Enhancing Xylanase and Cellulase Production by Two Locally Isolated Fungal Strains Under Solid-State Fermentation of Water Hyacinth and Sugarcane Bagasse

This study aimed to isolate and identify fungi capable of producing xylanases and cellulases. Thirty-eight fungal strains were isolated from decaying water hyacinth (WH), and two were selected based on their superior enzyme production under solid-state fermentation (SSF). The strains were identified through morphological, cultural, and molecular analyses as Aspergillus austwickii B6 and Trichoderma harzianum M7. Their ribosomal ITS sequences were deposited in GenBank under accession numbers PQ142799.1 for A. austwickii B6 and PQ007458.1 for T. harzianum M7. Enzyme production was evaluated under SSF using eight culture medium variants prepared with natural or pretreated biomasses of WH and sugarcane bagasse (SCB), combined with either NaNO3 or (NH4)2SO4 as nitrogen sources. The maximum xylanase and cellulase activities were 752 and 65 U/g dry matter (DM), respectively, for A. austwickii B6, and 1724 and 152 U/g DM for T. harzianum M7, when cultivated on a low-cost medium composed of pretreated WH, (NH4)2SO4, and a simple mineral salt solution. These findings highlight the potential of locally isolated fungal strains and lignocellulosic residues as cost-effective substrates and inducers of xylanase and cellulase production under SSF and underscore the importance of WH pretreatment to enhance substrate availability and maximize enzyme yields.