Project description:Filamentous fungi are promising organisms for lignin degradation and mineralization. However, novel lignin-degrading fungal species are underexplored. Here, we isolated a fungal strain of Curvularia clavata that can utilize lignosulfonate as the carbon source and exhibited a relative high laccase activity during growth on lignosulfonate. Comparative transcriptomic analysis of the WT strain grown on glucose and lignosulfonate indicates that lignosulfonate and/or its metabolites have a significant effect on the gene expression profiles of C. clavata J1. Three regulators of laccase activity were identified, including a methyltransferase CcLaeA and two transcription factors, Rpn-4 and Tah-1. When grown on lignosulfonate, the laccase activity of the CclaeA and rpn-4 disrupted mutants (ΔCclaeA and Δrpn-4) increased by 49.2% and 43.5%, respectively, compared to the wild-type (WT) strain, whereas the tah-1 disrupted mutant (Δtah-1) decreased by 59.2%.
Project description:Lignin, a recalcitrant aromatic biopolymer, represents a promising feedstock for sustainable biorefining. In this study, we characterized the transcriptional response of the fungus Curvularia clavata J1 to alkali lignin (AL) and developed a Cu2+-inducible MCM5–AID base editing system for genome-wide C-to-T and G-to-A mutagenesis. Transcriptomic analysis revealed that AL exposure triggered upregulation of genes involved in electron transport, lipid catabolism, and iron homeostasis. Using droplet microfluidics, we conducted ultrahigh-throughput screening and identified a mutant strain, M6, exhibiting superior phenotypic traits. When cultivated in lignosulfonate medium, M6 showed a 33–36% increase in lipid production and a 75–87% enhancement in laccase activity. Transcriptional profiling further indicated reinforced metabolic pathways related to fatty acid, steroid, and glycerolipid biosynthesis, redirecting carbon flux toward the formation of oil-enriched single-cell protein. This study establishes an integrated platform for lignin valorization and underscores the synergy between synthetic biology and microfluidics for precision engineering of fungal hosts.
Project description:a chromosome-level nuclear genome and organelle genomes of the alpine snow alga Chloromonas typhlos were sequenced and assembled by integrating short- and long-read sequencing and proteogenomic strategy