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Toda N, Inoue-Kashino N, Fujita H, Yoshida R, Nimura-Matsune K, Watanabe S, Kuroda A, Kashino Y, Hirota R. Cell morphology engineering enhances grazing resistance of Synechococcus elongatus PCC 7942 for non-sterile large-scale cultivation. J Biosci Bioeng 2024; 137:245-253. [PMID: 38336581 DOI: 10.1016/j.jbiosc.2024.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 01/04/2024] [Accepted: 01/04/2024] [Indexed: 02/12/2024]
Abstract
In the practical scale of cyanobacterial cultivation, the golden algae Poterioochromonas malhamensis is a well-known predator that causes devastating damage to the culture, referred to as pond crash. The establishment and maintenance of monoculture conditions are ideal for large-scale cultures. However, this is a difficult challenge because microbial contamination is unavoidable in practical-scale culture facilities. In the present study, we unexpectedly observed the pond crash phenomenon during the pilot-scale cultivation of Synechococcus elongatus PCC 7942 using a 100-L photobioreactor. This was due to the contamination with P. malhamensis, which probably originated from residual fouling. Interestingly, we found that S.elongatus PCC 7942 can alter its morphological structure when subjected to continuous grazing pressure from predators, resulting in cells that were more than 100 times longer than those of the wild-type strain. These hyper-elongated S.elongatus PCC 7942 cells had mutations in the genes encoding FtsZ or Ftn2 which are involved in bacterial cell division. Importantly, the elongated phenotype remained stable during cultivation, enabling S.elongatus PCC 7942 to thrive and resist grazing. The cultivation of the elongated S.elongatus PCC 7942 mutant strain in a 100-L pilot-scale photobioreactor under non-sterile conditions resulted in increased cyanobacterial biomass without encountering pond crash. This study demonstrates an efficient strategy for cyanobacterial cell culture in practical-scale bioreactors without the need for extensive decontamination or sterilization of the growth medium and culture facility, which can contribute to economically viable cultivation and bioprocessing of microalgae.
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Affiliation(s)
- Narumi Toda
- Unit of Biotechnology, Division of Biological and Life Sciences, Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530, Japan
| | - Natsuko Inoue-Kashino
- Graduate School of Science, University of Hyogo, 3-2-1 Koto, Kamigori, Ako-gun, Hyogo, 678-1297, Japan
| | - Hazaya Fujita
- Graduate School of Science, University of Hyogo, 3-2-1 Koto, Kamigori, Ako-gun, Hyogo, 678-1297, Japan
| | - Ryosuke Yoshida
- Unit of Biotechnology, Division of Biological and Life Sciences, Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530, Japan
| | - Kaori Nimura-Matsune
- Department of Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo, 156-8502, Japan
| | - Satoru Watanabe
- Department of Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo, 156-8502, Japan
| | - Akio Kuroda
- Unit of Biotechnology, Division of Biological and Life Sciences, Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530, Japan; Seto Inland Sea Carbon-neutral Research Center, Hiroshima University, 2445 Mukaishima-cho, Onomichi, Hiroshima 722-0073, Japan
| | - Yasuhiro Kashino
- Graduate School of Science, University of Hyogo, 3-2-1 Koto, Kamigori, Ako-gun, Hyogo, 678-1297, Japan
| | - Ryuichi Hirota
- Unit of Biotechnology, Division of Biological and Life Sciences, Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530, Japan; Seto Inland Sea Carbon-neutral Research Center, Hiroshima University, 2445 Mukaishima-cho, Onomichi, Hiroshima 722-0073, Japan.
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2
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Lee C, Han SI, Na H, Kim Z, Ahn JW, Oh B, Kim HS. Comprehensive understanding of the mutant 'giant' Arthrospira platensis developed via ultraviolet mutagenesis. FRONTIERS IN PLANT SCIENCE 2024; 15:1369976. [PMID: 38567133 PMCID: PMC10985164 DOI: 10.3389/fpls.2024.1369976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Accepted: 03/07/2024] [Indexed: 04/04/2024]
Abstract
Introduction Cyanobacteria are typically of a size that can be observed under a microscope. Here, we present cyanobacteria of a size that can be observed with the naked eye. Arthrospira platensis NCB002 strain showed differentiated morphological characteristics compared to previously reported Arthrospira spp. Methods Arthrospira platensis NCB002 was obtained by the UV irradiation of Arthrospira sp. NCB001, which was isolated from freshwater and owned by NCell Co., Ltd. A. platensis NIES-39 was obtained from the National Institute for Environmental Studies (Tsukuba, Japan). We used various analytical techniques to determine its overall characteristics. Results and discussion The draft genome of strain NCB002 consists of five contigs comprising 6,864,973 bp with a G+C content of 44.3 mol%. The strain NCB002 had an average length of 11.69 ± 1.35 mm and a maximum of 15.15 mm, which is 23.4-50.5 times longer than the length (0.3-0.5 mm) of previously known Arthrospira spp., allowing it to be harvested using a thin sieve. Transcriptome analysis revealed that these morphological differences resulted from changes in cell wall formation mechanisms and increased cell division. Our results show that NCB002 has outstanding industrial value and provides a comprehensive understanding of it.
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Affiliation(s)
- Changsu Lee
- Bio Division, NCell. Co., Ltd., Seoul, Republic of Korea
| | - Sang-Il Han
- Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea
| | - Ho Na
- Bio Division, NCell. Co., Ltd., Seoul, Republic of Korea
| | - Zun Kim
- Bio Division, NCell. Co., Ltd., Seoul, Republic of Korea
| | - Joon Woo Ahn
- Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea
| | - Byeolnim Oh
- Department of Electronic Engineering, Kwangwoon University, Seoul, Republic of Korea
| | - Hyun Soo Kim
- Department of Electronic Engineering, Kwangwoon University, Seoul, Republic of Korea
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Singh PR, Gupta A, Singh AP, Jaiswal J, Sinha RP. Effects of ultraviolet radiation on cellular functions of the cyanobacterium Synechocystis sp. PCC 6803 and its recovery under photosynthetically active radiation. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2024; 252:112866. [PMID: 38364711 DOI: 10.1016/j.jphotobiol.2024.112866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 01/27/2024] [Accepted: 02/07/2024] [Indexed: 02/18/2024]
Abstract
Cyanobacteria are photosynthetic organisms and challenged by large number of stresses, especially by ultraviolet radiation (UVR). UVR primarily impacts lipids, proteins, DNA, photosynthetic performance, which lowers the fitness and production of cyanobacteria. UVR has a catastrophic effect on cyanobacterial cells and eventually leads to cell death. UVR tolerance in the Synechocystis was poorly studied. Therefore, we irradiated Synechocystis sp. PCC 6803 to varying hours of photosynthetically active radiations (PAR), PAR + UV-A (PA), and PAR + UV-A + UV-B (PAB) for 48 h. To study the tolerance of Synechocystis sp. PCC 6803 against different UVR. The study shows that Chl a and total carotenoids content increased up to 36 h in PAR and PA, after 36 h a decrease was observed. PC increased up to 4-fold in 48 h of PA irradiation compared to 12 h. Maximum increase in ROS was observed under 48 h PAB i.e., 5.8-fold. Flowcytometry (FCM) based analysis shows that 25% of cells do not give fluorescence of Chl a and H2DCFH. In case of cell viability 10% cells were found to be non-viable in 48 h of PAB irradiance compared to 12 h. From the above study it was found that FCM-based approaches would provide a better understanding of the variations that occurred within the Synechocystis cells compared to fluorescence microscopy-based methods.
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Affiliation(s)
- Prashant R Singh
- Laboratory of Photobiology and Molecular Microbiology, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Amit Gupta
- Laboratory of Photobiology and Molecular Microbiology, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Ashish P Singh
- Laboratory of Photobiology and Molecular Microbiology, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Jyoti Jaiswal
- Laboratory of Photobiology and Molecular Microbiology, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Rajeshwar P Sinha
- Laboratory of Photobiology and Molecular Microbiology, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India.
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Parrett GA, Brones PD, Jenkins GM, Mounts SM, Nguyen A, Risser DD. Identification of a morphogene required for tapered filament termini in filamentous cyanobacteria. MICROBIOLOGY (READING, ENGLAND) 2023; 169. [PMID: 37971486 DOI: 10.1099/mic.0.001416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
Although the photosynthetic cyanobacteria are monophyletic, they exhibit substantial morphological diversity across species, and even within an individual species due to phenotypic plasticity in response to life cycles and environmental signals. This is particularly prominent among the multicellular filamentous cyanobacteria. One example of this is the appearance of tapering at the filament termini. However, the morphogenes controlling this phenotype and the adaptive function of this morphology are not well defined. Here, using the model filamentous cyanobacterium Nostoc punctiforme ATCC29133 (PCC73102), we identify tftA, a morphogene required for the development of tapered filament termini. The tftA gene is specifically expressed in developing hormogonia, motile trichomes where the tapered filament morphology is observed, and encodes a protein containing putative amidase_3 and glucosaminidase domains, implying a function in peptidoglycan hydrolysis. Deletion of tftA abolished filament tapering inidcating that TftA plays a role in remodelling the cell wall to produce tapered filaments. Genomic conservation of tftA specifically in filamentous cyanobacteria indicates this is likely to be a conserved mechanism among these organisms. Finally, motility assays indicate that filaments with tapered termini migrate more efficiently through dense substratum, providing a plausible biological role for this morphology.
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Affiliation(s)
- Gabriel A Parrett
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO 80918, USA
| | - Peyton D Brones
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO 80918, USA
| | - Garrett M Jenkins
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO 80918, USA
| | - Savanna M Mounts
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO 80918, USA
| | - Alicia Nguyen
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO 80918, USA
| | - Douglas D Risser
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO 80918, USA
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5
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Whitman BT, Wang Y, Murray CRA, Glover MJN, Owttrim GW. Liquid-Liquid Phase Separation of the DEAD-Box Cyanobacterial RNA Helicase Redox (CrhR) into Dynamic Membraneless Organelles in Synechocystis sp. Strain PCC 6803. Appl Environ Microbiol 2023; 89:e0001523. [PMID: 36920190 PMCID: PMC10132119 DOI: 10.1128/aem.00015-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 02/17/2023] [Indexed: 03/16/2023] Open
Abstract
Compartmentalization of macromolecules into discrete non-lipid-bound bodies by liquid-liquid phase separation (LLPS) is a well-characterized regulatory mechanism frequently associated with the cellular stress response in eukaryotes. In contrast, the formation and importance of similar complexes is just becoming evident in bacteria. Here, we identify LLPS as the mechanism by which the DEAD-box RNA helicase, cyanobacterial RNA helicase redox (CrhR), compartmentalizes into dynamic membraneless organelles in a temporal and spatial manner in response to abiotic stress in the cyanobacterium Synechocystis sp. strain PCC 6803. Stress conditions induced CrhR to form a single crescent localized exterior to the thylakoid membrane, indicating that this region is a crucial domain in the cyanobacterial stress response. These crescents rapidly dissipate upon alleviation of the stress conditions. Furthermore, CrhR aggregation was mediated by LLPS in an RNA-dependent reaction. We propose that dynamic CrhR condensation performs crucial roles in RNA metabolism, enabling rapid adaptation of the photosynthetic apparatus to environmental stresses. These results expand our understanding of the role that functional compartmentalization of RNA helicases and thus RNA processing in membraneless organelles by LLPS-mediated protein condensation performs in the bacterial response to environmental stress. IMPORTANCE Oxygen-evolving photosynthetic cyanobacteria evolved ~3 billion years ago, performing fundamental roles in the biogeochemical evolution of the early Earth and continue to perform fundamental roles in nutrient cycling and primary productivity today. The phylum consists of diverse species that flourish in heterogeneous environments. A prime driver for survival is the ability to alter photosynthetic performance in response to the shifting environmental conditions these organisms continuously encounter. This study demonstrated that diverse abiotic stresses elicit dramatic changes in localization and structural organization of the RNA helicase CrhR associated with the photosynthetic thylakoid membrane. These dynamic changes, mediated by a liquid-liquid phase separation (LLPS)-mediated mechanism, reveal a novel mechanism by which cyanobacteria can compartmentalize the activity of ribonucleoprotein complexes in membraneless organelles. The results have significant consequences for understanding bacterial adaptation and survival in response to changing environmental conditions.
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Affiliation(s)
- Brendan T. Whitman
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Yixiong Wang
- Department of Oncology, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Cameron R. A. Murray
- Department of Biochemistry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Mark J. N. Glover
- Department of Biochemistry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - George W. Owttrim
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
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Kitaguchi Y, Tei H, Uriu K. Cell size homeostasis under the circadian regulation of cell division in cyanobacteria. J Theor Biol 2022; 553:111260. [PMID: 36057343 DOI: 10.1016/j.jtbi.2022.111260] [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: 12/27/2021] [Revised: 06/10/2022] [Accepted: 08/18/2022] [Indexed: 10/31/2022]
Abstract
Bacterial cells maintain their characteristic cell size over many generations. Several rod-shaped bacteria, such as Escherichia coli and the cyanobacteria Synechococcus elongatus, divide after adding a constant length to their length at birth. Through this division control known as the adder mechanism, perturbation in cell length due to physiological fluctuation decays over generations at a rate of 2-1 per cell division. However, previous experiments have shown that the circadian clock in cyanobacteria reduces cell division frequency at a specific time of day under constant light. This circadian gating should modulate the division control by the adder mechanism, but its significance remains unknown. Here we address how the circadian gating affects cell length, doubling time, and cell length stability in cyanobacteria by using mathematical models. We show that a cell subject to circadian gating grows for a long time, and gives birth to elongated daughter cells. These elongated daughter cells grow faster than the previous generation, as elongation speed is proportional to cell length and divide in a short time before the next gating. Hence, the distributions of doubling time and cell length become bimodal, as observed in experimental data. Interestingly, the average doubling time over the population of cells is independent of gating because the extension of doubling time by gating is compensated by its reduction in the subsequent generation. On the other hand, average cell length is increased by gating, suggesting that the circadian clock controls cell length. We then show that the decay rate of perturbation in cell length depends on the ratio of delay in division by the gating τG to the average doubling time τ0 as [Formula: see text] . We estimated τG≈2.5, τ0≈13.6 hours, and τG/τ0≈0.18 from experimental data, indicating that a long doubling time in cyanobacteria maintains the decay rate similar to that of the adder mechanism. Thus, our analysis suggests that the acquisition of the circadian clock during evolution did not impose a constraint on cell size homeostasis in cyanobacteria.
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Affiliation(s)
- Yuta Kitaguchi
- Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, 920-1129, Japan.
| | - Hajime Tei
- Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, 920-1129, Japan
| | - Koichiro Uriu
- Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, 920-1129, Japan
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Yalcin YS, Aydin BN, Sayadujjhara M, Sitther V. Antibiotic-Induced Changes in Pigment Accumulation, Photosystem II, and Membrane Permeability in a Model Cyanobacterium. Front Microbiol 2022; 13:930357. [PMID: 35814666 PMCID: PMC9257187 DOI: 10.3389/fmicb.2022.930357] [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: 04/27/2022] [Accepted: 05/25/2022] [Indexed: 11/27/2022] Open
Abstract
Fremyella diplosiphon is a well-studied a model cyanobacterium for photosynthesis due to its efficient light absorption potential and pigment accumulation. In the present study, the impact of ampicillin, tetracycline, kanamycin, and cefotaxime on pigment fluorescence and photosynthetic capacity in Fremyella diplosiphon strains B481-WT and B481-SD was investigated. Our results indicated that both strains exposed to kanamycin from 0.2 to 3.2 mg/L and tetracycline from 0.8 to 12.8 mg/L enhanced growth and pigment accumulation. Additionally, B481-SD treated with 0.2–51.2 mg/L ampicillin resulted in a significant enhancement of pigment fluorescence. A detrimental effect on growth and pigmentation in both the strains exposed to 6.4–102.5 mg/L kanamycin and 0.8–102.5 mg/L cefotaxime was observed. Detection of reactive oxygen species revealed highest levels of oxidative stress at 51.2 and 102.5 mg/L kanamycin for B481-SD and 102.5 mg/L for B481-WT. Membrane permeability detected by lactate dehydrogenase assay indicated maximal activity at 0.8 mg/L ampicillin, kanamycin, and tetracycline treatments on day 6. Abundant vacuolation, pyrophosphate, and cyanophycin granule formation were observed in treated cells as a response to antibiotic stress. These findings on the hormetic effect of antibiotics on F. diplosiphon indicate that optimal antibiotic concentrations induce cellular growth while high concentrations severely impact cellular functionality. Future studies will be aimed to enhance cellular lipid productivity at optimal antibiotic concentrations to disintegrate the cell wall, thus paving the way for clean bioenergy applications.
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Xian X, Li X, Ye C, Wan K, Feng M, Luo C, Yu X. Higher sensitivity to Cu 2+ exposure of Microcystis aeruginosa in late lag phase is beneficial to its control. WATER RESEARCH 2022; 214:118207. [PMID: 35217491 DOI: 10.1016/j.watres.2022.118207] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 02/05/2022] [Accepted: 02/16/2022] [Indexed: 06/14/2023]
Abstract
Cyanobacterial blooms are always treated in exponential phase, which demands high dosages of algicides (e.g., CuSO4). Actually, cyanobacterial blooms in late lag phase exhibit low cell-density and specific physiological/biochemical characteristics, implying the possibility of controlling blooms in a more efficient and economical way with CuSO4 treatment if cyanobacterial cells in late lag phase can be treated. In this study, the outbreakof a Microcystis bloom was simulated, and Microcystis samples in late lag and exponential phases were treated with CuSO4. The results showed that M. aeruginosa in late lag phase had a higher ratio of dividing-cells, Fv/Fm and intracellular total organic carbon content (TOC) than that in exponential phase, indicating that its metabolic activity was vigorous. M. aeruginosa in late lag phase could more easily be blocked, since a higher decrease in chlorophyll-a, Fv/Fm and membrane integrity occurred under the same dosages of CuSO4 exposure compared to M. aeruginosa in exponential phase. Meanwhile, microcystin release in late lag phase was less than that in exponential phase. Moreover, higher sensitivity in late lag phase was confirmed at the individual level, as the photosynthesis related genes psaB and rbcL were more down-regulated than those in exponential phase. In general, cyanobacteria in late lag phase exhibited higher sensitivity to CuSO4, indicating that CuSO4 treatments in late lag phase can achieve a higher control efficiency and fewer release of microcystin with low-dosages algicide. Hence, it is a more environmentally friendly strategy to control cyanobacterial blooms than the traditional strategy applied in exponential phase.
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Affiliation(s)
- Xuanxuan Xian
- College of the Environment & Ecology, Xiamen University, Xiamen 361102, China
| | - Xi Li
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Chengsong Ye
- College of the Environment & Ecology, Xiamen University, Xiamen 361102, China
| | - Kun Wan
- College of the Environment & Ecology, Xiamen University, Xiamen 361102, China
| | - Mingbao Feng
- College of the Environment & Ecology, Xiamen University, Xiamen 361102, China
| | - Chen Luo
- College of the Environment & Ecology, Xiamen University, Xiamen 361102, China
| | - Xin Yu
- College of the Environment & Ecology, Xiamen University, Xiamen 361102, China.
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Schätzle H, Arévalo S, Flores E, Schleiff E. A TonB-Like Protein, SjdR, Is Involved in the Structural Definition of the Intercellular Septa in the Heterocyst-Forming Cyanobacterium Anabaena. mBio 2021; 12:e0048321. [PMID: 34101487 PMCID: PMC8262864 DOI: 10.1128/mbio.00483-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 05/04/2021] [Indexed: 12/11/2022] Open
Abstract
Cyanobacteria are photosynthetic organisms with a Gram-negative envelope structure. Certain filamentous species such as Anabaena sp. strain PCC 7120 can fix dinitrogen upon depletion of combined nitrogen. Because the nitrogen-fixing enzyme, nitrogenase, is oxygen sensitive, photosynthesis and nitrogen fixation are spatially separated in Anabaena. Nitrogen fixation takes place in specialized cells called heterocysts, which differentiate from vegetative cells. During heterocyst differentiation, a microoxic environment is created by dismantling photosystem II and restructuring the cell wall. Moreover, solute exchange between the different cell types is regulated to limit oxygen influx into the heterocyst. The septal zone containing nanopores for solute exchange is constricted between heterocysts and vegetative cells, and cyanophycin plugs are located at the heterocyst poles. We identified a protein previously annotated as TonB1 that is largely conserved among cyanobacteria. A mutant of the encoding gene formed heterocysts but was impaired in diazotrophic growth. Mutant heterocysts appeared elongated and exhibited abnormal morphological features, including a reduced cyanophycin plug, an enhanced septum size, and a restricted nanopore zone in the septum. In spite of this, the intercellular transfer velocity of the fluorescent marker calcein was increased in the mutant compared to the wild type. Thus, the protein is required for proper formation of septal structures, expanding our emerging understanding of Anabaena peptidoglycan plasticity and intercellular solute exchange, and is therefore renamed SjdR (septal junction disk regulator). Notably, calcium supplementation compensated for the impaired diazotrophic growth and alterations in septal peptidoglycan in the sjdR mutant, emphasizing the importance of calcium for cell wall structure. IMPORTANCE Multicellularity in bacteria confers an improved adaptive capacity to environmental conditions and stresses. This includes an enhanced capability of resource utilization through a distribution of biochemical processes between constituent cells. This specialization results in a mutual dependency of different cell types, as is the case for nitrogen-fixing heterocysts and photosynthetically active vegetative cells in Anabaena. In this cyanobacterium, intercellular solute exchange is facilitated through nanopores in the peptidoglycan between adjacent cells. To ensure functionality of the specialized cells, septal size as well as the position, size, and frequency of nanopores in the septum need to be tightly established. The novel septal junction disk regulator SjdR characterized here is conserved in the cyanobacterial phylum. It influences septal size and septal nanopore distribution. Consequently, its absence severely affects the intercellular communication and the strains' growth capacity under nitrogen depletion. Thus, SjdR is involved in septal structure remodeling in cyanobacteria.
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Affiliation(s)
- Hannah Schätzle
- Institute for Molecular Biosciences, Goethe University Frankfurt, Frankfurt am Main, Germany
- FIERCE, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Sergio Arévalo
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Seville, Spain
| | - Enrique Flores
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Seville, Spain
| | - Enrico Schleiff
- Institute for Molecular Biosciences, Goethe University Frankfurt, Frankfurt am Main, Germany
- FIERCE, Goethe University Frankfurt, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences, Frankfurt am Main, Germany
- Frankfurt Institute for Advanced Studies, Frankfurt am Main, Germany
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10
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Jung CHG, Braune S, Waldeck P, Küpper JH, Petrick I, Jung F. Morphology and Growth of Arthrospira platensis during Cultivation in a Flat-Type Bioreactor. Life (Basel) 2021; 11:life11060536. [PMID: 34207508 PMCID: PMC8229077 DOI: 10.3390/life11060536] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/26/2021] [Accepted: 06/01/2021] [Indexed: 01/09/2023] Open
Abstract
Arthrospira platensis (AP) is a cyanobacterium with a high economic value and is nowadays one of the most important industrially cultivated microalgae. Knowledge of its growth is essential for the understanding of its physiology and yield. The growth of AP biomass occurs through two mechanisms: (1) propagation by fragmentation of trichomes, and (2) the trichomes are extended by binary fission until they reach their mature status. These phases are visualized by live cell light and laser scanning microscopy, demonstrating the different phases of AP growth.
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Affiliation(s)
- Conrad H. G. Jung
- Carbon Biotech Social Enterprise AG, 01968 Senftenberg, Germany; (C.H.G.J.); (J.-H.K.)
| | - Steffen Braune
- Institute of Biotechnology, Molecular Cell Biology, Brandenburg University of Technology Cottbus-Senftenberg, 01968 Senftenberg, Germany;
| | - Peter Waldeck
- Institute of Materials Chemistry, Thermodynamics, Brandenburg University of Technology Cottbus-Senftenberg, 01968 Senftenberg, Germany; (P.W.); (I.P.)
| | - Jan-Heiner Küpper
- Carbon Biotech Social Enterprise AG, 01968 Senftenberg, Germany; (C.H.G.J.); (J.-H.K.)
- Institute of Biotechnology, Molecular Cell Biology, Brandenburg University of Technology Cottbus-Senftenberg, 01968 Senftenberg, Germany;
| | - Ingolf Petrick
- Institute of Materials Chemistry, Thermodynamics, Brandenburg University of Technology Cottbus-Senftenberg, 01968 Senftenberg, Germany; (P.W.); (I.P.)
| | - Friedrich Jung
- Institute of Biotechnology, Molecular Cell Biology, Brandenburg University of Technology Cottbus-Senftenberg, 01968 Senftenberg, Germany;
- Correspondence:
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11
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Pagels F, Vasconcelos V, Guedes AC. Carotenoids from Cyanobacteria: Biotechnological Potential and Optimization Strategies. Biomolecules 2021; 11:biom11050735. [PMID: 34063485 PMCID: PMC8156961 DOI: 10.3390/biom11050735] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/11/2021] [Accepted: 05/12/2021] [Indexed: 12/16/2022] Open
Abstract
Carotenoids are tetraterpenoids molecules present in all photosynthetic organisms, responsible for better light-harvesting and energy dissipation in photosynthesis. In cyanobacteria, the biosynthetic pathway of carotenoids is well described, and apart from the more common compounds (e.g., β-carotene, zeaxanthin, and echinenone), specific carotenoids can also be found, such as myxoxanthophyll. Moreover, cyanobacteria have a protein complex called orange carotenoid protein (OCP) as a mechanism of photoprotection. Although cyanobacteria are not the organism of choice for the industrial production of carotenoids, the optimisation of their production and the evaluation of their bioactive capacity demonstrate that these organisms may indeed be a potential candidate for future pigment production in a more environmentally friendly and sustainable approach of biorefinery. Carotenoids-rich extracts are described as antioxidant, anti-inflammatory, and anti-tumoral agents and are proposed for feed and cosmetical industries. Thus, several strategies for the optimisation of a cyanobacteria-based bioprocess for the obtention of pigments were described. This review aims to give an overview of carotenoids from cyanobacteria not only in terms of their chemistry but also in terms of their biotechnological applicability and the advances and the challenges in the production of such compounds.
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Affiliation(s)
- Fernando Pagels
- CIIMAR—Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Novo Edifício do Terminal de Cruzeiros de Leixões, Avenida General Norton de Matos, s/n, 4450-208 Matosinhos, Portugal; (F.P.); (V.V.)
- FCUP—Faculty of Science, University of Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal
| | - Vitor Vasconcelos
- CIIMAR—Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Novo Edifício do Terminal de Cruzeiros de Leixões, Avenida General Norton de Matos, s/n, 4450-208 Matosinhos, Portugal; (F.P.); (V.V.)
- FCUP—Faculty of Science, University of Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal
| | - Ana Catarina Guedes
- CIIMAR—Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Novo Edifício do Terminal de Cruzeiros de Leixões, Avenida General Norton de Matos, s/n, 4450-208 Matosinhos, Portugal; (F.P.); (V.V.)
- Correspondence:
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Genetic, Genomics, and Responses to Stresses in Cyanobacteria: Biotechnological Implications. Genes (Basel) 2021; 12:genes12040500. [PMID: 33805386 PMCID: PMC8066212 DOI: 10.3390/genes12040500] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/25/2021] [Accepted: 03/25/2021] [Indexed: 02/07/2023] Open
Abstract
Cyanobacteria are widely-diverse, environmentally crucial photosynthetic prokaryotes of great interests for basic and applied science. Work to date has focused mostly on the three non-nitrogen fixing unicellular species Synechocystis PCC 6803, Synechococcus PCC 7942, and Synechococcus PCC 7002, which have been selected for their genetic and physiological interests summarized in this review. Extensive "omics" data sets have been generated, and genome-scale models (GSM) have been developed for the rational engineering of these cyanobacteria for biotechnological purposes. We presently discuss what should be done to improve our understanding of the genotype-phenotype relationships of these models and generate robust and predictive models of their metabolism. Furthermore, we also emphasize that because Synechocystis PCC 6803, Synechococcus PCC 7942, and Synechococcus PCC 7002 represent only a limited part of the wide biodiversity of cyanobacteria, other species distantly related to these three models, should be studied. Finally, we highlight the need to strengthen the communication between academic researchers, who know well cyanobacteria and can engineer them for biotechnological purposes, but have a limited access to large photobioreactors, and industrial partners who attempt to use natural or engineered cyanobacteria to produce interesting chemicals at reasonable costs, but may lack knowledge on cyanobacterial physiology and metabolism.
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13
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Cellular and Molecular Strategies in Cyanobacterial Survival-"In Memory of Prof. Dr. Wolfgang Lockau". Life (Basel) 2021; 11:life11020132. [PMID: 33572088 PMCID: PMC7915015 DOI: 10.3390/life11020132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 02/04/2021] [Indexed: 12/20/2022] Open
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