Effect of naphthalene and aqueous crude oil extracts on the green flagellate Chlamydomonas angulosa. IV. Decreases in cellular manganese and potassium

1981 ◽  
Vol 59 (5) ◽  
pp. 742-749 ◽  
Author(s):  
T. C. Hutchinson ◽  
J. A. Hellebust ◽  
C. Soto
Keyword(s):  
Crude Oil ◽  
Membrane Damage ◽  
Basal Medium ◽  
Initial Increase ◽  
Membrane Function ◽  
Manganese Uptake ◽  
Green Flagellate ◽  
Oil Extract ◽  
Short Time ◽  
In Cells

The effect of exposure to naphthalene and to aqueous extracts of crude oil on contents of manganese and potassium in cells of Chlamydomonas angulosa has been measured simultaneously by neutron activation analysis. Decreases of both manganese and potassium from treated cells commenced within a very short time of treatment initiation, and may be due to hydrocarbon-induced membrane damage. In control experiments, manganese uptake into cells was found to be light dependent, and potassium uptake was even more so. In cells treated with a 100% saturated naphthalene solution in Bold's basal medium (BBM), little cellular manganese remained after 6 h of exposure and less than 2% was left within 24 h. Potassium loss was even more rapid and complete. Rates of loss for both elements in a 50% saturated naphthalene solution in BBM and in an aqueous crude oil extract were slower but showed a similar pattern. For potassium in both light or dark exposures, an initial increase in cellular content occurred. Sodium acetate was added to assess heterotrophic growth, and the effects of this addition on the loss of the two elements are discussed. Over a short time, it appeared to act as an alternative to light energy in restoring membrane function.

The effect of crude oil on the morphology of the green flagellate Chlamydomonas angulosa

1979 ◽  
Vol 57 (24) ◽  
pp. 2717-2728 ◽  
Author(s):  
C. Soto ◽  
T. C. Hutchinson ◽  
J. A. Hellebust ◽  
R. G. Sheath
Keyword(s):  
Crude Oil ◽  
Morphological Changes ◽  
Exponential Phase ◽  
Ultrastructural Changes ◽  
Cytoplasmic Vacuoles ◽  
Dense Deposits ◽  
Osmiophilic Granules ◽  
Green Flagellate ◽  
Oil Extract ◽  
Increased Activity

The morphological changes of Chlamydomonas angulosa induced by treatment with an aqueous crude oil extract (ACOE) have been studied and compared with normal cells in the exponential phase of growth. Observations of oil-treated cells under the light microscope showed an effect on flagellar length and on motility, an increased activity of the contractile vacuoles, and an increase in granulations. Cells so treated become surrounded by a transparent envelope. By electron microscopy, the progression of ultrastructural changes has been followed. These changes include: a widened space between the cell wall and the plasmalemma; distorted and disorganized chloroplast lamellae; a decrease in density of the osmiophilic granules; and the presence of electron-dense deposits inside the cytoplasmic vacuoles. Cells were found to possess the ability to recover from the above abnormalities within an 8-day incubation period. Such a recovery corresponds to resumption of motility, capacity for growth, and photosynthesis, as described in other work. Based both on appearance, and on comparisons with bacterial, fungal studies, and cytochemical studies, it is suggested that the osmiophilic granules are lipid in nature and may act as a hydrocarbon sink. A self-cleansing mechanism is also suggested for these granules.

Effect of naphthalene and aqueous crude-oil extracts on the green flagellate Chlamydomonas angulosa. VI. Phosphate uptake and retention

1985 ◽  
Vol 63 (4) ◽  
pp. 829-833 ◽  
Author(s):  
T. C. Hutchinson ◽  
C. Soto ◽  
J. A. Hellebust
Keyword(s):  
Crude Oil ◽  
Phosphate Uptake ◽  
Culture Media ◽  
Large Fraction ◽  
Basal Medium ◽  
Atomic Ratio ◽  
Net Uptake ◽  
Green Flagellate ◽  
Saturated Media ◽  
Reactive Phosphorus

Chlamydomonas angulosa when grown in normal Bold's basal medium (BBM) (1.7 mM Pi) has a very high cell P content (120 fg-at. P∙cell−1) and low C: P atomic ratio (35: 1) and is only able to show net Pi uptake in media with Pi concentrations higher than 0.1 mM when grown in the light. The presence of light enhances net phosphate uptake or decreases net phosphate loss under all external Pi concentrations. Cells transferred to low-Pi media will, however, grow rapidly while reducing their cell P to almost 1/10 of the initial level, indicating that most of the cell P in cells grown in high-P media represents reserve P, probably in the form of polyphosphates. The presence of naphthalene and crude-oil components in the culture media decreases net uptake of Pi at high external Pi concentrations and increases the rate of Pi loss at low external concentrations. Naphthalene present at 100% saturation level in BBM causes rapid loss of a large fraction of cell P under all conditions tested. The phosphorus lost appears as reactive phosphorus in the medium, suggesting that cell polyphosphates are rapidly converted to Pi, which then leaks out of the cells in response to the presence of saturating naphthalene concentrations in the medium. BBM with 50% naphthalene saturation causes much less loss of cell P under most of the incubation conditions, and net uptake can take place at the highest external Pi concentrations tested in the light. Media saturated with crude oil are even less effective than 50% naphthalene saturated media in causing P efflux, or in reducing net Pi uptake, although at low external P concentrations, uptake of P is decreased compared with the control.

Effect of naphthalene and aqueous crude-oil extracts on the green flagellate Chlamydomonas angulosa. VII. Nitrate and methylamine uptake and retention

1985 ◽  
Vol 63 (4) ◽  
pp. 834-840 ◽  
Author(s):  
J. A. Hellebust ◽  
C. Soto ◽  
T. C. Hutchinson
Keyword(s):  
Crude Oil ◽  
Nitrate Uptake ◽  
Prolonged Exposure ◽  
Basal Medium ◽  
Transport Activity ◽  
Uptake Capacity ◽  
Short Term ◽  
Initial Uptake Rate ◽  
Green Flagellate ◽  
Saturated Media

Chlamydomonas angulosa grows equally well on nitrate and ammonium as sources of nitrogen. The presence of ammonium decreases nitrate uptake by less than 10% in short-term experiments. The presence of nitrate has no significant effect on short-term uptake of the ammonium analogue methylamine. Cells grown in nitrate media possess considerable methylamine uptake capacity during early exponential growth. This uptake capacity falls rapidly as the cells enter the declining growth phase. When cells are transferred to nitrogen-deficient media, the uptake capacity for methylamine increases threefold to fourfold in 24 h. The half-saturation constants (Km) for nitrate and methylamine uptake of this alga are 0.4 mM and 90 μM, respectively. When C. angulosa cells are transferred from control Bolds basal medium (BBM) to 50% naphthalene saturated or aqueous crude oil saturated media, the initial uptake rate for nitrate increases by a factor of two or decreases by a factor of one-third, respectively, as compared with that of cells transferred to control BBM. However, cells incubated in closed incubation systems with naphthalene or aqueous crude oil saturated media for 3 days lose nitrate when resuspended in control media. Cells transferred to media containing naphthalene up to 20% saturation show no immediate decrease in methylamine transport, while higher naphthalene concentrations cause an immediate decrease in transport activity. However, cells incubated in 50% naphthalene saturated media in a closed system for 2–4 h actually show increased methylamine transport activity when the incubation system is opened to allow escape of the hydrocarbon. Prolonged exposure to 50% naphthalene saturated media, however, causes progressive loss of transport activity.

Manganese as a site factor for epiphytic lichens

2005 ◽  
Vol 37 (5) ◽  
pp. 409-423 ◽  
Author(s):  
Markus HAUCK ◽  
Alexander PAUL
Keyword(s):  
New York ◽  
New York State ◽  
Membrane Damage ◽  
Coniferous Forests ◽  
Epiphytic Lichens ◽  
Mn Toxicity ◽  
Site Factor ◽  
Manganese Uptake ◽  
A Site ◽  
Mn Concentrations

Decreasing abundance of epiphytic lichens with increasing Mn supply from the substratum or from stemflow was found in several coniferous forests of Europe (Germany) as well as western (Montana, British Columbia) and eastern North America (New York State). Experiments carried out with Hypogymnia physodes and other species of chloro- and cyano-lichens suggest that these correlations are causal. High Mn concentrations e.g. reduce chlorophyll concentrations, chlorophyll fluorescence and degrade the chloroplast in lichen photobionts. Excess Mn inhibits the growth of soredia of H. physodes and causes damage in the fine- and ultra-structure of the soredia. Adult lichen thalli remain structurally unaffected by Mn. Manganese uptake does not result in membrane damage. Calcium, Mg, Fe and perhaps also Si alleviate Mn toxicity symptoms in H. physodes. Lecanora conizaeoides is not sensitive to Mn in laboratory experiments or in the field. The data suggest that high Mn concentrations are an important site factor for epiphytic lichens in coniferous forests that until recently has been overlooked. Manganese reaching the microhabitat of epiphytic lichens is primarily soil-borne and is usually not derived from pollution.

Oxygen consumption rate of shrimp exposed to crude oil extract

1982 ◽  
Vol 13 (7) ◽  
pp. 230-233 ◽  
Author(s):  
Susanne Pihl Baden
Keyword(s):  
Oxygen Consumption ◽  
Crude Oil ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Oil Extract

ANALYSIS OF CRITICAL SHORT-TIME LANGEVIN DYNAMICS IN TWO-DIMENSIONAL ϕ4 THEORY ON THE BASIS OF A HIGHER-ORDER ALGORITHM

2009 ◽  
Vol 20 (05) ◽  
pp. 735-745
Author(s):  
TSUYOSHI OTOBE ◽  
HIROMICHI NAKAZATO ◽  
KEISUKE OKANO ◽  
KAZUYA YUASA ◽  
NOZOMU HATTORI
Keyword(s):  
Critical Point ◽  
Langevin Dynamics ◽  
Initial Increase ◽  
Two Dimensional ◽  
Relaxation Dynamics ◽  
Time Dynamics ◽  
Time Scaling ◽  
Langevin Simulation ◽  
Short Time ◽  
Order Algorithm

We investigate the critical short-time scaling of the two-dimensional lattice ϕ4 field theory with a Langevin dynamics. Starting from a "hot" initial configuration but with a small magnetization, the critical initial increase of the magnetization is observed, through which we determine the critical point. From the short-time relaxation dynamics of various quantities at the critical point obtained, the dynamic critical exponents θ, z and the static exponent β/ν are evaluated. In executing a Langevin simulation, an appropriate discretization method with respect to the time degree of freedom becomes essentially important to be adopted and we show that the well-known second-order form of discretized Langevin equation works well to investigate the short-time dynamics.

scholarly journals Microampere electric currents caused bacterial membrane damage and two-way leakage in short time

2020 ◽  
Author(s):  
V R Krishnamurthi ◽  
A Rogers ◽  
J Peifer ◽  
I Niyonshuti ◽  
J Chen ◽  
...  
Keyword(s):  
Small Molecules ◽  
Single Molecule ◽  
Propidium Iodide ◽  
Membrane Damage ◽  
Bacterial Membrane ◽  
Electric Currents ◽  
Localization Microscopy ◽  
Propidium Iodide Staining ◽  
Short Time ◽  
Single Molecule Localization Microscopy

AbstractPhysical agents such as low electric voltages and currents have recently gained attention for antimicrobial treatment due to their bactericidal capability. Although microampere electric currents were shown to suppress the growth of bacteria, it remains unclear to what extent the microampere currents damage bacterial membrane. Here, we investigated the membrane damage and two-way leakage caused by microampere electric currents (≤ 100 μA) in a short time (30 min). Based on MitoTracker staining, propidium iodide staining, filtration assays, and quantitative single-molecule localization microscopy, we found that microampere electric currents caused significant membrane damages and allowed two-way leakages of ions, small molecules and proteins. This study paves the way to new development and antibiotic applications of ultra-low electric voltages and currents.Statement of SignificancePrevious studies showed that treating bacteria with milliampere electric currents for 72 hours led to significant damages of the bacterial membrane. However, it remains unclear to what extent membrane damages and two-way (i.e. inward and outward) leakages are caused by lower electric currents in a shorter time. In this work, we set out to answer this question. We carried out several assays on the bacteria treated by microampere electric currents of ≤ 100 μA for 30 min, including MitoTracker staining, propidium iodide staining, filtration assays, and quantitative single-molecule localization microscopy. We found and quantified that the membrane damages were caused by microampere electric currents in half an hour and allowed two-way leakages of ions, small molecules, and proteins.

scholarly journals Assessment of Biodiesel Fuel Potentials of Seed Crude Oil Extracts of Balanites aegyptiaaca (L.) Del

2020 ◽  
Vol 24 (8) ◽  
pp. 1467-1473
Author(s):  
M.S. Chomini ◽  
A.J. Daspan ◽  
C. Kambai ◽  
A.E. Chomini ◽  
E.A. Bassey ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Crude Oil ◽  
Large Scale ◽  
Seed Oil ◽  
Cetane Number ◽  
Chemical Properties ◽  
Calorific Value ◽  
Biodiesel Fuel ◽  
Test Plant ◽  
Oil Extract

Study on assessmentof biodiesel fuel potentials of seed crude oil extracts of Balanites aegyptiaaca (L.) Del was carriedout. Standard methods of the Association of Official and Analytical Chemist (AOAC) were adopted to evaluate the proximate, physico-chemical properties and fatty acid  compositions of crude seed oil extracts of the test plant. The proximate constituents of the crude seed oil extract gave crude protein (22.09%), crude fat (56.75%), moisturecontent (1.35%), ash (4.70%), crudefiber (12.75%) and carbohydrate (2.36%). The crude oil physicochemical properties included saponification value(216.439mgKOH/g), peroxide value(4.84meq/kg), acid value(2.18mgKOH/g), iodine value(77.08g/100g), viscosity  value(150.3@30°C) and cetane number(54.08), refractive index(1.487 @30°C), relative density (0.949g/cm3) while calorific value was 39.03(MJ/kg). The fatty acids composition of crude kernel oil extract of B. aegyptiaca indicated the presence of four (4) fatty acids, with relative percentage abundance (RPA) in the order of 67.17% (9,12-Octadecanoic acid (C19 H3402)) > 16.22% (Pentadecanoic acid (C17H3402)) > 11.8kg% (Heptacosanoic acid (C28H5602)) > 4.72% (Oleic acid(C18H3402)). These properties conferred relative prospects on the crude oil of the test plant as a suitable  potential biodiesel substrate and consequently, large scale aforestation efforts be renewed, to guarantee ready availability of the raw materials. Keywords: Balanites aegyptiaca, Biodiesel, proximate, physicochemical, crude seed oil extracts

Effect of naphthalene and aqueous crude oil extracts on the green flagellate Chlamydomonas angulosa. II. Photosynthesis and the uptake and release of naphthalene

1975 ◽  
Vol 53 (2) ◽  
pp. 118-126 ◽  
Author(s):  
C. Soto ◽  
J. A. Hellebust ◽  
T. C. Hutchinson
Keyword(s):  
Crude Oil ◽  
Photosynthetic Capacity ◽  
Open Systems ◽  
Complete Loss ◽  
Original Medium ◽  
Rate Of Recovery ◽  
Green Flagellate ◽  
Saturated Media ◽  
Closed Systems ◽  
Actual Loss

Comparisons have been made of the effects of crude oil extracts and naphthalene on the photosynthesis of the alga Chlamydomonas angulosa. The addition of the hydrocarbon naphthalene to C. angulosa cultures causes an immediate and almost complete loss of photosynthetic capacity. When cells that have been incubated in closed systems containing naphthalene-saturated media are transferred to open systems which allow loss by volatilization of naphthalene, the rate of recovery of photosynthesis is inversely proportional to the length of incubation in the closed system with naphthalene. Incubation of cells in open systems with media containing aqueous crude oil extracts has no significant effect on their photosynthetic capacity as compared with that of cells incubated in control media. However, the photosynthetic capacity is decreased when cells are incubated in closed systems with media containing aqueous crude oil extracts. This is followed by a gradual recovery with time of incubation after treatment in the closed systems.Experiments using labelled naphthalene indicate that C. angulosa cells accumulate naphthalene from the medium in closed systems for up to 7 days. When such cells are transferred to fresh media not containing naphthalene, there is an almost immediate loss of the aromatic hydrocarbon from the cells. However, when cells are retained in their original medium after opening the culture system to allow naphthalene to escape, the decrease in naphthalene content per cell appears dependent upon resumption of cell division and occurs in a stepwise manner, which suggests cell retention rather than an actual loss of naphthalene to the medium.

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