Screening of uric acid-degrading lactic acid bacteria consortium and strain combination for enhancing degradation

Abstract:

[Background] Hyperuricemia is caused by a significant increase the content of uric acid in the blood, and using probiotic lactic acid bacteria to relieve hyperuricemia has attracted more and more attention. [Objective] To obtain the lactic acid bacteria consortium and pure culture strains with the ability to degrade uric acid. [Methods] We used the MRS medium with uric acid as the substrate to isolate the consortium of lactic acid bacteria degrading uric acid from kimchi. Further, we determined the uric acid degradation ability of the consortium by high performance liquid chromatography. [Results] A consortium of lactic acid bacteria was obtained. After being cultured at 37 °C and pH 6.20 for 72 h, the consortium showed the degradation rate of 12.08% for uric acid. Moreover, after optimization of degradation conditions, the degradation rate was increased to 17.19% after inoculation 72 h under the conditions of beef extract as the single nitrogen source, initial pH 5.00, and 35 °C, and the degradation rate increased by 42.3% compared with that before optimization. Two strains UA-1 and UA-2 with uric acid degradation ability were isolated from the consortium, and their uric acid degradation rates were 10.85% and 8.65%, respectively. The two strains were identified as Lactobacillus buchneri based on morphological characteristics and 16S rRNA sequence. The combination of UA-1 and UA-2 at a ratio of 2:1 showed the uric acid degradation rate of 20.2%, which was 67.22% higher than that of the consortium. [Conclusion] This study proved that the combination of lactic acid bacteria had better degradation effect on uric acid than single strains, which provided data support for the subsequent application use of lactic acid bacteria consortium.