Utilization of High-Lignin Mutant Straw by White-Rot Fungus Pleurotusostreatus GEMB-PO1

• 1、Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082

Abstract：Agricultural production generatessubstantial amounts of crop straw, whose efficient transformationand utilization face challengesin environmental sustainabilityand economic feasibility.White-rot fungi (WRF), owing to their powerful lignocellulose-degrading capacity, exhibit great potential in straw treatment and resource recovery. However, the mechanisms underlying their efficient straw degradation remain unclear.This study employed the white-rot fungus Pleurotusostreatus GEMB-PO1 to comparatively analyze its effects on wild-type rice straw and a lignin-rich brittle mutant straw, while investigating the stimulatory role of straw co-cultivation on laccase production. Field-emission scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) demonstrated that the fungus exhibited stronger colonization, growth, and degradation activity on wild-type straw, causing more pronounced structural damage compared to the lignin-rich mutant. Notably, the mutant straw significantly enhanced laccase secretion by GEMB-PO1.By utilizing straw substrates withdifferential lignin content, this study innovatively elucidatedthe structural modifications inducedbyP.ostreatus treatment, therebyadvancing the mechanistic understandingof fungal straw degradation.These findings provide crucialtheoretical and practical guidancefor developing efficient WRF-based systems for organic pollutant degradation and optimizing straw bioconversion technologies..

Keywords： White rot fungi Rice straw Field scanning electron microscopy Fourier infrared spectroscopy Thermogravimetric analysis Extracellular laccase