Polyhydroxyalkanoate‐Based Substrate Bags for Sustainable Mushroom Cultivation

The escalating global demand for plastics has profoundly impacted various industries, including mushroom cultivation, which predominantly relies on plastic substrate bags. Improper disposal of these plastic bags, a byproduct of traditional mushroom cultivation techniques, has significantly contributed to environmental pollution, highlighting the urgent need for sustainable alternatives. This study explores the potential of polyhydroxyalkanoate (PHA) as an eco‐friendly substitute for conventional plastic substrate bags in mushroom cultivation. Poly(3‐hydroxybutyrate‐ co ‐13 mol% 3‐hydroxyhexanoate) [P(3HB‐ co ‐13 mol% 3HHx)] was synthesized using the Cupriavidus necator transformant strain Re2160/pHT1‐C BP‐M‐CPF4 , with waste cooking oil (WCO) as the sole carbon source in a 13 L bioreactor. The synthesized PHA underwent comprehensive characterization before being fabricated into substrate bags for cultivating Pleurotus ostreatus . A detailed investigation into the biodegradability of PHA films, conducted under varying ratios of spent mushroom substrate (SMS) and soil, identified two PHA‐degrading bacteria: Acidovorax sp. and Schlegella sp. This study underscores the potential of PHA‐based mushroom substrate bags as a sustainable solution to mitigate plastic pollution in mushroom cultivation. By fostering environmentally conscious practices, the findings pave the way for broader applications of PHA‐based materials across diverse industries, advocating for a circular economy and sustainable development.