STUDIES ON CHLORELLA VULGARIS. III. GROWTH OF CHLORELLA AND CHANGES IN THE HYDROGEN-ION AND AMMONIUM-ION CONCENTRATIONS IN SOLUTIONS CONTAINING NITRATE AND AMMONIUM NITROGEN

1940 ◽  
Vol 27 (9) ◽  
pp. 735-743 ◽  
Author(s):  
Robertson Pratt ◽  
Jane Fong
Keyword(s):  
Chlorella Vulgaris ◽  
Ammonium Nitrogen ◽  
Hydrogen Ion ◽  
Ammonium Ion ◽  
Ion Concentrations

scholarly journals The acidity of muscle during maintained contraction

1922 ◽  
Vol 93 (654) ◽  
pp. 406-410
Keyword(s):  
Manganese Dioxide ◽  
Hydrogen Ion ◽  
Ion Concentrations

In 1913, I described a method for recording changes in hydrogen-ion concentrations in tissues, by means of a manganese dioxide electrode in combination with a calomel electrode (1). By this method it was shown that the acidity of muscle probably increased at the same time as, or slightly before, the tension increased, and that the acidity decreased as the muscle relaxed (2). In a paper, which appeared as this note was being prepared for publication, Ritchie states that he has been unable to detect a variation in acidity by the use of manganese dioxide electrodes. I am inclined to think that his failure is due to the injury to the muscles on insertion of wires into its substance. In my own experiments the wires rest on the surface of the muscle.

scholarly journals Influence of Organic Ammonium Derivatives on the Equilibria Between of NH4+, NO2- and NO3- Ions in River Waters

2021 ◽  
Author(s):  
Petru Spataru
Keyword(s):  
River Water ◽  
Nitrogen Concentration ◽  
Inhibitory Effect ◽  
Ammonium Nitrogen ◽  
Ammonium Ion ◽  
Organic Radical ◽  
Stress Effect ◽  
River Waters ◽  
Carbon Radicals ◽  
Organic Amines

Abstract The braking effect of the ammonium derivatives on the natural aquatic environment varies dramatically with the number and nature of organic radical substitutions at nitrogen atom, particularly with their structure, composition and genesis. The most common discrepancy in their toxic effect are showing the natural and synthetic amines. For instance, the values of the maximum allowable concentration (MAC) of the derivatives of the natural origin for drinking water exceed the MAC of the synthetic ones by two orders. On the other hand, it has been found out that 1- naphtylamine (1-NA) inhibitory effect is associated to its toxicity. The Diethylamine (DEA) braking impact on the nitrification process is effectively lower than that of the toxicity. Our experiments show that the carbon-radicals of organic amines act as reducing agents. It is found that DEA decomposition leads to a high NH4+ ions (approx. 3.8 mg/L ammonium nitrogen) concentration in river water samples. By laboratory simulations two types of fixations by microbial organisms have been established: 1) absorption-desorption, the hydromicrobiotic reaction to ammonium (HMBRA) at the instantaneous increase of the concentration of ammonium ion in the river water (so-called shock/stress effect); 2) nitrogen fixation stimulated by a certain concentration (0.05mg/L) of a 1-NA and other amines.

scholarly journals THE RELATION OF THE PNEUMOCOCCUS TO HYDROGEN ION CONCENTRATION, ACID DEATH-POINT, AND DISSOLUTION OF THE ORGANISM

1919 ◽  
Vol 30 (4) ◽  
pp. 389-399 ◽  
Author(s):  
Frederick T. Lord ◽  
Robert N. Nye
Keyword(s):  
Hydrogen Ion ◽  
Ion Concentration ◽  
Direct Relation ◽  
Hydrogen Ion Concentration ◽  
Ion Concentrations ◽  
Cent Glucose ◽  
Fluid Media

1. In the growth and death of the pneumococcus in fluid media containing 1 per cent glucose the production of acid is the most important bactericidal factor. 2. 1 per cent glucose bouillon cultures of the pneumococcus allowed to grow and die out usually reach a final acidity of a pH of about 5.1. 3. At a hydrogen ion concentration of about 5.1 or higher, the pneumococcus does not survive longer than a few hours. 4. In hydrogen ion concentrations of about 6.8 to 7.4 the pneumococcus may live for at least many days. 5. In the intervening hydrogen ion concentrations, between 6.8 and 5.1, the pneumococcus is usually killed with a rapidity which bears a direct relation to the hydrogen ion concentration; i.e., the greater the acidity the more rapid is the death. 6. Cloudy suspensions of washed pneumococci in hydrogen ion concentrations varying from 8.0 to 4.0 show, after incubation, dissolution of organisms in lower hydrogen ion concentrations than about 5.0. This dissolution is most marked at about 5.0 to 6.0. Some dissolution also takes place toward the more alkaline end of the scale. No dissolution occurs at the most acid end of the scale.

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