Sustainable bio-production of styrene from forest waste

•A new way of utilizing abundantly available tree bark.•Styrene production using forest waste biomass.•A strain of Penicillium expansum produced styrene when grown on tree bark media.•52.5μg/h styrene production rate from fungus grown on 10g bark media. A strain of Penicillium expansum was studied for the production of styrene using forest waste biomass as a feeding substrate. The fungal strain was cultivated on bark of various trees supplemented with yeast extract and the volatiles produced were collected on Tenax TA and analyzed by gas chromatography–mass spectrometry. Fungus cultured on grated soft bark of pine (Pinus sylvestris) stems (GPB) and mature bark of oak (Quercus robur) supplemented with yeast extract produced relatively the highest amounts of styrene. The maximum styrene production rate was 52.5μg/h, 41μg/h and 27μg/h from fungus cultivated on 50mL liquid media with 10g GPB or mature bark of oak and potato dextrose broth respectively. These promising results suggest that the fungal strain could be used to produce “green” styrene plastics using renewable forest waste biomass.