bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a quantitative method for the detection of enteroviruses in soil
Authors: Hurst C J , Gerba C P
Published: January 2020

A method is described for efficiently concentrating enteroviruses from soil. Viruses were eluted from soil by mechanical agitation in high pH glycine buffer containing ethylenediaminetetraacetic acid. The eluted viruses were concentrated on a floc that formed de novo upon adjustment of the soil eluate to 0.06 M aluminum chloride and pH 3.5. Viruses not pelleted with the floc were concentrated by adsorption to and elution from membrane filters. This method yielded an average efficiency of 66% recovery from loamy sand soil for four enteroviruses. Virus recovery from soil was consistently high, with samples ranging in size from 25 to 500 g. The method was used successfully to isolate naturally occurring viruses from soil beneath a wastewater land treatment site. Recovery of enteroviruses by this method form different types of soil was dependent on percentage of clay, surface area, and cation exchange capacity. Recovery was not dependent on soil saturation pH or on percentage of organic matter. This method should prove useful for studying enterovirus migration and survival during the land application of domestic sewage.
Determinants in Microbial Colonization of the Murine Gastrointestinal Tract: pH, Temperature, and Energy-Yielding Metabolism of
Torulopsis pintolopesii
Authors: Artwohl James E. , Savage Dwayne C.
Published: January 2020

Torulopsis pintolopesii
is an indigenous yeast that colonizes the secreting epithelia in the stomachs of mice and rats. A wild-type strain of this microbe was isolated and identified. To attempt to learn characteristics of the yeast that are advantageous to it in colonizing its natural habitat in vivo, we examined some aspects of its nutrition and energy-yielding metabolism and some environmental conditions that influence its growth in vitro. The yeast appeared to be limited in the compounds it can utilize as carbon and nitrogen sources. It grew best at 37�C and did not grow at 23 or 43�C. It grew optimally at neutral pH but could grow aerobically at pH values as low as 2.0 and anaerobically at pH values as low as 3.4. As assessed by measurements of growth rates and yield coefficients, it grew better aerobically than anaerobically. When grown aerobically, it had a cyanide-sensitive system for taking up O
2
and tested positively for cytochrome
c
oxidase activity. A petite mutant strain isolated from the wild-type strain had a growth rate and yield coefficient when incubated aerobically that were essentially the same as those of the wild-type parent grown anaerobically. Likewise similar to the wild-type parent grown anaerobically, the petite strain, though incubated aerobically, did not take up O
2
. Yeast-free mice associated with either the wild-type or the petite mutant strain were colonized at essentially the same rates and to similar final population levels by both strains. The yeast's capacity to respire may be of little advantage to it in its natural environment. By contrast, its abilities to grow best at 37�C and to grow at low pH values are undoubtedly advantageous characteristics in this respect. The limitations in its carbon and nitrogen nutrition are difficult to evaluate as ecological factors in its colonization of the natural habitat.
Effect of environmental parameters on the biodegradation of oil sludge
Authors: Dibble J T , Bartha R
Published: January 2020

A laboratory study was conducted with the aim of evaluating and optimizing the environmental parameters of "landfarming", i.e., the disposal by biodegradation in soil of oily sludges generated in the refining of crude oil and related operations. Oil sludge biodegradation was monitored by CO2 evolution and by periodic analysis of residual hydrocarbons. The parameters studied were soil moisture, pH, mineral nutrients, micronutrients, organic supplements, treatment rate, teratment frequency, and incubation temperature. Oil sludge biodegradation was optimal at a soil water-holding capacity of 30 to 90%, a pH of 7.5 to 7.8, C:N and C:P ratios of 60:1 and 800:1, respectively, and a temperature of 20 degrees C or above. Addition of micronutrients and organic supplements was not beneficial; sewage sludge interfered with hydrocarbon biodegradation. Breakdown of the saturated hydrocarbon (alkane and cycloalkane) fraction was the highest at low application rates, but higher application rates favored the biodegradation of the aromatic and asphaltic fractions. An application rate of 5% (wt/wt) oil sludge hydrocarbon to the soil (100,000 liters/hectare) achieved a good compromise between high biodegradation rates and efficient land use and resulted in the best overall biodegradation rate of all hydrocarbon classes. Frequent small applications resulted in higher biodegradation than single large applications. Two 100,000-liter/hectare (255 barrels per acre) or four 50,000-liter/hectare oil sludge hydrocarbon applications per growing season seem appropriate for most temperate zone disposal sites.
Magnitude of pollution indicator organisms in rural potable water
Authors: Sandhu S S , Warren W J , Nelson P
Published: January 2020

A total of 460 water samples were randomly drawn from the potable water supply sources of rural communities in three counties of South Carolina. About 10% of the population, not incorporated in municipalities, was sampled. The samples were tested for total coliforms, Escherichia coli, and fecal streptococci. Significant levels of these pollution indicator organisms were detected in almost all the water supplies. Total coliforms were the most common, and only 7.5% of the water supplies were uncontaminated. E. coli, considered a reliable indicator of recent and dangerous pollution, was observed in 43% of the water supplies. Statistical analyses indicated that the bacterial populations, especially E. coli, were associated with the supply source depth and its distance from the septic tank. Total coliform counts were also weakly correlated to the pH of the water.
Evidence by electron micrographs for a high incidence of bacteriophage particles in the waters of Yaquina Bay, oregon: ecological and taxonomical implications
Authors: Torrella F , Morita R Y
Published: January 2020

A variety of viral particles, the majority of them clearly identifiable as bacteriophages, were found in the seawater of Yaquina Bay, Oregon. These phages were obtained as free particles from the seawater without employing specific hosts for enrichments or further purification in the laboratory. A variety of electron micrographs showing different morphologies of phages as well as phage-bacterium interactions found in the seawater are presented. In the area where the bay received organic enrichment from seafood processing plants, a minimum of 10(4) phage particles per ml was estimated. Since the technique used was designed to concentrate particles 0.2 micrometer in diameter or larger it is assumed that the actual number of phage particles is higher than 10(4) particles per ml. The implications of the presence of such phage concentrations in bays and estuaries with a certain level of eutrophication are of obvious importance in considering the microbial ecology of these environments.
Macromolecular composition of a Cellulomonas sp. cultivated in continuous culture under glucose and zinc limitation
Authors: Summers R J , Srinivasan V R
Published: January 2020

The mutant strain of Cellulomonas sp. (ATCC 21399) was cultivated under glucose and zinc limitation at a variety of growth rates in continuous culture. The growth characteristics and macromolecular composition of the population varied with the limitation imposed and the growth rate. Glucose- and zinc-limited cultures maintained a constant relative protein content. The relative ribonucleic acid content increased, whereas the carbohydrate and deoxyribonucleic acid contents decreased with an increase in the population growth rate in glucose-limited cultures. Free unbound lipid remained constant. The maximum population growth rate in zinc-limited cultures was directly proportional to the zinc concentration and demonstrated a traditional steady-state function. The nucleic acid content increased with increased growth rate; however, the relative nucleic acid content was significantly depressed when compared to glucose limited cells. This manner of cultivation may prove to be a useful tool for the production of single cell protein with lowered nucleic acid content and the elucidation of micronutrient involvement in growth-related processes.
Bacterial formation of omega-muricholic acid in rats
Authors: Sacquet E C , Raibaud P M , Mejean C , Riottot M J , Leprince C , Leglise P C
Published: January 2020

In the feces of conventional rats, the amount of omega-muricholic and hyodeoxycholic acids vary according to the diet. To understand this phenomenon, we investigated the bacterial formation of these bile acids. The present paper reports the first isolation, from conventional rat feces, of a strain of Clostridium group III which transforms beta-muricholic acid, the main bile acid in germfree rats, into omega-muricholic acid.
Propagation of ribonucleic acid coliphages in gnotobiotic mice
Authors: Ando A , Furuse K , Watanabe I
Published: January 2020

To clarify the propagation cycle of bacteriophages in their natural habitats, we tested whether animals could support ribonucleic acid (RNA) phage propagation in their intestines, using germfree mice as the test animal. Propagation of four different antigenic types of RNA phages was tested. No detectable propagation or colonization of RNA phages was observed either in germfree mice or in gnotobiotic mice infected with the F- strain of Escherichia coli. Propagation or colonization was observed when RNA phages were orally introduced into gnotobiotic mice harboring the F+ or F' strain of E. coli. These results were consistent with data for in vitro propagation experiments. Fecal titers of phages were monitored over 24 to 98 days and were found to vary from 10(5) to 10(11) plaque-forming units per g of feces. Streptomycin administration gradually led to the disappearance of bacteria and, concomitantly, the RNA phages. Phages recovered from gnotobiotic mice feces included some of novel antigenic types. The bacterial isolates recovered from gnotobiotic mice harboring F+ bacteria included the original F+ strain, strains which had become F-, and some which had become inefficient hosts for the propagation of RNA phages.
Enzyme-linked immunosorbent assay for detection of Clostridium botulinum type E toxin
Authors: Notermans S , Dufrenne J , Kozaki S
Published: January 2020

The enzyme-linked immunosorbent assay using the "double-sandwich" technique was utilized to determine Clostridium botulinum type E toxin. With this technique, about 80 mouse intraperitoneal 50% lethal doses of toxin could be detected. Cross-reaction was hardly observed with C. botulinum type A and B toxins. No cross-reaction was observed with culture supernatants of C. botulinum type C or other Clostridium strains. In all probability this was due to the high specificity of the antiserum prepared aginst the toxic component of type E toxin.
Effects of pH of the medium on flagellation of Vibrio parahaemolyticus
Authors: Kimura K , Tateiri S , Iida H
Published: January 2020

Formation of the lateral flagella by Vibrio parahaemolyticus was inhibited under an alkaline condition of the medium. However, flagellation of the polar monotrichous flagellum was not affected in the same condition. Flagellation of the lateral flagella depended on the pH of the medium.
Method for Salmonella concentration from water at pH 3.5, using micro-fiber glass filters
Authors: Block J C , Rolland D
Published: January 2020

A method is described for the concentration of Salmonella from water. As is done with enterovirus, Salmonella bacteria were concentrated from water in two steps: by pH 3.5 adsorption on and pH 9.5 elution from 8-micron porosity micro-fiber glass filter tubes. This method worked in less than 30 min, and Salmonella typhimurium was inactivated only slightly in spite of rapid pH variations (pH 3.5 to 9.5). It was demonstrated that the retention by the filters stems from two phenomena: a low retention in the micro-fiber glass labyrinth for small filtered volumes, and a high retention by adsorption at pH 3.5 for any filtered volume (experiments done with 15- and 80-liter samples). Addition in tap water of trivalent ions like Al3+ did not increase Salmonella adsorption. In most of the trials, Salmonella recovery varied from 42 to 93%. Preliminary field investigations indicate that enterovirus and Salmonella may both be concentrated from the same water sample by this procedure.
Toxic effects of some alcohol and ethylene glycol derivatives on Cladosporium resinae
Authors: Lee K H , Wong H A
Published: January 2020

Eleven commercially available alcohol and ethylene glycol derivatives were tested for their toxicity toward a problem organism in jet fuel, Cladosporium resinae. In the presence of glucose, 20% (vol/vol) ethylene glycol monomethyl ether prevented spore germination and mycelial growth, and 10% (vol/vol) 2-ethoxybutanol, 10% 2-isopropoxyethanol, 10% 3-methoxybutanol, 5% 2-butyloxyethanol, 5% ethylene glycol dibutyl ether, and 5% diethylene glycol monobutyl ether were found to have similar effects. In a biphasic kerosene-water system, 3-methoxybutanol, 2-butyloxyethanol, and diethylene glycol monobutyl ether were again found to be more toxic than ethylene glycol monomethyl ether. Considerable potassium efflux, protein leakage, and inhibition of endogenous respiration were observed in the presence of the more toxic compounds. 2-Butyloxyethanol also caused loss of sterols from cells.
Enterobacteriaceae isolated from iguanid lizards of west-central Texas
Authors: Mathewson J J
Published: January 2020

The prevalence of members of the family Enterobacteriaceae in the intestines of seven species of iguanid lizards native to west-central Texas was determined. Of the 67 lizard specimens examined, 48.7% were infected with Salmonella and 9% were infected with Salmonella arizonae. Two lizard species (Sceloporus olivaceus and Crotaphytus collaris) were shown to have a 100% prevalence of Salmonella.
Composition and biological properties of lipopolysaccharides isolated from Schizothrix calcicola (Ag.) Gomont (Cyanobacteria)
Authors: Keleti G , Sykora J L , Lippy E C , Shapiro M A
Published: January 2020

The most common cyanobacterium contaminating drinking water systems in southwestern Pennsylvania is Schizothrix calcicola. Lipoplysaccharides (LPS) were isolated from this species by hot phenol-water extraction. The polysaccharide moiety was composed of glucosamine, galactose, glucose, mannose, xylose and rhamnose. The lipid A part contained beta-hydroxylauric, myristic, pentadecanoic, palmitic, beta-hydroxypalmitic, stearic, oleic, and linoleic acids. In contrast to many LPS isolated from Enterobacteriaceae, the dominant component was not beta-hydroxymyristic but beta-hydroxypalmitic acid. The LPS induced Limulus lysate gelation and Schwartzman reaction but was nontoxic to mice. The identity of LPS was verified by alkali and lysozyme treatment. The results suggest that S. calcicola is one of the principal sources of endotoxins in water systems using open finished-water reservoirs.
Separation of botulinum-positive and -negative fish samples by means of a pattern recognition method applied to headspace gas chromatograms
Authors: Snygg B G , Andersson J E , Krall C A , Stöllman U M , Akesson C A
Published: January 2020

A gas chromatographic headspace technique was used to analyze the gas produced during putrefaction of pond-raised, degutted trout, incubated in evacuated plastic pouches. The following samples were analyzed; 10 samples which, due to natural contamination with Clostridium botulinum, were toxic when injected into mice, 10 samples which were nontoxic when injected, and 9 samples inoculated with one strain of C. botulinum type E. The gas chromatograms showed the presence of 118 compounds in most samples. Quantitative differences among most chromatograms could be observed, but no compound was unique to any of the three groups. By means of a specific pattern recognition method, all negative samples were shown to fall into one group and were distinctly separated from the toxic samples. No differences could be observed between the two groups of inoculated and naturally contaminated trout samples. The results suggest that headspace analysis combined with pattern recognition analysis might prove to be a valuable method for screening studies of foods containing living cells of C. botulinum.
Survival of enteric viruses under natural conditions in a subarctic river
Authors: Dahling D R , Safferman R S
Published: January 2020

The survival of enteric viruses was studied in the vicinity of Fairbanks, Alaska at selected stations along a 317-km section of the Tanana River. This section was located downstream from all known domestic wastewater sources and was effectively sealed by a total ice cover. The mean flow time through the region was 7.1 days, during which initial viral population showed a relative survival rate of 34%. The tracing of native viruses at such great distances in the complete absence of other point and nonpoint viral sources has not been previously reported. Of the two methods of virus concentration used, viral recoveries from the disk adsorption virus elution procedure were far greater than those achieved with the Aquella system employed at that time. The fact the ratio of enteric viruses to fecal indicator bacteria was not constant clearly inferred that these bacteria were not an effectual measure of virus concentration. The persistence of fecal coliforms and fecal streptococci, however, attested to the microbiological health risk involved.
Thermal inactivation and injury of Moraxella-Acinetobacter cells in ground beef
Authors: Firstenberg-Eden R , Rowley D B , Shattuck E
Published: January 2020

The thermal inactivation and injury (sensitivity to 0.8% NaCl) of a radiation-resistant culture of Moraxella-Acinetobacter mixed in minced beef were determined. Survival curves for Moraxella-Acinetobacter cells in beef had an initial shoulder preceding a logarithmic decline when the cells were heated at 65, 70, and 75 degrees C, but not at 80 degrees C. In all cases, the experimental points not included in the shoulder were linearized by means of a least-squares straight line, and the latter was used to determine D values. Shoulder values of 12.2, 4.1, and 0.6 min at temperatures of 65, 70, and 75 degrees C were added to the respective D values of 35.4, 6.6, and 1.4 min to determine the time required to destroy one log cycle. The Z value was 7.3 degrees C. Moraxella-Acinetobacter cells in meat were more rapidly injured than inactivated, on initial exposure to heat. The number of cells injured by this initial exposure increased as the temperature was increased. At 65 degrees C the percentage of injured cells increased more rapidly with exposure time than did the inactivated cells. As the temperature was increased, the rates of inactivation and injury became more and more similar.
Recovery of chill-stressed Vibrio parahaemolyticus from oysters with enrichment broths supplemented with magnesium and iron salts
Authors: Ma-Lin C F , Beuchat L R
Published: January 2020

The effects of magnesium and iron salts on the recovery and growth of chill-stressed cells of Vibrio parahaemolyticus were studied. Supplementation of glucose salt Teepol (GST) broth with 20 to 100 mM of Mg2+ significantly (P less than or equal to 0.05) increased the number of cells recovered from oyster homogenate stored at 3 degrees C. Populations detected with supplemented GST were comparable to those obtained with Horie arabinose ethyl violet (HAE) broth, with or without Mg2+. Recovery of V. parahaemolyticus from homogenates stored at -18 degrees C was also improved when enrichment broths supplemented with Mg2+ were used. Ferric iron (added as FeCl3) at 240 microM in GST and 240 or 960 microM in HAE significantly enhanced the extent of recovery of chilled cells. Ferrous iron was generally less effective. Teepol did not influence the growth of nonchilled cells, but significantly reduced the viable population in suspensions of chilled cells when used at a level of 0.4% in GST. The relatively high pH (9.0) of HAE caused a significant reduction in the number of viable, chill-stressed cells of V. parahaemolyticus. The overall results indicated that HAE broth is superior to GST for recovering V. parahaemolyticus from refrigerated and frozen oyster homogenates.
Enzymatic Synthesis of
l
-Carnitine by Reduction of an Achiral Precursor: the Problem of Reduced Nicotinamide Adenine Dinucleotide Recycling
Authors: Vandecasteele Jean-Paul
Published: January 2020

Synthesis of
l
-carnitine has been carried out by the enzymatic reduction of the carbonyl group of the achiral precursor 3-dehydrocarnitine with the oxidized nicotinamide adenine dinucleotide-linked carnitine dehydrogenase. Various enzymatic or chemical systems have been tested to regenerate the reduced nicotinamide adenine dinucleotide oxidized in the reduction of 3-dehydrocarnitine. Because of the instability of this compound in aqueous solutions, it was added by continuous feeding as a rate-limiting constituent in the reaction mixture. Under these conditions, conversion yields of 95% were achieved with the glucose plus glucose dehydrogenase system. A total number of 530 reduced nicotinamide adenine dinucleotide recyclings was obtained with this system for a production of 45 g of
l
-carnitine per liter. The stabilities of the oxidized nicotinamide adenine dinucleotide and the reduced nicotinamide adenine dinucleotide have been determined at various pH values. In view of these results, several possible strategies for enzymatic syntheses with the reduced nicotinamide adenine dinucleotide as a regenerable coenzyme are discussed.
Quantitative, radial diffusion slide assay for staphylocoagulase
Authors: Kohl J D , Johnson M G
Published: January 2020

A simple, quantitative radial diffusion assay for staphylocoagulase in culture fluids, using microscope slides coated with a thin layer of agar containing plasma and fibrinogen, was developed. No prior purification of the enzyme was needed, and only small quantities, 7 microliter, were required for each test. This method is particularly suitable for objectively comparing the relative amounts of coagulase produced by different cultures of Staphylococcus aureus.
Use of Two-Dimensional Polyacrylamide Gel Electrophoresis to Identify and Classify
Rhizobium
Strains
Authors: Roberts Gary P. , Leps Walter T. , Silver Lin E. , Brill Winston J.
Published: January 2020

Fifty-seven strains of various
Rhizobium
species were analyzed by two-dimensional gel electrophoresis. Since the protein pattern on such gels is a reflection of the genetic background of the tested strains, similarities in pattern allowed us to estimate the relatedness between these strains. All group II rhizobia (slow growing) were closely related and were very distinct from group I rhizobia (fast growing).
Rhizobium meliloti
strains formed a distinct group. The collection of
R. leguminosarum
and
R. trifolii
strains together formed another distinct group. Although there were some similarities within the
R. phaseoli
, sesbania rhizobia, and lotus rhizobia, the members within these seemed much more diverse than the members of the above groups. The technique also is useful to determine whether two unknown strains are identical.
Spore Load of
Ascosphaera
Species on Emerging Adults of the Alfalfa Leafcutting Bee,
Megachile rotundata
Authors: Vandenberg John D. , Fichter Becky L. , Stephen W. P.
Published: January 2020

The spore load of
Ascosphaera
species spores on larval chalkbrood cadavers and newly emergent adults of the alfalfa leafcutting bee,
Megachile rotundata
, was determined. The spore content of chalkbrood cadavers ranged from 3 × 10
6
to 5 × 10
8
. Adults emerging through zero to nine cadavers carried spores on all body parts examined by scanning electron microscopy. Estimates of the total number of spores obtained from a series of adult washes ranged from 9 × 10
4
to 8 × 10
7
. Some adult males which emerged through no cadavers carried 10
4
to 10
5
spores, indicating that nesting materials might also have been contaminated. However, the control of chalkbrood in commercial bee populations may not be accomplished simply by providing clean nesting materials as adults may still emerge through diseased larvae.
Hot Acidified Cupric Acetate Soaks for Eradication of
Xanthomonas campestris
from Crucifer Seeds
Authors: Schaad N. W. , Gabrielson R. L. , Mulanax M. W.
Published: January 2020

Acidified cupric acetate soaks were tested for eradication of
Xanthomonas campestris
from naturally infected crucifer seeds. The pathogen was eradicated from seeds by soaking in 0.5% cupric acetate dissolved in 0.005 N acetic acid for 20 min at 35, 40, 45, and 50°C but not 25°C. Moreover, normal bacterial flora of crucifer seeds and the seed-borne
Phoma lingam
and
Alternaria
spp. were reduced by 95, 92, and 81%, respectively, after the cupric acetate treatment at 40°C. The seed germination percentage was generally reduced, but the amount of reduction depended upon the treatment temperature and plant cultivar. At 50°C, less than 50% of the seed of all 12 cultivars tested germinated, whereas at 40°C more than 50% of the seeds of most cultivars germinated. Treating seeds in cupric acetate at 40°C should prove useful for eradicating
X. campestris
from seeds of breeding lines and stock seed used for hybrid seed production. Furthermore, a significant reduction in total bacterial flora and seed-borne fungi suggests the usefulness of the treatment for other microorganisms associated with other seeds or foodstuffs.
Virulence of cloned variants of Autographa californica nuclear polyhedrosis virus
Authors: Andrews R E , Spence K D , Miller L K
Published: January 2020

The relative virulence of five different genotypic variants of Autographa californica nuclear polyhedrosis virus was tested by determining the 50% lethal dose of occluded virus for larvae of Trichoplusia ni. The 50% lethal dose values of uncloned virus and the five cloned genotypic variants ranged between 10 and 21 polyhedra per larva, and no statistically significant differences were observed. Cloning has therefore neither enhanced nor decreased the virulence of this potential microbial pesticide.
Production of Aseptic Spores of Vesicular-Arbuscular Endophytes and Their Viability After Chemical and Physical Stress
Authors: Tommerup Inez C. , Kidby Denis K.
Published: January 2020

The survival of germinating spores of vesicular-arbuscular endophytes after treatments with oxidizing agents, antibiotics, moist heat, ultrasonic radiation, and ultraviolet radiation was compared with that of their contaminating microbes. Spores of three species were rapidly decontaminated by treatment with 0.42% (wt/vol) chlorine available from 5.0% (wt/vol) chloramine-T at 30°C for 20 to 40 min depending on the species and the soil from which they were extracted. This treatment did not change spore viability. The survival of spores was reduced by exposure for 20 min to 1.11% chlorine at 30°C for
Glomus caledonius
or at 35°C for
Acaulospora laevis
. Growth of any bacteria surviving treatment with oxidizing agents was inhibited by 100 μg of chloramphenicol per ml in agar; however, spore germination and germ tube growth were reduced only by concentrations greater than 200 μg/ml in agar. Spore germination was decreased by concentration of pimaracin, which controlled fungal growth. The spores survived moist heat at 40°C for 80 min, 55°C for 10 min, and 60°C for less than 1 min. The viability of spores was unaffected by ultrasonic irradiation for up to 4 min. Spores of
G. caledonius
and
A. laevis
were extremely resistant to ultraviolet radiation. Their viability was unaffected by exposure to 5 × 10
8
ergs cm
−2
from an ultraviolet source of 253.7nm. The spores had very thick, pigmented walls, and the possibility that these provided some protection against the physical and chemical treatments is discussed. The degree of physiological damage to the spores caused by the treatments demonstrated some adverse effects of basic laboratory procedures. This information, together with that on the comparative sensitivity of contaminating microbes to the treatments, was used in the development of protocol for producing large numbers of uncontaminated spores.
Isolation Method for Bacterial Isolates Capable of Growth on
p
-Chlorobiphenyl
Authors: Sylvestre Michel
Published: January 2020

A method is reported for screening for
p
-chlorobiphenyl (pCB)-degrading bacteria from various environments. A solid medium was inoculated with the sample to be analyzed, colonies were allowed to develop, and the plates were then sprayed with a pCB solution in ether. The positive colonies were recorded as those surrounded with a clear zone in the film of pCB. That these colonies were able to degrade pCB was shown by their ability to grow on pCB in liquid medium with concomitant disappearance of the substrate and by the appearance of colored compounds in cultures grown on pCB.
Degradation of melanin by Aspergillus fumigatus
Authors: Luther J P , Lipke H
Published: January 2020

A strain of Aspergillus fumigatus from composted coffee and garden wastes utilized natural deproteinized insect, banana, hair, octopus, and synthetic tyrosine and dopa melanins as sole sources of carbon. With a sucrose supplement, degradation was essentially complete after 50 days in Czapek medium pH 6.5 at 30 degrees C. The catabolic rate differed for each substrate pigment, as did the molecular weight distribution of products accumulating in the medium. After incubation with L-[U-14C]melanin, over 50% was recovered in a dark fungal pigment, the remainder appearing as cell protein, chitin, lipid, CO2, and polar metabolites. When grown on melanin, the normally pale mycelia darkened with the production of a fungal allomelanin, with infrared spectrum and alkali fusion products differing from those of the substrate pigment. Isotope distribution in amino acids for A. fumigatus grown on labeled melanin supplemented with sucrose suggested separate pools for synthesis of cell proteins and melanoproteins. Deposition of allomelanin increased resistance of conidia, sterigma, and conidiophores to lytic carbohydrases as judged by scanning electron microscopy.
R-Plasmid Transfer in
Zymomonas mobilis
Authors: Skotnicki Mary L. , Tribe David E. , Rogers Peter L.
Published: January 2020

Conjugal transfer of three IncP1 plasmids and one IncFII plasmid into strains of the ethanol-producing bacterium
Zymomonas mobilis
was obtained. These plasmids were transferred at high frequencies from
Escherichia coli
and
Pseudomonas aeruginosa
into
Z. mobilis
and also between different
Z. mobilis
strains, using the membrane filter mating technique. Most of the plasmids were stably maintained in
Z. mobilis
, although there was some evidence of delayed marker expression. A low level of chromosomal gene transfer, mediated by plasmid R68.45, was detected between
Z. mobilis
strains. Genetic evidence suggesting that
Z. mobilis
may be more closely related to
E. coli
than to
Pseudomonas
or
Rhizobium
is discussed.
Nutritional Interdependence Among Rumen Bacteria,
Bacteroides amylophilus, Megasphaera elsdenii
, and
Ruminococcus albus
Authors: Miura Hideki , Horiguchi Masaaki , Matsumoto Tatsuro
Published: January 2020

Nutritional interdependence among three representatives of rumen bacteria,
Bacteroides amylophilus, Megasphaera elsdenii
, and
Ruminococcus albus
, was studied with a basal medium consisting of minerals, vitamins, cysteine hydrochloride, and NH
4
+
.
B. amylophilus
grew well in the basal medium supplemented with starch and produced branched-chain amino acids after growth ceased. When cocultured with
B. amylophilus
in the basal medium supplemented with starch and glucose, amino acid-dependent
M. elsdenii
produced an appreciable amount of branched-chain fatty acids, which are essential growth factors for cellulolytic
R. albus
. A small addition of starch (0.1 to 0.3%) to the basal medium containing glucose and cellobiose brought about successive growth of the three species in the order of
B. amylophilus, M. elsdenii
, and
R. albus
, and successive growth was substantiated by the formation of branched-chain amino acids and fatty acids in the culture. Supplementation with 0.5% starch, however, failed to support the growth of
R. albus
. On the basis of these results, the effects of supplementary starch or branched-chain fatty acids on cellulose digestion in the rumen was discussed.
Alteration of Host Specificity to Lytic Bacteriophages in
Streptococcus cremoris
Authors: Sinha R. P.
Published: January 2020

A mutant of
Streptococcus cremoris
strain ML1 was isolated based on its resistance to acriflavine. The mutant strain showed resistance to the growth of virulent bacteriophages to which the parental strain was sensitive whereas it became sensitive to a number of other virulent phages to which the parental strain was resistant. At the same time, infection of the mutant strain by another bacteriophage sc607 resulted in killing of cells without production of progeny phages. The phage adsorption appeared normal, suggesting that the killing was a postadsorption event. Such killing of bacterial cells was prevented by chloramphenicol treatment, indicating that involvement of some protein either synthesized by phage or phage-induced cellular protein. Synthesis of ribonucleic acid was abruptly terminated after infection of the mutant strain by phage sc607 but not of the parental strain. The alteration of host specificity in the mutant to different lytic bacteriophages and especially abortive infection by phage sc607 resembles the prophage-mediated interference observed in other bacteria.
Regulation of Enzymes Associated with C-1 Metabolism in Three Facultative Methylotrophs
Authors: McNerney Thomas , O'Connor Mary L.
Published: January 2020

The levels of the oxidation enzyme methanol dehydrogenase and the serine pathway enzymes, hydroxypyruvate reductase, glycerate kinase, serine transhydroxymethylase, serine-glyoxylate aminotransferase, phosphoenolpyruvate carboxylase, and malyl-coenzyme A lyase, were studied in cells of the facultative methylotrophs
Pseudomonas
AM1,
Pseudomonas
3A2 and
Hyphomicrobium
X grown on different substrates. Induction and dilution curves for these enzymes suggest they may be regulated coordinately in
Hyphomicrobium
X, but not in
Pseudomonas
AM1 or 3A2. Glyoxylate stimulated the serine transhydroxymethylase activity in methanol-grown cells of all three organisms. A secondary alcohol dehydrogenase activity was detected at low levels in
Pseudomonas
AM1 and
Hyphomicrobium
X, but not in
Pseudomonas
3A2.
Concentration of poliovirus in water by molecular filtration
Authors: Berman D , Rohr M E , Safferman R S
Published: January 2020

The efficiency of concentrating poliovirus 1 from distilled water samples was determined by using a recirculating-flow molecular filtration system. The most efficient recoveries were achieved against members with a 10,000 nominal molecular weight limit pretreated with flocculated beef extract. This procedure yielded a mean virus recovery of 67%.
Nitrate Dissimilation Under Microaerophilic Conditions by a Magnetic Spirillum
Authors: Escalante-Semerena J. C. , Blakemore Richard P. , Wolfe R. S.
Published: January 2020

During microaerophilic growth of magnetic spirillum MS-1 on tartrate and nitrate, a maximal cell density was obtained at an initial oxygen partial pressure of 17 Pa. A transient accumulation of nitrous oxide and a 1:2 (mol/mol) stoichiometry between tartrate oxidation and nitrate reduction were observed, indicating that the organism carried out a respiratory type of metabolism.
Role of Microorganisms in the Consumption and Production of Atmospheric Carbon Monoxide by Soil
Authors: Conrad Ralf , Seiler Wolfgang
Published: January 2020

Consumption and production of atmospheric CO was measured under field conditions in three different types of soil. CO was consumed by an apparent first-order reaction and produced by an apparent zero-order reaction, resulting in a dynamic equilibrium with the consumption of atmospheric CO as the net reaction. CO consumption was higher in summer than in winter. Laboratory experiments on five different soil types showed that CO consumption was strongly inhibited by the presence of streptomycin or cycloheximide (Actidione), or both. Thus, eucaryotic as well as procaryotic microorganisms were apparently responsible for the observed CO consumption. The aerobic carboxydobacterium
Pseudomonas carboxydovorans
added to sterile soil was able to utilize the low amounts (ca. 0.7 ppmv) of CO present in laboratory air. CO was consumed by soil under aerobic as well as anaerobic conditions. Anaerobic preincubation of the soil stimulated the anaerobic CO consumption and reduced the aerobic CO consumption. In contrast to CO consumption, CO production was stimulated by autoclaving, by ultraviolet-irradiation, by fumigation with NH
3
or CHCl
3
, by treatment with streptomycin or cycloheximide or both, by addition of NaCN, NaN
3
, or Na
2
HAsO
4
(or all three) in the presence of glucose under an atmosphere of pure oxygen, or by a drying and rewetting procedure. The consumption of atmospheric CO by soil is a microbial process, but the production of CO is apparently not a metabolic process.
Inhibition of the glycogen phosphorylase system during ochratoxicosis in chickens
Authors: Warren M F , Hamilton P B
Published: January 2020

Graded doses of ochratoxin A incorporated into the diet (0, 0.5, 1.0, 2.0, 4.0, and 8.0 micrograms/g) of broiler chickens significantly (P < 0.05) inhibited activity of protein kinase, the initiator enzyme of the glycogen phosphorylase system, in the livers at all dose levels. Only the highest dose, 8.0 micrograms/g, significantly reduced the total activity of phosphorylase kinase, which is activated by protein kinase. The total activity of phosphorylase, which is activated by phosphorylase kinase, was unaltered by ochratoxin A at any level. Additon of ochratoxin A to liver extracts control birds inhibited protein kinase but not phosphorylase kinase. When added to extracts of livers from control birds, cyclic adenosine 3',5'-monophosphate stimulated protein kinase but not phosphorylase kinase. The cyclic adenosine 3',5'-monophosphate had no effect when added to extracts from birds fed ochratoxin A. These results suggest that ochratoxin A affects primarily the cyclic adenosine 3',5'-monophosphate-dependent protein kinase which initiates the enzymatic cascade leading to glycogenolysis. Furthermore, these results conform an earlier assignment on morphological criteria of the glycogenosis of ochratoxicosis as a type X glycogen storage disease.
Fine Structure of Extracellular Polysaccharide of
Erwinia amylovora
Authors: Politis D. J. , Goodman R. N.
Published: January 2020

Virulent E
9
and avirulent E
8
strains of
Erwinia amylovora
were shown by means of light, transmission, and scanning microscopy to be, respectively, encapsulated and unencapsulated. Difficulty was encountered in stabilizing the fibrillar-appearing capsular extracellular polysaccharide. We suggest that the ephemeral nature of extracellular polysaccharide is due to the collapse of its extended structure upon dehydration. This occurs when bacteria are prepared for either transmission or scanning electron microscopy. The electron micrographs support our previous biochemical and immunological studies contending that the capsule is composed of tightly bound and loosely held components. The preparation of bacteria in freeze-dried colonies has permitted us to observe and explain the fluidity of the encapsulated strain. We suggest that this fluidity is a reflection of the loosely held extracellular polysaccharide or slime.
Association of methanogenic bacteria with rumen ciliates
Authors: Vogels G D , Hoppe W F , Stumm C K
Published: January 2020

In 11 species of rumen ciliates belonging to nine genera of the family Ophryoscolecidae (order Entodiniomorphida) an ectosymbiosis with methanogenic bacteria was found. The bacteria could be identified as methanogens on the basis of the presence of specific fluorescent coenzymes (F350 and F420). This somatic interaction may reflect a metabolic interaction in which efficient interspecies hydrogen transfer benefits both partners.
Laboratory studies of disinfectants against Legionella pneumophila
Authors: Skaliy P , Thompson T A , Gorman G W , Morris G K , McEachern H V , Mackel D C
Published: January 2020

Legionella pneumophila suspended in tap water was exposed to biocides recommended for inhibiting biological growth in cooling towers and evaporative condensers of air-conditioning systems. Chlorine, 2,2-dibromo-3-nitrilopropionamide, and a compound containing didecyldimethylammonium chloride and isopropanol were effective in destroying concentratiois of 10(5) to 10(6) viable cells per ml. Formulations consisting of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one, disodium ethylene bis(thiocarbamate) and sodium dimethyl dithiocarbamate, and a phenolic with pentachlorophenate and sodium salts of other chlorophenols were less effective.
Microbial transformations of natural antitumor agents: use of solubilizing agents to improve yields of hydroxylated ellipticines
Authors: Chien M M , Rosazza J P
Published: January 2020

Aromatic hydroxylation of the antitumor alkaloid ellipticine by Aspergillus alliaceus results in the formation of both 8- and 9-hydroxyellipticines. Experiments designed to increase yields of microbial hydroxylation focused on enhancing the water solubility of ellipticine in aqueous fermentation media by use of wetting agents or solubilizing polymers, or both. Yields of hydroxylated metabolites were determined by high-performance liquid chromatography with the use of a mu-Bondapak-phenyl column and a mobile phase of acetonitrile--0.1% (NH4)2CO3 (1:1). Polyvinylpyrrolidone (molecular weight, 40,000) and polyoxyethylated vegetable oil (Emulphor 620) increased the water solubility of ellipticine and the yield of hydroxylated metabolites.
Negative enrichment procedure for isolation of Legionella pneumophila from seeded cooling tower water
Authors: Thorpe T C , Miller R D
Published: January 2020

A negative enrichment procedure was developed which was capable of isolating Legionella pneumophila directly from seeded air-conditioning cooling tower water onto laboratory media. This procedure was based on an 8-h incubation under conditions that were bactericidal to the indigenous water microflora but merely bacteriostatic to L. pneumophila.
Rocket Immunoelectrophoresis of the Entomocidal Parasporal Crystal of
Bacillus thuringiensis
subsp.
kurstaki
Authors: Andrews R. E. , Iandolo J. J. , Campbell B. S. , Davidson L. I. , Bulla L. A.
Published: January 2020

Rocket immunoelectrophoresis was used to quantitate the soluble parasporal crystal of
Bacillus thuringiensis
subsp.
kurstaki.
The method described is rapid, reliable, specific, and extremely accurate, and it can be used to measure crystal toxin in commercial microbial insecticides that contain a mixture of spores, vegetative cells, and carrier materials.
Non-immunological precipitation by the neutral detergent triton X-100 in agar gel diffusion
Authors: Mansheim B J , Stenstrom M L
Published: January 2020

Triton X-100 can be used to clarify vague immunoprecipitin lines from bacterial antigens; however, non-immunological precipitation can lead to mistaken interpretation of immunodiffusion results. If Triton X-100 is added directly to the gel during preparation rather than to the antigen well, this detergent artifact can be eliminated.
Bacterial Density in Water Determined by Poisson or Negative Binomial Distributions
Authors: El-Shaarawi A. H. , Esterby S. R. , Dutka B. J.
Published: January 2020

The question of how to characterize the bacterial density in a body of water when data are available as counts from a number of small-volume samples was examined for cases where either the Poisson or negative binomial probability distributions could be used to describe the bacteriological data. The suitability of the Poisson distribution when replicate analyses were performed under carefully controlled conditions and of the negative binomial distribution for samples collected from different locations and over time were illustrated by two examples. In cases where the negative binomial distribution was appropriate, a procedure was given for characterizing the variability by dividing the bacterial counts into homogeneous groups. The usefulness of this procedure was illustrated for the second example based on survey data for Lake Erie. A further illustration of the difference between results based on the Poisson and negative binomial distributions was given by calculating the probability of obtaining all samples sterile, assuming various bacterial densities and sample sizes.
Effect of Dietary Monensin or Chlortetracycline on Methane Production from Cattle Waste
Authors: Varel V. H. , Hashimoto A. G.
Published: January 2020

Wastes from feedlot cattle fed finishing diets containing either monensin, chlortetracycline, or no antibiotic were investigated as substrates for methane production. We used continuously mixed anaerobic fermentors with 3-liter working volumes at 35 and 55°C; these fermentors were fed once per day. Within a few days after waste from animals fed monensin was added, the volume of methane produced began to decrease in the 55°C fermentors. After 9 days of daily feeding, methane production was severely inhibited, the pH dropped from 7.6 to 5.9, and the concentration of volatile acids increased from 543 to 6,300 mg/liter (as acetate). Although additions of waste from cattle fed monensin were discontinued after 9 days, the fermentors did not resume gas production within 8 weeks. The addition of waste from cattle which had been fed chlortetracycline reduced the methane production rate approximately 20%; however, pH and volatile acid values were comparable to control fermentor values after 40 days. Similar effects were observed with the 35°C fermentors. In a batch fermentation experiment in which 50-g portions of volatile solids from waste of animals fed monensin, chlortetracycline, or no antibiotics were added to fermentors, monensin delayed the onset of methane production for about 40 days, but then these fermentors began to produce methane at a rate comparable to the control rate. The ultimate methane yields from the three types of waste after 180 days were not significantly different. These studies indicate that monensin has a detrimental effect on the conversion of feedlot wastes to methane, unless microorganisms can be adapted to the levels that are present in these wastes.
Recovery of coliphages from wastewater effluents and polluted lake water by the magnetite-organic flocculation method
Authors: Bitton G , Chang L T , Farrah S R , Clifford K
Published: January 2020

A magnetite-organic flocculation method was developed for the concentration of coliphages from wastewater effluents and polluted lake water. A high percent (68 to 100%) recovery of coliphages from sewage effluents was achieved by this procedure. Coliphage recovery from Lake Alice, a sewage-contaminated lake, showed phage concentrations ranging from 2.3 X 10(2) to 1.9 X 10(3) plaque-forming units per liter. This method is simple and inexpensive and may be carried out under field conditions.
Anaerobic Oxidation of Acetylene by Estuarine Sediments and Enrichment Cultures
Authors: Culbertson Charles W. , Zehnder Alexander J. B. , Oremland Ronald S.
Published: January 2020

Acetylene disappeared from the gas phase of anaerobically incubated estuarine sediment slurries, and loss was accompanied by increased levels of carbon dioxide. Acetylene loss was inhibited by chloramphenicol, air, and autoclaving. Addition of
14
C
2
H
2
to slurries resulted in the formation of
14
CO
2
and the transient appearance of
14
C-soluble intermediates, of which acetate was a major component. Acetylene oxidation stimulated sulfate reduction; however, sulfate reduction was not required for the loss of C
2
H
2
to occur. Enrichment cultures were obtained which grew anaerobically at the expense of C
2
H
2
.