In P. putida, the substrates of the CFA Pictilisib datasheet synthase, cis-unsaturated fatty acids (cis-UFAs), are also substrates for another stress-related enzyme, the cis–trans isomerase (CTI). Despite using the same substrates, we have found that the activity of the CTI is not limited by the CFA synthase activity and vice versa. For instance, in a cfaB knockout mutant, the amount of trans-UFAs synthesized after a specific stress was no higher than in the parental background despite the fact that there are more cis-UFAs available to be used by the CTI as substrates. In this regard,

in a cti-deficient mutant background, the levels of CFAs were similar to those in the parental one under the same conditions. Pseudomonas species colonize many different environments and consequently have diverse lifestyles. Species belonging I-BET-762 mouse to this genus have been described as opportunistic human and plant pathogens (such as Pseudomonas aeruginosa) (Yahr & Greenberg, 2004; Attila et al., 2008; Yang et al., 2008), beneficial to plants (Pseudomonas putida or Pseudomonas fluorescens) (Molina et al., 2000; Gal et al., 2003; Giddens et al., 2007; Jones et al., 2007) or plant pathogens (Pseudomonas syringae) (Uppalapati et al., 2008). In

all the different environments these bacteria can inhabit, they are threatened by diverse biotic and abiotic factors; however, bacterial cells have developed mechanisms to cope with these threats (Ramos et al., 2002; Daniels et al., 2010). The ability to colonize multiple habitats reflects a high adaptability and this trait correlates with the comparative high number of sigma

factors present in bacteria (Ramos-González & Molin, 1998; Martinez-Bueno et al., 2002; Venturi, 2003; Potvin et al., 2008). One extensively Lonafarnib supplier studied alternative sigma factor is RpoS (σS or σ38), which controls the expression of genes involved in survival to starvation and other stresses that lead to growth reduction (stationary phase). The levels of RpoS in Escherichia coli increase at the onset of the stationary phase and are tightly regulated at the transcriptional, post-transcriptional and post-translational levels (Jishage et al., 1996; Zgurskaya et al., 1997; Kojic & Venturi, 2001; Hengge-Aronis, 2002; Bertani et al., 2003; Schuster et al., 2004; Jovcic et al., 2008). RpoS regulates genes implicated in stress protection and virulence (Loewen et al., 1998; Ishihama, 2000) and, in Pseudomonas, genes involved in niche colonization (Jorgensen et al., 1999; Suh et al., 1999). In P.