bluuebunny/crossref_metadata_2025 huggingface dataset:
Virulence prediction of Yersinia enterocolitica by pyrolysis gas-liquid chromatography
Authors: Stern N J , Kotula A W , Pierson M D
Published: January 2020

Pyrolysis gas-liquid chromatography (PGLC) was used to differentiate between HeLa cell-invasive and noninvasive strains of Yersinia enterocolitica and between Sereny-positive and -negative strains. A temperature-programmed gas-liquid chromatograph, equipped with a high-resolution Carbowax 20M coated capillary column, separated the volatiles from pyrolyzed whole cells preparations and cell wall fractions. The resulting pyrolysis elution patterns (pyrograms) were divided into 313 30-s time interval areas. The time interval areas were normalized in relation to the entire pyrogram area and were evaluated by stepwise linear discriminant analysis. The results of the PGLC-statistical analyses showed good correlation in prediction of the HeLa cell invasivity test. The technique of PGLC coupled with statistical analyses is objective, in contrast to traditional methods of determining pathogenicity of Y. enterocolitica.
Enrichment of Auxotrophic Mutants in
Streptomyces griseus
Authors: Werner Rolf G. , Demain Arnold L.
Published: January 2020

A method for the isolation and enrichment of tryptophan auxotrophic mutants of the indolmycin-producing strain
Streptomyces griseus
ATCC 12648 was developed, using penicillin selection. With UV irradiation of 2.2 × 10
4
μW cm
−2
, a mutation rate to tryptophan auxotrophy of 5.6 × 10
−4
was achieved. With 300 μg ml
−1
of penicillin G, an enrichment of tryptophan auxotrophs of about 1,000-fold was attained. Approximately 40% of all survivors were tryptophan auxotrophs.
Comparison of antibody production against aflatoxin B1 in goats and rabbits
Authors: Gaur P K , El-Nakib O , Chu F S
Published: January 2020

Antibody production against aflatoxin B1 was compared in three rabbits and one goat. Titers obtained were 20 times higher in the rabbits than in the goat. The goat antiserum appeared to have a higher degree of cross-reactivity for other aflatoxins and related metabolites than did the rabbit antiserum.
Biochemical characteristics and virulence of environmental group F bacteria isolated in the United States
Authors: Seidler R J , Allen D A , Colwell R R , Joseph S W , Daily O P
Published: January 2020

Bacteria phenotypically resembling Aeromonas hydrophila, but requiring NaCl for growth, have been isolated form the New York Bight. The bacteria proved to be identical to group F organisms isolated from cases of human diarrhea in Indonesia and Bangladesh. Anaerogenic strains initiated responses in Y-1 tissue culture and rabbit ileal loop, consistent with those associated with cytotoxin- and enterotoxin-producing Aeromonas spp. strains. Separation on the basis of production of gas from glucose by group F strains was correlated with differences in mean guanine-plus-cytosine deoxyribonucleic acid base composition and in deoxyribonucleic acid relative reassociation. Both aerogenic and anaerogenic strains reassociated to a significantly greater extent with Vibrio spp. than with Aeromonas spp. and indeed should be considered a new species of the genus Vibrio.
Emulsifiers that enhance susceptibility to virus infection: increased virus penetration and reduced interferon response
Authors: Lee S H , Laltoo M , Crocker J F , Rozee K R
Published: January 2020

An emulsifier which had an environmental relationship to Reye's syndrome, when used to treated L-929 cultures, was shown to increase the rate of encephalomyocarditis virus penetration and uncoating while having no effect on the attachment of virus or on the replication of infectious ribonucleic acid. This treatment also rendered L-929 cells unable to respond normally to interferon inducers and reversed an already established interferon antiviral state. It is proposed that one or more of these actions result in the cellular enhancement of virus susceptibility.
Isolation and characterization of fecal bacteria capable of 16 alpha-dehydroxylating corticoids
Authors: Bokkenheuser V D , Winter J , O'Rourke S , Ritchie A E
Published: January 2020

For more than a decade it has been known that the fecal flora of humans and rats includes organisms capable of 16 alpha-dehydroxylating corticoids, but their identity has remained unknown. To isolate these organisms, Mueller-Hinton agar plates were seeded with fresh feces from Proteus-free rats and incubated anaerobically. On an average, 1 of every 35 colonies consisted of organisms synthesizing 16 alpha-dehydroxylase. Isolation of the individual colonies yielded two obligate anerobes, strains 144 and 146, which elaborated the enzyme. The steroid transformation could be attained by the microbial culture alone in prereduced media or in aerobic media in the presence of Escherichia coli. Although both strains were phenotypically similar to Eubacterium lentum, they differed between themselves in their enzymatic equipment.
Electron microscopy of Giardia lamblia cysts
Authors: Luchtel D L , Lawrence W P , DeWalle F B
Published: January 2020

The flagellated protozoan Giardia lamblia is a recognized public health problem. Intestinal infection can result in acute or chronic diarrhea with associated symptoms in humans. As part of a study to evaluate removal of G. lamblia cysts from drinking water by the processes of coagulation and dual-media filtration, we developed a methodology by using 5.0-microns-porosity membrane filters to evaluate the filtration efficiency. We found that recovery rates of G. lamblia cysts by membrane filtration varied depending upon the type and diameter of the membrane filter. Examination of membrane-filtered samples by scanning electron microscopy revealed flexible and flattened G. lamblia cysts on the filter surface. This feature may be responsible for the low recovery rates with certain filters and, moreover, may have implications in water treatment technology. Formation of the cyst wall is discussed. Electron micrographs of cysts apparently undergoing binary fission and cysts exhibiting a possible bacterial association are shown.
Isolation and some characteristics of anaerobic oxalate-degrading bacteria from the rumen
Authors: Dawson K A , Allison M J , Hartman P A
Published: January 2020

Obligately anaerobic oxalate-degrading bacteria were isolated from an enriched population of rumen bacteria in an oxalate-containing medium that had been depleted of other readily metabolized substrates. These organisms, which are the first reported anaerobic oxalate degraders isolated from the rumen, were gram negative, nonmotile rods. They grew in a medium containing sodium oxalate, yeast extract, cysteine, and minerals. The only substrate that supported growth was oxalate. Growth was directly related to the concentration of oxalate in the medium (1 to 111 mM), and cell yields were approximately 1.1 g (dry weight)/mol of oxalate degraded. Oxalate was stoichiometrically degraded to CO2 and formate. These anaerobes occupy a unique ecological niche and are distinct from any previously described oxalate-degrading bacteria.
Purification and Partial Characterization of an Aminopeptidase from
Lactobacillus lactis
Authors: Eggimann Bernhard , Bachmann Marc
Published: January 2020

A surface-bound aminopeptidase of
Lactobacillus lactis
cells was solubilized with lysozyme, and the extract was subjected to streptomycin sulfate precipitation, ammonium sulfate fractionation, chromatography on Sephadex G-100 and diethylaminoethyl-Sephadex A-50, and preparative polyacrylamide gel electrophoresis. The purified enzyme was homogeneous in disc electrophoretic analysis and consisted of a single polypeptide chain with a molecular weight of 78,000 to 81,000. The optimal pH and optimal temperature for enzyme activity were 6.2 to 7.2 and 47.5°C, respectively, for
l
-lysine-4-nitroanilide as the substrate. The enzyme was activated by Co
2+
and Zn
2+
ions and inhibited by Cu
2+
, Hg
2+
, and Fe
3+
ions and by the metal-complexing reagents ethylenediaminetetraacetic acid, 1,10-phenanthroline, and α,α′-dipyridyl. Higher concentrations of substrate and hydrolysis products also inhibited the activity of the enzyme. The aminopeptidase had broad substrate specificity and hydrolyzed many amino acid arylamides and many peptides with unsubstituted NH
2
-terminal amino acids.
Enumeration and characterization of standard plate count bacteria in chlorinated and raw water supplies
Authors: LeChevallier M W , Seidler R J , Evans T M
Published: January 2020

Nearly 700 standard plate count (SPC) bacteria were isolated from drinking water and untreated surface water and identified according to a scheme developed to permit the rapid, simple classification of microorganisms to genus, species, or group. Actinomycetes and Aeromonas species were the two most common groups of SPC bacteria in chlorinated distribution water. Aeromonas spp. and Enterobacter agglomerans were the two most common groups of SPC bacteria in raw water. Identification of bacterial populations before and after contact with chlorine (1 to 2 mg/liter) for 1 h revealed that chlorination selected for gram-positive bacteria. Water that contained high densities of bacteria known to be antagonistic to coliforms had low coliform isolation rates. The membrane filtration technique for enumerating SPC bacteria recovered significantly higher numbers (P < 0.001) than the standard pour plate technique.
Action of Douglas Fir Tussock Moth Larvae and Their Microflora on Dietary Terpenes
Authors: Andrews R. E. , Spence K. D.
Published: January 2020

A single type of bacterium, tentatively identified as a member of the genus
Bacillus
, was isolated from 2 of 20 midguts of Douglas fir tussock moth larvae being fed a diet of fir needles. No bacteria could be isolated from most midguts. Although spherically shaped bodies were present in the food bolus, these bodies, if microorganisms, could not be distinguished from spherical bodies associated with the plant tissue. The Douglas fir tussock moth dietary terpenes were altered during their passage through the insects, with two new terpenes being detected in the feces. One of these was identified as isoborneol. The relative significance of the insect and gut microflora with respect to terpene modification is unresolved. The well-established toxicity of terpenes may account for the near absence of common gut microflora in the insects.
Interactions Between Light and Gas Vacuoles in
Halobacterium salinarium
Strain 5: Effect of Ultraviolet Light
Authors: Simon Robert D.
Published: January 2020

The potential light shielding by intracellular gas vacuoles in
Halobacterium salinarium
strain 5 was examined by looking at the ultraviolet light inactivation curves of both wild-type cells and mutants which are defective in the production of gas vacuoles. Whereas strains defective in gas vacuole production were slightly more sensitive to ultraviolet inactivation, no significant differences in ultraviolet sensitivity were seen, indicating that these subcellular inclusion bodies are not effective as light-shielding organelles. In addition, it was shown that ultraviolet light acts as a plasmid-curing agent in
Halobacterium
.
Biochemical characterization of cholesterol-reducing Eubacterium
Authors: Mott G E , Brinkley A W , Mersinger C L
Published: January 2020

We characterized two isolates of cholesterol-reducing Eubacterium by conducting conventional biochemical tests and by testing various sterols and glycerolipids as potential growth factors. In media containing cholesterol and plasmenylethanolamine, the tests for nitrate reduction, indole production, and gelatin and starch hydrolyses were negative, and no acid was produced from any of 22 carbohydrates. Both isolates hydrolyzed esculin to esculetin, indicating beta-glycosidase activity. In addition to plasmenylethanolamine, five other lipids which contain an alkenyl ether residue supported growth of Eubacterium strain 403 in a lecithin-cholesterol base medium. Of six steroids tested, cholesterol, cholest-4-en-3-one, cholest-4-en-3 beta-ol (allocholesterol), and androst-5-en-3 beta-ol-17-one supported growth of Eubacterium strain 403. All four steroids were reduced to the 3 beta-ol, 5 beta-H products. The delta 5 steroids cholest-5-en-3 alpha-ol (epicholesterol) and 22,23-bisnor-5-cholenic acid-3-beta-ol were not reduced and did not support growth of the Eubacterium strain.
New method for large-scale growth; and concentration of the Epstein-Barr viruses
Authors: Shibley G P , Manousos M , Munch K , Zelljadt I , Fisher L , Mayyasi S , Harewood K , Stevens R , Jensen K E
Published: January 2020

Efficacious systems are described for the large-scale growth in tissue culture and concentration of infectious (P3HR-1) and transforming (B95-8) Epstein-Barr virus. Also recorded here are our updated procedures for growing stock cultures and protocols to harvest fluids containing biologically active virus which is infectious or transforming. Various methods of concentrating biologically active Epstein-Barr virus have been evaluated. Cellular debris can be removed efficiently and rapidly from culture harvest fluids by clarification through a JCF-Z continuous-flow rotor. Efficient and reliable virus concentration was achieved by molecular filtration with Millipore Pellicon cassettes, using flow rates to 10 liters/h to produce fivefold concentrates followed by pelletization in a fixed-angle rotor. Data from recent production lots showed an average infectivity titer for P3HR-1 virus of 10(4.5) early antigen units per ml (100-fold concentrate) and 10(5.7) transforming units per ml (200-fold concentrate) for B95-9 virus lots.
Detection of Lipid Degradation Products in the Water of a Reservoir During a Bloom of
Synura uvella
Authors: Jüttner Friedrich
Published: January 2020

A stripping method was used to determine the volatile compounds present in the raw water of a reservoir during a heavy bloom of
Synura uvella.
Besides numerous pollution products, a large number of previously unidentified algal excretion products were determined, including alkenes, alcohols, ketones, aldehydes, and nor-carotenoids. The approximate amounts of some important algal excretion products present in the raw water are stated. Their biosynthetic origin and possible function in the ecosystem are discussed. The offensive cod liver oil-like odor which
Synura
imparts to the raw water was traceable to
trans,cis
-deca-2,4-dienal and minor amounts of
trans,cis
-hepta-2,4-dienal.
Carrageenan from
Eucheuma striatum
(Schmitz) in Bacteriological Media
Authors: Epifanio E. C. , Veroy R. L. , Uyenco F. , Cajipe G. J. B. , Laserna E. C.
Published: January 2020

The use of carrageenan from the red alga
Eucheuma striatum
as a possible substitute for bacteriological agar was investigated. The carrageenan medium was compared with several commercially available media in terms of both their physical properties and the colony characteristics of 16 microorganisms grown on the media.
Computer-assisted method for identification of Bacillus species isolated from liquid antacids
Authors: Willemse-Collinet M F , Turnbull P C , Hospers G T , van Oppenraay A B
Published: January 2020

One hundred nineteen species of Bacillus were isolated from five heavily contaminated liquid antacids and their constituent chemicals. The 66 different reaction profiles obtained were expressed in probability figures and stored in a computer. A total of 13 Bacillus species were identified, with B. coagulans, B. licheniformis, B. subtilis, and B. polymyxa present at particularly high frequencies. The potential advantage of using a computer in the identification of aerobic sporeformers is demonstrated.
Comparing Time Course Profiles of Immediate Acetylene Reduction by Grasses and Legumes
Authors: van Berkum Peter , Sloger Charles
Published: January 2020

The time course profiles of C
2
H
2
reduction by intact
Scirpus olneyi
(bulrush),
Oryza sativa
(rice) and
Spartina alterniflora
(cordgrass) with roots in atmospheres of N
2
and 30-day-old
Glycine max
(soybean) in air were all immediately linear. This is the first report of immediately linear rates of C
2
H
2
reduction by grass roots removed from soil. The immediately linear profile of C
2
H
2
reduction by soil-free grass roots was achieved by preventing contact between the roots and air. Roots of soybeans and
S. olneyi
receiving pretreatments of O
2
above normal environmental levels for 15 min before assay exhibited a short delay in C
2
H
2
reduction. These initially nonlinear rates of C
2
H
2
reduction are attributable to transient O
2
inhibition of nitrogenase. Initial nonlinear rates of C
2
H
2
reduction were also observed with immature soybean plants and with intact plant assays of
O. sativa
and
S. olneyi
in which C
2
H
2
was injected into cylinders surrounding the plant tops. These results indicate that, apart from O
2
inhibition of nitrogenase, the diffusion of C
2
H
2
and C
2
H
4
between the nitrogen-fixing sites and the sampling ports may cause initial nonlinear rates of C
2
H
2
reduction. We conclude that in situ plant-associated nitrogenase activity should result in immediate reduction of C
2
H
2
and that linear rates are observed when the proper assay conditions are used. Our data suggest that nitrogen fixation is closely associated with the roots of
S. olneyi, O. sativa
, and
S. alterniflora
growing in salt marsh sediment.
In situ and laboratory studies of bacterial survival using a microporous membrane sandwich
Authors: Granai C , Sjogren R E
Published: January 2020

A new device and procedure for the study of bacterial survival in an aquatic environment are described. The device uses two appressed presterilized microporous membranes to expose a bacterial cell suspension to the environment at a cell concentration that closely resembles those levels found in natural aquatic ecosystems. The device has been used under laboratory controlled conditions and in situ to study and compare bacterial survival times. In laboratory studies, Escherichia coli and Streptococcus faecalis survived the longest at 12 degrees C, pH 5, and in the presence of iron or calcium ions and cysteine. Cells in mid-stationary growth phase survived longer than those in mid- or late-logarithmic phase, whereas those maintained for a year or more as stock cultures survived for shorter period of time than did recent environmental isolates. In situ studies indicate that 5% of the starting number of E. coli and S. faecalis cells may survive longer than 96 h at 16 degrees C in potable lake water, whereas survival times in polluted lake water were approximately 12 h.
Incidence of Plasmids in Marine
Vibrio
spp. Isolated from an Oil Field in the Northwestern Gulf of Mexico
Authors: Hada Howard S. , Sizemore Ronald K.
Published: January 2020

Presumptive marine
Vibrio
spp. were collected from an operational oil field and control site located in the northwestern Gulf of Mexico. Of 440 isolates analyzed for the presence of extrachromosomal deoxyribonucleic acid elements or plasmids by using the cleared lysate and agarose gel techniques, 31% showed distinct plasmid bands on agarose gels. A majority of the plasmids detected were estimated to have molecular masses of 10 × 10
6
or less. Multiple plasmids were observed in approximately half of the plasmid-containing strains. A number of isolates contained plasmids with similar banding and mobility patterns. The oil field area had noticeably more plasmid-containing strains (35 versus 23% in the control site) and a greater number of plasmids per plasmid-containing strain (an average of 2.5 plasmids, versus 1.5 in the control site). Oil field discharges might have resulted in increased plasmid incidence and diversity.
Uptake and survival of enteric viruses in the blue crab, Callinectes sapidus
Authors: Hejkal T W , Gerba C P
Published: January 2020

Uptake of poliovirus 1 by the blue crab, Callinectes sapidus, was measured to assess the likelihood of contamination by human enteric viruses. Virus was found in all parts of the crab within 2 h after the crab was placed in contaminated artificial seawater. The highest concentrations of virus were found in the hemolymph and digestive tract, but the meat also contained virus. The concentration of virus in the crabs was generally less than in the surrounding water. Changes in salinity did not substantially affect the rate of accumulation. An increase in temperature from 15 to 25 degrees C increased the rates of both uptake and removal. Poliovirus survived up to 6 days in crabs at a temperature of 15 degrees C and a salinity of 10 g/kg. When contaminated crabs were boiled, 99.9% of poliovirus 1, simian rotavirus SA11, and a natural isolate of echovirus 1 were inactivated within 8 min. These data demonstrate that viruses in crabs should not pose a serious health hazard if recommended cooking procedures are used.
Utilization of Low Concentrations of Starch by a
Flavobacterium
Species Isolated from Tap Water
Authors: van der Kooij D. , Hijnen W. A. M.
Published: January 2020

Experiments in well-cleaned glass flasks revealed that addition of starch in concentrations of 10 and 25 μg of substrate C per liter to the filtrate of slow sand filters stimulated the development of a yellow-pigmented bacterium which was identified as a
Flavobacterium
species. The isolate was able to multiply in tap water without substrates added, but addition of starch and glucose in amounts as low as 1 μg of substrate C per liter clearly enhanced growth. The substrate affinities of the
Flavobacterium
for these compounds were 3.9 μg of starch C and 3.3 μg of glucose C per liter. The results of this study indicate that microorganisms which rapidly utilize starch at a level of a few micrograms per liter commonly occur in water.
Extraction of rotavirus from human feces by treatment with lithium dodecyl sulfate
Authors: Croxson M C , Bellamy A R
Published: January 2020

A procedure has been developed for the isolation of rotavirus from human fecal specimens based on the resistance of the virus to treatment with cold 1% lithium dodecyl sulfate at neutral pH. A single detergent treatment of fecal material followed by low- and high-speed centrifugations yielded a virus suspension of sufficient purity for viral ribonucleic acid to be analyzed directly by electrophoresis on polyacrylamide gels.
Disruption of the Primary Fouling Sequence on Fiber Glass-Reinforced Plastic Submerged in the Marine Environment
Authors: Caron David A. , Sieburth John M.
Published: January 2020

Fiber glass-reinforced plastic immersed in an experimental estuarine mesocosm fouled at estimated rates of 0.5, 5.5, and 18.8 ng (wet weight) mm
−2
day
−1
over days 0 to 2, 2 to 6, and 6 to 14, respectively. Protists, dominated by diatoms, which developed between days 3 and 6 and covered 90% of the undisturbed surface in 2 weeks, were effectively removed by twice-weekly brushing of the surface to maintain an immature 3-day bacterial film which covered 12% or less of the surface and had a biomass 3 orders of magnitude smaller than surfaces with 2 weeks' unrestricted fouling. Direct brushing of the fiber glass-reinforced plastic tank walls of experimental estuarine mesocosms minimized the “wall effect” by keeping a surface that maintained a low biomass of a slowly accumulating bacterial film rather than a surface which supported the more rapid accumulation of protists which in turn may induce the settlement of invertebrates and macrophytes.
Scanning electron microscope evidence for bacterial colonization of a drinking-water distribution system
Authors: Ridgway H F , Olson B H
Published: January 2020

The surfaces of water distribution mains and suspended particulate matter from drinking water were examined by using scanning electron microscopy to investigate the nature and extent of association of microorganisms with these surfaces. In addition, X-ray energy-dispersive microanalysis was used to determine the elemental constitution of the pipe surface. Though distributed sparsely and randomly along the pipe surface, a variety of morphologically distinguishable bacteria-like structures and microcolonies were observed. The morphologies of the individual cells varied form chain-forming cocci to filamentous and prosthecate cell types. The iron-oxidizing bacterium Gallionella, recognized by its characteristic helical stalks, was observed both in water samples and attached to pipe surfaces. Attachment of some microbes to the pipe surface was apparently mediated by extracellular fibrillar appendages. Large numbers of rod-shaped bacteria were also evident adhering to the surfaces of suspended detritus or silt particles recovered from water samples by filtration. X-ray energy scans of the pipe surface revealed the presence of five major elemental constituents including silicon, phosphorous, sulfur, calcium, and iron. Smaller quantities of the elements zinc, magnesium, aluminum, potassium, and manganese were also detected. The public health significance of sessile microbial communities in drinking-water distribution systems is discussed.
Iron Bacteria in Drinking-Water Distribution Systems: Elemental Analysis of
Gallionella
Stalks, Using X-Ray Energy-Dispersive Microanalysis
Authors: Ridgway H. F. , Means E. G. , Olson B. H.
Published: January 2020

“Iron” bacteria belonging to the genus
Gallionella
were observed by scanning electron microscopy in water samples and attached to pipe surfaces in a Southern California drinking-water distribution system. The cells were recognized by their characteristic elongated helical stalks composed of numerous intertwined microfibrils. Many of the stalks were partially coated with insoluble ferric salt deposits. Stalks recovered directly from water samples were analyzed for their elemental composition by using X-ray energy-dispersive microanalysis. Silicon, aluminum, calcium, and iron were the predominant elements present in the stalks. Smaller quantities of the elements phosphorous, sulfur, chlorine, copper, and zinc were also detected. Manganese, though present in measurable quantities in the water supply, was not detected in the stalks, suggesting that this organism is unable to utilize this element as an electron donor. This represents the first such analysis of
Gallionella
stalks recovered from environmental samples without prior subculturing in artificial laboratory media.
Differential stain for mycobacteria that does not require heat
Authors: Tamási G
Published: January 2020

A stain of 0.1% toluidine blue in a 1.0% aqueous solution of triethylene glycol followed by decolorization with acid-alcohol resulted in mycobacteria retaining the stain (violet), whereas non-acid-fast bacteria were decolorized.
Clinical Isolate of
Pseudomonas aeruginosa
that Degrades Salicylate by the
ortho
Pathway
Authors: Ohta Shin , Matsumoto Hideki , Terawaki Yoshiro
Published: January 2020

A clinical isolate of
Pseudomonas aeruginosa
was found capable of utilizing salicylate by the salicylate hydroxylase and β-ketoadipate pathway.
Effects of the Herbicide Paraquat Dichloride on Bacteria of Human Origin
Authors: Peterson Ellena , Fairshter Ronald , Morrison John , Cesario Thomas
Published: January 2020

We have found the inhibitory and bactericidal concentrations of paraquat for bacteria of human origin are above levels likely to be often encountered environmentally.
Development of a Defined Medium for Growth of
Cercospora rosicola
Passerini
Authors: Norman Shirley M. , Maier Vincent P. , Echols Linda C.
Published: January 2020

A simple synthetic liquid medium containing a single amino acid, glucose, salts, trace metals, and thiamine was developed for cultivation of
Cercospora rosicola
Passerini. Thiamine was shown to be important to growth. Culture of
C. rosicola
Passerini in a chemically defined medium makes possible studies of (+)-abscisic acid biosynthesis and regulation.
Inorganic Carbon Limitation and Chemical Composition of Two Freshwater Green Microalgae
Authors: Goldman Joel C. , Graham Stephen J.
Published: January 2020

Two freshwater chlorophytes,
Chlorella vulgaris
and
Scenedesmus obliquus
, were grown in inorganic carbon-limited continuous cultures in which HCO
3
−
was the sole source of inorganic carbon. The response of the steady-state growth rate to the external total inorganic carbon concentration was reasonably well described by the Monod equation; however, the response to the internal nutrient concentration was only moderately well represented by the Droop equation when the internal carbon concentration was defined on a cellular basis. The Droop equation was totally inapplicable when total biomass (dry weight) was used to define internal carbon because the ratio of carbon to dry weight did not vary over the entire growth rate spectrum. In batch cultures, maximum growth rates were achieved at the CO
2
levels present in atmospheric air and at HCO
3
−
concentrations of 3 mM. No growth was observed at 100% CO
2
. Both nitrogen uptake and chlorophyll synthesis were tightly coupled to carbon assimilation, as indicated by the constant C/N and C/chlorophyll ratios found at all growth rates. The main influence of inorganic carbon limitation appears to be not on the chemical structure of the biomass, but rather on cell size; higher steady-state growth rates lead to bigger cells.
Production of Skatole and
para
-Cresol by a Rumen
Lactobacillus
sp
Authors: Yokoyama Melvin T. , Carlson James R.
Published: January 2020

The objective of this study was to examine the substrate specificity of several ruminal strains of a
Lactobacillus
sp. which previously was shown to produce skatole (3-methylindole) by the decarboxylation of indoleacetic acid. A total of 13 compounds were tested for decarboxylase activity. The
Lactobacillus
strains produced
p
-cresol (4-methylphenol) by the decarboxylation of
p
-hydroxyphenylacetic acid, but did not produce either
o
-cresol or
m
-cresol from the corresponding hydroxyphenylacetic acid isomers. These strains also decarboxylated 5-hydroxyindoleacetic acid to 5-hydroxyskatole and 3,4-dihydroxyphenylacetic acid to methylcatechol. Skatole and
p
-cresol were produced in a 0.5:1 ratio, when indoleacetic acid and
p
-hydroxyphenylacetic acid were combined in equimolar concentrations. Competition studies with indoleacetic acid and
p
-hydroxyphenylacetic acid suggested that two different decarboxylating enzymes are involved in the production of skatole and
p
-cresol by these strains. This is the first demonstration of both skatole production and
p
-cresol production by a single bacterium.
Deoxyribonucleic Acid Homology Among Lactic Streptococci
Authors: Jarvis Audrey W. , Jarvis Brion D. W.
Published: January 2020

A comparison was made by deoxyribonucleic acid homology of 45 strains of lactic streptococci, using two strains of
Streptococcus cremoris
and three strains of
Streptococcus lactis
as reference strains. All
S. cremoris
strains were grouped together by deoxyribonucleic acid homology.
S. lactis
strains formed a second group, except that three strains of
S. lactis
showed a high degree of homology with
S. cremoris
strains. The three
Streptococcus diacetylactis
strains could not be differentiated from
S. lactis
strains. In spite of these differences between
S. lactis
and
S. cremoris
strains, the majority of
S. cremoris, S. lactis
, and
S. diacetylactis
strains studied had at least 50% of their base sequences in common. In contrast,
Streptococcus thermophilus
strains generally showed little relationship with the other strains of lactic streptococci. The relevance of these findings to the selection of starter strains for cheese making is discussed.
Purification and Characterization of an Autolysin from
Clostridium acetobutylicum
Authors: Webster Jocelyn R. , Reid Sharon J. , Jones David T. , Woods David R.
Published: January 2020

A proteinaceous substance with antibiotic-like activity, resembling that of a bacteriocin, was isolated from an industrial-scale acetone-butanol fermentation of
Clostridium acetobutylicum
. The substance, purified by acetone precipitation, diethylaminoethyl cellulose chromatography, and polyacrylamide gel electrophoresis, was characterized as a glycoprotein with a molecular weight of 28,000. The glycoprotein was partially inactivated by certain protease enzymes. It had no effect on deoxyribonucleic acid, ribonucleic acid, or protein synthesis, and it did not result in the loss of intracellular adenosine triphosphate. The glycoprotein lysed sodium dodecyl sulfate-treated cells and cell wall preparations, and therefore it is referred to as an autolysin. The autolysin gene appeared to be chromosomal since plasmid deoxyribonucleic acid was not detected in the
C. acetobutylicum
strain.
Selective-Differential Medium for Isolation and Differentiation of
Pectinatus
from Other Brewery Microorganisms
Authors: Lee Sun Y. , Moore Sharon E. , Mabee Michael S.
Published: January 2020

An agar medium, LL-agar (lactate-lead acetate) was designed to selectively differentiate members of the genus
Pectinatus
(S. Y. Lee, M. S. Mabee, and N. O. Jangaard, Int. J. Syst. Bacteriol.
28
:582-594, 1978; S. Y. Lee, M. S. Mabee, N. O. Jangaard, and E. K. Horiuchi, J. Inst. Brew.
86
:28-30, 1980) from other brewery microorganisms. Selectivity was achieved by the use of sodium lactate as the sole source of carbon and phenylethyl alcohol as an inhibitor for aerobic gram-negative bacteria and yeast. Differentiation was established by the introduction of lead acetate into the medium, which reacted with the H
2
S liberated by
Pectinatus
and resulted in a blackening of the
Pectinatus
colonies while the other brewery organisms, when present, remained white. In combination with the Lee tube (J. E. Ogg, S. Y. Lee, and B. J. Ogg, Can. J. Microbiol.
25
:987-990, 1979) and this medium, isolation of
Pectinatus
organisms from beer samples was accomplished with convenience and simplicity.
Preparation of Uridine Diphosphate-
N
-Acetylgalactosamine from Uridine Diphosphate-
N
-Acetylglucosamine by Using Microbial Enzymes
Authors: Yamamoto Kenji , Kawai Hiroyasu , Tochikura Tatsurokurou
Published: January 2020

A method was developed for the large scale preparation of uridine diphosphate-
N
-acetylgalactosamine (UDP-GalNAc) from uridine diphosphate-
N
-acetylglucosamine (UDP-GlcNAc) by means of microbial enzymes. With
Bacillus subtilis
cell-free extract as a source of UDP-GlcNAc 4-epimerase, about 35% of the UDP-GlcNAc added was converted to UDP-GalNAc. After the residual UDP-GlcNAc was degraded to uridine triphosphate and
N
-acetylglucosamine-1-phosphate with a protamine-treated extract of bakers' yeast as a source of UDP-GlcNAc pyrophosphorylase, UDP-GalNAc was separated by anion-exchange column chromatography. The nucleotide was recovered by adsorption on charcoal and elution with ammoniacal ethanol. The final yield was about 100 μmol.
Prevention of surface mold growth on Italian dry sausage by natamycin and potassium sorbate
Authors: Holley R A
Published: January 2020

Inhibition of uncontrolled mold growth on three types of raw cured Italian dry salami was studied under commercial production conditions. Salami were dipped or sprayed with natamycin (pimaricin) or were given a combined organic acid-plus-potassium sorbate treatment. Acetic and citric acids potentiated the inhibitory effects of potassium sorbate significantly, but lactic and succinic acids showed little or no effect. Treatment of salami by dipping in 2.5% (wt/vol) potassium sorbate or 2,000 ppm (mg/liter) of pimaricin did not successfully prevent the growth of surface molds. At 10% potassium sorbate on all types of salami and at 2.5% sorbate on Casalingo salami, visual inhibition of mold growth was observed, but numbers of viable fungi on all salami types treated with 2.5% sorbate were not significantly (95% confidence) different from numbers found in the untreated controls. Pimaricin spray (2 X 1,000 ppm) was as good as or slightly better than 2.5% potassium sorbate, but greater concentrations of each were required to satisfactorily inhibit surface mold growth during the 25- to 50-day ripening period.
Extension of the model concerning linkage of genes coding for C-1 related functions in Methylobacterium organophilum
Authors: O'Connor M L
Published: January 2020

Evidence is presented which suggests that Methylobacterium organophilum contains isoenzymes of phosphoenolpyruvate carboxylase activity. Methanol-grown cells contained an acetyl coenzyme A (CoA)-insensitive activity which precipitated in a 65 to 75% of saturation ammonium sulfate fraction. Succinate-grown cells contained an acetyl-CoA-stimulated activity which precipitated in a 55 to 65% of saturation ammonium sulfate fraction. Mutants unable to grow on methanol appeared to lack acetyl-CoA-insensitive activity. This acetyl-CoA-insensitive phosphoenolpyruvate carboxylase, along with malyl-CoA lyase, is proposed to be encoded by the C-1 operon. The gene for formate dehydrogenase appeared to reside outside the operon and was not inducible by methanol. M. organophilum was unable to grow on formate, and evidence is presented suggesting that formate is unable to induce the enzymes which comprise the serine pathway for formaldehyde fixation. An expanded model for the C-1 operon is presented.
Catabolism of Substituted Benzoic Acids by
Streptomyces
Species
Authors: Sutherland John B. , Crawford Don L. , Pometto Anthony L.
Published: January 2020

Four thermotolerant actinomycetes from soil, identified as
Streptomyces albulus
321,
Streptomyces sioyaensis
P5,
Streptomyces viridosporus
T7A, and
Streptomyces
sp. V7, were grown at 45°C in media containing either benzoic acid or hydroxyl- and methoxyl-substituted benzoic acids as the principal carbon sources. Benzoic acid was converted to catechol;
p
-hydroxybenzoic, vanillic, and veratric acids were converted to protocatechuic acid; and
m
-hydroxybenzoic acid was converted to gentisic acid. Catechol, protocatechuic acid, and gentisic acid were cleaved by catechol 1,2-dioxygenase, protocatechuate 3,4-dioxygenase, and gentisate 1,2-dioxygenase, respectively. Dioxygenases appeared only in induced cultures.
m
-Hydroxybenzoic,
m
-anisic, and
p
-anisic acids were gratuitous inducers of dioxygenases in some strains. One strain converted vanillic acid to guaiacol.
Influence of white light on production of aflatoxins and anthraquinones in Aspergillus parasiticus
Authors: Bennett J W , Dunn J J , Goldsman C I
Published: January 2020

The effect of continuous light and continuous darkness on the growth of Aspergillus parasiticus and on the production of aflatoxin, averufin, versicolorin A, and versicolorin C by Aspergillus parasiticus were determined at six different temperatures with six replicates for each experiment. No growth was observed at 15 degrees C in the light, although slight growth was observed at this temperature in the dark. No aflatoxins or anthraquinones were produced in the light or dark at 35 and 40 degrees C, although growth was good at these temperatures. Differences in aflatoxins and anthraquinones for cultures grown in light and in dark were consistent at each temperature. Higher mean quantities of these secondary metabolites were produced in the light at 20 and 25 degrees C; lower mean quantities were produced in the light at 30 degrees C. The ranges of values overlapped considerably, but in all cases the differences between temperatures were significant.
Spoilage of chicken skin at 2 degrees C: electron microscopic study
Authors: Thomas C J , McMeekin T A
Published: January 2020

Microscopic techniques were used in conjunction with normal microbiological procedures to examine the development of the spoilage microflora on the skin of chicken carcasses held at 2 degrees C. Pigmented and nonpigmented psychrotrophic pseudomonads were the major spoilage bacteria isolated at all stages of storage examined. The spoilage microflora grow within a liquid film covering the skin surface, as well as in feather follicle shafts. Penetration and disruption of skin tissue were not observed even after onset of organoleptic spoilage. Bacteria were not attached to the skin by extracellular bridging substances. These data suggest a nonspecific histological-microbiological relationship between he spoilage association and the skin substrate.
Selective isolation and characteristics of Bacteriodes succinogenes from the rumen of a cow
Authors: Stewart C S , Paniagua C , Dinsdale D , Cheng K J , Garrow S H
Published: January 2020

Eleven isolates of Bacteriodes succinogenes were obtained from the rumen of a cow by an enrichment method with dewaxed cotton fibers as the selective substrate. All of the isolates degraded cotton fibers, but none formed clear zones in cellulose agar, having only a limited ability to degrade the type of cellulose powder used. One isolate, BL2, was studied in greater detail and was found to accumulate a glycogen-like polysaccharide when excess (0.5 to 1.0%) soluble carbohydrate was supplied in the nutrient medium. Although the pattern of growth and polysaccharide accumulation by strain BL2 changed during maintenance of the organism in the laboratory, the maximum amount of carbohydrate found in the cells was constant, at around 74% of the cell dry weight. The findings are discussed in relation to the methods of assessing the role of B. succinogenes in the rumen fermentation.
Microcultural Study of Bacterial Size Changes and Microcolony and Ultramicrocolony Formation by Heterotrophic Bacteria in Seawater
Authors: Torrella Francisco , Morita Richard Y.
Published: January 2020

With a microculture technique and time-lapse, phase-contrast photomicrography, it was possible to follow the division of individual cells and the development of microcolonies of bacteria in freshly collected marine water samples. A certain number of marine bacteria, upon inoculation onto a nutrient rich agar surface, displayed an increase in size as well as a high growth rate. Other bacteria were identified as very small marine bacteria (ultramicrobacteria). These had a very slow growth rate when inoculated onto a nutrient-rich agar surface. These latter cells formed very small microcolonies (ultramicrocolonies), and cell size did not increase significantly. These two types of marine heterotrophs could be described in terms of zymogenous and autochthonous bacteria, a concept used by Winogradsky for describing soil microorganisms.
Occurrence of Vibrio cholerae serotype O1 in Maryland and Louisiana estuaries
Authors: Colwell R R , Seidler R J , Kaper J , Joseph S W , Garges S , Lockman H , Maneval D , Bradford H , Roberts N , Remmers E , Huq I , Huq A
Published: January 2020

Vibrio cholerae serotype O1 has been isolated from Chesapeake Bay in Maryland and estuaries and sewers in Louisiana. The occurrence of V. cholerae O1 in the aquatic environment in the absence of human disease suggests that this organism survives and multiples in the natural environment.
Evaluation of the Total Carbonaceous Biochemical Oxygen Demand Method, Using a Compensated Recording Respirometer
Authors: Heddle John F. , Tavener Albert
Published: January 2020

The total carbonaceous biochemical oxygen demand test is described, and experimental data demonstrating its stoichiometry, precision, and accuracy are presented. The test is more reproducible and faster than the current 5-day biochemical oxygen demand test procedure, and if a respirometer is used, the effects of toxic chemicals, pH changes, and nutrient imbalances can be routinely monitored. The design principles of a multichannel compensated recording respirometer suitable for this test are described.
Induction, isolation, and characterization of aspergillus niger mutant strains producing elevated levels of beta-galactosidase
Authors: Nevalainen K M
Published: January 2020

An Aspergillus niger mutant strain, VTT-D-80144, with an improvement of three- to fourfold in the production of extracellular beta-galactosidase was isolated after mutagenesis. The production of beta-galactosidase by this mutant was unaffected by fermentor size, and the enzyme was also suitable for immobilization.
Microbial Transformation of
β
-Ionone and
β
-Methylionone
Authors: Mikami Yoichi , Fukunaga Yumiko , Arita Masatoshi , Kisaki Takuro
Published: January 2020

Aspergillus niger
JTS 191 was selected from many microorganisms tested as capable of converting ionones to other compounds having aromas. The individual transformation products from
β
-ionone were isolated and identified by comparison with synthetically derived compounds. The major products were (
R
)-4-hydroxy-
β
-ionone and (
S
)-2-hydroxy-
β
-ionone. 2-Oxo-, 4-oxo-, 3,4-dehydro-, 2,3-dehydro-4-oxo-, 3,4-dehydro-2-oxo-, (
S
)-2-acetoxy-, (
R
)-4-acetoxy-, and 5,6-epoxy-
β
-ionone and 4-(2,3,6-trimethylphenyl)-but-3-en-2-one were also identified. Analogous transformation products of
β
-methylionone also were identified. Based on gas-liquid chromatographic analysis during the fermentation, we propose two main oxidative pathways of
β
-ionone. The results of this study suggest that these transformations of
β
-ionones may be useful as tobacco-flavoring compounds.
Enhancement of varicella-zoster virus replication in cultured human embryonic lung cells treated with the pesticide carbaryl
Authors: Abrahamsen L H , Jerkofsky M
Published: January 2020

In studies designed to determine the factors responsible for control of herpesvirus replicaton in an infected cell, we examined the interaction of varicella-zoster (VZ) virus-infected human embryonic lung cells with the pesticide carbaryl. The replication of the cell-associated VZ virus was enhanced 2- to 13-fold as compared to control cultures in Sevin 4 Oil-treated cultures and in cultures treated with the pesticide's active ingredient, carbaryl. The replication of VZ virus in cultures teated with the base oil plus inert ingredients found in the pesticide formulation was not enhanced. Possible differences in cytotoxicity induced by Seven 4 Oil, pure carbaryl, or the base oil preparation were ruled out since treated and control cultures were shown to have similar numbers of viable cells when measured by trypan blue exclusion tests or by the ability of treated cells to form foci. A dose response study showed a decrease in viral enhancement in cells treated with decreasing carbaryl concentrations.
Effect of sunlight on survival of indicator bacteria in seawater
Authors: Fujioka R S , Hashimoto H H , Siwak E B , Young R H
Published: January 2020

The stability of the natural populations of fecal coliforms and fecal streptococci in raw sewage diluted 1:1,000 in seawater or phosphate-buffered water at 24 +/- 2 degrees C was markedly affected by the absence or presence of sunlight. In the absence of sunlight, these bacteria survived for days, whereas in the presence of sunlight 90% of the fecal coliforms and fecal streptococci were inactivated within 30 to 90 min and 60 to 180 min, respectively. The bactericidal effect of sunlight was shown to penetrate glass, translucent polyethylene, and at least 3.3 m of clear seawater, suggesting that the visible rather than the ultraviolet light spectrum of sunlight was primarily responsible for the observed bactericidal effect. However, these same sewage-borne bacteria were relatively resistant to the bactericidal effect of sunlight when diluted in fresh mountain stream waters. These results indicate that the presence of sunlight is a major factor controlling the survival of fecal coliforms and fecal streptococci in seawater.
Dissimilatory reduction of nitrate and nitrite in the bovine rumen: nitrous oxide production and effect of acetylene
Authors: Kaspar H F , Tiedje J M
Published: January 2020

15N tracer methods and gas chromatography coupled to an electron capture detector were used to investigate dissimilatory reduction of nitrate and nitrite by the rumen microbiota of a fistulated cow. Ammonium was the only 15N-labeled end product of quantitative significance. Only traces of nitrous oxide were detected as a product of nitrate reduction; but in experiments with nitrite, up to 0.3% of the added nitrogen accumulated as nitrous oxide, but it was not further reduced. Furthermore, when 13NO3- was incubated with rumen microbiota virtually no [13N]N2 was produced. Acetylene partially inhibited the reduction of nitrite to ammonium as well as the formation of nitrous oxide. It is suggested that in the rumen ecosystem nitrous oxide is a byproduct of dissimilatory nitrite reduction to ammonium rather than a product of denitrification and that the latter process is absent from the rumen habitat.