Tsrp1 Is a Novel Cyclic Diguanosine Monophosphate Effector that Plays a Role in the Organic-Solvent Tolerance of Rhodococcus ruber.

Abstract

Cyclic diguanosine monophosphate is a ubiquitous second messenger that regulates diverse cellular processes. Rhodococcus ruber SD3 has potential for use in removing environmental pollutants such as phenol and toluene. In this study, Tsrp1 was found to be a novel cyclic diguanosine monophosphate effector in this strain. The interaction between Tsrp1 and c-di-GMP was verified by surface plasmon resonance, and the dissociation constant was 64 ± 6.84 μM. Moreover, in comparison with the wild-type strain, the recombinant R. ruber SD3 strain, which exhibited elevated levels tsrp1 gene expression, demonstrated enhanced growth in the presence of toluene and phenol. Both recombinant R. ruber SD3 and the wild-type strain completely degraded toluene (0.3 g/l, 0.6 g/l and 0.9 g/l) and phenol (0.6 g/l, 0.8 g/l and 1.0 g/l) in 72 h. Furthermore, differential expression of key genes encoding transcription factors was identified based on the transcriptomic comparison between the two strains. This study is the first to describe a novel cyclic diguanosine monophosphate effector and its role in the characteristics of R. ruber SD3, which will shed new light on the mechanisms underlying the organic solvent tolerance of R. ruber SD3.