Recent Advancements in Fungal Biotechnology for Developing Biopolymers from Waste Biomass: Challenges and Perspectives

The production of plastics globally exceeded 400 million metric tons in 2022, and more than 60% of plastics come from fossil-origin polymers, taking centuries to degrade in the Earth’s ecosystems. On the other hand, agro-industrial activities produce more than 5 billion tons of lignocellulosic and food sector waste every year, but most of it is not tapped properly and ends up being burned, increasing the carbon footprint. However, fungal biotechnology can provide a revolutionary approach in tapping the versatile biocatalytic abilities of fungi, including yeasts, for converting biomass waste into useful bioplastics like polyhydroxyalkanoates (PHAs), polylactic acid (PLA), fungal chitosan, and β-glucans. Bioplastics possess flexible properties, biocompatibility, and biodegradability, making them useful for packaging, biomedical applications, and biocompatible textiles such as bio-cotton. Recent breakthroughs in systems biology studies and genome editing through CRISPR-Cas9 systems, as well as adaptive laboratory evolution (ALE) efforts, have made it possible to increase polymer production yields, substrate tolerance, and robustness in fungal host systems such as Aspergillus niger, Rhizopus oryzae, and Yarrowia lipolytica. This chapter reviews the current trends in biosynthesis using biopolymers from fungal sources and metabolically engineered approaches, particularly from waste biomass. This chapter identifies important challenges ranging from substrate diversity to enzyme inhibition and scale-up, while formulating holistic approaches that integrate strain design derived from omics analysis tools, bioreactor development, and closed-loop bioeconomy concepts. Insights into regulatory frameworks, life cycle analysis, and techno-economic analysis will be investigated in the context of the strategic importance of fungal biotechnology in moving the entire material science field toward sustainability.