'Columbia University Libraries/Information Services'
Doi
Abstract
Microbiologists have historically been struck by both the beautiful pigmentation of phenazine-producing cultures and the high degree of variability in phenazine production among isolates, conditions, and even repeat experiments. Motivated by an interest in controlling phenazine biosynthesis, they have identified many of the factors that affect the regulation of this process. Phenazine production is controlled by complex regulatory networks. The variability of phenazine production can be explained in part by the effects of environmental conditions on these networks and by strain-specific differences in these networks. In this chapter, we describe the components of a common regulatory cascade that is represented in many phenazine-producing pseudomonads. Membrane sensor proteins and two component sensors control the activity of downstream regulators such as quorum sensing systems and RNA-binding proteins and small RNAs; these cytoplasmic regulators then control the production of phenazine biosynthetic proteins. We highlight examples from specific strains and cases where the mechanistic links may vary among them. We also discuss environmental parameters that have been shown to affect phenazine biosynthesis and compare their effects in different isolates. Ongoing work will further elaborate the details of the environmental sensing and regulatory responses that control production of these dramatically colored compounds. New findings have the potential to support enhanced application of phenazine-producing strains in agriculture, where they promote crop health, and the treatment of infections in which phenazines contribute to bacterial pathogenicity
