Green transformation of agroindustrial waste into PHB using microbial synergy

Author: DAJANA KUČIĆ GRGIĆ, MATIJA CVETNIĆ, MARINKO MARKIĆ, VESNA OCELIĆ BULATOVIĆ, STELA JOKIĆ, IVICA STRELEC, KRUNOSLAV ALADIĆ, JASMINA RANILOVIĆ, KARLO GRGUREVIĆ, DORA BRAMBERGER

Company/Institution: Prehrambeno tehnološki fakultet Osijek (PTFOS) Sveučilište u Zagrebu, Fakultet kemijskog inženjerstva i tehnologije

Country: CROATIA

e-mail: dkucic@fkit.unizg.hr, mcvetnic@fkit.unizg.hr, mmarkic@fkit.unizg.hr, vocelicbulatovic@fkit.unizg.hr, sjokic@ptfos.hr, ivica.strelec@ptfos.hr, kaladic@ptfos.hr, jasmina.ranilovic@podravka.hr, kgrgurevi@fkit.unizg.hr, dbramberg@fkit.hr /b>

This innovation is based on the development of a circular process for the production of poly(3-hydroxybutyrate) (PHB), a biodegradable biopolymer, using a mixed microbial culture isolated from agroindustrial waste. The process is enhanced by bioaugmentation with Cupriavidus necator and  Pseudomonas  putida, strains known for their high  PHB  accumulation efficiency. The substrate was derived from by-products of fruit and vegetable processing from the food industry which were previously subjected to acid hydrolysis releasing a fermentable mixture of simple sugars. The fermentation was carried out in a bioreactor for five days, during which the optical density, pH and dissolved oxygen concentration were continuously monitored. The resulting biopolymer was confirmed by GC-MS analysis. This innovation represents an efficient, cost-effective and scalable strategy for the valorisation of agroindustrial waste through the production of PHB, which has great potential for the development of biodegradable and compostable packaging materials.