Production of 5-aminolevulinic acid from glutamate by overexpressing HemA1 and pgr7 from Arabidopsis thaliana in Escherichia coli

In this study, we introduced theHemA1 andpgr7 genes from the higher plantArabidopsis thaliana into recombinantEscherichia coli to overproduce extracellular 5-aminolevulinic acid via the C5 pathway. In theE. coli BL21 (DE3) strain background, the ALA concentration of the strain expressing bothHemA1 andpgr7 was the highest and reached 3080.62  mg/L. Among the 7 tested hosts, ALA production was the highest inE. coli Transetta (DE3). InE. coli Transetta GTR/GBP, the expression levels ofzwf, gnd, pgl andRhtA were upregulated. Glutamate induced the expression ofthe GltJ, GltK, GltL andGltS genes that are in involved in glutamate uptake. The recombinantE. coli Transetta GTR/GBP was able to produce 7642  mg/L ALA in modified minimal medium supplemented with 10 g/L glutamate and 15 g/L glucose after 48 h of fermentation at 22 °C. The results provide persuading evidence for the efficient production of ALA from glucose and glutamate inE. coli expressingA. thaliana HemA1 andpgr7. Further optimization of the fermentation process should be done to improve the ALA production to an industrially relevant level.
Source: World Journal of Microbiology and Biotechnology - Category: Microbiology Source Type: research