Fecha de publicación: 03/12/2024 Fuente: Polymers Polymers, Vol. 16, Pages 3407: Producing and Characterizing Polyhydroxyalkanoates from Starch and Chickpea Waste Using Mixed Microbial Cultures in Solid-State Fermentation
Polymers doi: 10.3390/polym16233407
Authors:
Karlo Grgurević
Dora Bramberger
Martina Miloloža
Krešimir Stublić
Vesna Ocelić Bulatović
Jasmina Ranilović
Šime Ukić
Tomislav Bolanča
Matija Cvetnić
Marinko Markić
Dajana Kučić Grgić

The environmental impact of plastic waste is a growing global challenge, primarily due to non-biodegradable plastics from fossil resources that accumulate in ecosystems. Biodegradable polymers like polyhydroxyalkanoates (PHAs) offer a sustainable alternative. PHAs are microbial biopolymers produced by microorganisms using renewable substrates, including agro-industrial byproducts, making them eco-friendly and cost-effective. This study focused on the isolation and characterization of PHA-producing microorganisms from agro-industrial waste, including chickpeas, chickpeas with bean residues, and starch. Screening via Sudan Black staining identified PHA-accumulating strains such as Brevibacillus sp., Micrococcus spp., and Candida krusei, among others. To assess the potential for PHA biosynthesis, solid-state fermentation (SSF) was conducted using agro-industrial waste as substrates, along with a mixed culture of the isolated microorganisms. The highest observed yield was a PHA accumulation of 13.81%, achieved with chickpeas containing bean residues. Structural and thermal characterization of the PHAs was performed using Fourier-transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). FTIR-ATR spectra indicated polyhydroxybutyrate (PHB), suggesting it as the synthesized PHA type. This study highlights the potential of agro-industrial waste for sustainable PHA production and eco-friendly bioplastics.