ABSTRACT
Members of the Gram-negative bacterial genus Pseudomonas are ubiquitous in soil and water ecosystems [1]. Their genetic flexibility, versatility in optimizing the usage of a vast array of organic and inorganic compounds, and innate capability to survive under diverse, often trying, environmental conditions are the key factors behind their successful inhabitation of most environmental niches found on our planet [2]. From the point of view of humankind, this genus is intriguing indeed. On the one hand, the ability of Pseudomonas to produce an arsenal of degradative factors makes it one of the most feared pathogens of plants and animals [3, 4]. On the other hand, this same feature, combined with biochemical proficiency for metabolizing toxic hydrocarbons and other compounds, have rendered it one of the most prized organisms for bioremediation of recalcitrant wastes [5–7]. This chapter briefly describes the current taxonomical position and general features of Pseudomonas. This discussion is followed by a section describing some of the prominent members of this genus, and their respective roles in pathogenesis, bioremediation, and plant symbiosis.
