Microbial Competition and Nutrient Limitation Remodel the Volatilome of Kluyveromyces marxianus

The use of Kluyveromyces marxianus in mixed cultures for fermentation processes has become increasingly relevant. This yeast is characterized by rapid growth, thermotolerance, broad sugar utilization, and the ability to produce aroma-active compounds. In this study, we evaluated changes in the growth and volatilome of a K. marxianus strain isolated from agave fermentation under microbial competition induced by co-cultivation interactions and nutritional limitation induced by a nutrient-deficient medium. The results indicate that these stress factors are significant drivers of metabolic changes, leading to substantial increases in the concentrations of key aromatic compounds. Stress-free conditions favor cell growth and the production of stable, reproducible volatile profiles, which is advantageous for batch-to-batch consistency (as in wine or mezcal production). While microbial competition and nutritional limitation induce reduced cell growth and loss of viability, they also lead to increased aromatic diversity, particularly the synthesis of β-phenethyl acetate, ethyl octanoate, and ethyl hexanoate. These findings demonstrate a relationship between environmental stress and the development of volatile profile complexity, offering new insights into harnessing stress-induced changes in the volatilome to optimize the sensory profile of traditional fermentations.