caa a22 4500 606212906 CHVBK 20210128101045.0 cr unu---uuuuu 210128e20150801xx s 000 0 eng 10.1007/s10295-015-1642-5 doi (NATIONALLICENCE)springer-10.1007/s10295-015-1642-5 Efficient production of indigoidine in Escherichia coli [Elektronische Daten] [Fuchao Xu, David Gage, Jixun Zhan] Indigoidine is a bacterial natural product with antioxidant and antimicrobial activities. Its bright blue color resembles the industrial dye indigo, thus representing a new natural blue dye that may find uses in industry. In our previous study, an indigoidine synthetase Sc-IndC and an associated helper protein Sc-IndB were identified from Streptomyces chromofuscus ATCC 49982 and successfully expressed in Escherichia coli BAP1 to produce the blue pigment at 3.93g/l. To further improve the production of indigoidine, in this work, the direct biosynthetic precursor l-glutamine was fed into the fermentation broth of the engineered E. coli strain harboring Sc-IndC and Sc-IndB. The highest titer of indigoidine reached 8.81±0.21g/l at 1.46g/ll-glutamine. Given the relatively high price of l-glutamine, a metabolic engineering technique was used to directly enhance the in situ supply of this precursor. A glutamine synthetase gene (glnA) was amplified from E. coli and co-expressed with Sc-indC and Sc-indB in E. coli BAP1, leading to the production of indigoidine at 5.75±0.09g/l. Because a nitrogen source is required for amino acid biosynthesis, we then tested the effect of different nitrogen-containing salts on the supply of l-glutamine and subsequent indigoidine production. Among the four tested salts including (NH4)2SO4, NH4Cl, (NH4)2HPO4 and KNO3, (NH4)2HPO4 showed the best effect on improving the titer of indigoidine. Different concentrations of (NH4)2HPO4 were added to the fermentation broths of E. coli BAP1/Sc-IndC+Sc-IndB+GlnA, and the titer reached the highest (7.08±0.11g/l) at 2.5mM (NH4)2HPO4. This work provides two efficient methods for the production of this promising blue pigment in E. coli. Society for Industrial Microbiology and Biotechnology, 2015 Indigoidine nationallicence Glutamine synthetase nationallicence Metabolic engineering nationallicence Escherichia coli nationallicence Streptomyces chromofuscus nationallicence Substrate feeding nationallicence Xu Fuchao Department of Biological Engineering, Utah State University, 4105 Old Main Hill, 84322-4105, Logan, UT, USA aut Gage David Department of Biological Engineering, Utah State University, 4105 Old Main Hill, 84322-4105, Logan, UT, USA aut Zhan Jixun Department of Biological Engineering, Utah State University, 4105 Old Main Hill, 84322-4105, Logan, UT, USA aut Journal of Industrial Microbiology & Biotechnology Springer Berlin Heidelberg 42/8(2015-08-01), 1149-1155 1367-5435 42:8<1149 2015 42 10295 https://doi.org/10.1007/s10295-015-1642-5 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10295-015-1642-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Xu Fuchao Department of Biological Engineering, Utah State University, 4105 Old Main Hill, 84322-4105, Logan, UT, USA aut NATIONALLICENCE 700 1- Gage David Department of Biological Engineering, Utah State University, 4105 Old Main Hill, 84322-4105, Logan, UT, USA aut NATIONALLICENCE 700 1- Zhan Jixun Department of Biological Engineering, Utah State University, 4105 Old Main Hill, 84322-4105, Logan, UT, USA aut NATIONALLICENCE 773 0- Journal of Industrial Microbiology & Biotechnology Springer Berlin Heidelberg 42/8(2015-08-01), 1149-1155 1367-5435 42:8<1149 2015 42 10295