University of Guilan Caspian Journal of Environmental Sciences 1735-3033 21 3 2023 07 01 Screening and evaluation of potential microbial bio-activators used in sewage sludge composting 575 583 6936 10.22124/cjes.2023.6936 EN Makpal Bostubayeva NCJSC “S.Seifullin Kazakh AgroTechnical Research University”, Zhenis Avenue 62, 010010 Astana City, Republic of Kazakhstan Elmira Baimbetova NCJSC “S.Seifullin Kazakh AgroTechnical Research University”, Zhenis Avenue 62, 010010 Astana City, Republic of Kazakhstan Meruyert Makenova NCJSC “S.Seifullin Kazakh AgroTechnical Research University”, Zhenis Avenue 62, 010010 Astana City, Republic of Kazakhstan Nazymgul Shumenova NCJSC “S.Seifullin Kazakh AgroTechnical Research University”, Zhenis Avenue 62, 010010 Astana City, Republic of Kazakhstan Roza Sarmanova NCJSC “S.Seifullin Kazakh AgroTechnical Research University”, Zhenis Avenue 62, 010010 Astana City, Republic of Kazakhstan Ainash Nauanova NCJSC “S.Seifullin Kazakh AgroTechnical Research University”, Zhenis Avenue 62, 010010 Astana City, Republic of Kazakhstan Journal Article 2023 07 27 Forty pure microbial cultures have been isolated from sewage sludge to develop biopreparations using the microbiological screening method. Among all studied microorganisms sixteen strains of different taxonomic groups (2 strains of each <em>Bacillus</em> and <em>Streptomyces</em>, 7 strains of <em>Pseudomonas</em>, and 1 strain of each of the following <em>Acinetobacter</em>, <em>Rhizobium</em>, <em>Pseudarthrobacter</em>, <em>Sphingomonas</em>, and <em>Rothia</em>) were selected providing the best cellulose-degrading ability, as well as having good growth and quick biomass accumulation on various substrates. The isolates were additionally tested for the ability to consume organic and mineral nitrogen species, and to encourage seedlings’ growth. Moreover, we have evaluated the nitrogenase activity for some strains. As a result, the following strains of <em>Bacillus megaterium </em>№ 10,<em> Rhizobium pusense </em>№ 25,<em> Sphingomonas paucimobilis </em>№ 49,<em> Pseudomonas fluorescens </em>№ 83,<em> Streptomyces albidoflavus </em>№ 81,<em> Streptomyces graminearus </em>№ 61<em> </em>demonstrated the potential to be used as bio-activator for sewage sludge composting and as multifunctional biologics in crop production. https://cjes.guilan.ac.ir/article_6936_e89c2203aff22d04187281512e11f9ee.pdf