Gemmatimonas groenlandica sp. nov. Is an Aerobic Anoxygenic Phototroph in the Phylum Gemmatimonadetes

• Published in: Frontiers in Microbiology
• Main Authors: Yonghui Zeng, Nupur, Naicheng Wu, Anne Mette Madsen, Xihan Chen, Alastair T. Gardiner, Michal Koblížek
• Format: Article in Journal/Newspaper
• Language: English
• Published: Frontiers Media S.A. 2021
• Subjects: MALDI-TOF MS; bacterial isolation; phototrophy; Gemmatimonadetes; oligotrophic environment; Microbiology; QR1-502; Arctic; Greenland; glacier; Zackenberg
• Online Access: https://doi.org/10.3389/fmicb.2020.606612; https://doaj.org/article/3289509704324a039f14174681bbf659

The bacterial phylum Gemmatimonadetes contains members capable of performing bacteriochlorophyll-based phototrophy (chlorophototrophy). However, only one strain of chlorophototrophic Gemmatimonadetes bacteria (CGB) has been isolated to date, hampering our further understanding of their photoheterotrophic lifestyle and the evolution of phototrophy in CGB. By combining a culturomics strategy with a rapid screening technique for chlorophototrophs, we report the isolation of a new member of CGB, Gemmatimonas (G.) groenlandica sp. nov., from the surface water of a stream in the Zackenberg Valley in High Arctic Greenland. Distinct from the microaerophilic G. phototrophica strain AP64T, G. groenlandica strain TET16T is a strictly aerobic anoxygenic phototroph, lacking many oxygen-independent enzymes while possessing an expanded arsenal for coping with oxidative stresses. Its pigment composition and infra-red absorption properties are also different from G. phototrophica, indicating that it possesses a different photosystem apparatus. The complete genome sequence of G. groenlandica reveals unique and conserved features in the photosynthesis gene clusters of CGB. We further analyzed metagenome-assembled genomes of CGB obtained from soil and glacier metagenomes from Northeast Greenland, revealing a wide distribution pattern of CGB beyond the stream water investigated.