Complete genome sequence and comparative genome analysis of the Paenibacillus mucilaginosus K02

Paenibacillus mucilaginosus (P. mucilaginosus) K02 is implicated in mineral weathering. However, relevant molecular mechanisms remain obscure. The study aims to uncover the bacterium's physiological processes using genomic approaches.

Genomic DNA from P. mucilaginosus K02 was sequenced using high-throughput Solexa sequencing technology and then conducted for Clusters of Orthologous Group (COG) annotation. Thereafter, genome sequences of K02 were compared with two strains, 3016 and KNP414. Mummer was applied for collinearity analysis of three P. mucilaginosus genomes. BLAST was used to identify pan and core genes in these strains. Finally, a phylogenetic tree was constructed using the maximum likelihood method by TreeBeST. Complete genome sequence of P. mucilaginosus K02 indicated the strain comprises one circular chromosome with 8,819,200 bases containing 58.3% GC content and 84.75% coding regions. A total of 7299 predicted ORFs were identified in the genome, among them, several genes were related to carbonic anhydrase (CA), and exopolysaccharide biosynthesis and secretion. Moreover, proteins of the predicted genes were annotated in COG categories such as "Carbohydrate transport and metabolism" and "Inorganic ion transport and metabolism." In comparison with KNP414 and 3016, K02 exhibited chromosomal recombination or transposition. A total of 6662 core genes were identified among three P. mucilaginosus strains. The phylogenomic study indicated that P. mucilaginosus K02 was clustered with P. mucilaginosus strains 3016 and KNP414.

In P. mucilaginosus K02, genes related to CA and exopolysaccharide biosynthesis and secretion, and that involved in metabolism-related processes might play significant roles in mineral weathering.