Biosynthesis of 1-Alkenes in Engineered Microorganisms
Various 1-alkenes, including 1-nonadecene and 1-octadecene, are synthesized by the engineered microorganisms and methods of the invention. In certain embodiments, the microorganisms comprise recombinant 1-alkene synthases. The engineered microorganisms may be photosynthetic microorganisms such as cyanobacteria.
1 . A method for the biosynthetic production of 1-alkenes, comprising:
culturing an engineered microorganism in a culture medium, wherein said engineered microorganism comprises a recombinant 1-alkene synthase, wherein said 1-alkene synthase is at least 95% identical to SEQ ID NO: 2, and wherein the amount of said 1-alkenes produced by said engineered microorganism is greater than the amount that would be produced by an otherwise identical microorganism, cultured under identical conditions, but lacking said recombinant 1-alkene synthase.
2 . The method of claim 1 , wherein said recombinant 1-alkene synthase is an endogenous 1-alkene synthase expressed, at least in part, from a promoter other than its native promoter.
3 . The method of claim 1 , wherein said recombinant 1-alkene synthase is a heterologous 1-alkene synthase.
4 . The method of claim 1 , wherein said recombinant 1-alkene synthase is expressed from a heterologous promoter.
5 . The method of claim 4 , wherein said 1-alkene synthase is endogenous to said microorganism.
6 . The method of claim 1 , wherein said engineered microorganism is a photosynthetic microorganism, and wherein exposing said engineered microorganism to light and carbon dioxide results in the production of alkenes by said microorganism.
7 . The method of claim 6 , wherein said engineered microorganism is a cyanobacterium.
8 . The method of claim 1 or 6 , wherein said 1-alkenes are selected from the group consisting of 1-nonadecene and 1-octadecene.
9 . The method of claim 1 or 6 , further comprising isolating said 1-alkenes from said cyanobacterium or said culture medium.
10 . A method for the biosynthetic production of an olefin, comprising
(1) culturing a cyanobacterium in a culture medium, wherein said cyanobacterium comprises a 1-alkene synthase activity, wherein said 1-alkene synthase is at least 95% identical to SEQ ID NO: 2, and wherein said culture medium comprises an exogenous fatty acid;
(2) exposing said engineered cyanobacterium to light and carbon dioxide, wherein said exposure results in the production of an olefin by said cyanobacterium , and wherein the amount of said olefin produced is greater than the amount that would be produced by an otherwise identical cyanobacterium , cultured under identical conditions but in the absence of said exogenous fatty acid.
11 . The method of claim 10 , wherein said concentration of said fatty acid in said culture medium is at least 1 μg/ml.
12 . The method of claim 11 , wherein said fatty acid is an odd-chain fatty acid.
13 . The method of claim 12 , wherein said odd-chain fatty acid is tridecanoic acid and said olefin is 1-octadecene.
14 . The method of claim 13 , wherein the amount of said 1-octadecene produced is at least 0.039% dry cell weight.
15 . The method of claim 10 , further comprising isolating said olefin from said cyanobacterium or said culture medium.
16 . A method for the biosynthetic production of alkenes, comprising
(1) culturing an engineered microorganism in a culture medium, wherein said engineered microorganism comprises a modification, wherein said modification reduces the activity of a hydrolase having an amino acid sequence that has at least 95% sequence identity to SEQ ID NO:4; and
(2) exposing said engineered microorganism to light and carbon dioxide, wherein said exposure results in the production of alkenes by said engineered microogransims, wherein said alkenes comprise 1-alkenes, and wherein the amount of 1-alkenes produced is greater than the amount that would be produced by an otherwise identical microorganism, cultured under identical conditions, but lacking said modification.
17 . The method of claim 16 , wherein said 1-alkenes include 1-nonadecene.
18 . The method of claim 16 , wherein said microorganism is a cyanobacteria.