Journal article

Publication year: 2020

Journal: Microorganisms

Volume number: 8

Issue number: 2

Open access status: Gold

DOI Link: https://doi.org/10.3390/microorganisms8020283

Publisher: MDPI

Abstract: 
Photosynthetic bacteria have to deal with the risk of photooxidative stress that occurs in presence of light and oxygen due to the photosensitizing activity of (bacterio-) chlorophylls. Facultative phototrophs of the genus Rhodobacter adapt the formation of photosynthetic complexes to oxygen and light conditions, but cannot completely avoid this stress if environmental conditions suddenly change. R. capsulatus has a stronger pigmentation and faster switches to phototrophic growth than R. sphaeroides. However, its photooxidative stress response has not been investigated. Here, we compare both species by transcriptomics and proteomics, revealing that proteins involved in oxidation reduction processes, DNA, and protein damage repair play pivotal roles. These functions are likely universal to many phototrophs. Furthermore, the alternative sigma factors RpoE and RpoH(II) are induced in both species, even though the genetic localization of the rpoE gene, the RpoE protein itself, and probably its regulon, are different. Despite sharing the same habitats, our findings also suggest individual strategies. The crtlB-tspO operon, encoding proteins for biosynthesis of carotenoid precursors and a regulator of photosynthesis, and cbiX, encoding a putative ferrochelatase, are induced in R. capsulatus. This specific response might support adaptation by maintaining high carotenoid-to-bacteriochlorophyll ratios and preventing the accumulation of porphyrin-derived photosensitizers.

Harvard Citation style: Licht, M., Nuss, A., Volk, M., Konzer, A., Beckstette, M., Berghoff, B., et al. (2020) Adaptation to Photooxidative Stress: Common and Special Strategies of the Alphaproteobacteria Rhodobacter sphaeroides and Rhodobacter capsulatus, Microorganisms, 8(2), Article 283. https://doi.org/10.3390/microorganisms8020283

APA Citation style: Licht, M., Nuss, A., Volk, M., Konzer, A., Beckstette, M., Berghoff, B., & Klug, G. (2020). Adaptation to Photooxidative Stress: Common and Special Strategies of the Alphaproteobacteria Rhodobacter sphaeroides and Rhodobacter capsulatus. Microorganisms. 8(2), Article 283. https://doi.org/10.3390/microorganisms8020283