bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical taxonomy and ecology of petroleum-degrading bacteria
Authors: Austin B , Calomiris J J , Walker J D , Colwell R R
Published: January 2020

A total of 99 strains of petroleum-degrading bacteria isolated from Chesapeake Bay water and sediment were identified by using numerical taxonomy procedures. The isolates, together with 33 reference cultures, were examined for 48 biochemical, cultural, morphological, and physiological characters. The data were analyzed by computer, using both the simple matching and the Jaccard coefficients. Clustering was achieved by the unweighted average linkage method. From the sorted similarity matrix and dendrogram, 14 phenetic groups, comprising 85 of the petroleum-degrading bacteria, were defined at the 80 to 85% similarity level. These groups were identified as actinomycetes (mycelial forms, four clusters), coryneforms, Enterobacteriaceae, Klebsiella aerogenes, Micrococcus spp. (two clusters), Nocardia species (two clusters), Pseudomonas spp. (two clusters), and Sphaerotilus natans. It is concluded that the degradation of petroleum is accomplished by a diverse range of bacterial taxa, some of which were isolated only at given sampling stations and, more specifically, from sediment collected at a given station.
Epoxidation of aldrin to exo-dieldrin by soil bacteria
Authors: Ferguson J A , Korte F
Published: January 2020

Twenty-two strains of soil bacteria, including representatives of the genera Bacillus, Micromonospora, Mycobacterium, Nocardia, Streptomyces, Thermoactinomyces, and Pseudomonas and 10 unidentified gram-negative, motile, rod-shaped bacteria, were shown to degrade aldrin to its epoxide dieldrin. In every case, the exo-stereoisomer of dieldrin was produced exclusively.
Degradation of lindane by cell-free preparations of Clostridium sphenoides
Authors: Heritage A D , MacRae I C
Published: January 2020

Cell-free preparation of Clostridium sphenoides degraded the insecticide lindane, the gamma-isomer of 1,2,3,4,5,6-hexachlorocyclohexane, to the gamma-isomer of 3,4,5,6-tetrachloro-1-cyclohexene. The activity appeared to be associated with the membrane fraction and required reduced glutathione. The tetrachlorocy-clohexene intermediate was further metabolized by the membrane fraction to unknown substances.
Fungal transformation of 2,4-dinitrotoluene and 2,4,6-trinitrotoluene
Authors: Parrish F W
Published: January 2020

Screening of 190 fungi representing 98 genera showed that the ability to transform 2,4,6-trinitrotoluene was common, whereas transformation of 2,4-dinitrotoluene was rare.
Dialysis technique for containment of microbial populations inoculated into food systems
Authors: Willardsen R R , Busta F F , Allen C E
Published: January 2020

A technique utilizing dialysis tubing was developed for the containment of microbial populations introduced into a food system. The entrapment of the inoculum was accomplished while reducing interference with interactions between the sample and the surrounding environment.
Rate of microbial transformation of polycyclic aromatic hydrocarbons: a chromatographic quantification procedure
Authors: Herbes S E , Schwall L R , Williams G A
Published: January 2020

A chromatographic procedure has been developed for isolating and quantifying microbial transformation products of 14C-labeled polycyclic aromatic hydrocarbons. Transformation rates of naphthalene, anthracene, benz(a)anthracene, and benz(a)pyrene by a mixed bacterial population have been measured. With this procedure, extremely slow or incomplete transformations may be quantified that would not be detectable by previously used techniques.
Microscopic Counting and Adenosine 5′-Triphosphate Measurement in Determining Microbial Growth in Soils
Authors: Paul E. A. , Johnson R. L.
Published: January 2020

A microscopic technique utilizing dispersion of fungal hyphae in a Waring blender, filtration through membrane filters (Nucleopore Corp.), and counting on a fluorescence microscope was developed for counting fungal hyphal biomass. Nonfluorescent staining techniques of the soil-filter preparation did not give quantitative recoveries. Water-soluble aniline blue, which binds to the β-1,3-glucans of the fungal cell wall, made visualization of the hyphae by fluorescence possible. A range of fungi added to soil were quantitatively recovered. Adenosine 5′-triphosphate (ATP) was extracted from soil by lysis of the organisms with CHCl
3
in NaHCO
3
, which prevented adsorption of the organic phosphorus to the soil colloids. Centrifugation and removal of CHCl
3
was followed by dilution with pH 7.8 tris(hydroxymethyl)aminomethane buffer. ATP concentrations were measured by using the luciferase-luciferin light reaction. Since NaHCO
3
interfered to some extent with this reaction, the standards were made up in equivalent mixtures of tris(hydroxymethyl)aminomethane buffer and NaHCO
3
. Recovery of ATP was rapid and quantitative in a range of soils. Measurement of the ATP and bacterial and fungal numbers in an incubated soil showed that fungal and bacterial population increases were delayed by phosphorus deficiency. Microbial populations were not affected at a later date. The ATP content of the soil system was reduced by phosphorus deficiency throughout the incubation period. This indicated that ATP could be altered without major changes in the microbial populations.
Increased recovery of salmonellae from environmental samples enriched with buffered peptone water
Authors: Thomason B M , Dodd D J , Cherry W B
Published: January 2020

The incidence and persistence of salmonellae in weather pools on the top of Stone Mountain were investigated with lactose and buffered peptone water used as pre-enrichment broths. A total of 162 samples were collected from 16 weather pools over a 3-month period. The use of buffered peptone water increased the recovery of salmonellae by approximately 25%. The combined use of direct enrichment in tetrathionate broth containing brilliant green dye and pre-enrichment in buffered peptone water followed by enrichment in tetrathionate broth made it possible to detect all 37 of the contaminated samples. All of the isolates were Salmonella bareilly, the only serotype recovered in a previous study. All but one of the isolations were made from moist or wet samples. S. bareilly was isolated from rabbit dung and litter collected near the weather pools, but attempts to trap rabbits for study were unsuccessful. Random samples taken along a side of the mountain yielded S. bareilly in weather pools within the upper third of the mountain; below this level, S. weslaco and S. memphis were recovered, but not S. bareilly.
Simplified 48-hour IMVic test: an agar plate method
Authors: Powers E M , Latt T G
Published: January 2020

An agar plate method was developed for the performance of the IMVic (indole, methyl red, Voges-Proskauer, and citrate) tests in lieu of the conventional tubed liquid media. By modifying the composition of the media and adding agar, a single "X"-compartmented petri dish was prepared containing all four IMVic test media. Ease of performance and simplification of the test were achieved by inoculating all four media simultaneously from a single colony (single inoculum) on eosin-methylene blue agar. Tests with 87 cultures, representing 7 genera in the family Enterobacteriaceae, were completed with typical (correct) IMVic patterns for all cultures within 48 h. Parallel tests with conventional media showed that the agar plate method was superior, more sensitive, faster, and simpler to perform, and less time was required to identify Escherichia coli by 72 h.
Effects of enrichment media and incubation conditions on isolating salmonellae from ground-meat filtrate
Authors: Kafel S , Bryan F L
Published: January 2020

Forty-eight combinations of enrichment media, secondary enrichment, incubation times and temperatures, and atmospheres were examined for their efficacy in recovering different serovars of Salmonella that had been inoculated into ground-meat extract. Variations included three selective-enrichment media, two (37 and 43 degrees C) incubation temperatures, two (24 and 48 h) incubation times, two (aerobic and anaerobic) incubation atmospheres, and secondary enrichment to two of the selective-enrichment media. The ratio of Salmonella to other microorganisms was 10: greater than 1,000,000. One-hundred and twenty-four tests were conducted for each enrichment under each condition of incubation. None of the methods recovered Salmonella in more than 60% of the trials. Salmonella typhimurium was recovered most frequently of the serovars tested; S. abortusovis was recovered least frequently. There was considerable variation in the results obtained by the different methods, but there was a statistically significant advantage in the 43 degrees C incubation temperature. Secondary enrichment in tetrathionate broth showed a statistically significant advantage over secondary enrichment in selenite broth. Secondary enrichment into a different medium from the primary enrichment also was advantageous.
Exocellular mucopolysaccharide closely related to bacterial floc formation
Authors: Tago Y , Aida K
Published: January 2020

A bacterium isolated from activated sludge formed a visible floc and also produced an exoenzyme that could bring about deflocculation. Scanning electron microscopic examination revealed that the cells were embedded in a film mesh in the floc, which disappeared after treatment with the deflocculating enzyme. Polysaccharides isolated from the floc were fractionated into three fractions by diethylaminoethyl-Sephadex A-25 column chromatography, whereas those from the free cells were fractionated into only two fractions. The missing fraction was a mucopolysaccharide composed of glucosamine, glucose, mannose, galactose, and rhamnose and was hydrolyzed to oligosaccharides by the deflocculating enzyme. The other two fractions were resistant to the enzyme. These results show that the mesh structure of the floc is dependent on a mucopolysaccharide hydrolyzed by the deflocculating enzyme.
Synchronization of
Escherichia coli
by Zonal Centrifugation
Authors: Kung Fang-Chien , Glaser Donald A.
Published: January 2020

A zonal centrifugation technique that can select the smallest newborn cells in an exponentially growing culture of
Escherichia coli
B/r is described.
Arenavirus Concentration by Molecular Filtration
Authors: Gangemi J. D. , Connell E. V. , Mahlandt B. G. , Eddy G. A.
Published: January 2020

Liter volumes of a human arenavirus pathogen (Machupo) and a nonpathogen (Tacaribe) were concentrated 30 to 100 times in less than 90 min without significant loss of particle infectivity.
Bacterial flora of the sea urchin Echinus esculentus
Authors: Unkles S E
Published: January 2020

A total of 85 isolates of mesophilic, aerobic, heterotrophic bacteria were isolated from the gut, peristomial membrane, and coelomic fluid from specimens of the sea urchin Echinus esculentus from the Clyde Sea area of Scotland. These isolates were compared with 26 isolates from sand and seawater in the same locality. Overall, strains of Pseudomonas and Vibrio predominated. Gut (with an average bacterial viable count of 2 X 10(7) per 3-cm section) and coelomic fluid (which was often sterile and rarely had more than 40 bacteria per ml) had similar distributions of genera, with Vibrio predominating and Pseudomonas and Aeromonas next in abundance. In contrast, the flora of the peristomial membrane (with an average count of detachable bacteria of 2.5 X 10(5) per membrane) resembled that of sand/seawater in having Pseudomonas predominating, gram-positive forms or Vibrio next in abundance, and smaller numbers of Aeromonas, Flavobacterium, Acinetobacter, and Moraxella.
Metabolism of naphthalene by Cunninghamella elegans
Authors: Cerniglia C E , Gibson D T
Published: January 2020

Cunninghamella elegans grown on Sabouraud dextrose broth in the presence of naphthalene produced six metabolites. Each product was isolated and identified by conventional chemical techniques. The major metabolites were 1-naphthol (67.9%) and 4-hydroxy-1-tetralone (16.7%). Minor products isolated were 1,4-naphthoquinone (2.8%), 1,2-naphthoquinone (0.2%), 2-naphthol (6.3%), and trans-1,2-dihydroxy-1,2-dihydronaphthalene (5.3%). C. elegans oxidized both 1-naphthol and 1,4-naphthoquinone to 4-hydroxy-1-tetralone. The results suggest that C. elegans oxidizes naphthalene by a sequence of reactions similar to those reported for the mammalian metabolism of this hydrocarbon.
Filtration removal of endotoxin (pyrogens) in solution in different states of aggregation
Authors: Sweadner K J , Forte M , Nelsen L L
Published: January 2020

Bacterial lipopolysaccharides are recognized as the major cause of pyrogenic reactions from parenteral solutions. Molecular filtration was used to remove these pyrogenic molecules (endotoxins) from contaminated parenteral solutions. Because bacterial lipopolysaccharides can exist in different states of aggregation, depending on the composition of the solution they are suspended in, the full range of possible states of aggregation was examined by using filters with a wide range of pore sizes. Filters of different pore sizes retained endotoxin lipopolysaccharide presumed to be in the vesicle form, the micelle form, or the detergent-solubilized form in aqueous solutions. Endotoxins (pyrogens) were successfully removed from artificially contaminated solutions of concentrated antibiotics by using filters of 10,000-nominal-molecular-weight limit.
Requirement of heme for growth of Bacteroides fragilis
Authors: Sperry J F , Appleman M D , Wilkins T D
Published: January 2020

Heme or protoporphyrin IX was required for growth of Bacteroides fragilis in a defined medium. The amount of heme necessary for half-maximal growth was 2 to 10 ng/ml (3.8 to 15 pmol/ml) among the Bacteroides species and strains tested. The growth rate, metabolic products from glucose fermentation, and cell yields were affected by the concentration of heme in the medium and by the length of time the culture was incubated. When heme was growth limiting (4 ng/ml), growth rates decreased by 50%, cultures started producing lactic and fumaric acids, and the cell yields declined. The cell yield for B. fragilis (ATCC 25285) at 24 h in medium containing 6.5 microgram of heme per ml was 69 g (dry weight) of cells per mol of glucose compared to 16 g (dry weight) of cells per mol of glucose with 4 ng of heme per ml. B. fragilis was unable to grow in defined medium when a porphyrin precursor, delta-aminolevulenic acid or porphobilinogen, was added in place of heme.
Production, purification, and characterization of alpha-amylase from Thermomonospora curvata
Authors: Glymph J L , Stutzenberger F J
Published: January 2020

Thermomonospora curvata produces an extracellular alpha-amylase. Maximal amylase production by cultures in a starch-mineral salts medium occurred at pH 7.5 and 53 degrees C. The crude enzyme was unstable to heating (65 degrees C) at pH 4 to 6, and was activated when heated at pH 8. The enzyme was purified 66-fold with a 9% yield and appeared homogeneous on discontinuous gel electrophoresis. The pH and temperature optima for activity of the purified enzyme were 5.5 to 6.0 and 65 degrees C. The molecular weight was calculated to be 62,000. The Km for starch was 0.39 mg/ml. The amylolytic pattern consisted of a mixture of maltotetraose and maltopentaose.
Nitrate Reduction to Nitrite, a Possible Source of Nitrite for Growth of Nitrite-Oxidizing Bacteria
Authors: Belser L. W.
Published: January 2020

Growth yields and other parameters characterizing the kinetics of growth of nitrite-oxidizing bacteria are presented. These parameters were measured during laboratory enrichments of soil samples with added nitrite. They were then used to reanalyze data for nitrite oxidizer growth in a previously reported field study (M. G. Volz, L. W. Belser, M. S. Ardakani, and A. D. McLaren, J. Environ. Qual. 4:179-182, 1975), where nitrate, but not nitrite or ammonium, was added. In that report, analysis of the field data indicated that in unsaturated soils, the reduction of nitrate to nitrite may be a significant source of nitrite for the growth of nitrite oxidizers. A yield of 1.23 × 10
4
cells per μg of N was determined to be most appropriate for application to the field. It was determined that if nitrite came only from mineralized organic nitrogen via ammonium oxidation, 35 to 90% of the organic nitrogen would have had to have been mineralized to produce the growth observed. However, it is estimated that only about 2% of the organic nitrogen could have been mineralized during the growth period. Thus, it appears that another source of nitrite is required, the most likely being the reduction of nitrate to nitrite coupled to the oxidation of organic matter.
Bile Salt Degradation by Nonfermentative Clostridia
Authors: Mahony David E. , Meier C. Elizabeth , Macdonald Ian A. , Holdeman Lillian V.
Published: January 2020

Eight strains of nonfermentative clostridia were characterized on the basis of their intracellular nicotine adenine dinucleotide- and nicotinamide adenine dinucleotide phosphate-dependent hydroxysteroid dehydrogenase (HSDH) content, ability to deconjugate taurocholate, growth characteristics, and metabolic products, including utilization of lactate and pyruvate. Two cultures of
Clostridium sporosphaeroides
(representing one strain obtained from two different sources), one strain of
Clostridium irregularis
, four strains of an unnamed species (
Clostridium
group SPH-1), and one strain of an unnamed species (
Clostridium
group P) were studied. Both cultures of
C. sporosphaeroides
contained low amounts of 7α-HSDH;
C. irregularis
contained only a low amount of 3α-HSDH. All four strains of
Clostridium
SPH-1 contained both 12α- and 7α-HSDH in the ratio of approximately 10:1. The strain of
Clostridium
group P contained only 12α-HSDH and was devoid of any other bile salt oxidoreductases. The enzyme preparation from
Clostridium
group P was useful in spectrophotometric quantitative studies of 12α-OH groups. Correlation of bile salt degradative activities with other phenotypic tests for characterization of and differentiation among such organisms is discussed.
Application of the rapid lysine decarboxylase test for early isolation and detection of salmonellae in sewage and other wastewaters
Authors: Phirke P M
Published: January 2020

A method for early isolation and detection of salmonellae in sewage and other wastewaters by using the rapid lysine decarboxylase test as a single biochemical reaction for screening the suspected Salmonella colonies is described. By this method, Salmonella isolation and identification can be completed within 2 to 3 days in contrast to the 5 to 7 days required for the conventional method.
Retention of bacteria in liquid films at agar surfaces
Authors: Thomas C J , McMeekin T A , Balis C
Published: January 2020

The number of bacteria retained by agar dipslides immersed in bacterial suspensions was dependent solely on suspension population density and was unaffected by the nutrient status of the agar surface or liquid, disturbance of the liquid, or bacterial motility and chemotaxis.
Aerobic Plate Count and
Escherichia coli
Determination on Frozen Ground-Beef Patties
Authors: Goepfert J. M.
Published: January 2020

The aerobic plate count and
Escherichia coli
content of 604 samples of frozen ground-beef patties is reported. The results are discussed with regard to existing and proposed microbiological standards for raw meats.
Rapid identification and quantitation of small numbers of microorganisms by a chemiluminescent immunoreaction
Authors: Halmann M , Velan B , Sery T
Published: January 2020

A method (patent pending) for rapidly identifying and quantitating small numbers of microorganisms was developed based on the specific immunoreaction of microorganisms with homologous antibodies linked by conjugation to peroxidase. The high sensitivity of the method is due to the use of a chemiluminescent reaction for the determination of the enzyme. The reaction was performed on Alcar supports with low nonspecific adsorption. The very low noise achieved permitted the detection of as few as 30 to 300 bacterial cells.
Alkaline phosphatase activity of rumen bacteria
Authors: Cheng K J , Costerton J W
Published: January 2020

Of the 54 strains of rumen bacteria examined for alkaline phosphatase (APase) production, 9 of 33 gram-negative strains and none of 21 gram-positive strains produced the enzyme. The APase of the cells of the three strains of Bacteroides ruminicola that produced significant amounts of the enzyme was located in the periplasmic area of the cell envelope, whereas the enzyme was located in the strains of Selenomonas ruminantium and Succinivibrio dextrinosolvens was associated with the outer membrane. The localization of APase production in the cells of natural populations of rumen bacteria from hay-fed sheep was accomplished by reaction product deposition, and both the proportion of APase-producing bacteria and the location of the enzyme in the cell envelope of the producing cells could be determined. We suggest that this procedure is useful in detecting shifts in the bacterial population and the release of cell-bound APase that accompany feedlot bloat and other sequelae of dietary manipulation in ruminants.
Electron microscopy of Mycoplasma pneumoniae microcolonies grown on solid surfaces
Authors: Kim C K , Pfister R M , Somerson N L
Published: January 2020

Mycoplasma pneumoniae sprain CL-8 was studied by using various surfaces for adherence and growth. Cells grown on Epon 812, Formvar, carbon, and glass were of similar morphology. Thin Epon pieces were good material for culturing the organisms and examining thin-sectioned microcolonies by transmission electron microscopy.
(14C)acetate assimilation by a type I obligate methylotroph, Methylococcus capsulatus
Authors: Patel R N , Hoare S L , Hoare D S , Taylor B F
Published: January 2020

Methanol and formate oxidation supported the assimilation of [14C]acetate by cell suspensions of Methylococcus capsulatus; oxidation of other primary alcohols, except ethanol, did not. The extent of [1-14C]acetate assimilation supported by methanol oxidation was decreased in the presence of primary alcohols, except ethanol. Potassium cyanide (0.33 mM) completely inhibited the oxidation of formate and its stimulation of [1-14C]acetate assimilation. The amount of [1-14C]acetate assimilation supported by methanol oxidation was significantly inhibited by cyanide.
Histidine production by a regulatory mutant of Streptomyces coelicolor
Authors: Derkos-Sojak V , Korajlija J , Delíc V
Published: January 2020

Streptomyces coelicolor mutant RF-59, isolated as a revertant of a histidine auxotroph after mutagenic treatment with N-methylN'-nitro-N-nitrosoguanidine, was found to accumulate L-histidine. The mutant was sensitive to 2-thiazo-lealanine and L-2,4-diaminobutyric acid and partially sensitive to alpha-methylhistidine but resistant to 1,2,4-triazolealanine, indicating that repression of the histidine operon was modified in the mutant. Culture conditions were investigated, and optimal media for L-histidine production were developed, resulting in L-histidine accumulation of 2.1 to 3.5 g/liter.
Microbial metabolic activity in soil as measured by dehydrogenase determinations
Authors: Casida L E
Published: January 2020

The dehydrogenase technique for measuring the metabolic activity of microorganisms in soil was modified to use a 6-h, 37 degrees C incubation with either glucose of yeast extract as the electron-donating substrate. The rate of formazan production remained constant during this time interval, and cellular multiplication apparently did not occur. The technique was used to follow changes in the overall metabolic activities of microorganisms in soil undergoing incubation with a limiting concentration of added nutrient. The sequence of events was similar to that obtained by using the Warburg respirometer to measure O2 consumption. However, the major peaks of activity occurred earlier with the respirometer. This possibly is due to the lack of atmospheric CO2 during the O2 consumption measurements.
Effects of long-term treatment with acetylene on nitrogen-fixing microorganisms
Authors: David K A , Fay P
Published: January 2020

Long periods of experimental incubation with acetylene led to a multifold enhancement of acetylene-reducing activity in Anabaena cylindrica, Anabaenopsis circularis, Rhodospirillum rubrum, and Azotobacter vinelandii. Rates of acetylene reduction showed a gradual increase and reached a peak after 2 to 6 h of continuous incubation under acetylene. Thereafter, enzyme activity rapidly declined. A similar enhancement of ethylene production was observed when pretreatment with acetylene was interrupted periodically by a brief exposure to ambient (or oxygen-free) atmosphere without acetylene although the decline of acetylene-reducing activity was less rapid. Pretreatment with acetylene depressed photosynthetic 14CO2 fixation and 15N2 incorporation in Anabaena cylindrica. It is concluded that assessments based on long-term experimental incubation with acetylene may grossly overestimate the actual quantities of fixed nitrogen in the field.
Enhancement of isoleucine hydroxamate-mediated growth inhibition and improvement of isoleucine-producing strains of Serratia marcescens
Authors: Kisumi M , Komatsubara S , Chibata I
Published: January 2020

Growth inhibition by isoleucine hydroxamate in Serratia marcescens was significantly enhanced by adding valine plus leucine and by using glycerol as the carbon source. Isoleucine hydroxamate-resistant mutants were isolated under conditions in which growth inhibition was enhanced. One of the mutants, strain GIHVLr2179, lacked both feedback inhibition and repression of threonine deaminase. An alpha-aminobutyric acid-resistant mutant derived from strain GIHVLr2179, strain GIHVLAr2795, produced 12 mg of isoleucine per ml in the medium containing glucose and urea as carbon and nitrogen sources (a twofold increase over prior reports). This strain had increased activities of threonine deaminase, acetohydroxy acid synthase, aspartokinase, and homoserine dehydrogenase.
Isolation and identification of pathogenic Naegleria from Florida lakes
Authors: Wellings F M , Amuso P T , Chang S L , Lewis A L
Published: January 2020

Five cases of primary amoebic meningoencephalitis associated with swimming in freshwater lakes have been recorded in Florida over the past 14 years. The present study demonstrated that pathogenic Naegleria, the causative agent, is relatively widespread. Twelve of 26 lakes sampled only once yielded the amoeba. Populations in three of five lakes sampled routinely reached levels of one amoeba per 25 ml of water tested during the hot summer months. Overwintering in freshwater lake bottom sediments was demonstrated, showing that thermal-discharge pollution of waters plays a miniscule, if any, role in the maintenance of pathogenic Naegleria in nature in this semitropical area.
Virus production with a newly developed microcarrier system
Authors: Giard D J , Thilly W G , Wang D I , Levine D W
Published: January 2020

Primary cell cultures as well as established lines have been grown on a recently developed microcarrier configuration that overcomes the problem of toxicity attendant on earlier developments in this technology. Virus yields from these cells propagated on the new microcarriers have been measured. Microcarrier-grown cells, when compared to roller-bottle-grown cells, gave virus yields on a per-cell basis that varied from slightly greater with the Sindbis virus-Chinese hamster ovary cells and polio-WI-38 combinations to approximately one-third with Moloney murine leukemia virus-Cl-1 mouse cells and vesicular stomatitis virus-chicken embryo fibroblasts. Yields ranged from 8.0 X 10(7) to 3.6 X 10(8) cells per 100-ml microcarrier culture and from 3.7 X 10(7) to 4.1 X 20(8) cells per roller-bottle culture. Secondary chicken embryo fibroblast yields were approximately four times as great in microcarrier cultures as in standard roller-bottle cultures, per unit volume of medium consumed. In spite of the reduced virus yields per cell seen in some instances, the greater cellular productivity of microcarrier cultures appears to hold great promise for large-scale virus production. Optimizing microcarrier conditions for specific cell-virus systems should result in improved yields.
Temporal study of the staphylococci and micrococci of normal infant skin
Authors: Carr D L , Kloos W E
Published: January 2020

Staphylococcus and Micrococcus populations were collected from the healthy skin of 10 infant subjects. Infants were sampled from 1 day to 32 weeks of age. Species were characterized by approximately 30 different morphological, physiological, and biochemical characters. Staphylococci were the predominant inhabitants of normal skin, whereas micrococci were found only occasionally in this environment. Staphylococcus epidermidid, S. haemolyticus, and S. hominis were the predominant and persistent staphylococci. These species constituted a high percentage of the total aerobic bacterial flora of infant skin. Micrococcus luteus and M. kristinae were the prevalent micrococci found on infant skin. Only limited correlation between Staphyloccus and Micrococcus populations and infant age or body area sampled was indicated by this study.
Temperature effects on bacterial movement
Authors: Schneider W R , Doetsch R N
Published: January 2020

Details are presented for the construction of a simple precision temperature-controlled chamber for investigating bacterial motile behavior. Independent of original incubation temperature, all species of motile bacteria observed showed a five- to sevenfold increase in average translational velocity (micrometers per second) as the environment temperature was incremented over the range from 10 to 50 degrees C. Temperature jumps downward produced transient tumbling or reciprocal behavior responses, depending on the mode of flagellar distribution, in all species examined. Upward temperature jumps induced accelerated velocities without tumbling or reversal. A partial capacity adaptation to temperature was noted, in that the greatest average translational velocity at any given observation temperature occurred when the organisms were grown at temperatures less than the optimum.
Statistical analysis and quality control in radioimmunoassays for staphylococcal enterotoxins A, B, and C
Authors: Orth D S
Published: January 2020

The objective of these studies was to set up a reliable radioimmunoassay (RIA) for staphylococcal enterotoxins A, B, and C (SEA, SEB, and SEC) in a food system. Significant differences (95% confidence limits) were obtained between the 0- and 1-ng/ml enterotoxin standards, so the sensitivity of the RIAs was 1 ng/ml. Polystyrene tubes coated with anti-SEB and stored at 4 degrees C were unstable. The percentage of iodinated SEB bound to these tubes decreased at a rate of 0.33%/day, in contrast to the rate of 0.07%/day obtained with tubes prepared the day before the analyses. Satisfactory precision and maximum sensitivity were obtained by using six replicates for each sample and freshly coated tubes. The antisera used for coating the tubes were reused four times and were frozen between coatings. The process of drum drying mashed potatoes containing 1 mug of SEB per g of mashed potatoes inactivated 83% (wt/wt) of the SEB. Statistical quality control parameters were used to insure that RIAs were performing reliably with a sensitivity of 1 ng/ml. Over 450 samples of potato flakes and granules, which represented different production lots from 12 different manufacturers, were examined for SEA, SEB, and SEC. No enterotoxins were detected.
Destruction of Staphylococcus aureus during frankfurter processing
Authors: Palumbo S A , Smith J L , Kissinger J C
Published: January 2020

We studied the thermal resistance of Staphylococcus aureus during frankfurter processing in respect to whether staphylococci are killed by the heating step of the process and whether heat injury interferes with the quantitative estimation of the survivors. With S. aureus 198E, heat injury could be demonstrated only when large numbers of cells (10(8)/g) were present and at a product temperature of 140 degrees F (60 degrees C). On tryptic soy agar and tryptic soy agar plus 7% NaCl media, at temperatures less than 140 degrees F, the counts were virtually identical; above 140 degrees F, the counts converged, with the organisms dying so rapidly that heat injury was not demonstrable. Heat injury was thus judged not to interfere with the quantitative estimation of staphylococci surviving the normal commercial heating given frankfurters. By using a combination of direct plating on tryptic soy agar and a most-probable-number technique, we detected no viable cells (less than 0.3/g) of several strains of S. aureus in frankfurters heated to 160 degrees F (71.1 degrees C). This temperature is compatible with the normal final temperature to which federally inspected processors heat their frankfurters and with the temperature needed to destroy salmonellae.
Macromolecule synthesis of Escherichia coli BB at a lower or transient growth state
Authors: Sawada T , Chohji T , Kuno S
Published: January 2020

Macromolecule synthesis in Escherichia coli BB at lower growth rates was investigated. The results indicate that a deviation in ribonucleic acid (RNA) content per cell at a lower growth rate from the exponential relationship to a specific growth rate is entirely attributable to the presence of nonviable cells, in which the RNA content is lower than in viable cells. Based on this fact, a mathematical expression of macromolecule contents versus specific growth rate was devised. Moreover, continuous changes in macromolecule content during unbalanced growth from late-logarithmic phase to stationary phase were measured. Although growth rates changed continuously, the data on deoxyribonucleic acid (DNA) or RNA content versus the specific growth rate calculated from the increments in cell number satisfactorily fitted the exponential lines obtained under balanced growth at a higher growth rate. However, no such relationship was observed in the plot of DNA or RNA content versus the specific growth rate calculated from the increments in optical density.
Response to polychlorinated biphenyls of marine phytoplankton isolates cultured under natural conditions
Authors: Powers C D , Rowland R G , O'Connors H B , Wurster C F
Published: January 2020

Polychlorinated biphenyls (PCB) at a concentration of 10 mug/liter substantially but temporarily suppressed the growth rate and photosynthesis of two species of Thalassiosira recently isolated from Long Island Sound and grown in dialysis membrane bags suspended in the tidal channel of an estuarine marsh. Inhibition of carbon fixation was apparently due to reduced levels of chlorophyll a per PCB-treated cell, but no significant loss of function per unit of existing chlorophyll a was observed. Cell concentrations in all size classes (3.2- to 18.6-mum-equivalent spherical diameters) were markedly lower in PCB-treated cultures, with toal biomass equaling only 30% of that in control cultures throughout the experiment.
Production of vitamin B-12 in tempeh, a fermented soybean food
Authors: Liem I T , Steinkraus K H , Cronk T C
Published: January 2020

Several varieties of soybeans contained generally less than 1 ng of vitamin B-12 per g. It was found that use of a lactic fermentation typical of tropical conditions during the initial soaking of the soybeans did not influence the vitamin B-12 content of the resulting tempeh. Pure tempeh molds obtained from different sources did not produce vitamin B-12. It was found that the major source of vitamin B-12 in commercial tempeh purchased in Toronto, Canada, was a bacterium that accompanies the mold during fermentation. Reinoculation of the pure bacterium onto dehulled, hydrated, and sterilized soybeans resulted in the production of 148 ng of vitamin B-12 per g. The presence of the mold, along with the bacterium, did not inhibit or enhance production of vitamin B-12. Nutritionally significant amounts of vitamin B-12 were also found in the Indonesian fermented food, ontjom.
Beneficial effects of catalase or pyruvate in a most-probable-number technique for the detection of Staphylococcus aureus
Authors: Brewer D G , Martin S E , Ordal Z J
Published: January 2020

The effects of the addition of catalase (EC 1.11.1.6) or pyruvate on the enumeration of Staphylococcus aureus in Trypticase soy broth with 10% NaCl were examined using a most-probable-number technique. Addition of catalase or pyruvate to the broth increased enumeration of all heat-stressed S. aureus strains tested. Increases were also observed with nonstressed cells. Catalase and pyruvate were similarly effective when added to Trypticase soy broth-10% NaCl in enumerating staphylococci naturally present in low-temperature-rendered ground-beef samples.
Comparison between two methods of assaying relative microbial activity in marine environments
Authors: Griffiths R P , Hayasaka S S , McNamara T M , Morita R Y
Published: January 2020

Two methods for determining relative microbial activity in the marine environment were compared. In one method, a single concentration of a labeled substrate was used to calculate rates of substrate utilization; in the other, multiple concentrations of the same substrate (heterotrophic activity method) were used to calculate maximum potential substrate utilization rates. These studies were made on 232 seawater and 79 sediment samples taken from a variety of marine environments. The highest correlations between these two methods were seen in the sediment samples tested. The lowest correlation coerfficient seen in the sediment samples was 0.90, and the highest was 0.98. In seawater samples (six studies), the lowest correlation coefficient was 0.77 and the highest was 0.95. The correlation between these two methods was also substrate concentration dependent. Higher correlation coefficients were observed when higher substrate concentrations were used. Under certain conditions, these two methods appear to be comparable for estimating relative levels of microbial activity in the marine environment.
Isolation and characteristics of a skatole-producing Lactobacillus sp. from the bovine rumen
Authors: Yokoyama M T , Carlson J R , Holdeman L V
Published: January 2020

A bacterium that is capable of decarboxylating indoleacetic acid to skatole (3-methylindole) has been isolated from an L-tryptophan enrichment of bovine rumen fluid. The bacterium is a gram-positive, nonmotile, nonsporeforming rod. It is an obligate anaerobe, and strains predominatly produce D-(-)-lactic acid, with smaller amounts of L-(+)-lactic acid and acetic acid, from sugar. All four strains isolated gave a negative reaction to the indole test because they cannot form skatole directly from tryptophan. This is the first report of indoleacetic acid decarboxylation to skatole in pure culture and the demonstration of skatole production by a Lactobacillus species.
Development of Poliovirus Having Increased Resistance to Chlorine Inactivation
Authors: Bates Robert C. , Shaffer Peter T. B. , Sutherland Susan M.
Published: January 2020

A laboratory strain of poliovirus (LSc) became progressively more resistant to chlorine inactivation during a series of repeated sublethal exposures to the halogen.
Viability of Rhizobium bacteroids
Authors: Tsien H C , Cain P S , Schmidt E L
Published: January 2020

Bacteroids prepared from nodules of soybean and bean were tested for viability. Contrary to the prevailing view that bacteroids are nonviable, it was found that bacteroids averaged 90% viability, irrespective of Rhizobium strain, nodule age, or nodule environment.
Production of volatile sulfur compounds during the decomposition of algal mats
Authors: Zinder S H , Doemel W N , Brock T D
Published: January 2020

Blue-green algal mats incubated anaerobically rapidly produce large amounts of volatile sulfur compounds, including hydrogen sulfide, methyl mercaptan, and dimethyl sulfide. The major organic sulfur compound is methyl mercaptan, in contrast to previous results with marine eucaryotic algae. Light inhibited production of volatile sulfur compounds, apparently because the algae then produced O2, rendering the system aerobic.
Use of an organoleptic tracer (mercaptan) for testing for leaks in safety equipment
Authors: Malligo J E
Published: January 2020

A safe, rapid, sensitive, and economical method is presented for detecting leaks in gas-tight laboratory cabinets and other apparatus. This method, using no fluorocarbons and requiring no prior decontamination, is effective under negative, neutral, or positive chamber conditions.
Wild rice as fermentation substrate for mycotoxin production
Authors: Lindenfelser L A , Ciegler A , Hesseltine C W
Published: January 2020

Many cereal grains have been studied for their suitability as substrates for the fermentative production of mycotoxins. However, except for aflatoxin, wild rice has not been investigated. Hence, five mold cultures known to produce the mycotoxins ochratoxin-A, penicillic acid, patulin, vomitoxin, and zearalenone were grown on wild rice under varying conditions of moisture and temperature to determine whether this grain would serve as a suitable substrate for toxin production. Under appropriate fermentation conditions, good yields of ochratoxin-A and moderate amounts of patulin were obtained, but only small amounts of penicillic acid, vomitoxin, and zearalenone were elaborated. An extract from a sample of naturally molded wild rice contained 0.8 microgram of patulin per g of rice. The predominating mold was identified as Aspergillus clavatus. Under identical cultural conditions, this isolate and a known patulin-producing strain of A. clavatus yielded approximately equivalent amounts of the mycotoxin.
Ruminococcus flavefaciens Cell Coat and Adhesion to Cotton Cellulose and to Cell Walls in Leaves of Perennial Ryegrass (Lolium perenne)
Authors: Latham M. J. , Brooker B. E. , Pettipher G. L. , Harris P. J.
Published: January 2020

Ruminococcus flavefaciens
was shown to possess a prominent glycoprotein coat, which contained rhamnose, glucose, and galactose as its principal carbohydrates. Periodate-reactive carbohydrate occurred as a surface layer of the coat. The ruminococci adhered strongly by means of this coat to cotton cellulose and to cell walls in leaf sections of
Lolium perenne
L. (perennial ryegrass). The coat was diffuse at the point of contact so that the bacterial cell wall was in close contact with the substrate. Adhesion was influenced by the availability of damaged plant cell walls and by the cell wall type and occurred most rapidly to cell walls of the epidermis and sclerenchyma, followed by the phloem and mesophyll. Plaques of bacteria with filamentous coat extensions developed on all these tissues. The bacteria did not readily adhere to the walls of the bundle sheath cells or metaxylem or protoxylem vessels and did not adhere to the cuticle or chloroplasts. The epidermal and phloem cell walls were more rapidly digested than the walls of other cell types.
Analysis of bacterial fermentation products by isotachophoresis
Authors: van der Hoeven J S , Franken H C , Camp P J , Dellebarre C W
Published: January 2020

Various carboxylic acids from bacterial fermentation could easily be separated by isotachophoresis. The analyses were performed on an LKB 2127 Tachophor, and under the conditions used the minimum amount of sample that could be quantitatively estimated was approximately 0.1 nmol. The reproducibility of the method was good (ca. 5 percent). The time of analysis using a 23-cm column was 12 min. No pretreatment of the samples was required.
Effects of Substrate Biodegradability on the Mass and Activity of the Associated Estuarine Microbiota
Authors: Bobbie Ronald J. , Morrison Susan J. , White David C.
Published: January 2020

Multiple biochemical assays of microbial mass and activities were applied to the estuarine detrital microbiota colonizing morphologically similar polyvinyl chloride needles and needles from slash pine (
Pinus elliottii
). Biodegradable pine needles consistently showed 2- to 10-fold higher values of extractable adenosine 5′-triphosphate, rates of oxygen utilization, activities of alkaline phosphatase and phosphodiesterase, and the mucopeptide cell wall component muramic acid than did the polyvinyl chloride needles, during a 14-week incubation in a semitropical estuary. The higher activities by the microbiota of the biodegradable substrate correlated with estimates of the microbial density from scanning electron microscopy. The microbial community associated with the nondegradable substrate showed minimal activity of β-
d
-galactosidase, β-
d
-glucosidase, and α-
d
-mannosidase in contrast to the biota of the degradable substrate, which showed 10- to 100-fold higher activities of these glycoesterases. These enzymes logically could be involved in catabolism of the carbohydrate polymers of the detritus. Assuming equivalent rates of predation, a surface that is also a utilizable substrate supports a three- to fivefold more active microbial population.
Isolation and characterization of Arthrobacter bacteriophages and their application to phage typing of soil arthrobacters
Authors: Brown D R , Holt J G , Pattee P A
Published: January 2020

Seventeen bacteriophages, active against 19 Arthrobacter soil isolates, were isolated from concentrated samples of river water and sewage. Attempts to isolate Arthrobacter bacteriophages from filtrates of broth cultures of the soil isolates or from ultraviolet light-irradiated cultures were unsuccessful. Bacteriophages were not detected in either concentrated or unconcentrated soil extracts. Electron microscopic studies of 11 phages showed morphologies characteristic of Bradley's groups B (exhibited by 9 phages) and C (exhibited by 2 phages). Moles percent guanine plus cytosine, calculated from the deoxyribonucleic acid density of three phages, ranged from 60.2 to 65.3. The phages were characterized by their plague and virion morphology, host range, and serological specificity.
Application of the fluorescent-antibody technique to the study of a methanogenic bacterium in lake sediments
Authors: Strayer R F , Tiedje J M
Published: January 2020

Fluorescent antibody (FA) was prepared for a methanogenic bacterium isolated from Wintergreen Lake pelagic sediment. The isolate resembles Methanobacterium formicicum. The FA did not cross-react with 9 other methanogens, including M. formicicum strains, or 24 heterotrophs, 18 of which had been isolated from Wintergreen Lake sediment. FA-reacting methanogens were detected in heat-fixed smears of several different lake sediments and anaerobic sewage sludge. Pretreatment of all samples with either rhodamine-conjugated geletin or bovine serum albumin adequately controlled nonspecific absorption of the FA. Autofluorescent particles were observed in the sediment samples but, with experience, they could easily be distinguished from FA-reacting bacteria. FA direct counts of the specific methanogen in Wintergreen Lake sediments were made on four different sampling dates and compared with five-tube most-probable-number estimates of the total methanogenic population that was present in the same samples. The FA counts ranged from 3.1 X 10(6) to 1.4 X 10(7)/g of dry sediment. The highest most-probable-number estimates were at least an order ofmagnitude lower.
Identification of
Beijerinckia
in the High Arctic (Devon Island, Northwest Territories)
Authors: Jordan D. C. , McNicol Patricia J.
Published: January 2020

Although generally considered, with few exceptions, to be restricted to the acidic, tropical soils of the southern hemisphere,
Beijerinckia
species, resembling
B. indica
, were found at three sites on Devon Island (75°33′N, 84°40′W) in the Canadian Arctic.
New sensitive biological assay for 12,13-epoxytrichothecenes
Authors: Siriwardana T M , Lafont P
Published: January 2020

Germination of Nicotiana sylvestris pollen is inhibited by T2 toxin and diacetoxyscirpenol. Based on this observation, an assay method was developed that is capable of detecting nanogram quantities of these toxins.