Page 6 - C. Biotechnology and molecular imaging

[C. Biotechnology and molecular imaging-5]

Antibiotic-free system for phytoene production from

recombinant E. coli

Seung-Hye Lee¹, Seon-Won Kim¹˙*

¹Division of Applied Life Science (BK21 Plus Program), PMBBRC, Gyeongsang National University, Jinju 52828,

Republic of Korea

Phytoene is colorless and absorbs UV-B light from 260 to 320 nm which can be used as a photo-protective material
to prevent urban skin aging. In order to synthesize phytoene in E. coli, the phytoene biosynthesis pathway is

introduced by expression vectors. Expression vectors are maintained by antibiotics. However, when antibiotics are

used in the fermentation process, it causes increase in production costs. Moreover, as the culture progresses for a
long time, the antibiotics are decomposing and the plasmid disappears, leading to a decrease in production. In this
study, for the improved production of phytoene, we applied an antibiotic-free expression system. The system is

based on the isoprenoid pathway such as the MEP pathway and the MVA pathway. These pathways are required
for the production of IPP and DMAPP which are essential metabolites for microbial growth. The genes consisting

of the pathways are used instead of the antibiotic marker gene applying selection pressure to maintain the plasmids.
As a result, it is possible to maintain the plasmid without antibiotics and obtain improved production of phytoene.

This work was supported by the grant from the Next-Generation BioGreen 21 Program (SSAC grant#: PJ01326501),
RDA, Korea.