Increasing the carbon fixation rate

We came to the conclusion that one way of solving these questions was to utilize the machinery already existing in photosynthetic cells. In this way the organism could hopefully survive in its natural environment, while fixating carbon to a larger extent when compared to native carbon fixation rates. Since one of our team members was already familiar with photosynthetic bacteria, we chose to exploit this knowledge and decided to continue the work with the organism Synechocystis sp. PCC 6803 in mind.

What measure could we take to ensure the biosafety of our GMO?

Biosafety is an important issue for our project, as the goal would be to use the genetically modified organism (GMO) outside of the lab to fixate carbon. Before GMOs are allowed for use in natural environments, an extensive line of tests and validations are needed to ensure that they do not have any unwanted effects on the surrounding environment. Horizontal gene transfer (HGT) is one example of such an effect. This is the transmission of DNA between genomes, and is distinguished from vertical gene transfer were generic material is transferred from parent to offspring. Considering evolution and adaptation, HGT has been essential for the development of the earth’s species to what they are today, but introducing synthesized and genetically modified material into the mix can lead to loss of biological integrity. Moreover, the number and severity of the consequences of introducing synthesized and modified genomes are largely unknown.

While working with the genetically modified organisms in the lab, it is imperative that the accidental release of these organisms from the controlled environment is avoided to the greatest possible extent. This is controlled by strict laboratory routines for working with, and disposing of, GMOs. Although the Synechocystis sp. PCC 6803 cyanobacteria would struggle to survive outside of the laboratory, precautions were taken when disposing/cleaning of any material containing or been in contact with the GMO.

Before further development of the genetically modified cyanobacteria can be used to fixate carbon in a less controlled environment, it is presumed that removal of antibiotic resistance cassettes from the genome (used to make the initial genetic modifications) would have to be undertaken. Additionaly, a way of preventing HGT from the cyanobacteria to other organisms would be of importance since the strain would carry non-native, synthesized and heavily modified genetic information that could be detrimental to ecological integrity. Furthermore, a thorough analysis of the organisms toxicity with the exogenous DNA incorperated into the genome would prevent potential natural catastrophes. Despite this, wild type Synechocystis sp. PCC 6803 is a non-toxic, non-pathogenic cyanobacterium which poses no known threat to mammalian health or the environment.