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Marton Menendez A, Nesbitt DJ. Thermodynamic compensation to temperature extremes in B. subtilis vs T. maritima lysine riboswitches. Biophys J 2024:S0006-3495(24)00516-2. [PMID: 39091026 DOI: 10.1016/j.bpj.2024.07.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 06/17/2024] [Accepted: 07/29/2024] [Indexed: 08/04/2024] Open
Abstract
T. maritima and B. subtilis are bacteria that inhabit significantly different thermal environments, ∼80 vs. ∼40°C, yet employ similar lysine riboswitches to aid in the transcriptional regulation of the genes involved in the synthesis and transport of amino acids. Despite notable differences in G-C basepair frequency and primary sequence, the aptamer moieties of each riboswitch have striking similarities in tertiary structure, with several conserved motifs and long-range interactions. To explore genetic adaptation in extreme thermal environments, we compare the kinetic and thermodynamic behaviors in T. maritima and B. subtilis lysine riboswitches via single-molecule fluorescence resonance energy transfer analysis. Kinetic studies reveal that riboswitch folding rates increase with lysine concentration while the unfolding rates are independent of lysine. This indicates that both riboswitches bind lysine through an induced-fit ("bind-then-fold") mechanism, with lysine binding necessarily preceding conformational changes. Temperature-dependent van't Hoff studies reveal qualitative similarities in the thermodynamic landscapes for both riboswitches in which progression from the open, lysine-unbound state to both transition states (‡) and closed, lysine-bound conformations is enthalpically favored yet entropically penalized, with comparisons of enthalpic and entropic contributions extrapolated to a common [K+] = 100 mM in quantitative agreement. Finally, temperature-dependent Eyring analysis reveals the TMA and BSU riboswitches to have remarkably similar folding/unfolding rate constants when extrapolated to their respective (40 and 80°C) environmental temperatures. Such behavior suggests a shared strategy for ligand binding and aptamer conformational change in the two riboswitches, based on thermodynamic adaptations in number of G-C basepairs and/or modifications in tertiary structure that stabilize the ligand-unbound conformation to achieve biocompetence under both hyperthermophilic and mesothermophilic conditions.
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Affiliation(s)
- Andrea Marton Menendez
- JILA, University of Colorado Boulder and National Institute of Standards and Technology, Boulder, Colorado; Department of Chemistry, University of Colorado Boulder, Boulder, Colorado.
| | - David J Nesbitt
- JILA, University of Colorado Boulder and National Institute of Standards and Technology, Boulder, Colorado; Department of Chemistry, University of Colorado Boulder, Boulder, Colorado; Department of Physics, University of Colorado Boulder, Boulder, Colorado.
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Zhang Z, Liu T, Li X, Ye Q, Bangash HI, Zheng J, Peng N. Metagenome-assembled genomes reveal carbohydrate degradation and element metabolism of microorganisms inhabiting Tengchong hot springs, China. ENVIRONMENTAL RESEARCH 2023; 238:117144. [PMID: 37716381 DOI: 10.1016/j.envres.2023.117144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/31/2023] [Accepted: 09/13/2023] [Indexed: 09/18/2023]
Abstract
A hot spring is a distinctive aquatic environment that provides an excellent system to investigate microorganisms and their function in elemental cycling processes. Previous studies of terrestrial hot springs have been mostly focused on the microbial community, one special phylum or category, or genes involved in a particular metabolic step, while little is known about the overall functional metabolic profiles of microorganisms inhabiting the terrestrial hot springs. Here, we analyzed the microbial community structure and their functional genes based on metagenomic sequencing of six selected hot springs with different temperature and pH conditions. We sequenced a total of 11 samples from six hot springs and constructed 162 metagenome-assembled genomes (MAGs) with completeness above 70% and contamination lower than 10%. Crenarchaeota, Euryarchaeota and Aquificae were found to be the dominant phyla. Functional annotation revealed that bacteria encode versatile carbohydrate-active enzymes (CAZYmes) for the degradation of complex polysaccharides, while archaea tend to assimilate C1 compounds through carbon fixation. Under nitrogen-deficient conditions, there were correspondingly fewer genes involved in nitrogen metabolism, while abundant and diverse set of genes participating in sulfur metabolism, particularly those associated with sulfide oxidation and thiosulfate disproportionation. In summary, archaea and bacteria residing in the hot springs display distinct carbon metabolism fate, while sharing the common energy preference through sulfur metabolism. Overall, this research contributes to a better comprehension of biogeochemistry of terrestrial hot springs.
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Affiliation(s)
- Zhufeng Zhang
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China
| | - Tao Liu
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China.
| | - Xudong Li
- State Key Laboratory of Agricultural Microbiology, Hubei Key Laboratory of Agricultural Bioinformatics, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China
| | - Qing Ye
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China
| | - Hina Iqbal Bangash
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China
| | - Jinshui Zheng
- State Key Laboratory of Agricultural Microbiology, Hubei Key Laboratory of Agricultural Bioinformatics, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China
| | - Nan Peng
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China.
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Li C, Miao L, Adyel TM, Huang W, Wang J, Wu J, Hou J, Wang Z. Eukaryotes contribute more than bacteria to the recovery of freshwater ecosystem functions under different drought durations. Environ Microbiol 2023. [PMID: 36916068 DOI: 10.1111/1462-2920.16370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 03/10/2023] [Indexed: 03/16/2023]
Abstract
Global climate change mostly impacts river ecosystems by affecting microbial biodiversity and ecological functions. Considering the high functional redundancy of microorganisms, the unknown relationship between biodiversity and ecosystem functions obstructs river ecological research, especially under the influence of increasing weather extremes, such as in intermittent rivers and ephemeral streams (IRES). Herein, dry-wet alternation experiments were conducted in artificial stream channels for 25 and 90 days of drought, both followed by 20 days of rewetting. The dynamic recovery of microbial biodiversity and ecosystem functions (represented by ecosystem metabolism and denitrification rate) were determined to analyse biodiversity-ecosystem-function (BEF) relationships after different drought durations. There was a significant difference between bacterial and eukaryotic biodiversity recovery after drought. Eukaryotic biodiversity was more sensitive to drought duration than bacterial, and the eukaryotic network was more stable under dry-wet alternations. Based on the establishment of partial least squares path models, we found that eukaryotic biodiversity has a stronger effect on ecosystem functions than bacteria after long-term drought. Indeed, this work represents a significant step forward for further research on the ecosystem functions of IRES, especially emphasizing the importance of eukaryotic biodiversity in the BEF relationship.
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Affiliation(s)
- Chaoran Li
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, 210098, Nanjing, People's Republic of China
| | - Lingzhan Miao
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, 210098, Nanjing, People's Republic of China
| | - Tanveer M Adyel
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Melbourne, Victoria, Australia
- STEM, University of South Australia, Mawson Lakes Campus, 5095, Mawson, Australia
| | - Wei Huang
- China Institute of Water Resources and Hydropower Research, 100038, Beijing, People's Republic of China
| | - Jianjun Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, China
| | - Jun Wu
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, 210098, Nanjing, People's Republic of China
| | - Jun Hou
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, 210098, Nanjing, People's Republic of China
| | - Zhiyuan Wang
- Center for Eco-Environmental Research, Nanjing Hydraulic Research Institute, National Energy Administration, Ministry of Transport, Ministry of Water Resources, 210029, Nanjing, China
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Van Etten J, Cho CH, Yoon HS, Bhattacharya D. Extremophilic red algae as models for understanding adaptation to hostile environments and the evolution of eukaryotic life on the early earth. Semin Cell Dev Biol 2023; 134:4-13. [PMID: 35339358 DOI: 10.1016/j.semcdb.2022.03.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 02/20/2022] [Accepted: 03/04/2022] [Indexed: 01/08/2023]
Abstract
Extremophiles have always garnered great interest because of their exotic lifestyles and ability to thrive at the physical limits of life. In hot springs environments, the Cyanidiophyceae red algae are the only photosynthetic eukaryotes able to live under extremely low pH (0-5) and relatively high temperature (35ºC to 63ºC). These extremophiles live as biofilms in the springs, inhabit acid soils near the hot springs, and form endolithic populations in the surrounding rocks. Cyanidiophyceae represent a remarkable source of knowledge about the evolution of extremophilic lifestyles and their genomes encode specialized enzymes that have applied uses. Here we review the evolutionary origin, taxonomy, genome biology, industrial applications, and use of Cyanidiophyceae as genetic models. Currently, Cyanidiophyceae comprise a single order (Cyanidiales), three families, four genera, and nine species, including the well-known Cyanidioschyzon merolae and Galdieria sulphuraria. These algae have small, gene-rich genomes that are analogous to those of prokaryotes they live and compete with. There are few spliceosomal introns and evidence exists for horizontal gene transfer as a driver of local adaptation to gain access to external fixed carbon and to extrude toxic metals. Cyanidiophyceae offer a variety of commercial opportunities such as phytoremediation to detoxify contaminated soils or waters and exploitation of their mixotrophic lifestyles to support the efficient production of bioproducts such as phycocyanin and floridosides. In terms of exobiology, Cyanidiophyceae are an ideal model system for understanding the evolutionary effects of foreign gene acquisition and the interactions between different organisms inhabiting the same harsh environment on the early Earth. Finally, we describe ongoing research with C. merolae genetics and summarize the unique insights they offer to the understanding of algal biology and evolution.
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Affiliation(s)
- Julia Van Etten
- Graduate Program in Ecology and Evolution, Rutgers University, New Brunswick, NJ 08901, USA.
| | - Chung Hyun Cho
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, South Korea.
| | - Hwan Su Yoon
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, South Korea.
| | - Debashish Bhattacharya
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ 08901, USA.
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Liu Q, Yang LL, Xin YH. Diversity of the genus Cryobacterium and proposal of 19 novel species isolated from glaciers. Front Microbiol 2023; 14:1115168. [PMID: 37020720 PMCID: PMC10067761 DOI: 10.3389/fmicb.2023.1115168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Accepted: 02/27/2023] [Indexed: 04/07/2023] Open
Abstract
The bacterial genus Cryobacterium includes at present 14 species that live in cryospheric environments. In this study, we analyzed 101 genomes of Cryobacterium with pure cultures obtained from GenBank. They could be classified into 44 species based on average nucleotide identity (ANI) analysis, showing the diversity of Cryobacterium. Among these, 19 strains in our laboratory were isolated from the glacier samples in China. The pairwise ANI values of these 19 strains and known species were <95%, indicating that they represented 19 novel species. The comparative genomic analysis showed significant differences in gene content between the two groups with a maximum growth temperature (T max) of ≤ 20°C and a T max of >20°C. A comprehensive and robust phylogenetic tree, including 14 known species and 19 novel species, was constructed and showed five phylogenetic branches based on 265 concatenated single-copy gene sequences. The T max parameter had a strong phylogenetic signal, indicating that the temperature adaptation of Cryobacterium was largely through vertical transfer rather than horizontal gene transfer and was affected by selection. Furthermore, using polyphasic taxonomy combined with phylogenomic analysis, we proposed 19 novel species of the genus Cryobacterium by the following 19 names: Cryobacterium serini sp. nov., Cryobacterium lactosi sp. nov., Cryobacterium gelidum sp. nov., Cryobacterium suzukii sp. nov., Cryobacterium fucosi sp. nov., Cryobacterium frigoriphilum sp. nov., Cryobacterium cryoconiti sp. nov., Cryobacterium lyxosi sp. nov., Cryobacterium sinapicolor sp. nov., Cryobacterium sandaracinum sp. nov., Cryobacterium cheniae sp. nov., Cryobacterium shii sp. nov., Cryobacterium glucosi sp. nov., Cryobacterium algoritolerans sp. nov., Cryobacterium mannosilyticum sp. nov., Cryobacterium adonitolivorans sp. nov., Cryobacterium algoricola sp. nov., Cryobacterium tagatosivorans sp. nov., and Cryobacterium glaciale sp. nov. Overall, the taxonomy and genomic analysis can improve our knowledge of phenotypic diversity, genetic diversity, and evolutionary characteristics of Cryobacterium.
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