Designing sustainable processes for the valorization of industrial and environmental waste streams towards industrializable polyhydroxyalkanoates

In the present study different environmental and industrial waste streams are assessed as feedstock for the production of bioplastics adequate to be used for food packaging applications or for the formation of fully biodegradable garbage bags. For the production of bioplastics i.e. polyhydroxyalkanoates (PHAs), both pure cultures and mixed consortia were assessed in one stage bio-process, i.e. direct bioconversion of the wastes and a two stage bio-process i.e. bioconversion of the wastes after their acidification by mixed acidogenic mixed consortia in mesophilic conditions. For the recovery of PHAs from the microbial biomass cost effective and environmental friendly protocols are investigated aiming to minimal solvent use and maximum recovery yields. The quality of the obtained polymers is assessed via the detailed analysis of their physicochemical and mechanical properties and their characterisation of their behaviour during the moulding process. The health effect and food safety of the PHAs oligomers and final formulated products are also assessed by evaluating their antitumor effects in vitro, on different cell lines known to represent subtypes of colon cancer, as well as their effect on epithelial barrier function by measuring the type 2 protease-activated receptor.