Improving bioavailability of lignocellulosic biomass by pretreatment with the marine fungus Chaetomium sp. CS1

Crop straw and waste wood are abundant renewable biomass resources, but their complex lignocellulose composition limits industrial use. This study introduces an eco-friendly solution by bio-converting lignocellulosic biomass into biofuels and biochemicals using Chaetomium sp. CS1, a deep-sea fungus that degrades 55% of alkali lignin in 10 days. Gas chromatography-mass spectrometry (GC-MS) analysis indicated guaiacol as the primary pyrolysis product from G-type lignin, which could be further converted into alkanes and other intermediates. Transcriptomic analysis identified numerous genes encoding ligninolytic enzymes, including highly induced AA3 family enzymes with oxidoreductase and monooxygenase activities, during lignin degradation. A copper-containing nitrite reductase gene was significantly induced, enhancing denitrification and reducing nitrite to aid detoxification. Fungal pretreatment significantly improved the digestibility of sawdust by black soldier fly larvae, enhancing the bioavailability of lignocellulosic materials. These knowledge into fungal lignin degradation provide a basis for efficient lignocellulose pretreatment, enabling high-value biofuel and bioproduct production.