BACKGROUND:Cyanophycin (CGP) is a sustainable polymer that can be converted to a derivative with reduced arginine content, or to completely biodegradable poly-aspartic acid, which can substitute for non-biodegradable polyacrylates. In nature, it is produced by most cyanobacteria; however, these microbes are not suitable for large-scale production due to slow growth and low polymer content. RESULTS: Cyanophycin synthetase gene (cphA) from Anabaena variabilis ATCC 29413 was PCR amplified and cloned into Escherichiacoli.Differentrenewablemediacomponents,suchassoybeanmeal,potatowastesandcorn-derivedzein hydrolysate, were evaluated for their feasibility for CGP production at shake flask level. The optimized conditions were then tested in a 7 L bioreactor; a maximum cell weight of 10.2 g L-1 was obtained. CGP comprised 23 g g-1 of cell dry matter (CDM) with molecular weight between 21.5 and 31 kDa and was composed of aspartic acid, arginine and lysine in the ratio of 1.05:1:0.2 (mass basis). CONCLUSION: The efficient use of renewable biomass for cyanophycin production could achieve competitive price, and in return, promote the use of this platform chemical to produce innovative polymers and materials.
- cyanophycin; fermentation; platform chemical; recombinant E.coli; amino acids
Available at: http://works.bepress.com/amit_kumar/3/