THE RELATION OF THE BACTERIOSTATIC ACTION OF CERTAIN DYES TO OXIDATION-REDUCTION PROCESSES

Oxidized indophenols and methylene blue are bacteriostatic for Pneumococcus and hemolytic streptococci of human and bovine origin, while the indigoes, malachite green and litmus are not toxic. 2-Chloroindophenol, the most positive of the indicators of oxidation-reduction potentials used, is also the only one to have a bacteriostatic action on cheese strains of Streptococcus hæmolyticus. Methylene blue and the indophenols are no longer bacteriostatic when present in a reduced form in a medium capable of maintaining them in such a condition. A comparison of these results with the growth in plain broth of the organisms studied suggests that the "inhibiting" dyes "poise" the medium at an oxidation potential outside the range in which the inhibited organisms can grow.

Download Full-text

Concerning the form of biochemically active vanadium

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1981.0025 ◽

1981 ◽

Vol 212 (1186) ◽

pp. 65-84 ◽

Cited By ~ 36

Keyword(s):

Transmembrane Potential ◽

Tridentate Ligands ◽

Vanadium Concentration ◽

Hydrated Form ◽

Reduction Processes ◽

Reduction Potentials ◽

Oxidation Reduction ◽

Descriptive Chemistry ◽

Kinetics Of ◽

Vanadium Ions

A survey has been made of the descriptive chemistry of vanadium as it pertains to physiological environments. Taking into account the vanadium concentration, pH, coordinating ligands and chelates, presence of other cations, oxidation-reduction potentials and the kinetics of the various vanadium-containing species, the following suggestions are made. Free vanadium ions will be monomeric. Monomeric vanadium(V) and vanadium(IV) will each exist in a specific hydrated form. Extracellular vanadium will be in the vanadate, V v , form. Intracellular vanadium will most likely be predominately in the vanadyl, V IV , form. Both extracellular vanadium(V) and intracellular vanadium(IV) will be bound to bi- or tridentate ligands if at all. If oxidation-reduction processes involving vanadium are fast relative to transmembrane transport, the transmembrane potential will not be coupled to the V V / V IV Nernstian potential.

Download Full-text

THE INITIATION OF GROWTH OF CERTAIN FACULTATIVE ANAEROBES AS RELATED TO OXIDATION-REDUCTION PROCESSES IN THE MEDIUM

Journal of Experimental Medicine ◽

10.1084/jem.49.4.559 ◽

1929 ◽

Vol 49 (4) ◽

pp. 559-573 ◽

Cited By ~ 14

Author(s):

René Dubos

Keyword(s):

Reduction Potential ◽

Bacterial Species ◽

Growth Conditions ◽

Critical Value ◽

Oxidation Potential ◽

Bacterial Cells ◽

Anaerobic Conditions ◽

Reduction Processes ◽

Oxidation Reduction ◽

Reducing Properties

The growth of many pathogenic organisms in plain meat infusion broth is possible only when a large inoculum is used. This requirement is much less strict when the broth cultures are incubated (a) under anaerobic conditions, (b) in fresh media very recently boiled or autoclaved, (c) in fresh media reduced by means of hydrogen, or to which small amounts of cysteine or of blood have been added. It is suggested that these findings can be accounted for by assuming that the bacterial species under consideration can multiply only in media the oxidation potential of which is below a critical value. The favorable growth conditions obtained by the procedures enumerated above may be attributed to the establishment of a proper reduction potential in the medium; the same result is obtained by using a large inoculum, owing to the reducing properties of bacterial cells.

Download Full-text

METHYLENE BLUE, POTASSIUM CYANIDE AND CARBON MONOXIDE AS INDICATORS FOR STUDYING THE OXIDATION-REDUCTION POTENTIALS OF DEVELOPING MARINE EGGS

Biological Bulletin ◽

10.2307/1538179 ◽

1943 ◽

Vol 84 (2) ◽

pp. 164-177 ◽

Cited By ~ 4

Author(s):

MATILDA MOLDENHAUER BROOKS

Keyword(s):

Methylene Blue ◽

Carbon Monoxide ◽

Potassium Cyanide ◽

Reduction Potentials ◽

Oxidation Reduction

Download Full-text

THE ROÔLE OF CARBOHYDRATES IN BIOLOGICAL OXIDATIONS AND REDUCTIONS. EXPERIMENTS WITH PNEUMOCOCCUS

Journal of Experimental Medicine ◽

10.1084/jem.50.2.143 ◽

1929 ◽

Vol 50 (2) ◽

pp. 143-160 ◽

Cited By ~ 2

Author(s):

René Dubos

Keyword(s):

Methylene Blue ◽

Bacterial Culture ◽

Reducing Power ◽

Side Reactions ◽

Thiol Compounds ◽

Reduction Potentials ◽

Oxidation Reduction ◽

Glucose System ◽

Synthetic Media ◽

Reduction Scale

The reducing power of plain broth cultures of Pneumococcus is largely dependent upon the presence in the medium at the time when the reduction test is performed of certain metabolites. The washed cells of Pneumococcus are able to reduce the various indicators of oxidation-reduction potentials in the presence of glucose. The relative velocity of reduction of these indicators is determined by the number of cells used in the test, the concentration of the dyes, and their position in the oxidation reduction scale. Oxidized thiol compounds (glutathione, cystine, oxidized thioglycollic acid) are likewise rapidly reduced by glucose in the presence of washed cells of Pneumococcus. This Pneumococcus-glucose system is able to form peroxide under aerobic conditions. Those substances which form peroxide in the presence of Pneumococcus cells are also the ones which Cole found to be active in changing hemoglobin into methemoglobin under the same conditions. The power of washed cells of Pneumococcus to reduce methylene blue in the presence of glucose is dependent on at least 2 constituents: one which can be readily removed from the cell by washing. Sugar-free meat infusion will function instead of it. The other is inactivated more slowly by the process of washing and is destroyed by 10 minutes heating at 55°C. The interreaction between the glucose and the cell seems to result in a fundamental reaction in which one molecule of glucose becomes able to reduce rapidly one molecule of methylene blue. The existence of side-reactions often obscures this ratio. The significance of these observations is considered in relation to the nature and mechanism of the "activation" of metabolites, the preparation of synthetic media, the phenomena of growth, and the meaning of the expression "reducing power of a bacterial culture."

Download Full-text

MEASUREMENT OF OXIDATION–REDUCTION CONDITIONS IN WHEAT LEAF SAP BY A POTENTIOMETRIC METHOD

Canadian Journal of Botany ◽

10.1139/b60-038 ◽

1960 ◽

Vol 38 (3) ◽

pp. 387-398 ◽

Cited By ~ 2

Author(s):

Rudolf Kaul ◽

Michael Shaw

Keyword(s):

Methylene Blue ◽

Redox System ◽

Platinum Electrodes ◽

Anaerobic Conditions ◽

Mature Leaves ◽

Reduction Potentials ◽

Oxidation Reduction ◽

Wheat Leaf ◽

Steady Level ◽

New System

Extracts from primary leaves of Little Club wheat, prepared under anaerobic conditions, gave oxidation–reduction potentials in the range of −180 mv to −140 mv at pH 6 when measured potentiometrically with prepolarized platinum electrodes. These poorly poised potentials are believed to represent a flavin system. By mixing mediators (e.g. methylene blue and riboflavin) with the extracts stable average potentials were achieved. These ranged from −70 to +70 mv. Coleoptiles and very young primary leaves exhibited relatively low average potentials, which climbed to a steady level in 8 to 10 days after sowing. This change was accompanied by a quantitative shift between three poising systems found in the leaves by redox titrations. The results suggested that ascorbic acid becomes the dominating redox system in extracts from mature leaves. At senescence, indicated by yellowing, a new system dominates the redox background. This exhibited quinonic properties.

Download Full-text