Abstract: Anti-microbial compositions are described which contain iodide and thiocyanate anions, an oxidoreductase enzyme, namely glucose oxidase, and its corresponding oxidisable substrate, D-glucose. Such compositions may advantageously further comprise a peroxidase such as lactoperoxidase. The compositions have excellent anti-microbial properties effective against bacteria yeasts and moulds. The compositions may be provided in concentrated substantially non-reacting forms such as dry powders and non-aqueous solutions which may be diluted to provide compositions with broad spectrum anti-microbial activity. Compositions may be used as preservatives or as active agents providing potent anti-microbial activity of use in oral hygiene, deodorant and anti-dandruff products.

Abstract: Novel solid antibacterial compositions suitable for use in an oil or gas well comprise at least 50% by weight of a solid antibacterial nitroalkanol compound active against sulphate-reducing bacteria and a carrier, the composition having a density of at least 1.2 g/cm.sup.3 and being adapted to dissolve, disintegrate or disperse in water but not in oil. A preferred antimicrobial compound is 2-bromo-2-nitropropane-1,3-diol. The antibacterial compositions are introduced into the aqueous layer in the sump at the bottom of the collecting system of the oil or gas well. This inhibits corrosion in the metal work of the oil or gas well, for example the pipe lines of the collecting system.