Original scientific paper

https://doi.org/https://doi.org/10.5513/MOOJ3392

Microbial structure, diversity, and function in saline soils of Belozem, Bulgaria: a metagenomic and enzymatic activity assessment

Georgina Asare orcid.org/0009-0005-3286-561X ; Department of Microbiology and Environmental Biotechnology, Faculty of Plant Protection and Agroecology, Agricultural University-Plovdiv, Bulgaria
Vanya Popova ; Department of Microbiology and Environmental Biotechnology, Faculty of Plant Protection and Agroecology, Agricultural University-Plovdiv, Bulgaria
Mariana Petkova ; Department of Microbiology and Environmental Biotechnology, Faculty of Plant Protection and Agroecology, Agricultural University-Plovdiv, Bulgaria
Stefan Shilev orcid.org/0000-0002-1172-881X ; Department of Microbiology and Environmental Biotechnology, Faculty of Plant Protection and Agroecology, Agricultural University-Plovdiv, Bulgaria
Orhan Dengiz ; Department of Soil Science and Plant Nutrition, Faculty of Agriculture, Ondokuz Mayıs University, Samsun, Turkey

Abstract

Saline soils represent a major challenge to agricultural productivity, particularly in regions like Belozem, Bulgaria, where salinisation is both naturally occurring and anthropogenically induced. This study investigated the microbial status of strongly saline soils through a combination of conventional microbiological methods and metagenomic sequencing. Soil respiration, substrate induced respiration, colonyforming units, and enzymatic activities (β-glucosidase and dehydrogenase) were assessed, alongside high-throughput 16S rRNA gene sequencing. The results
indicated that increased soil salinity and gravimetric water content negatively affected microbial respiration and diversity. The microbial community was dominated by halotolerant taxa including Actinobacteriota, Proteobacteria, and Firmicutes. Soil respiration was significantly correlated with moisture, and substrate induced respiration values revealed high microbial dormancy under saline stress. Enzyme assays indicated suppressed metabolic activity in high-salt environments, particularly in soils with the lowest pH and highest conductivity values. Metagenomic analysis revealed variations in alpha and beta diversity across the three soil types, reflecting salinity-induced shifts in microbial community structure and function. These findings highlight the ecological consequences of salinity on soil microbial dynamics and suggest that metagenomic approaches can offer valuable insights for managing saline-affected ecosystems.

Keywords

Soil bacteriome; Soil respiration; Enzymes; Halotolerant bacteria; 16S rRNA sequencing

Hrčak ID:

348320

URI

https://hrcak.srce.hr/348320

Publication date:

27.6.2026.

Article data in other languages: croatian

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