5-Aminolevulinic acid (ALA) is a non-protein amino acid with a significant potential for cancer treatment and plant stress resistance. Microbial fermentation has gradually replaced the traditional chemical-based method for ALA production, thus increasing the need for high-ALA-producing strains. In this study, we engineered the glutamate producing strain, Corynebacterium glutamicum S9114, for ALA production. To efficiently convert l-glutamate to ALA, hemA and hemL from Salmonella typhimurium and Escherichia coli were tandemly overexpressed. In addition, ncgl1221 encoding a glutamate transporter was deleted to block glutamate secretion and thus improve ALA production. Furthermore, the intrinsic ribosome-binding site (RBS) of hemB was replaced by a relatively weak RBS to reduce the conversion of ALA to porphyrin. Transcriptional and fermentation data confirmed that inactivation of lysE and putP reduced the conversion of glutamate to arginine and proline, which also contribute to ALA production. The final SA14 strain produced 895 mg/L concentration of ALA after 72 h incubation in a shake flask. This amount was 58-fold higher than that obtained by the parent strain C. glutamicum S9114. The results demonstrate the potential of C. glutamicum S9114 for efficient ALA production and provide new targets for the development of ALA-producing strains.
3 Biotech – Springer Journals
Published: May 8, 2018
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera