Impact of Environmental Disruption on Microbial and Enzymatic Dynamics of Chornozem Soils

Severe anthropogenic disturbances can induce long-term ecological shifts, particularly in sensitive biological systems such as soil microbial communities. In this study, we investigated the impact of intensive environmental disruption on microbial fermentation processes and associated enzymatic activity in black soils (chornozem) of the Kharkiv region (Ukraine). Microorganisms were determined using tenfold dilution techniques and selective media. To assess fermentation-related activity, we quantified key soil enzymes. Results revealed a two-to-three-order-magnitude decline in total microbial abundance, especially among agronomically important fermentation-related groups such as phosphate-mobilizing, nitrogen-fixing, and cellulosolytic microorganisms. Enzymatic activity showed a parallel collapse: invertase, urease, and protease, critical to organic matter fermentation and nitrogen transformation, decreased significantly, indicating stalled biochemical turnover. Phosphatase and dehydrogenase activities dropped, reflecting impaired phosphorus release and microbial respiration. Meanwhile, oxidative enzymes such as catalase, polyphenol oxidase, and peroxidase showed altered activity, suggesting oxidative stress and disrupted humus formation pathways. The degradation of microbial fermentation potential and enzymatic function in disturbed chornozem soils highlights the urgent need for biological restoration. Our findings provide a biochemical basis for developing remediation strategies focused on reactivating microbial fermentation and enzymatic networks critical for ecosystem recovery and sustainable soil management.