C6‑HSL enhances BPA tolerance in Pseudomonas asiatica: an integrative Raman‑DIP and transcriptomic study

Bisphenol A (BPA) is a pervasive contaminant found in various environmental media, exhibiting extensive biotoxicity to microorganisms. Consequently, it would be of paramount significance to investigate broader methods and mechanisms for enhancing bacterial resistance to stress. This study found that BPA stress can lead to the downregulation of over 59 % of functional genes and result in a maximum reduction of cell viability and ATP content in the strain. Conversely, 10 μM C6-HSL has been observed to enhance the strain's resistance to BPA toxicity stress most significantly by inducing up-regulation of genes of the pathways of antioxidant damage, amino acid synthesis and metabolism, and energy supply, and increased the cell viability by 1.13-fold. The up-regulated expression of antioxidant stress genes directly enhance the bacterial resistance to BPA toxicity, resulting in a 17.28 % reduction in intracellular ROS. On this basis, C6-HSL could increase the expression levels of genes related to amino acid and energy synthesis, as well as enzyme activities. This promotes intracellular metabolic processes and energy production, ultimately elevating the ATP content within the strain by 12.21 %. This study is the first to confirm the function of C6-HSL in enhancing bacterial resistance to BPA toxicity and innovatively combines Raman-DIP, transcriptomics, and enzyme activity to systematically analyse the regulatory mechanisms of C6-HSL on the bacterial antioxidant system, amino acid system, and energy system. The study provides methodological references and theoretical foundations for comprehensively enhancing the detoxification ability of microorganisms.