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Transcriptomic and proteomic insight into the mechanism of cyclooctasulfur‐ versus thiosulfate‐oxidation by the chemolithoautotroph Sulfurimonas denitrificans
- Götz, Florian, Pjevac, Petra, Markert, Stephanie, McNichol, Jesse, Becher, Dörte, Schweder, Thomas, Mussmann, Marc, Sievert, Stefan M.
- Environmental microbiology 2019 v.21 no.1 pp. 244-258
- bacteria, metabolism, models, multigene family, oxidation, proteins, proteome, proteomics, sulfur, thiosulfates, transcriptome, transcriptomics
- Chemoautotrophic bacteria belonging to the genus Sulfurimonas (class Campylobacteria) were previously identified as key players in the turnover of zero‐valence sulfur, a central intermediate in the marine sulfur cycle. S. denitrificans was further shown to be able to oxidize cyclooctasulfur (S₈). However, at present the mechanism of activation and metabolism of cyclooctasulfur is not known. Here, we assessed the transcriptome and proteome of S. denitrificans grown with either thiosulfate or S₈ as the electron donor. While the overall expression profiles under the two growth conditions were rather similar, distinct differences were observed that could be attributed to the utilization of S₈. This included a higher abundance of expressed genes related to surface attachment in the presence of S₈, and the differential regulation of the sulfur‐oxidation multienzyme complex (SOX), which in S. denitrificans is encoded in two gene clusters: soxABXY ₁Z ₁ and soxCDY ₂Z ₂. While the proteins of both clusters were present with thiosulfate, only proteins of the soxCDY ₂Z ₂ were detected at significant levels with S₈. Based on these findings a model for the oxidation of S₈ is proposed. Our results have implications for interpreting metatranscriptomic and ‐proteomic data and for the observed high level of diversification of soxY ₂Z ₂ among sulfur‐oxidizing Campylobacteria.