The mode of action of potassium ions on the leukophores of a freshwater teleost,Oryzias latipes

1978 ◽  
Vol 205 (3) ◽  
pp. 413-421 ◽  
Author(s):  
Tetsuro Iga
Keyword(s):  
Mode Of Action ◽  
Oryzias Latipes ◽  
Potassium Ions ◽  
Freshwater Teleost

scholarly journals Proposed mechanism of antibacterial mode of action of Caesalpinia bonducella seed oil against food-borne pathogens

2016 ◽  
Vol 11 (1) ◽  
pp. 257
Author(s):  
Shruti Shukla ◽  
Rajib Majumder ◽  
Laxmi Ahirwal ◽  
Archana Mehta
Keyword(s):  
Electrical Conductivity ◽  
Mode Of Action ◽  
Seed Oil ◽  
Membrane Integrity ◽  
Extracellular Atp ◽  
Potassium Ions ◽  
Food Borne ◽  
Absorbing Materials ◽  
Caesalpinia Bonducella ◽  
Relative Electrical Conductivity

<p class="Abstract">The antibacterial mechanism of action of <em>Caesalpinia bonducella</em> seed oil on membrane permeability of <em>Listeria monocytogenes</em> NCIM 24563 (MIC: 2 mg/mL) and <em>Escherichia coli</em> ATCC 25922 (MIC: 4 mg/mL) was determined by measuring the extracellular ATP concentration, release of 260-nm absorbing materials, leakage of potassium ions and measurement of relative electrical conductivity of the bacterial cells treated at MIC concentration. Its mode of action on membrane integrity was confirmed by release of extracellular ATP (1.42 and 1.33 pg/mL), loss of 260-nm absorbing materials (4.36 and 4.19 optical density), leakage of potassium ions (950 and 1000 mmol/L) and increase in relative electrical conductivity (12.6 and 10.5%) against food-borne pathogenic bacteria <em>L. monocytogenes</em> and <em>E. coli</em>, respectively. These findings propose that <em>C. bonducella</em> oil compromised its mode of action on membrane integrity, suggesting its enormous food and pharmacological potential.</p><p> </p>

scholarly journals The Mode of Action of Polyene Antibiotics; Induced Potassium Leakage in Candida albicans

Microbiology ◽  
2000 ◽  
Vol 81 (2) ◽  
pp. 325-330 ◽  
Author(s):  
S. M. HAMMOND ◽  
P. A. LAMBERT ◽  
B. N. KLIGER
Keyword(s):  
Candida Albicans ◽  
Mode Of Action ◽  
Liquid Membrane ◽  
Potassium Ions ◽  
Common Site ◽  
Potassium Efflux ◽  
Polyene Antibiotics ◽  
Site Of Action ◽  
Sensitive Electrode ◽  
Potassium Leakage

Summary: With a liquid membrane potassium-sensitive electrode it was shown that lethal concentrations of the polyene antibiotics amphotericin B, candicidin and nystatin caused leakage of 90% of non-bound potassium ions from Candida albicans. Accurate and rapid determinations of rates of potassium leakage were made directly in suspensions of Candida. Leakage patterns for the three polyenes were very similar, suggesting a common site of action. Differences were noted in the rates of potassium efflux with organisms from cultures of differing ages.

scholarly journals Characterization of lactic acid bacterium Pediococcus pentosaceus 4I1 from fresh water fish Zacco koreanus and its antibacterial mode of action

2016 ◽  
Author(s):  
Vivek K. Bajpai ◽  
Jeong-Ho Han ◽  
Irfan A. Rather ◽  
Rajib Majumder ◽  
Gyeong-Jun Nam ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacterium ◽  
Mode Of Action ◽  
Membrane Integrity ◽  
Potassium Ions ◽  
Fresh Water Fish ◽  
Pediococcus Pentosaceus ◽  
Water Fish ◽  
Relative Electrical Conductivity

The present study aimed to characterize a lactic acid bacterium Pediococcus pentosaceus 4I1, isolated from the intestine of fresh water fish sample Zacco koreanus. Biochemical analysis using the API 50 CHL kit and molecular characterization of 4I1 revealed its identity as a lactic acid bacterium Pediococcus pentosaceus 4I1. Further, cell free supernatant (CFS) of P. pentosaceus 4I1 exhibited significant (p<0.05) antibacterial effect as diameters of inhibition zones (16.5–20.4 mm) against the tested foodborne pathogenic bacteria with minimum inhibitory (MIC) and minimum bactericidal (MBC) concentration values found in the range of 250-500 and 500-1,000 µg/mL, respectively. Further, to confirm the efficacy of 4I1 on membrane permeability against foodborne pathogens, antibacterial mode of action of CFS of P. pentosaceus 4I1 against two selected bacteria Staphylococcus aureus KCTC-1621 (gram-positive) and Escherichia coli O157:H7 (gram-negative) was determined by measuring cell viable count, release of 260-nm absorbing materials, leakage of potassium ions and measurement of relative electrical conductivity of the bacterial cells treated at MIC concentration. The CFS of P. pentosaceus 4I1 revealed its mode of action on membrane integrity as confirmed by reduction in viable cell count, increased release of potassium ions (900 and 800 mM/L), loss of 260-nm absorbing materials (3.99 and 3.77 OD), and increase in relative electrical conductivity (9.9 and 9.7%) against the tested bacteria S. aureus KCTC-1621 and E. coli O157:H7, respectively. The above findings hypothesize that P. pentosaceus 4I1 compromised its mode of action on membrane integrity, suggesting its enormous potential in food and pharma industries.

scholarly journals Characterization of lactic acid bacterium Pediococcus pentosaceus 4I1 from fresh water fish Zacco koreanus and its antibacterial mode of action

2016 ◽  
Author(s):  
Vivek K. Bajpai ◽  
Jeong-Ho Han ◽  
Irfan A. Rather ◽  
Rajib Majumder ◽  
Gyeong-Jun Nam ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacterium ◽  
Mode Of Action ◽  
Membrane Integrity ◽  
Potassium Ions ◽  
Fresh Water Fish ◽  
Pediococcus Pentosaceus ◽  
Water Fish ◽  
Relative Electrical Conductivity

The present study aimed to characterize a lactic acid bacterium Pediococcus pentosaceus 4I1, isolated from the intestine of fresh water fish sample Zacco koreanus. Biochemical analysis using the API 50 CHL kit and molecular characterization of 4I1 revealed its identity as a lactic acid bacterium Pediococcus pentosaceus 4I1. Further, cell free supernatant (CFS) of P. pentosaceus 4I1 exhibited significant (p<0.05) antibacterial effect as diameters of inhibition zones (16.5–20.4 mm) against the tested foodborne pathogenic bacteria with minimum inhibitory (MIC) and minimum bactericidal (MBC) concentration values found in the range of 250-500 and 500-1,000 µg/mL, respectively. Further, to confirm the efficacy of 4I1 on membrane permeability against foodborne pathogens, antibacterial mode of action of CFS of P. pentosaceus 4I1 against two selected bacteria Staphylococcus aureus KCTC-1621 (gram-positive) and Escherichia coli O157:H7 (gram-negative) was determined by measuring cell viable count, release of 260-nm absorbing materials, leakage of potassium ions and measurement of relative electrical conductivity of the bacterial cells treated at MIC concentration. The CFS of P. pentosaceus 4I1 revealed its mode of action on membrane integrity as confirmed by reduction in viable cell count, increased release of potassium ions (900 and 800 mM/L), loss of 260-nm absorbing materials (3.99 and 3.77 OD), and increase in relative electrical conductivity (9.9 and 9.7%) against the tested bacteria S. aureus KCTC-1621 and E. coli O157:H7, respectively. The above findings hypothesize that P. pentosaceus 4I1 compromised its mode of action on membrane integrity, suggesting its enormous potential in food and pharma industries.

scholarly journals Mechanistic Properties of the Two-Component Bacteriocin Lactococcin G

1998 ◽  
Vol 180 (1) ◽  
pp. 96-99 ◽  
Author(s):  
Gert Moll ◽  
Håvard Hildeng-Hauge ◽  
Jon Nissen-Meyer ◽  
Ingolf F. Nes ◽  
Wil N. Konings ◽  
...  
Keyword(s):  
Cell Surface ◽  
Lactococcus Lactis ◽  
Target Cell ◽  
Mode Of Action ◽  
Biologically Active ◽  
Target Cells ◽  
Potassium Ions ◽  
Monovalent Cations ◽  
Complementary Action ◽  
Two Component

ABSTRACT Lactococcin G is a bacteriocin whose activity depends on the complementary action of two peptides, termed α and β. Biologically active, synthetic lactococcin G was used to study the mode of action on sensitive cells of Lactococcus lactis. The α and β peptides can bind independently to the target cell surface, but activity requires the complementary peptide. Once bound to the cell surface, the peptides cannot be displaced to the surfaces of other cells. A complex of α and β peptides forms a transmembrane pore that conducts monovalent cations but not protons. Efflux of potassium ions is observed only above pH 5.0, and the rate of efflux increases steeply with the pH. The consequences of cation fluxes for the viability of the target cells are discussed.

Effects of 5-5'-Diphenyl-2-thiohydantoin (DPTH) and Thyroxine on the Ultrastructure and Chemical Composition of Rat Liver

1971 ◽  
Vol 29 ◽  
pp. 570-571
Author(s):  
E. A. Elfont ◽  
R. B. Tobin ◽  
D. G. Colton ◽  
M. A. Mehlman
Keyword(s):  
Chemical Composition ◽  
Rat Liver ◽  
Future Study ◽  
Mode Of Action ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Effective Inhibitor ◽  
Biochemical Effects ◽  
Glycerophosphate Dehydrogenase ◽  
Stimulation Of

Summary5,-5'-diphenyl-2-thiohydantoin (DPTH) is an effective inhibitor of thyroxine (T4) stimulation of α-glycerophosphate dehydrogenase in rat liver mitochondria. Because this finding indicated a possible tool for future study of the mode of action of thyroxine, the ultrastructural and biochemical effects of DPTH and/or thyroxine on rat liver mere investigated.Rats were fed either standard or DPTH (0.06%) diet for 30 days before T4 (250 ug/kg/day) was injected. Injection of T4 occurred daily for 10 days prior to sacrifice. After removal of the liver and kidneys, part of the tissue was frozen at -50°C for later biocheailcal analyses, while the rest was prefixed in buffered 3.5X glutaraldehyde (390 mOs) and post-fixed in buffered 1Z OsO4 (376 mOs). Tissues were embedded in Araldlte 502 and the sections examined in a Zeiss EM 9S.Hepatocytes from hyperthyroid rats (Fig. 2) demonstrated enlarged and more numerous mitochondria than those of controls (Fig. 1). Glycogen was almost totally absent from the cytoplasm of the T4-treated rats.

An ultrastructural study of sertoli cells in two geographically isolated populations of Aphanius dispar

1992 ◽  
Vol 50 (1) ◽  
pp. 548-549
Author(s):  
Taber A. Ba-Omar ◽  
Philip F. Prentis
Keyword(s):  
Ultrastructural Level ◽  
Uranyl Acetate ◽  
Freshwater Teleost ◽  
Isolated Populations ◽  
En Bloc ◽  
The North ◽  
Group A ◽  
Ultrathin Sections ◽  
Group B ◽  
Geographically Isolated

We have recently carried out a study of spermiogenic differentiation in two geographically isolated populations of Aphanius dispar (freshwater teleost), with a view to ascertaining variation at the ultrastructural level. The sampling areas were the Jebel Al Akhdar in the north (Group A) and the Dhofar region (Group B) in the south. Specimens from each group were collected, the testes removed, fixed in Karnovsky solution, post fixed in OsO, en bloc stained with uranyl acetate and then routinely processed to Agar 100 resin, semi and ultrathin sections were prepared for study.

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