Methods and compositions for the recombinant biosynthesis of
The present disclosure identifies methods and compositions for modifying photoautotrophic organisms as hosts, such that the organisms efficiently convert carbon dioxide and light into n-alkanes, and in particular the use of such organisms for the commercial production of n-alkanes and related molecules.
1. An engineered cyanobacterium, wherein said engineered cyanobacterium comprises a recombinant acyl-ACP reductase enzyme and a recombinant alkanal decarboxylative monooxygenase enzyme; and wherein said cyanobacterium, when cultured in the presence of light and carbon dioxide, produces n-alkanes, wherein at least one of said n-alkanes is selected from the group consisting of n-tridecane, n-tetradecane, n-pentadecane, n-hexadecane, and n-heptadecane, and wherein the amount of said n-alkanes produced is between 0.1% and 5% dry cell weight and at least two times the amount produced by an otherwise identical cyanobacterium, cultured under identical conditions, but lacking said recombinant acyl-ACP reductase and alkanal decarboxylative monooxygenase enzymes.
2. The engineered cyanobacterium of claim 1 , wherein said enzymes are encoded by genes which are present in multiple copies in said engineered cyanobacterium.
3. The engineered cyanobacterium of claim 2 , wherein said enzymes are encoded by a plasmid.
4. The engineered cyanobacterium of claim 1 , wherein said enzymes are encoded by genes which are part of an operon, and wherein the expression of said genes is controlled by a single promoter.
5. The engineered cyanobacterium of claim 3 , wherein said enzymes are encoded by genes which are part of an operon, and wherein the expression of said genes is controlled by a single promoter.
6. The engineered cyanobacterium of claim 1 , wherein expression of the recombinant acyl-ACP reductase or alkanal decarboxylative monooxygenase enzymes in said engineered cyanobacterium is controlled by a promoter selected from the group consisting of a cI promoter, a cpcB promoter, a lacI-trc promoter, an EM7 promoter, and an aphII promoter.
7. The engineered cyanobacterium of claim 3 , wherein expression of the recombinant acyl-ACP reductase or alkanal decarboxylative monooxygenase enzymes in said engineered cyanobacterium is controlled by a promoter selected from the group consisting of a cI promoter, a cpcB promoter, a lacI-trc promoter, an EM7 promoter, and a aphII promoter.
8. The engineered cyanobacterium of claim 1 , wherein said engineered cyanobacterium is a thermophile.