GNPS - Growth Rate-Dependent Coordination of Catabolism and Anabolism in the Archaeon Methanococcus maripaludis under Phosphate Limitation

Catabolic and anabolic processes are finely coordinated in microbes to provide optimized fitness under varying environmental conditions. Understanding this coordination and the resulting physiological traits identifies fundamental microbial strategies of acclimation. Here, we characterized the systems-level physiology of Methanococcus maripaludis, a niche-specialized methanogenic archaeon, at different growth rates under phosphate (i.e., anabolic) limitation. We observed a decoupling of catabolism and anabolism resulting in lower biomass yield relative to catabolically limited cells. In addition, the mass abundance of several coarse-grained proteome sectors exhibited a linear relationship with growth rate, most notably ribosomes and their biogenesis. Accordingly, cellular RNA content also correlated with growth rate. Although the methanogenesis proteome sector was invariant, the metabolic capacity for methanogenesis correlated with growth rate suggesting translationally independent regulation. These observations are in stark contrast to the physiology of M. maripaludis under formate (i.e., catabolic) limitation, where cells keep an invariant proteome including ribosomal content and a high methanogenesis capacity across a wide range of growth rates. Our findings reveal that although highly niche-specialized, M. maripaludis employs fundamentally different strategies to coordinate global physiology during anabolic phosphate and catabolic formate limitation.