Lignocellulose is the most abundant renewable carbon resource in nature. However, its structural recalcitrance, arising from the complex association of cellulose, hemicellulose, and lignin, results in high pretreatment costs and inefficient enzymatic hydrolysis, thereby limiting its high-value utilization. The rumen harbors a diverse anaerobic microbial community with efficient lignocellulose-degrading capacity, interconnected metabolic networks, and considerable functional adaptability, making the rumen microbiome a promising biological platform for lignocellulose conversion. This review systematically summarizes the mechanisms of lignocellulose degradation by rumen microorganisms, the metabolic pathways underlying value-added chemical production, and the process-, community-, and genetic-level strategies used to improve lignocellulose conversion performance. It further discusses major constraints on the development of rumen-derived bioconversion systems, including the instability of in vitro microbial communities, limited control over metabolic flux, and difficulties in process scale-up. Finally, the potential of multi-omics analyses and synthetic biology to improve community stability, metabolic controllability, and product selectivity is highlighted. This review provides theoretical and technical guidance for developing sustainable lignocellulose valorization processes based on rumen microorganisms.

Saccharomyces cerevisiae has been applied widely in industrial production; however, a variety of stressors and inhibitors limit its application. Therefore, exploring the tolerance mechanism of S. cerevisiae to various environmental adverse factors and improving its tolerance by various methods such as genetic modification are crucial for improving the robustness and fermentation ability of S. cerevisiae in industrial production. This article reviews the tolerance mechanism of S. cerevisiae to osmotic pressure, ethanol, high temperature, organic acid, reactive oxygen species (ROS) and sulfur dioxide, analyzes tolerance genes related to environmental stress in S. cerevisiae and summarizes the current directions in research on the tolerance mechanism of S. cerevisiae. In the future, the molecular mechanism and functional network of strain adaptation to the environment will be studied by systems biology and genetic engineering technology, which will provide theoretical and practical guidance for improving the stress resistance and fermentation ability of S. cerevisiae in industrial production.