Microorganisms with increased photosynthetic capacity
Microorganisms with increased photosynthetic capacity are described. Increased photosynthetic capacity is achieved by down-regulating activity of the RpaB pathway. The microorganisms include Cyanobacteria, including genetically-modified Cyanobacteria.
1. A genetically-modified Cyanobacterium comprising an exogenous nucleotide sequence comprising SEQ ID NO: 23 that expresses an N-terminal fragment of RpaB polypeptide comprising the amino acid sequence of SEQ ID NO: 2, and wherein the N-terminal fragment does not comprise a DNA binding domain or a functional DNA binding domain, under the control of a promoter that results in down-regulated RpaB pathway activity in the genetically-modified Cyanobacterium as compared to a Cyanobacterium of the same species without the exogenous nucleotide sequence.
2. The genetically-modified Cyanobacterium of claim 1 wherein the promoter is
(a) an inducible promoter; or
(b) endogenous to the genome of the genetically-modified Cyanobacterium.
3. The genetically-modified Cyanobacterium of claim 1 wherein the genetically-modified Cyanobacterium is a Cyanobacterium selected from Synechococcus elongatus, Arthrospira maxima, Arthrospira platensis , and Cyanobacterium aponinum.
4. The genetically-modified Cyanobacterium of claim 1 wherein the genetically-modified Cyanobacterium has increased
(a) photosynthetic capacity as compared to a Cyanobacterium of the same species without the exogenous nucleotide sequence; and/or
(b) photosynthetic biomass accumulation from photoautotrophic growth as compared to a Cyanobacterium of the same species without the exogenous nucleotide sequence.