Elucidating the Metabolism of Sulfolobus Solfataricus Using 13C Metabolic Flux Analysis

Sulfolobus solfataricus is a highly thermophilic archaeon with optimal growth temperature of about 80-85°C. A key characteristic of Sulfolobus solfataricus is its ability to grow in low pH environments (pH<3). This presents new opportunities for industrial application in lignocellulosic biomass processing. In this study, the cell physiology and metabolism of Sulfolobus solfataricus was investigated. First, an optimized minimal growth medium was developed for growing the cells in aerobic batch culture. Next, growth experiments were performed with different C5 and C6 sugars. Based on these experments, we determined that Sulfolobus solfataricus could grow efficiently on multiple sugars (glucose, xylose, cellobiose). The metabolism of Sulfolobus solfataricus was then investigated in detail using 13C isotope tracing. Specifically, parallel labeling experiments were performed using 13C-glucose and 13C-xylose tracers, followed by mass spec analysis and 13C-metabolic flux analysis to quantify intracellular metabolic fluxes. The 13C-flux results provided a detailed picture of the activity of metabolic pathways in this organisms during aerobic growth on glucose and xylose. Overall, the insights obtained from this study will enable future metabolic engineering studies of Sulfolobus solfataricus with potential biotechnological applications.