The aim of the study was to evaluate the biotechnological potential of thermophilic mi-croorganisms isolated from chernozem soil during composting of poultry manure. The ef-ficiency of the strains was determined by their effect on organic matter degradation, humi-fication intensity, and nitrogen accumulation. The correlation between the quality indica-tors of composting process was assessed with the gross values, taking into account the proportion of compost fractions. The strains were identified as: Aeribacillus pallidus KCTC 3564T (cellulolytic), Neobacillus sedimentimangrovi FJAT-2464T, Aeribacillus composti N.8T, Caldifermentibacillus hisashii N-11T (nitrogen fixers) and Acinetobacter pittii CIP 70.29T, Pseudomonas plecoglossicida NBRC 103162T (nitrifies). It was found that all the bacteria increase the proportion of small fractions by 19.0-19.9%. The gross content of humic acids increases under the influence of nitrifiers (15.5%) and nitrogen fixers (5.5%). The total nitrogen content increases under cellulolytics (13.8%) and nitrogen fixers (20.2%). The smallest fraction (≤0.25 mm) in nitrogen fixers and nitrifies variants has the greatest bioreclamation properties, by 16.4% and 12.9%. Targeted microbial strains pro-vide the direction of the transformation processes while biocomposting. It can also be con-cluded that assessing the quality of composting based on the fraction distribution can be a promising element of the biofermentation process monitoring.

The aim of the study was to evaluate the biotechnological potential of thermophilic microorganisms isolated from chernozem soil during composting of poultry manure. The efficiency of the strains was determined by their effect on organic matter degradation, humification intensity, and nitrogen accumulation. The correlation between the quality indicators of the composting process was assessed with the gross values, taking into account the proportion of compost fractions. The strains were identified as: Aeribacillus pallidus KCTC 3564^T (cellulolytic), Neobacillus sedimentimangrovi FJAT-2464^T, Aeribacillus composti N.8^T, Caldifermentibacillus hisashii N-11^T (nitrogen fixers), Acinetobacter pittii CIP 70.29^T, and Pseudomonas plecoglossicida NBRC 103162^T (nitrifies). It was found that all the bacteria increase the proportion of small fractions by 19.0–19.9%. The gross content of humic acids increases under the influence of nitrifiers (15.5%) and nitrogen fixers (5.5%). The total nitrogen content increases under cellulolytics (13.8%) and nitrogen fixers (20.2%). The smallest fraction (≤0.25 mm) in nitrogen fixers and nitrifying variants has the greatest bioreclamation properties, by 16.4% (p < 0.001) and 12.9% (p < 0.001). Targeted microbial strains provide the direction of the transformation processes during biocomposting. It can also be concluded that assessing the quality of composting based on the fraction distribution can be a promising element of the biofermentation process monitoring.