Enhancing the biosynthesis of 2-keto-L-gulonic acid through multi-strategy metabolic engineering in Pseudomonas putida KT2440.

2-KGA, a precursor for the synthesis of Vitamin C, is currently produced in China utilizing the "two-step fermentation" technique. Nevertheless, this method exhibits many inherent constraints. This study presents a comprehensive metabolic engineering strategy to establish and optimize a one-step 2-KGA fermentation process from D-sorbitol in Pseudomonas putida KT2440.

Identification and Validation of Four Novel Promoters for Gene Engineering with Broad Suitability across Species.

The transcriptional capacities of target genes are strongly influenced by promoters, whereas few studies have focused on the development of robust, high-performance and cross-species promoters for wide application in different bacteria. In this work, four novel promoters (P, P1, P2, and P3) were predicted from and their inconsistency in the -10 and -35 region nucleotide sequences indicated they were different promoters. Their activities were evaluated by using green fluorescent protein () as a reporter in different species of bacteria, including SPU B805, KT2440, PD1222, and , due to their importance in metabolic engineering.

Reconstruction and analysis of carbon metabolic pathway of Ketogulonicigenium vulgare SPU B805 by genome and transcriptome.

Ketogulonicigenium vulgare has been widely used in vitamin C two-step fermentation. Four K. vulgare strains (WSH-001, Y25, Hbe602 and SKV) have been completely genome-sequenced, however, less attention was paid to elucidate the reason for the differences in 2-KGA yield on genetic level.