Interfaculty Institute of Microbiology and Infection Medicine

Biotechnological production of native Cyanophycin from Cyanobacteria

Dr. Björn Watzer

The importance of environmentally friendly production processes and biodegradable plastics increases more and more. Hence, Cyanobacteria are expected to play a major role in future industry, due to their ability to use sunlight and CO2 as energy and carbon source. Cyanobacteria have been identified as rich source of various biologically active compounds, biofertilizers, bioplastics, energy, food and feed. Most cyanobacteria are able to accumulate industrial relevant biopolymers like PHA or Cyanophycin.

Cyanophycin is a non-ribosomal synthesized polyamide consisting of the two amino acids, aspartate and arginine, forming a poly-l-aspartic acid backbone with arginine side chains. It serves as a dynamic nitrogen reservoir in most diazotrophic and non-diazotrophic cyanobacteria as well as in some heterotrophic bacteria. Cyanophycin accumulates in form of opaque and light-scattering cytoplasmic granules. Cyanophycin has been noticed of potential industrial use. This biodegradable polyamide could substitute synthetical polymers with similar properties in fields of medical, food, feed and pharmaceutical industry. Further, Cyanophycin can serve as a natural source of amino acids such as arginine and aspartate; and the poly-aspartate backbone of this polymer could also be used as a biodegradable substitute for polyacrylates.

Our Institute developed a high potent cyanobacterial Cyanophycin producer strain, named Synechocystis strain BW86. Under optimized conditions strain BW86 could accumulate up to 57% Cyanophycin per cell dry mass. Strain BW86 allows us an environmentally friendly production of Cyanophycin in a large scale. With this process and the support of academically and industrial cooperation partners we are exploring further potential applications for Cyanophycin.