Temperature-associated metabolic responses of Aspergillus cristatus revealed by untargeted LC-MS metabolomics.

Temperature is a key environmental factor affecting fungal growth, reproduction, and metabolism. In this study, the industrially important fungus Aspergillus cristatus was investigated by integrating physiological phenotyping with liquid chromatography-mass spectrometry (LC-MS)-based untargeted metabolomics to systematically characterize its morphological traits, antioxidant activity, and untargeted metabolic profiles at 20 °C, 25 °C, 30 °C, and 35 °C. The results showed that approximately 30 °C was the most favorable temperature for the growth of Aspergillus cristatus. Metabolomic analysis indicated that Aspergillus cristatus exhibited a pattern of metabolic redirection under different temperature conditions, reflecting a multilayered and coordinately changing metabolic mode associated with temperature adaptation. At low temperatures (20 °C and 25 °C), unsaturated lysophospholipids, such as PC O-18:2, accumulated substantially, suggesting their involvement in membrane adaptation, whereas high temperature was associated with changes in specific phospholipid molecules. In terms of oxidative stress defense, flavonoid- and phenolic-related metabolites showed more prominent changes under low and optimal temperatures, whereas glutathione-related metabolites increased significantly at high temperature, indicating a greater reliance on glutathione-associated antioxidant defense. Regarding energy and osmotic balance, reserve carbohydrates accumulated at the optimal temperature, consistent with coordination between growth and stress resistance, whereas high-temperature stress was associated with a shift toward sugar alcohol accumulation and a metabolic pattern consistent with metabolic deceleration. This study presents the metabolic changes of Aspergillus cristatus under different temperature conditions from a systems-level metabolic perspective and suggests that Aspergillus cristatus may adapt to environmental change by coordinating growth-related metabolism with stress defense-related metabolism. In addition, these findings may provide a reference for future studies on fermentation regulation and stress resistance in Aspergillus cristatus.