**8. Conclusions**

CGP is well researched and its occurrence in cyanobacteria is known for more than 100 years. However, many questions are still open. Most obviously, the cell biology of the CGP granules remains largely unknown. In the last decades, research on CGP mainly focused on biotechnological purposes, like strain or process optimization. Most work has been carried out with short-chain CGP from recombinant producer strains; however the biophysical properties of the long-chain native CGP remain largely unexplored. So far, heterotrophic bacteria were mainly used to produce industrial biocompounds including CGP. In this chapter, we discussed the possibility of a cyanobacterial CGP production strain. The main disadvantages of cyanobacteria, their slower growth and the low abundance of product can be compensated using genetic engineering together with appropriate production processes. Future industry has to cope with the manifold challenges to counteract environmental pollution and climate change. The use of cyanobacteria in CGP production and, more generally, in biotechnological applications for bioproduct synthesis provides an environmentally friendly alternative to conventional biotechnological approaches.
