Pseudomonas metabolic diversity captured by GNPS molecular networking

The genus Pseudomonas represents a broad and diverse group of Gram-negative bacteria inhabiting diverse environments including soil, plant surfaces, rhizospheres, aquatic environments, as well as animals. Strains such as P. putida and P. fluorescens are known to protect plants and promote growth.  On the other hand, the genus encompasses the plant pathogen P. syringae and as well as the human opportunistic pathogen P. aeruginosa often associated with cystic fibrosis and nosocomial infections. Many pseudomonads have common features including their ability to utilize an array of organic compounds as energy sources, their capability to endure abiotic stresses and share common specialized metabolite biosynthetic pathways. Because pseudomonads are found in a myriad of environments and possess the genetic capability to biosynthesize a wide range of specialized metabolites, we hypothesize that within the genus Pseudomonas there are unique chemistries evolved from environmental niche necessity. We examined the metabolic profiles of over 260 strains of Pseudomonas isolated from around the world and from an array of environmental niches, and visualized their niche chemistries from a global view using mass spectrometry-based molecular networking. Integrating molecular networking and new genome mining techniques lead to the discovery of four new molecular families and one new analogue from niche specific environments. Expansion of the methods used in this study will soon allow for the prediction of molecular phylogeny, genetic relatedness, and molecular function, to further aid in the global characterization of Pseudomonas and its specialized metabolites.