The present invention provides a mixed bacterial culture, designated as the culture Atz Mix 1, which degrades atrazine at various temperatures (10° C. to 30° C.) in a wide range of atrazine concentrations (several ppb to ten thousand ppm), without formation of toxic metabolites. Atz Mix 1 is a stable mixed culture and includes catabolic genes trzN, atzB, atzC coding the enzymes for the degradation of atrazine to cyanuric acid, and the gene trzD coding the enzymes for subsequent opening of s-triazine ring. The invention further includes a microbiological method of degrading atrazine and other s-triazine compounds for remediation of atrazine-contaminated soils, even those rich in nitrogen, as well as for accelerating the process of atrazine mineralization in waste waters containing high concentrations of s-triazine compounds.