Research progress on heat stress response mechanisms in Aspergillus niger

<i>Aspergillus niger</i>, an industrial filamentous fungus recognized as GRAS (Generally Recognized as Safe) and vital for food fermentation and enzyme production, has an optimal fermentation temperature around 30 °C; however, heat stress in industrial systems impairs its cellular viability and reduces target product synthesis efficiency. This review systematically summarizes the multi-level coordinated heat stress response mechanisms of <i>A. niger</i> by integrating existing research findings, revealing that the fungus copes with heat stress via cell membrane remodeling, rapid accumulation of compatible solutes, cAMP/PKA-mediated metabolic reprogramming, protein quality control, and activation of antioxidant defense systems. These mechanisms synergistically enhance <i>A. niger</i>'s heat resistance, while current research still lacks data on early stress signaling events, complete PKA downstream regulatory networks, and multi-omics integration. The review's innovation lies in identifying potential adaptive strategies specific to eukaryotic filamentous fungi (e.g., non-classical membrane regulation) and providing a theoretical basis for improving <i>A. niger</i>'s thermotolerance through metabolic engineering.