Investigation of singlet-oxygen-responsive genes in the cyanobacterium Synechocystis PCC 6803.

Singlet oxygen (O) is an important reactive oxygen species whose formation by the type-II, light-dependent, photodynamic reaction is inevitable during photosynthetic processes. In the last decades, the recognition that O is not only a damaging agent, but can also affect gene expression and participates in signal transduction pathways has received increasing attention. However, contrary to several other taxa, O-responsive genes have not been identified in the important cyanobacterial model organism Synechocystis PCC 6803.

Increased sensitivity of heavy metal bioreporters in transporter deficient Synechocystis PCC6803 mutants.

The detection and identification of heavy metal contaminants are becoming increasingly important as environmental pollution causes an ever-increasing health hazard in the last decades. Bacterial heavy metal reporters, which constitute an environmentally friendly and cheap approach, offer great help in this process. Although their application has great potential in the detection of heavy metal contamination, their sensitivity still needs to be improved.

A single plasmid based CRISPR interference in Synechocystis 6803 - A proof of concept.

We developed a simple method to apply CRISPR interference by modifying an existing plasmid pCRISPathBrick containing the native S. pyogenes CRISPR assembly for Synechocystis PCC6803 and named it pCRPB1010. The technique presented here using deadCas9 is easier to implement for gene silencing in Synechocystis PCC6803 than other existing techniques as it circumvents the genome integration and segregation steps thereby significantly shortens the construction of the mutant strains.