Using Omics Techniques to Analyze the Effects of Gene Mutations and Culture Conditions on the Synthesis of β-Carotene in Pantoea dispersa

Abstract

β-carotene possesses antioxidant properties and holds significant research value. In our study, we have successfully identified a strain of Pantoea dispersa MSC14 which has the capability to produce β-carotene. By incorporating corn steep liquor powder into culture medium and employing mutagenesis breeding techniques, we have successfully increased the production of β-carotene in the MSC14 strain by 13.97% and 29.22%, respectively. To gain further insights, we conducted genomic and transcriptomics analyses. These analyses revealed a significant mutation in the gndA (6-phosphogluconate dehydrogenase) gene of the mutant strain 14P9, resulting in a 33.74% decrease in 6-phosphogluconate dehydrogenase activity. Using transcriptomics analysis, we investigated the impact of this mutation on β-carotene production and explored the interconnectedness between carbon metabolism, fatty acid metabolism, amino acid metabolism, and β-carotene synthesis. The up-regulation of the trxC (Thioredoxin-2) gene, as observed in both transcriptomics results, prompted us to construct strains that overexpress trxC. This manipulation resulted in a notable 15.89% increase in β-carotene production, highlighting the significant impact of of the trxC gene on the β-carotene content of Pantoea dispersa. In conclusion, our study has successfully identified Pantoea dispersa MSC14 as a proficient producer of β-carotene. Furthermore, we have uncovered two genes implicated in the biosynthesis of β-carotene. These findings enhance our understanding of β-carotene synthesis and provide valuable guidance for carotenoid biosynthesis.