Gas-producing bacteria were isolated from natural media: soil and compost extracts. The properties of the obtained microorganisms cultures as destructors of organic substances were studied. Studied bacteria were cultivated in experimental semi-synthetic media with saw dust and carboxymethyl cellulose. A growth at different pH values, a dynamics of growth, an amount of utilizated sugar, a volume of released gas during cultivation were studied. Most intensive growth of gas-producing cultures has been observed in a medium with CMC and the ability to gas producing was more manifested in the bacterial culture isolaited from the compost.