Search

Microbial communities of wetlands play key roles in the earth's ecology and stability. To elucidate the cold adaptation mechanisms of bacteria in plateau wetlands, we conducted comparative genomic analyses of Pseudomonas sivasensis and closely related lineages. The genome of P. sivasensis W-6, a cold-adapted bacterium isolated from the Napahai plateau wetland, was sequenced and analyzed. The genome length was 6,109,123 bp with a G+C content of 59.5%. Gene prediction yielded 5360 protein-coding sequences, 70 tRNAs, 24 gene islands, and 2 CRISPR sequences. The isolate contained evidence of horizontal gene transfer events during its evolution. Two prophages were predicted and indicated that W-6 was a lysogen. The cold adaptation of the W-6 strain showed psychrophilic rather than psychrotrophic characteristics. Cold-adapted bacterium W-6 can utilize glycogen and trehalose as resources, associated with carbohydrate-active enzymes, and survive in a low-temperature environment. In addition, the cold-adapted mechanisms of the W-6 included membrane fluidity by changing the unsaturated fatty acid profile, the two-component regulatory systems, anti-sense transcription, the role played by rpsU genes in the translation process, etc. The genome-wide analysis of W-6 provided a deeper understanding of cold-adapted strategies of bacteria in environments. We elucidated the adaptive mechanism of the psychrophilic W-6 strain for survival in a cold environment, which provided a basis for further study on host-phage coevolution., (© 2023. Springer Nature Limited.)

Viruses play important roles in ecosystems by interfering with the central metabolic pathways of the host during infection via the expression of auxiliary metabolic genes (AMGs), altering the productivity of ecosystems and thus affecting geochemical cycling. In this study, the genetic diversity of phosphorus metabolism AMGs phoH, phoU and pstS was investigated by phylogenetic analysis, PCoA analysis, and alpha diversity analysis based on metagenomic data. It was found that the majority of the sequences were unique to Napahai plateau wetland. It was shown that the genetic diversity of phoH, phoU and pstS genes was independent of both habitats and host origins. In addition, the metabolic pathway of AMGs associated with the phosphorus cycling was identified based on metagenomic data. When phosphorus is deficient, virus utilizes AMGs to affect the metabolic pathway, contributing to higher phosphorus levels in the host and facilitating virus survival, replication, and propagation in the host cell., (© 2023. The Author(s).)