bluuebunny/crossref_metadata_2025 huggingface dataset:
Sulfide-Dependent Methane Production and Growth of a Thermophilic Methanogenic Bacterium
Authors: Rönnow Peter H. , Gunnarsson Lars Å. H.
Published: January 2020

Two strains of a thermophilic methanogenic bacterium, designated MT1 a and b, were isolated from a coastal surface sediment in the northern part of the Swedish West Coast. The two strains were identical in appearance and nutritional requirements and resembled
Methanobacterium thermoautotrophicum
. MT1 had an extraordinary requirement for sulfide. At sulfide levels below 0.1 mM, growth was poor and the methane production rate decreased. Other sources of sulfur, such as cysteine, sulfate, or thiosulfate, could not replace sulfide. The results indicate that a fast turnover rate of reduced sulfur compounds is involved in the energy metabolism of this organism.
Production and Evaluation of Antibody to the Heat-Stable Enterotoxin from a Human Strain of Enterotoxigenic
Escherichia coli
Authors: Kauffman Peter E.
Published: January 2020

Escherichia coli
heat-stable enterotoxin was coupled to bovine serum albumin by a carbodiimide reagent. Antibody to the conjugate was produced by immunization of rabbits. Data from radioimmunoassay and infant mouse tests indicate the presence of antibody to the enterotoxin. The antisera can be used in a radioimmunoassay to measure enterotoxin in various fluids.
Effect of defined lipopolysaccharide core defects on resistance of Salmonella typhimurium to freezing and thawing and other stresses
Authors: Bennett G M , Seaver A , Calcott P H
Published: January 2020

A family of mutants of Salmonella typhimurium with altered lipopolysaccharide (LPS) core chain lengths were assessed for sensitivity to freeze-thaw and other stresses. Deep rough strains with decreased chain length in the LPS core were more susceptible to novobiocin, polymyxin B, bacitracin, and sodium lauryl sulfate during growth, to ethylenediaminetetraacetic acid and sodium lauryl sulfate in resting suspension, and to slow and rapid freeze-thaw in water and saline, and these strains exhibited more outer membrane damage than the wild type or less rough strains. Variations in the LPS chain length did not dramatically affect the sensitivity of the strains to tetracycline, neomycin, or NaCl in growth conditions or the degree of freeze-thaw-induced cytoplasmic membrane damage. The deeper rough isogenic strains incorporated larger quantities of less-stable LPS and less protein into the outer membrane than did the wild type or less rough mutants, indicating that the mutations affected outer membrane synthesis or organization or both. Nikaido's model of the role of LPS and protein in determining the resistance of gram-negative bacteria to low-molecular-weight hydrophobic antibiotics is discussed in relation to the stress of freeze-thaw.
Isolation, Enumeration, and Maintenance of Rumen Anaerobic Fungi in Roll Tubes
Authors: Joblin K. N.
Published: January 2020

Anaerobic phycomycetous fungi have been isolated from rumen fluid by using the Hungate roll tube technique. Cultures on solid substrates in roll tubes can be stored for long periods, and fungal zoospores can be enumerated in roll tubes.
Assimilatory Sulfur Metabolism in Marine Microorganisms: Sulfur Metabolism, Protein Synthesis, and Growth of
Alteromonas luteo-violaceus
and
Pseudomonas halodurans
During Perturbed Batch Growth
Authors: Cuhel Russell L. , Taylor Craig D. , Jannasch Holger W.
Published: January 2020

The antibiotic protein synthesis inhibitor chloramphenicol specifically blocked the incorporation of [
35
S]sulfate into the residue protein of two marine bacteria,
Pseudomonas halodurans
and
Alteromonas luteo-violaceus
. Simultaneous inhibition of total protein synthesis occurred, but incorporation of
35
S into low-molecular-weight organic compounds continued.
A. luteo-violaceus
rapidly autolyzed, with similar reduction in cell counts, total culture protein and cellular sulfur, whereas
P. halodurans
remained viable. Treatment with chloramphenicol, growth during nitrogen and carbon limitation, and the carbon and energy sources used for growth did not alter the sulfur content of
P. halodurans
protein. The mean value (1.09%, by weight), representing a wide variety of environmentally relevant growth conditions, was in agreement with model protein composition. The variability of cellular composition of
P. halodurans
and
A. luteo-violaceus
is discussed with respect to the measurement of bacterial growth in natural environments. Total carbon and nitrogen per cell varied greatly (coefficient of variation, ca. 100%) depending on growth conditions. Variation in total sulfur and protein per cell was much less (coefficient of variation, <50%), but the least variation was found for sulfate incorporation into residue protein (coefficient of variation, ca. 15%). Thus, sulfate incorporation into residue protein can be used as an accurate measurement of de novo protein synthesis in these bacteria.
Inactivation of
Giardia
Cysts by Chlorine
Authors: Rice Eugene W. , Hoff John C. , Schaefer Frank W.
Published: January 2020

Cysts of
Giardia lamblia
from symptomatic and asymptomatic carriers had similar resistances to chlorination.
Isolation and characterization of new strains of cholesterol-reducing bacteria from baboons
Authors: Brinkley A W , Gottesman A R , Mott G E
Published: January 2020

We isolated and characterized nine new strains of cholesterol-reducing bacteria from feces and intestinal contents of baboons. Cholesterol-brain agar was used for the primary isolation, and subsequent biochemical tests were done in a lecithin-cholesterol broth containing plasmenylethanolamine and various substrates. All strains had similar colony and cell morphology, hydrolyzed the beta-glucosides esculin and amygdalin, metabolized pyruvate, and produced acetate and acetoin. Unlike previously reported strains, the nine new strains did not require cholesterol and an alkenyl ether lipid (e.g., plasmalogen) for growth; however, only two strains reduced cholesterol in the absence of the plasmalogen. These two strains also produced succinate as an end product. Carbohydrate fermentation was variable; some strains produced weak acid (pH 5.5 to 6.0) from only a few carbohydrates, whereas other strains produced strong acid reactions (pH less than or equal to 5.5) from a wide variety of carbohydrates.
In vitro utilization of mucin by Bacteroides fragilis
Authors: Roberton A M , Stanley R A
Published: January 2020

A method for isolating pig colon mucin in a soluble high-molecular-weight form, suitable for addition to bacterial growth media, is described. This preparation was utilized as a sole carbohydrate energy source by two strains of Bacteroides fragilis. The extent of degradation was compared with that of commercial pig gastric mucin by the same strains. Gas-liquid chromatographic analysis of the mucin carbohydrates and gel chromatography of the preparations were carried out before and after in vitro degradation. The mucin carbohydrates were utilized only to a very limited extent, colon mucin being more resistant to degradation than gastric mucin. Both mucins chromatographed at or near the excluded volume on Sepharose 4B, and only in the case of ATCC 25285 grown on gastric mucin was a significant degradation peak detected. If mucins are degraded in vivo by the sequential action of several bacteria, a pure culture in vitro might be expected to degrade mucins to a limited extent only. Techniques previously used to examine mucin utilization by pure cultures may have overlooked limited mucin degradation demonstrated by the methods used in this work.
Estimation of the most probable number with a programable pocket calculator
Authors: Koch A L
Published: January 2020

The most-probable-number method has many potential applications, particularly if many tubes per dilution and many dilution levels are used. Increasing the number of cultures is possible with modern automatic and semiautomatic equipment. However, available tables are not sufficiently detailed to handle data from a large number of culture tubes used in an assay. This paper provides a computer program capable of handling the necessary arithmetic and written for a hand-held, advanced programable calculator.
Effect of Hard Detergents on Algae in a High-Rate-Oxidation Pond
Authors: Azov Y. , Shelef G. , Narkis N.
Published: January 2020

Regular concentrations of hard detergents in domestic wastewater do not affect algal growth in a high-rate-oxidation pond. The addition of nonionic hard detergent at concentrations above 60 mg/liter decreased the algal concentration in the batch culture, and complete lysis of algal cells was observed within a few days at a detergent concentration of 100 mg/liter.
Denitrification in Marine Sediment: Measurement of Capacity and Estimate of In Situ Rate
Authors: Kaspar Heinrich F.
Published: January 2020

The acetylene block technique was used to assay denitrification in undisturbed sediment cores of an intertidal mud flat. Nitrogen loss due to this process was estimated at 1 to 41 kg of N/hectare (ha) per year. Anaerobic nitrate-saturated slurry of the same sediment had a denitrification capacity of 1,026 kg of N/ha per year. The acetylene block technique failed at low nitrate concentrations, so that denitrification at average in situ nitrate concentrations could not be determined. Denitrification followed zero-order kinetics at nitrate concentrations high enough to allow successful blockage of N
2
O reduction. Thus, an estimate of in situ rates based on kinetic parameters and in situ nitrate concentrations was impossible. No denitrification was observed in a slurry of the top 1.5 cm under aerated conditions and nitrate saturation. In undisturbed sediment, significant denitrification occurred in few discrete sites within a matrix of undetectable or low activity. Despite numerous errors contributing to the uncertainty of the estimate of in situ rates, the result obtained by this method was considered more valuable than the determination of denitrification capacities. Methods which include severe changes of physical and chemical parameters may frequently lead to overestimates of denitrification rates.
Interactions of Bacterial and Amoebal Populations in Soil Microcosms with Fluctuating Moisture Content
Authors: Bryant R. J. , Woods L. E. , Coleman D. C. , Fairbanks B. C. , McClellan J. F. , Cole C. V.
Published: January 2020

Sterilized soil samples (20 g of soil per 50-ml flask), amended with 600 μg of glucose-carbon and 60 μg of NH
4
-N · g of dry soil
−1
, were inoculated with bacteria (
Pseudomonas paucimobilis
) alone or with bacteria and amoebae (
Acanthamoeba polyphaga
). We used wet-dry treatments, which involved air drying the samples to a moisture content of approximately 2% and remoistening the samples three times during the 83-day experiment. Control treatments were kept moist. In the absence of amoebae, bacterial populations were reduced by the first drying to about 60% of the moist control populations, but the third drying had no such effect. With amoebae present, bacterial numbers were not significantly affected by the dryings. Amoebal grazing reduced bacterial populations to 20 to 25% of the ungrazed bacterial populations in both moisture treatments. Encystment was an efficient survival mechanism for amoebae subjected to wet-dry cycles. The amoebal population was entirely encysted in dry soil, but the total number of amoebae was not affected by the three dryings. Growth efficiencies for amoebae feeding on bacteria were 0.33 and 0.39 for wet-dry and constantly moist treatments, respectively, results that compared well with those previously reported for
Acanthamoeba
spp.
Incidence of Vibrio species associated with blue crabs (Callinectes sapidus) collected from Galveston Bay, Texas
Authors: Davis J W , Sizemore R K
Published: January 2020

Bacteria were readily isolated from the hemolymph of a majority (88%) of the blue crabs collected from Galveston Bay, Texas. The hemolymph of most crabs contained moderate (greater than 10(3) bacteria/ml) to heavy (greater than (10(5) bacteria/ml) infections. Large variances were observed in the bacterial number associated with individual crabs, but no significant difference was observed between the mean bacterial levels in the hemolymph of crabs collected during different seasons of the sampling year. Vibrio spp. were the predominant bacterial types in the hemolymph of infected crabs and increased in number significantly during the summer season. Warmer water temperatures were thought to be responsible for this increase. Bacterial numbers and the percentage of Vibrio spp. were highest in the interior of the crab bodies, especially in the digestive tract. The exterior of the crabs did not appear to be the source of the hemolymph's bacterial flora. Bacteria taxonomically identical to Vibrio cholerae. V. vulnificus, and V. parahaemolyticus were routinely isolated from the crab hemolymph and external carapace. V. parahaemolyticus was the most prevalent of the pathogenic Vibrio spp. and was isolated from 23% of the hemolymph samples. V. vulnificus (7%) and V. cholerae (2%) occurred less commonly in the hemolymph. The incidences of V. parachaemolyticus and V. vulnificus were related and increased in the summer months. Both organisms were frequently isolated from the same crab.
Wet and dry bacterial spore densities determined by buoyant sedimentation
Authors: Tisa L S , Koshikawa T , Gerhardt P
Published: January 2020

The wet densities of various types of dormant bacterial spores and reference particles were determined by centrifugal buoyant sedimentation in density gradient solutions of three commercial media of high chemical density. With Metrizamide or Renografin, the wet density values for the spores and permeable Sephadex beads were higher than those obtained by a reference direct mass method, and some spore populations were separated into several density bands. With Percoll, all of the wet density values were about the same as those obtained by the direct mass method, and only single density bands resulted. The differences were due to the partial permeation of Metrizamide and Renografin, but not Percoll, into the spores and the permeable Sephadex beads. Consequently, the wet density of the entire spore was accurately represented only by the values obtained with the Percoll gradient and the direct mass method. The dry densities of the spores and particles were determined by gravity buoyant sedimentation in a gradient of two organic solvents, one of high and the other of low chemical density. All of the dry density values obtained by this method were about the same as those obtained by the direct mass method.
Acetic Acid Production by
Clostridium thermoaceticum
in pH-Controlled Batch Fermentations at Acidic pH
Authors: Schwartz Robert D. , Keller Frederick A.
Published: January 2020

Four strains of the homofermentative, obligately anaerobic thermophile
Clostridium thermoaceticum
were compared in pH-controlled batch fermentation for their tolerance to acetic acid, efficiency of converting glucose to acetic acid and cell mass, and growth rate. At pH 6 (and pH 7) and initial acetic acid concentrations of less than 10 g/liter, the four strains had mass doubling times of 5 to 7 h and conversion efficiencies to acetic acid and cell mass of about 90% (70 to 110%) and 10%, respectively. At pH 6 and initial acetic acid concentrations of greater than 10 g/liter, only two of the strains grew, the mass doubling time increased to 18 h, and the conversion efficiencies to acetic acid and cell mass remained unchanged. Both of these strains had been selected for their ability to grow in the presence of acetate at neutral pH. The highest acetic acid concentrations reached were about 15 and 20 g/liter at pH 6 and 7, respectively.
C. thermoaceticum
is apparently more sensitive to free acetic acid than to either acetate ion or pH. It was also shown that, at pH 6 and 7, the redox potential must be at least as low as −300 and −360 mV, respectively, for growth to occur.
Generation of fecal and total coliform surges by stream flow manipulation in the absence of normal hydrometeorological stimuli
Authors: McDonald A , Kay D , Jenkins A
Published: January 2020

The response of Escherichia coli and total coliform concentration to increases in river discharge was investigated. Artificial hydrographs were generated on eight occasions between 21 October 1979 and 3 March 1981 by releasing water from Thruscross Reservoir in North Yorkshire into Fewston Reservoir. The majority of the releases were made after rainless periods to isolate the effects of stream channel entrainment from those induced by rainfall on the land surface. In the absence of rainfall, bacterial concentrations are shown to increase more than 10-fold in response to stage increases. It is suggested that two stores of bacteria must exist on the catchment, the first being a land store and the second a channel or near-channel store. Movement from the land to the channel store must relate to hill slope hydrological processes, whereas movement between stores in the channel fluvial system may be closely allied to sedimentary processes. Some consideration is given to bacterial levels in relation to European Economic Communities guidelines for contact recreation.
Effects of Surface Area and Flow Rate on Marine Bacterial Growth in Activated Carbon Columns
Authors: Shimp Robert J. , Pfaender Frederic K.
Published: January 2020

The colonization of granular activated carbon columns by bacteria can have both beneficial and potentially detrimental consequences. Bacterial growth on the carbon surface can remove adsorbed organics and thus partially regenerate the carbon bed. However, growth can also increase the levels of bacteria in the column effluents, which can adversely affect downstream uses of the treated water. This study of a sand column and several activated carbon columns demonstrated that considerable marine bacterial growth occurred in both sand and carbon columns and that this growth increased the number of bacteria in column effluents. Activated carbon supported approximately 50% more bacteria than did sand. Bacterial growth on activated carbon was reduced by increasing the flow rate through a carbon column and increasing the carbon particle size. Scanning electron micrographs showed that bacteria preferred to attach in the protected crevices on both the sand and carbon surface. The results of this study indicated that the colonization of activated carbon by marine bacteria was enhanced because of carbon's high surface area, its rough surface texture, and its ability to absorb organic materials.
Aerobic catabolism of bile acids
Authors: Leppik R A , Park R J , Smith M G
Published: January 2020

Seventy-eight stable cultures obtained by enrichment on media containing ox bile or a single bile acid were able to utilize one or more bile acids, as well as components of ox bile, as primary carbon sources for growth. All isolates were obligate aerobes, and most (70) were typical (48) or atypical (22) Pseudomonas strains, the remainder (8) being gram-positive actinomycetes. Of six Pseudomonas isolates selected for further study, five produced predominantly acidic catabolites after growth on glycocholic acid, but the sixth, Pseudomonas sp. ATCC 31752, accumulated as the principal product a neutral steroid catabolite. Optimum growth of Pseudomonas sp. ATCC 31752 on ox bile occurred at pH 7 to 8 and from 25 to 30 degrees C. No additional nutrients were required to sustain good growth, but growth was stimulated by the addition of ammonium sulfate and yeast extract. Good growth was obtained with a bile solids content of 40 g/liter in shaken flasks. A near-theoretical yield of neutral steroid catabolites, comprising a major (greater than 50%) and three minor products, was obtained from fermentor growth of ATCC 31752 in 6.7 g of ox bile solids per liter. The possible commercial exploitation of these findings to produce steroid drug intermediates for the pharmaceutical industry is discussed.
Starvation-Survival Physiological Studies of a Marine
Pseudomonas
sp
Authors: Kurath Gael , Morita Richard Y.
Published: January 2020

Starved cultures of a marine
Pseudomonas
sp. showed a 99.9% decrease in viable cell count during the first 25 days of starvation, yet the culture maintained 10
5
viable cells per ml for over 1 year. The physiological responses of populations of a marine
Pseudomonas
sp. to nutrient starvation were observed for periods of up to 40 days. At various intervals during starvation, the numbers of total, viable, and respiring cells were determined within the cultures. The ATP content, endogenous respiration rate, uptake rates, and percent respiration for exogenous glucose and glutamate were determined throughout the starvation period to characterize the physiological changes in the cells. It was observed that, after initial adjustment periods, all parameters tested reached stabilized states after 18 to 25 days of starvation. The results indicate that the actively respiring subpopulation, rather than the viable or total cell numbers, is the most appropriate denominator for interpretation of observed activities on an individual cell basis.
Foodborne enterotoxigenic Escherichia coli: detection and enumeration by DNA colony hybridization
Authors: Hill W E , Madden J M , McCardell B A , Shah D B , Jagow J A , Payne W L , Boutin B K
Published: January 2020

Four methods were compared for detecting heat-labile toxin production by Escherichia coli: DNA colony hybridization, two enzyme-linked immunosorbent assays, and the mouse Y-1 adrenal cell reaction. Although results of the methods were in general agreement, there were some differences in specificity and sensitivity. DNA colony hybridization was used to detect and enumerate enterotoxigenic E. coli isolates in artificially contaminated food without enrichment. Sensitivity level was 100 cells per g.
Variation in human herpesvirus susceptibility to enhancement by the pesticide carbaryl
Authors: Jerkofsky M , Abrahamsen L H
Published: January 2020

The ability of various human herpesviruses to be enhanced by the pretreatment of human embryonic lung cells with the pesticide carbaryl (1-naphthyl-N-methyl-carbamate) differs according to the virus tested. Different strains of varicella-zoster virus produced different patterns of susceptibility to enhancement. Laboratory-adapted strains were less sensitive to enhancement than were wild-type strains recently isolated from clinical specimens. The related human herpes simplex viruses types 1 and 2 and cytomegalovirus were negative for susceptibility to enhancement when either laboratory-adapted or wild-type strains were tested. No difference in the pattern of susceptibility was detected whether virus yields were determined by cell-associated or cell-free virus assay or when the input multiplicity was varied 10-fold.
Sampling strategy for detecting viruses in a sewage treatment plant
Authors: Rolland D , Joret J C , Villeval F , Block J C , Hartemann P
Published: January 2020

A study of pollutant flows was carried out at a wastewater treatment plant in Nancy, France, which used activated-sludge treatment. To carry out observation of hourly flow variation, a sampling strategy needs to be defined. A comparison between two methods of sampling was conducted: dip samples every 2 h over a period of 24 h and one 24-h composite sample were taken from raw and treated wastewater and then analyzed for enteroviruses, fecal coliforms, chemical oxygen demand, biochemical oxygen demand, and suspended solids. The results showed that the hourly variations of these pollutants in the effluents are in good agreement with expectations based upon the customers' usage and the characteristics of the wastewater network. Significant correlations were found between all tested parameters and enteroviruses in raw wastewater. After biological treatment, no correlation remained in treated wastewater between viruses and other parameters. As for the two sampling methods, a rather good representation of the daily load was given by the composite mode of sampling as concerns physicochemical and microbiological parameters. Biological treatment removed an average of 83% of viruses.
Effect of heat on virus inactivation by ammonia
Authors: Burge W D , Cramer W N , Kawata K
Published: January 2020

The rate of inactivation of bacteriophage f2 and poliovirus 1 (CHAT) by NH3 was strongly influenced by temperature. The process was pseudo-first order at all temperatures and NH3 concentrations. Poliovirus was inactivated at a greater rate than f2, but the change in the rate of inactivation with increasing temperature in the range of approximately 10 to 40 degrees C was greater for f2 than for poliovirus. At higher temperatures, the rate of change was greater for poliovirus. Arrhenius plots of the data were biphasic, indicating that two inactivation processes were occurring, one for the low temperature range and another for the high temperature range. However, the magnitudes of the thermodynamic variables for f2 were low enough, as calculated for the low (10 to 35 degrees C) and high (35 to 60 degrees C) phases, that inactivation could have occurred by breakage of nucleic acid chains. For poliovirus, the sizes indicated possible involvement of nucleic acid at the low temperatures (10 to 40 degrees C) but some unknown mechanism for the high temperatures (40 and 50 degrees C).
Viricidal Effects of
Lactobacillus
and Yeast Fermentation
Authors: Gilbert Jeannine P. , Wooley Richard E. , Shotts Emmett B. , Dickens J. Andra
Published: January 2020

The survival of selected viruses in
Lactobacillus
- and yeast-fermented edible waste material was studied to determine the feasibility of using this material as a livestock feed ingredient. Five viruses, including Newcastle disease virus, infectious canine hepatitis virus, a porcine picornavirus, frog virus 3, and bovine virus diarrhea, were inoculated into a mixture of ground food waste (collected from a school lunch program) containing
Lactobacillus acidophilus.
Mixtures were incubated at 20, 30, and 40�C for 216 h. In a second trial, four viruses, including Newcastle disease virus, infectious canine hepatitis virus, frog virus 3, and a porcine picornavirus, were inoculated into similar edible waste material containing
Saccharomyces cerevisiae.
Mixtures were incubated at 20 and 30�C for 216 h. Samples were obtained daily for quantitative (trial 1) and qualitative (trial 2) virus isolation. Temperature, pH, and redox potential were monitored. Controlled pH and temperature studies were also done and compared with the inactivation rates in the fermentation processes. In trial 1 (
Lactobacillus
fermentation), infectious canine hepatitis virus survived the entire test period in the fermentation process but was inactivated below pH 4.5 in the controlled studies. Newcastle disease virus was inactivated by day 8 in the fermentation process and appeared to be primarily heat sensitive and secondarily pH sensitive in the controlled studies. The porcine picornavirus survived the fermentation process for 8 days at 20�C but was inactivated more rapidly at 30 and 40�C. The controlled studies verified these findings. Frog virus 3 was inactivated by day 3 in the fermentation process and appeared to be sensitive to low pH in the controlled studies. Bovine virus diarrhea was rapidly inactivated in the fermentation process (less than 2 h) and was pH and temperature sensitive. In trial 2 (yeast fermentation), infectious hepatitis virus survived the entire test period in the fermentation process. Newcastle disease virus was inactivated by day 7 at 20�C and day 6 at 30�C. The porcine picornavirus was inactivated by day 7 at 30�C but survived the entire test period at 20�C. Frog virus 3 was inactivated by day 3 at 20�C and day 2 at 30�C.
Trypsin-treated Ma-104: a sensitive cell line for isolating enteric viruses from environmental samples
Authors: Agbalika F , Hartemann P , Foliguet J M
Published: January 2020

During a 1-year survey of enteroviruses in wastewater samples from the Lorraine area, three widely used continuous monkey kidney cell lines were tested: BGM, Vero, and trypsin-treated Ma-104. Decontaminated samples from secondary wastewater treatment plants (influent or effluent) were directly inoculated onto cells, and viruses were revealed after two passages with a liquid medium technique. Out of the total percentage of positive isolates with the three systems (32.7) 24.7% were found with Ma-104, 14.1% with BGM, and only 1.7% with Vero cells. Poliovirus was recovered more frequently with Ma-104 (12.3%) than with BGM (1.7%). Reovirus (3.5%) and echovirus (1.7%) were only found with Ma-104 cells; however, BGM cells allowed the isolation of a few group B coxsackieviruses (5.9%). It must be pointed out that 7.0% of samples with an unconfirmed cytopathic effect were found with BGM against 3.4% found with Ma-104, but they did not have significant differences. Because of its large spectrum of sensitivity, easy maintenance, and resistance to toxic effects, trypsin-treated Ma-104 may be recommended in conjunction with other cell lines for the detection of viruses from environmental samples, especially with the use of a liquid method.
Bacterial conjugation in the digestive tracts of gnotoxenic chickens
Authors: Lafont J P , Bree A , Plat M
Published: January 2020

Escherichia coli K-12 Hfr and F- strains were successively implanted in axenic chicks. Conjugation with exchanges of chromosomal genes occurred with high frequencies in the gut of the chicks and could continue as long as fertile strains coexisted in this environment. Almost all of the expected recombinant types were recovered in the feces under these experimental conditions. Furthermore, these recombinants were analogous to those obtained after conjugations in vitro. Recombinants formed in the gut were more numerous when the F- strain was seeded before the Hfr strain. The recombinants showed no apparent selective advantage over the parental strains in the intestinal medium. They were maintained throughout the experimental period and represented more than 10% of the total intestinal flora. The chick gut is usually rapidly colonized by other bacterial types under natural conditions. The possible effects of other components of the bacterial flora on conjugation of E. coli in holoxenic animals will require subsequent work with more complex microbiological conditions.
Improved Double-Vial Radiorespirometric Technique for Mineralization of
14
C-Labeled Substrates
Authors: Coveney Michael F. , Wetzel Robert G.
Published: January 2020

New procedures which simplify sample preparation and improve counting efficiency were developed for double-vial radiorespirometry. Under certain conditions, efficiency of fluor-NaOH-impregnated wicks was not stable, but was adversely affected by water vapor, NaOH concentration, and CO
2
loading. Glass fiber wick material treated with a methanolic fluor-NaOH solution showed improved
14
C counting efficiency (58%) compared with previous methods.
Effect of Buffering Media with Phosphates on Antibiotic Resistance of Lactic Streptococci
Authors: Sinha R. P.
Published: January 2020

Buffering complex growth media with inorganic or organic phosphates increased the resistance levels of lactic streptococci to aminoglycoside antibiotics, whereas it increased their sensitivity to erythromycin, penicillin, and tetracycline. The results suggest the need for caution in the selection of media for testing the antibiotic sensitivity of lactic streptococci.
Simultaneous concentration of four enteroviruses from tap, waste, and natural waters
Authors: Guttman-Bass N , Nasser A
Published: January 2020

The efficiency of virus recovery from water was investigated by using a method which enabled the concentration of a mixture of four enteroviruses with determination of their individual recovery efficiencies. The four viruses used (poliovirus 1, coxsackievirus A9, coxsackievirus B1, and echovirus 7) represented each of the four major subgroups of enteroviruses. This method, which was based on selective antibody neutralization, was used to investigate the effects of input water quality on enterovirus concentration by Balston filters (grade C; Balston, Inc., Lexington, Mass.) and organic flocculation. With tap water, the average recovery efficiency of the four viruses was 97%. Concentration from natural waters, including samples from two lakes (Lake Kinneret and the Hula Nature Reserve) and the Mediterranean Sea, resulted in similarly high average recovery efficiencies. Echovirus 7 was recovered with a slightly lower average efficiency from these types of water than were the other viruses. In comparison with other types of water, virus concentration from Jerusalem wastewater generally had a slightly lower efficiency of recovery, ranging from 63 to 75% for each of the viruses, with an overall average of 68%. The ability of each concentration step, membrane filtration or organic flocculation, to recover the viruses from water was assayed. For the filtration step, although there were not large differences in virus recoveries from tap water, echovirus 7 was recovered with the lowest efficiency (72%), and poliovirus 1 was recovered with the highest (87%) efficiency. Overall virus recovery by the filtration step was least efficient for wastewater (73%) and most efficient for seawater (107%).(ABSTRACT TRUNCATED AT 250 WORDS)
Method for Growth and Purification of Bacteriophage 643 on
Streptococcus lactis
ML3
Authors: Lyttle David J. , Petersen George B.
Published: January 2020

The yield of bacteriophage 643 was increased by infecting cultures of
Streptococcus lactis
ML3 in late-log phase growth, harvesting the infected cells, and suspending them in fresh, phosphate-buffered minimal medium. The cells lysed after this treatment and produced high titers of bacteriophage. The phage particles were dissociated from debris by 2 M NaCl and purified by differential and CsCl band centrifugation.
Characterization of plant polysaccharide- and mucin-fermenting anaerobic bacteria from human feces
Authors: Bayliss C E , Houston A P
Published: January 2020

Organisms able to grow on arabinogalactan, pectin, xylan, wheat bran, guar, apple cell walls, and mucin were isolated by enrichment from human feces. The number of polysaccharide fermenters and the properties of the predominant bacteria varied between subjects. The ability to use one polysaccharide was not related to the ability to use others. Some organisms (e.g., Bacteroides spp.) isolated on other substrates also utilized mucin, but were not isolated in the mucin enrichment. The mucin fermenters isolated by enrichment had a very restricted ability to utilize complex polysaccharides and their constituent monosaccharides, suggesting that the presence of plant polysaccharides in the human colon is unlikely to prevent the use of colonic mucin as an energy source by bacteria. Characterization with a range of biochemical tests showed that many of the isolates, but especially the mucin fermenters, did not resemble organisms described previously.
Survey of drug and phage resistance and colicin and hemolysin production among coliforms isolated in the Ivory Coast
Authors: Trudel L , Arriaga-Alba M , Lavoie M C
Published: January 2020

Analysis of 178 strains isolated as total and fecal coliforms in the Ivory Coast revealed that (i) hemolytic activity was scarce (0.6%) among this bacterial population; (ii) the most prevalent colicins detected were, in decreasing order, E, I, A, and G; (iii) the frequency of coliphage and drug resistance was similar to that observed in other countries, except for those of drug-resistant strains in animal feces, which were lower than in countries where animals are antibiotic fed; and (iv) one of the drug resistance plasmids seemed to possess a restriction-modification system and another seemed to code for capsular material.
Ethanol contamination in commercial buffers: ethanol contaminating tris-maleate and other commercial buffers induces germ tube formation in Candida albicans
Authors: Pollack J H , Hashimoto T
Published: January 2020

Evidence is presented for the presence of trace amounts of ethanol in certain commercial buffers. It was shown that germ tube formation occurring in Candida albicans suspended in the buffers was due to the contaminating ethanol.
Effects of humic and fulvic acids on poliovirus concentration from water by microporous filtration
Authors: Sobsey M D , Hickey A R
Published: January 2020

Because naturally occurring organic matter is thought to interfere with virus adsorption to microporous filters, humic and fulvic acids isolated from a highly colored, soft surface water were used as model organics in studies on poliovirus adsorption to and recovery from electropositive Virosorb 1MDS and electronegative Filterite filters. Solutions of activated carbon-treated tap water containing 3, 10, and 30-mg/liter concentrations of humic or fulvic acid were seeded with known amounts of poliovirus and processed with Virosorb 1MDS filters at pH 7.5 or Filterite filters at pH 3.5 (with and without 5 mM MgCl2). Organic acids caused appreciable reductions in virus adsorption and recovery efficiencies with both types of filter. Fulvic acid caused greater reductions in poliovirus recovery with Virosorb 1MDS filters than with Filterite filters. Fulvic acid interference with poliovirus recovery by Filterite filters was overcome by the presence of 5 mM MgCl2. Although humic acid reduced poliovirus recoveries by both types of filter, its greatest effect was on virus elution and recovery from Filterite filters. Single-particle analyses demonstrated MgCl2 enhancement of poliovirus association with both organic acids at pH 3.5. The mechanisms by which each organic acid reduced virus adsorption and recovery appeared to be different for each type of filter.
Partial Isolation and Degradation of Caseins by Cell Wall Proteinase(s) of
Streptococcus cremoris
HP
Authors: Exterkate Fred A. , de Veer Gerrie J. C. M.
Published: January 2020

The cell wall proteinase fraction of
Streptococcus cremoris
HP has been isolated. This preparation did not exhibit any activity due to either specific peptidases known to be located near the outside surface of and in the membrane or intracellular proteolytic enzymes. By using thin-layer chromatography for the detection of relatively small hydrolysis products which remain soluble at pH 4.6, it was shown that β-casein is preferentially attacked by the cell wall proteinase. This was also the case when whole casein or micelles were used as the substrate. κ-casein hydrolysis is a relatively slow process, and α
s
-casein degradation appeared to proceed at an extremely low rate. These results could be confirmed by using
14
CH
3
-labeled caseins. A relatively fast and linear initial progress of
14
CH
3
-labeled β-casein degradation is not inhibited by α
s
-casein and only slightly by κ-casein at concentrations of these components which reflect their stoichiometry in the micelles. Possible implications of β-casein degradation for growth of the organism in milk are discussed.
Presence of microorganisms in hemolymph of the horseshoe crab Limulus polyphemus
Authors: Brandin E R , Pistole T G
Published: January 2020

Hemolymph samples obtained from Limulus polyphemus at the time of collection and after a 1-week holding period exhibited a significant increase in bacterial levels. No differences were observed in the ability of amoebocyte lysate, prepared from these same samples, to gel in the presence of lipopolysaccharide.
Distribution of Alginate Lyase Activity among Strains of
Bacillus circulans
Authors: Hansen Jeffrey B. , Nakamura Lawrence K.
Published: January 2020

Strains from four different DNA relatedness groups of
Bacillus circulans
showed apparent alginate lyase activity; the activity of three strains examined had mannuronidase specificity. A representative strain of group 4 also produced apparent inducible unsulfated chrondroitin lyase activity.
Erwinia herbicola isolates from alfalfa plants may play a role in nodulation of alfalfa by Rhizobium meliloti
Authors: Handelsman J , Brill W J
Published: January 2020

Erwinia herbicola was isolated from roots of plants derived from surface-sterilized seeds of all alfalfa varieties that were tested. Some of these E. herbicola strains affected nodulation by certain strains of Rhizobium meliloti. In previously published work we presented the isolation of slow-and fast-nodulating variants from a single culture of R. meliloti 102F51. In the absence of E. herbicola, the slow-nodulating variant induced the formation of nodules on alfalfa as rapidly as the faster-nodulating strain. The rates of nodulation by the faster-nodulating variant were the same in the presence and absence of E. herbicola. All of the previously reported slower-nodulating strains derived from R. meliloti 102F51 nodulated more rapidly on sterilized plants than in the presence of certain E. herbicola isolates.
Use of bituminous coal as an alternative technique for field concentration of waterborne viruses
Authors: Dahling D R , Phirke P M , Wright B A , Safferman R S
Published: January 2020

A filter system that sandwiches a bituminous coal preparation between two prefilters was comparable to those presently used to recover human viruses from large volumes of water. This filter was effective over a pH range of 3.0 to 7.0. Poliovirus type 1 recoveries from 100-liter seeded samples of Cincinnati tap water did not vary significantly when compared with those of identical samples processed through Filterite and Millipore filters. In studies with raw domestic sewage, virus recoveries were nearly identical from comparable samples filtered through coal and Millipore disk filters. Thus, the availability of coal makes this filter system an inexpensive analytical tool, especially in developing nations, for virus concentration.
Improvement of Protoplast Regeneration by Growing Yeast Cells Hypertonically
Authors: Ahn J. S. , Pack M. Y.
Published: January 2020

The high osmotic pressure provided for in vitro transformation processes to support naked protoplasts of
Saccharomyces cerevisiae
was found to hurt regeneration of the protoplasts to walled cells. Preadaptation of the cells by growth under the same hypertonic conditions as those used for transformation doubled the rate of protoplast regeneration and in turn resulted in a higher yield of transformants.
Microbial mineralization of ring-substituted anilines through an ortho-cleavage pathway
Authors: Zeyer J , Wasserfallen A , Timmis K N
Published: January 2020

Moraxella sp. strain G is able to utilize as sole source of carbon and nitrogen aniline, 4-fluoroaniline, 2-chloroaniline, 3-chloroaniline, 4-chloroaniline (PCA), and 4-bromoaniline but not 4-iodoaniline, 4-methylaniline, 4-methoxyaniline, or 3,4-dichloroaniline. The generation time on PCA was 6 h. The pathway for the degradation of PCA was investigated by analysis of catabolic intermediates and enzyme activities. Mutants of strain G were isolated to enhance the accumulation of specific pathway intermediates. PCA was converted by an aniline oxygenase to 4-chlorocatechol, which in turn was degraded via a modified ortho-cleavage pathway. Synthesis of the aniline oxygenase was inducible by various anilines. This enzyme exhibited a broad substrate specificity. Its specific activity towards substituted anilines seemed to be correlated more with the size than with the electron-withdrawing effect of the substituent and was very low towards anilines having substituents larger than iodine or a methyl group. The initial enzyme of the modified ortho-cleavage pathway, catechol 1,2-dioxygenase, had similar characteristics to those of corresponding enzymes of pathways for the degradation of chlorobenzoic acid and chlorophenol, that is, a broad substrate specificity and high activity towards chlorinated and methylated catechols.
Comparison of animal infectivity and excystation as measures of Giardia muris cyst inactivation by chlorine
Authors: Hoff J C , Rice E W , Schaefer F W
Published: January 2020

In this study, in vitro excystation and mouse infectivity were compared as methods for quantitatively determining the viability of Giardia muris cysts before and after exposure to free residual chlorine. The mouse infectivity results show that very few cysts (1 to 15) constitute an infectious dose. The results of the inactivation studies indicate that in vitro excystation is an adequate indication of G. muris cyst infectivity for the host and can be used to determine the effects of disinfectants on cyst viability.
Influence of Deep Ocean Sewage Outfalls on the Microbial Activity of the Surrounding Sediment
Authors: Novitsky James A. , Karl David M.
Published: January 2020

The microbial activity near two deep ocean sewage outfalls off the coast of the island of Oahu, Hawaii, was characterized. Water samples and sediment samples to a depth of 4.5 cm were analyzed from an area of approximately 4.5 � 10
4
m
2
surrounding the outfalls. Although the effluent water at both sites exhibited heterotrophic activity that was 2 orders of magnitude greater than water from a control site, ambient water samples taken within 1 m of the discharge ports exhibited activity only twice that of the control water. The heterotrophic activity of the outfall sediment was only elevated above that of the control site for surface samples collected within 10 m of the outfall. Likewise, the rates of microbial nucleic acid synthesis and carbon production in the sediment were only elevated immediately adjacent to the outfalls. Total microbial biomass, as determined by the ATP content of the sediment, varied spatially but was generally elevated at the outfall sites. The specific growth rates calculated for the sediment microbial populations, however, were not greater at the outfall sites. At one site the rocks surrounding the diffuser pipe were covered with copious amounts of slime that appeared to be composed entirely of microbial cells and filaments. This microbial mat was extremely active with respect to heterotrophic activity and biomass production. Overall, it appears that the impact of the sewage discharge on the ambient seawater microbiota is slight and that the effect on the sediment microbiota is confined to an area immediately adjacent to the diffuser ports. In the sand itself, the effect is limited to the upper 2 cm at most.
Fusarin C production by North American isolates of Fusarium moniliforme
Authors: Farber J M , Sanders G W
Published: January 2020

A liquid culture medium was developed to screen North American isolates of Fusarium moniliforme Sheldon and Fusarium subglutinans (Wollenw. and Reink.) Nelson, Toussoun, and Marasas for their ability to produce fusarin C. Parameters which were important for the optimal biosynthesis of fusarin C included pH (3.0 to 4.0), aeration, and sugar concentration (30 to 40%). Of seven sugars tested, sucrose and glucose were the best carbohydrate sources for mycotoxin production, resulting in levels of fusarin C of greater than 60 ppm (greater than 60 micrograms/g) in liquid culture (28 degrees C; 7 days). A time-course study of fusarin C production was done over a 21-day period, during which time pH values, glucose concentrations, nitrogen levels, and fungal biomass were determined. Of the two Fusarium spp. studied, 13 of 16 isolates of F. moniliforme produced fusarin C in liquid medium (14 of 16 in corn), while none of the 15 isolates of F. subglutinans studied was found to produce the compound. Levels of fusarin C produced by Fusarium sp. isolates growing on corn ranged from 18.7 to 332.0 micrograms/g.