Phylogenetic and metabolic diversity of environmental Pseudomonas spp. isolated from the Białowieża National Park

The genus Pseudomonas comprises metabolically versatile bacteria widely distributed across various ecosystems. Their physiological plasticity enables adaptation to diverse ecological niches and contributes to their important role in nutrient cycling and ecosystem functioning. However, the diversity of environmental Pseudomonas spp. inhabiting natural ecosystems with minimal anthropogenic impact remains insufficiently characterized. The Białowieża National Park, one of the last preserved primeval forests in Europe, provides a unique opportunity to investigate naturally occurring bacterial diversity under minimal anthropogenic influence.

The aim of this study was to characterize the phylogenetic relationships and metabolic diversity of environmental Pseudomonas isolates from forest soil samples collected in the Białowieża National Park. Phylogenetic identification was performed using the 16S rRNA and gyrB genes sequencing, followed by phylogenetic tree construction. Metabolic diversity was assessed using the API 20 NE biochemical identification system, enabling comparative analysis of substrate utilization profiles among the investigated isolates. Phylogenetic analysis demonstrated that the isolates clustered into three phylogenetic groups (P. fluorescens, P. koreensis, P. putida) within the genus Pseudomonas, reflecting considerable genetic diversity. Biochemical profiling revealed substantial variation in metabolic capabilities, particularly in the utilization of selected carbohydrates, organic acids, and other carbon sources. Although some isolates exhibited similar phylogenetic affiliations, differences in their metabolic fingerprints indicated functional diversification, suggesting adaptation to distinct ecological microhabitats within the same forest ecosystem.

The combined application of molecular phylogenetic analysis and biochemical profiling provides complementary insights into the diversity of environmental Pseudomonas spp. These findings highlight the ecological complexity of bacterial communities inhabiting natural forest soils and emphasize that phylogenetic relatedness alone does not fully reflect functional diversity. Understanding both genetic and metabolic variability among environmental bacteria contributes to a more comprehensive view of microbial biodiversity and the ecological mechanisms underlying adaptation in natural ecosystems.