Politecnico di Torino - Corso Duca degli Abruzzi, 24 - 10129 Torino, ITALY

+39 011 090 6100 info@tech-share.it

Method for PHA recovery and purification from mixed microbial cultures

bioplasticsEnzymesgreen solventspolyhydroxyalkanoatesPurificationPurificazioneSupercritical fluids


An innovative technique for the separation and purification of polyhydroxyalkanoates from mixed microbial biomass. The technology used exploits, alone or in combination, some separation methods typical of green chemistry and with low environmental impact. In this way the use of chlorinated solvents is replaced by green type reagents. Extraction with supercritical fluids is a Green Technology that guarantees environmental sustainability to the process and a high degree of quality and purity of the extracted product.

Technical features

Purification techniques can be used for the recovery of polyhydroxyalkanoates produced from mixed microbial cultures. Freeze-dried and finely ground biomass is treated with aqueous solutions and / or green solvents. The technique may includes one or various steps, depending on the degree of purity of the polymer to be obtained, it can be applied to the rapid expansion of a supercritical solution (RESS – Rapid Expansion of Supercritical Solutions) applied to pharmaceutical powders and to induced precipitation. from supercritical anti-solvent (SAS – Supercritical Anti-Solvent) starting from a homogeneous solution of substances of pharmaceutical interest and from a saturated solution with gas (PGSS – Particles from Gas Saturated Solutions). The developed technology was validated on a laboratory scale, corresponding to the TRL4 level.

Possible Applications

  • Extraction of aromas and essences from vegetable matrices and seed oils;
  • Pasteurization of food matrices;
  • Column fractionation, micronization, precipitation, purification;
  • Microencapsulation and coating of drugs for controlled release systems.


  • High solvent power;
  • Non toxicity;
  • Non flammability;
  • Non explosive.