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Huo L, Ma A, Liu H, Wang X, Song C. Diversity and ecological assembly process of aerobic anoxygenic phototrophic bacteria in a low irradiation area, Three Gorges Reservoir. J Environ Sci (China) 2024; 143:116-125. [PMID: 38644009 DOI: 10.1016/j.jes.2023.08.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 08/09/2023] [Accepted: 08/11/2023] [Indexed: 04/23/2024]
Abstract
Aerobic anoxygenic phototrophic bacteria (AAPB) are significant bacterial groups in aquatic ecosystems, known for their rapid growth and photoheterotrophic characteristics. However, the distribution and ecological assembly process of AAPB in low irradiation freshwater basins remain unclear, warranting further investigation. In this study, we present the diversity, abundance, spatial variations, ecological process, and community interaction of AAPB in sediment of Three Gorges Reservoir (TGR) under low irradiation. Our findings demonstrate the dominant genera of AAPB community that exist in the TGR area also are appeared in different waters, with some regional preference. Moreover, the concentration of pufM gene, an indicator for AAPB, maintains a consistently high numerical level ranging from (2.21 ± 0.44) × 104 to (9.98 ± 0.30) × 107 gene copies/g. Although solar irradiation is suggested as the major factor affecting AAPB, it remains unclear whether and how AAPB differ between regions due to varying solar irradiation levels. Our results show spatial differences between total bacteria and AAPB communities, with significant differences observed only in AAPB. Geographical and environmental factor contributed less than 10% to the spatial difference of community, with sediment type and environmental factors being the key factors influencing microbial community structure. The stochastic process plays a dominant role in the aggregation and replacement of AAPB communities, among which the most contribution is dispersal limitation. For AAPB network, Yoonia and Gemmobacter are the hubs for modules. Those results valuable insights into the AAPB communities in TGR with low irradiation.
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Affiliation(s)
- Lixin Huo
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China; Chongqing School, University of Chinese Academy of Sciences, College of Resources and Environment, Chongqing 400714, China; Key Laboratory of Reservoir Aquatic Environment, Chinese Academy of Sciences, Chongqing 400714, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Anran Ma
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China; Chongqing School, University of Chinese Academy of Sciences, College of Resources and Environment, Chongqing 400714, China; Key Laboratory of Reservoir Aquatic Environment, Chinese Academy of Sciences, Chongqing 400714, China
| | - Hong Liu
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China; Chongqing School, University of Chinese Academy of Sciences, College of Resources and Environment, Chongqing 400714, China; Key Laboratory of Reservoir Aquatic Environment, Chinese Academy of Sciences, Chongqing 400714, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Xingzu Wang
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China; Chongqing School, University of Chinese Academy of Sciences, College of Resources and Environment, Chongqing 400714, China; Key Laboratory of Reservoir Aquatic Environment, Chinese Academy of Sciences, Chongqing 400714, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Cheng Song
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China; Key Laboratory of Reservoir Aquatic Environment, Chinese Academy of Sciences, Chongqing 400714, China
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Liu R, Cai R, Wang M, Zhang J, Zhang H, Li C, Sun C. Metagenomic insights into Heimdallarchaeia clades from the deep-sea cold seep and hydrothermal vent. ENVIRONMENTAL MICROBIOME 2024; 19:43. [PMID: 38909236 PMCID: PMC11193907 DOI: 10.1186/s40793-024-00585-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 06/18/2024] [Indexed: 06/24/2024]
Abstract
Heimdallarchaeia is a class of the Asgardarchaeota, are the most probable candidates for the archaeal protoeukaryote ancestor that have been identified to date. However, little is known about their life habits regardless of their ubiquitous distribution in diverse habitats, which is especially true for Heimdallarchaeia from deep-sea environments. In this study, we obtained 13 metagenome-assembled genomes (MAGs) of Heimdallarchaeia from the deep-sea cold seep and hydrothermal vent. These MAGs belonged to orders o_Heimdallarchaeales and o_JABLTI01, and most of them (9 MAGs) come from the family f_Heimdallarchaeaceae according to genome taxonomy database (GTDB). These are enriched for common eukaryote-specific signatures. Our results show that these Heimdallarchaeia have the metabolic potential to reduce sulfate (assimilatory) and nitrate (dissimilatory) to sulfide and ammonia, respectively, suggesting a previously unappreciated role in biogeochemical cycling. Furthermore, we find that they could perform both TCA and rTCA pathways coupled with pyruvate metabolism for energy conservation, fix CO2 and generate organic compounds through an atypical Wood-Ljungdahl pathway. In addition, many genes closely associated with bacteriochlorophyll and carotenoid biosynthesis, and oxygen-dependent metabolic pathways are identified in these Heimdallarchaeia MAGs, suggesting a potential light-utilization by pigments and microoxic lifestyle. Taken together, our results indicate that Heimdallarchaeia possess a mixotrophic lifestyle, which may give them more flexibility to adapt to the harsh deep-sea conditions.
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Affiliation(s)
- Rui Liu
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao, China
- Center of Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Ruining Cai
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao, China
- Center of Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Minxiao Wang
- Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Center of Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Jing Zhang
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao, China
- Center of Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Huan Zhang
- Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Center of Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Chaolun Li
- Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
- Center of Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China.
| | - Chaomin Sun
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao, China.
- Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
- Center of Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China.
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Cai R, He W, Zhang J, Liu R, Yin Z, Zhang X, Sun C. Blue light promotes zero-valent sulfur production in a deep-sea bacterium. EMBO J 2023; 42:e112514. [PMID: 36946144 PMCID: PMC10267690 DOI: 10.15252/embj.2022112514] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 02/17/2023] [Accepted: 02/28/2023] [Indexed: 03/23/2023] Open
Abstract
Increasing evidence has shown that light exists in a diverse range of deep-sea environments. We unexpectedly found that blue light is necessary to produce excess zero-valent sulfur (ZVS) in Erythrobacter flavus 21-3, a bacterium that has been recently isolated from a deep-sea cold seep. E. flavus 21-3 is able to convert thiosulfate to ZVS using a novel thiosulfate oxidation pathway comprising a thiosulfate dehydrogenase (TsdA) and a thiosulfohydrolase (SoxB). Using proteomic, bacterial two-hybrid and heterologous expression assays, we found that the light-oxygen-voltage histidine kinase LOV-1477 responds to blue light and activates the diguanylate cyclase DGC-2902 to produce c-di-GMP. Subsequently, the PilZ domain-containing protein mPilZ-1753 binds to c-di-GMP and activates TsdA through direct interaction. Finally, Raman spectroscopy and gene knockout results verified that TsdA and two SoxB homologs cooperate to regulate ZVS production. As ZVS is an energy source for E. flavus 21-3, we propose that deep-sea blue light provides E. flavus 21-3 with a selective advantage in the cold seep, suggesting a previously unappreciated relationship between light-sensing pathways and sulfur metabolism in a deep-sea microorganism.
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Affiliation(s)
- Ruining Cai
- CAS Key Laboratory of Experimental Marine Biology & Center of Deep Sea Research, Institute of OceanologyChinese Academy of SciencesQingdaoChina
- Laboratory for Marine Biology and BiotechnologyQingdao National Laboratory for Marine Science and TechnologyQingdaoChina
- College of Earth ScienceUniversity of Chinese Academy of SciencesBeijingChina
- Center of Ocean Mega‐ScienceChinese Academy of SciencesQingdaoChina
| | - Wanying He
- College of Earth ScienceUniversity of Chinese Academy of SciencesBeijingChina
- Center of Ocean Mega‐ScienceChinese Academy of SciencesQingdaoChina
- CAS Key Laboratory of Marine Geology and Environment & Center of Deep Sea Research, Institute of OceanologyChinese Academy of SciencesQingdaoChina
| | - Jing Zhang
- School of Life SciencesHebei UniversityBaodingChina
| | - Rui Liu
- CAS Key Laboratory of Experimental Marine Biology & Center of Deep Sea Research, Institute of OceanologyChinese Academy of SciencesQingdaoChina
- Laboratory for Marine Biology and BiotechnologyQingdao National Laboratory for Marine Science and TechnologyQingdaoChina
- Center of Ocean Mega‐ScienceChinese Academy of SciencesQingdaoChina
| | - Ziyu Yin
- College of Earth ScienceUniversity of Chinese Academy of SciencesBeijingChina
- Center of Ocean Mega‐ScienceChinese Academy of SciencesQingdaoChina
- CAS Key Laboratory of Marine Geology and Environment & Center of Deep Sea Research, Institute of OceanologyChinese Academy of SciencesQingdaoChina
| | - Xin Zhang
- College of Earth ScienceUniversity of Chinese Academy of SciencesBeijingChina
- Center of Ocean Mega‐ScienceChinese Academy of SciencesQingdaoChina
- CAS Key Laboratory of Marine Geology and Environment & Center of Deep Sea Research, Institute of OceanologyChinese Academy of SciencesQingdaoChina
| | - Chaomin Sun
- CAS Key Laboratory of Experimental Marine Biology & Center of Deep Sea Research, Institute of OceanologyChinese Academy of SciencesQingdaoChina
- Laboratory for Marine Biology and BiotechnologyQingdao National Laboratory for Marine Science and TechnologyQingdaoChina
- College of Earth ScienceUniversity of Chinese Academy of SciencesBeijingChina
- Center of Ocean Mega‐ScienceChinese Academy of SciencesQingdaoChina
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Zhu Z, Wu Y, Hu W, Zheng X, Chen Y. Valorization of food waste fermentation liquid into single cell protein by photosynthetic bacteria via stimulating carbon metabolic pathway and environmental behaviour. BIORESOURCE TECHNOLOGY 2022; 361:127704. [PMID: 35908636 DOI: 10.1016/j.biortech.2022.127704] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Revised: 07/20/2022] [Accepted: 07/22/2022] [Indexed: 06/15/2023]
Abstract
Single cell protein (SCP) production by photosynthetic bacteria (PSB) is dependent on the bioavailability of carbon source, while sufficient volatile fatty acids (VFAs) in food waste fermentation liquid might be a potential alternative. It is unclear how the fermentation liquid affects the SCP biosynthesis and the related metabolic mechanism. This work demonstrated that the SCP production could be improved effectively (2088.4 mg/L) with high conversion capacity of carbon source (0.99 mg-biomass/mg-COD) by regulating carbon source level. PSB preferred to utilize the VFAs in food waste fermentation liquid. The carbon metabolic pathways (e.g., the transformation of VFAs to acetyl-CoA, and tricarboxylic acid cycle) involved in the SCP production were enhanced under optimal condition. Moreover, optimal carbon source regulation could significantly stimulate the environmental behaviour of PSB (e.g., two-component system, quorum sensing, and ATP-binding cassette transporter) involved in adaptation to external stimulus and maintaining high bacterial activity, resulting in SCP yield promotion.
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Affiliation(s)
- Zizeng Zhu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Yang Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Wanying Hu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Xiong Zheng
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
| | - Yinguang Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
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Wang Y, Bi HY, Chen HG, Zheng PF, Zhou YL, Li JT. Metagenomics Reveals Dominant Unusual Sulfur Oxidizers Inhabiting Active Hydrothermal Chimneys From the Southwest Indian Ridge. Front Microbiol 2022; 13:861795. [PMID: 35694283 PMCID: PMC9174799 DOI: 10.3389/fmicb.2022.861795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 04/12/2022] [Indexed: 11/25/2022] Open
Abstract
The deep-sea hydrothermal vents (DSHVs) in the Southwest Indian Ridge (SWIR) are formed by specific geological settings. However, the community structure and ecological function of the microbial inhabitants on the sulfide chimneys of active hydrothermal vents remain largely unknown. In this study, our analyses of 16S rRNA gene amplicons and 16S rRNA metagenomic reads showed the dominance of sulfur-oxidizing Ectothiorhodospiraceae, Thiomicrorhabdus, Sulfurimonas, and Sulfurovum on the wall of two active hydrothermal chimneys. Compared with the inactive hydrothermal sediments of SWIR, the active hydrothermal chimneys lacked sulfur-reducing bacteria. The metabolic potentials of the retrieved 82 metagenome-assembled genomes (MAGs) suggest that sulfur oxidation might be conducted by Thiohalomonadales (classified as Ectothiorhodospiraceae based on 16S rRNA gene amplicons), Sulfurovaceae, Hyphomicrobiaceae, Thiotrichaceae, Thiomicrospiraceae, and Rhodobacteraceae. For CO2 fixation, the Calvin-Benson-Bassham and reductive TCA pathways were employed by these bacteria. In Thiohalomonadales MAGs, we revealed putative phytochrome, carotenoid precursor, and squalene synthesis pathways, indicating a possible capacity of Thiohalomonadales in adaptation to dynamics redox conditions and the utilization of red light from the hot hydrothermal chimneys for photolithotrophic growth. This study, therefore, reveals unique microbiomes and their genomic features in the active hydrothermal chimneys of SWIR, which casts light on ecosystem establishment and development in hydrothermal fields and the deep biosphere.
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Affiliation(s)
- Yong Wang
- Institute for Marine Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen, China
- *Correspondence: Yong Wang,
| | - Hong-Yu Bi
- Institute of Deep Sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
| | - Hua-Guan Chen
- Institute of Deep Sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
- College of Marine Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Peng-Fei Zheng
- Institute of Deep Sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
| | - Ying-Li Zhou
- Institute of Deep Sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
- College of Marine Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Jiang-Tao Li
- State Key Laboratory of Marine Geology, Tongji University, Shanghai, China
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Xu N, Zhao Q, Zhang Z, Zhang Q, Wang Y, Qin G, Ke M, Qiu D, Peijnenburg WJGM, Lu T, Qian H. Phyllosphere Microorganisms: Sources, Drivers, and Their Interactions with Plant Hosts. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:4860-4870. [PMID: 35435673 DOI: 10.1021/acs.jafc.2c01113] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The leaves of plants are colonized by various microorganisms. In comparison to the rhizosphere, less is known about the characteristics and ecological functions of phyllosphere microorganisms. Phyllosphere microorganisms mainly originate from soil, air, and seeds. The composition of phyllosphere microorganisms is mainly affected by ecological and abiotic factors. Phyllosphere microorganisms execute multiple ecological functions by influencing leaf functions and longevity, seed mass, fruit development, and homeostasis of host growth. A plant can respond to phyllosphere microorganisms by secondary metabolite secretion and its immune system. Meanwhile, phyllosphere microorganisms play an important role in ecological stability and environmental safety assessment. However, as a result of the instability of the phyllosphere environment and the poor cultivability of phyllosphere microorganisms in the current research, there are still many limitations, such as the lack of insight into the mechanisms of plant-microorganism interactions, the roles of phyllosphere microorganisms in plant growth processes, the responses of phyllosphere microorganisms to plant metabolites, etc. This review summarizes the latest progress made in the research of the phyllosphere in recent years. This is beneficial for deepening our understanding of phyllosphere microorganisms and promoting the research of plant-atmosphere interactions, plant pathogens, and plant biological control.
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Affiliation(s)
- Nuohan Xu
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, People's Republic of China
| | - Qianqiu Zhao
- Xinjiang Institute of Ecology and Geography, Chinese Academy of Science, Urumqi, Xinjiang 830011, People's Republic of China
| | - Zhenyan Zhang
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, People's Republic of China
| | - Qi Zhang
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, People's Republic of China
| | - Yan Wang
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, People's Republic of China
| | - Guoyan Qin
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, People's Republic of China
| | - Mingjing Ke
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, People's Republic of China
| | - Danyan Qiu
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, People's Republic of China
| | - W J G M Peijnenburg
- Institute of Environmental Sciences (CML), Leiden University, 2300 RA Leiden, Netherlands
- National Institute of Public Health and the Environment (RIVM), Center for Safety of Substances and Products, Post Office Box 1, 3720 BA Bilthoven, Netherlands
| | - Tao Lu
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, People's Republic of China
| | - Haifeng Qian
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, People's Republic of China
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Characterization of the First Cultured Representative of " Candidatus Thermofonsia" Clade 2 within Chloroflexi Reveals Its Phototrophic Lifestyle. mBio 2022; 13:e0028722. [PMID: 35229635 PMCID: PMC8941918 DOI: 10.1128/mbio.00287-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
“Candidatus Thermofonsia” represents a novel class within the phylum Chloroflexi. Metagenomic analysis reveals “Ca. Thermofonsia” harbors phototrophs outside the classically phototrophic Chloroflexia class. Unfortunately, the paucity of pure cultures limits further insights into their potential phototrophy. Here, we report the successful isolation of a “Ca. Thermofonsia” representative (Phototrophicus methaneseepsis ZRK33) from a deep-sea cold seep. Using combined physiological, genomic, and transcriptomic methods, we further show the long-wavelength light (e.g., red and infrared light) could promote the growth of strain ZRK33 and upregulate the expression of genes associated with phototrophy. In particular, strain ZRK33 has a typical phototrophic lifestyle under both laboratory and deep-sea conditions. Strain ZRK33 also possesses the ability to fix inorganic carbon through the 3-hydroxypropionate bicycle in both laboratory and deep-sea in situ environments, and the combined autotrophic, phototrophic, and heterotrophic capabilities endow strain ZRK33 with a photomixotrophic lifestyle. Notably, the predicted genes associated with phototrophy broadly exist in the metagenomes of 27 deep-sea Chloroflexi members, strongly suggesting diverse phototrophic Chloroflexi members are distributed in various unexplored deep biospheres.
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Abstract
Light is a ubiquitous energy source and environmental signal that broadly impacts the lifestyle of a large number of photosynthetic/nonphotosynthetic microorganisms living in the euphotic layer. However, the responses of deep-sea microbes to light are largely unknown, even though blue light is proposed to be distributed in the deep ocean. Here, we successfully cultured a novel bacterial species, named Spongiibacter nanhainus CSC3.9, from deep-sea cold seep samples by a blue light induction approach. The growth of strain CSC3.9 was obviously promoted by the illumination of blue light. We next determined BLUF (a typical blue light photoreceptor) was the most essential factor directing light sensing of strain CSC3.9 through a combined proteomic and genetic method. The function of light sensing mediated by BLUF was further confirmed by the in vitro-synthesized protein. Notably, homologs of BLUF widely existed across the marine microorganisms (containing Spongiibacter species) derived from different environments, including cold seeps. This strongly indicates that the distribution of light utilization by the nonphototrophic bacteria living in the ocean is broad and has been substantially underestimated. IMPORTANCE Extensive studies have been conducted to explore the mechanisms of light sensing and utilization by microorganisms that live in the photic zone. Strikingly, accumulated evidence shows that light is distributed in the deep biosphere. However, the existence and process of light sensing and utilization by microbes inhabiting the deep ocean have been seldom reported. In the present study, a novel bacterial strain, Spongiibacter nanhainus CSC3.9, was enriched and purified from a deep-sea cold seep sample through a blue light induction method. Combined with genomic, proteomic, genetic, and biochemical approaches, the mechanism of this novel strain sensing blue light through a BLUF-dependent pathway was detailed. Our study provides a good model to study the mechanisms of light sensing mediated by deep-sea nonphototrophic bacteria.
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Bioluminescence and Photoreception in Unicellular Organisms: Light-Signalling in a Bio-Communication Perspective. Int J Mol Sci 2021; 22:ijms222111311. [PMID: 34768741 PMCID: PMC8582858 DOI: 10.3390/ijms222111311] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 10/12/2021] [Accepted: 10/13/2021] [Indexed: 12/13/2022] Open
Abstract
Bioluminescence, the emission of light catalysed by luciferases, has evolved in many taxa from bacteria to vertebrates and is predominant in the marine environment. It is now well established that in animals possessing a nervous system capable of integrating light stimuli, bioluminescence triggers various behavioural responses and plays a role in intra- or interspecific visual communication. The function of light emission in unicellular organisms is less clear and it is currently thought that it has evolved in an ecological framework, to be perceived by visual animals. For example, while it is thought that bioluminescence allows bacteria to be ingested by zooplankton or fish, providing them with favourable conditions for growth and dispersal, the luminous flashes emitted by dinoflagellates may have evolved as an anti-predation system against copepods. In this short review, we re-examine this paradigm in light of recent findings in microorganism photoreception, signal integration and complex behaviours. Numerous studies show that on the one hand, bacteria and protists, whether autotrophs or heterotrophs, possess a variety of photoreceptors capable of perceiving and integrating light stimuli of different wavelengths. Single-cell light-perception produces responses ranging from phototaxis to more complex behaviours. On the other hand, there is growing evidence that unicellular prokaryotes and eukaryotes can perform complex tasks ranging from habituation and decision-making to associative learning, despite lacking a nervous system. Here, we focus our analysis on two taxa, bacteria and dinoflagellates, whose bioluminescence is well studied. We propose the hypothesis that similar to visual animals, the interplay between light-emission and reception could play multiple roles in intra- and interspecific communication and participate in complex behaviour in the unicellular world.
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