bluuebunny/crossref_metadata_2025 huggingface dataset:
Synergic coordination of stem cells is required to induce a regenerative response in anthozoan cnidarians
Authors: Amiel Aldine R. , Foucher Kevin , Ferreira Solène , Röttinger Eric
Published: January 2020

Little is known about the origin of the inductive signal that translates the amputation stress into a cooperative cellular response. By studying the process underlying the reformation of lost body parts in the anthozoan cnidarianNematostella vectensis, we identified a regeneration-inducing structure that, via a tissue crosstalk, is responsible for the initiation of the repair program. We further revealed for the first time in anthozoan cnidarians, that fast and slow-cycling/quiescent stem cells respond to the amputation stress and actively participate in the reformation of lost body parts. Importantly, a synergic interaction of both stem cell populations is required to complete the regeneration process. Our findings suggest that the emergence/loss of structure complexity/compartmentalization influences the proprieties of tissue plasticity, changes the competence of a tissue to reprogram and, in the context of regeneration, the capacity of the tissue to emit or respond to a regeneration-inducing signal.
A Stochastic Model for Actin Waves in Eukaryotic Cells
Authors: Hu Jifeng , Khamviwath Varunyu , Othmer Hans G.
Published: January 2020

A stochastic model of spontaneous actin wave formation in eukaryotic cells that includes positive feedback between the actin network and filament nucleating factors on the membrane is developed and analyzed. Simulation results show that the model can produce a variety of actin network behavior depending on the conditions. Actin spots of diameter about 0.5µmcan be formed and persist for tens of seconds at low actin concentrations, and these spots may either shrink and die or grow and develop into fully-developed propagating waves. The model correctly captures the vertical profile of actin waves along line scans through wave fronts, as well as the separation between the region enclosed by circular actin waves and the external area. Our results show how the complicated actin behavior depends on the amounts and state of various membrane molecules.

Author Summary

Locomotion of eukaryotic cells is a complex process that involves the spatio-temporal control and integration of a number of sub-processes, including the transduction of chemical or mechanical signals from the environment, local and global modification of the cytoskeleton, and translation of the intra- and extracellular signals into a mechanical response. In view of the complexity of the processes, understanding how force generation and mechanical interactions with the surroundings are controlled in space and time to produce cell-level movement is a major challenge. Recent experimental work has shown that a variety of actin waves propagate within cells, both under normal conditions and during re-building of the cytoskeleton following its disruption. Controlled disruption and re-building of the actin network has led to new insights into the key components involved in actin waves, and here we develop a stochastic model that can qualitatively and quantitatively describe the dynamical behavior of such waves.
Responses of New Zealand forest birds to management of introduced mammals
Authors: Fea Nyree , Linklater Wayne , Hartley Stephen
Published: January 2020

Over the past 1000 years New Zealand has lost 40–50% of its bird species, and over half of these extinctions are attributable to predation by introduced mammals. Populations of many extant forest bird species continue to be depredated by mammals, especially rats, possums, and mustelids. The management history of New Zealand's forests over the past 50 years presents a unique opportunity because a varied program of mammalian predator control has created a replicated management experiment. We conducted a meta‐analysis of population‐level responses of forest birds to different levels of mammal control recorded across New Zealand. We collected data from 32 uniquely treated sites and 20 extant bird species representing a total of 247 population responses to 3 intensities of invasive mammal control (zero, low, and high). The treatments varied from eradication of invasive mammals via ground‐based techniques to periodic suppression of mammals via aerially sown toxin. We modeled population‐level responses of birds according to key life history attributes to determine the biological processes that influence species’ responses to management. Large endemic species, such as the Kaka (Nestor meridionalis) and New Zealand Pigeon (Hemiphaga novaeseelandiae), responded positively at the population level to mammal control in 61 of 77 cases for species ≥20 g compared with 31 positive responses from 78 cases for species <20 g. The Fantail (Rhipidura fuliginosa) and Grey Warbler (Gerygone igata), both shallow endemic species, and 4 nonendemic species (Blackbird [Turdus merula], Chaffinch [Fringilla coelebs], Dunnock [Prunella modularis], and Silvereye [Zosterops lateralis]) that arrived in New Zealand in the last 200 years tended to have slight negative or neutral responses to mammal control (59 of 77 cases). Our results suggest that large, deeply endemic forest birds, especially cavity nesters, are most at risk of further decline in the absence of mammal control and, conversely suggest that 6 species apparently tolerate the presence of invasive mammals and may be sensitive to competition from larger endemic birds.
Trichoblastic infundibular cyst should be renamed infundibular cyst with unique papillary projections
Authors: Kobayashi Kenta , Yokoyama Tomoaki , Masuda Yoko , Hashimoto Ichiro , Ansai Shin‐ichi
Published: January 2020

Trichoblastic infundibular cyst (TBIC) was previously reported as a unique keratinous cystic lesion, which was characterized by the papillary projections of follicular germinative‐like cells emanating from the cyst wall. Here, we report three additional cases of this cyst and discuss the pathogenesis of this unique entity. In all cases, a unilocular cyst contained keratin, and the cyst wall was composed of squamous epithelium. A number of cords and papillary projections emanated from the basal layer of the cyst wall. They were composed of cells with large nuclei and scant cytoplasm arranged in a peripheral palisade. Immunohistochemically, anti‐cytokeratin 15, anti‐cytokeratin 20, and anti‐epithelial cell adhesion molecule antibodies were negative. Thus, these cells resembled follicular germinative cells or sebaceous mantle morphologically, but we failed to prove the differentiation immunohistochemically. The cyst was surrounded by fibrotic stroma and inflammatory cells, suggesting previous rupture of the cyst. We speculate that the cells of the projections possibly differentiate into the mantle rather than follicular germinative cells, even though we could not provide sufficient immunohistochemical evidence. We also suggest that they may be induced by special reaction to fibrohistiocytic stroma surrounding the infundibular cyst. Therefore, TBIC should be renamed infundibular cyst with unique papillary projections.
Exploring transitions in care from pulmonary rehabilitation to home for persons with chronic obstructive pulmonary disease: A descriptive qualitative study
Authors: Miranda Jonathan , Underwood Danielle , Kuepfer‐Thomas Miranda , Coulson Drew , Park Andy Chansoo , Butler Stacey J. , Goldstein Roger , Brooks Dina , Everall Amanda C. , Guilcher Sara J. T.
Published: January 2020

Background

Individuals with chronic obstructive pulmonary disease (COPD) often experience high health‐care utilization following pulmonary rehabilitation, suggesting suboptimal transitions to home.

Objective

To understand the experiences of persons with COPD and health‐care professionals regarding transitions from pulmonary rehabilitation to home, including factors impacting these transitions.

Design

A descriptive qualitative study.

Setting and participants

Health‐care professionals working at, and persons with COPD who attended, an inpatient or outpatient pulmonary rehabilitation programme at one large, urban health‐care centre. The centre is located in Ontario, Canada.

Main variable studied

Experiences of participants with care transitions between pulmonary rehabilitation and home. Semi‐structured interviews were audio‐recorded, transcribed verbatim, and thematically analysed.

Results

Ten patients and eight health‐care professionals participated. Four main themes were identified around the overall experiences with pulmonary rehabilitation and transitions to home: (a) pulmonary rehabilitation as a safe environment; (b) pulmonary rehabilitation as a highly structured environment; (c) contrasting perceptions of the role of pulmonary rehabilitation; and (d) dependency on pulmonary rehabilitation programmes. Persons with COPD and health‐care professionals identified three key factors that influenced this transition: (a) patients' social support, (b) application of self‐management strategies prior to discharge, and (c) patients' physical and mental health.

Conclusion

Participants agreed that some patients with COPD experienced suboptimal transitions from pulmonary rehabilitation to home that were characterized by suboptimal self‐management. Further research is needed to develop and evaluate interventions to improve transitions. Such interventions should include strategies to elicit long‐term behaviour change to assist patients when they return into the community.
Photooxidation of cyanobacteria in natural conditions
Authors: Eloff J N , Steinitz Y , Shilo M
Published: January 2020

Photodynamic effects were demonstrated and assayed under field conditions in a number of different laboratory strains and pond isolates of cyanobacteria; parameters assayed for resistance to photooxidation were viable count, turbidity of the cyanobacterial suspension, and protein and pigment contents. The effects of density, colonial structure, and internal gas vacuoles on the lethal outcome were investigated. The stability and formation of superoxide dismutase under photooxidative conditions in the field and laboratory were studied in the different strains. An isolate of Microcystis from blooms in ponds exhibited extremely high resistance to photooxidation, which was abolished by exposure to chloramphenicol.
Aerosol Evaluations of the De Vilbiss No. 40 and Vaponefrin Nebulizers
Authors: Larson Edgar W. , Young Harold W. , Walker Jerry S.
Published: January 2020

De Vilbiss no. 40 and Vaponefrin standard nebulizers produced aerosols of small particles suitable for deep pulmonary vaccination and therapy of respiratory infections in man and animals.
Microbiological oxidation of synthetic chalcocite and covellite by Thiobacillus ferrooxidans
Authors: Sakaguchi H , Torma A E , Silver M
Published: January 2020

The microbiological oxidation of synthetic chalcocite and covellite has been investigated using an adapted strain of Thiobacillus ferrooxidans. Biodegradation of chalcocite was found to be 90 to 100% and that of covellite 45 to 60%. Optimum conditions for the oxidation of chalcocite were: pH, 1.7 to 2.3; temperature, 35 C; and ferric iron concentration in the range of 0.004 to 0.01 M. For covellite, the optimum conditions were: pH 2.3; temperature, 35 C; and ferric iron concentration in the range of 0.004 to 0.02 M. The energies of activation were determined to be 16.3 kcal (ca. 6.8 X 10(4) J) per mol and 11.7 kcal (ca. 4.8 X 10(4) J) per mol for chalcocite and covellite, respectively.
Chilling cells enhances the bactericidal action of fatty acids on Escherichia coli
Authors: Fay J P , Farías R N
Published: January 2020

Preincubation at 0 C considerably increased the bactericidal action of 0.4% nonanoic and decanoic acids on Escherichia coli K-12 154. This lethal effect seemed to be dependent on the media used to grow the bacteria. Stationary-phase cells were more sensitive than those from exponential cultures. A mutant (FA31) resistant to the bactericidal action of "cold shock" and 0.4% deconoic acid was isolated from E. coli FA23 (AN E. coli 154 derivative able to grow on 0.1% decanoic acid) by a recycling selection procedure. Other E. coli strains tested showed behavior similar to that of strain K-12 154. The chilling of cells as a tool to improve the bactericidal action of fatty acids in foods is discussed.
Initial fast reaction of bromine on reovirus in turbulent flowing water
Authors: Sharp D G , Floyd R , Johnson J D
Published: January 2020

An apparatus is described for precise observation of the kinetics of the initial fast reaction of bromine with reovirus in turbulent flowing water. When quantitative electron microscopy shows that virus suspensions are essentially all single particles, the loss of infectivity follows first-order kinetics, the plaque titer falling at the rate of 3 log10 units/s at pH 7, 2 C, and at a 3-muM bromine concentration. Virus suspensions containing small aggregates (2 to 10/clump) exhibit a constantly decreasing disinfection rate with bromine. At a survival level of 10(-3) for single virions, the aggregated preparations have lost only 99% of their plaque titer and 10(-4) is reached only after 4 s of exposure. The disinfection rate does not appear to be a simple function of the size and frequency of aggregates in the virus suspension even when the aggregates contain no foreign material. Unpurified virus preparations (crude freeze-thaw lysates of infected cells) are shown, by zonal centrifugation, to contain 50% to over 90% of the infectivity in large, fast sedimenting aggregates. Such aggregates would strongly influence the bromine resistance of virus in polluted water.
Heterotrophic utilization of glucose and glutamate in an estuary: effect of season and nutrient load
Authors: Carney J F , Colwell R R
Published: January 2020

Uptake of 14C-labeled glucose and glutamate was studied at several sites in Baltimore Harbor, Eastern Bay, and the Rhode River. Levels of uptake of 14C-labeled glutamate, measured over a period of 1 year during September, December, April, May, and June to estimate seasonal effects on heterotrophic utilization of selected nutrients, were highest in May and lowest in December. In a comparison of visibly polluted and unpolluted sites, the greatest amount of incorporation of glucose or glutamate and the highest Vmax values were observed at those sites where the microorganisms were exposed to varied and higher levels of pollutants, suggesting that Vmax may function as an indicator of relative pollution. Mineralization values ranged from 30 to 43%. A range of 0.44 to 2.32 mumol of C/liter per day was calculated for glutamate uptake.
Synthesis of staphylococcal enterotoxin A and nuclease under controlled fermentor conditions
Authors: Carpenter D F , Silverman G J
Published: January 2020

The production of enterotoxin A and nuclease by Staphylococcus aureus strain 100 was studied in a 1.0-liter fermentor. The effects of the gas flow rate, pH, and dissolved oxygen were evaluated. Toxin and nuclease secretion occurred under all conditions which permitted growth of the organism. Final yields of toxin and nuclease in cultures grown at constant air flow rates, ranging from 50 to 500 cm3 per min, were higher at successively higher flow rates. An optimum flow rate for either toxin or nuclease production was not observed. When the aeration rate alone or aeration rate and pH were held constant, the dissolved oxygen levels in the culture decreased from the initial 100% level to 0 to 5% 3 to 4 h after inoculation. The O2 demand of the culture then maintained this level for an additional 4 to 5 h. This low dissolved oxygen interval was characterized by rapid growth and extracellular protein production. Controlling the dissolved oxygen at a constant level throughout growth did not increase the final levels of toxin and nuclease above those achieved at the respective constant pH values. Growth under the influence of a constant aeration rate of 500 cm3 per min and a constant pH of 6.5 and 7.0 yielded the highest titers of nuclease (1,550 units/ml) and toxin (10.5 mug/ml) obtained in any of the fermentations conducted in this study. Sparging fermentor cultures with pure oxygen at a rate of 100 cm3 per min yielded growth and extracellular protein levels similar to those achieved at the sparge rate of 500 cm3 of air per min. Controlling the dissolved oxygen at 100% of pure oxygen saturation appeared to inhibit the culture, as the final cultural turbidity as well as the levels of toxin and nuclease were reduced. These data indicate that enterotoxin and nuclease secretions are closely associated with the growth of strain 100. Analyses of the production rates of these components indicated that early log phase was the most efficient production interval in the growth cycle and that this efficiency was increased by pH control at 6.7 to 6.8 and dissolved oxygen control at 10% of air saturation.
Kinetics of Growth and Substrate Uptake in a Biological Film System
Authors: La Motta Enrique J.
Published: January 2020

The rates of growth and substrate uptake in a biological film continuous-flow reactor were studied. The experiments were performed with high fluid velocities to bring the reactor operation to the reaction-controlled regime, thus avoiding external diffusional resistances. The glucose uptake experiments were performed with small film thicknesses so that full substrate penetration within the entire film thickness could be obtained. In this way, the catalyst effectiveness factor was 1.0 and the observed rate was the true, or intrinsic, rate. The results of the experiments indicate that both the intrinsic rate of substrate uptake and the rate of film growth are independent of the substrate concentration remaining in the reactor (zero-order reactions). However, the value of the initial substrate concentration when the film is in the early stages of growth defines the magnitude of both the rate of uptake and growth. This effect of the initial substrate concentration follows a saturation-function pattern.
Comparison of Surface Pore Morphology of Two Brands of Membrane Filters
Authors: Standridge Jon H.
Published: January 2020

The surface pore morphology of two brands of membrane filters was studied by using scanning electron microscopy. The differences observed are presented as a possible explanation for reported discrepancies in coliform recovery from water.
Bedding disposal cabinet for containment of aerosols generated by animal cage cleaning procedures
Authors: Baldwin C L , Sabel F L , Henke C B
Published: January 2020

Laboratory tests with aerosolized spores and animal room tests with uranine dye indicate the effectiveness of a prototype bedding disposal cabinet in reducing airborne contamination generated by cage cleaning procedures.
Microbiological quality of frozen breaded fish and shellfish products
Authors: Baer E F , Duran A P , Leininger H V , Read R B , Schwab A H , Swartzentruber A
Published: January 2020

A survey was made of the microbiological quality of seven frozen, breaded, precooked fish and shellfish products and of frozen, breaded, uncooked shrimp at the retail level. Geometric mean aerobic plate counts per gram (and number of units examined) were as follows: fish sticks, 8,300 (1,539); fish cakes, 5,600 (1,378); crab cakes, 4,900 (1,226); scallops, 1,700 (1,392); clams, 450 (1,384); haddock, 15,000 (1,306); fish in fish and chips dinner, 7,200 (1,485); and uncooked shrimp, 220,000 (1,462). Geometric mean coliform, Escherichia coli, and Staphylococcus aureus counts for all eight products ranged from 1 to 10/g.
Inhibitory effects of H2 on growth of Clostridium cellobioparum
Authors: Chung K T
Published: January 2020

Hydrogen inhibits the growth of hydrogen-producing Clostridium cellobioparum, but not of Escherichia coli or Bacteroides ruminicola. The inhibition is reversible. When hydrogen was removed either by palladium black or by gassing out the tube, glucose utilization increased as did optical density and hydrogen production of C. cellobioparum. Removal of the H2 by methanogenic bacteria favors the growth of C. cellobioparum. Grown with Methanobacterium ruminantium in various concentrations of glucose, the Clostridium reaches a higher optical density and produces more H2 and a higher viable cell count. The cell yield is also higher than in pure culture. In mixed culture, C. cellobioparum produces more acetic acid and less lactic acid, ethanol, and butyric acid than in pure culture. The significance of this metabolic shift and hydrogen utilization in methanogenesis is discussed.
Production of ochratoxin A by Aspergillus ochraceus NRRL-3174 before and after exposures to 60Co irradiation
Authors: Applegate K L , Chipley J R
Published: January 2020

Spores from the toxigenic organism Aspergillus ochraceus NRRL-3174 were exposed to specific levels of gamma irradiation and then allowed to germinate on selected media. Increases in ochratoxin A production by irradiated, compared to non-irradiated, spores were observed after inoculation of spores onto a cracked red wheat or into a synthetic liquid medium. Variations in daily ochratoxin production were also observed for control and irradiated spore-derived cultures developing on both media, with maximum toxin production varying from 7 to 11 days of incubation. The most notable increases in ochratoxin A production occurred from cultures developing from spores having been irradiated with 10, 25, or 50 krad. Exposures to 400 or 600 krad resulted in complete inhibition of spore germination and, consequently, no ochratoxin production. Of the two substrates used, wheat and synthetic, the quantities of ochratoxin A produced were significantly lower in the synthetic media than on the natural substrate. Higher and more rapid toxin production occurred from spores having been irradiated with 10, 25, 50, and 100 krad than occurred from the non-irradiated control spores when grown on synthetic media. Cultures derived from spores having been exposed to 10, 25, 50, and 100 krad produced significantly higher levels of ochratoxin A after 8 days of incubation on natural substrate than did the controls. Analysis of variance revealed that substrate, length of incubation, as well as irradiation levels all affected the time required to produce maximum levels of ochratoxin A.
Growth Requirements of San Francisco Sour Dough Yeasts and Bakers' Yeast
Authors: Henry NG
Published: January 2020

The growth requirements of several yeasts isolated from San Francisco sour dough mother sponges were compared with those of bakers' yeast. The sour dough yeasts studied were one strain of
Saccharomyces uvarum
, one strain of
S. inusitatus
, and four strains of
S. exiguus. S. inusitatus
was the only yeast found to have an amino acid requirement, namely, methionine. All of the yeasts had an absolute requirement for pantothenic acid and a partial requirement for biotin. Inositol was stimulatory to all except bakers' yeast. All strains of
S. exiguus
required niacin and thiamine. Interestingly,
S. inusitatus
, the only yeast that required methionine, also needed folic acid. For optimal growth of
S. exiguus
in a molasses medium, supplementation with thiamine was required.
Morphology and ultrastructure of a Penicillium sp. grown on n-hexadecane or peptone
Authors: Cundell A M , Mueller W C , Traxler R W
Published: January 2020

The morphology and ultrastructure of a Penicillium sp. grown on n-hexadecane or on peptone in shake-culture were compared using transmission and scanning electron microscopy. The fungus grew as hollow mycelial balls surrounding individual hydrocarbon droplets on n-hexadecane and as solid mycelial balls on peptone. A dense layer of fungal mycelium that showed irregular forms, fusion, and increase in hyphal size formed at the hydrocarbon-water interface. Inclusions were present in the hexadecane-grown fungus that were absent when the Penicillium sp. was grown on peptone. Problems of fixation made it difficult to differentiate detailed changes in the cytoplasm when the fungus was examined with the transmission electron microscope.
Physiology and ecology of bacteriophages of the marine bacterium Beneckea natriegens: salinity
Authors: Zachary A
Published: January 2020

The effects of variation in ionic levels on the stability and replication of two bacteriophages (nt-1 and nt-6) host specific for the marine bacterium Beneckea natriegens were examined. Monovalent cations influenced the adsorption of the nt-1 but not the nt-6 phage; however, one-step growth studies showed that NaCl was required for replication of both phage. The NaCl optimum for nt-1 production was 0.25 M NaCl, the same as the growth optimum for B. natriegens. However, the optimum for nt-6 production was 0.16 M NaCl. These NaCl optima for host and phage are at estuarine rather than oceanic levels. The nt-1 phage was better suited to replicate at NaCl levels typical of higher salinity areas (18-35%) and the nt-6 phage was better suited to replicate at lower salinities (5-18%). The nt phage were more resistant to low NaCl levels than their host bacterium and appeared limited to marine waters by the lower survival salinity of B. natriegens coupled with phage inactivation processes occurring in natural estuarine waters.
Influence of starch source on sporulation and enterotoxin production by Clostridium perfringens type A
Authors: Labbe R , Somers E , Duncan C
Published: January 2020

Of 16 different starch preparations tested, Clostridium perfringes NCTC 8798 yielded maximum sporulation and enterotoxin formation when ICN-soluble starch was included in Duncan and Strong sporulation medium. In general soluble starches were better than potato, corn, or arrowroot starch with regard to these two parameters.
Citric acid metabolism in hetero- and homofermentative lactic acid bacteria
Authors: Drinan D F , Robin S , Cogan T M
Published: January 2020

The effect of citrate on production of diacetyl and acetoin by four strains each of heterofermentative and homofermentative lactic acid bacteria capable of utilizing citrate was studied. Acetoin was quantitatively the more important compound. The heterofermentative bacteria produced no acetoin or diacetyl in the absence of citrate, and two strains produced traces of acetoin in its presence. Citrate stimulated the growth rate of the heterofermentative lactobacilli. Acidification of all heterofermentative cultures with citric acid resulted in acetoin production. Destruction of accumulated acetoin appeared to coincide with the disappearance of citrate. All homofermentative bacteria produced more acetoin and diacetyl in the presence of citrate than in its absence. Citrate utilization was begun immediately by the streptococci but was delayed until at least the middle of the exponential phase in the case of the lactobacilli.
Chemical manipulation of the heat resistance of Clostridium botulinum spores
Authors: Alderton G , Ito K A , Chen J K
Published: January 2020

The chemical forms of Clostridium botulinum 62A and 213B were prepared, and their heat resistances were determined in several heating media, including some low-acid foods. The heat resistance of C. botulinum spores can be manipulated up and down by changing chemical forms between the resistant calcium form and the sensitive hydrogen form. The resistant chemical form of type B spores has about three times the classical PO4 resistance at 235 F (112.8 C). As measured in peas and asparagus, both types of C. botulinum spores came directly from the culture at only a small fraction of the potential heat resistance shown by the same spores when chemically converted to the resistant form. The resistant spore form of both types (62A and 213B), when present in a low-acid food, can be sensitized to heating at the normal pH of the food.
Evaluation of an automated fluorescent antibody procedure for detection of Salmonella in foods and feeds
Authors: Munson T E , Schrade J P , Bisciello N B , Fantasia L D , Hartung W H , O'Connor J J
Published: January 2020

A prototype automated system using fluorescent antibody (FA) was evaluated for rapid detection of salmonellae in foods. Samples were enriched in selenite cystine and tetrathionate broths. After incubation, both were transferred into fresh selenite cystine for a 4-h "post-enrichment" to dilute possible background fluorescence from product. These cultures were then analyzed automatically, and results were compared with those obtained by the methods of the Association of Official Analytical Chemists (AOAC). Initially, 167 samples of milk powder, dried yeast, and imported frog legs were examined. The AOAC and automated FA methods correlated well with all samples but frog legs. Difficulty with the latter was caused by procedural and mechanical problems coupled with high numbers of competing microorganisms in post-enrichment cultures. Modification of procedure and partial redesign of equipment corrected these difficulties, and excellent correlation was obtained with another 116 frog leg samples. All 89 AOAC-confirmed positives were also detected by the automated FA method, and there were only 4% false FA positives. The system shows potential for screening products for salmonellae; however, all positives should be confirmed by manual biochemical and serological methods.
Oil degradation in soil
Authors: Raymond R L , Hudson J O , Jamison V W
Published: January 2020

The environmental effects of adding certain selected petroleum products to field soils at widely separated geographical locations under optimum conditions for biodegradation were studied. The locations selected for study of soil biodegradation of six oils (used crankcase oil from cars, used crankcase oil from trucks, an Arabian Heavy crude oil, a Coastal Mix crude oil, a home heating oil no. 2, and a residual fuel oil no. 6) were Marcus Hook, Pennsylvania, Tulsa, Oklahoma, and Corpus Christi, Texas. The investigative process, covering a period of 1 year at each location, was conducted in 14 fields plots (1.7 by 3.0 m) to which the oils were added in a single application at a rate of 11.9 m3/4 X 10(3) m2. One-half of the plots at each location were fertilized, and the incorporation of the oils and fertilizers was accomplished with rototillers to a depth of 10 to 15 cm. Concentrations of all oils decreased significantly at all locations. The average reduction ranged from 48.5 to 90.0% depending upon the type of oil and location. Rates of degradation did not exceed 2.4 m3/4 X 10(3) m2 per month. Compositional changes in the oil with time were investigated using silica gel fractionation, gas chromatography, and ultraviolet absorbance. With the possible exception of the two fuel oils, the compositional changes were generally in the same direction for all of the oils. The silica gel fractionation and gravimetric data on residual oils show that all classes of compounds were degraded, but the more polar type degrade more slowly. Analysis of runoff water, leachate, and soils indicated that at the concentration applied no oil less was observed from these plots via water movement. No significant movement of lead compounds added to the soils in the used crankcase oils was observed. Significant increases in hydrocarbon-utilizing microorganisms were demonstrated in all treated plots using either the pure hydrocarbon, n-hexadecane, or the applied oils as the growth substrate. These increases were usually sustained throughout the year. Significant increases in hydrocarbon-utilizing fungi were not demonstrated by the plating technique used. The concentrations of residual oils or their oxidation products were of sufficient magnitude in the treated plots, 9 months after application, to cause significant inhibition of plant growth. From the data obtained, it was not possible to determine the type of compounds causing this inhibition or their long-term environmental effects.
Effect of iron on the biodegradation of petroleum in seawater
Authors: Dibble J T , Bartha R
Published: January 2020

The biodegradation of South Louisiana (SL) crude oil and the effects of nitrogen, phosphorus, and iron supplements on this process were compared in a polluted (10,900 oil degraders per liter) and in a relatively clean (750 oil degraders per liter) littoral seawater sample taken along the New Jersey coast. Without supplements, the biodegradation of SL crude oil was negligible in both seawater samples. Addition of nitrogen and phosphorus allowed very rapid biodegradation (72% in 3 days) in polluted seawater. Total iron in this seawater sample was high (5.2 muM), and the addition of iron did not increase the biodegradation rate further. In the less polluted and less iron-rich (1.2 muM) seawater sample, biodegradation of SL crude oil was considerably slower (21% in 3 days) and the addition of chelated iron had a stimulating effect. Ferric octoate was shown to have a similar stimulating effect on SL crude oil biodegradation as chelated iron. Ferric octoate, in combination with paraffinized urea and octylphosphate, is suitable for treatment of floating oil slicks. We conclude that spills of SL crude and similar oils can be cleaned up rapidly and efficiently by stimulated biodegradation, provided the water temperatures are favorable.
Surface balance study of the interaction between microorganisms and lipid monolayer at the air/water interface
Authors: Kjelleberg S , Norkrans B , Löfgren H , Larsson K
Published: January 2020

Using the surface balance technique, we have compared the interaction between Acholeplasma laidlawii and some marine bacteria towards different types of monolayered lipid films. Cells from A. laidlawii and Serratia marinorubra penetrate the film, whereas cells from Psuedomonas fluorescens form a layer underneath the film. The forces that bind microorganisms to the air/water interface are not strong enough to scatter a condensed monolayer but increase the strength of loosely packed monolayers.
Isolation of salmonellae and other potential pathogens from the freshwater aquarium snail Ampullaria
Authors: Bartlett K H , Trust T J
Published: January 2020

The freshwater aquarium snail (Ampullaria spp.) was demonstrated to carry as many as 10(8) viable mesophilic bacteria per g of meat plus shell. Some 16 genera of bacteria were identified, with gram negatives predominating. Enrichment culture techniques enabled the isolation of salmonellae from 24 to 42 lots of 200 g each. The salmonellae comprised eight different serotypes, including Salmonella newport, Salmonella saint-paul, and Salmonella infantis. This association of salmonellae with snails may contribute to cases of human salmonellosis, since other aquarium species have already been shown to contribute to many such cases. The snails were also found to commonly harbor Pseudomonas aeruginosa and, occasionally, Edwardsiella tarda.
Beta-glucosidase of Trichoderma: its biosynthesis and role in saccharification of cellulose
Authors: Sternberg D
Published: January 2020

The extracellular beta-glucosidase of Trichoderma viride generally is present in low levels when the organism is cultured on cellulose because it is inactivated under the acid conditions which develop in the medium while the other enzymes of the cellulase complex are more stable. With the appropriate pH control, inactivation of beta-glucosidase is prevented and the activity of this enzyme increases during growth. In the saccharification of crystalline cellulose, or of cellulose at low concentrations, much of the glucose produced is the result of the cleavage of cellobiose by beta-glucosidase. However when high concentrations (10%) of pretreated cellulose are saccharified, significant quantities of glucose are produced by action of enzymes other than beta-glucosidase.
Comparison between numbers and kinds of freshwater protozoans colonizing autoclaved and unautoclaved polyurethane foam substrates
Authors: Yongue W H , Cairns J
Published: January 2020

Autoclaved and unautoclaved polyurethane substrates were placed in Douglas Lake, Michigan, to determine whether fatty amines produced by autoclaving affected the colonization process. These results indicate that there was no major difference in the numbers of colonizing species in either kind of substrate. The kinds of species showed considerable overlap among the categories of substrate.
Changes in Resident Bacteria, pH, Sucrose, and Invert Sugar Levels in Sugarbeet Roots During Storage
Authors: Cole D. F. , Bugbee W. M.
Published: January 2020

Stored sugarbeet roots began fermenting within 24 h after oxygen was depleted at 26 C when the resident bacterial populations increased dramatically. Most of the bacteria present after anaerobic storage for 7 days at 26 C could hydrolyze sucrose in vitro. Although pH and sucrose levels decreased and invert sugar levels increased with time in aerobic storage at 26 C, these processes were significantly accelerated in beets stored anaerobically at 26 C. Under oxygen-depleted storage conditions at 26 C, the sucrose content was almost completely lost after 21 days.
Role of bacteria and protozoa in the removal of Escherichia coli from estuarine waters
Authors: Enzinger R M , Cooper R C
Published: January 2020

The removal of Escherichia coli from estuarine water was investigated. The survival of E. coli was dependent on the presence of protozoan predators and not on the presence of lytic bacteria. When indigenous protozoa were removed from estuarine water by filtration, the destruction of coliform populations was negligible. In studies designed to prevent the growth of indigenous bacterial populations without affecting protozoan populations, coliform destruction was significant.
Effect of a sputum digestant on the viabiltiy of Mycobacterium fortuitum
Authors: Baker D C , Hsu E J
Published: January 2020

A microcolony technique has been demonstrated as being useful for the rapid determination of the viabilities of single cells of Myocbacterium fortuitum. Cultures of M. fortuitum grown to early logarithmic phase in broth were treated with the sputum digestant N-acetyl-L-cysteine-sodium hydroxide (NALC-NaOH) for periods of 10 to 40 s. After growth for three generations (7.5 h) on agar films, viabilities were determined by counting under a phase contrast microscope. The viable mycobacteria grew into microcolonies that exhibited extensive branching, whereas the nonviable mycobacteria remained as single cells. Sputum was mixed with some broth cultures before treatment to stimulate the digestion process in a clinical laboratory. When broth cultures were treated with sputum digestant for 40 s, only 2.8% of the cells remained viable. When the broth cultures were mixed in a ratio of 1:4 with sputum and then treated for 40 s, 16.4% of the cells remained viable. The results also indicate M. fortuitum is very sensitive to the digestant. The results also indicate that a microcolony technique could be used for the assessment of the viability of mycobacteria.
Protein Synthesis at 680 atm: Is It Related to Environmental Origin, Physiological Type, or Taxonomic Group?
Authors: Pope Daniel H. , Smith Walter P. , Orgrinc Michael A. , Landau Joseph V.
Published: January 2020

The ability of bacteria to synthesize protein at 680-atm pressure is not related to their environmental origin, physiological type, or taxonomic group.
Degradation of [8,9,-14C]endosulfan by soil microorganisms
Authors: Martens R
Published: January 2020

Twenty-eight soil fungi, 49 soil bacteria, and 10 actinomycetes were tested as to their ability to degrade the insecticide endosulfan. Using 14C-labeled material, the qualitative as well as the quantitative formation of metabolities, as well as of 14CO2, could be followed. Sixteen fungi, 15 bacteria, and 3 actinomycetes were found capable of metabolizing more than 30% of the applied endosulfan. The major metabolities detected were endosulfate, formed by oxidation of the sulfite group, and endodiol, formed by hydrolysis of the ester bond. The majority of highly active fungi formed endosulfate as the major metabolite, whereas the majority of active bacteria formed endodiol. In addition to endosulfate and endodiol, individual cultures contained small quantities of endohydroxyether and two unidentified products. The very small quantities of 14CO2 evolved from cultures indicated that an extensive mineralization of the carbon skeleton of endosulfan did not occur.
Stabilization of a psychrotrophic Pseudomonas protease by calcium against thermal inactivation in milk at ultrahigh temperature
Authors: Barach J T , Adams D M , Speck M L
Published: January 2020

The heat-stable extracellular protease of Pseudomonas sp. (isolate MC60) was investigated. Heat resistance of the enzyme in milk at sterilization temperature was dependent on the presence of Ca2+. The half-life of the enzyme at ultrahigh temperature (149 C) in skim milk or milk-salts buffer with Ca2+ was approximately 7.0 s. Treatment of milk with chelators completely removed the heatstabilizing effect of milk. The enzyme was partially purified by ammonium sulfate precipitation and column chromatography on Sephadex G-100. At 21 C the enzyme retained greater than 85% activity after exposure to pH values between 5 and 10. Enzyme activity was reduced by metal chelating agents. Both Ca2+ and Zn2+ were required for optimal enzyme activity. Molecular weight was estimated at 48,000 by gel filtration.
Viscometric assay of bacterial alginase
Authors: Stevens R A , Levin R E
Published: January 2020

Equations defining the reaction of microbial alginase on commercial sodium alginate are presented with respect to the viscometric assay of enzyme activity. The negative log of K was found to be linearly related to the concentration of algin, where K is defined as the change in the reciprocal of relative viscosity with time. The negative log of K was also found to be linearly related to the amount of enzyme in reaction mixtures when the substrate concentration was held constant.
Survival of bacteria in seawater using a diffusion chamber apparatus in situ
Authors: Vasconcelos G J , Swartz R G
Published: January 2020

A microbiological survival chamber for in situ environmental studies involving microorganisms of public health significance was developed. The autoclavable chamber was provided with a supportive base for proper flow orientation and a battery-powered stirring mechanism for continuous internal agitation. The performance of the chamber and its ancillary units was evaluated in estuarine waters by diffusion studies and survival tests with eight species of bacteria isolated from environmental sources. Polycarbonate filter membranes were found superior to cellulosic filter membranes. Continuous mixing enhanced diffusion and ensured uniform cell suspension. Salmonella enteritidis and Klebsiella pneumoniae exhibited somewhat greater viability than Escherichia coli under similar conditions. Of three indicator organisms tested, Streptococcus faecalis was the most persistent. In general, the data obtained indicate the usefulness of the chamber in measurements of microbial survival in the natural marine environment.
Carbon metabolism in model microbial systems from a temperate salt marsh
Authors: Fallon R D , Pfaender F K
Published: January 2020

The metabolism of a saltwater leachate of 14C-labeled Spartina alterniflora was examined in laboratory systems using mixed, salt marsh microbial communities and, by addition of appropriate antibiotics, communities with bacteria or eukaryotes inhibited. Label uptake was more rapid in the systems with bacteria alone and with the mixed microbial community than with fungi alone. Mineralization of the added label was more extensive in the mixed and bacterial systems, whereas the fungi appear more efficient at converting the label into particulate biomass. Particulate biomass production efficiencies ranged from a high of 0.82 for the fungal system to 0.21 in the mixed community, with the bacterial system giving an intermediate value of 0.54. The presence of protozoa and microcrustaceans in the mixed system appears to account for an increase in the mineralization of the label assimilated. Additional experiments with whole labeled Spartina, a leachate from Spartina, and Spartina after leaching revealed that the seawater-soluble portions of the plants were attacked most rapidly by the microbial community.
Electron transport components of the MnO2 reductase system and the location of the terminal reductase in a marine Bacillus
Authors: Ghiorse W C , Ehrlich H L
Published: January 2020

The response of MnO2 reduction by uninduced and induced whole cells and cell extracts of Bacillus 29 to several electron transport inhibitors was compared. MnO2 reduction with glucose by uninduced whole cells and cell extracts was strongly inhibited at 0.1 mM dicumarol, 100 mM azide, and 8 mM cyanide but not by atebrine or carbon monoxide, suggesting the involvement of a vitamin K--type quinone and a metalloenzyme in the electron transport chain. MnO2 reduction with ferrocyanide by uninduced cell extracts was inhibited by 5 mM cyanide and 100 mM azide but not by atebrine, dicumarol, or carbon monoxide, suggesting that the metalloenzyme was associated with the terminal oxidase activity. MnO2 reduction with glucose by induced whole cells and cell extracts, was inhibited by 1 mM atebrine, 0.1 mM dicumarol, and 10 mM cyanide but not by antimycin A, 2n-nonyl-4-hydroxyguinoline-N-oxide) (NOQNO), 4,4,4-trifluoro-1-(2-thienyl),1,3-butanedione, or carbon monoxide. Induced cell extract was also inhibited by 100 mM azide, but stimulated by 1 mM and 10 mM azide. Induced whole cells were stimulated by 10 mM and 100 mM azide. These results suggested that electron transport from glucose to MnO2 in induced cells involved such components as flavoprotein, a vitamin K-type quinone, and metalloenzyme. The stimulatory effect of azide on induced cells was explained on the basis of a branching in the terminal part of the electron transport chain, one branch involving a metalloenzyme for the reduction of MnO2 and the other involving a metalloenzyme for the reduction of oxygen. The latter was assumed to be the more azide sensitive. Spectral studies showed the presence of a-, b-, and c-type cytochromes in membrane but not in soluble fractions. Of these cytochromes, only the c type may be involved in electron transport of MnO2, owing to the lack of inhibition by antimycin A or 2n-nonyl-4-hydroxyquinoline-N-oxide. The terminal MnO2 reductase appears to be loosely attached to the cell membrane of Bacillus 29 because of cell fractionation it is found associated with both particulate and soluble fractions. Electron photomicrographs of bacilli attached to synthetic Fe-Mn oxide revealed an intimate contact of the cell walls with the oxide particles.
Observations on lysogeny in glutamic acid bacteria
Authors: Shapiro J A
Published: January 2020

Induced lysis occurred in a number of different strains of glutamic acid bacteria. Mixed culture experiments indicated that induced cultures produce phages or bacteriocins. Temperate phages were isolated from two related strains of Brevibacterium divaricatum.
Method of Purifying β-(1-3)-Glucanase from
Candida utilis
Authors: Villa T. G. , Notario V. , Villanueva J. R.
Published: January 2020

A method has been developed to obtain a rapid purification of the β-(1-3)-glucanase present in culture fluids of the yeast
Candida utilis.
Staphylococci from the feces of different animal species: biotypes of Staphylococcus aureus strains of sheep and goat origin
Authors: Dimitracopoulos G , Sakellariou C , Papavassiliou J
Published: January 2020

Staphylococcus aureus was found in 96% of the rectal swabs from 133 sheep and in 80% of the swabs from 125 goats. Seventy-seven percent of the isolates from both hosts exhibited the fibrinolytic and growth characteristics of human biotype A on human plasma and crystal violet agar, respectively, but 99% of these isolates resembled S. aureus of animal origin in their other properties. Only 21% of the sheep and 24% of the goat isolates were clearly identifiable as human biotype A and animal biotypes B and C.