Novel strategies for efficient cornstalk degradation and concurrent resource conversion into chaetoglobosin A by Chaetomium globosum W7

Straw, an abundant lignocellulosic biomass, is a promising renewable feedstock for sustainable production of high-value antibiotics and polysaccharides. In this study, three differentially expressed genes, Cgedg , Cgxyl , and Cglac , were identified through transcriptomic sequencing and bioinformatic analysis, and overexpressed under the constitutive promoter oliC in Chaetomium globosum W7 to generate engineered strains for chaetoglobosin A (cheA) biosynthesis. Notably, the overexpression mutants cxlac10 and cxlac16 demonstrated superior degradation of cornstalk, achieving total removal rates of 39.23 % and 43.47 % after 9 days of incubation, respectively, significantly surpassing the performance of the wild-type strain. Furthermore, the activities of lignocellulose-degrading enzymes, including filter paper hydrolyzing cellulase, carboxymethyl cellulase, xylanase, and laccase, were notably enhanced in these strains. Scanning electron microscopy and Fourier transform-infrared spectroscopy revealed that these overexpression strains could effectively disrupt the recalcitrant lignocellulosic structure. Both cxlac10 and cxlac16 exhibited increased mycelial biomass and significantly enhanced cheA production, when compared with the wild-type strain, with cheA yields increasing from 42.59 mg/L to 209.70 and 217.76 mg/L, respectively. This study offers valuable insights and effective strategies for the bioconversion of lignocellulosic resources into bioactive polyketide alkaloids.