Improvement of dicarboxylic acid production with Methylorubrum extorquens by reduction of product reuptake

ABSTRACT: In the past, two dicarboxylic acid products, namely mesaconic acid and 2‑methylsuccinic acid, were successfully produced by Methylorubrum extorquens AM1 with heterologous thioesterase YciA, but the yield was reduced by product reuptake. In our study we conducted comprehensive research on the uptake mechanism of those dicarboxylic acid products. To identify potential import factors, we performed transcriptome analysis of a strain harboring plasmid pCM160_RBS_yciAHI and an empty vector control strain. Samples were taken and analyzed at different timepoints throughout cultivation. However, we could not identify genes that were clearly upregulated in stationary growth phase compared to early sampling points in the exponential growth phase and which were annotated as potential transporters. When specifically analyzing the time-dependent expression levels of dctA homologs and kgtP (suggested as targets in previous studies) and comparing them with a control strain, we found slightly increased levels only for dctA1. After concluding that the transcriptome analysis was obviously no appropriate approach to identify relevant transport factors, we chose a straightforward mutant selection approach using a cytotoxic dicarboxylic acid.

ORGANISM(S): Methylorubrum extorquens AM1

PROVIDER: GSE199961 | GEO | 2022/04/04

REPOSITORIES: GEO