bluuebunny/crossref_metadata_2025 huggingface dataset:
Poliovirus retention in 75-cm soil cores after sewage and rainwater application
Authors: Landry E F , Vaughn J M , Penello W F
Published: January 2020

The adsorption rate of a guanidine-resistant strain of poliovirus LSc 2ab was measured in Long Island soils with in situ field cores (10.1 by 75 cm). The test virus was chosen because it exhibited soil adsorption and elution characteristics of a number of non-polioviruses. After the inoculation of cores with seeded sewage effluent at a 1-cm/h infiltration rate, cores were extracted, fractionated, and analyzed for total plaque-forming units per each 5-cm fraction. The results showed that 77% of the viruses were adsorbed in the first 5 cm of soil. An additional 11% were found in the 5- to 10-cm fraction, and a total of 96% of the viruses were adsorbed by 25 cm. The remaining 4% were uniformly distributed over the next 50 cm of soil, with a minimum of 0.23% in each soil section. Few viruses (< 0.22%) were observed in core filtrates. Analysis of the viral distribution pattern in seeded cores, after an application of a single rinse of either sewage effluent or rainwater, indicated that large-scale viral mobilization was absent. However, localized areas of viral movement were noted in both of the rinsed cores, with the rainwater-rinsed cores exhibiting more expensive movement. All mobilized viruses were resorbed at lower core depths.
Production of Nitrous Oxide by Ammonia-Oxidizing Chemoautotrophic Microorganisms in Soil
Authors: Blackmer A. M. , Bremner J. M. , Schmidt E. L.
Published: January 2020

Gas chromatographic studies showed that nitrous oxide was produced in each instance when sterilized (autoclaved) soil was incubated after treatment with ammonium sulfate and inoculation with pure cultures of ammonia-oxidizing chemoautotrophic microorganisms (strains of
Nitrosomonas, Nitrosospira
, and
Nitrosolobus
). Production of N
2
O in ammonium-treated sterilized soil inoculated with
Nitrosomonas europaea
increased with the concentration of ammonium and the moisture content of the soil and was completely inhibited by both nitrapyrin and acetylene. Similar effects of nitrapyrin, acetylene, ammonium concentration, and soil moisture content were observed in studies of factors affecting N
2
O production in nonsterile soil treated with ammonium sulfate. These observations support the conclusion that, at least under some conditions, most of the N
2
O evolved from soils treated with ammonium or ammonium-producing fertilizers is generated by chemoautotrophic nitrifying microorganisms during oxidation of ammonium to nitrite.
Scanning Electron Microscopy of
Rhizobium trifolii
Infection Sites on Root Hairs of White Clover
Authors: Higashi Shiro , Abe Mikiko
Published: January 2020

White clover root hairs which were inoculated with
Rhizobium trifolii
4S (infectious strain) contained infection threads which were observed by light microscopy and scanning electron microscopy. Three morphological types of root hairs retaining infection threads were recognized. The bacteria were strongly attached between the surfaces of two plant cell walls as follows: between surfaces of a root hair tip curled back on itself, between a protuberance from a root hair and its cell surface, or between two root hair tips clinging together. An anatomical analysis documented the attachment site of the infection thread sheath from the inside of the root hair cell.
New medium for isolating propionibacteria and its application to assay of normal flora of human facial skin
Authors: Kishishita M , Ushijima T , Ozaki Y , Ito Y
Published: January 2020

The conditions for isolation and cultivation of Propionibacterium acnes and related propionibacteria were studied in detail. Triton X-100 added to the diluent inhibited the growth of propionibacteria in concentrations of 0.05 to 0.1%. However, such was not the case with Tween 80; rather, growth of the bacteria was further enhanced by this agent. Consequently, Tween 80 was considered to be a suitable surfactant for addition to the diluent for isolation of propionibacteria. A new medium for isolating propionibacteria from human skin was developed. Comparative studies with colonies of P. acnes, Propionibacterium granulosum, and Staphylococcus epidermidis showed morphological differences among the colonies; thus, the medium was very useful for differentiating and identifying species of the microbes. The new medium was used for studies on the distribution of propionibacteria on the foreheads of 30 Japanese volunteers. Among 447 strains of P. acnes and 86 strains of P. granulosum isolated from the volunteers, all strains of the former were positive for indole, nitrate, milk, and gelatin hydrolysis, whereas all strains of the latter were negative for all of the tests.
Growth of cholesterol-reducing Eubacterium on cholesterol-brain agar
Authors: Brinkley A W , Gottesman A R , Mott G E
Published: January 2020

An agar medium containing 5% cholesterol has been developed for the isolation, enumeration, and characterization of cholesterol-reducing strains of Eubacterium.
Distribution of beta-glucanases within the genus Bacillus
Authors: Martin D F , Priest F G , Todd C , Goodfellow M
Published: January 2020

Representative strains (368) from 36 species in the genus Bacillus were screened for the secretion of beta-glucanases. (1 leads to 6)-beta-glucanases active on pustulan were produced by a minority of the organisms studied (4%), but (1 leads to 3)-beta-glucanases which hydrolyzed laminarin and pachyman were more widespread and were secreted by 56 and 44% of the strains, respectively.
Cellulose Degradation by Cellulose-Clearing and Non-Cellulose-Clearing Brown-Rot Fungi
Authors: Highley Terry L.
Published: January 2020

Cellulose degradation by four cellulose-clearing brown-rot fungi in the
Coniophoraceae—Coniophora prasinoides, C. puteana, Leucogyrophana arizonica
, and
L. olivascens
—is compared with that of a non-cellulose-clearing brown-rot fungus,
Poria placenta
. The cellulose- and the non-cellulose-clearing brown-rot fungi apparently employ similar mechanisms to depolymerize cellulose; most likely a nonenzymatic mechanism is involved.
Virus removal during groundwater recharge: effects of infiltration rate on adsorption of poliovirus to soil
Authors: Vaughn J M , Landry E F , Beckwith C A , Thomas M Z
Published: January 2020

Studies were conducted to determine the influence of infiltration rate on poliovirus removal during groundwater recharge with tertiary-treated wastewater effluents. Experiments were conducted at a uniquely designed, field-situated test recharge basin facility through which some 62,000 m3 of sewage had been previously applied. Recharge at high infiltration rates (75 to 100 cm/h) resulted in the movement of considerable numbers of seeded poliovirus to the groundwater. Moderately reduced infiltration rates (6 cm/h) affected significantly improved virus removal. Very low infiltration rates (0.5 to 1.0 cm/h), achieved by partial clogging of the test basin, yielded the greatest virus removal efficiencies.
Persistence of Clostridium botulinum type B on a cattle farm after an outbreak of botulism
Authors: Notermans S , Dufrenne J , Oosterom J
Published: January 2020

On farms involved in botulism outbreaks, cycles of Clostridium botulinum have occurred. The cycles were initiated by feeding brewers' grains contaminated with proteolytic C. botulinum type B to the cows. Spreading of manure containing feces of these cows increased the contamination of the pastures. In grass silages prepared with wilted grass from these pastures the number of C. botulinum type B organisms increased, and toxin type B was produced. Feeding cows with the contaminated silage fodder completed the cycle. Besides contamination of human foodstuffs (milk and meat), further contamination of the environment occurred. It was demonstrated that fowl may be important vectors in spreading C. botulinum.
High Production of β-Glucosidase in
Schizophyllum commune
: Isolation of the Enzyme and Effect of the Culture Filtrate on Cellulose Hydrolysis
Authors: Desrochers M. , Jurasek L. , Paice M. G.
Published: January 2020

Optimization experiments with response surface statistical analysis were performed with
Schizophyllum commune
to obtain high β-glucosidase yields. The factors in the optimization experiment were the concentrations of cellulose, peptone, and KH
2
PO
4
. Their optimal values were 3.2, 3.0, and 0.2 g/100 ml, respectively. Enzyme assays revealed very high β-glucosidase (22.2 U/ml) and cellobiase (68.9 U/ml) yields. The avicelase yield was low as compared with that from
Trichoderma reesei
. Mixtures of
S. commune
and
T. reesei
culture filtrates caused faster and more extensive saccharification of Avicel than could be achieved by either filtrate alone. A β-glucosidase was isolated and purified from the optimized culture filtrate of
S. commune
. The electrophoretic mobility of the purified β-glucosidase indicated a molecular weight of 97,000. The amino acid composition was similar to that of β-glucosidase from
T. reesei
. The acidic (aspartate and glutamate) residues or their amides or both made up approximately 20% of the protein. The NH
2
-terminal amino acid of the enzyme was histidine.
Susceptibility of Legionella pneumophila to three cooling tower microbicides
Authors: Grace R D , Dewar N E , Barnes W G , Hodges G R
Published: January 2020

Investigation of epidemic outbreaks of Legionnaires disease by Center for Disease Control personnel has resulted in the isolation of Legionella pneumophila from water in the air-conditioning cooling towers or evaporative condensers at the site of the outbreak. It is suspected that improperly maintained open, recirculating water systems may play a role in the growth and dissemination of this pathogen. The objective of this study was to determine the antimicrobial activity of three chemically different, commercially available, cooling tower microbicides against L. pneumophila. Using two in vitro test systems, a combination of N-alkyl dimethyl benzyl ammonium chloride and bis (tri-n-butyltin) oxide was found to kill L. pneumophila at a concentration 25 times less than the minimum recommended use concentration, whereas N-alkyl 1,3-propanediamine and methylene bis (thiocyanate) were active at concentrations equal to or greater than the concentrations recommended for use by the manufacturer.
Symbiotic Utilization of Polyvinyl Alcohol by Mixed Cultures
Authors: Sakazawa Chikahiro , Shimao Masayuki , Taniguchi Yoshifumi , Kato Nobuo
Published: January 2020

Polyvinyl alcohol (PVA)-utilizing cultures were obtained from various sources. They were mixed cultures even after cyclical transfer to liquid and plate media with PVA as a sole source of carbon. Component bacteria were isolated from the several mixed cultures, and it was shown that PVA was utilized symbiotically by two bacterial members which could not utilize PVA in each respective pure culture. From a mixed culture, strains VM15, VM15A (
Pseudomonas putida
) and VM15C (
Pseudomonas
sp.) were isolated as members essential for PVA utilization. VM15C was the predominant strain in the mixed-culture population and produced PVA-degrading enzyme. The culture supernatant of VM15A enabled VM15C to grow on PVA. VM15A was presumed to supply VM15C with a unique growth stimulant which was distinct from usual growth factors.
Formation of Bacterial Microcolonies on Feed Particles in the Rumen
Authors: Cheng K. -J. , Fay J. P. , Coleman R. N. , Milligan L. P. , Costerton J. W.
Published: January 2020

Examination of particulate feed that had been digested in vivo in the rumen, and of the leaves of specific legumes that had been digested in vitro by a mixed population of rumen bacteria, showed that very extensive glycocalyx-enclosed bacterial microcolonies developed on many of the available surfaces. Some of these adherent bacteria colonized a surface almost exclusively and attracted another specific type of bacteria as the second members of a distinct morphological consortium. The true extent of the exopolysaccharide glycocalyces of these adherent rumen bacteria was seen in cases where the fibers were attached at multiple points, and their role in microcolony formation and adhesion could be unequivocally ascribed.
Enterotoxin formation by Clostridium perfringens type A in a defined medium
Authors: Labbe R G
Published: January 2020

Enterotoxin was produced by 9 of 10 strains of Clostridium perfringens type A when grown in a defined medium. Additional dextrin increased the amount of enterotoxin in extracts of sporulating cells of strain NCTC 10239.
Flocculants for Recovery of Food-Borne Viruses
Authors: Kostenbader Kenneth D. , Cliver Dean O.
Published: January 2020

The procedure described permits comparison of polyelectrolytes for their ability to flocculate food solids and thus enable filtration for recovery of food-borne viruses.
Survival of clostridial spores in animal tissues
Authors: Gill C O , Penney N , Wauters A M
Published: January 2020

Spores injected intravenously into mice in numbers in excess of 10(2)/g of body weight were initially dispersed to most organs, but after a few days the remaining spores were concentrated in the liver, from which they were eliminated with a half-life of about 6 days. Intraperitoneal injection did not result in contamination of organs unless initial spore numbers exceeded 10(5)/g of body weight, in which case the spores behaved in the same manner as those injected intravenously. Oral administration of spores did not result in any contamination of tissues.
Incidence of Yersinia enterocolitica in raw milk in eastern France
Authors: Vidon D J , Delmas C L
Published: January 2020

A total of 75 raw milk samples collected from a central dairy or from retailers in Alsace, France, were analyzed for the presence of Yersinia enterocolitica. Three procedures were used: enrichment at 4 degrees C for 1 month; enrichment in modified Rappaport medium at room temperature for 72 h after a preenrichment at 4 degrees C for 1 month; and enrichment in a new medium containing sucrose, tris(hydroxymethyl)aminomethane, sodium azide, and ampicillin (PSTA) at 28 degrees C for 48 h after a preenrichment at 4 degrees C for 1 month. Isolation of Y. enterocolitica was made on Hektoen medium plus ampicillin. Sixty-one samples were positive (81.4%), but the PSTA medium produced the greatest number of isolates. Biochemical, serological, and phage typing of 40 isolates showed that chemotype 1 and serogroup O:5 were predominant. In seven cases, two different strains were obtained from the same samples. Most of the 66 isolates tested for their antimicrobial susceptibility were resistant to ampicillin and carbenicillin, and all were sensitive to tetracycline, chloramphenicol, streptomycin, sulfonamides, and mercuric ions.
Growth Inhibition of
Streptomyces
Species by
l
-Serine and Its Effect on Tetracycline Biosynthesis
Authors: Parada Jose L.
Published: January 2020

The addition of serine to minimal medium inhibited the growth of
Streptomyces aureofaciens
and
Streptomyces rimosus.
Both the outgrowth of spores and the growth of vegetative cells were inhibited by
l
-serine. This effect was independent of the carbon source used. In rich nutrient medium, however, the serine effect was not observed. The presence of glycine and methionine in minimal medium reversed the growth inhibition imposed by serine, suggesting that a metabolic block related to the synthesis of these two amino acids was involved. A serine-tolerant mutant of
S. aureofaciens
isolated after ultraviolet irradiation showed a level of serine deaminase comparable to that of the wild-type strain, which indicated that tolerance to serine was not due to the presence of a more active deaminating enzyme in the mutant. Serine markedly reduced tetracycline and oxytetracycline biosynthesis with the parental strains of
Streptomyces
spp. The serine-tolerant mutant, however, produced almost the same amount of tetracycline in the presence or absence of serine. The final cell population in fermentation broth was not significantly reduced by
l
-serine, and the addition of glycine and methionine did not increase the tetracycline yields, which suggested that
l
-serine inhibition of antibiotic biosynthesis was by a mechanism different from that related to growth inhibition.
Levels of coenzyme F420, coenzyme M, hydrogenase, and methylcoenzyme M methylreductase in acetate-grown Methanosarcina
Authors: Baresi L , Wolfe R S
Published: January 2020

Methanosarcina barkeri strain 227 maintained on an acetate medium for 2 years was found to possess hydrogenase, methylcoenzyme M methylreductase, coenzyme F420, and coenzyme M. The levels of these constituents in acetate-grown cells were similar to those found in cells of the same strain grown on methanol or hydrogen and carbon dioxide.
Fungicide Enhancement of Nitrogen Fixation and Colonization of
Phaseolus vulgaris
by
Rhizobium phaseoli
Authors: Lennox Linda B. , Alexander Martin
Published: January 2020

The number and weight of pods and the weight and nitrogen content of the tops of beans (
Phaseolus vulgaris
) derived from seeds inoculated with a thiram-resistant strain of
Rhizobium phaseoli
were increased if the seeds were treated with thiram before sowing in soil. A greater percentage of the nodules on 21-day-old plants were derived from the resistant strain, more nodules were formed, and these nodules were more effective in the presence of the fungicide than in its absence. These differences in nodule numbers were no longer present in 56-day-old plants, and only a small percentage of the nodules contained the resistant strain. The abundance of the fungicide-tolerant
R. phaseoli
increased rapidly soon after planting the seed and subsequently fell markedly, but the rate of decline was less if the seeds had been treated with the chemical. Protozoa also proliferated if thiram had not been applied to the seed, but their numbers were deleteriously influenced by thiram.
Bdellovibrio
, bacteriophages, and lytic micro-organisms acting on
R. phaseoli
were rare under these conditions. Ciliates and flagellated protozoa were initially suppressed by planting thiram-coated bean seeds in nonsterile soil, but the former were inhibited longer than the latter and the ciliate numbers never fully recovered if the seeds were treated with the fungicide. The resistant strain grew well in sterile soil also inoculated with a protozoa-free mixture of soil microorganisms whether thiram was added or not, but after an initial rise in numbers, its abundance fell if the mixture contained protozoa; the rate of this fall was delayed by the fungicide. The numbers of
R. phaseoli
were consistently less in sterile soil inoculated with the rhizobium plus a mixture of soil microorganisms containing ciliates and other protozoa than if the inoculum contained other protozoa but no ciliates. These results suggest that a suppression of protozoa, and possibly especially the ciliates, accounts for the enhanced growth of beans and the greater initial frequency of nodules formed by the thiram-resistant
R. phaseoli
in the presence of this fungicide. Thiram applied to uninoculated seed enhanced bean growth if thiram-resistant
R. phaseoli
were present in soil.
Combined effects of solutes and food preservatives on rates of inactivation of and colony formation by heated spores and vegetative cells of molds
Authors: Beuchat L R
Published: January 2020

The combined and independent effects of sucrose, sodium chloride, potassium sorbate, and sodium benzoate on heat inactivation of conidia of Aspergillus flavus and Penicillium puberulum, ascospores of Byssochlamys nivea, and vegetative cells of Geotrichum candidum were studied. In addition, the effects of solutes and preservatives on colony formation by unheated and heated conidia of A. flavus were evaluated. Increased concentrations of sucrose were accompanied by increased tolerance to heat by A. flavus, B. nivea, and G. candidum. Low concentrations (3 and 6%) of sodium chloride protected A. flavus and G. candidum, whereas up to 12% sodium chloride protected B. nivea, but had little effect on the heat stability of P. puberulum. Potassium sorbate and sodium benzoate acted synergistically with heat to inactivate all four molds. At the same concentration, the two preservatives had varied degrees of effectiveness on molds and were influenced by the type of solute in the heating menstrua. Heated conidia of A. flavus had increased sensitivity to preservatives and reduced water activity, whether achieved by the presence of sucrose or sodium chloride, thus demonstrating heat-induced injury. At the same concentration, potassium sorbate was clearly more inhibitory than was sodium benzoate to colony formation by A. flavus, and the presence of sucrose and sodium chloride enhanced this inhibition.
Production and characterization of aflatoxin B2a antiserum
Authors: Gaur P K , Lau H P , Pestka J J , Chu F S
Published: January 2020

The specificity and sensitivity of antiserum elicited from rabbits against aflatoxin B2a-bovine serum albumin conjugates were characterized with a radioimmunoassay (RIA) and an enzyme-linked immunosorbent assay (ELISA). Aflatoxin B1 was first converted to aflatoxin B2a and then conjugated to bovine serum albumin and horseradish peroxidase by a reductive alkylation method. The antiserum was developed in New Zealand white rabbits by multiple-site injection with the aflatoxin B2a-bovine serum albumin conjugate. Antibody titers were determined by both RIA and ELISA. Competitive RIAs with various aflatoxin analogs indicated that the antiserum was most reactive with aflatoxin B1 and slightly cross-reactive with aflatoxins B2a, B2, and M1. Competitive ELISAs showed the antiserum to be equally specific for aflatoxins B2a and B12 and less reactive with aflatoxins B2 and M1. The relative sensitivities of RIA and ELISA for aflatoxin B1 quantitation were 100 and 10 pg per assay, respectively.
Method for measuring dissolved hydrogen in anaerobic ecosystems: application to the rumen
Authors: Robinson J A , Strayer R F , Tiedje J M
Published: January 2020

A method of transferring dissolved H2 to a CO2 headspace and then absorbing out the CO2 to concentrate the H2 before gas chromatographic analysis was developed to measure low concentrations of dissolved H2. A detection limit of 10 pmol of H2 ml-1 of water was achieved. When used ot monitor H2 changes in a bovine rumen, a 10-fold increase in H2 was noted 1 h after feeding and then declined rapidly to the normal steady-state concentration of 1 microM.
Biotransformation of aflatoxin B1 and its conjugated metabolites by rat gastrointestinal microfloras
Authors: Wei C , Macy J M , Hsieh D P
Published: January 2020

Rat cecal microflora from high- and low-fiber-fed animals hydrolyzed aflatoxin conjugates to metabolites indistinguishable from aflatoxin B1 and aflatoxin P1, but aflatoxicol was not a transformation product.
Sensitivity to avian purified protein derivative in cattle from farms having a high prevalence of swine mycobacteriosis
Authors: Brown J , McDaniel H T , Hornsby P S , Dreesen D W
Published: January 2020

On two farms in North Georgia a large percentage of the swine was infected with organisms of the Mycobacterium avium-intracellulare-scrofulaceum complex. The hypothesis that the cattle on these farms, which are maintained separately from the swine, would not be sensitive to avian purified protein derivative was rejected. It was concluded that the source of the M. avium-intracellulare-scrofulaceum complex of each animal population is environmental.
Pectinase Activity of Anaerobic and Facultatively Anaerobic Bacteria Associated with Soft Rot of Yam (
Diascorea rotundata
)
Authors: Obi Samuel K. C.
Published: January 2020

Anaerobic and facultatively anaerobic bacteria associated with soft rot of yam (
Diascorea rotundata
) were isolated by the looping-out method and found to consist of
Clostridium
(three isolates),
Corynebacterium
(three isolates),
Vibrio
(one isolate), and
Bacillus lentus
(one isolate). Enzyme assay for hydrolase, lyase, and pectinesterase activities by the cup-plate method showed that except for
Vibrio
sp.,
B. lentus
, and two isolates of
Corynebacterium
no pectinase activity could be detected for organisms cultured on pectin medium. Most of the cultures on yam tissue, however, showed activities for the three enzymes. The viscometric assay for hydrolase and lyase enzymes indicated a significant level of hydrolase activity (a 40.90% decrease in viscosity for
Vibrio
sp. and
Corynebacterium
spp.), but no lyase activity for most of the isolates. Two isolates of
Corynebacterium
and
B. lentus
caused changes in fresh yams suggestive of soft rot.
Antibiotic resistance and R-plasmids in food chain Salmonella: evidence of plasmid relatedness
Authors: Bezanson G S , Pauzé M , Lior H
Published: January 2020

A large number of strains (1,783) belonging to 15 Salmonella serovars isolated, in Canada, from the three major links of the human food chain were screened for multiple antibiotic resistance and the presence of R-plasmids. Multiresistant strains occurred among animal feed, livestock, and human isolates at frequencies of 4, 22, and 14%, respectively. Conjugation analysis revealed that 58% of the isolates from feeds, 87% of those from livestock, and 89% of the human strains carried all or part of their resistance determinants extrachromosomally on R-plasmids. Conjugative plasmids representing nine different incompatibility groups were detected, with the Inc I alpha group being predominant. Within the limits of the parameters measured, certain of these plasmids show a degree of relatedness suggestive of a common ancestry.
Fate of the Benzene Ring of Linear Alkylbenzene Sulfonate in Natural Waters
Authors: Larson R. J. , Payne A. G.
Published: January 2020

The biodegradability of linear alkylbenzene sulfonate (LAS) was studied in water samples collected from a receiving stream at locations above and below the discharge of a municipal wastewater treatment plant. Rates of primary biodegradation were determined for a commercial LAS mixture by a modified methylene blue-active substance method. Rates of LAS ultimate degradation were determined by radiochemical methods, using a C
12
LAS homolog uniformly labeled with
14
C in the benzene ring. The C
12
LAS was tested at low concentrations (50 and 500 μg/liter) comparable to those existing in the receiving stream. Loss of methylene blue-active substance response over time occurred rapidly in water samples containing sediment collected from below the treatment plant, with an estimated half-life for LAS of 0.23 days. Evolution of
14
CO
2
during mineralization of the benzene ring occurred rapidly in the same samples, with a half-life for the benzene ring of 0.73 day. Mineralization of the benezene ring was also observed in river water containing no sediments and in river water and sediment samples collected from above the treatment plant. However, the rate of degradation was reduced in these cases, with half-lives for ring carbon ranging from 1.4 to 14 days. Although LAS degradation was enhanced in the presence of sediments, adsorption of LAS to the clay-silt fraction of river sediments was low, and most of the radioactivity was bound to biomass.
Physiological Characteristics of Cowpea Rhizobia: Evaluation of Symbiotic Efficiency in
Vigna unguiculata
Authors: Zablotowicz R. M. , Focht D. D.
Published: January 2020

One fast-growing and three slow-growing strains of
Rhizobium
(isolated from cowpeas) were evaluated for symbiotic performance on
Vigna unguiculata
(L.) Walp. cultivar California no. 5 blackeyes. Plants inoculated with slow-growing strains 176A22, 176A30, and 176A32 developed a maximum acetylene reduction activity of 24.6, 27.0, and 32 μmol of ethylene formed per plant per h, respectively, versus 6.4 μmol per plant per h in plants inoculated with the fast-growing strain 176A28. When inoculated with approximately equal proportions of rhizobia, the fast-growing strain 176A28 produced 95% of the nodules when challenged with the slow-growing strain 176A22, but formed only 6% of the nodules when challenged with the slow-growing strain 176A30. Consequently, there was no relation between the growth rate in vitro and the capability of rhizobia to compete for nodule-forming sites. Plants inoculated with strain 176A28 and subjected to drought during the vegetative growth period recovered to the same level of nitrogen fixation and nodulation as those that received adequate irrigation. On the other hand, plants inoculated with strains 176A22, 176A30, and 176A32 failed to achieve the same levels of nodulation and nitrogen fixation under drought as compared with irrigated conditions.
Mechanism of enteroviral inactivation by ozone
Authors: Roy D , Wong P K , Engelbrecht R S , Chian E S
Published: January 2020

The mechanism of enteroviral inactivation by ozone was investigated with poliovirus 1 (Mahoney) as the model virus. Ozone was observed to alter two of the four polypeptide chains present in the viral protein coat of poliovirus 1. However, the alteration of the protein coat did not significantly impair virus adsorption or alter the integrity of the virus particle. Damage to the viral RNA after exposure to ozone was demonstrated by velocity sedimentation analysis. It was concluded that the damage to the viral nucleic acid is the major cause of poliovirus 1 inactivation by ozone.
Histopathology of Mycotoxicosis produced in Swiss albino mice by metabolites of some fungal isolates
Authors: Gupta J , Pathak B , Sethi N , Vora V C
Published: January 2020

Of 199 fungal cultures isolated from some of the common cereals collected from different parts of Uttar Pradesh and Madhya Pradesh, 70 produced toxic metabolites. Of the 70 fungi isolated, 59 produced toxins which caused visible lesions in livers, kidneys, and spleens but did not cause mortality. Toxicity, graded in terms of the mortality rate and the extent of lesions in livers, kidneys, and spleens, was found to be highest in various species of Aspergillus (40%), followed by Chaetomium spp. (31%).
Heterotrophic Potentials and Hydrocarbon Biodegradation Potentials of Sediment Microorganisms Within the Athabasca Oil Sands Deposit
Authors: Wyndham R. C. , Costerton J. W.
Published: January 2020

Techniques for the enumeration and the determination of the potential activity of disturbed sediment mixed populations at control sites and sites within the Athabasca oil sands formation were applied to August and December samples. These techniques included the determination of general heterotrophic potential for the assimilation and respiration of glutamate, which indicated no oil sand-related changes in the sediments but which indicated a significant seasonal change. Enumeration by epifluorescence direct counts, oil sand hydrocarbon plate counts, and most-probable-number determinations of [
14
C]hexadecane and [
14
C]-naphthalene degraders indicated that only the plate count was sensitive to increased numbers of oil sand-related hydrocarbon-oxidizing microorganisms within the oil sands deposit. Unlike the most probable number determinations of [
14
C]hexadecane and [
14
C]naphthalene degraders, however, the biodegradation potential results of these substrates indicated a significant increase in activity at oil sands sites. These biodegradation potentials also showed a marked seasonal fluctuation. Although the biodegradation potentials and the endogenous hydrocarbon plate counts indicated an oil sand-adapted mixed sediment population, the results of these techniques did not correlate well with the concentrations of bituminous hydrocarbons in the sediments. The results suggest that a general capability for hydrocarbon oxidation exists in the Athabasca River system and that this capability is enhanced within the natural bounds of the Athabasca oil sands.
In Vitro Microbial Degradation of Bituminous Hydrocarbons and In Situ Colonization of Bitumen Surfaces Within the Athabasca Oil Sands Deposit
Authors: Wyndham R. C. , Costerton J. W.
Published: January 2020

Bituminous hydrocarbons extracted from the Athabasca oil sands of north-eastern Alberta were adsorbed onto filter supports and placed at sites in the Athabasca River and its tributaries where these rivers come in contact with the oil sands formation. Colonization of the hydrocarbon surfaces at summer and winter ambient temperatures was examined by scanning and transmission electron microscopy as well as by epifluorescence microscopy of acridine orange-stained cross sections. Ruthenium red and alkaline bismuth stains visualized an association of bacteria with the hydrocarbon surface which was mediated by bacterial polysaccharides. Bacteria apparently lacking a glycocalyx were also found closely associated with the surface of the hydrophobic substrate and in channels within the substrate. A solvent precipitation and column chromatographic fractionation of the bitumen was followed by cross-tests for growth on the fractions by various isolated sediment microorganisms, as determined by epifluorescence count. All fractions except the asphaltenes supported the growth of at least two of the isolates, although fractionation of degraded bitumen revealed that the saturate, aromatic, and first polar fractions were preferentially degraded.
Technique for Simultaneous Determination of [
35
S]Sulfide and [
14
C]Carbon Dioxide in Anaerobic Aqueous Samples
Authors: Taylor Craig D. , Ljungdahl Per O. , Molongoski John J.
Published: January 2020

A technique for the simultaneous determination of [
35
S]sulfide and [
14
C]carbon dioxide produced in anaerobic aqueous samples dual-labeled with [
35
S]sulfate and a
14
C-organic substrate is described. The method involves the passive distillation of sulfide and carbon dioxide from an acidified water sample and their subsequent separation by selective chemical absorption. The recovery of sulfide was 93% for amounts ranging from 0.35 to 50 μmol; recovery of carbon dioxide was 99% in amounts up to 20 μmol. Within these delineated ranges of total sulfide and carbon dioxide, 1 nmol of [
35
S]sulfide and 7.5 nmol of [
14
C]carbon dioxide were separated and quantified. Correction factors were formulated for low levels of radioisotopic cross-contamination by sulfide, carbon dioxide, and volatile organic acids. The overall standard error of the method was ±4% for sulfide and ±6% for carbon dioxide.
Aberrant Forms of
Streptococcus cremoris
HP
Authors: Keogh Barbara P. , Peterson J. E.
Published: January 2020

The cheese starter strain,
Streptococcus cremoris
HP, produced variant colonies when streaked on the surface of solid media and incubated at 30 or 37°C or in the presence of penicillin. Serial plating and incubation at 37°C or in the presence of penicillin resulted in the production of variants. Subculture followed by incubation at 25°C or in the absence of penicillin resulted in the reversion or partial reversion to the parent form. Colony morphology and cell morphology exhibited the characteristics of the L-phase. Evidence suggested that the aberrant forms of
S. cremoris
at 30°C were transitional phase variants but at 37°C and in the presence of penicillin they were L-phase variants. Electron micrographs showed that the cell walls of the variant cells were defective and that there were differences in the density and the organization of the cytoplasmic constituents compared with the parent cell.
Enterotoxigenic Bacteria in Food and Water from an Ethiopian Community
Authors: Jiwa Sadruddin F. H. , Krovacek Karel , Wadström Torkel
Published: January 2020

Food and water samples from an Ethiopian community were screened for the presence of enterotoxin-producing bacteria. Using the Chinese hamster ovary cell assay, 40 of 213 isolates (18.8%) produced heat-labile (LT) enterotoxin. These LT-producing isolates comprised 33 of 177 (18.6%) strains from 24 of 68 food samples (35.3%) and 7 of 36 (19.4%) isolates of 4 of 17 water samples (23.5%). One LT-producing strain each of
Salmonella emek
and of
Shigella dysenteriae
was found. Three pseudomonads, all LT producers, produced heat-stable enterotoxin as gauged by the suckling mouse test. Two strains of LT-enterotoxigenic
Escherichia coli
O68 were found in water samples. No enterotoxigenic
E. coli
were isolated from food samples, but 13 of the LT-producing strains were
Enterobacter, Klebsiella, Serratia
, and
Proteus
species, and 7 food samples yielded more than one species of enterotoxigenic bacterium. Of the enterotoxigenic isolates from food, 15 were oxidase-positive strains of the genera
Aeromonas, Pseudomonas, Achromobacter, Flavobacterium
, and
Vibrio
. LT-enterotoxigenic
Enterobacter, Acinetobacter, Klebsiella, Proteus, Providencia
, and
Serratia
species represented 20 of the food and water isolates. Culture supernatant fluids of representative strains of oxidase-positive and oxidase-negative species giving positive reactions in Chinese hamster ovary cell tests induced fluid accumulation in rabbit ileal loops. Eight of the food samples and two of the water samples contained more than one isolate or species of enterotoxigenic bacterium. The stability of the LT production by oxidase-positive bacteria and non-
E. coli
strains was assessed by the rabbit skin and adrenal cell tests after 9 months and 1 year of storage, respectively, in Trypticase soy broth with glycerol at −70°C. Only 33% of the oxidase-positive strains were still LT enterotoxigenic. Of the oxidase-negative strains, 50 and 33% were LT producing at 9 months and 1 year, respectively. None of the
E. coli
isolates, both enterotoxigenic and nonenterotoxigenic, possessed K88, K99, or colonization factor antigen. The survey demonstrates the presence in food and water of enterotoxigenic bacteria of the same species as those isolated from cases of infantile diarrhea in the same community, although a correlation between these sources and infantile diarrhea remains to be established.
Immunosuppression by ochratoxin A and its prevention by phenylalanine
Authors: Haubeck H D , Lorkowski G , Kölsch E , Röschenthaler R
Published: January 2020

Ochratoxin A, a toxin of Aspergillus ochraceus, suppresses the immune response to sheep erythrocytes in BALB/c mice at doses as low as 0.005 microgram/kg of body weight. This effect is prevented by phenylalanine.
Comparison of Ethanol Production by Different
Zymomonas
Strains
Authors: Skotnicki M. L. , Lee K. J. , Tribe D. E. , Rogers P. L.
Published: January 2020

A comparison of the rates of growth and ethanol production by 11 different strains of
Zymomonas
revealed a wide range of characteristics, with some strains being more tolerant of high sugar or ethanol concentrations and high incubation temperatures than others. Some strains were unable to utilize sucrose; others produced large amounts of levan, and one strain grew well but produced no levan. One strain, CP4, was considerably better in all respects than most of the other strains and was chosen as a starting strain for genetic improvement of ethanol production.
Distribution of ribonucleic acid coliphages in Korea
Authors: Osawa S , Furuse K , Choi M S , Ando A , Sakurai T , Watanabe I
Published: January 2020

To determine the geographical distribution of ribonucleic acid (RNA) coliphages in Korea, we collected sewage samples from domestic drainage in densely populated urban areas in July through August, 1979. Of 132 samples, 74 (56%) contained RNA phages (106 strains). They were classified into groups I, II and III (4:47:55) by serological analysis. Based on previous data for Japan (groups II and III [3:11]) and Southeast Asia (mostly group III), the distribution pattern of RNA phages in Korea was of an intermediate type between those of Japan and Southeast Asia.
Recovery of parasitic nematodes from fish by digestion or elution
Authors: Jackson G J , Bier J W , Payne W L , McClure F D
Published: January 2020

Two methods, digestion and elution, were used to recover parasitic nematodes from 470 flatfish belonging to species in the family Pleuronectidae. Samples of similar fish were collected from market lots; half of each sample was subjected to digestion, and half was subjected to elution (sedimentation). The edible (flesh) and the inedible (viscera) portions of each fish were analyzed separately. The total number of nematodes recovered by digestion was 1,110, which was not significantly greater than the 922 nematodes recovered by elution. However, digestion recovered 1,062 nematodes of the anisakine genera Anisakis and Phocanema, which are potentially pathogenic for human consumers of raw of semiraw fish. This number is significantly greater than the 608 pathogenic nematodes recovered by elution. Digestion also recovered 242 more nematodes from the edible flesh than did elution. Conversely, more nonpathogenic nematodes were recovered by elution. Approximately half the fish (240) had been collected in Boston markets, and the other half (230) had been collected in San Francisco markets. Fish from San Francisco each contained an average of eight nematodes, and those from Boston contained an average of less than one nematode per fish.
Isolation of
Streptomyces rimosus
Mutants with Reduced Actinophage Susceptibility
Authors: Vešligaj Margareta , Filipović Mirjana , Pigac Jasenka , Hranueli Daslav
Published: January 2020

The infection of
Streptomyces rimosus
by the virulent actinophage RP1 was partially characterized. RP1 infection of the host cells results in a dramatic decrease in viable cell count, followed by reduced antibiotic production. Phage-resistant mutants were isolated after mutagenic treatment and RP1 selective pressure. Characterization of the isolated mutants has revealed that RP1 infection had no influence on their growth and antibiotic production. However, multiplication of the phage particles in the lawns of resistant mutants was detected. Since these strains differ from the wild type in RP1 relative efficiency of plating, plaque morphology, and the time necessary for plaque appearance, they are considered to be semiresistant mutants. The propagation of RP1 on semiresistant strains is characterized by lower adsorption of phage particles and longer latent and rise periods. As a consequence, the multiplication of the phage is slower than that of their host, which consequently reduces the ratio of phage to its host, thus diluting out the phage.
Microplate Technique for Determining Accumulation of Metals by Algae
Authors: Hassett James M. , Jennett J. Charles , Smith James E.
Published: January 2020

A microplate technique was developed to determine the conditions under which pure cultures of algae removed heavy metals from aqueous solutions. Variables investigated included algal species and strain, culture age (11 and 44 days), metal (mercury, lead, cadmium, and zinc), pH, effects of different buffer solutions, and time of exposure. Plastic, U-bottomed microtiter plates were used in conjunction with heavy metal radionuclides to determine concentration factors for metal-alga combinations. The technique developed was rapid, statistically reliable, and economical of materials and cells. Results (expressed as concentration factors) were in reasonably good agreement with literature values. All species of algae studied removed mercury from solution. Green algae proved better at accumulating cadmium than did blue-green algae. No alga studied removed zinc, perhaps because cells were maintained in the dark during the labeling period.
Chlamydomonas
sp. proved superior in ability to remove lead from solution.
Degradation of Phthalic Acids by Denitrifying, Mixed Cultures of Bacteria
Authors: Aftring R. Paul , Chalker Bruce E. , Taylor Barrie F.
Published: January 2020

Mixed cultures of bacteria, enriched from aquatic sediments, grew anaerobically on all three isomers of phthalic acid. Each culture grew anaerobically on only one isomer and also grew aerobically on the same isomer. Pure cultures were isolated from the phthalic acid (
o
-phthalic acid) and isophthalic acid (
m
-phthalic acid) enrichments that grew aerobically on phthalic and isophthalic acids. Cell suspension experiments indicated that protocatechuate is an intermediate of aerobic catabolism. Pure cultures which grew aerobically on terephthalic acid (
p
-phthalic acid) could not be isolated from the enrichments, and neither could pure cultures that grew anaerobically on any of the isomers. Cell suspension experiments suggested that separate pathways exist for the aerobic and anaerobic oxidation of phthalic acids. Each enrichment culture used only one phthalic acid isomer under anaerobic conditions, but all isomers were simultaneously adapted for the anaerobic catabolism of benzoate. Cells grown anaerobically on a phthalic acid immediately attacked the isomer under anaerobic conditions, whereas there was a lag before aerobic breakdown occurred, and, for phthalic and terephthalic acids, chloramphenicol stopped aerobic adaptation but had no effect on anaerobic catabolism. This work suggests that phthalic acids are biodegradable in anaerobic environments.
Reduction of Sulfur Compounds in the Sediments of a Eutrophic Lake Basin
Authors: Smith Richard L. , Klug Michael J.
Published: January 2020

Concentrations of various sulfur compounds (SO
4
2−
, H
2
S, S
0
, acid-volatile sulfide, and total sulfur) were determined in the profundal sediments and overlying water column of a shallow eutrophic lake. Low concentrations of sulfate relative to those of acid-volatile sulfide and total sulfur and a decrease in total sulfur with sediment depth implied that the contribution of dissimilatory sulfur reduction to H
2
S production was relatively minor. Addition of 1.0 mM Na
2
35
SO
4
to upper sediments in laboratory experiments resulted in the production of H
2
35
S with no apparent lag. Kinetic experiments with
35
S demonstrated an apparent

K
m

of 0.068 mmol of SO
4
2−
reduced per liter of sediment per day, whereas tracer experiments with
35
S indicated an average turnover time of the sediment sulfate pool of 1.5 h. Total sulfate reduction in a sediment depth profile to 15 cm was 15.3 mmol of sulfate reduced per m
2
per day, which corresponds to a mineralization of 30% of the particulate organic matter entering the sediment. Reduction of
35
S
0
occurred at a slower rate. These results demonstrated that high rates of sulfate reduction occur in these sediments despite low concentrations of oxidized inorganic compounds and that this reduction can be important in the anaerobic mineralization of organic carbon.
Lizards in the ecology of salmonellosis in Panama
Authors: Kourany M , Telford S R
Published: January 2020

Enteropathogenic bacteria was isolated from 131 of 447 (29.4%) neotropical Panamanian lizards belonging to 34 species of seven families. Overall, 147 strains of bacteria were isolated comprising 26 Salmonella and 10 Arizona serotypes. Gymnopthalmus speciosus had the highest infection rate, 12 of 13 individuals (92.3%), whereas Gonatodes fuscus exhibited the lowest, 1 of 18 (5.6%). The highest infection was detected in lizards whose behavioral patterns were secretive (42.0%) and terrestrial (42.6%), whereas the lowest infection was among the scansorial lizards (17.5%). Rates were highest during the dry season, from January through April. Many neotropical Panamanian lizards were multiply infected by Salmonella an Arizona strains representing representing a wide range of serotypes. Infected lizards were distributed in areas varying from remote rural and forested regions to urban developments, offering a potentially important reservoir of enteropathogenic bacteria known to cause infection in man and domestic animals.
Acidophilic, Heterotrophic Bacteria of Acidic Mine Waters
Authors: Wichlacz Paul L. , Unz Richard F.
Published: January 2020

Obligately acidophilic, heterotrophic bacteria were isolated both from enrichment cultures developed with acidic mine water and from natural mine drainage. The bacteria were grouped by the ability to utilize a number of organic acids as sole carbon sources. None of the strains were capable of chemolithotrophic growth on inorganic reduced iron and sulfur compounds. All bacteria were rod shaped, gram negative, nonencapsulated, motile, capable of growth at pH 2.6 but not at pH 6.0, catalase and oxidase positive, strictly aerobic, and capable of growth on citric acid. The bacteria were cultivatable on solid nutrient media only if agarose was employed as the hardening agent. Bacterial densities in natural mine waters ranged from approximately 20 to 250 cells per ml, depending upon source and culture medium. Ferric hydrates and stream vegetation contained from 1,500 to over 7 × 10
6
cells per g.