초록
<P>Ethylene is a volatile alkene which is used in large commercial scale as a precursor in plastic industry, and is currently derived from petroleum refinement. As an alternative production strategy, photoautotrophic cyanobacteria <I>Synechocystis</I> sp. PCC 6803 and <I>Synechococcus elongatus</I> PCC 7942 have been previously evaluated as potential biotechnological hosts for producing ethylene directly from CO<SUB>2</SUB>, by the over-expression of ethylene forming enzyme (efe) from <I>Pseudomonas syringae</I>. This work addresses various open questions related to the use of <I>Synechococcus</I> as the engineering target, and demonstrates long-term ethylene production at rates reaching 140 µL L<SUP>−1</SUP> h<SUP>−1</SUP> OD<SUB>750</SUB><SUP>−1</SUP> without loss of host vitality or capacity to produce ethylene. The results imply that the genetic instability observed earlier may be associated with the expression strategies, rather than efe over-expression, ethylene toxicity or the depletion of 2-oxoglutarate—derived cellular precursors in <I>Synechococcus</I>. In context with literature, this study underlines the critical differences in expression system design in the alternative hosts, and confirms <I>Synechococcus</I> as a suitable parallel host for further engineering.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (10.1007/s11274-019-2652-7) contains supplementary material, which is available to authorized users.</P>