Genomic analysis of Rhodopirellula sp. P2 reveals its role in fucoidan degradation.

Fucoidan, the main polysaccharide in various species of brown seaweed, has a high annual production. It is an important source of marine organic carbon and exhibits diverse biological activities and significant application potential. Rhodopirellula sp. P2, a novel marine bacterium of the phylum Planctomycetota, was isolated from intertidal algae samples collected from the Weihai coast, the Yellow Sea, China. The strain P2 is a Gram-negative, aerobic, and pear-shaped bacterium. Here, we report the complete genome sequence of Rhodopirellula sp. P2. The genome of strain P2 consists of a single circular chromosome with 7,291,416 bp and a GC content of 57.38 %, including 5462 protein-coding genes, 2 rRNA genes, and 48 tRNA genes. Genomic analysis revealed that strain P2 possessed 173 CAZymes and 106 sulfatases, indicating that strain P2 has the potential ability to utilize multiple polysaccharides, especially hydrolyze fucoidan to fucose. The genome of strain P2 also encodes a gene cluster related to bacterial microcompartment, suggesting the ability of strain P2 to metabolize fucose. These results enhance the understanding of the diversity and ecological functions of Planctomycetota, and also facilitate the exploitation of Planctomycetota and enzyme resources to utilize fucoidan. This study provides genetic insights into fucoidan catabolism by Planctomycetota, expanding our understanding of fucoidan-degrading microbial groups.