V. KRUGLOV, T.O. LISINA All-Russian Research Institute of Agricultural Microbiology, Russian Academy of Agricultural Sciences, 3, sh. <...> Its effectiveness depends on many factors (i.e. the type and strain of microorganism, the physical and chemical properties of the soil, plant cover, climate and so on), which are not well understood, leading to a high variability of the results of application of microbial preparations. <...> In this article, there is reported the first investigation of survival and sporulation dynamics of Bacillus megaterium 501rif introduced into sodpodzolic soil, depending on the temperature of the soil, organic matter content and herbicide prometryn, the 2-methylthio-4,6-bis (iso-propylamino)-sim-triazine, application. <...> After the third day after inoculation the titer of bacteria in the soil increased almost 10 times and remained at that level until the end of the experiment (32 days). <...> B. megaterium 501rif throughout the experiment was mainly in the form of a physiologically active cells and fits well into the soil microbiom. <...> Under these conditions an additional incorporation into the soil of the organic matter, such as cereal straw and corn flour, leads to 10-100-fold increase of the amount of B. megaterium 501rif. <...> At 37 °С the total number of B. megaterium 501rif reduced several times, and stabilized at this level until the end of the experiment. <...> The temperature below the minimum for physiological reproduction of B. megaterium (4 °С) inhibits spore formation and leads to a rapid loss of physiologically active bacterial cells introduced into the soil. <...> The total number of bacteria decreases 1000 times within a month. <...> These data lead to the conclusion that the «low-temperature shock» reduces the competitiveness of B. megaterium to the indigenous microflora and its resistance to bactericidal metabolic products of soil biome. <...> It is shown that at the optimum temperature (20 °С) of soil the B. megaterium inoculation and the use of additional organic matter such as straw accelerate the decomposition of herbicide prometryn, can potentially be used in a biotechnology of remediation of the soil, contaminated by herbicide. <...> Bacterial preparations are used in agriculture to stimulate plant growth and development, to protect plant against phytopathogens and pests, and as well for cleaning the soil from xenobiotics (1-4). <...> Aerobic sporulating bacteria of the genus Bacillus, i.e. B. thuringiensis (5, 6), B. subtilis (7), B. megaterium (8-10) are widely applied as they are well manufacturable, long <...>