Abstract: A process is disclosed in which an amino acid-producing microorganism having an ability to assimilate lactic acid is aerobically cultivated in the presence of at least one lactic acid microorganism in an aqueous nutrient medium containing at least one carbohydrate which is assimilable by the lactic acid microorganism but nonassimilable or weakly assimilable by the amino acid-producing microorganism as the main carbon source and an accumulated amino acid is recovered from the culture broth. An industrially advantageous production of an amino acid has become feasible by utilizing inexpensive carbon sources or those organic substances in agricultural or livestock wastes that have heretofore not been effectively utilized.

Abstract: The microorganisms Micromonospora inyoensis 1550F-1G and M. purpurea strain 1124 each microbiologically convert tobramycin, kanamycin A, kanamycin B and dibekacin to their respective 3"-N-methyl and 3"-N-methyl-4"-C-methyl derivatives. The derivatives exhibit significant activity against representative gram positive and gram negative bacteria and may also be converted to other derivatives which have significant antibacterial activity.

Abstract: An insolubilized antibody suitable for an enzyme immuno assay or radio immuno assay, which has characteristic infrared absorptions at around 1,040 cm.sup.-1, 1,540 cm.sup.-1 and 1,640 cm.sup.-1 and is prepared by chemically binding an antibody to cell wall debris of bacteria or yeasts whose shape is globular or rod-like. There is further disclosed an enzyme immuno assay or radio immuno assay using the insolubilized antibody and a kit containing the insolubilized antibody.