bluuebunny/crossref_metadata_2025 huggingface dataset:
Microcalorimetric Measurements of Glucose Metabolism by Marine Bacterium
Vibrio alginolyticus
Authors: Gordon Andrew S. , Millero Frank J. , Gerchakov Sol M.
Published: January 2020

Microcalorimetric measurements of heat production from glucose by
Vibrio alginolyticus
were made to assess the viability of calorimetry as a technique for studying the metabolism of marine bacteria at organic nutrient concentrations found in marine waters. The results show that the metabolism of glucose by this bacterium can be measured by calorimetry at submicromolar concentrations. A linear correlation between glucose concentration and total heat production was observed over a concentration range of 8 mM to 0.35 μM. It is suggested that these data indicate a constant efficiency of metabolism for this bacterium over the wide range of glucose concentrations studied.
Impact of Coal-Coking Effluent on Sediment Microbial Communities: a Multivariate Approach
Authors: Sayler Gary S. , Sherrill Timothy W. , Perkins Richard E. , Mallory Lawrence M. , Shiaris Michael P. , Pedersen Deana
Published: January 2020

The functional response to and recovery from coal-coking waste effluent was evaluated for sediment microbial communities. Twenty estimates of microbial population density, biomass, and activity were measured five times during a 15-month period. Significant effects on microbial communities were observed in response to both wastewater contamination and diversion of the wastewater. Multivariate analysis of variance and discriminant analysis indicated that accurate differentiation between uncontaminated and contaminated sediments required a minimum of nine estimates of community response. Total viable population density, ATP, alkaline phosphatase, naphthalene, and phenanthrene mineralization rates were found to be highly weighted variables in site discrimination. Lipid and glucose mineralization, nitrogen fixation, and sediment protein also contributed significantly to explaining variation among sites. Estimates of anaerobic population densities and rates of methane production contributed little to discrimination among sites in the environment examined. In general, total viable population density, ATP, and alkaline phosphatase activity were significantly depressed in contaminated sediments. However, after removal of this contamination, the previously affected sites demonstrated greater temporal variability but a closer approximation of the mean response at the control site. Naphthalene and phenanthrene mineralization did not follow the general trend and were elevated at the contaminated sites throughout the investigation. Results of the investigation supported the hypothesis that multiple functional measures of microbial community response are required to evaluate the effect of and recovery from environmental contamination. In addition, when long-term effects are evaluated, select physiological traits, i.e., polyaromatic hydrocarbon mineralization, may not reflect population and biomass estimates of community response.
Prevalence and survival of Campylobacter jejuni in unpasteurized milk
Authors: Doyle M P , Roman D J
Published: January 2020

Campylobacter jejuni was isolated from 1 to 108 (0.9%) milk samples obtained from the bulk tanks of nine grade A dairy farms and from 50 of 78 (64%) cows producing grade A milk. Survival of eight Campylobacter strains in unpasteurized milk (4 degrees C) varied greatly: the most tolerant strain showed a less than 2-log10 decrease in viable cells after 14 days, and the most sensitive strain showed a greater than 6-log10 decrease after 7 days. One strain was still recoverable 21 days after the inoculation of milk. Inactivation of the different strains corresponded with an increase in milk aerobic plate count and a decrease in milk pH; however, no absolute correlation could be made between the rates of change of these parameters and the rates of campylobacter inactivation. When held at 4 degrees C, C. jejuni was most stable in brucella broth, died most rapidly in unpasteurized milk, and was inactivated at an intermediate rate in sterile milk. Our results indicate the presence and possible persistence of C. jejuni in raw grade A milk and reaffirm the need for pasteurization of milk.
Sensitive assay, based on hydroxy fatty acids from lipopolysaccharide lipid A, for Gram-negative bacteria in sediments
Authors: Parker J H , Smith G A , Fredrickson H L , Vestal J R , White D C
Published: January 2020

Biochemical measures have provided insight into the biomass and community structure of sedimentary microbiota without the requirement of selection by growth or quantitative removal from the sediment grains. This study used the assay of the hydroxy fatty acids released from the lipid A of the lipopolysaccharide in sediments to provide an estimate of the gram-negative bacteria. The method was sensitive to picomolar amounts of hydroxy fatty acids. The recovery of lipopolysaccharide hydroxy fatty acids from organisms added to sediments was quantitative. The lipids were extracted from the sediments with single-phase chloroform-methanol extraction. The lipid-extraction residue was hydrolyzed in 1 N HCl, and the hydroxy fatty acids of the lipopolysaccharide were recovered in chloroform for analysis by gas-liquid chromatography. This method proved to be about fivefold more sensitive than the classical phenol-water or trichloroacetic acid methods when applied to marine sediments. By examination of the patterns of hydroxy fatty acids, it was also possible to help define the community structure of the sedimentary gram-negative bacteria.
Formation of ursodeoxycholic acid from chenodeoxycholic acid by a 7 beta-hydroxysteroid dehydrogenase-elaborating Eubacterium aerofaciens strain cocultured with 7 alpha-hydroxysteroid dehydrogenase-elaborating organisms
Authors: MacDonald I A , Rochon Y P , Hutchison D M , Holdeman L V
Published: January 2020

A gram-positive, anaerobic, chain-forming, rod-shaped anaerobe (isolate G20-7) was isolated from normal human feces. This organism was identified by cellular morphology as well as fermentative and biochemical data as Eubacterium aerofaciens. When isolate G20-7 was grown in the presence of Bacteroides fragilis or Escherichia coli (or another 7 alpha-hydroxysteroid dehydrogenase producer) and chenodeoxycholic acid, ursodeoxycholic acid produced. Time course curves revealed that 3 alpha-hydroxy-7-keto-5 beta-cholanoic acid produced by B. fragilis or E. coli or introduced into the medium as a pure substance was reduced by G20-7 specifically to ursodeoxycholic acid. The addition of glycine- and taurine-conjugated primary bile acids (chenodeoxycholic and cholic acids) and other bile acids to binary cultures of B. fragilis and G20-7 revealed that (i) both conjugates were hydrolyzed to give free bile acids, (ii) ursocholic acid (3 alpha, 7 beta, 12 alpha-trihydroxy-5 beta-cholanoic acid) was produced when conjugated (or free) cholic acid was the substrate, and (iii) the epimerization reaction was at least partially reversible. Corroborating these observations, an NADP-dependent 7 beta-hydroxysteroid dehydrogenase (reacting specifically with 7 beta-OH-groups) was demonstrated in cell-free preparations of isolate G20-7; production of the enzyme was optimal at between 12 and 18 h of growth. This enzyme, when measured in the oxidative direction, was active with ursodeoxycholic acid, ursocholic acid, and the taurine conjugate of ursodeoxycholic acid (but not with chenodeoxycholic, deoxycholic, or cholic acids) and displayed an optimal pH range of 9.8 to 10.2
Effects of potassium sorbate and other antibotulinal agents on germination and outgrowth of Clostridium botulinum type E spores in microcultures
Authors: Seward R A , Deibel R H , Lindsay R C
Published: January 2020

The effects of potassium sorbate, sodium hypophosphite, sodium tripolyphosphate, sodium nitrite, and linoleic acid on the germination and outgrowth of Clostridium botulinum type E spores were studied in microcultures. At pH 5.8 to 6.0 in liver veal agar, the germination rate was decreased to nearly zero with 1.0, 1.5, or 2.0% sorbate. At pH 7.0 t 7.2, these levels of sorbate afforded germination and outgrowth of abnormally shaped cells that were defective in cell division. At the high pH range, 0.5 or 1.0% hypophosphite had effects similar to those of sorbate. The use of 0.05% sodium nitrite with sorbate enhanced the lysis of outgrowing cells at pH 7.2 or lower. Emergence and elongation were inhibited by 0.05% linoleic acid with or without 1.0% sorbate at pH 7.0 to 7.2. The addition of 0.5% tripolyphosphate to media containing 1.5% sorbate at pH 7.1 prevented normal cell growth to an extent greater than with sorbate alone.
Production of Extracellular Polysaccharide by
Zoogloea ramigera
Authors: Norberg Anders B. , Enfors Sven-Olof
Published: January 2020

In batch cultures of
Zoogloea ramigera
the maximum rate of exopolysaccharide synthesis occurred in a partly growth-linked process. The exopolysaccharide was attached to the cells as a capsule. The capsules were released from the cell walls after 150 h of cultivation, which caused the fermentation broth to be highly viscous. Ultrasonication could be used to release capsular polysaccharide from the microbial cell walls. Treatment performed after 48 to 66 h of cultivation revealed exopolysaccharide concentration and apparent viscosity values in accordance with values of untreated samples withdrawn after 161 h of cultivation. The yield coefficient of exopolysaccharide on the basis of consumed glucose was in the range of 55 to 60% for batch cultivations with an initial glucose concentration of 25 g liter
−1
. An exopolysaccharide concentration of up to 38 g liter
−1
could be attained if glucose, nitrogen, and growth factors were fed into the batch culture. The oxygen consumption rate in batch fermentations reached 25 mmol of O
2
liter
−1
h
−1
during the exopolysaccharide synthesis phase and then decreased to values below 5 mmol of O
2
liter
−1
h
−1
during the release phase. The fermentation broth showed pseudoplastic flow behavior, and the polysaccharide was not degraded when growth had ceased.
Extracellular Isoamylase Produced by the Yeast
Lipomyces kononenkoae
Authors: Spencer-Martins Isabel
Published: January 2020

A strain of the starch-converting yeast
Lipomyces kononenkoae
produced, when grown on starch, a debranching enzyme that proved to be an isoamylase (glycogen 6-glucanohydrolase; E.C. 3.2.1.68). So far, only bacteria have been found to produce extracellular isoamylases. The yeast isoamylase enhanced β-amylolysis of amylopectin and glycogen and completely hydrolyzed these substrates into maltose when combined with a β-amylase but had no action on dextran or pullulan. By isopropanol precipitation and carboxymethyl cellulose chromatography,
L. kononenkoae
isoamylase was partially purified from the supernatant of cultures grown on a mineral medium with soluble starch. Optimum temperature and pH for activity of the isoamylase were 30°C and 5.6. The molecular weight was around 65,000, and the pI was at pH 4.7 to 4.8. The

K
m

(30°C, pH 5.5) for soluble starch was 9 g liter
−1
.
Nitrous Oxide Production by Organisms Other than Nitrifiers or Denitrifiers
Authors: Bleakley Bruce H. , Tiedje James M.
Published: January 2020

Heterotrophic bacteria, yeasts, fungi, plants, and animal breath were investigated as possible sources of N
2
O. Microbes found to produce N
2
O from NO
3
−
but not consume it were: (i) all of the nitrate-respiring bacteria examined, including strains of
Escherichia, Serratia, Klebsiella, Enterobacter, Erwinia
, and
Bacillus
; (ii) one of the assimilatory nitrate-reducing bacteria examined,
Azotobacter vinelandii
, but not
Azotobacter macrocytogenes
or
Acinetobacter
sp.; and (iii) some but not all of the assimilatory nitrate-reducing yeasts and fungi, including strains of
Hansenula, Rhodotorula, Aspergillus, Alternaria
, and
Fusarium
. The NO
3
−
-reducing obligate anaerobe
Clostridium
KDHS2 did not produce N
2
O. Production of N
2
O occurred only in stationary phase. The nitrate-respiring bacteria produced much more N
2
O than the other organisms, with yields of N
2
O ranging from 3 to 36% of 3.5 mM NO
3
−
. Production of N
2
O was apparently not regulated by ammonium and was not restricted to aerobic or anaerobic conditions. Plants do not appear to produce N
2
O, although N
2
O was found to arise from some damaged plant tops, probably due to microbial growth. Concentrations of N
2
O above the ambient level in the atmosphere were found in human breath and appeared to increase after a meal of high-nitrate food.
Dependence of Reproduction Rate on Pressure as a Hallmark of Deep-Sea Bacteria
Authors: Yayanos A. Aristides , Dietz Allan S. , Van Boxtel R.
Published: January 2020

Strains of bacteria in axenic culture were isolated from samples of depths between 1,957 and 10,476 m of the Pacific Ocean. All of the bacteria from this range of depths were barophilic. The pressure at which the rate of reproduction was maximal was found to be correlated with the depth of origin of the isolates.
Inexpensive Laboratory-Constructed Nephelometer
Authors: Smith Terrance L. , Witter Lloyd D.
Published: January 2020

An inexpensive, simple-to-construct nephelometer which was used to monitor the lysis of spheroplasts is described. The nephelometer is a flow-through device with a linear response to cell concentration from the lower detection limit to 8 × 10
8
cells per ml.
Radioimmunoassay for Zearalenone and Zearalanol in Human Serum: Production, Properties, and Use of Porcine Antibodies
Authors: Thouvenot Daniel , Morfin Robert F.
Published: January 2020

To produce antigens susceptible to raise antibodies for resorcylic acid lactones, the 6′-carboxymethyloxime derivatives of zearalenone and zearalanone were bound to bovine serum albumin. Pigs could be immunized by using these antigens, the best titer in antibodies being obtained with the zearalenone antigen. The porcine antibodies were specific for the resorcylic acid lactones of structural resemblance with zearalenone. This specificity made the antibodies usable for a radioimmunoassay of zearalenone and zearalanol, which may be found in human and animal sera. The range of the assay was between 0.25 and 10 ng. The limit of detection was 5 ppb (5 ng/ml) in human serum.
Potential of Lactic Streptococci to Produce Bacteriocin
Authors: Geis Arnold , Singh Jasjit , Teuber Michael
Published: January 2020

A survey was made on the bacteriocin-producing potential of lactic streptococci. Bacteriocin-like activities were isolated and partially purified from about 5% of the 280 strains investigated. The frequency of production varied from about 1% in
Streptococcus lactis
subsp.
diacetylactis
to 9 and 7.5% in
S. lactis
and
Streptococcus cremoris
, respectively. Eight strains of
S. cremoris
produced bacteriocins which, on the basis of heat stability at different pH values and inhibitory spectrum, could be divided into four types. From 54
S. lactis
strains, 5 strains produced inhibitory substances, namely, three nisin-like antibiotics and two different bacteriocins. Only 1 of 93
S. lactis
subsp.
diacetylactis
strains produced a bacteriocin which was very similar to bacteriocins of type I in
S. cremoris
. All of the bacteriocins that were partially purified by ammonium sulfate precipitation showed very limited inhibitory spectra. Most of the lactic streptococci and a few members of the genera
Clostridium, Leuconostoc
, and
Pediococcus
were inhibited. None of the bacteriocins acted on gram-negative bacteria. The bacteriocinogenic strains were also characterized on the basis of plasmid content. All strains possessed between one and nine plasmids ranging from 1 to 50 megadaltons.
Method for Establishing a Bacterial Inoculum on Corn Roots
Authors: Mendez-Castro Francisco A. , Alexander Martin
Published: January 2020

Few bacteria from the corn rhizosphere grew in media with 50 μg of mancozeb per ml. A mancozeb-resistant
Pseudomonas
strain from the rhizosphere was serially subcultured in media containing mancozeb and spectinomycin until it was resistant to 175 μg of mancozeb and 850 μg of spectinomycin per ml. The population of the pseudomonad added to soil fell to low numbers in 6 days in unamended or glucose-amended soil, but its numbers exceeded 10
5
/g for at least 12 days if the soil was supplemented with mancozeb. The numbers of this organism remained small on corn roots derived from untreated, inoculated seeds, but the population was two or more orders of magnitude greater on roots derived from mancozeb-coated seeds. The abundance of the inoculum strain on the 3-cm portion of roots nearest the stem declined markedly after about 1 week, but applying urea to the foliage reduced or prevented the decline. The numbers of the pseudomonad on segments of roots 3- to 6- and 6- to 9-cm from the stem were higher on plants derived from the mancozeb-coated seeds. Applying spectinomycin to the foliage did not promote growth of the bacterium. This method is proposed as a means to establish an introduced bacterium on plant roots.
Effect of effluent from a nitrogen fertilizer factory and a pulp mill on the distribution and abundance of Aeromonas hydrophila in Albemarle Sound, North Carolina
Authors: Hazen T C , Esch G W
Published: January 2020

The density of Aeromonas hydrophila, standard count bacteria, fecal coliform bacteria, and 18 physical and chemical parameters were measured simultaneously at six sites for 12 months in Albemarle Sound, N.C. One site was above and two sites were below the discharge plume of a Kraft pulping process paper mill. The fourth site was above and the remaining two sites were below the discharge point of a nitrogen fertilizer factory. The impact of the pulp mill on water quality was acute, whereas that of the nitrogen fertilizer factory was chronic and much more subtle. Diffusion chamber studies indicated that A. hydrophila survival is increased by pulp mill effluent and decreased by nitrogen fertilizer factory effluent. From correlation and regression analysis, A. hydrophila was found to be directly affected by phytoplankton density and, thus, indirectly by concentrations of phosphate, nitrate, and total organic carbon. These two point sources are suspect as indirect causes of red-sore disease epizootics, a disease of fish caused by A. hydrophila.
Simple apparatus for collecting estuarine sediments and suspended solids to detect solids-associated virus
Authors: Metcalf T G , Melnick J L
Published: January 2020

Laboratory trials of a new sampler for collection of estuarine sediment-associated virus resulted in a recovery effectiveness averaging 30% for two enteroviruses and rotavirus SA11. A minimal recovery potential of 54% was calculated when losses caused by virus concentration procedure inadequacies were excluded. Both sediment-associated and suspended solids-associated viruses were collected with the sampler. Recoveries of 61 and 60% poliovirus and rotavirus, respectively, were obtained from salt water-suspended, solids-associated virus. The unique advantage of the sampler for selective collection of virus-associated top layers of sediment, plus collection over extensive areas, resulted in recovery of more virus than was obtained with a commonly used dredge-type sampler.
Prototheca zopfii
Krüger Strain UMK-13 Growth on Acetate or
n
-Alkanes
Authors: Koenig David W. , Ward H. B.
Published: January 2020

A new strain of
Prototheca zopfii
Krüger was grown on acetate or on pure
n
-alkanes. A maximum acetate-supported exponential growth of 12 divisions day
−1
occurred at pH 5 and 30°C. At 25°C, growth on
n
-alkanes was almost as fast, but no growth occurred at 30°C. After 4 days at 25°C, 34 to 45% of the
n
-alkanes had been removed, whereas at 21°C and slower growth, utilization was twofold greater after 15 days. Rates of growth and utilization increased markedly after a point of sudden emulsification.
Antibiotic resistance among different species of fecal coliforms isolated from water samples
Authors: Niemi M , Sibakov M , Niemela S
Published: January 2020

The distribution of resistance to ampicillin, chloramphenicol, sulfonamides, tetracycline, and streptomycin among fecal coliforms in sewage, surface waters, and sea water was investigated. The incidence of resistant strains among isolates varied significantly among the water samples, without obvious connection with the water source or the level of pollution. The average frequency of multiple resistance was not always high in the same samples in which the overall resistance was high. The species composition varied considerably in different water samples. A significant correlation was observed between the relative frequency of Klebsiella species and the incidence of ampicillin resistance in water samples. The importance of species composition of fecal coliforms, affected by their source and by the aquatic environment, on the resistance pattern is noted.
Enhanced recovery of injured Escherichia coli by compounds that degrade hydrogen peroxide or block its formation
Authors: McDonald L C , Hackney C R , Ray B
Published: January 2020

Escherichia coli LSUFS was injured either by freezing at -10 degrees C or by heating at 57 degrees C for 12 min. Surviving cells were recovered on nonselective tryptone-glucose extract agar and selective violet red bile agar supplemented with compounds that degrade hydrogen peroxide or block its formation. Various concentrations of the following compounds were tested: sodium pyruvate, 3,3'-thiodipropionic acid, catalase, ascorbic acid, potassium permanganate, sodium thioglycolate, dimethylsulfoxide, ethoxyquin, n-propyl gallate, alpha-tocopherol sodium metabisulfite, and ferrous sulfate. Sodium pyruvate and 3,3'-thiodipropionic acid, when added to either medium, significantly (P greater than 0.01) increased recovery of injured cells. More than 90% of the heat-injured cells and 40 to 90% of the freeze-injured cells failed to grow on unsupplemented tryptone-glucose extract agar. Supplementation of violet red bile agar increased recovery, but the counts remained considerably lower than the tryptone-glucose extract agar counts. The repair detection procedure of Speck et al. (M. Speck, B. Ray, R. Read, Jr., Appl. Microbiol. 29:549-550, 1975) was greatly improved by the addition of pyruvate or 3,3'-thiodipropionic acid. However, when this improved repair detection procedure was applied to foods, pyruvate-supplemented media showed some false-positives. We therefore recommend that 3,3'-thiodipropionic acid be used to supplement media in the repair detection procedure.
Affinity Immobilization of
Escherichia coli
: Catalysis by Intact and Permeable Cells Bound to Starch
Authors: Ferenci T.
Published: January 2020

The binding of viable
Escherichia coli
cells to an immobilized ligand of a surface receptor for maltodextrins has recently been demonstrated (T. Ferenci and K. S. Lee, J. Mol. Biol.
160
:431-444, 1982). The interaction of bacteria and ligand immobilized in a chromatographic column was investigated over a wide range of applied cell densities, temperatures, eluant pH values, osmotic concentrations, and flow rates. Over 95% retention of bacteria applied to starch-Sepharose was found at cell densities up to 10
9
per ml of matrix, between pH 5.5 and 8.0, between 8 and 55°C, in the presence of 0 to 0.5 M NaCl, and at elution flow rates up to 37 column volumes per h. The catalytic capability and stability of affinity-immobilized cells was demonstrated with the cytoplasmic β-galactosidase activity of starch-bound cells. Intact immobilized bacteria exhibited slowly increasing β-galactosidase activity over several days with a plateau after 6 days. Bacteria made permeable by treatment with toluene were also bound to starch-Sepharose but showed maximum β-galactosidase activity within 1 day and exhibited no loss of enzyme activity in 8 days of continuous elution at ambient temperatures.
Adaptation of Natural Microbial Communities to Degradation of Xenobiotic Compounds: Effects of Concentration, Exposure Time, Inoculum, and Chemical Structure
Authors: Spain Jim C. , Van Veld P. A.
Published: January 2020

Adaptation of microbial communities to faster degradation of xenobiotic compounds after exposure to the compound was studied in ecocores. Radiolabeled test compounds were added to cores that contained natural water and sediment. Adaptation was detected by comparing mineralization rates or disappearance of a parent compound in preexposed and unexposed cores. Microbial communities in preexposed cores from a number of freshwater sampling sites adapted to degrade
p
-nitrophenol faster; communities from estuarine or marine sites did not show any increase in rates of degradation as a result of preexposure. Adaptation was maximal after 2 weeks and was not detectable after 6 weeks. A threshold concentration of 10 ppb (10 ng/ml) was observed; below this concentration no adaptation was detected. With concentrations of 20 to 100 ppb (20 to 100 ng/ml), the biodegradation rates in preexposed cores were much higher than the rates in control cores and were proportional to the concentration of the test compound. In addition, trifluralin, 2,4-dichlorophenoxyacetic acid, and
p
-cresol were tested to determine whether preexposure affected subsequent biodegradation. Microbial communities did not adapt to trifluralin. Adaptation to 2,4-dichlorophenoxyacetic acid was similar to adaptation to nitrophenol.
p
-Cresol was mineralized rapidly in both preexposed and unexposed communities.
Estimates of Denitrification and Nitrification in Coastal and Estuarine Sediments
Authors: Nishio Takashi , Koike Isao , Hattori Akihiko
Published: January 2020

Denitrification and nitrification in sediments of Tama Estuary and Odawa Bay, Japan, were investigated by the combined use of a continuous-flow sediment-water system and a
15
N tracer technique. At Odawa Bay, the nitrification rate was comparable to the nitrate reduction rate, and 70% of the N
2
evolved originated from nitrogenous oxides (nitrate and nitrite) which were produced by the action of nitrifying bacteria in the sediments. At Tama Estuary, the nitrate reduction rate was 11 to 17 times higher than the nitrification rate, and nitrogenous oxides derived from ammonium accounted for only 6 to 9% of the N
2
evolution by denitrification.
Cocultivation of avian orthomyxoviruses and paramyxoviruses in embryonated eggs: implications for surveillance studies
Authors: Shortridge K F , King A P
Published: January 2020

A series of avian orthomyxoviruses and paramyxoviruses were cocultivated in embryonated chicken eggs. This resulted in two categories of behavior being observed: (i) one virus was preferentially detected over the other, as shown by five out of six influenza A viruses of differing hemagglutinin subtypes being preferentially detected over paramyxoviruses, and (ii) dual isolations, for example, dual isolations of paramyxoviruses. These findings are considered in the light of results of surveillance studies of orthomyxoviruses and paramyxoviruses carried out on domestic poultry in Hong Kong.
Modified enrichment broth for isolation of Yersinia enterocolitica from nonfood sources
Authors: Weagant S D , Kaysner C A
Published: January 2020

Sorbitol-bile salts broth was modified by the addition of 0.5% peptone for the enrichment of Yersinia enterocolitica in nonfood samples. A quantitative comparison was made of the growth of Y. enterocolitica in sorbitol-bile salts broth and peptone-sorbitol-bile salts broth at 22 degrees C. Incubation for 48 h resulted in an average 7.79 log10 increase in a viable cell number for six serotypes with peptone-sorbitol-bile salts broth compared with an average 1.85 log10 increase for sorbitol-bile salts broth. Recovery from seeded seawater showed a greater than 100-fold increase in sensitivity with peptone-sorbitol-bile salts broth enrichment. Isolation of indigenous Y. enterocolitica from fresh and marine waters was also significantly enhanced.
Dynamics of Baculovirus Growth and Dispersal in
Mamestra brassicae
L. (Lepidoptera
Noctuidae
) Larval Populations Introduced into Small Cabbage Plots
Authors: Evans Hugh F. , Allaway Graham P.
Published: January 2020

The nuclear polyhedrosis virus of
Mamestra brassicae
has been studied in larval populations of the moth introduced into small plots of cabbages. Primary dispersal of virus from single foci of infected larvae resulted from enhanced movement of the larvae, which colonized new plants logarithmically. Virus growth within the host population was quantified, and infection of young larvae in the following generation was related directly to the concentration of virus produced during the primary phase. Secondary cycling of virus resulted in dispersal of inoculum from multiple foci, and a large proportion of plants were ultimately colonized by infected larvae. The dynamics of virus growth during secondary dispersal were quantified and contrasted with results from the primary phase. The significance of these results is discussed in relation to possible control of insect pests through dispersal of virus by the host insect.
Biological Control of Olive Green Mold in
Agaricus bisporus
Cultivation
Authors: Tautorus T. E. , Townsley P. M.
Published: January 2020

Successful methods to control the damaging weed mold
Chaetomium olivaceum
(olive green mold) in mushroom beds are not presently known. An attempt was made to control
C. olivaceum
by biological means. A thermophilic
Bacillus
sp. which showed dramatic activity against
C. olivaceum
on Trypticase soy agar (BBL Microbiology Systems)-0.4% yeast extract agar plates was isolated from commercial mushroom compost (phase I). When inoculated into conventional and hydroponic mushroom beds, the bacillus not only provided a significant degree of protection from
C. olivaceum
, but also increased yields of
Agaricus bisporus
.
Population Changes and Persistence of
Rhizobium phaseoli
in Soil and Rhizospheres
Authors: Robert Françoise M. , Schmidt E. L.
Published: January 2020

The impact of legume cultivation on the establishment and persistence of an inoculant strain of
Rhizobium phaseoli
and its ability to compete with a resident population of
R. phaseoli
for nodule occupancy was examined utilizing strain-specific fluorescent antibodies. The soil (Hubbard loamy sand) was inoculated homogeneously with 5 × 10
5
cells per g of soil and confined in plastic cylinders kept in field plots. Inoculated and uninoculated cylinders were either left fallow or planted to two seeds of legumes. Two hosts, navy bean (
Phaseolus vulgaris
L.) cv. Seafarer and snap bean cv. Picker, as well as a nonhost, soybean (
Glycine max
(L.) Merr.) cv. Wilkin, were used. Inoculant Viking 1 was highly stimulated in all three rhizospheres sampled at 6 (flowering), 10 (podfill), and 17 (decay) weeks and in the following spring, whereas counts in fallow soil decreased rapidly. Although the overwintering population remained highest in the vicinity of decaying host roots, Viking 1 persisted, even in fallow soil, to produce abundant nodulation of host plants the following spring. Viking 1 was an excellent competitor for nodulation sites on the roots of the hosts; it thoroughly outcompeted the resident population of
R. phaseoli
, occupying virtually 100% of the nodules under inoculated conditions in all experiments.
Pseudomonas aeruginosa
Chemotaxis Associated with Blooms of N
2
-Fixing Blue-Green Algae (Cyanobacteria)
Authors: Gallucci Kathleen K. , Paerl Hans W.
Published: January 2020

Pseudomonas aeruginosa
(Schroeter) Migula, a numerically significant bacterium found during N
2
-fixing blooms of the blue-green algae (cyanobacteria)
Anabaena
sp. in the Chowan River, North Carolina, was chemotactically attracted to amino acids when tested in a radioassay. The bacterium was labeled with
32
P
i
, and the disintegrations per minute determined by liquid scintillation counting were proportional to the number of cells accumulating in microcapillaries containing amino acids. Positive chemotaxis was observed toward all of the amino acids tested, although the degrees of response varied. Since many nitrogen-fixing blue-green algae secrete nitrogenous compounds, this attraction may be instrumental in establishing a symbiotic relationship between this bacterium and blue-green algae in freshwater.
Dependence of Clostridium botulinum gas and protease production on culture conditions
Authors: Montville T J
Published: January 2020

Reports that Clostridium botulinum toxin can sometimes be detected in the absence of indicators of overt spoilage led to a systematic study of this phenomenon in a model system. Media with various combinations of pH (5.0 to 7.0) and glucose (0.0 to 1.0%) were inoculated with vegetative cells of C. botulinum 62A and incubated anaerobically at 35 degrees C. Although growth and toxin production occurred at all pH and glucose combinations, accumulation of gas was delayed or absent in media with low pH, low glucose levels, or both. Other proteolytic C. botulinum strains gave similar results. Trypsin activation was required to detect toxin in some low pH cultures. The trypsinization requirement correlated with low proteolytic activity in the cultures. Proteolytic activity of the strains examined was 5- to 500-fold lower in botulinal assay medium than in cooked meat medium. The results indicate that the absence of gas accumulation does not preclude the presence of botulinal toxin and that proteolytic cultures grown under adverse conditions may require trypsinization for the detection of toxin.
Application of Response Surface Methodology to Evaluation of Bioconversion Experimental Conditions
Authors: Cheynier Véronique , Feinberg Max , Chararas Constantin , Ducauze Christian
Published: January 2020

Using
Candida tenuis
, a yeast isolated from the digestive tube of the larva of
Phoracantha semipunctata
(
Cerambycidae
, Coleoptera), we were able to demonstrate the bioconversion of citronellal to citronellol. Response surface methodology was used to achieve the optimization of the experimental conditions for that bioconversion process. To study the proposed second-order polynomial model, we used a central composite experimental design with multiple linear regression to estimate the model coefficients of the five selected factors believed to influence the bioconversion process. Only four were demonstrated to be predominant: the incubation pH, temperature, time, and the amount of substrate. The best reduction yields (close to 90%) were obtained with alkaline pH conditions (pH 7.5), a low temperature (25°C), a small amount of substrate (15 μl), and short incubation time (16 h). This methodology was very efficient: only 36 experiments were necessary to assess these conditions, and model adequacy was very satisfactory as the coefficient of determination was 0.9411.
Exogenous Valine Reduces Conversion of Leucine to 3-Methyl-1-Butanol in
Saccharomyces cerevisiae
Authors: Bigelis Ramunas , Weir Paul D. , Jones Richard R. M. , Umbarger H. E.
Published: January 2020

Mutant strains of the yeast
Saccharomyces cerevisiae
that require branched-chain amino acids must be supplemented with large concentrations (up to 10 mM) of these amino acids to satisfy their nutritional requirement. The utilization of one branched-chain amino acid, leucine, was examined in several
leul
strains of yeast grown aerobically in a glucose-ammonium salts minimal medium containing a limiting concentration (0.2 mM) of leucine. In this medium, the leucine requirement of the auxotrophic strains could be reduced by valine, another branched-chain amino acid. Increasing the valine concentration increased the cell yields of cultures and also reduced the levels of 3-methyl-1-butanol detected in the medium by gas chromatography. The concentration of 3-methyl-1-butanol was reduced from 122.0 to 48.9 μM when 5.0 mM valine was supplemented to limiting-leucine cultures. The amino acids isoleucine, threonine, norleucine, norvaline, α-amino-butyrate, alanine, and glycine also spared the leucine requirement of leucine auxotrophs, most likely because they resembled leucine and competed for its uptake. We propose that leucine analogs restrict the entry and degradation of leucine and thus reduce its conversion to 3-methyl-1-butanol, a major component of fusel oil.
Inhibition of Naegleria fowleri by microbial iron-chelating agents: ecological implications
Authors: Newsome A L , Wilhelm W E
Published: January 2020

Deferrioxamine B and rhodotorulic acid, iron-chelating agents of microbial origin, exerted a pronounced inhibitory effect on pathogenic Naegleria fowleri at microgram levels. This inhibition was diminished by adding iron to the chelators before incubation with Naegleria isolates. These and related microbial iron chelators occur naturally in the environment. This could be of considerable ecological significance and provides a novel hypothesis to account for the proliferation of pathogenic Naegleria spp. in certain aquatic habitats.
Method for Rapid Detection of Cyanogenic Bacteria
Authors: Castric Kathleen F. , Castric Peter A.
Published: January 2020

An agar plate method is described in which the production of hydrogen cyanide by as many as 50 microbial isolates per plate may be detected. Cyanide produced by the organisms reacts with copper(II) ethylacetoacetate and 4,4′-methylenebis-(
N,N
-dimethylaniline) in a paper disk suspended above the microbial colonies. Cell growth occurs in depressions in the agar surface, which allows separation of colonies and enhances sensitivity of hydrogen cyanide detection.
Survival of
Rhizobium phaseoli
in Coal-Based Legume Inoculants Applied to Seeds
Authors: Crawford S. L. , Berryhill D. L.
Published: January 2020

Eight coals used as carriers in legume inoculants promoted the survival of
Rhizobium phaseoli
on pinto bean seeds. Although peat was more protective, most coal-based inoculants provided >10
4
viable rhizobia per seed after 4 weeks.
Effect of Sugar Concentration in Jerusalem Artichoke Extract on
Kluyveromyces marxianus
Growth and Ethanol Production
Authors: Margaritis Argyrios , Bajpai Pratima
Published: January 2020

The effect of inulin sugars concentration on the growth and ethanol production by
Kluyveromyces marxianus
UCD (FST) 55-82 was studied. A maximum ethanol concentration of 102 g/liter was obtained from 250 g of sugars per liter initial concentration. The maximum specific growth rate varied from 0.44 h
−1
at 50 g of sugar per liter to 0.13 h
−1
at 300 g of sugar per liter, whereas the ethanol yield remained almost constant at 0.45 g of ethanol per g of sugars utilized.
Scanning electron microscopic study of uropathogen adherence to a plastic surface
Authors: Marrie T J , Costerton J W
Published: January 2020

We used a polyethylene surface to study the adherence of various urinary pathogens to a representative inert surface. The bacteria were suspended in filter-sterilized urine during this adhesion study, and differential adhesion was clearly demonstrated. Pseudomonas aeruginosa adhered most avidly and formed large microcolonies that were surrounded by an extensive amorphous matrix. Staphylococcus saprophyticus also formed microcolonies on the surface of the plastic droppers. In general, piliated strains of Escherichia coli adhered less avidly than the other organisms, but more avidly than nonpiliated strains; however, one piliated strain of E. coli adhered very poorly and behaved like a nonpiliated strain.
Starvation-Survival Processes of a Marine Vibrio
Authors: Amy Penny S. , Pauling Crellin , Morita Richard Y.
Published: January 2020

Levels of DNA, RNA, protein, ATP, glutathione, and radioactivity associated with [
35
S]methionine-labeled cellular protein were estimated at various times during the starvation-survival process of a marine psychrophilic heterotrophic
Vibrio
sp., Ant-300. Values for the macromolecules were analyzed in terms of total, viable, and respiring cells. Electron micrographs (thin sections) were made on log-phase and 5.5-week-starved cells. On a per-cell basis, the levels of protein and DNA rapidly decreased until a constant level was attained. A second method in which radioactive sulfur was used for monitoring protein demonstrated that the cellular protein level decreased for approximately 2.5 weeks and then remained constant. An initial decrease in the RNA level with starvation was noted, but with time the RNA (orcinol-positive material) level increased to 2.5 times the minimum level. After 6 weeks of starvation, 45 to 60% of the cells remained capable of respiration, as determined by iodonitrotetrazolium violet-formazan granule production. Potential respiration and endogenous respiration levels fell, with an intervening 1-week peak, until at 2 weeks no endogenous respiration could be measured; respiratory potential remained high. The cell glutathione level fell during starvation, but when the cells were starved in the presence of the appropriate amino acids, glutathione was resynthesized to its original level, beginning after 1 week of starvation. The cells used much of their stored products and became ultramicrocells during the 6-week starvation-survival process. Ant-300 underwent many physiological changes in the first week of starvation that relate to the utilization or production of ATP. After that period, a stable pattern for long-term starvation was demonstrated.
Sewage coliphages studied by electron microscopy
Authors: Ackermann H W , Nguyen T M
Published: January 2020

Sewage was enriched with 35 Escherichia coli strains, and sediments of enrichment cultures were studied in the electron microscope. They contained up to 10 varieties of morphologically different particles. T-even-type phages predominated in 14 samples. Thirteen phages were enriched, representing the families Myoviridae (seven), Styloviridae (two), Podoviridae (three), and Microviridae (one). Twelve of these corresponded to known enterobacterial phage species, namely, 121, K19, FC3-9, O1, 9266, T2, 16-19, kappa, beta 4, N4, T7, and phi X174. Cubic RNA phages and filamentous phages were not detected. Types 121 and 9266 have previously been observed only in Romania and South Africa. Identification by morphology is usually simple. Our investigative technique is qualitative and will not detect all phages present. Most enrichment strains are polyvalent, and electron microscopy is always required for phage identification. In a general way, electron microscopy seems to be the method of choice for investigation of phage geography and ecology.
Microbial Treatment of Soil to Remove Pentachlorophenol
Authors: Edgehill Richard U. , Finn Robert K.
Published: January 2020

Direct inoculation of bacteria capable of degrading pentachlorophenol (PCP) into PCP-contaminated soil was investigated as a prophylactic measure to reduce the hazards of runoffs when spills occur or when wooden poles freshly treated with PCP-containing preservatives are located near streams and lakes. In laboratory tests at 30°C, the direct addition of 10
6
PCP-utilizing
Arthrobacter
cells per g of dry soil reduced the half-life of the pesticide from 2 weeks to <1 day. Soil inoculation also was shown to be an effective way to increase the PCP disappearance rate in a test conducted in an outdoor shed.
Effects of Selected Assay Parameters on Measurement of Lignocellulose Mineralization with a Radiolabeled Substrate
Authors: Baker Katherine H.
Published: January 2020

Varying the amount of labeled substrate or the amount of leaf material resulted in significant nonlinear changes in lignocellulose mineralization, as measured with natural [
14
C]lignin-labeled lignocellulose. The use of periodic rather than continuous aeration was found not to have significant effects on measured mineralization.
Rapid Method for Detection and Quantitation of Hydroxylated Aromatic Intermediates Produced by Microorganisms
Authors: Wackett Lawrence P. , Gibson David T.
Published: January 2020

Tetrazotized
o
-dianisidine was used for quantitative measurements of the amount of 1-naphthol formed from naphthalene by fungi in liquid cultures. The reagent was also used to detect the accumulation of phenols and
cis
-dihydrodiols in fungal and bacterial colonies on solid media.
Eradication of Arizona hinshawii from artificially infected turtle eggs
Authors: Michael-Marler S , Brown M L , Siebeling R J
Published: January 2020

Turtle eggs, 24 h old, were infected with Arizona hinshawii and treated 48 h later with gentamicin sulfate (Garasol; Shering Corp., Allantown, N.J.) by pressure differential egg dip treatment to ascertain the concentration of this reagent required to eradicate this pathogen from eggs. Infected eggs treated with 1,000 or 1,500 micrograms of gentamicin per ml of dip solution eliminated detectable A. hinshawii from eggs as determined by testing shells and embryo-yolk homogenates of 12-day-old eggs and the gastrointestinal tracts, kidneys, livers and gall bladders, and yolks of 50-day-old embryos. Treated eggs produced hatchlings which did not excrete detectable A. hinshawii at 72 h or 30 days after hatching, nor was this organism recovered from the visceral organs of these hatchlings when necropsied 30 days after hatching. Bacteriological assays on infected nontreated eggs showed that greater than 70% of the eggs harbored A. hinshawii, and eggs in this group produced hatchlings which actively excreted and harbored A. hinshawii. Eggs not infected or treated also produced turtles which excreted and systemically carried A. hinshawii and Salmonella spp. though not at the same level as did the turtles produced from infected, nontreated eggs.
Oxygen Microelectrode That Is Insensitive to Medium Chemical Composition: Use in an Acid Microbial Mat Dominated by
Cyanidium caldarium
Authors: Revsbech Niels Peter , Ward David M.
Published: January 2020

A novel oxygen microelectrode with a tip diameter of 2 to 20 μm was constructed which could function satisfactorily under a variety of environmental conditions and in a variety of media, including human blood serum, citric acid at pH 2.5, moist air, and paraffin oil. Measurement of oxygen by this electrode does not require stirring of the medium. Electrodes could be made so that the 90% response time necessary to detect changes in oxygen concentration was less than 0.2 s, and response was linear with oxygen concentration. To demonstrate the performance of the electrode, oxygen and photosynthesis profiles of an acid microbial mat (pH 2.8) dominated by the eucaryotic alga
Cyanidium caldarium
were made. Photosynthetic rates as high as 95 mmol of O
2
dm
−3
h
−1
were measured within the most active 0.1-mm layer, which was ca. 0.2 mm below the surface of the microbial mat. The total photosynthetic activity was 47 mmol of O
2
m
−2
h
−1
. Vertical profiles of photosynthesis at different light intensities showed that the microalgae within the mat were not photoinhibited at bright sunlight (2,090 μEinsteins m
−2
s
−1
).
Kinetics of Virus Inactivation by Ammonia
Authors: Cramer W. N. , Burge W. D. , Kawata K.
Published: January 2020

Ammonia has been shown to be virucidal in sludge and NH
4
Cl solutions, although the rates at which viruses are inactivated have not been thoroughly studied. In the present studies, the kinetics of the poliovirus type 1 (strain CHAT) and bacteriophage f2 inactivation were examined in such a way that the effects of OH
−
and NH
4
+
could be separated from those of NH
3
. Purified virus stocks were placed into solutions of NH
4
Cl and control solutions containing an equivalent concentration of NaCl and incubated at 20°C. The percentage of virus surviving was calculated, and the kinetics were evaluated by constructing semilogarithmic plots of data. At all pH values and NH
3
concentrations studied, the kinetics of the inactivation of both viruses were pseudo-first order. OH
−
had no measurable effect on the viruses, whereas the effects of NH
4
+
and Na
+
were similar. A dose-response relationship between NH
3
and the viruses was also found. Bacteriophage f2 was approximately 4.5 times more resistant to the effects of NH
3
than was poliovirus.