Absence Of Ammonium Salts Research Articles

Degradation of the surfactant Cocamidopropyl betaine by two bacterial strains isolated from activated sludge

Cocamidopropyl betaine (CAPB) is an amphiphilic surfactant commonly used in a variety of personal care products and in some technical applications. The aim of the study was to obtain bacteria that utilized CAPB from a sample of municipal activated sludge, and to investigate the possible role such bacteria performed in surfactant degradation. The CAPB (300 mg l−1) degradation experiments involved the application of two isolated strains. Whilst tests in a mineral medium containing ammonium salt as a nitrogen source revealed almost complete mineralization of the compound in both strains during 4 days, the same process required more than 29 days of incubation under nitrogen-free conditions. Degradation assays and a series of growth tests with and without the source of nitrogen showed that Pseudomonas sp. FV proved to be the primary degrader of CAPB, capable of utilizing the alkyl chains of the surfactant. The other strain, Rhizobium sp. FM, ensured the degradation of intermediates originating from the primary biodegradation stage and, in the absence of ammonium salt, provided a supply of nitrogen to its microbial partner.

Determination of Potash in Fertilizers or Base Goods in Absence of Ammonium Salts and Organic Matter

Determination of Potash in Fertilizers or Base Goods in Absence of Ammonium Salts and Organic Matter

The Phosphate Nutrition of Plants

Much work has been done in America, on the Continent and in this country, to determine the effect of different finely-ground naturally-occurring phosphatic substances on plants of various natural orders, grown under differing conditions as to the character of the soil and the use of other nutrient substances. In a few cases results or conclusions appear to conflict. Not nearly so much attention has been devoted to the effect of artificially prepared insoluble salts of phosphoric acid on the growth of plants. When these are employed in the absence of ammonium salts, and acid soil substances, definite information should be obtained as to the powers possessed by plants themselves of utilizing insoluble phosphates. With the object of making a contribution to such knowledge, oats, peas and swede turnips were grown in artificial soils made up of white sand and pure chalk, and the particular salt of phosphoric acid under investigation. The other essential nutrient substances were supplied in a dilute solution of salts.