Multidimensional Analysis of the High-Temperature Response Mechanism in Acetobacter pasteurianus TCBRC 103: Integrating Physiological Characterization and Transcriptomics

Acetic acid bacteriaare core microorganisms in vinegar brewing, yet their fermentation performance is often limited by high-temperature stress during acetic acid fermentation. This study investigated Acetobacter pasteurianus TCBRC 103, a strain exhibiting exceptional thermal tolerance, to systematically elucidate its stress response mechanisms under 42heat shock through integrated physiological characterization and transcriptomic analysis. Physiological assays demonstrated that TCBRC 103 maintained high cell viability, membrane integrity, and key membrane-bound enzyme (ADH, ALDH) activities under high temperature, alongside robust antioxidant capacity evidenced by lower reactive oxygen species (ROS) and malondialdehyde (MDA) levels, and elevated glutathione (GSH) content and DPPH radical-scavenging ability. Transcriptomic profiling further revealed that heat stress induced the upregulation of genes involved in energy metabolism, particularly in the TCA cycle and oxidative phosphorylation pathways. Concurrently, genes encoding ribosomal proteins and transposases were significantly downregulated, reflecting sophisticated regulatory strategies in energy allocation, protein homeostasis maintenance, and genomic stability. This multi-dimensional study elucidates the thermotolerance mechanisms of A. pasteurianus TCBRC 103, providing a theoretical foundation for the targeted breeding of heat-resistant AAB and their industrial applications.