Corrigendum: Why quorum sensing controls private goods [Front. Microbiol, 8, (2017) (885)] doi: 10.3389/fmicb.2017.00885

Abstract

Here we intend to clarify the function of rbsD, a conserved gene involved in bacterial ribose utilization. As stated in the original article, rbsD is absent in P. aeruginosa, which is the likely cause for its slow growth rate on adenosine as a carbon source. Adenosine is cleaved into ribose and adenine by a periplasmic, quorum sensing-dependent nucleoside hydrolase (Nuh). In the section "The case of Nuh," we suggested that rbsD contributes to ribose uptake, based on the original characterization of an rbsD mutant in E. coli (Oh et al., 1999). However, subsequent biochemical studies have revealed a more specific function. E. coli rbsD encodes a ribose mutarotase that catalyzes the conversion between the pyranose and furanose forms of D-ribose immediately after cytoplasmic uptake by the ribose transporter RbsABC (Kim et al., 2003; Ryu et al., 2004). While ribose primarily exists as a pyranose in solution, the furanose is the preferred substrate in the ensuing phosphorylation by the ribokinase RbsK (Sigrell et al., 1998). Thus, the intracellular level of the furanose as a substrate for RbsK may be the growth-limiting factor in rbsD-deficient P. aeruginosa. Irrespective of these biochemical details, however, our main conclusions drawn in the original article remain the same: Adenosine is a relevant nitrogen but not carbon source in the ecology of P. aeruginosa. As a carbon source, adenosine does not constrain cheating in native P. aeruginosa but rather promotes non-social adaptation during long-term cultivation.