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Lang-Yona N, Maier S, Macholdt DS, Müller-Germann I, Yordanova P, Rodriguez-Caballero E, Jochum KP, Al-Amri A, Andreae MO, Fröhlich-Nowoisky J, Weber B. Insights into microbial involvement in desert varnish formation retrieved from metagenomic analysis. ENVIRONMENTAL MICROBIOLOGY REPORTS 2018; 10:264-271. [PMID: 29488349 DOI: 10.1111/1758-2229.12634] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 02/19/2018] [Indexed: 06/08/2023]
Abstract
Desert varnishes are dark rock coatings observed in arid environments and might resemble Mn-rich coatings found on Martian rocks. Their formation mechanism is not fully understood and the possible microbial involvement is under debate. In this study, we applied DNA metagenomic Shotgun sequencing of varnish and surrounding soil to evaluate the composition of the microbial community and its potential metabolic function. We found that the α diversity was lower in varnish compared to soil samples (p value < 0.05), suggesting distinct populations with significantly higher abundance of Actinobacteria, Proteobacteria and Cyanobacteria within the varnish. Additionally, we observed increased levels of transition metal metabolic processes in varnish compared to soil samples. Nevertheless, potentially relevant enzymes for varnish formation were detected at low to insignificant levels in both niches, indicating no current direct microbial involvement in Mn oxidation. This finding is supported by quantitative genomic analysis, elemental analysis, fluorescence imaging and scanning transmission X-ray microscopy. We thus conclude that the distinct microbial communities detected in desert varnish originate from settled Aeolian microbes, which colonized this nutrient-enriched niche, and discuss possible indirect contributions of microorganisms to the formation of desert varnish.
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Affiliation(s)
- Naama Lang-Yona
- Multiphase Chemistry Department, Hahn-Meitner-Weg 1, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Stefanie Maier
- Multiphase Chemistry Department, Hahn-Meitner-Weg 1, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Dorothea S Macholdt
- Biogeochemistry Department, Hahn-Meitner-Weg 1, Max Planck Institute for Chemistry, 55128 Mainz, Germany
- Climate Geochemistry Department, Hahn-Meitner-Weg 1, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Isabell Müller-Germann
- Multiphase Chemistry Department, Hahn-Meitner-Weg 1, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Petya Yordanova
- Multiphase Chemistry Department, Hahn-Meitner-Weg 1, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Emilio Rodriguez-Caballero
- Multiphase Chemistry Department, Hahn-Meitner-Weg 1, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Klaus P Jochum
- Climate Geochemistry Department, Hahn-Meitner-Weg 1, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Abdullah Al-Amri
- Geology and Geophysics Department, King Saud University, PO Box 2455, Riyadh 11451, Saudi Arabia
| | - Meinrat O Andreae
- Biogeochemistry Department, Hahn-Meitner-Weg 1, Max Planck Institute for Chemistry, 55128 Mainz, Germany
- Geology and Geophysics Department, King Saud University, PO Box 2455, Riyadh 11451, Saudi Arabia
| | - Janine Fröhlich-Nowoisky
- Multiphase Chemistry Department, Hahn-Meitner-Weg 1, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Bettina Weber
- Multiphase Chemistry Department, Hahn-Meitner-Weg 1, Max Planck Institute for Chemistry, 55128 Mainz, Germany
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Selikhanov GK, Fando MS, Dontsova MV, Gabdulkhakov AG. Investigations of Photosensitive Proteins by Serial Crystallography. BIOCHEMISTRY (MOSCOW) 2018; 83:S163-S175. [DOI: 10.1134/s0006297918140134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Cyanobacterial Metabolite Calothrixins: Recent Advances in Synthesis and Biological Evaluation. Mar Drugs 2016; 14:17. [PMID: 26771620 PMCID: PMC4728514 DOI: 10.3390/md14010017] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 12/22/2015] [Accepted: 01/04/2016] [Indexed: 12/30/2022] Open
Abstract
The marine environment is host to unparalleled biological and chemical diversity, making it an attractive resource for the discovery of new therapeutics for a plethora of diseases. Compounds that are extracted from cyanobacteria are of special interest due to their unique structural scaffolds and capacity to produce potent pharmaceutical and biotechnological traits. Calothrixins A and B are two cyanobacterial metabolites with a structural assembly of quinoline, quinone, and indole pharmacophores. This review surveys recent advances in the synthesis and evaluation of the biological activities of calothrixins. Due to the low isolation yields from the marine source and the promise this scaffold holds for anticancer and antimicrobial drugs, organic and medicinal chemists around the world have embarked on developing efficient synthetic routes to produce calothrixins. Since the first review appeared in 2009, 11 novel syntheses of calothrixins have been published in the efforts to develop methods that contain fewer steps and higher-yielding reactions. Calothrixins have shown their potential as topoisomerase I poisons for their cytotoxicity in cancer. They have also been observed to target various aspects of RNA synthesis in bacteria. Further investigation into the exact mechanism for their bioactivity is still required for many of its analogs.
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