The use of microorganisms to induce chemical modifications in organic molecules is a very useful tool in organic synthesis, to obtain biologically active substances. The fungus Cephalosporium aphidicola is known by its ability to hydroxylate several skeleton positions of many classes of organic compounds. In this work, the microbial transformation of ent-kaur-16-en-19-ol (1) by C. aphidicola, a...

Biosorption may be simply defined as the removal of substances from solution by biological material. Such substances can be organic and inorganic, and in gaseous, soluble or insoluble forms. Biosorption is a physico-chemical process and includes such mechanisms as absorption, adsorption, ion exchange, surface complexation and precipitation. Biosorption is a property of both living and dead orga...

Many studies tested different feed additives, among these additives, humic substances (HS) have been used in livestock and poultry diets. Humic substances commonly present in nature as they are created from the organic matter decomposition, and are normally found in the soil and natural water. Active components of HS consist of humic acid (HA), humus, ulmic acid, fulvic acid, humin and certain ...

For several years we carried out a follow-up of two patients with IgA mesangial glomerulonephritis with antecedents of exposure to toxic substances (cadmium and organic solvents). The first case involved a 47 year old male who was diagnosed with mesangial IgA glomerulonephritis eight years ago; he had been working for twelve years as a solderer. He had used metal bars containing 25% cadmium as ...

Role of humic acids (HA) in plant tissue culture as plant growth regulators has been reviewed. Humic acid is a principal component of humic substances, which are the most important organic constituents of the soil (humus). Humus is defined as the organic matter in soil, a mixture of partially and totally humified substances. Leonardite is the best source for humic acid and it is extracted by us...

Guaiacol was applied at two spots on the same cell of Nitella. At one spot it was dissolved in 0.01 M NaCl, at the other in 0.01 M CaCl(2) or BaCl(2). The effect was practically the same in all cases, i.e. a similar change of P.D. in a negative direction, involving a more or less complete loss of P.D. (depolarization). When hexylresorcinol was used in place of guaiacol the result was similar. T...

Microcosm studies have been carried out to find out the relative survival of Escherichia coli and Salmonella typhimurium in a tropical estuary. Survival has been assessed in relation to the important self-purifying parameters such as biotic factors contained in the estuarine water, toxicity due to the dissolved organic and antibiotic substances in the water and the sunlight. The results reveale...