Method for converting waste substrates into biodegradable bioplastics

The invention refers to a system for the selective transfer of volatile fatty acids (VFA) from an anaerobic fermenter into a polyhydroxyalkanoates production system based on microbial mixed cultures (MMC). This system is able to produce a stable production of PHA containing bacteria.

Title of the patent Process for the transfer of volatile fatty acids through an organic-based liquid membrane
Thematic area Agro-food
Ownership Alma Mater Studiorum – Università di Bologna
Inventors Cristian Torri, Chiara Samorì, Paola Galletti, Emilio Tagliavini
Protection Italy (opportunity for seeking international patent protection)
Licensing status Available for licensing agreements
Keywords Volatile Fatty Acids, Carboxylic Acids, Polyhydroxyalkanoates, Biopolymers, Agro-wastes
Filed on Sep 24, 2018

To date, many systems for extracting VFA from aqueous solutions (e.g. anionic exchange resins) are known. Obtaining these VFAs in a usable form is more difficult and normally uses a lot of thermal energy or additional chemical reagents (e.g. NaOH).

The pertraction system involves extracting the VFA with a mixture of biodiesel or vegetable oil containing additives and subsequently releasing them into a slightly basic aqueous solution. This aqueous solution is used to obtain PHA within a mixed microbial culture system (MMC) which regenerates at the same time. The system is therefore a closed system, which takes VFA from an anaerobic system and produces a biomass enriched in PHA.

The system does not use stoichiometric reagents and has a low energy consumption linked only to the movement of the liquid membrane. If associated with a simple pH control, the use of a VFA pertraction system allows to obtain a standard solution of VFA from a variable fermentable material in terms of composition. This standard solution represents the ideal substrate for the production of PHA.