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Chen DD, Fang BZ, Manzoor A, Liu YH, Li L, Mohamad OAA, Shu WS, Li WJ. Revealing the salinity adaptation mechanism in halotolerant bacterium Egicoccus halophilus EGI 80432 T by physiological analysis and comparative transcriptomics. Appl Microbiol Biotechnol 2021; 105:2497-2511. [PMID: 33625547 DOI: 10.1007/s00253-021-11190-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 01/30/2021] [Accepted: 02/17/2021] [Indexed: 02/02/2023]
Abstract
Egicoccus halophilus EGI 80432T, a halotolerant bacterium isolated from a saline-alkaline soil, belongs to a member of the class Nitriliruptoria, which exhibits high adaptability to salt environments. At present, the detailed knowledge of the salinity adaptation strategies of Nitriliruptoria was limited except for one research by using comparative genomics analysis. Here, we investigated the salinity adaptation mechanism of E. halophilus EGI 80432T by comparative physiological and transcriptomic analyses. The results of physiological analyses showed that trehalose and glutamate were accumulated by salt stress and showed the maximum at moderate salinity condition. Furthermore, the contents of histidine, threonine, proline, and ectoine were increased with increasing salt concentration. We found that both 0% and 9% NaCl conditions resulted in increased expressions of genes involved in carbohydrate and energy metabolisms, but negatively affected the Na+ efflux, iron, and molybdate transport. Moreover, the high salt condition led to enhancement of transcription of genes required for the synthesis of compatible solutes, e.g., glutamate, histidine, threonine, proline, and ectoine, which agree with the results of physiological analyses. The above results revealed that E. halophilus EGI 80432T increased inorganic ions uptake and accumulated trehalose and glutamate in response to moderate salinity condition, while the salinity adaptation strategy was changed from a "salt-in-cytoplasm" strategy to a "compatible solute" strategy under high salinity condition. The findings in this study would promote further studies in salt tolerance molecular mechanism of Nitriliruptoria and provide a theoretical support for E. halophilus EGI 80432T's application in ecological restoration.Key Points• Salt stress affected gene expressions responsible for carbohydrate and energy metabolisms of E. halophilus EGI 8042T.• E. halophilus EGI 80432T significantly accumulated compatible solutes under salt stress.• E. halophilus EGI 80432T adopted a "compatible solute" strategy to withstand high salt stress.
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Affiliation(s)
- Dai-Di Chen
- Institute of Ecological Science, School of Life Science, South China Normal University, Guangzhou, 510631, People's Republic of China.,State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Bao-Zhu Fang
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China.,State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, People's Republic of China
| | - Ahmad Manzoor
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Yong-Hong Liu
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, People's Republic of China
| | - Li Li
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, People's Republic of China
| | - Osama Abdalla Abdelshafy Mohamad
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, People's Republic of China.,Department of Environmental Protection, Faculty of Environmental Agricultural Sciences, Arish University, Al-Arish, Egypt
| | - Wen-Sheng Shu
- Institute of Ecological Science, School of Life Science, South China Normal University, Guangzhou, 510631, People's Republic of China.
| | - Wen-Jun Li
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China. .,State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, People's Republic of China.
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152
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Fisher LA, Pontefract A, Som S, Carr CE, Klempay B, Schmidt B, Bowman J, Bartlett DH. Current state of athalassohaline deep‐sea hypersaline anoxic basin research—recommendations for future work and relevance to astrobiology. Environ Microbiol 2021; 23:3360-3369. [DOI: 10.1111/1462-2920.15414] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 01/26/2021] [Accepted: 01/27/2021] [Indexed: 01/06/2023]
Affiliation(s)
- Luke A. Fisher
- Marine Biology Research Division Scripps Institution of Oceanography, University of California San Diego La Jolla CA 92093‐0202 USA
| | | | - Sanjoy Som
- Blue Marble Space Institute of Science Seattle WA 98104 USA
| | - Christopher E. Carr
- Daniel Guggenheim School of Aerospace Engineering Georgia Institute of Technology Atlanta GA 30332 USA
- Earth and Atmospheric Sciences Georgia Institute of Technology Atlanta GA 30332 USA
| | - Benjamin Klempay
- Integrative Oceanography Division, Scripps Institution of Oceanography University of California San Diego La Jolla CA 92093‐0218 USA
| | - Britney Schmidt
- Earth and Atmospheric Sciences Georgia Institute of Technology Atlanta GA 30332 USA
| | - Jeff Bowman
- Integrative Oceanography Division, Scripps Institution of Oceanography University of California San Diego La Jolla CA 92093‐0218 USA
- Center for Microbiome Innovation University of California San Diego La Jolla CA 92093‐0218 USA
| | - Douglas H. Bartlett
- Marine Biology Research Division Scripps Institution of Oceanography, University of California San Diego La Jolla CA 92093‐0202 USA
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153
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The Survival of Haloferax mediterranei under Stressful Conditions. Microorganisms 2021; 9:microorganisms9020336. [PMID: 33567751 PMCID: PMC7915512 DOI: 10.3390/microorganisms9020336] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/21/2021] [Accepted: 02/03/2021] [Indexed: 11/28/2022] Open
Abstract
Haloarchaea can survive and thrive under exposure to a wide range of extreme environmental factors, which represents a potential interest to biotechnology. Growth responses to different stressful conditions were examined in the haloarchaeon Haloferax mediterranei R4. It has been demonstrated that this halophilic archaeon is able to grow between 10 and 32.5% (w/v) of sea water, at 32–52 °C, although it is expected to grow in temperatures lower than 32 °C, and between 5.75 and 8.75 of pH. Moreover, it can also grow under high metal concentrations (nickel, lithium, cobalt, arsenic), which are toxic to most living beings, making it a promising candidate for future biotechnological purposes and industrial applications. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) analysis quantified the intracellular ion concentrations of these four metals in Hfx. mediterranei, concluding that this haloarchaeon can accumulate Li+, Co2+, As5+, and Ni2+ within the cell. This paper is the first report on Hfx. mediterranei in which multiple stress conditions have been studied to explore the mechanism of stress resistance. It constitutes the most detailed study in Haloarchaea, and, as a consequence, new biotechnological and industrial applications have emerged.
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154
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Szymańska S, Sikora M, Hrynkiewicz K, Tyburski J, Tretyn A, Gołębiewski M. Choosing source of microorganisms and processing technology for next generation beet bioinoculant. Sci Rep 2021; 11:2829. [PMID: 33531601 PMCID: PMC7854725 DOI: 10.1038/s41598-021-82436-5] [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: 03/02/2020] [Accepted: 01/12/2021] [Indexed: 11/09/2022] Open
Abstract
The increase of human population and associated increasing demand for agricultural products lead to soil over-exploitation. Biofertilizers based on lyophilized plant material containing living plant growth-promoting microorganisms (PGPM) could be an alternative to conventional fertilizers that fits into sustainable agricultural technologies ideas. We aimed to: (1) assess the diversity of endophytic bacteria in sugar and sea beet roots and (2) determine the influence of osmoprotectants (trehalose and ectoine) addition during lyophilization on bacterial density, viability and salt tolerance. Microbiome diversity was assessed based on 16S rRNA amplicons sequencing, bacterial density and salt tolerance was evaluated in cultures, while bacterial viability was calculated by using fluorescence microscopy and flow cytometry. Here we show that plant genotype shapes its endophytic microbiome diversity and determines rhizosphere soil properties. Sea beet endophytic microbiome, consisting of genera characteristic for extreme environments, is more diverse and salt resistant than its crop relative. Supplementing osmoprotectants during root tissue lyophilization exerts a positive effect on bacterial community salt stress tolerance, viability and density. Trehalose improves the above-mentioned parameters more effectively than ectoine, moreover its use is economically advantageous, thus it may be used to formulate improved biofertilizers.
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Affiliation(s)
- Sonia Szymańska
- Department of Microbiology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University (NCU), Lwowska 1, 87-100, Toruń, Poland
| | - Marcin Sikora
- Center for Modern Interdisciplinary Technologies, Nicolaus Copernicus University (NCU), Toruń, Poland
| | - Katarzyna Hrynkiewicz
- Department of Microbiology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University (NCU), Lwowska 1, 87-100, Toruń, Poland.
| | - Jarosław Tyburski
- Center for Modern Interdisciplinary Technologies, Nicolaus Copernicus University (NCU), Toruń, Poland.,Chair of Plant Physiology and Biotechnology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University (NCU), Lwowska 1, 87-100, Toruń, Poland
| | - Andrzej Tretyn
- Center for Modern Interdisciplinary Technologies, Nicolaus Copernicus University (NCU), Toruń, Poland.,Chair of Plant Physiology and Biotechnology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University (NCU), Lwowska 1, 87-100, Toruń, Poland
| | - Marcin Gołębiewski
- Center for Modern Interdisciplinary Technologies, Nicolaus Copernicus University (NCU), Toruń, Poland. .,Chair of Plant Physiology and Biotechnology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University (NCU), Lwowska 1, 87-100, Toruń, Poland.
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155
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Gaonkar SK, Furtado IJ. Valorization of low-cost agro-wastes residues for the maximum production of protease and lipase haloextremozymes by Haloferax lucentensis GUBF-2 MG076078. Process Biochem 2021. [DOI: 10.1016/j.procbio.2020.10.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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156
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Gregory GJ, Boyd EF. Stressed out: Bacterial response to high salinity using compatible solute biosynthesis and uptake systems, lessons from Vibrionaceae. Comput Struct Biotechnol J 2021; 19:1014-1027. [PMID: 33613867 PMCID: PMC7876524 DOI: 10.1016/j.csbj.2021.01.030] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 01/18/2021] [Accepted: 01/20/2021] [Indexed: 12/19/2022] Open
Abstract
Bacteria have evolved mechanisms that allow them to adapt to changes in osmolarity and some species have adapted to live optimally in high salinity environments such as in the marine ecosystem. Most bacteria that live in high salinity do so by the biosynthesis and/or uptake of compatible solutes, small organic molecules that maintain the turgor pressure of the cell. Osmotic stress response mechanisms and their regulation among marine heterotrophic bacteria are poorly understood. In this review, we discuss what is known about compatible solute metabolism and transport and new insights gained from studying marine bacteria belonging to the family Vibrionaceae.
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Affiliation(s)
| | - E. Fidelma Boyd
- Corresponding author at: Department of Biological Sciences, 341 Wolf Hall, University of Delaware, Newark, DE 19716, United States.
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157
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Rai A, Smita N, Shabbir A, Jagadeeshwari U, Keertana T, Sasikala C, Ramana CV. Mesobacillus aurantius sp. nov., isolated from an orange-colored pond near a solar saltern. Arch Microbiol 2021; 203:1499-1507. [PMID: 33398397 DOI: 10.1007/s00203-020-02146-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 11/03/2020] [Accepted: 12/03/2020] [Indexed: 11/28/2022]
Abstract
An endospore producing, strict aerobic, Gram-stain-positive, orange-colored colony forming bacterium designated as strain JC1013T was isolated from an orange pond near a solar saltern of Tamil Nadu, India. Phylogenetic analysis of the 16S rRNA gene sequences indicated that strain was affiliated to the family Bacillaceae of the phylum Firmicutes. Strain showed highest 16S rRNA gene sequence identity of 98.7% with Mesobacillus selenatarsenatis SF-1 T and below 98.3% with other members of the genus Mesobacillus. Strain JC1013T produced carotenoid pigments and indole compounds. Major cellular fatty acids of strain JC1013T were iso-C15:0, anteiso-C15:0, C16:0 3-OH, iso-C17:0ω10c and summed feature 4 (iso-C17:1 I/ anteisoB). Polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, two unidentified aminolipids and four unidentified phospholipids. Strain JC1013T constituted m-diaminopimelic acid as diagnostic cell wall amino acids. MK-7 is the predominant menaquinone of strain JC1013T. The genome size of strain JC1013T was 4.6 Mbp and its G + C content was 42.7 mol%. For the affirmation of strain's taxonomic status, a detailed phylogenomic study was done. Based on the phylogenetic analyses, low ANI (84.6%), AAI (88.5%) values, in-silico DDH (< 29%) value, morphological, physiological and chemo-taxonomical characteristics, strain JC1013T was clearly distinguished from the nearest phylogenetic neighbor, Mesobacillus selenatarsenatis SF-1T to conclude that it is a new species of the genus Mesobacillus. We propose the name as Mesobacillus aurantius with type strain JC1013T (= NBRC 114146T = KACC 21451 T).
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Affiliation(s)
- Anusha Rai
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, P.O. Central University, Hyderabad, 500 046, India
| | - N Smita
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, P.O. Central University, Hyderabad, 500 046, India
| | - A Shabbir
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, P.O. Central University, Hyderabad, 500 046, India
| | - U Jagadeeshwari
- Bacterial Discovery Laboratory, Centre for Environment, Institute of Science and Technology, J. N. T. University H, Kukatpally, Hyderabad, 500 085, India
| | - T Keertana
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, P.O. Central University, Hyderabad, 500 046, India
| | - Ch Sasikala
- Bacterial Discovery Laboratory, Centre for Environment, Institute of Science and Technology, J. N. T. University H, Kukatpally, Hyderabad, 500 085, India.
| | - Ch V Ramana
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, P.O. Central University, Hyderabad, 500 046, India.
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158
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Halophilic Fungal Communities: Current Research and Future Challenges. Fungal Biol 2021. [DOI: 10.1007/978-3-030-60659-6_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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159
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Chen MY, Teng WK, Zhao L, Hu CX, Zhou YK, Han BP, Song LR, Shu WS. Comparative genomics reveals insights into cyanobacterial evolution and habitat adaptation. THE ISME JOURNAL 2021; 15:211-227. [PMID: 32943748 PMCID: PMC7852516 DOI: 10.1038/s41396-020-00775-z] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 08/31/2020] [Accepted: 09/04/2020] [Indexed: 02/07/2023]
Abstract
Cyanobacteria are photosynthetic prokaryotes that inhabit diverse aquatic and terrestrial environments. However, the evolutionary mechanisms involved in the cyanobacterial habitat adaptation remain poorly understood. Here, based on phylogenetic and comparative genomic analyses of 650 cyanobacterial genomes, we investigated the genetic basis of cyanobacterial habitat adaptation (marine, freshwater, and terrestrial). We show: (1) the expansion of gene families is a common strategy whereby terrestrial cyanobacteria cope with fluctuating environments, whereas the genomes of many marine strains have undergone contraction to adapt to nutrient-poor conditions. (2) Hundreds of genes are strongly associated with specific habitats. Genes that are differentially abundant in genomes of marine, freshwater, and terrestrial cyanobacteria were found to be involved in light sensing and absorption, chemotaxis, nutrient transporters, responses to osmotic stress, etc., indicating the importance of these genes in the survival and adaptation of organisms in specific habitats. (3) A substantial fraction of genes that facilitate the adaptation of Cyanobacteria to specific habitats are contributed by horizontal gene transfer, and such genetic exchanges are more frequent in terrestrial cyanobacteria. Collectively, our results further our understandings of the adaptations of Cyanobacteria to different environments, highlighting the importance of ecological constraints imposed by the environment in shaping the evolution of Cyanobacteria.
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Affiliation(s)
- Meng-Yun Chen
- School of Life Sciences, South China Normal University, Guangzhou, 510631, PR China
| | - Wen-Kai Teng
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, PR China
| | - Liang Zhao
- School of Life Sciences, South China Normal University, Guangzhou, 510631, PR China
| | - Chun-Xiang Hu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Science, 430072, Hubei, PR China
| | - Yang-Kai Zhou
- Shenzhen Key Laboratory of Marine Archaea Geo-Omics, Southern University of Science and Technology, Shenzhen, 518055, PR China
- Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, PR China
| | - Bo-Ping Han
- Department of Ecology and Institute of Hydrobiology, Jinan University, Guangzhou, 510632, PR China.
| | - Li-Rong Song
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Science, 430072, Hubei, PR China.
| | - Wen-Sheng Shu
- School of Life Sciences, South China Normal University, Guangzhou, 510631, PR China.
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160
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Yang J, Jiang H, Sun X, Huang J, Han M, Wang B. Distinct co-occurrence patterns of prokaryotic community between the waters and sediments in lakes with different salinity. FEMS Microbiol Ecol 2020; 97:5989694. [PMID: 33206972 DOI: 10.1093/femsec/fiaa234] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 11/16/2020] [Indexed: 11/13/2022] Open
Abstract
Temporal variations and co-occurrence patterns of the prokaryotic community in saline lakes remain elusive. In this study, we investigated the temporal variations of the prokaryotic community in six lakes with different salinity by using Illumina sequencing. The results showed that prokaryotic community compositions exhibited temporal variations in all studied lakes, which may be partially caused by temporal fluctuations of environmental variables (e.g. salinity, temperature, total nitrogen). Salinity fluctuations exhibited stronger influences on temporal variations of prokaryotic community composition in the lakes with low salinity than in those with high salinity. Stochastic factors (i.e. neutral processes) also contributed to temporal variations of prokaryotic community composition, and their contributions decreased with increasing salinity in the studied saline lakes. Network analysis showed that prokaryotic co-occurrence networks of the studied lakes exhibited non-random topology. Salinity affected the phylogenetic composition of nodes in the studied networks. The topological features (e.g. average connectivity and modularity) of the studied networks significantly differed between lake waters and sediments. Collectively, these results expand our knowledge of the mechanisms underlying prokaryotic community assembly and co-occurrence relationships in saline lakes with different salinity.
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Affiliation(s)
- Jian Yang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China
| | - Hongchen Jiang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China.,Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China
| | - Xiaoxi Sun
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China
| | - Jianrong Huang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China
| | - Mingxian Han
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China
| | - Beichen Wang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China
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161
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Kasirajan L, Maupin-Furlow JA. Halophilic archaea and their potential to generate renewable fuels and chemicals. Biotechnol Bioeng 2020; 118:1066-1090. [PMID: 33241850 DOI: 10.1002/bit.27639] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 10/27/2020] [Accepted: 11/17/2020] [Indexed: 12/16/2022]
Abstract
Lignocellulosic biofuels and chemicals have great potential to reduce our dependence on fossil fuels and mitigate air pollution by cutting down on greenhouse gas emissions. Chemical, thermal, and enzymatic processes are used to release the sugars from the lignocellulosic biomass for conversion to biofuels. These processes often operate at extreme pH conditions, high salt concentrations, and/or high temperature. These harsh treatments add to the cost of the biofuels, as most known biocatalysts do not operate under these conditions. To increase the economic feasibility of biofuel production, microorganisms that thrive in extreme conditions are considered as ideal resources to generate biofuels and value-added products. Halophilic archaea (haloarchaea) are isolated from hypersaline ecosystems with high salt concentrations approaching saturation (1.5-5 M salt concentration) including environments with extremes in pH and/or temperature. The unique traits of haloarchaea and their enzymes that enable them to sustain catalytic activity in these environments make them attractive resources for use in bioconversion processes that must occur across a wide range of industrial conditions. Biocatalysts (enzymes) derived from haloarchaea occupy a unique niche in organic solvent, salt-based, and detergent industries. This review focuses on the use of haloarchaea and their enzymes to develop and improve biofuel production. The review also highlights how haloarchaea produce value-added products, such as antibiotics, carotenoids, and bioplastic precursors, and can do so using feedstocks considered "too salty" for most microbial processes including wastes from the olive-mill, shell fish, and biodiesel industries.
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Affiliation(s)
- Lakshmi Kasirajan
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, USA.,Division of Crop Improvement, ICAR Sugarcane Breeding Institute, Coimbatore, India
| | - Julie A Maupin-Furlow
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, USA.,Genetics Institute, University of Florida, Gainesville, Florida, USA
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162
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Schwarz TS, Berkemer SJ, Bernhart SH, Weiß M, Ferreira-Cerca S, Stadler PF, Marchfelder A. Splicing Endonuclease Is an Important Player in rRNA and tRNA Maturation in Archaea. Front Microbiol 2020; 11:594838. [PMID: 33329479 PMCID: PMC7714728 DOI: 10.3389/fmicb.2020.594838] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 10/21/2020] [Indexed: 12/20/2022] Open
Abstract
In all three domains of life, tRNA genes contain introns that must be removed to yield functional tRNA. In archaea and eukarya, the first step of this process is catalyzed by a splicing endonuclease. The consensus structure recognized by the splicing endonuclease is a bulge-helix-bulge (BHB) motif which is also found in rRNA precursors. So far, a systematic analysis to identify all biological substrates of the splicing endonuclease has not been carried out. In this study, we employed CRISPRi to repress expression of the splicing endonuclease in the archaeon Haloferax volcanii to identify all substrates of this enzyme. Expression of the splicing endonuclease was reduced to 1% of its normal level, resulting in a significant extension of lag phase in H. volcanii growth. In the repression strain, 41 genes were down-regulated and 102 were up-regulated. As an additional approach in identifying new substrates of the splicing endonuclease, we isolated and sequenced circular RNAs, which identified excised introns removed from tRNA and rRNA precursors as well as from the 5' UTR of the gene HVO_1309. In vitro processing assays showed that the BHB sites in the 5' UTR of HVO_1309 and in a 16S rRNA-like precursor are processed by the recombinant splicing endonuclease. The splicing endonuclease is therefore an important player in RNA maturation in archaea.
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Affiliation(s)
| | - Sarah J Berkemer
- Bioinformatics, Department of Computer Science, Leipzig University, Leipzig, Germany.,Max Planck Institute for Mathematics in the Sciences, Leipzig, Germany.,Competence Center for Scalable Data Services and Solutions, Leipzig University, Leipzig, Germany
| | - Stephan H Bernhart
- Bioinformatics, Department of Computer Science, Leipzig University, Leipzig, Germany.,Interdisciplinary Center for Bioinformatics, Leipzig University, Leipzig, Germany
| | - Matthias Weiß
- Regensburg Center for Biochemistry, Biochemistry III - Institute of Biochemistry, Genetics and Microbiology, University of Regensburg, Regensburg, Germany
| | - Sébastien Ferreira-Cerca
- Regensburg Center for Biochemistry, Biochemistry III - Institute of Biochemistry, Genetics and Microbiology, University of Regensburg, Regensburg, Germany
| | - Peter F Stadler
- Bioinformatics, Department of Computer Science, Leipzig University, Leipzig, Germany.,Max Planck Institute for Mathematics in the Sciences, Leipzig, Germany.,Interdisciplinary Center for Bioinformatics, Leipzig University, Leipzig, Germany.,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany.,Research Center for Civilization Diseases, Leipzig University, Leipzig, Germany.,Facultad de Ciencias, Universidad Nacional de Colombia, Bogotá, Colombia.,Institute for Theoretical Chemistry, University of Vienna, Vienna, Austria.,Center for RNA in Technology and Health, University of Copenhagen, Frederiksberg, Denmark.,Santa Fe Institute, Santa Fe, NM, United States
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163
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Uritskiy G, Munn A, Dailey M, Gelsinger DR, Getsin S, Davila A, McCullough PR, Taylor J, DiRuggiero J. Environmental Factors Driving Spatial Heterogeneity in Desert Halophile Microbial Communities. Front Microbiol 2020; 11:578669. [PMID: 33193201 PMCID: PMC7606970 DOI: 10.3389/fmicb.2020.578669] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 09/24/2020] [Indexed: 12/22/2022] Open
Abstract
Spatial heterogeneity in microbial communities is observed in all natural ecosystems and can stem from both adaptations to local environmental conditions as well as stochastic processes. Extremophile microbial communities inhabiting evaporitic halite nodules (salt rocks) in the Atacama Desert, Chile, are a good model ecosystem for investigating factors leading to microbiome heterogeneity, due to their diverse taxonomic composition and the spatial segregation of individual nodules. We investigated the abiotic factors governing microbiome composition across different spatial scales, allowing for insight into the factors that govern halite colonization from regional desert-wide scales to micro-scales within individual nodules. We found that water availability and community drift account for microbiome assembly differently at different distance scales, with higher rates of cell dispersion at the smaller scales resulting in a more homogenous composition. This trend likely applies to other endoliths, and to non-desert communities, where dispersion between communities is limited. At the intra-nodule scales, a light availability gradient was most important in determining the distribution of microbial taxa despite intermixing by water displacement via capillary action.
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Affiliation(s)
- Gherman Uritskiy
- Department of Biology, Johns Hopkins University, Baltimore, MD, United States
| | - Adam Munn
- Department of Biology, Johns Hopkins University, Baltimore, MD, United States
| | - Micah Dailey
- Department of Biology, Johns Hopkins University, Baltimore, MD, United States
| | - Diego R. Gelsinger
- Department of Biology, Johns Hopkins University, Baltimore, MD, United States
| | - Samantha Getsin
- Department of Biology, Johns Hopkins University, Baltimore, MD, United States
| | - Alfonso Davila
- NASA Ames Research Center, Moffett Field, CA, United States
| | - P. R. McCullough
- Department of Physics and Astronomy, Johns Hopkins University, and Space Telescope Science Institute, Baltimore, MD, United States
| | - James Taylor
- Department of Biology, Johns Hopkins University, Baltimore, MD, United States
- Department of Computer Science, Johns Hopkins University, Baltimore, MD, United States
| | - Jocelyne DiRuggiero
- Department of Biology, Johns Hopkins University, Baltimore, MD, United States
- Department of Earth & Planetary Sciences, Johns Hopkins University, Baltimore, MD, United States
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Fongaro G, Maia GA, Rogovski P, Cadamuro RD, Lopes JC, Moreira RS, Camargo AF, Scapini T, Stefanski FS, Bonatto C, Marques Souza DS, Stoco PH, Duarte RTD, Cabral da Cruz AC, Wagner G, Treichel H. Extremophile Microbial Communities and Enzymes for Bioenergetic Application Based on Multi-Omics Tools. Curr Genomics 2020; 21:240-252. [PMID: 33071618 PMCID: PMC7521039 DOI: 10.2174/1389202921999200601144137] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 02/02/2020] [Accepted: 04/20/2020] [Indexed: 12/03/2022] Open
Abstract
Abstract: Genomic and proteomic advances in extremophile microorganism studies are increasingly demonstrating their ability to produce a variety of enzymes capable of converting biomass into bioenergy. Such microorganisms are found in environments with nutritional restrictions, anaerobic environments, high salinity, varying pH conditions and extreme natural environments such as hydrothermal vents, soda lakes, and Antarctic sediments. As extremophile microorganisms and their enzymes are found in widely disparate locations, they generate new possibilities and opportunities to explore biotechnological prospecting, including biofuels (biogas, hydrogen and ethanol) with an aim toward using multi-omics tools that shed light on biotechnological breakthroughs.
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Affiliation(s)
- Gislaine Fongaro
- 1Department of Microbiology, Immunology, and Parasitology, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 2Laboratory of Microbiology and Bioprocess, Federal University of Fronteira Sul, Erechim, RS, Brazil; 3Department of Chemical and Food Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 4Department of Dentistry, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Guilherme Augusto Maia
- 1Department of Microbiology, Immunology, and Parasitology, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 2Laboratory of Microbiology and Bioprocess, Federal University of Fronteira Sul, Erechim, RS, Brazil; 3Department of Chemical and Food Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 4Department of Dentistry, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Paula Rogovski
- 1Department of Microbiology, Immunology, and Parasitology, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 2Laboratory of Microbiology and Bioprocess, Federal University of Fronteira Sul, Erechim, RS, Brazil; 3Department of Chemical and Food Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 4Department of Dentistry, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Rafael Dorighello Cadamuro
- 1Department of Microbiology, Immunology, and Parasitology, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 2Laboratory of Microbiology and Bioprocess, Federal University of Fronteira Sul, Erechim, RS, Brazil; 3Department of Chemical and Food Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 4Department of Dentistry, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Joana Camila Lopes
- 1Department of Microbiology, Immunology, and Parasitology, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 2Laboratory of Microbiology and Bioprocess, Federal University of Fronteira Sul, Erechim, RS, Brazil; 3Department of Chemical and Food Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 4Department of Dentistry, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Renato Simões Moreira
- 1Department of Microbiology, Immunology, and Parasitology, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 2Laboratory of Microbiology and Bioprocess, Federal University of Fronteira Sul, Erechim, RS, Brazil; 3Department of Chemical and Food Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 4Department of Dentistry, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Aline Frumi Camargo
- 1Department of Microbiology, Immunology, and Parasitology, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 2Laboratory of Microbiology and Bioprocess, Federal University of Fronteira Sul, Erechim, RS, Brazil; 3Department of Chemical and Food Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 4Department of Dentistry, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Thamarys Scapini
- 1Department of Microbiology, Immunology, and Parasitology, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 2Laboratory of Microbiology and Bioprocess, Federal University of Fronteira Sul, Erechim, RS, Brazil; 3Department of Chemical and Food Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 4Department of Dentistry, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Fábio Spitza Stefanski
- 1Department of Microbiology, Immunology, and Parasitology, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 2Laboratory of Microbiology and Bioprocess, Federal University of Fronteira Sul, Erechim, RS, Brazil; 3Department of Chemical and Food Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 4Department of Dentistry, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Charline Bonatto
- 1Department of Microbiology, Immunology, and Parasitology, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 2Laboratory of Microbiology and Bioprocess, Federal University of Fronteira Sul, Erechim, RS, Brazil; 3Department of Chemical and Food Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 4Department of Dentistry, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Doris Sobral Marques Souza
- 1Department of Microbiology, Immunology, and Parasitology, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 2Laboratory of Microbiology and Bioprocess, Federal University of Fronteira Sul, Erechim, RS, Brazil; 3Department of Chemical and Food Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 4Department of Dentistry, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Patrícia Hermes Stoco
- 1Department of Microbiology, Immunology, and Parasitology, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 2Laboratory of Microbiology and Bioprocess, Federal University of Fronteira Sul, Erechim, RS, Brazil; 3Department of Chemical and Food Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 4Department of Dentistry, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Rubens Tadeu Delgado Duarte
- 1Department of Microbiology, Immunology, and Parasitology, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 2Laboratory of Microbiology and Bioprocess, Federal University of Fronteira Sul, Erechim, RS, Brazil; 3Department of Chemical and Food Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 4Department of Dentistry, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Ariadne Cristiane Cabral da Cruz
- 1Department of Microbiology, Immunology, and Parasitology, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 2Laboratory of Microbiology and Bioprocess, Federal University of Fronteira Sul, Erechim, RS, Brazil; 3Department of Chemical and Food Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 4Department of Dentistry, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Glauber Wagner
- 1Department of Microbiology, Immunology, and Parasitology, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 2Laboratory of Microbiology and Bioprocess, Federal University of Fronteira Sul, Erechim, RS, Brazil; 3Department of Chemical and Food Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 4Department of Dentistry, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Helen Treichel
- 1Department of Microbiology, Immunology, and Parasitology, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 2Laboratory of Microbiology and Bioprocess, Federal University of Fronteira Sul, Erechim, RS, Brazil; 3Department of Chemical and Food Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil; 4Department of Dentistry, Federal University of Santa Catarina, Florianópolis, SC, Brazil
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Van Thuoc D, Loan TT, Trung TA, Van Quyen N, Tung QN, Tien PQ, Sudesh K. Genome Mining Reveals the Biosynthetic Pathways of Polyhydroxyalkanoate and Ectoines of the Halophilic Strain Salinivibrio proteolyticus M318 Isolated from Fermented Shrimp Paste. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2020; 22:651-660. [PMID: 32827070 DOI: 10.1007/s10126-020-09986-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 08/03/2020] [Indexed: 06/11/2023]
Abstract
Salinivibrio proteolyticus M318, a halophilic bacterium isolated from fermented shrimp paste, is able to produce polyhydroxyalkanoate (PHA) from different carbon sources. In this study, we report the whole-genome sequence of strain M138, which comprises 2 separated chromosomes and 2 plasmids, and the complete genome contains 3,605,935 bp with an average GC content of 49.9%. The genome of strain M318 contains 3341 genes, 98 tRNA genes, and 28 rRNA genes. The 16S rRNA gene sequence and average nucleotide identity analysis associated with morphological and biochemical tests showed that this strain has high homology to the reference strain Salinivibrio proteolyticus DSM 8285. The genes encoding key enzymes for PHA and ectoine synthesis were identified from the bacterial genome. In addition, the TeaABC transporter responsible for ectoine uptake from the environment and the operon doeABXCD responsible for the degradation of ectoine were also detected. Strain M318 was able to produce poly(3-hydroxybutyrate) [P(3HB)] from different carbon sources such as glycerol, maltose, glucose, fructose, and starch. The ability to produce ectoines at different NaCl concentrations was investigated. High ectoine content of 26.2% of cell dry weight was obtained by this strain at 18% NaCl. This report provides genetic information regarding adaptive mechanisms of strain M318 to stress conditions, as well as new knowledge to facilitate the application of this strain as a bacterial cell factory for the production of PHA and ectoine.
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Affiliation(s)
- Doan Van Thuoc
- Faculty of Biology, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi, Vietnam.
| | - Tran Thi Loan
- Faculty of Biology, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi, Vietnam
| | - Trieu Anh Trung
- Faculty of Biology, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi, Vietnam
| | - Nguyen Van Quyen
- Faculty of Biology, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi, Vietnam
| | - Quach Ngoc Tung
- Institute of Biotechnology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Caugiay, Hanoi, Vietnam
| | - Phi Quyet Tien
- Institute of Biotechnology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Caugiay, Hanoi, Vietnam
| | - Kumar Sudesh
- School of Biological Sciences, Universiti Sains Malaysia, 11800, Penang, Malaysia
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166
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Matarredona L, Camacho M, Zafrilla B, Bonete MJ, Esclapez J. The Role of Stress Proteins in Haloarchaea and Their Adaptive Response to Environmental Shifts. Biomolecules 2020; 10:biom10101390. [PMID: 33003558 PMCID: PMC7601130 DOI: 10.3390/biom10101390] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/18/2020] [Accepted: 09/24/2020] [Indexed: 12/26/2022] Open
Abstract
Over the years, in order to survive in their natural environment, microbial communities have acquired adaptations to nonoptimal growth conditions. These shifts are usually related to stress conditions such as low/high solar radiation, extreme temperatures, oxidative stress, pH variations, changes in salinity, or a high concentration of heavy metals. In addition, climate change is resulting in these stress conditions becoming more significant due to the frequency and intensity of extreme weather events. The most relevant damaging effect of these stressors is protein denaturation. To cope with this effect, organisms have developed different mechanisms, wherein the stress genes play an important role in deciding which of them survive. Each organism has different responses that involve the activation of many genes and molecules as well as downregulation of other genes and pathways. Focused on salinity stress, the archaeal domain encompasses the most significant extremophiles living in high-salinity environments. To have the capacity to withstand this high salinity without losing protein structure and function, the microorganisms have distinct adaptations. The haloarchaeal stress response protects cells against abiotic stressors through the synthesis of stress proteins. This includes other heat shock stress proteins (Hsp), thermoprotectants, survival proteins, universal stress proteins, and multicellular structures. Gene and family stress proteins are highly conserved among members of the halophilic archaea and their study should continue in order to develop means to improve for biotechnological purposes. In this review, all the mechanisms to cope with stress response by haloarchaea are discussed from a global perspective, specifically focusing on the role played by universal stress proteins.
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167
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Pal S, Biswas R, Misra A, Sar A, Banerjee S, Mukherjee P, Dam B. Poorly known microbial taxa dominate the microbiome of hypersaline Sambhar Lake salterns in India. Extremophiles 2020; 24:875-885. [PMID: 32955600 DOI: 10.1007/s00792-020-01201-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 09/07/2020] [Indexed: 01/21/2023]
Abstract
Inland athalassohaline solar salterns provide unique opportunity to study microbial successions along salinity gradients that resemble transition in natural hypersaline lakes. We analyzed for the first time 16S rRNA gene amplicon sequences of bacteria (V1-V2) and archaea (V4-V5) in saltern brines of India's largest inland hypersaline Sambhar Lake. Brines of the salterns (S1-S4) are alkaline (pH 9.5-10.5) with salinities of 130, 170, 280 and 350 gL-1 respectively. 16S rRNA gene copy-number of archaea outnumbered that of bacteria in all salterns. Their diversity also increased along S1 through S4, while that of bacteria decreased. Brines of S3 and S4 were dominated by specialized extreme halophilic bacterial (Halanaerobiales, Rhodothermaceae) and archaeal (Halobacteriales, Haloferacales) members with recognized salt-in strategy for osmoadaptation. Microbial assemblages positively correlated to saltern pH, total salinity, and ionic composition. Archaea in S1 and S2 were unprecedentedly represented by poorly known as-yet uncultivated groups, Woesearchaeota (90.35-93.51%) and Nanohaloarchaeota that belong to the newly proposed nano-sized superphylum DPANN. In fact, these taxa were identified in archaeal datasets of other athalassohaline salterns after re-analysis using latest RDP database. Thus, microbial compositions in hypersaline lakes are complex and need revisit particularly for their archaeal diversity to understand their hitherto unknown ecological function in extreme environments.
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Affiliation(s)
- Srikanta Pal
- Microbiology Laboratory, Department of Botany (DST-FIST and UGC-DRS Funded), Institute of Science, Visva-Bharati (A Central University), Santiniketan, West Bengal, 731235, India
| | - Raju Biswas
- Microbiology Laboratory, Department of Botany (DST-FIST and UGC-DRS Funded), Institute of Science, Visva-Bharati (A Central University), Santiniketan, West Bengal, 731235, India
| | - Arijit Misra
- Microbiology Laboratory, Department of Botany (DST-FIST and UGC-DRS Funded), Institute of Science, Visva-Bharati (A Central University), Santiniketan, West Bengal, 731235, India
| | - Abhijit Sar
- Microbiology Laboratory, Department of Botany (DST-FIST and UGC-DRS Funded), Institute of Science, Visva-Bharati (A Central University), Santiniketan, West Bengal, 731235, India
| | - Sohini Banerjee
- Microbiology Laboratory, Department of Botany (DST-FIST and UGC-DRS Funded), Institute of Science, Visva-Bharati (A Central University), Santiniketan, West Bengal, 731235, India.,Present address: Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Puja Mukherjee
- Microbiology Laboratory, Department of Botany (DST-FIST and UGC-DRS Funded), Institute of Science, Visva-Bharati (A Central University), Santiniketan, West Bengal, 731235, India
| | - Bomba Dam
- Microbiology Laboratory, Department of Botany (DST-FIST and UGC-DRS Funded), Institute of Science, Visva-Bharati (A Central University), Santiniketan, West Bengal, 731235, India.
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Sagar A, Sayyed RZ, Ramteke PW, Sharma S, Marraiki N, Elgorban AM, Syed A. ACC deaminase and antioxidant enzymes producing halophilic Enterobacter sp. PR14 promotes the growth of rice and millets under salinity stress. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2020; 26:1847-1854. [PMID: 32943820 PMCID: PMC7468042 DOI: 10.1007/s12298-020-00852-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 07/06/2020] [Accepted: 07/14/2020] [Indexed: 05/18/2023]
Abstract
Rhizobacteria are known to ameliorate salinity stress through a wide variety of mechanisms including the production of aminocyclopropane-1-carboxylate deaminase (ACCD). Application of ACCD positive halophilic rhizobacteria ameliorate soil salinity along with its plant growth promotion activity. An effect of the inoculation of ACCD and antioxidant positive and halophilic Enterobacter sp. PR14 was reported on the seed germination and growth of rice and millet seedlings grown in saline and alkaline soil was evaluated. The rhizobacterial strain grew well over a high level of NaCl (15-90 M); at a wide range of pH (5-9); and produced a wide variety of plant growth-promoting (PGP) traits viz. indole-acetic acid (13 µg mL-1), ACCD (5.20 M mg-1 h-1), phosphate solubilization (0.99 g mL-1) and antioxidant enzymes such as superoxide dismutase (5.143 IU mg-1 protein), catalase (0.43 IU mg-1 protein) and glutathione (19.077 µg mg-1 protein) during log phase (30 h) of its growth. The stress with alkaline pH (9) and high salinity (90 M) caused a further increase in the synthesis of PGP traits, ACCD, and antioxidant enzymes. The combined application of Enterobacter sp. PR14, ammonium sulfate (as a substitute of ACC), and NaCl (30 M) resulted in a further increase in the seed germination and vigor in rice and millets vis-à-vis control and other treatments. After 15 days of growth, 61.72% more seed germination in rice and millet and 63.15% increase in sorghum was recorded over the control, and after 30 days of growth, 99.67%, 30%, and 54%, root length 50%, 30% and 54% shoot length in rice, sorghum and millet were observed respectively. A significant increase of 38.13%, 30.75%, and 16.36% in dry weight of rice, sorghum, and millet shoots was recorded respectively. Enterobacter sp PR 14, showing multiple plant growth-promoting traits has a great potential to be used as an efficient bioinoculant for growth promotion of rice and millets under alkaline and saline conditions.
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Affiliation(s)
- A. Sagar
- Department of Microbiology and Biotechnology, Meerut Institute of Engineering and Technology, Meerut, Uttar Pradesh India
- Department of Industrial Microbiology, Sam Higginbottom University of Agriculture, Technology and Sciences, Allahabad, UP 211007 India
| | - R. Z. Sayyed
- Department of Microbiology, PSGVP Mandal’s, Arts, Science and Commerce College, Shahada, Maharashtra 425 409 India
| | - P. W. Ramteke
- Department of Biological Sciences, Sam Higginbottom University of Agriculture, Technology and Sciences, Allahabad, UP 211007 India
| | - S. Sharma
- Department of Microbiology and Biotechnology, Meerut Institute of Engineering and Technology, Meerut, Uttar Pradesh India
| | - Najat Marraiki
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, 11451 Saudi Arabia
| | - Abdallah M. Elgorban
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, 11451 Saudi Arabia
- Center of Excellence in Biotechnology Research, King Saud University, P.O Box 2455, Riyadh, Saudi Arabia
| | - Asad Syed
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, 11451 Saudi Arabia
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169
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Abstract
The brines of natural salt lakes with total salt concentrations exceeding 30% are often colored red by dense communities of halophilic microorganisms. Such red brines are found in the north arm of Great Salt Lake, Utah, in the alkaline hypersaline lakes of the African Rift Valley, and in the crystallizer ponds of coastal and inland salterns where salt is produced by evaporation of seawater or some other source of saline water. Red blooms were also reported in the Dead Sea in the past. Different types of pigmented microorganisms may contribute to the coloration of the brines. The most important are the halophilic archaea of the class Halobacteria that contain bacterioruberin carotenoids as well as bacteriorhodopsin and other retinal pigments, β-carotene-rich species of the unicellular green algal genus Dunaliella and bacteria of the genus Salinibacter (class Rhodothermia) that contain the carotenoid salinixanthin and the retinal protein xanthorhodopsin. Densities of prokaryotes in red brines often exceed 2-3×107 cells/mL. I here review the information on the biota of the red brines, the interactions between the organisms present, as well as the possible roles of the red halophilic microorganisms in the salt production process and some applied aspects of carotenoids and retinal proteins produced by the different types of halophiles inhabiting the red brines.
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Affiliation(s)
- Aharon Oren
- The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.
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170
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Plant-archaea relationships: a potential means to improve crop production in arid and semi-arid regions. World J Microbiol Biotechnol 2020; 36:133. [PMID: 32772189 DOI: 10.1007/s11274-020-02910-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 08/04/2020] [Indexed: 12/14/2022]
Abstract
Crop production in arid and semi-arid regions of the world is limited by several abiotic factors, including water stress, temperature extremes, low soil fertility, high soil pH, low soil water-holding capacity, and low soil organic matter. Moreover, arid and semi-arid areas experience low levels of rainfall with high spatial and temporal variability. Also, the indiscriminate use of chemicals, a practice that characterizes current agricultural practice, promotes crop and soil pollution potentially resulting in serious human health and environmental hazards. A reliable and sustainable alternative to current farming practice is, therefore, a necessity. One such option includes the use of plant growth-promoting microbes that can help to ameliorate some of the adverse effects of these multiple stresses. In this regard, archaea, functional components of the plant microbiome that are found both in the rhizosphere and the endosphere may contribute to the promotion of plant growth. Archaea can survive in extreme habitats such as areas with high temperatures and hypersaline water. No cases of archaea pathogenicity towards plants have been reported. Archaea appear to have the potential to promote plant growth, improve nutrient supply and protect plants against various abiotic stresses. A better understanding of recent developments in archaea functional diversity, plant colonizing ability, and modes of action could facilitate their eventual usage as reliable components of sustainable agricultural systems. The research discussed herein, therefore, addresses the potential role of archaea to improve sustainable crop production in arid and semi-arid areas.
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171
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Huang J, Yang J, Jiang H, Wu G, Liu W, Wang B, Xiao H, Han J. Microbial Responses to Simulated Salinization and Desalinization in the Sediments of the Qinghai-Tibetan Lakes. Front Microbiol 2020; 11:1772. [PMID: 32849396 PMCID: PMC7426462 DOI: 10.3389/fmicb.2020.01772] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 07/06/2020] [Indexed: 12/21/2022] Open
Abstract
Uncovering microbial response to salinization or desalinization is of great importance to understanding of the influence of global climate change on lacustrine microbial ecology. In this study, to simulate salinization and desalinization, sediments from Erhai Lake (salinity 0.3-0.8 g/L) and Chaka Lake (salinity 299.3-350.7 g/L) on the Qinghai-Tibetan Plateau were transplanted into different lakes with a range of salinity of 0.3-299.3 g/L, followed by in situ incubation for 50 days and subsequent geochemical and microbial analyses. Desalinization was faster than salinization in the transplanted sediments. The salinity of the transplanted sediment increased and decreased in the salinization and desalinization simulation experiments, respectively. The TOC contents of the transplanted sediments were lower than that of their undisturbed counterparts in the salinization experiments, whereas they had a strong negative linear relationship with salinity in the desalinization experiments. Microbial diversity decreased in response to salinization and desalinization, and microbial community dissimilarity significantly (P < 0.01) increased with salinity differences between the transplanted sediments and their undisturbed counterparts. Microbial groups belonging to Gammaproteobacteria and Actinobacteria became abundant in salinization whereas Bacteroidetes and Chloroflexi became dominant in desalinization. Among the predicted microbial functions, hydrogenotrophic methanogenesis, methanogenesis through CO2 reduction with H2, nitrate/nitrogen respiration, and nitrification increased in salinization; in desalinization, enhancement was observed for respiration of sulfur compounds, sulfate respiration, sulfur respiration, thiosulfate respiration, hydrocarbon degradation, chemoheterotrophy, and fermentation, whereas depressing was found for aerobic ammonia oxidation, nitrate/nitrogen respiration, nitrification, nitrite respiration, manganese oxidation, aerobic chemoheterotrophy, and phototrophy. Such microbial variations could be explained by changes of transplantation, salinity, and covarying variables. In summary, salinization and desalinization had profound influence on the geochemistry, microbial community, and function in lakes.
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Affiliation(s)
- Jianrong Huang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Jian Yang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Hongchen Jiang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China.,State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Urumqi, China
| | - Geng Wu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Wen Liu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Beichen Wang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Haiyi Xiao
- Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan, China
| | - Jibin Han
- Key Laboratory of Salt Lake Geology and Environment of Qinghai Province, Qinghai Institute of Salt Lakes, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Xining, China
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172
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Myers MR, King G. Halobacterium bonnevillei sp. nov., Halobaculum saliterrae sp. nov. and Halovenus carboxidivorans sp. nov., three novel carbon monoxide-oxidizing Halobacteria from saline crusts and soils. Int J Syst Evol Microbiol 2020; 70:4261-4268. [DOI: 10.1099/ijsem.0.004282] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Three novel carbon monoxide-oxidizing Halobacteria were isolated from Bonneville Salt Flats (Utah, USA) salt crusts and nearby saline soils. Phylogenetic analysis of 16S rRNA gene sequences revealed that strains PCN9T, WSA2T and WSH3T belong to the genera
Halobacterium
,
Halobaculum
and
Halovenus
, respectively. Strains PCN9T, WSA2T and WSH3T grew optimally at 40 °C (PCN9T) or 50 °C (WSA2T, WSH3T). NaCl optima were 3 M (PCN9T, WSA2T) or 4 M NaCl (WSH3T). Carbon monoxide was oxidized by all isolates, each of which contained a molybdenum-dependent CO dehydrogenase. G+C contents for the three respective isolates were 66.75, 67.62, and 63.97 mol% as derived from genome analyses. The closest phylogenetic relatives for PCN9T, WSA2T and WSH3T were
Halobacterium noricense
A1T,
Halobaculum roseum
D90T and
Halovenus aranensis
EB27T with 98.71, 98.19 and 95.95 % 16S rRNA gene sequence similarities, respectively. Genome comparisons of PCN9T with
Halobacterium noricense
A1T yielded an average nucleotide identity (ANI) of 82.0% and a digital DNA–DNA hybridization (dDDH) value of 25.7 %; comparisons of WSA2T with
Halobaculum roseum
D90T yielded ANI and dDDH values of 86.34 and 31.1 %, respectively. The ANI value for a comparison of WSH3T with
Halovenus aranensis
EB27T was 75.2 %. Physiological, biochemical, genetic and genomic characteristics of PCN9T, WSA2T and WSH3T differentiated them from their closest phylogenetic neighbours and indicated that they represent novel species for which the names Halobaculum bonnevillei, Halobaculum saliterrae and Halovenus carboxidivorans are proposed, respectively. The type strains are PCN9T (=JCM 32472=LMG 31022=ATCC TSD-126), WSA2T (=JCM 32473=ATCC TSD-127) and WSH3T (=JCM 32474=ATCC TSD-128).
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Affiliation(s)
- Marisa R. Myers
- Louisiana State University, Department of Biology Sciences, Baton Rouge, LA 70803, USA
| | - G.M. King
- Louisiana State University, Department of Biology Sciences, Baton Rouge, LA 70803, USA
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173
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Culturable microbial diversity in the rhizosphere of different biotypes under variable salinity. Trop Ecol 2020. [DOI: 10.1007/s42965-020-00089-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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174
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Alternative Bioremediation Agents against Haloacids, Haloacetates and Chlorpyrifos Using Novel Halogen-Degrading Bacterial Isolates from the Hypersaline Lake Tuz. Catalysts 2020. [DOI: 10.3390/catal10060651] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The indiscriminate use of chemical pesticides alongside the expansion of large-scale industries globally can critically jeopardize marine ecology and the well-being of mankind. This is because the agricultural runoffs and industrial effluents eventually enter waterways before flowing into highly saline environments i.e., oceans. Herein, the study assessed two novel bacterial isolates, Bacillus subtilis strain H1 and Bacillus thuringiensis strain H2 from the hypersaline Lake Tuz in Turkey to degrade recalcitrant haloalkanoic acids, haloacetates and chlorpyrifos, and consequently, identify their optimal pollutant concentrations, pH and temperature alongside salt-tolerance thresholds. Bacillus strains H1 and H2 optimally degraded 2,2-dichloropropionic acid (2,2-DCP) under similar incubation conditions (pH 8.0, 30 °C), except the latter preferred a higher concentration of pollutants as well as salinity at 30 mM and 35%, respectively, while strain H1 grew well on 20 mM at <30%. While both isolates could degrade all substrates used, the dehalogenase gene from strain H1 could not be amplified. Capacity of the H2 bacterial isolate to degrade 2,2-DCP was affirmed by the detection of the 795 bp putative halotolerant dehalogenase gene after a successful polymerase chain reaction (PCR) amplification. Hence, the findings envisage the potential of both isolates as bio-degraders of recalcitrant halogenated compounds and those of the same chemical family as chlorpyrifos, in saline environments.
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175
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Isobe K, Bouskill NJ, Brodie EL, Sudderth EA, Martiny JBH. Phylogenetic conservation of soil bacterial responses to simulated global changes. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190242. [PMID: 32200749 PMCID: PMC7133522 DOI: 10.1098/rstb.2019.0242] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/22/2020] [Indexed: 01/03/2023] Open
Abstract
Soil bacterial communities are altered by anthropogenic drivers such as climate change-related warming and fertilization. However, we lack a predictive understanding of how bacterial communities respond to such global changes. Here, we tested whether phylogenetic information might be more predictive of the response of bacterial taxa to some forms of global change than others. We analysed the composition of soil bacterial communities from perturbation experiments that simulated warming, drought, elevated CO2 concentration and phosphorus (P) addition. Bacterial responses were phylogenetically conserved to all perturbations. The phylogenetic depth of these responses varied minimally among the types of perturbations and was similar when merging data across locations, implying that the context of particular locations did not affect the phylogenetic pattern of response. We further identified taxonomic groups that responded consistently to each type of perturbation. These patterns revealed that, at the level of family and above, most groups responded consistently to only one or two types of perturbations, suggesting that traits with different patterns of phylogenetic conservation underlie the responses to different perturbations. We conclude that a phylogenetic approach may be useful in predicting how soil bacterial communities respond to a variety of global changes. This article is part of the theme issue 'Conceptual challenges in microbial community ecology'.
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Affiliation(s)
- Kazuo Isobe
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Nicholas J. Bouskill
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Eoin L. Brodie
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA, USA
| | - Erika A. Sudderth
- Center for Environmental Studies, Brown University, Providence, RI, USA
| | - Jennifer B. H. Martiny
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, USA
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176
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Uritskiy G, Tisza MJ, Gelsinger DR, Munn A, Taylor J, DiRuggiero J. Cellular life from the three domains and viruses are transcriptionally active in a hypersaline desert community. Environ Microbiol 2020; 23:3401-3417. [DOI: 10.1111/1462-2920.15023] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 04/12/2020] [Indexed: 02/03/2023]
Affiliation(s)
- Gherman Uritskiy
- Department of Biology Johns Hopkins University Baltimore MD 21218 USA
| | - Michael J. Tisza
- Department of Biology Johns Hopkins University Baltimore MD 21218 USA
- Laboratory of Cellular Oncology NCI, NIH Bethesda MD 20892‐4263 USA
| | | | - Adam Munn
- Department of Biology Johns Hopkins University Baltimore MD 21218 USA
| | - James Taylor
- Department of Biology Johns Hopkins University Baltimore MD 21218 USA
- Department of Computer Science Johns Hopkins University Baltimore MD 21218 USA
| | - Jocelyne DiRuggiero
- Department of Biology Johns Hopkins University Baltimore MD 21218 USA
- Department of Earth and Planetary Sciences Johns Hopkins University Baltimore MD 21218 USA
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177
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Nature and bioprospecting of haloalkaliphilics: a review. World J Microbiol Biotechnol 2020; 36:66. [DOI: 10.1007/s11274-020-02841-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 04/14/2020] [Indexed: 01/07/2023]
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178
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Breisch J, Averhoff B. Identification of osmo-dependent and osmo-independent betaine-choline-carnitine transporters in Acinetobacter baumannii: role in osmostress protection and metabolic adaptation. Environ Microbiol 2020; 22:2724-2735. [PMID: 32219961 DOI: 10.1111/1462-2920.14998] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 03/22/2020] [Indexed: 12/28/2022]
Abstract
Acinetobacter baumannii is outstanding for its ability to cope with low water activities and therefore its adaptation mechanism to osmotic stress. Here we report on the identification and characterization of five different secondary active compatible solute transporters, belonging to the betaine-choline-carnitine transporter (BCCT) family. Our studies revealed two choline-specific and three glycine betaine-specific BCCTs. Activity of the BCCTs was differentially dependent to the osmolality: one choline and one betaine transporter were osmostress-independent. Addition of choline to resting cells of Acinetobacter grown in the presence of the co-substrate choline or with phosphatidylcholine as sole carbon source led to ATP synthesis in the wild type but not in the BCCT quadruple mutant. This indicates that the BCCTs are essential to transport the energy substrate choline. The role of the different BCCTs in osmostress resistance and in metabolic adaptation of A. baumannii to the human host is discussed.
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Affiliation(s)
- Jennifer Breisch
- Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe-University Frankfurt am Main, Germany
| | - Beate Averhoff
- Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe-University Frankfurt am Main, Germany
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179
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Han D, Cui HL. Salinibaculum litoreum gen. nov., sp. nov., isolated from salted brown alga Laminaria. Int J Syst Evol Microbiol 2020; 70:2879-2887. [PMID: 32213254 DOI: 10.1099/ijsem.0.004114] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024] Open
Abstract
A novel Gram-stain-negative, aerobic and rod-shaped halophilic archaeon, designated HD8-45T, was isolated from the red brine of salted brown alga Laminaria produced at Dalian, PR China. According to the results of 16S rRNA gene and rpoB' gene sequence comparisons, strain HD8-45T showed the highest sequence similarity to the corresponding genes of Salinirussus salinus YGH44T (95.1 and 85.2 % similarities, respectively), Halovenus aranensis EB27T (91.2 and 86.0 % similarities, respectively). The low sequence similarity and the phylogeny implied the novel generic status of strain HD8-45T. Genomic relatedness analyses showed that strain HD8-45T were clearly distinguished from other species in the order Halobacteriales, with average nucleotide identity, amino acid identity and in silico DNA-DNA hybridization values not more than 75.1, 65.6 and 21.5 %. The polar lipid pattern contained phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, two major glycolipids and two minor glycolipids. The two major glycolipids and a minor glycolipid were chromatographically identical to disulfated mannosyl glucosyl diether, sulfated mannosyl glucosyl diether and mannosyl glucosyl diether, respectively. The major respiratory quinones were menaquinone MK-8 and MK-8(H2). The DNA G+C content was 62.0 mol% (Tm) and 61.9 mol% (genome). All these results showed that strain HD8-45T represents a novel species of a new genus in the order Halobacteriales, for which the name Salinibaculum litoreum gen. nov., sp. nov. is proposed. The type strain of Salinibaculum litoreum is HD8-45T (=CGMCC 1.15328T=JCM 31107T).
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Affiliation(s)
- Dong Han
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, PR China
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180
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Feeding Formula Eliminates the Necessity of Bacterial Dysbiosis and Induces Inflammation and Injury in the Paneth Cell Disruption Murine NEC Model in an Osmolality-Dependent Manner. Nutrients 2020; 12:nu12040900. [PMID: 32224880 PMCID: PMC7230818 DOI: 10.3390/nu12040900] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 03/19/2020] [Accepted: 03/24/2020] [Indexed: 01/08/2023] Open
Abstract
Necrotizing enterocolitis (NEC) remains a significant cause of morbidity and mortality in preterm infants. Formula feeding is a risk factor for NEC and osmolality, which is increased by the fortification that is required for adequate growth of the infant, has been suggested as a potential cause. Our laboratory has shown that Paneth cell disruption followed by induction of dysbiosis can induce NEC-like pathology in the absence of feeds. We hypothesized adding formula feeds to the model would exacerbate intestinal injury and inflammation in an osmolality-dependent manner. NEC-like injury was induced in 14-16 day-old C57Bl/6J mice by Paneth cell disruption with dithizone or diphtheria toxin, followed by feeding rodent milk substitute with varying osmolality (250-1491 mOsm/kg H2O). Animal weight, serum cytokines and osmolality, small intestinal injury, and cecal microbial composition were quantified. Paneth cell-disrupted mice fed formula had significant NEC scores compared to controls and no longer required induction of bacterial dysbiosis. Significant increases in serum inflammatory markers, small intestinal damage, and overall mortality were osmolality-dependent and not related to microbial changes. Overall, formula feeding in combination with Paneth cell disruption induced NEC-like injury in an osmolality-dependent manner, emphasizing the importance of vigilance in designing preterm infant feeds.
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181
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Freshwater Cyanobacterium Synechococcus elongatus PCC 7942 Adapts to an Environment with Salt Stress via Ion-Induced Enzymatic Balance of Compatible Solutes. Appl Environ Microbiol 2020; 86:AEM.02904-19. [PMID: 31953341 DOI: 10.1128/aem.02904-19] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 01/12/2020] [Indexed: 11/20/2022] Open
Abstract
Salinity is one of the most important abiotic factors in various natural habitats of microbes. Cyanobacteria are the most widely distributed family of photosynthetic microorganisms in environments with fluctuating salinity. In response to salt stress, many cyanobacteria de novo synthesize compatible solutes to maintain osmotic balance in the cell. However, the regulation of intracellular accumulation of these compounds is still not well understood. The freshwater cyanobacterium Synechococcus elongatus PCC 7942 (Syn7942) exclusively accumulates sucrose as a compatible solute upon salt stress and is thus an ideal model microorganism for studying the metabolism of compatible solute dynamics. Here, we focused on elucidating the regulatory mechanisms involved in salt-induced sucrose accumulation in Syn7942. Using a series of physiological and biochemical experiments, we showed that the ionic effect of salt stress plays an important role in inducing sucrose synthesis, whereby elevated ion concentration directly activates the sucrose-synthesizing enzyme sucrose-phosphate synthase and simultaneously inhibits the sucrose-degrading enzyme invertase, resulting in a rapid sucrose accumulation. Thus, we propose a novel mechanism for cyanobacterial adaption to salt stress and fluctuating salinity, i.e., the ion-induced synergistic modulation of the enzymes synthesizing and degrading compatible solutes. These findings greatly enhance our current understanding of microbial adaptation to salt.IMPORTANCE Most microbes de novo synthesize compatible solutes for adaptation to salt stress or fluctuating salinity environments. However, to date, one of the core questions involved in these physiological processes, i.e., the regulation of salt-induced compatible solute biosynthesis, is still not well understood. Here, this issue was systematically investigated by employing the model freshwater cyanobacterium Synechococcus elongatus PCC 7942. A novel mechanism for cyanobacterial adaption to salt stress and fluctuating salinity, i.e., the ion-induced synergistic modulation of key synthesizing and degrading enzymes of compatible solutes, is proposed. Because the ion-induced activation/inhibition of enzymes is a fast and efficient process, it may represent a common strategy of microbes for adaptation to environments with fluctuating salinity.
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182
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Greffe VRG, Michiels J. Desiccation-induced cell damage in bacteria and the relevance for inoculant production. Appl Microbiol Biotechnol 2020; 104:3757-3770. [PMID: 32170388 DOI: 10.1007/s00253-020-10501-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 02/18/2020] [Accepted: 02/26/2020] [Indexed: 12/21/2022]
Abstract
Plant growth-promoting bacteria show great potential for use in agriculture although efficient application remains challenging to achieve. Cells often lose viability during inoculant production and application, jeopardizing the efficacy of the inoculant. Since desiccation has been documented to be the primary stress factor affecting the decrease in survival, obtaining xerotolerance in plant growth-promoting bacteria is appealing. The molecular damage that occurs by drying bacteria has been broadly investigated, although a complete view is still lacking due to the complex nature of the process. Mechanic, structural, and metabolic changes that occur as a result of water depletion may potentially afflict lethal damage to membranes, DNA, and proteins. Bacteria respond to these harsh conditions by increasing production of exopolysaccharides, changing composition of the membrane, improving the stability of proteins, reducing oxidative stress, and repairing DNA damage. This review provides insight into the complex nature of desiccation stress in bacteria in order to facilitate strategic choices to improve survival and shelf life of newly developed inoculants. KEY POINTS: Desiccation-induced damage affects most major macromolecules in bacteria. Most bacteria are not xerotolerant despite multiple endogenous adaption mechanisms. Sensitivity to drying severely hampers inoculant quality.
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Affiliation(s)
- Vincent Robert Guy Greffe
- Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium.,VIB Center for Microbiology, Flanders Institute for Biotechnology, Leuven, Belgium
| | - Jan Michiels
- Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium. .,VIB Center for Microbiology, Flanders Institute for Biotechnology, Leuven, Belgium.
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183
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Abdollahnia M, Makhdoumi A, Mashreghi M, Eshghi H. Exploring the potentials of halophilic prokaryotes from a solar saltern for synthesizing nanoparticles: The case of silver and selenium. PLoS One 2020; 15:e0229886. [PMID: 32130283 PMCID: PMC7055902 DOI: 10.1371/journal.pone.0229886] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 02/18/2020] [Indexed: 11/18/2022] Open
Abstract
Halophiles are the organisms that thrive in extreme high salt environments. Despite the extensive studies on their biotechnological potentials, the ability of halophilic prokaryotes for the synthesis of nanoparticles has remained understudied. In this study, the archaeal and bacterial halophiles from a solar saltern were investigated for the intracellular/extracellular synthesis of silver and selenium nanoparticles. Silver nanoparticles were produced by the archaeal Haloferax sp. (AgNP-A, intracellular) and the bacterial Halomonas sp. (AgNP-B, extracellular), while the intracellular selenium nanoparticles were produced by the archaeal Halogeometricum sp. (SeNP-A) and the bacterial Bacillus sp. (SeNP-B). The nanoparticles were characterized by various techniques including UV-Vis spectroscopy, XRD, DLS, ICP-OES, Zeta potentials, FTIR, EDX, SEM, and TEM. The average particle size of AgNP-A and AgNP-B was 26.34 nm and 22 nm based on TEM analysis. Also, the characteristic Bragg peaks of face-centered cubic with crystallite domain sizes of 13.01 nm and 6.13 nm were observed in XRD analysis, respectively. Crystallographic characterization of SeNP-A and SeNP-B strains showed a hexagonal crystallite structure with domain sizes of 30.63 nm and 29.48 nm and average sizes of 111.6 nm and 141.6 nm according to TEM analysis, respectively. The polydispersity index of AgNP-A, AgNP-B, SeNP-A, and SeNP-B was determined as 0.26, 0.28, 0.27, and 0.36 and revealed high uniformity of the nanoparticles. All of the synthesized nanoparticles were stable and their zeta potentials were calculated as (mV): -33.12, -35.9, -31.2, and -29.34 for AgNP-A, AgNP-B, SeNP-A, and SeNP-B, respectively. The nanoparticles showed the antibacterial activity against various bacterial pathogens. The results of this study suggested that the (extremely) halophilic prokaryotes have great potentials for the green synthesis of nanoparticles.
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Affiliation(s)
- Maryam Abdollahnia
- Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Ali Makhdoumi
- Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Mansour Mashreghi
- Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
- Center of Nano Research, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Hossein Eshghi
- Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
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184
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A potassium chloride to glycine betaine osmoprotectant switch in the extreme halophile Halorhodospira halophila. Sci Rep 2020; 10:3383. [PMID: 32098991 PMCID: PMC7042295 DOI: 10.1038/s41598-020-59231-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 12/10/2019] [Indexed: 11/08/2022] Open
Abstract
Halophiles utilize two distinct osmoprotection strategies. The accumulation of organic compatible solutes such as glycine betaine does not perturb the functioning of cytoplasmic components, but represents a large investment of energy and carbon. KCl is an energetically attractive alternative osmoprotectant, but requires genome-wide modifications to establish a highly acidic proteome. Most extreme halophiles are optimized for the use of one of these two strategies. Here we examine the extremely halophilic Proteobacterium Halorhodospira halophila and report that medium K+ concentration dramatically alters its osmoprotectant use. When grown in hypersaline media containing substantial K+ concentrations, H. halophila accumulates molar concentrations of KCl. However, at limiting K+ concentrations the organism switches to glycine betaine as its major osmoprotectant. In contrast, the closely related organism Halorhodospira halochloris is limited to using compatible solutes. H. halophila performs both de novo synthesis and uptake of glycine betaine, matching the biosynthesis and transport systems encoded in its genome. The medium K+ concentration (~10 mM) at which the KCl to glycine betaine osmoprotectant switch in H. halophila occurs is near the K+ content of the lake from which it was isolated, supporting an ecological relevance of this osmoprotectant strategy.
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185
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Kokoulin MS, Filshtein AP, Romanenko LA, Chikalovets IV, Chernikov OV. Structure and bioactivity of sulfated α-D-mannan from marine bacterium Halomonas halocynthiae KMM 1376T. Carbohydr Polym 2020; 229:115556. [DOI: 10.1016/j.carbpol.2019.115556] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 10/26/2019] [Accepted: 10/29/2019] [Indexed: 11/29/2022]
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186
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Stress-tolerant non-conventional microbes enable next-generation chemical biosynthesis. Nat Chem Biol 2020; 16:113-121. [DOI: 10.1038/s41589-019-0452-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 12/11/2019] [Indexed: 12/13/2022]
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187
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Tan L, Shao Y, Mu G, Ning S, Shi S. Enhanced azo dye biodegradation performance and halotolerance of Candida tropicalis SYF-1 by static magnetic field (SMF). BIORESOURCE TECHNOLOGY 2020; 295:122283. [PMID: 31669874 DOI: 10.1016/j.biortech.2019.122283] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 10/01/2019] [Accepted: 10/15/2019] [Indexed: 06/10/2023]
Abstract
Enhancing Acid Red B (ARB) decolorization by growing cells of a halotolerant yeast Candida tropicalis SYF-1 with static magnetic field (SMF) was investigated. Activity of key enzymes and membrane phospholipid fatty acids (PLFAs) were analyzed for estimating the change of metabolic activity and membrane salt-stress response, respectively. Possible enhancement mechanisms were revealed through comparative transcriptome analysis. The results showed that 95.0 mT SMF enhanced ARB decolorization by growing cells of a yeast SYF-1, as well as cell growth and halotolerance capability. Activity of intracellular lignin peroxidase (LiP) and laccase (Lac) was 1.51- and 1.47-fold higher with 95.0 mT SMF than that without SMF, respectively. Unsaturation degree and chain length of dominant PLFAs was increased by 95.0 mT SMF treatment. Several functional protein encoding unigenes related to organics biodegradation, cell growth and halotolerance were 1.17- to 4.19-fold up-regulated in response to 95.0 mT SMF.
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Affiliation(s)
- Liang Tan
- School of Life Science, Liaoning Normal University, Dalian 116081, China.
| | - Yifan Shao
- School of Life Science, Liaoning Normal University, Dalian 116081, China
| | - Guangdi Mu
- School of Life Science, Liaoning Normal University, Dalian 116081, China
| | - Shuxiang Ning
- School of Life Science, Liaoning Normal University, Dalian 116081, China
| | - Shengnan Shi
- School of Life Science, Liaoning Normal University, Dalian 116081, China
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188
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Guventurk A, Ozturk D, Ozyildiz G, Ayisigi E, Guven D, Zengin GE, Tas DO, Olmez-Hanci T, Pala-Ozkok I, Yagci N, Insel G, Cokgor E. Determination of the potential of pickle wastewater as feedstock for biopolymer production. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2020; 81:21-28. [PMID: 32293585 DOI: 10.2166/wst.2020.060] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Food industry wastewater (FIWW) streams with high organic content are among the most suitable and inexpensive candidates for polyhydroxyalkanoate (PHA) biopolymer production. Due to its high organic acid content, pickle industry wastewater (PIWW), can be considered as one of the prospective alternatives to petroleum-based polymers for PHA production. In this context, this study aimed to investigate the production of PHA with enriched microbial culture using PIWW. Two laboratory scale sequencing batch reactors (SBRs) were operated under aerobic dynamic feeding conditions at a sludge retention time of 8 days, with a total cycle duration of 24 hours. SBRs were fed with peptone mixture and PIWW. In-cycle analysis and batch respirometric tests were performed to evaluate PHA storage together with biodegradation kinetics. In-cycle analysis showed that maximum PHA content was 1,820 mgCOD/L, corresponding to 44% in the biomass (ratio of chemical oxygen demand (COD) to volatile suspended solids) for PIWW. Experimental results were also confirmed with activated sludge model simulations. As for the PHA composition, hydroxybutyrate was the major fraction. Model simulations proposed a unique conversion-degradation-storage pathway for the organic acid mixture. This paper presents a novel insight for better understanding of PHA biopolymer production using high saline FIWW.
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Affiliation(s)
- Ayse Guventurk
- Faculty of Civil Engineering, Environmental Engineering Department, Istanbul Technical University, Maslak, Istanbul 34469, Turkey E-mail:
| | - Dilara Ozturk
- Faculty of Civil Engineering, Environmental Engineering Department, Istanbul Technical University, Maslak, Istanbul 34469, Turkey E-mail:
| | - Goksin Ozyildiz
- Faculty of Civil Engineering, Environmental Engineering Department, Istanbul Technical University, Maslak, Istanbul 34469, Turkey E-mail: ; Faculty of Science and Technology, Department of Chemistry, Bioscience and Environmental Engineering, University of Stavanger, Stavanger 4021, Norway
| | - Ezgi Ayisigi
- Faculty of Civil Engineering, Environmental Engineering Department, Istanbul Technical University, Maslak, Istanbul 34469, Turkey E-mail:
| | - Didem Guven
- Faculty of Civil Engineering, Applied Biopolymer and Bioplastics Production Technologies Research Center, Istanbul Technical University, Istanbul, Turkey
| | - Gulsum Emel Zengin
- Faculty of Civil Engineering, Environmental Engineering Department, Istanbul Technical University, Maslak, Istanbul 34469, Turkey E-mail:
| | - Didem Okutman Tas
- Faculty of Civil Engineering, Environmental Engineering Department, Istanbul Technical University, Maslak, Istanbul 34469, Turkey E-mail:
| | - Tugba Olmez-Hanci
- Faculty of Civil Engineering, Environmental Engineering Department, Istanbul Technical University, Maslak, Istanbul 34469, Turkey E-mail:
| | - Ilke Pala-Ozkok
- Faculty of Civil Engineering, Environmental Engineering Department, Istanbul Technical University, Maslak, Istanbul 34469, Turkey E-mail: ; Faculty of Science and Technology, Department of Chemistry, Bioscience and Environmental Engineering, University of Stavanger, Stavanger 4021, Norway
| | - Nevin Yagci
- Faculty of Civil Engineering, Environmental Engineering Department, Istanbul Technical University, Maslak, Istanbul 34469, Turkey E-mail:
| | - Güçlü Insel
- Faculty of Civil Engineering, Environmental Engineering Department, Istanbul Technical University, Maslak, Istanbul 34469, Turkey E-mail:
| | - Emine Cokgor
- Faculty of Civil Engineering, Environmental Engineering Department, Istanbul Technical University, Maslak, Istanbul 34469, Turkey E-mail:
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189
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Corral P, Amoozegar MA, Ventosa A. Halophiles and Their Biomolecules: Recent Advances and Future Applications in Biomedicine. Mar Drugs 2019; 18:md18010033. [PMID: 31906001 PMCID: PMC7024382 DOI: 10.3390/md18010033] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 12/21/2019] [Accepted: 12/28/2019] [Indexed: 12/18/2022] Open
Abstract
The organisms thriving under extreme conditions better than any other organism living on Earth, fascinate by their hostile growing parameters, physiological features, and their production of valuable bioactive metabolites. This is the case of microorganisms (bacteria, archaea, and fungi) that grow optimally at high salinities and are able to produce biomolecules of pharmaceutical interest for therapeutic applications. As along as the microbiota is being approached by massive sequencing, novel insights are revealing the environmental conditions on which the compounds are produced in the microbial community without more stress than sharing the same substratum with their peers, the salt. In this review are reported the molecules described and produced by halophilic microorganisms with a spectrum of action in vitro: antimicrobial and anticancer. The action mechanisms of these molecules, the urgent need to introduce alternative lead compounds and the current aspects on the exploitation and its limitations are discussed.
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Affiliation(s)
- Paulina Corral
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy;
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain
| | - Mohammad A. Amoozegar
- Department of Microbiology, School of Biology, College of Science, University of Tehran, Tehran 14155-6955, Iran;
| | - Antonio Ventosa
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain
- Correspondence: ; Tel.: +34-954556765
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190
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Haque RU, Paradisi F, Allers T. Haloferax volcanii for biotechnology applications: challenges, current state and perspectives. Appl Microbiol Biotechnol 2019; 104:1371-1382. [PMID: 31863144 PMCID: PMC6985049 DOI: 10.1007/s00253-019-10314-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/05/2019] [Accepted: 12/10/2019] [Indexed: 01/08/2023]
Abstract
Haloferax volcanii is an obligate halophilic archaeon with its origin in the Dead Sea. Simple laboratory culture conditions and a wide range of genetic tools have made it a model organism for studying haloarchaeal cell biology. Halophilic enzymes of potential interest to biotechnology have opened up the application of this organism in biocatalysis, bioremediation, nanobiotechnology, bioplastics and the biofuel industry. Functionally active halophilic proteins can be easily expressed in a halophilic environment, and an extensive genetic toolkit with options for regulated protein overexpression has allowed the purification of biotechnologically important enzymes from different halophiles in H. volcanii. However, corrosion mediated damage caused to stainless-steel bioreactors by high salt concentrations and a tendency to form biofilms when cultured in high volume are some of the challenges of applying H. volcanii in biotechnology. The ability to employ expressed active proteins in immobilized cells within a porous biocompatible matrix offers new avenues for exploiting H. volcanii in biotechnology. This review critically evaluates the various application potentials, challenges and toolkits available for using this extreme halophilic organism in biotechnology.
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Affiliation(s)
- R U Haque
- School of Life Sciences, Queens Medical Centre, University of Nottingham, Nottingham, NG7 2UH, UK.,School of Chemistry, University Park, University of Nottingham, Nottingham, NG7 2RD, UK.,Warwick Integrative Synthetic Biology Centre, School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry, CV4 7AL, UK
| | - F Paradisi
- School of Chemistry, University Park, University of Nottingham, Nottingham, NG7 2RD, UK.,Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012, Bern, Switzerland
| | - T Allers
- School of Life Sciences, Queens Medical Centre, University of Nottingham, Nottingham, NG7 2UH, UK.
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191
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Genome-Resolved Metagenomics Extends the Environmental Distribution of the Verrucomicrobia Phylum to the Deep Terrestrial Subsurface. mSphere 2019; 4:4/6/e00613-19. [PMID: 31852806 PMCID: PMC6920513 DOI: 10.1128/msphere.00613-19] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Verrucomicrobia phylum of bacteria is widespread in many different ecosystems; however, its role in microbial communities remains poorly understood. Verrucomicrobia are often low-abundance community members, yet previous research suggests they play a major role in organic carbon degradation. While Verrucomicrobia remain poorly represented in culture collections, numerous genomes have been reconstructed from metagenomic data sets in recent years. The study of genomes from across the phylum allows for an extensive assessment of their potential ecosystem roles. The significance of this work is (i) the recovery of a novel genus of Verrucomicrobia from 2.3 km in the subsurface with the ability to withstand the extreme conditions that characterize this environment, and (ii) the most extensive assessment of ecophysiological traits encoded by Verrucomicrobia genomes to date. We show that members of this phylum are specialist organic polymer degraders that can withstand a wider range of environmental conditions than previously thought. Bacteria of the phylum Verrucomicrobia are prevalent and are particularly common in soil and freshwater environments. Their cosmopolitan distribution and reported capacity for polysaccharide degradation suggests members of Verrucomicrobia are important contributors to carbon cycling across Earth’s ecosystems. Despite their prevalence, the Verrucomicrobia are underrepresented in isolate collections and genome databases; consequently, their ecophysiological roles may not be fully realized. Here, we expand genomic sampling of the Verrucomicrobia phylum by describing a novel genus, “Candidatus Marcellius,” belonging to the order Opitutales. “Ca. Marcellius” was recovered from a shale-derived produced fluid metagenome collected 313 days after hydraulic fracturing, the deepest environment from which a member of the Verrucomicrobia has been recovered to date. We uncover genomic attributes that may explain the capacity of this organism to inhabit a shale gas well, including the potential for utilization of organic polymers common in hydraulic fracturing fluids, nitrogen fixation, adaptation to high salinities, and adaptive immunity via CRISPR-Cas. To illuminate the phylogenetic and environmental distribution of these metabolic and adaptive traits across the Verrucomicrobia phylum, we performed a comparative genomic analysis of 31 publicly available, nearly complete Verrucomicrobia genomes. Our genomic findings extend the environmental distribution of the Verrucomicrobia 2.3 kilometers into the terrestrial subsurface. Moreover, we reveal traits widely encoded across members of the Verrucomicrobia, including the capacity to degrade hemicellulose and to adapt to physical and biological environmental perturbations, thereby contributing to the expansive habitat range reported for this phylum. IMPORTANCE The Verrucomicrobia phylum of bacteria is widespread in many different ecosystems; however, its role in microbial communities remains poorly understood. Verrucomicrobia are often low-abundance community members, yet previous research suggests they play a major role in organic carbon degradation. While Verrucomicrobia remain poorly represented in culture collections, numerous genomes have been reconstructed from metagenomic data sets in recent years. The study of genomes from across the phylum allows for an extensive assessment of their potential ecosystem roles. The significance of this work is (i) the recovery of a novel genus of Verrucomicrobia from 2.3 km in the subsurface with the ability to withstand the extreme conditions that characterize this environment, and (ii) the most extensive assessment of ecophysiological traits encoded by Verrucomicrobia genomes to date. We show that members of this phylum are specialist organic polymer degraders that can withstand a wider range of environmental conditions than previously thought.
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192
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Huan R, Huang J, Liu D, Wang M, Liu C, Zhang Y, Yi C, Xiao D, He H. Genome Sequencing of Mesonia algae K4-1 Reveals Its Adaptation to the Arctic Ocean. Front Microbiol 2019; 10:2812. [PMID: 31866978 PMCID: PMC6905171 DOI: 10.3389/fmicb.2019.02812] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Accepted: 11/20/2019] [Indexed: 12/27/2022] Open
Abstract
The special ecological environment of the Arctic has brought about a large number of salt-tolerant and psychrotolerant microorganisms. We isolated two culturable bacterial strains of the genus Mesonia; one from the Arctic ocean, Mesonia algae K4-1, and one from the tropical sea, Mesonia sp. HuA40. Our genome analysis and phenotypic experiments indicated that Mesonia algae K4-1 is a moderately halophilic and psychrophilic bacterium. Mesonia algae K4-1 can tolerate 3–14% NaCl and grow at a wide range of temperatures from 4 to 50°C. Mesonia sp. HuA40 is a mesophilic bacterium that can only grow with 3–9% NaCl. In addition, the salt adaptation strategy of Mesonia algae K4-1 accumulates organic osmolytes in the cell. RNA helicases, glutathione and organic compatible solutes may play important roles in maintaining the metabolism and physiological function of Mesonia algae K4-1 under cold stress. Moreover, the ability of Mesonia algae K4-1 to adapt to an oligotrophic marine environment is likely due to the synthesis of a large number of extracellular polysaccharides and the secretion of various families of extracellular proteases. This study systematically analyzed the relationship between genomic differentiation and environmental factors of the Mesonia genus and revealed the possible adaptation mechanism of Mesonia algae K4-1 in the extreme Arctic marine environment at the genomic level.
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Affiliation(s)
- Ran Huan
- School of Life Sciences, Central South University, Changsha, China
| | - JiaFeng Huang
- School of Life Sciences, Central South University, Changsha, China
| | - Dan Liu
- School of Life Sciences, Central South University, Changsha, China
| | - Meng Wang
- School of Life Sciences, Central South University, Changsha, China
| | - CongLing Liu
- School of Life Sciences, Central South University, Changsha, China
| | - YunQian Zhang
- School of Life Sciences, Central South University, Changsha, China
| | - CuiPing Yi
- School of Chemistry and Biological Engineering, Changsha University of Science and Technology, Changsha, China
| | - Dong Xiao
- State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, Xuzhou, China
| | - HaiLun He
- School of Life Sciences, Central South University, Changsha, China
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193
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Bokhari A, Essack M, Lafi FF, Andres-Barrao C, Jalal R, Alamoudi S, Razali R, Alzubaidy H, Shah KH, Siddique S, Bajic VB, Hirt H, Saad MM. Bioprospecting desert plant Bacillus endophytic strains for their potential to enhance plant stress tolerance. Sci Rep 2019; 9:18154. [PMID: 31796881 PMCID: PMC6890672 DOI: 10.1038/s41598-019-54685-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 11/13/2019] [Indexed: 12/13/2022] Open
Abstract
Plant growth-promoting bacteria (PGPB) are known to increase plant tolerance to several abiotic stresses, specifically those from dry and salty environments. In this study, we examined the endophyte bacterial community of five plant species growing in the Thar desert of Pakistan. Among a total of 368 culturable isolates, 58 Bacillus strains were identified from which the 16 most divergent strains were characterized for salt and heat stress resilience as well as antimicrobial and plant growth-promoting (PGP) activities. When the 16 Bacillus strains were tested on the non-host plant Arabidopsis thaliana, B. cereus PK6-15, B. subtilis PK5-26 and B. circulans PK3-109 significantly enhanced plant growth under salt stress conditions, doubling fresh weight levels when compared to uninoculated plants. B. circulans PK3-15 and PK3-109 did not promote plant growth under normal conditions, but increased plant fresh weight by more than 50% when compared to uninoculated plants under salt stress conditions, suggesting that these salt tolerant Bacillus strains exhibit PGP traits only in the presence of salt. Our data indicate that the collection of 58 plant endophytic Bacillus strains represents an important genomic resource to decipher plant growth promotion at the molecular level.
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Affiliation(s)
- Ameerah Bokhari
- King Abdullah University of Science and Technology (KAUST), Center for Desert Agriculture, Thuwal, 23955-6900, Kingdom of Saudi Arabia.,Exploration and Petroleum Engineering Center - Advanced Research Center (EXPEC ARC), Saudi Aramco, Dhahran, Saudi Arabia
| | - Magbubah Essack
- King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Feras F Lafi
- King Abdullah University of Science and Technology (KAUST), Center for Desert Agriculture, Thuwal, 23955-6900, Kingdom of Saudi Arabia.,Zayed University, College of Natural and Health Sciences, Abu-Dhabi, 144534, United Arab Emirates
| | - Cristina Andres-Barrao
- King Abdullah University of Science and Technology (KAUST), Center for Desert Agriculture, Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Rewaa Jalal
- King Abdullah University of Science and Technology (KAUST), Center for Desert Agriculture, Thuwal, 23955-6900, Kingdom of Saudi Arabia.,University of Jeddah, P-O-BOX No.80327, Jeddah, 21589, Saudi Arabia
| | - Soha Alamoudi
- King Abdulaziz University, Science and Arts College, Department of Biology, Rabigh, 21589, Kingdom of Saudi Arabia
| | - Rozaimi Razali
- King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Hanin Alzubaidy
- King Abdullah University of Science and Technology (KAUST), Center for Desert Agriculture, Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Kausar H Shah
- Bahauddin Zakariya University, Institute of Pure and Applied Biology, Multan, 60800, Pakistan
| | - Shahid Siddique
- UC Davis, Department of Entomology and Nematology, One Shields Avenue, Davis, USA
| | - Vladimir B Bajic
- King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Heribert Hirt
- King Abdullah University of Science and Technology (KAUST), Center for Desert Agriculture, Thuwal, 23955-6900, Kingdom of Saudi Arabia. .,Max F. Perutz Laboratories, University of Vienna, Dr. Bohrgasse 9, 1030, Vienna, Austria.
| | - Maged M Saad
- King Abdullah University of Science and Technology (KAUST), Center for Desert Agriculture, Thuwal, 23955-6900, Kingdom of Saudi Arabia
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194
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Ali M, Elreedy A, Ibrahim MG, Fujii M, Nakatani K, Tawfik A. Regulating acidogenesis and methanogenesis for the separated bio-generation of hydrogen and methane from saline-to-hypersaline industrial wastewater. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 250:109546. [PMID: 31545177 DOI: 10.1016/j.jenvman.2019.109546] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 07/22/2019] [Accepted: 09/06/2019] [Indexed: 06/10/2023]
Abstract
Given the limitations of acidogens and methanogens activities under saline environments, this work aims to optimize the main operational parameters affecting hydrogen and methane production from saline-to-hypersaline wastewater containing mono-ethylene glycol (MEG). MEG is the main contaminant in several saline industrial effluents. Anaerobic baffled reactor (ABR), as a multi-stage system, was used at different temperatures (i.e., 19-31 °C [ambient] and 35 °C), organic loading rates (OLRs) of 0.6-2.2 gCOD/L/d, and salinity of 5-35 gNaCl/L. Mesophilic conditions of 35 °C substantially promoted MEG biodegradability (92-98%) and hydrogen/methane productivity, even at elevated salinity. Hydrogen yield (HY) and methane yield (MY) peaked to 258 and 140 mL/gCODadd, respectively, at OLR 0.64 gCOD/L/d and salinity up to 20-25 gNaCl/L. An immobilized sludge ABR (ISABR), packed with polyurethane media, was further compared with classical ABR, resulting in 1.8-fold higher MY, at 35 gNaCl/L. Microbial analysis showed that introducing attached growth system (ISABR) substantially promoted methanogens abundance, which was dominated by genus Methanosarcina. Among bacterial genera, Acetobacterium was dominant, particularly in 1st compartment, representing MEG-degrading/salt-tolerant genus. At high salinity up to 35 gNaCl/L, the multi-phase and attached growth configuration can efficiently reduce the induced salt stress, particularly on methanogens, towards balanced and separated acidogenesis/methanogenesis. Overall, producing hydrogen and methane from anaerobic treatment of MEG-based saline wastewater is feasible at optimized parameters and configuration.
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Affiliation(s)
- Manal Ali
- Department of Civil and Environmental Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8552, Japan; Environmental Engineering Department, Egypt-Japan University of Science and Technology, Alexandria, 21934, Egypt; Civil Engineering Department, Aswan University, Aswan, 81511, Egypt
| | - Ahmed Elreedy
- Department of Civil and Environmental Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8552, Japan; Sanitary Engineering Department, Alexandria University, Alexandria, 21544, Egypt.
| | - Mona G Ibrahim
- Environmental Engineering Department, Egypt-Japan University of Science and Technology, Alexandria, 21934, Egypt; Environmental Health Department, High Institute of Public Health, Alexandria University, Alexandria, 21544, Egypt
| | - Manabu Fujii
- Department of Civil and Environmental Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8552, Japan
| | - Kota Nakatani
- Department of Civil and Environmental Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8552, Japan
| | - Ahmed Tawfik
- Water Pollution Research Department, National Research Centre, Giza, 12622, Egypt
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195
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Abstract
Despite the typical human notion that the Earth is a habitable planet, over three quarters of our planet is uninhabitable by us without assistance. The organisms that live and thrive in these “inhospitable” environments are known by the name extremophiles and are found in all Domains of Life. Despite our general lack of knowledge about them, they have already assisted humans in many ways and still have much more to give. In this review, I describe how they have adapted to live/thrive/survive in their niches, helped scientists unlock major scientific discoveries, advance the field of biotechnology, and inform us about the boundaries of Life and where we might find it in the Universe.
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Affiliation(s)
- James A Coker
- Department of Sciences, University of Maryland Global Campus, Adelphi, MD, USA
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196
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Glamoclija M, Ramirez S, Sirisena K, Widanagamage I. Subsurface Microbial Ecology at Sediment-Groundwater Interface in Sulfate-Rich Playa; White Sands National Monument, New Mexico. Front Microbiol 2019; 10:2595. [PMID: 31781077 PMCID: PMC6861310 DOI: 10.3389/fmicb.2019.02595] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 10/25/2019] [Indexed: 01/23/2023] Open
Abstract
The hypersaline sediment and groundwater of playa lake, Lake Lucero, at the White Sands National Monument in New Mexico were examined for microbial community composition, geochemical gradients, and mineralogy during the dry season along a meter and a half depth profile of the sediment vs. the groundwater interface. Lake Lucero is a highly dynamic environment, strongly characterized by the capillary action of the groundwater, the extreme seasonality of the climate, and the hypersalinity. Sediments are predominantly composed of gypsum with minor quartz, thenardite, halite, quartz, epsomite, celestine, and clays. Geochemical analysis has revealed the predominance of nitrates over ammonium in all of the analyzed samples, indicating oxygenated conditions throughout the sediment column and in groundwater. Conversely, the microbial communities are primarily aerobic, gram-negative, and are largely characterized by their survival adaptations. Halophiles and oligotrophs are ubiquitous for all the samples. The very diverse communities contain methanogens, phototrophs, heterotrophs, saprophytes, ammonia-oxidizers, sulfur-oxidizers, sulfate-reducers, iron-reducers, and nitrifiers. The microbial diversity varied significantly between groundwater and sediment samples as their temperature adaptation inferences that revealed potential psychrophiles inhabiting the groundwater and thermophiles and mesophiles being present in the sediment. The dynamism of this environment manifests in the relatively even character of the sediment hosted microbial communities, where significant taxonomic distinctions were observed. Therefore, sediment and groundwater substrates are considered as separate ecological entities. We hope that the variety of the discussed playa environments and the microorganisms may be considered a useful terrestrial analog providing valuable information to aid future astrobiological explorations.
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Affiliation(s)
- Mihaela Glamoclija
- Department of Earth and Environmental Sciences, Rutgers University, Newark, NJ, United States
| | - Steven Ramirez
- Department of Earth and Environmental Sciences, Rutgers University, Newark, NJ, United States
| | - Kosala Sirisena
- Department of Earth and Environmental Sciences, Rutgers University, Newark, NJ, United States.,Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC, United States.,Department of Environmental Technology, Faculty of Technology, University of Colombo, Colombo, Sri Lanka
| | - Inoka Widanagamage
- Department of Earth and Environmental Sciences, Rutgers University, Newark, NJ, United States.,Department of Geology and Geological Engineering, The University of Mississippi, Oxford, MS, United States
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197
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Physicochemical considerations for bottom-up synthetic biology. Emerg Top Life Sci 2019; 3:445-458. [PMID: 33523159 PMCID: PMC7289010 DOI: 10.1042/etls20190017] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/05/2019] [Accepted: 08/07/2019] [Indexed: 12/18/2022]
Abstract
The bottom-up construction of synthetic cells from molecular components is arguably one of the most challenging areas of research in the life sciences. We review the impact of confining biological systems in synthetic vesicles. Complex cell-like systems require control of the internal pH, ionic strength, (macro)molecular crowding, redox state and metabolic energy conservation. These physicochemical parameters influence protein activity and need to be maintained within limits to ensure the system remains in steady-state. We present the physicochemical considerations for building synthetic cells with dimensions ranging from the smallest prokaryotes to eukaryotic cells.
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198
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Intermediate-Salinity Systems at High Altitudes in the Peruvian Andes Unveil a High Diversity and Abundance of Bacteria and Viruses. Genes (Basel) 2019; 10:genes10110891. [PMID: 31694288 PMCID: PMC6895999 DOI: 10.3390/genes10110891] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 10/15/2019] [Accepted: 10/26/2019] [Indexed: 12/13/2022] Open
Abstract
Intermediate-salinity environments are distributed around the world. Here, we present a snapshot characterization of two Peruvian thalassohaline environments at high altitude, Maras and Acos, which provide an excellent opportunity to increase our understanding of these ecosystems. The main goal of this study was to assess the structure and functional diversity of the communities of microorganisms in an intermediate-salinity environment, and we used a metagenomic shotgun approach for this analysis. These Andean hypersaline systems exhibited high bacterial diversity and abundance of the phyla Proteobacteria, Bacteroidetes, Balneolaeota, and Actinobacteria; in contrast, Archaea from the phyla Euryarchaeota, Thaumarchaeota, and Crenarchaeota were identified in low abundance. Acos harbored a more diverse prokaryotic community and a higher number of unique species compared with Maras. In addition, we obtained the draft genomes of two bacteria, Halomonas elongata and Idiomarina loihiensis, as well as the viral genomes of Enterobacteria lambda-like phage and Halomonas elongata-like phage and 27 partial novel viral halophilic genomes. The functional metagenome annotation showed a high abundance of sequences associated with detoxification, DNA repair, cell wall and capsule formation, and nucleotide metabolism; sequences for these functions were overexpressed mainly in bacteria and also in some archaea and viruses. Thus, their metabolic profiles afford a decrease in oxidative stress as well as the assimilation of nitrogen, a critical energy source for survival. Our work represents the first microbial characterization of a community structure in samples collected from Peruvian hypersaline systems.
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199
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High ectoine production by an engineered Halomonas hydrothermalis Y2 in a reduced salinity medium. Microb Cell Fact 2019; 18:184. [PMID: 31655591 PMCID: PMC6815383 DOI: 10.1186/s12934-019-1230-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 10/11/2019] [Indexed: 12/02/2022] Open
Abstract
Background As an attracted compatible solute, 1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid (ectoine) showed great potentials in various field. However, lower productivity and high saline medium seriously hinder its wide applications. Results The entire ectoine metabolism, including pathways for ectoine synthesis and catabolism, was identified in the genome of an ectoine-excreting strain Halomonas hydrothermalis Y2. By in-frame deletion of genes encoding ectoine hydroxylase (EctD) and (or) ectoine hydrolase (DoeA) that responsible for ectoine catabolism, the pathways for ectoine utilization were disrupted and resulted in an obviously enhanced productivity. Using an optimized medium containing 100 g L−1 NaCl in a 500-mL flask, the double mutant of Y2/ΔectD/ΔdoeA synthesized 3.13 g L−1 ectoine after 30 h cultivation. This is much higher than that of the wild type strain (1.91 g L−1), and also exceeds the production of Y2/ΔectD (2.21 g L−1). The remarkably enhanced accumulation of ectoine by Y2/ΔectD/ΔdoeA implied a critical function of Doe pathway in the ectoine catabolism. Furthermore, to reduce the salinity of fermentation medium and overcome the wastewater treatment difficulty, mutants that lacking key Na+/H+ antiporter, Mrp and (or) NhaD2, were constructed based on strain Y2/ΔectD/ΔdoeA. As a result, the Mrp-deficient strain could synthesize equal amount of ectoine (around 7 g L−1 or 500 mg (g DCW) −1) in the medium containing lower concentration of NaCl. During a fed-batch fermentation process with 60 g L−1 NaCl stress, a maximum 10.5 g L−1 ectoine was accumulated by the Mrp-deficient strain, with a specific production of 765 mg (g DCW)−1 and a yield of 0.21 g g−1 monosodium glutamate. Conclusion The remarkably enhanced production of ectoine by Y2/ΔectD/ΔdoeA implied the critical function of Doe pathway in the ectoine catabolism. Moreover, the reduced salinity requirement of Mrp-deficient strain implied a feasible protocol for many compatible solute biosynthesis, i.e., by silencing some Na+/H+ antiporters in their halophilic producers and thus lowering the medium salinity.![]()
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He H, Fu L, Liu Q, Fu L, Bi N, Yang Z, Zhen Y. Community Structure, Abundance and Potential Functions of Bacteria and Archaea in the Sansha Yongle Blue Hole, Xisha, South China Sea. Front Microbiol 2019; 10:2404. [PMID: 31681249 PMCID: PMC6813542 DOI: 10.3389/fmicb.2019.02404] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 10/04/2019] [Indexed: 01/05/2023] Open
Abstract
The Sansha Yongle Blue Hole is the deepest blue hole in the world and exhibits unique environmental characteristics. In this paper, Illumina sequencing and qPCR analysis were conducted to obtain the microbial information in this special ecosystem. The results showed that the richness and diversity of bacterial communities in the hole was greater than those of archaeal communities, and bacterial and archaeal communities were dominated by Proteobacteria and Euryarchaeota, respectively. Temperature and nitrate concentration significantly contributed to the heterogeneous distribution of major bacterial clades; salinity explained most variations of the archaeal communities, but not significant. A sudden increase of bacterial 16S rRNA, archaeal 16S rRNA, ANAMMOX 16S rRNA, nirS and dsrB gene was noticed from 90 to 100 m in the hole probably due to more phytoplankton at this depth. Sulfur oxidation and nitrate reduction were the most abundant predicted ecological functions in the hole, while lots of archaea were predicted to be involved in aerobic ammonia oxidation and methanogenesis. The co-occurrence network analysis illustrated that a synergistic effect between sulfate reduction and sulfur oxidation, and between nitrogen fixation and denitrification, a certain degree of coupling between sulfur and nitrogen cycle was also observed in the hole. The comparisons of bacterial and archaeal communities between the hole and other caves in the world (or other areas of the South China Sea) suggest that similar conditions are hypothesized to give rise to similar microbial communities, and environmental conditions may contribute significantly to the bacterial and archaeal communities.
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Affiliation(s)
- Hui He
- College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Lulu Fu
- Laboratory for Marine Ecology and Environmental Science, National Laboratory for Marine Science and Technology, Qingdao, China
- Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Qian Liu
- College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Key Laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao, China
| | - Liang Fu
- Sansha Trackline Institute of Coral Reef Environment Protection, Sansha, China
| | - Naishuang Bi
- College of Marine Geosciences, Ocean University of China, Qingdao, China
| | - Zuosheng Yang
- College of Marine Geosciences, Ocean University of China, Qingdao, China
| | - Yu Zhen
- Laboratory for Marine Ecology and Environmental Science, National Laboratory for Marine Science and Technology, Qingdao, China
- Key Laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao, China
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, China
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