[Soil microflora over the closed Donbas mines].

Area of Science:

• Environmental Science
• Microbiology
• Geochemistry

Context:

• Investigating soil gas composition and microflora in diverse soil horizons (up to 30 cm depth) above abandoned Donbas coal mines.
• Identifying zones with significant methane leakages, leading to the formation of explosive and flammable gas mixtures.
• Quantifying methane concentrations ranging from trace amounts to 34% in soil gas.

Purpose:

• To analyze the composition of soil air and microflora in relation to methane leakages from closed coal mines.
• To understand the impact of methane on oxygen and carbon dioxide levels in soil atmospheres.
• To characterize the microbial communities, particularly methanotrophic bacteria, present in these gas-affected soils.

Summary:

• Soil air analysis revealed intensive methane leakages in some areas above closed Donbas coal mines, creating potentially explosive conditions.
• Reduced oxygen (3-4%) and elevated carbon dioxide (up to 5%) concentrations indicate active microbiological processes in methane-rich soils.
• Methanotrophic bacteria were widespread (up to 10^6 cells/g), playing a key role in the biogenic cycling of methane within these technogenic ecosystems.
• Diverse microorganisms were identified, coexisting with methanotrophic bacteria in this specialized environment.

Impact:

• Highlights the environmental risks associated with abandoned coal mines, specifically the formation of hazardous gas mixtures.
• Demonstrates the adaptability and prevalence of methanotrophic bacteria in extreme methane-rich environments.
• Provides insights into the microbial ecology of technogenic soils and their role in biogeochemical cycles.