# Isolation and Mechanistic Characterization of Pediococcus pentosaceus WQ-30 from Kimchi for Efficient In Vitro Purine Nucleoside Degradation Relevant to Hyperuricemia

## TL;DR

A new strain of bacteria, Pediococcus pentosaceus WQ-30, was found to efficiently break down purine nucleosides, which could help reduce uric acid levels in people with hyperuricemia.

## Contribution

The study isolates and characterizes a novel Pediococcus pentosaceus strain with high purine nucleoside degradation efficiency and identifies the key gene rihC responsible for this activity.

## Key findings

- Pediococcus pentosaceus WQ-30 degrades inosine and guanosine with efficiencies of 93.99% and 98.88%, respectively.
- The rihC gene encodes a nucleoside hydrolase with optimal activity at pH 7 and 37°C.

## Abstract

Hyperuricemia (HUA) is a metabolic syndrome caused by elevated levels of uric acid (UA) serum, posing a significant threat to human health. Lactic acid bacteria degrade or adsorb UA precursors such as purine nucleosides and metabolites. By inhibiting intestinal nucleoside absorption, UA synthesis is reduced and HUA alleviated. A total of 60 fermented food samples and 20 soil samples were collected for screening. Strains were selected based on their inosine and guanosine degradation efficiency, and all degradation assays were performed in triplicate (n = 3). We isolated a strain that efficiently degrades inosine and guanosine at rates of 93.99% and 98.88%, respectively. This strain was identified as Pediococcus pentosaceus (P. pentosaceus) via 16S rDNA sequencing and named WQ-30. Whole-genome assembly yielded one chromosome and one plasmid, with 1705 coding sequences. The key gene rihC, encoding a nucleoside hydrolase, was identified through gene functional annotation. Heterologous expression and purification confirmed that RihC was approximately 36 kDa. Recombinant RihC exhibited optimal nucleoside hydrolase activity at pH 7 and 37 °C. This study provides a promising strain for functional food development and a mechanistic basis for the application of P. pentosaceus with purine nucleoside degradation and UA-lowering activities.