Sapphire Energy publishes scientific paper on chloroplast genome

By Erin Voegele | December 06, 2011

Calif.-based Sapphire Energy Inc. recently announced that its white paper has been published by Nucleic Acids Research Journal, a scientific publication. The white paper, titled, “An exogenous chloroplast genome for complex sequence manipulation in algae,” outlines the methodology for the design, construction, modification and cellular introduction of the chloroplast genome from the green algae Chlamydomonas reinhardtii. Chloroplasts, found in plants and algae, are responsible for producing organic molecules from atmospheric carbon dioxide.

According to Sapphire, using the methodology described in the white paper, the authors were able to simultaneously modify multiple independent regions, including genes that encode core subunits of the photosynthetic apparatus, in the chloroplast genome of living algae cells. The company further states that this work should allow for the creation of genetic diversity in all regions of a chloroplast genome of potentially any photosynthetic organism.

In the white paper, the authors specify that through the extensive use of sequence stabilization strategies, they were able to assemble the ex vivo genome in yeast from a collection of overlapping fragments. The assembled genome was them moved into bacteria before being transformed into the algae cells. “Once transformed into algae, the substituted genome recombines with the endogenous genome, resulting in a hybrid plastome comprising modifications in disparate loci,” said the authors in the report.

In a press release describing the achievement, Sapphire Energy notes that chloroplast genomes present a unique opportunity for the field of synthetic biology. “In a single, relatively small molecule, they encode the most important genes of photosynthesis, nature's principle method for converting sunlight into chemical energy,” the company stated in the release. “These naturally minimized, manipulable genomes are of great interest for metabolic engineering for foods, fuels, and myriad bioproducts, and are ideally suited target for synthetic biology.”

"With this breakthrough, Sapphire Energy has shown that it is possible to make algae—the world's most efficient photosynthetic organism—even more efficient," said Jason Pyle, Sapphire Energy founder and CEO. "This work represents the first steps toward a novel approach for creating genetic diversity in any or all regions of a chloroplast genome, and may have applications in other plants."  

A full copy of the white paper can be downloaded from the Nucleic Acids Research Journal website.