Genomic characterization of phosphate-solubilizing Klebsiella variicola strain PSEG-1 from earthworm gut.

Phosphorus (P) is an essential macronutrient for plant growth that plays a critical role in photosynthesis, DNA synthesis, and energy transfer. Phosphorus deficiency is a major limitation to plant growth and agricultural productivity globally. This deficiency arises from a combination of soil composition, agricultural practices, plant physiological responses, and environmental factors. Understanding these factors is crucial for developing strategies to mitigate phosphorus deficiency and improve crop yields. The isolation, characterization, and application of potent indigenous bacteria capable of phosphorus solubilization are of significant importance in acidic soils to overcome the challenges posed by phosphorus fixation. In this study, we report the genome sequencing of Klebsiella variicola strain PSEG-1, isolated from the gut of the earthworm Aporrectodea sp. that exhibits notable phosphorus solubilization ability. Genomic analysis reveals that the PSEG-1 genome comprises a single chromosome of 5.69 Mb, with a GC content of 57.07%, and encodes 5,596 protein-coding sequences, 4 rRNA genes, and 80 tRNA genes. Functional annotation of the genome identified 19 distinct categories of protein-coding genes, with a notable representation of genes involved in amino acid transport and metabolism, carbohydrate transport and metabolism, and transcriptional regulation. Notably, the genetic repertoire of PSEG-1 comprises 37 genes implicated in organic acid metabolism, 5 genes associated with phosphatase activity, and 2 genes directly involved in phosphate metabolism. These findings highlight the potential of K. variicola PSEG-1 to enhance phosphorus availability in nutrient-deficient environments.