Research Projects

Plastic bioenergetics is crucial for bacterial survival and has evolved under various biogeochemical selection pressures. The Great Oxidation Event (GOE) led to the rise in atmospheric oxygen, which was toxic to primitive organisms and resulted in a significant extinction event. However, the high reduction potential of oxygen made it an ideal electron acceptor for the electron transport chain (ETC). Post-GOE, many microbes acquired ubiquinone (UQ), a non-aromatic, 1,4-benzoquinone-based isoprenoid quinone with higher reduction potential than ancestral naphthoquinone (NQ). The physiological utilization of UQs is unknown, and an inhibitor screening study found an association between UQ presence in some bacterial species and their tolerance for an analog of 1,4-benzoquinones. The objective is to delineate the physiological adaptation leading to the assimilation of UQ in bacterial energy metabolism. Genetic engineering and an adaptive laboratory evolution approach will be used to study the positive and negative effects of acquiring the UQ biosynthetic pathway in Bacillus subtilis. The study will involve multi-omics characterization of the evolved strains. Adaptive plasticity in bacterial physiology is central to infectious disease, as both host defense strategies and antibiotic-aided approaches involve ROs assault. The UQ-based ETC provides protection against reactive radicals, making it an adaptive advantage in various stressed environments. UQ's metabolic resource-conservative nature makes the knowledge relevant to strain engineering for fermentation applications.