Effect and potential mechanism of nitrite reductase B on nitrite degradation by Limosilactobacillus fermentum RC4

• DOI: 10.1016/j.crfs.2024.100749
• Publication Date: 2024-04-24T01:55:46Z
• Authors: Qing Fan; Chaoran Xia; Xiaoqun Zeng; Zhen Wu; Yuxing Guo; Qiwei Du; Maolin Tu; Xinanbei Liu; Daodong Pan
• Keywords: Lactobacillus fermentum

Nitrite has the potential risk of hypoxic poisoning or cancer in pickled food. In our previous study, Limosilactobacillus fermentum (L. fermentum) RC4 is effective nitrite degradation by producing reductase B (NirB). To investigate detailed mechanism from genome, response, and regulation NirB, whole-genome sequence L. was analyzed, fermentum-EGFP-nirB with enhanced green fluorescent protein (EGFP) labeled large subunit nirB, recombined fermentum-NirB overexpression NirB strain conducted. The key genes within dominant metabolism pathways may be involved stress tolerance to regulate degrading process. fluorescence density EGFP indicated that activity a threshold peaked under 300 mg/L concentration. overexpressed boosted enzyme 39.6% rate 10.5%, when fermented for 40 h, compared control group. RNA-seq detected 248 differential mainly enriched carbohydrate, amino acid, energy metabolism. ackA gene pyruvate mtnN cysteine were up-regulated. regulates these produce acid improve resistance accelerate degradation.