For the purpose of studying the production of L-tryptophan by Escherichia coli, the deletion mutants of the trp operon (trpAE1) were transformed with mutant plasmids carrying the trp operon whose anthranilate synthase and phosphoribosyl anthranilate transferase (anthranilate aggregate), respectively, had been desensitized to tryptophan inhibition. In addition to release of the anthranilate aggregate from the feedback inhibition required for plasmids such as pSC101 trp.I15, the properties of trp repression (trpR) and tryptophanase deficiency (tnaA) were both indispensable for host strains such as strain Tna (trpAE1 trpR tnaA). The gene dosage effects on tryptophan synthase activities and on production of tryptophan were assessed. A moderate plasmid copy number, approximately five per chromosome, was optimal for tryptophan production. Similarly, an appropriate release of the anthranilate aggregate from feedback inhibition was also a necessary step to ward off the metabolic anomaly. If the mutant plasmid pSC101 trp-I15 was further mutagenized (pSC101 trp.I15.14) and then transferred to Tna cells, an effective enhancement of tryptophan production was achieved. Although further improvement of the host-plasmid system is needed before commercial production of tryptophan can be realized by this means, a promising step toward this goal has been established.
Lysogenic Strains of Lactic Acid Streptococci and Lytic Spectra of Their Temperate Bacteriophages
Authors: Reyrolle J. , Chopin M. C. , Letellier F. , Novel G.
Published: January 2020

A total of 113 strains of mesophilic strains lactic streptococci of the species
Streptococcus lactis, S. lactis
subsp.
diacetilactis
, and
S. cremoris
, chosen from 291 strains that had been previously classified into six groups on the basis of their sensitivity to 132 virulent phages, were subjected to induction with mitomycin C. Among these strains, 43% produced phages capable of forming plaques of lysis on an indicator strain either spontaneously or after induction. There was a close correlation between the lytic spectra of temperate and virulent phages. Among the strains studied, 25% were shown to be indicator strains. These results emphasized the high probability of development of temperate phages in a starter culture containing mesophilic lactic streptococci and therefore their importance as a cause of accidents in cheese making.
Chromosomal mapping of a gene affecting enterotoxin A production in Staphylococcus aureus
Authors: Mallonee D H , Glatz B A , Pattee P A
Published: January 2020

In a previous study, transformation demonstrated that a gene governing enterotoxin A production (entA+) in Staphylococcus aureus strain S-6 was located on the chromosome between the purB110 and ilv-129 markers; in contrast, the entA+ gene of strain FRI-196E was shown not to be located in the same position. In the current study, 54 enterotoxin A-producing strains of S. aureus were examined to locate the entA+ gene. Conventional transformation procedures and a series of multiply marked derivatives of NCTC 8325 were used as recipients for chromosomal mapping. Of the 54 strains tested, 23 were found to contain the entA+ gene at the original locus between the purB110 and ilv-129 markers. Twenty-seven strains could not be analyzed either because their DNA was genetically ineffective in transforming strain 8325 (23 strains), or Pur+ Ilv+ transformants could not be recovered (four strains). Four other strains contained an entA+ gene that could not be located in any of the chromosomal linkage groups. A new insertion site for Tn551 was located within the hla+ gene involved in alpha-toxin production. It eliminated alpha-toxin production and was used to separate the entA+ gene from the hla+ marker in the purB110-ilv-129 region. This segment of the chromosome is shown to consist of the purB110, entA+, hla+, and ilv-129 markers in that order.
Factors Affecting Yield and Safety of Protein Production from Cassava by
Cephalosporium eichhorniae
Authors: Mikami Y. , Gregory K. F. , Levadoux W. L. , Balagopalan C. , Whitwill S. T.
Published: January 2020

The properties of
Cephalosporium eichhorniae
152 (ATCC 38255) affecting protein production from cassava carbohydrate, for use as an animal feed, were studied. This strain is a true thermophile, showing optimum growth at 45° to 47°C, maximum protein yield at 45°C, and no growth at 25°C. It has an optimum pH of about 3.8 and is obligately acidophilic, being unable to sustain growth at pH 6.0 and above in a liquid medium, or pH 7.0 and above on solid media. The optimum growth conditions of pH 3.8 and 45°C were strongly inhibitive to potential contaminants. It rapidly hydrolyzed cassava starch. It did not utilize sucrose, but some (around 16%) of the small sucrose component of cassava was chemically hydrolyzed during the process. Growth with cassava meal (50 g/liter [circa 45 g/liter, glucose equivalent]) was complete in around 20 h, yielding around 22.5 g/liter (dry biomass), containing 41% crude protein (48 to 50% crude protein in the mycelium) and 31% true protein (7.0 g/liter). Resting and germinating spores (10
6
to 10
8
per animal) injected by various routes into normal and γ-irradiated 6-week-old mice and 7-day-old chickens failed to initiate infections.
Effects of Plutonium on Soil Microorganisms
Authors: Wildung Raymond E. , Garland Thomas R.
Published: January 2020

As a first phase in an investigation of the role of the soil microflora in Pu complex formation and solubilization in soil, the effects of Pu concentration, form, and specific activity on microbial types, colony-forming units, and CO
2
evolution rate were determined in soils amended with C and N sources to optimize microbial activity. The effects of Pu differed with organism type and incubation time. After 30 days of incubation, aerobic sporeforming and anaerobic bacteria were significantly affected by soil Pu levels as low as 1 μg/g when Pu was added as the hydrolyzable
239
Pu(NO
3
)
4
(solubility, <0.1% in soil). Other classes of organisms, except the fungi, were significantly affected at soil Pu levels of 10 μg/g. Fungi were affected only at soil Pu levels of 180 μg/g. Soil CO
2
evolution rate and total accumulated CO
2
were affected by Pu only at the 180 μg/g level. Because of the possible role of resistant organisms in complex formation, the mechanisms of effects of Pu on the soil fungi were further evaluated. The effect of Pu on soil fungal colony-forming units was a function of Pu solubility in soil and Pu specific activity. When Pu was added in a soluble, complexed form [
238
Pu
2
(diethylenetriaminepentaacetate)
3
], effects occurred at Pu levels of 1 μg/g and persisted for at least 95 days. Toxicity was due primarily to radiation effects rather than to chemical effects, suggesting that, at least in the case of the fungi, formation of Pu complexes would result primarily from ligands associated with normal (in contrast to chemically-induced) biochemical pathways.