scholarly journals Assessment of the flocculating potentials of Alcaligenes faecalis Isolated from the Estuary of Sodwana Bay

2018 ◽  
Vol 3 (2) ◽  
pp. 1-7
Author(s):  
Anthony M. Ugbenyen ◽  
Thandakile A. Madonsela ◽  
John J. Simonis ◽  
Albertus K. Basson
Keyword(s):  
Time Course ◽  
Culture Media ◽  
Alcaligenes Faecalis ◽  
Inoculum Size ◽  
Production Potential ◽  
Inoculum Sources ◽  
Carbon And Nitrogen ◽  
Flocculating Activity ◽  
Optimum Ph ◽  
Time Courses

AbstractAlcaligenes faecaliswas previously isolated from Sodwana Bay, South Africa and was shown to be a bioflocculant producing microorganism. The bioflocculant production potential was further assessed through the optimization of the standardized culture media. The production of biofloculant as well as the flocculation was evaluated using different variables such as the size of inoculum, sources of carbon and nitrogen, time course and pH. Through optimizationA. faecalisshowed an improvement in the production of its bioflocculant and also flocculating activity for the following factors: flocculating activity of 71% for an inoculum size of 1%. The bioflocculant produced when maltose was used as source of carbon, showed flocculating activity of 91%, urea, as the most efficient nitrogen source, showed a flocculating activity of 97%, the optimum pH was 9. The time courses analysis between 60 and 72 hours showed the peak for flocculation and by implication highest level of bioflocculant production.

Production of a Bioflocculant by Penicillium Sp. HHE-P7 Using Sugarcane Molasses

2012 ◽  
Vol 518-523 ◽  
pp. 453-459
Author(s):  
Li Fan Liu
Keyword(s):  
Rotation Speed ◽  
Fermentation Broth ◽  
Nitrogen Sources ◽  
Culture Conditions ◽  
Inoculum Size ◽  
Carbon And Nitrogen Sources ◽  
Carbon And Nitrogen ◽  
Medium Components ◽  
Flocculating Activity ◽  
Initial Ph

Bioflocculant MBF7 was produced by a novel bioflocculant-producing microorganism HHE-P7. In order to reduce the bioflocculant producing cost, culture experiments were conducted. The effects of medium components including carbon and nitrogen sources as well as culture conditions such as pH of molasses diluents, cultivating temperature, inoculum size were investigated. The results showed when the molasses waste was diluted at COD concentration of 2000 mg/L, the optimal culture conditions for MBF7 production by HHE-P7 were inoculum size 1% (v/v), initial pH 5, cultivating temperature 25°C at the rotation speed 150 r/min. Under such conditions, MBF7 had a flocculating activity of 83% for 5 g/L kaolin clay suspension. About 3.19 g crude bioflocculant could be recovered from 1.0 L of molasses fermentation broth.

scholarly journals Pseudo-streaming potentials in Necturus gallbladder epithelium. II. The mechanism is a junctional diffusion potential.

1992 ◽  
Vol 99 (3) ◽  
pp. 317-338 ◽  
Author(s):  
L Reuss ◽  
B Simon ◽  
C U Cotton
Keyword(s):  
Time Course ◽  
Bathing Solution ◽  
Intercellular Spaces ◽  
Similar Time ◽  
Streaming Potentials ◽  
Osmotic Water ◽  
Lateral Intercellular Spaces ◽  
Transepithelial Voltage ◽  
Time Courses ◽  
Good Agreement

The mechanisms of apparent streaming potentials elicited across Necturus gallbladder epithelium by addition or removal of sucrose from the apical bathing solution were studied by assessing the time courses of: (a) the change in transepithelial voltage (Vms). (b) the change in osmolality at the cell surface (estimated with a tetrabutylammonium [TBA+]-selective microelectrode, using TBA+ as a tracer for sucrose), and (c) the change in cell impermeant solute concentration ([TMA+]i, measured with an intracellular double-barrel TMA(+)-selective microelectrode after loading the cells with TMA+ by transient permeabilization with nystatin). For both sucrose addition and removal, the time courses of Vms were the same as the time courses of the voltage signals produced by [TMA+]i, while the time courses of the voltage signals produced by [TBA+]o were much faster. These results suggest that the apparent streaming potentials are caused by changes of [NaCl] in the lateral intercellular spaces, whose time course reflects the changes in cell water volume (and osmolality) elicited by the alterations in apical solution osmolality. Changes in cell osmolality are slow relative to those of the apical solution osmolality, whereas lateral space osmolality follows cell osmolality rapidly, due to the large surface area of lateral membranes and the small volume of the spaces. Analysis of a simple mathematical model of the epithelium yields an apical membrane Lp in good agreement with previous measurements and suggests that elevations of the apical solution osmolality elicit rapid reductions in junctional ionic selectivity, also in good agreement with experimental determinations. Elevations in apical solution [NaCl] cause biphasic transepithelial voltage changes: a rapid negative Vms change of similar time course to that of a Na+/TBA+ bi-ionic potential and a slow positive Vms change of similar time course to that of the sucrose-induced apparent streaming potential. We conclude that the Vms changes elicited by addition of impermeant solute to the apical bathing solution are pseudo-streaming potentials, i.e., junctional diffusion potentials caused by salt concentration changes in the lateral intercellular spaces secondary to osmotic water flow from the cells to the apical bathing solution and from the lateral intercellular spaces to the cells. Our results do not support the notion of junctional solute-solvent coupling during transepithelial osmotic water flow.

STUDIES OF THE CULTURE OF ATROPELLIS PINIPHILA

1961 ◽  
Vol 39 (6) ◽  
pp. 1521-1529 ◽  
Author(s):  
J. C. Hopkins
Keyword(s):  
Relative Humidity ◽  
Lodgepole Pine ◽  
Carbon And Nitrogen ◽  
Optimum Ph ◽  
Ammonium Succinate ◽  
Cardinal Temperatures

Isolates of Atropellis piniphila were grown from single ascospores, and from cankers on lodgepole pine. A variety of media were tested for their capacity to support growth of the isolates. Descriptions of cultural and microscopical characters were prepared. Endoconidia were produced abundantly by most of the isolates after growth at 50%, or higher, relative humidity, but they were absent from most of the cultures which had been grown at 10% relative humidity. Attempts to grow apothecia in culture were unsuccessful. The cardinal temperatures for growth occurred at 4°, 18°, and at 24 °C. The optimum pH for growth in buffered media occurred at between 3.0 and 4.0. In media containing varying concentrations of carbon and nitrogen, growth was maximal on those containing 4% dextrose and 0.4% ammonium succinate. Of seven vitamins tested, a deficiency for thiamine alone was demonstrated.

scholarly journals Sodium and calcium currents in dispersed mammalian septal neurons.

1991 ◽  
Vol 97 (2) ◽  
pp. 303-320 ◽  
Author(s):  
A Castellano ◽  
J López-Barneo
Keyword(s):  
Time Constant ◽  
Time Course ◽  
Calcium Currents ◽  
Closing Time ◽  
Patch Clamp Technique ◽  
Average Value ◽  
Time To Peak ◽  
Time Courses ◽  
Fast Activation ◽  
Septal Neurons

Voltage-gated Na+ and Ca2+ conductances of freshly dissociated septal neurons were studied in the whole-cell configuration of the patch-clamp technique. All cells exhibited a large Na+ current with characteristic fast activation and inactivation time courses. Half-time to peak current at -20 mV was 0.44 +/- 0.18 ms and maximal activation of Na+ conductance occurred at 0 mV or more positive membrane potentials. The average value was 91 +/- 32 nS (approximately 11 mS cm-2). At all membrane voltages inactivation was well fitted by a single exponential that had a time constant of 0.44 +/- 0.09 ms at 0 mV. Recovery from inactivation was complete in approximately 900 ms at -80 mV but in only 50 ms at -120 mV. The decay of Na+ tail currents had a single time constant that at -80 mV was faster than 100 microseconds. Depolarization of septal neurons also elicited a Ca2+ current that peaked in approximately 6-8 ms. Maximal peak Ca2+ current was obtained at 20 mV, and with 10 mM external Ca2+ the amplitude was 0.35 +/- 0.22 nA. During a maintained depolarization this current partially inactivated in the course of 200-300 ms. The Ca2+ current was due to the activity of two types of conductances with different deactivation kinetics. At -80 mV the closing time constants of slow (SD) and fast (FD) deactivating channels were, respectively, 1.99 +/- 0.2 and 0.11 +/- 0.03 ms (25 degrees C). The two kinds of channels also differed in their activation voltage, inactivation time course, slope of the conductance-voltage curve, and resistance to intracellular dialysis. The proportion of SD and FD channels varied from cell to cell, which may explain the differential electrophysiological responses of intracellularly recorded septal neurons.

scholarly journals Mechanisms of autoantibody production in autoimmune MRL mice.

1980 ◽  
Vol 152 (5) ◽  
pp. 1302-1310 ◽  
Author(s):  
D S Pisetsky ◽  
G A McCarty ◽  
D V Peters
Keyword(s):  
Antibody Response ◽  
Time Course ◽  
Fundamental Difference ◽  
Autoantibody Production ◽  
Quantitative Expression ◽  
Autoantibody Response ◽  
Time Courses ◽  
Antibody Levels

The quantitative expression of anti-DNA and anti-Sm antibodies has been investigated in autoimmune MRL-lpr/lpr and MRL-+/+ mice. Anti-Sm antibodies were detected in sera from 21/23 lpr/lpr and 10/16 +/+ mice, with individual animals showing striking variation in the time-course and magnitude of this autoantibody response. The peak antibody levels of the responding animals of each substrain did not differ significantly. For anti-DNA antibody, a different pattern of responsiveness was observed. Individual animals of each substrain produced very similar responses in terms of the magnitude and time-course of serum anti-DNA antibody. The differences in the peak levels of the two substrains were highly significant, with lpr/lpr mice demonstrating a much greater anti-DNA antibody response than +/+ mice. In lpr/lpr mice tested for both autoantibody systems, serum anti-DNA and anti-Sm antibodies showed distinct time-courses. These studies indicate that anti-DNA and anti-Sm antibodies are expressed independently in MRL mice, with the expression of anti-DNA, but not anti-Sm antibody markedly influenced by the presence of the 1pr gene. A fundamental difference in the mechanisms involved in the generation of anti-DNA and anti-Sm antibodies is suggested by the quantitative pattern of the two responses.

scholarly journals The atypical cation-conduction and gating properties of ELIC underscore the marked functional versatility of the pentameric ligand-gated ion-channel fold

2015 ◽  
Vol 146 (1) ◽  
pp. 15-36 ◽  
Author(s):  
Giovanni Gonzalez-Gutierrez ◽  
Claudio Grosman
Keyword(s):  
Quaternary Ammonium ◽  
Time Course ◽  
Three Dimensional ◽  
Mouse Muscle ◽  
Current Decay ◽  
Quaternary Ammonium Cations ◽  
Inward Currents ◽  
Time Courses ◽  
Extracellular Side ◽  
Invariant Functional

The superfamily of pentameric ligand-gated ion channels (pLGICs) is unique among ionotropic receptors in that the same overall structure has evolved to generate multiple members with different combinations of agonist specificities and permeant-ion charge selectivities. However, aside from these differences, pLGICs have been typically regarded as having several invariant functional properties. These include pore blockade by extracellular quaternary-ammonium cations in the micromolar-to-millimolar concentration range (in the case of the cation-selective members), and a gain-of-function phenotype, which manifests as a slower deactivation time course, as a result of mutations that reduce the hydrophobicity of the transmembrane pore lining. Here, we tested this notion on three distantly related cation-selective members of the pLGIC superfamily: the mouse muscle nicotinic acetylcholine receptor (nAChR), and the bacterial GLIC and ELIC channels. Remarkably, we found that, whereas low millimolar concentrations of TMA+ and TEA+ block the nAChR and GLIC, neither of these two quaternary-ammonium cations blocks ELIC at such concentrations; instead, both carry measurable inward currents when present as the only cations on the extracellular side. Also, we found that, whereas lidocaine binding speeds up the current-decay time courses of the nAChR and GLIC in the presence of saturating concentrations of agonists, the binding of lidocaine to ELIC slows this time course down. Furthermore, whereas mutations that reduce the hydrophobicity of the side chains at position 9′ of the M2 α-helices greatly slowed the deactivation time course of the nAChR and GLIC, these mutations had little effect—or even sped up deactivation—when engineered in ELIC. Our data indicate that caution should be exercised when generalizing results obtained with ELIC to the rest of the pLGICs, but more intriguingly, they hint at the possibility that ELIC is a representative of a novel branch of the superfamily with markedly divergent pore properties despite a well-conserved three-dimensional architecture.

scholarly journals Dynamic Change in Cells Expressing IL-1β in Rat Hippocampus after Status Epilepticus

2014 ◽  
Vol 5 ◽  
pp. JCM.S13738 ◽  
Author(s):  
Satoru Sakuma ◽  
Daisuke Tokuhara ◽  
Hiroshi Otsubo ◽  
Tsunekazu Yamano ◽  
Haruo Shintaku
Keyword(s):  
Status Epilepticus ◽  
Cellular Localization ◽  
Wistar Rats ◽  
Time Course ◽  
Dynamic Change ◽  
Chronic Phase ◽  
Pyramidal Cells ◽  
Reactive Astrocytes ◽  
Time Courses ◽  
Ca3 Pyramidal Cells

Background The time course of cytokine dynamics after seizure remains controversial. Here we evaluated the changes in the levels and sites of interleukin (IL)-1β expression over time in the hippocampus after seizure. Methods Status epilepticus (SE) was induced in adult Wistar rats by means of intraperitoneal injection of kainic acid (KA). Subsequently, the time courses of cellular localization and IL-1β concentration in the hippocampus were evaluated by means of immunohistochemical and quantitative assays. Results On day 1 after SE, CA3 pyramidal cells showed degeneration and increased IL-1β expression. In the chronic phase (>7 days after SE), glial fibrillary acidic protein (GFAP)–-positive reactive astrocytes–-appeared in CA1 and became IL-1β immunoreactive. Their IL-1β immunoreactivity increased in proportion to the progressive hypertrophy of astrocytes that led to gliosis. Quantitative analysis showed that hippocampal IL-1β concentration progressively increased during the acute and chronic phases. Conclusion IL-1β affects the hippocampus after SE. In the acute phase, the main cells expressing IL-1β were CA3 pyramidal cells. In the chronic phase, the main cells expressing IL-1β were reactive astrocytes in CA1.

Biosurfactant production and its effects on solubilization activity of phenanthrene: a longitudinal study

2016 ◽  
Vol 74 (3) ◽  
pp. 580-585
Author(s):  
Masoumeh Golshan ◽  
Maryam Dastoorpour ◽  
Roshanak Rezaei Kalantary
Keyword(s):  
Time Course ◽  
Inoculum Size ◽  
Biosurfactant Production ◽  
Practical Application ◽  
Time Intervals ◽  
Initial Inoculum ◽  
Bacterial Inoculum ◽  
Polycyclic Aromatic ◽  
The Mean ◽  
Time Course Study

Pseudomonas facilis and Pseudomonasspp., isolated on the basis of its ability to grow on polycyclic aromatic hydrocarbon, was assayed for biosurfactant production (BP) potentials by measuring the surface tension (ST) of the culture supernatant at different time intervals. The strains in three levels of initial inoculum size (OD600 nm = 0.5, 1, 1.5) were added to medium to determine if bacterial inoculum size affects solubilization of phenanthrene (PHE).The result showed that although the two strains reduced the mean ST to less than 34.12 mN m−1 at the end of day 6, mean solubilization activity of PHE reached 77.05 mg L−1 on the sixth day. There was a significant increase in BP over time (P = 0.008); reaching its peak, 157.84 mg L−1, at the end of the sixth day. Mean solubilization activity of PHE was not significantly different for the two strains (P = 0.216). The time-course study revealed that the ST reduction and BP potential was enhanced as inoculation size increased, leading to higher PHE solubility during the incubation time. However, the trend of increase in PHE solubility was not totally in the same way to cell growth and BP. It may be suggested that more bacterial density needs to be inoculated for practical application of effective bioremediation.

scholarly journals Optimal Conditions For Production Acidic D-Xylanase By Aspergillus niger in Submerged Fermentation

2011 ◽  
Vol 5 (3) ◽  
pp. 14-21
Author(s):  
Muhamed Omar Abdulatif ◽  
Hyder H. Assmaeel ◽  
Raghad kadhim Obeid ◽  
Ayat Adnan Abbas
Keyword(s):  
Aspergillus Niger ◽  
Rice Husk ◽  
Enzyme Production ◽  
Inoculum Size ◽  
Optimal Conditions ◽  
Optimum Conditions ◽  
Xylanase Production ◽  
Primary Isolation ◽  
Optimum Ph ◽  
Optimum Period

he Xylanase producing strain Aspergillus niger was isolated from soil on potato dextrose agar in the presence of xylan as its first substrate for primary isolation, and then grown under liquid medium fermentation in the presence of crude xylan (rice husk) to produce D-Xylanase. the optimum conditions were determined as follows: the Optimum pH for xylanase production was found pH 5.0, xylanase was induced by xylan (rice husk) 0.1% and the production was (61.221 U/ml) and nitrogen source Yeast extract recorded highest enzyme production( 89.71 U/ml), and repressed by carbon source xylose the highest enzyme production (88.69 U/ml). The optimum temperature was 40°с for xylanase production was (35.15 U/ml), the optimum period after 7 days of incubation was (52.33 U/ml) ,the optimum substrate concentration 0.1% was (45.95 U/ml), and the optimum inoculum size was 1 x 106 (spore /ml) recorded (57.19 U/ml ).

scholarly journals Changes in blood hemoglobin and blood gases PaO2 and PaCO2 in severe COPD over a three-year telemonitored program of long-term oxygen treatment

2012 ◽  
Vol 7 ◽  
Author(s):  
Roberto W. Dal Negro ◽  
Silvia Tognella ◽  
Luca Bonadiman ◽  
Paola Turco
Keyword(s):  
Time Course ◽  
Blood Gases ◽  
Wilcoxon Test ◽  
Background Information ◽  
First Year ◽  
Oxygen Treatment ◽  
Blood Hemoglobin ◽  
Time Courses ◽  
Severe Copd

Background: Information on the effects of long-term oxygen treatment (LTOT) on blood hemoglobin (Hb) in severe COPD are limited. The aim was to assess blood Hb values in severe COPD, and investigate the time-course of both Hb and blood gas changes during a 3-year telemetric LTOT. Methods: A cohort of 132 severe COPD patients (94 males; 71.4 years ± 8.8 sd), newly admitted to the tele-LTOT program, was investigated. Subjects were divided according to their original blood Hb: group A: <13 g/dL; group B: ≥13<15 g/dL; group C: ≥ 5<16 g/dL; group D: ≥16 g/dL. Blood Hb (g/dL), PaO2 and PaCO2 (mmHg), SaO2 (%), and BMI were measured at LTOT admission (t0), and at least quarterly over three years (t1-t3). Wilcoxon test was used to compare t0 vs. t1 values; linear regression to assess a possible Hb-BMI relationship; ANOVA to compare changes in Hb time-courses over the 3 years. Results: LTOT induced a systematic increase of PaO2, and changes were significant since the first year (from 52.1 mmHg± 6.6sd to 65.1 mmHg± 8.7 sd, p<0.001). Changes in SaO2 were quite similar. Comparable and equally significant trends were seen in all subgroups (p<0.001). PaCO2 dropped within the first year of LTOT (from 49.4 mmHg± 9.1sd to 45.9 mmHg ±7.5 sd, p<0.001): the t0-t1 comparison proved significant (p<0.01) only in subgroups with the highest basal Hb, who showed a further PaCO2 decline over the remaining two years (p<0.001). Hb tended to normalization during LTOT only in subgroups with basal Hb>15 g/dl (ANOVA p<0.001); anemic subjects (Hb<13 g/dl) ameliorated not significantly in the same period (ANOVA = 0.5). Survival was independent of the original blood Hb. Anemia and polyglobulia are differently prevalent in COPD, the latter being the most represented in our cohort. LTOT affected both conditions, but to a different extent and according to different time-courses. The most striking Hb improvement was in polyglobulic patients in whom also PaO2, PaCO2 and SaO2 dramatically improved. In anemic subjects effects were smaller and slower, oxygenation being equally ameliorated by LTOT. Conclusions: LTOT effects on Hb and PaCO2 are regulated by an Hb-dependent gradient which seems independent of the original impairment of blood gases and of effects on oxygenation.

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