Abstract
A circular bioeconomy approach is essential to slowing down the fearsome ongoing climate change. Replacing polymers derived from fossil fuels with biodegradable biobased polymers is one crucial part of this strategy. Cyanophycin is a polymer consisting of amino acids produced by cyanobacteria with many potential applications. It consists mainly of aspartic acid and arginine, however, its composition may be changed at the production stage depending on the conditions of the polymerization reaction, as well as the characteristics of the enzyme cyanophycin synthetase, which is the key enzyme of catalysis. Cyanophycin synthetases from many sources were expressed heterologously in bacteria, yeast and plants aiming at high yields of the polymer or at introducing different amino acids into the structure. Furthermore, cyanophycin can be modified at the post-production level by chemical and enzymatic methods. In addition, cyanophycin can be combined with other compounds to yield hybrid materials. Although cyanophycin is an attractive polymer for industry, its usage as a sole material remains so far limited. Finding new variants of cyanophycin may bring this polymer closer to real-world applications. This short review summarizes all modifications of cyanophycin and its variants that have been reported within the literature until now, additionally addressing their potential applications.
Highlights
Cyanophycin, referred to as cyanophycin granule polypeptide or multi-L-arginyl-polyL-aspartate, is a non-ribosomally synthesized amino acid polymer found in cyanobacteria and some heterotrophic bacteria
2017 thoroughly characterized material properties of cyanophycin and suggested its usefulness as part of copolymers–cyanophycin could contribute to the final material with its strength
Tseng et al, 2016 showed that crosslinking cyanophycin led to decrease of brittleness, this technique may widen the applicability of cyanophycin
Summary
Cyanophycin, referred to as cyanophycin granule polypeptide or multi-L-arginyl-polyL-aspartate, is a non-ribosomally synthesized amino acid polymer found in cyanobacteria and some heterotrophic bacteria. It serves microorganisms as a temporary storage compound primarily for nitrogen, and for energy and carbon (Merritt et al, 1994; Li et al, 2001; Frommeyer et al, 2016). It is composed of aspartic acid in the backbone and arginine residues as the side chains (Figure 1 Figure 1A). The γ-carboxylic acid is activated by phosphorylation and arginine is attached at this position by an isopeptide bond (Forchhammer and Watzer, 2016; Frommeyer et al, 2016; Du et al, 2019)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
