SANITARY AND HYGIENIC STATE OF SOIL BY MICROBIOLOGICAL INDICATORS: DATA FROM METAGENOMIC AND CULTURAL ANALYSES

Abstract

Introduction. Under conditions of increased technogenic load and enterprise relocation, monitoring the sanitary and hygienic state of soils is critical for the region’s environmental safety. Current regulatory gaps and the limitations of classical analytical methods necessitate the implementation of modern molecular genetic approaches for an objective assessment of territories. Objective. The work aims to evaluate the sanitary and hygienic state of technogenically modified soils in Transcarpathia using traditional cultural and modern metagenomic methods. Materials and Methods. The study focused on soil samples from the zones influenced by a timber chemical plant and railway transport, collected in June 2025. The methodology included classical plating on selective media and metagenomic sequencing of 16S rRNA gene regions, followed by functional prediction using the FAPROTAX database. Results. It was established that the total microbial count in technogenic zones significantly exceeds the control, although no direct signs of recent fecal contamination were found (coli-index <1000 CFU/kg). Metagenomic analysis recorded a twofold higher content of nitrifiers in technogenic soils, indicating intensive self-purification processes, and identified functional groups of potential pathogens (Burkholderiales, Aquabacterium, C. perfringens) that indicate potential epidemic hazards and long-term contamination. Conclusions. The combination of classical and metagenomic methods ensures high accuracy in hygienic assessment, revealing hidden changes in the microbial community structure of technogenic areas. The findings emphasize the need to modernize the monitoring system and include genetic indicators in the protocols for sanitary-epidemiological soil control.