초록
<P>Lycopene is an import ant compound with an increasing industrial value. However, there is still no biotechnological process to obtain it. In this study, a semi-continuous system for lycopene extraction from recombinant <I>Escherichia coli BL</I>21 cells is proposed. A two-phase culture mode using organic solvents was found to maximize lycopene production through in situ extraction from cells. Within the reactor, three phases were formed during the process: an aqueous phase containing the recombinant <I>E. coli</I>, an interphase, and an organic phase. Lycopene was extracted from the cells to both the interphase and the organic phase and, consequently, thus enhancing its production. Maximum lycopene production (74.71 ± 3.74 mg L<SUP>−1</SUP>) was obtained for an octane-aqueous culture system using the <I>E. coli</I> BL21LF strain, a process that doubled the level obtained in the control aqueous culture. Study of the interphase by transmission electron microscopy (TEM) showed the proteo-lipidic nature and the high storage capacity of lycopene. Moreover, a cell viability test by flow cytometry (CF) after 24 h of culture indicated that 24 % of the population could be re-used. Therefore, a batch series reactor was designed for semi-continuous lycopene extraction. After five cycles of operation (120 h), lycopene production was similar to that obtained in the control aqueous medium. A final specific lycopene yield of up to 49.70 ± 2.48 mg g<SUP>−1</SUP> was reached at 24 h, which represents to the highest titer to date. In conclusion, the aqueous-organic semi-continuous culture system proposed is the first designed for lycopene extraction, representing an important breakthrough in the development of a competitive biotechnological process for lycopene production and extraction.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1186/s13568-015-0150-3) contains supplementary material, which is available to authorized users.</P>