1
|
Victoria AJ, Selão TT, Moreno-Cabezuelo JÁ, Mills LA, Gale GAR, Lea-Smith DJ, McCormick AJ. A toolbox to engineer the highly productive cyanobacterium Synechococcus sp. PCC 11901. PLANT PHYSIOLOGY 2024; 196:1674-1690. [PMID: 38713768 PMCID: PMC11444289 DOI: 10.1093/plphys/kiae261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 04/09/2024] [Accepted: 04/14/2024] [Indexed: 05/09/2024]
Abstract
Synechococcus sp. PCC 11901 (PCC 11901) is a fast-growing marine cyanobacterial strain that has a capacity for sustained biomass accumulation to very high cell densities, comparable to that achieved by commercially relevant heterotrophic organisms. However, genetic tools to engineer PCC 11901 for biotechnology applications are limited. Here we describe a suite of tools based on the CyanoGate MoClo system to unlock the engineering potential of PCC 11901. First, we characterized neutral sites suitable for stable genomic integration that do not affect growth even at high cell densities. Second, we tested a suite of constitutive promoters, terminators, and inducible promoters including a 2,4-diacetylphloroglucinol (DAPG)-inducible PhlF repressor system, which has not previously been demonstrated in cyanobacteria and showed tight regulation and a 228-fold dynamic range of induction. Lastly, we developed a DAPG-inducible dCas9-based CRISPR interference (CRISPRi) system and a modular method to generate markerless mutants using CRISPR-Cas12a. Based on our findings, PCC 11901 is highly responsive to CRISPRi-based repression and showed high efficiencies for single insertion (31% to 81%) and multiplex double insertion (25%) genome editing with Cas12a. We envision that these tools will lay the foundations for the adoption of PCC 11901 as a robust model strain for engineering biology and green biotechnology.
Collapse
Affiliation(s)
- Angelo J Victoria
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
- Centre for Engineering Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Tiago Toscano Selão
- Department of Chemical and Environmental Engineering, University of Nottingham, Nottingham NG7 2RD, UK
| | | | - Lauren A Mills
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Grant A R Gale
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
- Centre for Engineering Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - David J Lea-Smith
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Alistair J McCormick
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
- Centre for Engineering Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| |
Collapse
|
2
|
Koga T, Hirakawa S, Nakagawa S, Ishibashi Y, Kashiwabara M, Miyawaki T. Systematization of a toxicity screening method based on a combination of chemical analysis and the delayed fluorescence algal growth inhibition test for use in emergency environmental surveys. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:55447-55461. [PMID: 39230813 DOI: 10.1007/s11356-024-34821-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Accepted: 08/23/2024] [Indexed: 09/05/2024]
Abstract
In recent years, heavy rainfall disasters linked to climate change have become more frequent, raising concerns about the release of chemicals stored in factories. Assessing chemical contamination during such emergencies therefore necessitates the development of a quick and easy method for evaluating hazardous contaminants in combination with toxicity testing. This study proposes a "toxicity screening" method that combines biological response testing and chemical analysis to systematically evaluate hazardous contaminants in emergency situations. The toxicity screening method evaluates the water quality in three steps, including water quality measurements and a delayed fluorescence (DF) assay, metal content measurements and a DF assay, and targeted screening analysis and a DF assay. The efficacy of this method was tested using industrial wastewater from 14 locations. Seven of the samples were non-toxic, while the other seven samples were toxic, displaying no observed effect concentration (NOEC) values ranging from 0.625 to 20%. Two toxic samples in the first phase possessed high total chlorine concentrations (0.4 mg L-1) and conductivities (2200 mS m-1), indicating that the main sources of toxicity were residual chlorine and a high salt concentration. In the second phase, metal content analysis identified metals as the toxicity cause in four samples. In the third phase, the organic contaminants were analyzed, and tri-n-octyl phosphate (TNOP) was detected at a concentration of 0.00027 mg L-1. The results of solid-phase extraction experiments and exposure tests with TNOP alone indicated that the contribution of TNOP to the toxicity was negligible and that chemicals not adsorbed on the solid-phase extraction cartridges were the cause of toxicity. The proposed method can therefore be considered effective for disaster-related water quality assessment, delivering results within 12 days.
Collapse
Affiliation(s)
- Toyokazu Koga
- Fukuoka Prefectural Institute of Health and Environmental Sciences, 39 Mukaisano, Dazaifu, Fukuoka, 818-0135, Japan.
| | - Shusaku Hirakawa
- Fukuoka Prefectural Institute of Health and Environmental Sciences, 39 Mukaisano, Dazaifu, Fukuoka, 818-0135, Japan
| | - Shuhei Nakagawa
- Fukuoka Prefectural Institute of Health and Environmental Sciences, 39 Mukaisano, Dazaifu, Fukuoka, 818-0135, Japan
| | - Yuko Ishibashi
- Fukuoka Prefectural Institute of Health and Environmental Sciences, 39 Mukaisano, Dazaifu, Fukuoka, 818-0135, Japan
| | - Manabu Kashiwabara
- Fukuoka Research Commercialization Center for Recycling Systems, 2-1 Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka, 808-0135, Japan
| | - Takashi Miyawaki
- The University of Kitakyushu, 1-1 Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka, 808-0135, Japan
| |
Collapse
|
3
|
Gao S, Pittman K, Edmundson S, Huesemann M, Greer M, Louie W, Chen P, Nobles D, Benemann J, Crowe B. A newly isolated alkaliphilic cyanobacterium for biomass production with direct air CO2 capture. J CO2 UTIL 2023. [DOI: 10.1016/j.jcou.2023.102399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
|
4
|
Cheng J, Zhang K, Li J, Hou Y. Using δF IP as a potential biomarker for risk assessment of environmental pollutants in aquatic ecosystem: A case study of marine cyanobacterium Synechococcus sp. PCC7002. CHEMOSPHERE 2023; 313:137621. [PMID: 36566796 DOI: 10.1016/j.chemosphere.2022.137621] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 12/19/2022] [Accepted: 12/20/2022] [Indexed: 06/17/2023]
Abstract
Increased hazardous substances application causes more environmental pollution and risks for human health. Microalgae are the important biological groups in marine ecosystem, and considered to be sensitive to environmental pollutants. Therefore, toxicity test on marine microalgae could provide the most efficient method for aquatic toxicity assessment, and could also be used as the early warning signals in aquatic ecosystem. In view of this, our study aimed at investigating the toxicity potential of two typical organic compounds, and screening out novel photosynthetic indicators for the risk assessment of environmental pollutants. In this study, benzyl alcohol and 2-phenylethanol were chosen as the target organic compounds, and preliminary toxicity mechanism of these organic compounds on marine cyanobacterium Synechococcus sp. PCC7002 was investigated with chlorophyll fluorescence technology. Results showed that PCC7002 could be affected by benzyl alcohol or 2-phenylethanol stress, and the toxicity effect was concentration-dependent. And external benzyl alcohol and 2-phenylethanol stress damaged the oxygen evolving complex, and suppressed electron transport at the donor and receptor sides of photosystem II (PSII), influencing the absorption, transfer, and application of light energy. Furthermore, potential biomarkers were screened by half maximal inhibitory concentration (IC50) on the basis of pearson correlation coefficient analysis, and fluorescence intensity difference between the I-step and P-step of OJIP curve (δFIP) seems to be the most sensitive indicator for external stress. This study would be of significant interest to the biomarker community, and pave the way for the practical resource for marine pollution monitoring and assessment.
Collapse
Affiliation(s)
- Jie Cheng
- School of Life Sciences, Liaocheng University, Liaocheng, 252000, China; State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China.
| | - Kaidian Zhang
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan Aquaculture Breeding Engineering Research Center, Hainan University, Haikou, 570100, China; State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China
| | - Jiashun Li
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China
| | - Yuyong Hou
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.
| |
Collapse
|
5
|
Development of shuttle vectors for rapid prototyping of engineered Synechococcus sp. PCC7002. Appl Microbiol Biotechnol 2022; 106:8169-8181. [PMID: 36401644 DOI: 10.1007/s00253-022-12289-z] [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: 04/21/2022] [Revised: 09/18/2022] [Accepted: 11/11/2022] [Indexed: 11/20/2022]
Abstract
Cyanobacteria are of particular interest for chemical production as they can assimilate CO2 and use solar energy to power chemical synthesis. However, unlike the model microorganism of Escherichia coli, the availability of genetic toolboxes for rapid proof-of-concept studies in cyanobacteria is generally lacking. In this study, we first characterized a set of promoters to efficiently drive gene expressions in the marine cyanobacterium Synechococcus sp. PCC7002. We identified that the endogenous cpcBA promoter represented one of the strongest promoters in PCC7002. Next, a set of shuttle vectors was constructed based on the endogenous pAQ1 plasmid to facilitate the rapid pathway assembly. Moreover, we used the shuttle vectors to modularly optimize the amorpha-4,11-diene synthesis in PCC7002. By modularly optimizing the metabolic pathway, we managed to redistribute the central metabolism toward the amorpha-4,11-diene production in PCC7002 with enhanced product titer. Taken together, the plasmid toolbox developed in this study will greatly accelerate the generation of genetically engineered PCC7002. KEY POINTS: • Promoter characterization revealed that the endogenous cpcBA promoter represented one of the strongest promoters in PCC7002 • A set of shuttle vectors with different antibiotic selection markers was constructed based on endogenous pAQ1 plasmid • By modularly optimizing the metabolic pathway, amorpha-4,11-diene production in PCC7002 was improved.
Collapse
|
6
|
Oxygen stress mitigation for microalgal biomass productivity improvement in outdoor raceway ponds. ALGAL RES 2022. [DOI: 10.1016/j.algal.2022.102901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
|
7
|
Hills KA, Hyne RV, Kefford BJ. Bicarbonate alone does not totally explain the toxicity from major ions of coal bed derived waters to freshwater invertebrates. ECOTOXICOLOGY (LONDON, ENGLAND) 2022; 31:967-975. [PMID: 35701565 PMCID: PMC9300549 DOI: 10.1007/s10646-022-02552-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 04/27/2022] [Indexed: 06/15/2023]
Abstract
Concentrations of major ions in coal mine discharge waters and unconventional hydrocarbon produced waters derived from coal bed methane (CBM) production, are potentially harmful to freshwater ecosystems. Bicarbonate is a major constituent of produced waters from CBM and coal mining. However, little is known about the relative toxicity of differing ionic proportions, especially bicarbonate, found in these CBM waters. As all freshwater invertebrates tested are more acutely sensitive to sodium bicarbonate (NaHCO3) than sodium chloride (NaCl) or synthetic sea water, we tested the hypotheses that toxicity of CBM waters are driven by bicarbonate concentration, and waters containing a higher proportion of bicarbonate are more toxic to freshwater invertebrates than those with less bicarbonate. We compared the acute (96 h) lethal toxicity to six freshwater invertebrate species of NaHCO3 and two synthetic CBM waters, with ionic proportions representative of water from CBM wells across New South Wales (NSW) and Queensland (Qld), in Australia. The ranking of LC50 values expressed as total salinity was consistent with the hypotheses. However, when toxicity was expressed as bicarbonate concentration, the hypothesis that the toxicity of coal bed waters would be explained by bicarbonate concentration was not well supported, and other ionic components were either ameliorating or exacerbating the NaHCO3 toxicity. Our findings showed NaHCO3 was more toxic than NaCl and that the NaHCO3 proportion of synthetic CBM waters drives toxicity, however other ions are altering the toxicity of bicarbonate.
Collapse
Affiliation(s)
- Kasey A Hills
- Centre for Applied Water Sciences, Institute for Applied Ecology, University of Canberra, Bruce, ACT, 2601, Australia
- New South Wales Environmental Protection Authority, Locked Bag 5022, Parramatta, NSW, 2124, Australia
| | - Ross V Hyne
- Department of Planning, Industry and Environment, Environment Protection Science, Lidcombe Laboratories, Lidcombe, NSW, 2141, Australia
| | - Ben J Kefford
- Centre for Applied Water Sciences, Institute for Applied Ecology, University of Canberra, Bruce, ACT, 2601, Australia.
| |
Collapse
|
8
|
Dev Sarkar R, Singh HB, Chandra Kalita M. Enhanced lipid accumulation in microalgae through nanoparticle-mediated approach, for biodiesel production: A mini-review. Heliyon 2021; 7:e08057. [PMID: 34622062 PMCID: PMC8481968 DOI: 10.1016/j.heliyon.2021.e08057] [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: 07/01/2021] [Revised: 07/02/2021] [Accepted: 09/20/2021] [Indexed: 12/11/2022] Open
Abstract
Nanoparticle application in microalgae for enhanced lipid production is an ongoing work that leads towards the contribution in biodiesel production. During this decade, metal nanoparticles are constantly being reported to have numerous applications in diverse fields, because of their unique optical, electrical, and magnetic properties. They can interact with the biomolecules of cells and thereby alters cellular metabolisms, which in turn reflects their ability to regulate some primary or secondary metabolic pathways. Nanoparticles derived from metals like Fe, Cu, and Se are taking part in redox processes and their presence in many enzymes may modulate algal metabolisms. Besides by upregulating or downregulating the expression of several genes, nanoparticle exposure can alter gene expressions in many organisms. In microalgae such as Chlorella vulgaris, C. pyrenoidosa, Scenedesmus obliquus, S. rubescens, Trachydiscus minut u s, Parachlorella kessleri, and Tetraselmis suecica; metal nanoparticle exposure in different environmental conditions have impacts on various physiological or molecular changes, thereby increasing the growth rate, biomass and lipid production. The present mini-review gives an insight into the various advantages and a future outlook on the application of nanoparticles in microalgae for biofuel production. Also, it can be proposed that nanoparticles could be useful in blocking or deactivating the AGPase enzyme (involved in the glucose to starch conversion pathway), binding to its active site, thereby increasing lipid production in microalgae that could be utilized for enhanced biodiesel production.
Collapse
|
9
|
A Genome-Scale Metabolic Model of Anabaena 33047 to Guide Genetic Modifications to Overproduce Nylon Monomers. Metabolites 2021; 11:metabo11030168. [PMID: 33804103 PMCID: PMC7999273 DOI: 10.3390/metabo11030168] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/04/2021] [Accepted: 03/11/2021] [Indexed: 11/17/2022] Open
Abstract
Nitrogen fixing-cyanobacteria can significantly improve the economic feasibility of cyanobacterial production processes by eliminating the requirement for reduced nitrogen. Anabaena sp. ATCC 33047 is a marine, heterocyst forming, nitrogen fixing cyanobacteria with a very short doubling time of 3.8 h. We developed a comprehensive genome-scale metabolic (GSM) model, iAnC892, for this organism using annotations and content obtained from multiple databases. iAnC892 describes both the vegetative and heterocyst cell types found in the filaments of Anabaena sp. ATCC 33047. iAnC892 includes 953 unique reactions and accounts for the annotation of 892 genes. Comparison of iAnC892 reaction content with the GSM of Anabaena sp. PCC 7120 revealed that there are 109 reactions including uptake hydrogenase, pyruvate decarboxylase, and pyruvate-formate lyase unique to iAnC892. iAnC892 enabled the analysis of energy production pathways in the heterocyst by allowing the cell specific deactivation of light dependent electron transport chain and glucose-6-phosphate metabolizing pathways. The analysis revealed the importance of light dependent electron transport in generating ATP and NADPH at the required ratio for optimal N2 fixation. When used alongside the strain design algorithm, OptForce, iAnC892 recapitulated several of the experimentally successful genetic intervention strategies that over produced valerolactam and caprolactam precursors.
Collapse
|
10
|
Newly discovered Synechococcus sp. PCC 11901 is a robust cyanobacterial strain for high biomass production. Commun Biol 2020; 3:215. [PMID: 32382027 PMCID: PMC7205611 DOI: 10.1038/s42003-020-0910-8] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 03/16/2020] [Indexed: 12/31/2022] Open
Abstract
Cyanobacteria, which use solar energy to convert carbon dioxide into biomass, are potential solar biorefineries for the sustainable production of chemicals and biofuels. However, yields obtained with current strains are still uncompetitive compared to existing heterotrophic production systems. Here we report the discovery and characterization of a new cyanobacterial strain, Synechococcus sp. PCC 11901, with promising features for green biotechnology. It is naturally transformable, has a short doubling time of ≈2 hours, grows at high light intensities and in a wide range of salinities and accumulates up to ≈33 g dry cell weight per litre when cultured in a shake-flask system using a modified growth medium − 1.7 to 3 times more than other strains tested under similar conditions. As a proof of principle, PCC 11901 engineered to produce free fatty acids yielded over 6 mM (1.5 g L−1), an amount comparable to that achieved by similarly engineered heterotrophic organisms. Włodarczyk et al. discover that cyanobacterium Synechococcus sp. PCC 11901 accumulates three times more biomass than other cyanobacterial strains in the same conditions. An engineered version of this strain also produces as much free fatty acid as other commonly used heterotrophic microorganisms, suggesting its utility for the sustainable production of carbon-based molecules.
Collapse
|
11
|
Elucidating the unique physiological responses of halotolerant Scenedesmus sp. cultivated in sea water for biofuel production. ALGAL RES 2019. [DOI: 10.1016/j.algal.2018.12.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
|
12
|
Hills KA, Hyne RV, Kefford BJ. Species of freshwater invertebrates that are sensitive to one saline water are mostly sensitive to another saline water but an exception exists. Philos Trans R Soc Lond B Biol Sci 2018; 374:rstb.2018.0003. [PMID: 30509905 DOI: 10.1098/rstb.2018.0003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/23/2018] [Indexed: 01/18/2023] Open
Abstract
Coal mining and extraction of methane from coal beds generate effluent with elevated salinity or major ion concentrations. If discharged to freshwater systems, these effluents may have adverse environmental effects. There is a growing body of work on freshwater invertebrates that indicates variation in the proportion of major ions can be more important than salinity when determining toxicity. However, it is not known if saline toxicity in a subset of species is representative of toxicity across all freshwater invertebrates. If patterns derived from a subset of species are representative of all freshwater invertebrates, then we would expect a correlation in the relative sensitivity of these species to multiple saline waters. Here, we determine if there is a correlation between the acute (96 h) lethal toxicity in freshwater invertebrates to synthetic marine salts (SMS) and sodium bicarbonate (NaHCO3) added to dechlorinated Sydney tap water. NaHCO3 is a major component of many coal bed effluents. However, most salinization in Australia exhibits ionic composition similar to seawater, which has very little HCO3 - Across all eight species tested, NaHCO3 was 2-50 times more toxic than SMS. We also observed strong correlations in the acute toxicity of seven of the tested species to SMS and NaHCO3 The strongest relationship (LC50 r 2 = 0.906) was dependent on the exclusion of one species, Paratya australiensis (Decopoda: Atyidae), which was the most sensitive species tested to NaHCO3, but the second-most tolerant of SMS. We conclude that differences in the toxicity of different proportions of major ions can be similar across a wide range of species. Therefore, a small subset of the invertebrate community can be representative of the whole. However, there are some species, which based on the species tested in the current study appear to be a minority, that respond differently to saline effluent and need to be considered separately. We discuss the implications of this study for the management of saline coal bed waters.This article is part of the theme issue 'Salt in freshwaters: causes, ecological consequences and future prospects'.
Collapse
Affiliation(s)
- Kasey A Hills
- Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory 2601, Australia.,Science Division, Office of Environment and Heritage, PO Box 29, Lidcombe, New South Wales 1825, Australia
| | - Ross V Hyne
- Science Division, Office of Environment and Heritage, PO Box 29, Lidcombe, New South Wales 1825, Australia
| | - Ben J Kefford
- Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory 2601, Australia
| |
Collapse
|
13
|
Metabolic engineering tools in model cyanobacteria. Metab Eng 2018; 50:47-56. [DOI: 10.1016/j.ymben.2018.03.014] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 03/15/2018] [Accepted: 03/15/2018] [Indexed: 12/27/2022]
|
14
|
Nozzi NE, Case AE, Carroll AL, Atsumi S. Systematic Approaches to Efficiently Produce 2,3-Butanediol in a Marine Cyanobacterium. ACS Synth Biol 2017; 6:2136-2144. [PMID: 28718632 DOI: 10.1021/acssynbio.7b00157] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cyanobacteria have attracted significant interest as a platform for renewable production of fuel and feedstock chemicals from abundant atmospheric carbon dioxide by way of photosynthesis. While great strides have been made in developing this technology in freshwater cyanobacteria, logistical issues remain in scale-up. Use of the cyanobacterium Synechococcus sp. PCC 7002 (7002) as a chemical production chassis could address a number of these issues given the higher tolerance to salt, light, and heat as well as the fast growth rate of 7002 in comparison to traditional model cyanobacteria such as Synechococcus elongatus PCC 7942 and Synechocystis sp. PCC 6803. However, despite growing interest, the development of genetic engineering tools for 7002 continues to lag behind those available for model cyanobacterial strains. In this work we demonstrate the systematic development of a 7002 production strain for the feedstock chemical 2,3-butanediol (23BD). We expand the range of tools available for use in 7002 by identifying and utilizing new integration sites for homologous recombination, demonstrating the inducibility of theophylline riboswitches, and screening a set of isopropyl β-d-1-thiogalactopyranoside (IPTG) inducible promoters. We then demonstrate improvements of 23BD production with the systematic screening of different conditions including: operon arrangement and copy number, light strength, inducer concentration, cell density at the time of induction, and nutrient concentration. Final production tests yielded titers of 1.6 g/L 23BD after 16 days at a rate of 100 mg/L/day. This work represents great strides in the development of 7002 as an industrially relevant production host.
Collapse
Affiliation(s)
- Nicole E. Nozzi
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Anna E. Case
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Austin L. Carroll
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Shota Atsumi
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| |
Collapse
|
15
|
Ren M, Zhang G, Ye Z, Qiao Z, Xie M, Lin Y, Li T, Zhao J. Metagenomic analysis reveals potential interactions in an artificial coculture. AMB Express 2017; 7:193. [PMID: 29098480 PMCID: PMC5668215 DOI: 10.1186/s13568-017-0490-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 10/14/2017] [Indexed: 01/23/2023] Open
Abstract
Disentangling the interactions between cyanobacteria and associated bacterial community is important for understanding the mechanisms that mediate the formation of cyanobacterial blooms in freshwater ecosystems. Despite the fact that a metagenomic approach enables researchers to profile the structure of microbial communities associated with cyanobacteria, reconstructing genome sequences for all members remains inefficient, due to the inherent enormous microbial diversity. Here, we have established a stable coculture system under high salinity, originally from a mixture of an axenic cyanobacterium Synechococcus sp. PCC 7002 and a non-axenic bloom-forming cyanobacterium Microcystis colony. Metagenomic analysis showed that the coculture consists of S. sp. PCC 7002 and two heterotrophic bacteria, designated as Pseudomonas stutzeri TAIHU and Mesorhizobium sp. TAIHU, respectively. And near-complete genome sequences of both bacteria were reconstructed from the metagenomic dataset with an average completeness of 99.8%. Genome-wide pathway analysis revealed that M. sp. TAIHU carried all the genes involved in the de novo biosynthesis of cobalamin, which is required by S. sp. PCC 7002 for growth. To cope with the high salinity in the coculture, experimental evidence demonstrated that S. sp. PCC 7002 would synthesize the compatible solutes including sucrose and glucosylglycerol, which are supposed to be exploited by both heterotrophic bacteria as potential carbon and/or nitrogen sources. Furthermore, the genes encoding for the biosynthesis of the ectoine, another common osmolyte are found exclusively in P. stutzeri TAIHU, while the genes responsible for the catabolism of ectoine and its derives are present only in M. sp. TAIHU. These genomic evidence indicates beneficial interaction between three members in the coculture. Establishment of the coculture system with relative simplicity provides a useful model system for investigating the interspecies interactions, and genome sequences of both bacteria associated with Microcystis bloom described here will facilitate the researcher to elucidate the role of these heterotrophic bacteria in the formation and maintenance of cyanobacterial bloom in freshwater ecosystem.
Collapse
|
16
|
Chen Z, Zhang G, Yang M, Li T, Ge F, Zhao J. Lysine Acetylome Analysis Reveals Photosystem II Manganese-stabilizing Protein Acetylation is Involved in Negative Regulation of Oxygen Evolution in Model Cyanobacterium Synechococcus sp. PCC 7002. Mol Cell Proteomics 2017; 16:1297-1311. [PMID: 28550166 PMCID: PMC5500762 DOI: 10.1074/mcp.m117.067835] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 05/09/2017] [Indexed: 12/11/2022] Open
Abstract
Nε-Acetylation of lysine residues represents a frequently occurring post-translational modification widespread in bacteria that plays vital roles in regulating bacterial physiology and metabolism. However, the role of lysine acetylation in cyanobacteria remains unclear, presenting a hurdle to in-depth functional study of this post-translational modification. Here, we report the lysine acetylome of Synechococcus sp. PCC 7002 (hereafter Synechococcus) using peptide prefractionation, immunoaffinity enrichment, and coupling with high-precision liquid chromatography-tandem mass spectrometry analysis. Proteomic analysis of Synechococcus identified 1653 acetylation sites on 802 acetylproteins involved in a broad range of biological processes. Interestingly, the lysine acetylated proteins were enriched for proteins involved in photosynthesis, for example. Functional studies of the photosystem II manganese-stabilizing protein were performed by site-directed mutagenesis and mutants mimicking either constitutively acetylated (K99Q, K190Q, and K219Q) or nonacetylated states (K99R, K190R, and K219R) were constructed. Mutation of the K190 acetylation site resulted in a distinguishable phenotype. Compared with the K190R mutant, the K190Q mutant exhibited a decreased oxygen evolution rate and an enhanced cyclic electron transport rate in vivo Our findings provide new insight into the molecular mechanisms of lysine acetylation that involved in the negative regulation of oxygen evolution in Synechococcus and creates opportunities for in-depth elucidation of the physiological role of protein acetylation in photosynthesis in cyanobacteria.
Collapse
Affiliation(s)
- Zhuo Chen
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China
- §Key Lab of Plant Stress Research, College of Life Science, Shandong Normal University, Jinan 250014, Shandong, China
| | - Guiying Zhang
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China
- ¶University of Chinese Academy of Sciences, Beijing 100094, China
| | - Mingkun Yang
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China
| | - Tao Li
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China;
| | - Feng Ge
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China;
| | - Jindong Zhao
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China
| |
Collapse
|
17
|
Hendry JI, Prasannan C, Ma F, Möllers KB, Jaiswal D, Digmurti M, Allen DK, Frigaard NU, Dasgupta S, Wangikar PP. Rerouting of carbon flux in a glycogen mutant of cyanobacteria assessed via isotopically non-stationary 13 C metabolic flux analysis. Biotechnol Bioeng 2017; 114:2298-2308. [PMID: 28600876 DOI: 10.1002/bit.26350] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 06/09/2017] [Accepted: 06/09/2017] [Indexed: 01/14/2023]
Abstract
Cyanobacteria, which constitute a quantitatively dominant phylum, have attracted attention in biofuel applications due to favorable physiological characteristics, high photosynthetic efficiency and amenability to genetic manipulations. However, quantitative aspects of cyanobacterial metabolism have received limited attention. In the present study, we have performed isotopically non-stationary 13 C metabolic flux analysis (INST-13 C-MFA) to analyze rerouting of carbon in a glycogen synthase deficient mutant strain (glgA-I glgA-II) of the model cyanobacterium Synechococcus sp. PCC 7002. During balanced photoautotrophic growth, 10-20% of the fixed carbon is stored in the form of glycogen via a pathway that is conserved across the cyanobacterial phylum. Our results show that deletion of glycogen synthase gene orchestrates cascading effects on carbon distribution in various parts of the metabolic network. Carbon that was originally destined to be incorporated into glycogen gets partially diverted toward alternate storage molecules such as glucosylglycerol and sucrose. The rest is partitioned within the metabolic network, primarily via glycolysis and tricarboxylic acid cycle. A lowered flux toward carbohydrate synthesis and an altered distribution at the glucose-1-phosphate node indicate flexibility in the network. Further, reversibility of glycogen biosynthesis reactions points toward the presence of futile cycles. Similar redistribution of carbon was also predicted by Flux Balance Analysis. The results are significant to metabolic engineering efforts with cyanobacteria where fixed carbon needs to be re-routed to products of interest. Biotechnol. Bioeng. 2017;114: 2298-2308. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- John I Hendry
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Charulata Prasannan
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.,DBT-Pan IIT Center for Bioenergy, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.,Wadhwani Research Center for Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Fangfang Ma
- Donald Danforth Plant Science Center, US Department of Agriculture, St. Louis, Missouri, 63132
| | - K Benedikt Möllers
- Department of Biology, University of Copenhagen, Helsingør, 3000, Denmark
| | - Damini Jaiswal
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Madhuri Digmurti
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Doug K Allen
- Donald Danforth Plant Science Center, US Department of Agriculture, St. Louis, Missouri, 63132.,Agricultural Research Service, US Department of Agriculture, St. Louis, Missouri, 63132
| | | | - Santanu Dasgupta
- Reliance Research and Development Centre, Reliance Corporate Park, Reliance Industries Ltd., Thane-Belapur Road, Ghansoli, Navi Mumbai, 400 701, India
| | - Pramod P Wangikar
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.,DBT-Pan IIT Center for Bioenergy, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.,Wadhwani Research Center for Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| |
Collapse
|
18
|
Vogel AIM, Lale R, Hohmann-Marriott MF. Streamlining recombination-mediated genetic engineering by validating three neutral integration sites in Synechococcus sp. PCC 7002. J Biol Eng 2017; 11:19. [PMID: 28592992 PMCID: PMC5458483 DOI: 10.1186/s13036-017-0061-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 05/08/2017] [Indexed: 11/17/2022] Open
Abstract
Background Synechococcus sp. PCC 7002 (henceforth Synechococcus) is developing into a powerful synthetic biology chassis. In order to streamline the integration of genes into the Synechococcus chromosome, validation of neutral integration sites with optimization of the DNA transformation protocol parameters is necessary. Availability of BioBrick-compatible integration modules is desirable to further simplifying chromosomal integrations. Results We designed three BioBrick-compatible genetic modules, each targeting a separate neutral integration site, A2842, A0935, and A0159, with varying length of homologous region, spanning from 100 to 800 nt. The performance of the different modules for achieving DNA integration were tested. Our results demonstrate that 100 nt homologous regions are sufficient for inserting a 1 kb DNA fragment into the Synechococcus chromosome. By adapting a transformation protocol from a related cyanobacterium, we shortened the transformation procedure for Synechococcus significantly. Conclusions The optimized transformation protocol reported in this study provides an efficient way to perform genetic engineering in Synechococcus. We demonstrated that homologous regions of 100 nt are sufficient for inserting a 1 kb DNA fragment into the three tested neutral integration sites. Integration at A2842, A0935 and A0159 results in only a minimal fitness cost for the chassis. This study contributes to developing Synechococcus as the prominent chassis for future synthetic biology applications. Electronic supplementary material The online version of this article (doi:10.1186/s13036-017-0061-8) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Anne Ilse Maria Vogel
- Department of Biotechnology, PhotoSynLab, NTNU, Norwegian University of Science and Technology, Trondheim, Norway
| | - Rahmi Lale
- Department of Biotechnology, PhotoSynLab, NTNU, Norwegian University of Science and Technology, Trondheim, Norway
| | | |
Collapse
|
19
|
Motwalli O, Essack M, Jankovic BR, Ji B, Liu X, Ansari HR, Hoehndorf R, Gao X, Arold ST, Mineta K, Archer JAC, Gojobori T, Mijakovic I, Bajic VB. In silico screening for candidate chassis strains of free fatty acid-producing cyanobacteria. BMC Genomics 2017; 18:33. [PMID: 28056772 PMCID: PMC5217662 DOI: 10.1186/s12864-016-3389-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 12/07/2016] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Finding a source from which high-energy-density biofuels can be derived at an industrial scale has become an urgent challenge for renewable energy production. Some microorganisms can produce free fatty acids (FFA) as precursors towards such high-energy-density biofuels. In particular, photosynthetic cyanobacteria are capable of directly converting carbon dioxide into FFA. However, current engineered strains need several rounds of engineering to reach the level of production of FFA to be commercially viable; thus new chassis strains that require less engineering are needed. Although more than 120 cyanobacterial genomes are sequenced, the natural potential of these strains for FFA production and excretion has not been systematically estimated. RESULTS Here we present the FFA SC (FFASC), an in silico screening method that evaluates the potential for FFA production and excretion of cyanobacterial strains based on their proteomes. A literature search allowed for the compilation of 64 proteins, most of which influence FFA production and a few of which affect FFA excretion. The proteins are classified into 49 orthologous groups (OGs) that helped create rules used in the scoring/ranking of algorithms developed to estimate the potential for FFA production and excretion of an organism. Among 125 cyanobacterial strains, FFASC identified 20 candidate chassis strains that rank in their FFA producing and excreting potential above the specifically engineered reference strain, Synechococcus sp. PCC 7002. We further show that the top ranked cyanobacterial strains are unicellular and primarily include Prochlorococcus (order Prochlorales) and marine Synechococcus (order Chroococcales) that cluster phylogenetically. Moreover, two principal categories of enzymes were shown to influence FFA production the most: those ensuring precursor availability for the biosynthesis of lipids, and those involved in handling the oxidative stress associated to FFA synthesis. CONCLUSION To our knowledge FFASC is the first in silico method to screen cyanobacteria proteomes for their potential to produce and excrete FFA, as well as the first attempt to parameterize the criteria derived from genetic characteristics that are favorable/non-favorable for this purpose. Thus, FFASC helps focus experimental evaluation only on the most promising cyanobacteria.
Collapse
Affiliation(s)
- Olaa Motwalli
- Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900 Kingdom of Saudi Arabia
| | - Magbubah Essack
- Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900 Kingdom of Saudi Arabia
| | - Boris R. Jankovic
- Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900 Kingdom of Saudi Arabia
| | - Boyang Ji
- Division of Systems & Synthetic Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 41296 Gothenburg, Sweden
| | - Xinyao Liu
- SABIC Corporate Research and Development (CRD), Thuwal, 23955-6900 Kingdom of Saudi Arabia
| | - Hifzur Rahman Ansari
- Pathogen Genomics Laboratory, Biological and Environmental Sciences and Engineering (BESE) Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900 Kingdom of Saudi Arabia
| | - Robert Hoehndorf
- Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900 Kingdom of Saudi Arabia
| | - Xin Gao
- Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900 Kingdom of Saudi Arabia
| | - Stefan T. Arold
- Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900 Kingdom of Saudi Arabia
| | - Katsuhiko Mineta
- Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900 Kingdom of Saudi Arabia
| | - John A. C. Archer
- Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900 Kingdom of Saudi Arabia
| | - Takashi Gojobori
- Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900 Kingdom of Saudi Arabia
| | - Ivan Mijakovic
- Division of Systems & Synthetic Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 41296 Gothenburg, Sweden
| | - Vladimir B. Bajic
- Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900 Kingdom of Saudi Arabia
| |
Collapse
|
20
|
Hounslow E, Kapoore RV, Vaidyanathan S, Gilmour DJ, Wright PC. The Search for a Lipid Trigger: The Effect of Salt Stress on the Lipid Profile of the Model Microalgal Species Chlamydomonas reinhardtii for Biofuels Production. ACTA ACUST UNITED AC 2016; 5:305-313. [PMID: 28409092 PMCID: PMC5361176 DOI: 10.2174/2211550105666160322234434] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 03/18/2016] [Accepted: 03/21/2016] [Indexed: 11/22/2022]
Abstract
BACKGROUND Algal cells produce neutral lipid when stressed and this can be used to generate biodiesel. OBJECTIVE Salt stressed cells of the model microalgal species Chlamydomonas reinhardtii were tested for their suitability to produce lipid for biodiesel. METHODS The starchless mutant of C. reinhardtii (CC-4325) was subjected to salt stress (0.1, 0.2 and 0.3 M NaCl) and transesterification and GC analysis were used to determine fatty acid methyl ester (FAME) content and profile. RESULTS Fatty acid profile was found to vary under salt stress conditions, with a clear distinction between 0.1 M NaCl, which the algae could tolerate, and the higher levels of NaCl (0.2 and 0.3 M), which caused cell death. Lipid content was increased under salt conditions, either through long-term exposure to 0.1 M NaCl, or short-term exposure to 0.2 and 0.3 M NaCl. Palmitic acid (C16:0) and linolenic acid (C18:3n3) were found to increase significantly at the higher salinities. CONCLUSION Salt increase can act as a lipid trigger for C. reinhardtii.
Collapse
Affiliation(s)
- Emily Hounslow
- ChELSI Institute, Department of Chemical and Biological Engineering, Faculty of Engineering, The University of Sheffield, Sheffield, UK.,Department of Molecular Biology and Biotechnology, Faculty of Science, The University of Sheffield, Sheffield, UK
| | - Rahul Vijay Kapoore
- ChELSI Institute, Department of Chemical and Biological Engineering, Faculty of Engineering, The University of Sheffield, Sheffield, UK
| | - Seetharaman Vaidyanathan
- ChELSI Institute, Department of Chemical and Biological Engineering, Faculty of Engineering, The University of Sheffield, Sheffield, UK
| | - D James Gilmour
- Department of Molecular Biology and Biotechnology, Faculty of Science, The University of Sheffield, Sheffield, UK
| | - Phillip C Wright
- ChELSI Institute, Department of Chemical and Biological Engineering, Faculty of Engineering, The University of Sheffield, Sheffield, UK
| |
Collapse
|
21
|
Tuning fresh: radiation through rewiring of central metabolism in streamlined bacteria. ISME JOURNAL 2016; 10:1902-14. [PMID: 26784354 PMCID: PMC5029164 DOI: 10.1038/ismej.2015.260] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 11/24/2015] [Accepted: 12/10/2015] [Indexed: 11/08/2022]
Abstract
Most free-living planktonic cells are streamlined and in spite of their limitations in functional flexibility, their vast populations have radiated into a wide range of aquatic habitats. Here we compared the metabolic potential of subgroups in the Alphaproteobacteria lineage SAR11 adapted to marine and freshwater habitats. Our results suggest that the successful leap from marine to freshwaters in SAR11 was accompanied by a loss of several carbon degradation pathways and a rewiring of the central metabolism. Examples for these are C1 and methylated compounds degradation pathways, the Entner–Doudouroff pathway, the glyoxylate shunt and anapleuretic carbon fixation being absent from the freshwater genomes. Evolutionary reconstructions further suggest that the metabolic modules making up these important freshwater metabolic traits were already present in the gene pool of ancestral marine SAR11 populations. The loss of the glyoxylate shunt had already occurred in the common ancestor of the freshwater subgroup and its closest marine relatives, suggesting that the adaptation to freshwater was a gradual process. Furthermore, our results indicate rapid evolution of TRAP transporters in the freshwater clade involved in the uptake of low molecular weight carboxylic acids. We propose that such gradual tuning of metabolic pathways and transporters toward locally available organic substrates is linked to the formation of subgroups within the SAR11 clade and that this process was critical for the freshwater clade to find and fix an adaptive phenotype.
Collapse
|
22
|
Ludwig M, Chua TT, Chew CY, Bryant DA. Fur-type transcriptional repressors and metal homeostasis in the cyanobacterium Synechococcus sp. PCC 7002. Front Microbiol 2015; 6:1217. [PMID: 26582412 PMCID: PMC4628125 DOI: 10.3389/fmicb.2015.01217] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Accepted: 10/19/2015] [Indexed: 11/29/2022] Open
Abstract
Metal homeostasis is a crucial cellular function for nearly all organisms. Some heavy metals (e.g., Fe, Zn, Co, Mo) are essential because they serve as cofactors for enzymes or metalloproteins, and chlorophototrophs such as cyanobacteria have an especially high demand for iron. At excessive levels, however, metals become toxic to cyanobacteria. Therefore, a tight control mechanism is essential for metal homeostasis. Metal homeostasis in microorganisms comprises two elements: metal acquisition from the environment and detoxification or excretion of excess metal ions. Different families of metal-sensing regulators exist in cyanobacteria and each addresses a more or less specific set of target genes. In this study the regulons of three Fur-type and two ArsR-SmtB-type regulators were investigated in a comparative approach in the cyanobacterium Synechococcus sp. PCC 7002. One Fur-type regulator controls genes for iron acquisition (Fur); one controls genes for zinc acquisition (Zur); and the third controls two genes involved in oxidative stress (Per). Compared to other well-investigated cyanobacterial strains, however, the set of target genes for each regulator is relatively small. Target genes for the two ArsR-SmtB transcriptional repressors (SmtB (SYNPCC7002_A2564) and SYNPCC7002_A0590) are involved in zinc homeostasis in addition to Zur. Their target genes, however, are less specific for zinc and point to roles in a broader heavy metal detoxification response.
Collapse
Affiliation(s)
- Marcus Ludwig
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park PA, USA
| | - Tiing Tiing Chua
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park PA, USA
| | - Chyue Yie Chew
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park PA, USA
| | - Donald A Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park PA, USA ; Department of Chemistry and Biochemistry, Montana State University, Bozeman MT, USA
| |
Collapse
|
23
|
Stam WT, Holleman HC. THE INFLUENCE OF DIFFERENT SALINITIES ON GROWTH AND MORPHOLOGICAL VARIABILITY OF A NUMBER OF PHORMIDIUM STRAINS (CYANOPHYCEAE) IN CULTURE. ACTA ACUST UNITED AC 2015. [DOI: 10.1111/j.1438-8677.1975.tb01028.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- W. T. Stam
- Biologisch Centrum, afd. Plantensystematiek, Rijksuniversiteit; Groningen
| | - H. C. Holleman
- Biologisch Centrum, afd. Plantensystematiek, Rijksuniversiteit; Groningen
| |
Collapse
|
24
|
Stam WT, Holleman HC. CULTURES OF PHORMIDIUM, PLECTONEMA, LYNGBYA AND SYNECHOCOCCUS (CYANOPHYCEAE) UNDER DIFFERENT CONDITIONS: THEIR GROWTH AND MORPHOLOGICAL VARIABILITY. ACTA ACUST UNITED AC 2015. [DOI: 10.1111/j.1438-8677.1979.tb01155.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- W. T. Stam
- Biologisch Centrum, Vakgroep Plantensystematiek; Rijksuniversiteit Groningen
| | - H. C. Holleman
- Biologisch Centrum, Vakgroep Plantensystematiek; Rijksuniversiteit Groningen
| |
Collapse
|
25
|
Xiong Q, Feng J, Li ST, Zhang GY, Qiao ZX, Chen Z, Wu Y, Lin Y, Li T, Ge F, Zhao JD. Integrated transcriptomic and proteomic analysis of the global response of Synechococcus to high light stress. Mol Cell Proteomics 2015; 14:1038-53. [PMID: 25681118 DOI: 10.1074/mcp.m114.046003] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Indexed: 12/14/2022] Open
Abstract
Sufficient light is essential for the growth and physiological functions of photosynthetic organisms, but prolonged exposure to high light (HL) stress can cause cellular damage and ultimately result in the death of these organisms. Synechococcus sp. PCC 7002 (hereafter Synechococcus 7002) is a unicellular cyanobacterium with exceptional tolerance to HL intensities. However, the molecular mechanisms involved in HL response by Synechococcus 7002 are not well understood. Here, an integrated RNA sequencing transcriptomic and quantitative proteomic analysis was performed to investigate the cellular response to HL in Synechococcus 7002. A total of 526 transcripts and 233 proteins were identified to be differentially regulated under HL stress. Data analysis revealed major changes in mRNAs and proteins involved in the photosynthesis pathways, resistance to light-induced damage, DNA replication and repair, and energy metabolism. A set of differentially expressed mRNAs and proteins were validated by quantitative RT-PCR and Western blot, respectively. Twelve genes differentially regulated under HL stress were selected for knockout generation and growth analysis of these mutants led to the identification of key genes involved in the response of HL in Synechococcus 7002. Taken altogether, this study established a model for global response mechanisms to HL in Synechococcus 7002 and may be valuable for further studies addressing HL resistance in photosynthetic organisms.
Collapse
Affiliation(s)
- Qian Xiong
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Jie Feng
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; §University of Chinese Academy of Sciences, Beijing 100039, China
| | - Si-ting Li
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; §University of Chinese Academy of Sciences, Beijing 100039, China
| | - Gui-ying Zhang
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; §University of Chinese Academy of Sciences, Beijing 100039, China
| | - Zhi-xian Qiao
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Zhuo Chen
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Ying Wu
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; §University of Chinese Academy of Sciences, Beijing 100039, China
| | - Yan Lin
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Tao Li
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China;
| | - Feng Ge
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China;
| | - Jin-dong Zhao
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China;
| |
Collapse
|
26
|
Yang Y, Feng J, Li T, Ge F, Zhao J. CyanOmics: an integrated database of omics for the model cyanobacterium Synechococcus sp. PCC 7002. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2015; 2015:bau127. [PMID: 25632108 PMCID: PMC4309022 DOI: 10.1093/database/bau127] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Cyanobacteria are an important group of organisms that carry out oxygenic photosynthesis and play vital roles in both the carbon and nitrogen cycles of the Earth. The annotated genome of Synechococcus sp. PCC 7002, as an ideal model cyanobacterium, is available. A series of transcriptomic and proteomic studies of Synechococcus sp. PCC 7002 cells grown under different conditions have been reported. However, no database of such integrated omics studies has been constructed. Here we present CyanOmics, a database based on the results of Synechococcus sp. PCC 7002 omics studies. CyanOmics comprises one genomic dataset, 29 transcriptomic datasets and one proteomic dataset and should prove useful for systematic and comprehensive analysis of all those data. Powerful browsing and searching tools are integrated to help users directly access information of interest with enhanced visualization of the analytical results. Furthermore, Blast is included for sequence-based similarity searching and Cluster 3.0, as well as the R hclust function is provided for cluster analyses, to increase CyanOmics’s usefulness. To the best of our knowledge, it is the first integrated omics analysis database for cyanobacteria. This database should further understanding of the transcriptional patterns, and proteomic profiling of Synechococcus sp. PCC 7002 and other cyanobacteria. Additionally, the entire database framework is applicable to any sequenced prokaryotic genome and could be applied to other integrated omics analysis projects. Database URL: http://lag.ihb.ac.cn/cyanomics
Collapse
Affiliation(s)
- Yaohua Yang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China, University of Chinese Academy of Sciences, Beijing 100049, China, College of Life Science, Peking University, Beijing 100871, China Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China, University of Chinese Academy of Sciences, Beijing 100049, China, College of Life Science, Peking University, Beijing 100871, China
| | - Jie Feng
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China, University of Chinese Academy of Sciences, Beijing 100049, China, College of Life Science, Peking University, Beijing 100871, China Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China, University of Chinese Academy of Sciences, Beijing 100049, China, College of Life Science, Peking University, Beijing 100871, China Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China, University of Chinese Academy of Sciences, Beijing 100049, China, College of Life Science, Peking University, Beijing 100871, China
| | - Tao Li
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China, University of Chinese Academy of Sciences, Beijing 100049, China, College of Life Science, Peking University, Beijing 100871, China
| | - Feng Ge
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China, University of Chinese Academy of Sciences, Beijing 100049, China, College of Life Science, Peking University, Beijing 100871, China
| | - Jindong Zhao
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China, University of Chinese Academy of Sciences, Beijing 100049, China, College of Life Science, Peking University, Beijing 100871, China Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China, University of Chinese Academy of Sciences, Beijing 100049, China, College of Life Science, Peking University, Beijing 100871, China
| |
Collapse
|
27
|
Bernstein HC, Konopka A, Melnicki MR, Hill EA, Kucek LA, Zhang S, Shen G, Bryant DA, Beliaev AS. Effect of mono- and dichromatic light quality on growth rates and photosynthetic performance of Synechococcus sp. PCC 7002. Front Microbiol 2014; 5:488. [PMID: 25285095 PMCID: PMC4168726 DOI: 10.3389/fmicb.2014.00488] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 08/30/2014] [Indexed: 01/30/2023] Open
Abstract
Synechococcus sp. PCC 7002 was grown to steady state in optically thin turbidostat cultures under conditions for which light quantity and quality was systematically varied by modulating the output of narrow-band LEDs. Cells were provided photons absorbed primarily by chlorophyll (680 nm) or phycocyanin (630 nm) as the organism was subjected to four distinct mono- and dichromatic regimes. During cultivation with dichromatic light, growth rates were generally proportional to the total incident irradiance at values <275 μmol photons m(-2) · s(-1) and were not affected by the ratio of 630:680 nm wavelengths. Notably, under monochromatic light conditions, cultures exhibited similar growth rates only when they were irradiated with 630 nm light; cultures irradiated with only 680 nm light grew at rates that were 60-70% of those under other light quality regimes at equivalent irradiances. The functionality of photosystem II and associated processes such as maximum rate of photosynthetic electron transport, rate of cyclic electron flow, and rate of dark respiration generally increased as a function of growth rate. Nonetheless, some of the photophysiological parameters measured here displayed distinct patterns with respect to growth rate of cultures adapted to a single wavelength including phycobiliprotein content, which increased under severely light-limited growth conditions. Additionally, the ratio of photosystem II to photosystem I increased ~40% over the range of growth rates, although cells grown with 680 nm light only had the highest ratios. These results suggest the presence of effective mechanisms which allow acclimation of Synechococcus sp. PCC 7002 acclimation to different irradiance conditions.
Collapse
Affiliation(s)
- Hans C. Bernstein
- Biological Sciences Division, Pacific Northwest National LaboratoryRichland, WA, USA
- Chemical and Biological Signature Science, Pacific Northwest National LaboratoryRichland, WA, USA
| | - Allan Konopka
- Biological Sciences Division, Pacific Northwest National LaboratoryRichland, WA, USA
- Department of Biological Sciences, Purdue UniversityW. Lafayette, IN, USA
| | - Matthew R. Melnicki
- Biological Sciences Division, Pacific Northwest National LaboratoryRichland, WA, USA
| | - Eric A. Hill
- Biological Sciences Division, Pacific Northwest National LaboratoryRichland, WA, USA
| | - Leo A. Kucek
- Biological Sciences Division, Pacific Northwest National LaboratoryRichland, WA, USA
| | - Shuyi Zhang
- Department of Biochemistry and Molecular Biology, The Pennsylvania State UniversityUniversity Park, PA, USA
| | - Gaozhong Shen
- Department of Biological Sciences, Purdue UniversityW. Lafayette, IN, USA
| | - Donald A. Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State UniversityUniversity Park, PA, USA
- Department of Chemistry and Biochemistry, Montana State UniversityBozeman, MT, USA
| | - Alexander S. Beliaev
- Biological Sciences Division, Pacific Northwest National LaboratoryRichland, WA, USA
| |
Collapse
|
28
|
Bernal OI, Mooney CB, Flickinger MC. Specific photosynthetic rate enhancement by cyanobacteria coated onto paper enables engineering of highly reactive cellular biocomposite “leaves”. Biotechnol Bioeng 2014; 111:1993-2008. [DOI: 10.1002/bit.25280] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 04/22/2014] [Accepted: 04/28/2014] [Indexed: 01/01/2023]
Affiliation(s)
- Oscar I. Bernal
- Department of Chemical and Biomolecular Engineering; North Carolina State University; 911 Partners Way Raleigh North Carolina 27695
| | - Charles B. Mooney
- Analytical Instrumentation Facility; North Carolina State University; Raleigh North Carolina
| | - Michael C. Flickinger
- Department of Chemical and Biomolecular Engineering; North Carolina State University; 911 Partners Way Raleigh North Carolina 27695
- Golden-LEAF Biomanufacturing Training and Education Center; North Carolina State University; Raleigh North Carolina
| |
Collapse
|
29
|
Ruffing AM. Improved Free Fatty Acid Production in Cyanobacteria with Synechococcus sp. PCC 7002 as Host. Front Bioeng Biotechnol 2014; 2:17. [PMID: 25152890 PMCID: PMC4126656 DOI: 10.3389/fbioe.2014.00017] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 05/11/2014] [Indexed: 12/17/2022] Open
Abstract
Microbial free fatty acids (FFAs) have been proposed as a potential feedstock for renewable energy. The ability to directly convert carbon dioxide into FFAs makes cyanobacteria ideal hosts for renewable FFA production. Previous metabolic engineering efforts using the cyanobacterial hosts Synechocystis sp. PCC 6803 and Synechococcus elongatus PCC 7942 have demonstrated this direct conversion of carbon dioxide into FFAs; however, FFA yields in these hosts are limited by the negative impact of FFA production on the host cell physiology. This work investigates the use of Synechococcus sp. PCC 7002 as a cyanobacterial host for FFA production. In comparison to S. elongatus PCC 7942, Synechococcus sp. PCC 7002 strains produced and excreted FFAs at similar concentrations but without the detrimental effects on host physiology. The enhanced tolerance to FFA production with Synechococcus sp. PCC 7002 was found to be temperature-dependent, with physiological effects such as reduced photosynthetic yield and decreased photosynthetic pigments observed at higher temperatures. Additional genetic manipulations were targeted for increased FFA production, including thioesterases and ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO). Overexpression of non-native RuBisCO subunits (rbcLS) from a psbAI promoter resulted in more than a threefold increase in FFA production, with excreted FFA concentrations reaching >130 mg/L. This work illustrates the importance of host strain selection for cyanobacterial biofuel production and demonstrates that the FFA tolerance of Synechococcus sp. PCC 7002 can allow for high yields of excreted FFA.
Collapse
Affiliation(s)
- Anne M Ruffing
- Department of Bioenergy and Defense Technologies, Sandia National Laboratories , Albuquerque, NM , USA
| |
Collapse
|
30
|
Beliaev AS, Romine MF, Serres M, Bernstein HC, Linggi BE, Markillie LM, Isern NG, Chrisler WB, Kucek LA, Hill EA, Pinchuk GE, Bryant DA, Wiley HS, Fredrickson JK, Konopka A. Inference of interactions in cyanobacterial-heterotrophic co-cultures via transcriptome sequencing. ISME JOURNAL 2014; 8:2243-55. [PMID: 24781900 DOI: 10.1038/ismej.2014.69] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 03/20/2014] [Accepted: 03/24/2014] [Indexed: 11/10/2022]
Abstract
We used deep sequencing technology to identify transcriptional adaptation of the euryhaline unicellular cyanobacterium Synechococcus sp. PCC 7002 and the marine facultative aerobe Shewanella putrefaciens W3-18-1 to growth in a co-culture and infer the effect of carbon flux distributions on photoautotroph-heterotroph interactions. The overall transcriptome response of both organisms to co-cultivation was shaped by their respective physiologies and growth constraints. Carbon limitation resulted in the expansion of metabolic capacities, which was manifested through the transcriptional upregulation of transport and catabolic pathways. Although growth coupling occurred via lactate oxidation or secretion of photosynthetically fixed carbon, there was evidence of specific metabolic interactions between the two organisms. These hypothesized interactions were inferred from the excretion of specific amino acids (for example, alanine and methionine) by the cyanobacterium, which correlated with the downregulation of the corresponding biosynthetic machinery in Shewanella W3-18-1. In addition, the broad and consistent decrease of mRNA levels for many Fe-regulated Synechococcus 7002 genes during co-cultivation may indicate increased Fe availability as well as more facile and energy-efficient mechanisms for Fe acquisition by the cyanobacterium. Furthermore, evidence pointed at potentially novel interactions between oxygenic photoautotrophs and heterotrophs related to the oxidative stress response as transcriptional patterns suggested that Synechococcus 7002 rather than Shewanella W3-18-1 provided scavenging functions for reactive oxygen species under co-culture conditions. This study provides an initial insight into the complexity of photoautotrophic-heterotrophic interactions and brings new perspectives of their role in the robustness and stability of the association.
Collapse
Affiliation(s)
- Alexander S Beliaev
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Margie F Romine
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Margrethe Serres
- Josephine Bay Paul Center, Marine Biological Laboratory, Woods Hole, MA, USA
| | - Hans C Bernstein
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Bryan E Linggi
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Lye M Markillie
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Nancy G Isern
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, USA
| | - William B Chrisler
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Leo A Kucek
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Eric A Hill
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Grigoriy E Pinchuk
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Donald A Bryant
- 1] Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA [2] Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, USA
| | - H Steven Wiley
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Jim K Fredrickson
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Allan Konopka
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| |
Collapse
|
31
|
Vu TT, Hill EA, Kucek LA, Konopka AE, Beliaev AS, Reed JL. Computational evaluation of Synechococcus sp. PCC 7002 metabolism for chemical production. Biotechnol J 2013; 8:619-30. [PMID: 23613453 DOI: 10.1002/biot.201200315] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 03/25/2013] [Accepted: 04/11/2013] [Indexed: 11/06/2022]
Abstract
Cyanobacteria are ideal metabolic engineering platforms for carbon-neutral biotechnology because they directly convert CO2 to a range of valuable products. In this study, we present a computational assessment of biochemical production in Synechococcus sp. PCC 7002 (Synechococcus 7002), a fast growing cyanobacterium whose genome has been sequenced, and for which genetic modification methods have been developed. We evaluated the maximum theoretical yields (mol product per mol CO2 or mol photon) of producing various chemicals under photoautotrophic and dark conditions using a genome-scale metabolic model of Synechococcus 7002. We found that the yields were lower under dark conditions, compared to photoautotrophic conditions, due to the limited amount of energy and reductant generated from glycogen. We also examined the effects of photon and CO2 limitations on chemical production under photoautotrophic conditions. In addition, using various computational methods such as minimization of metabolic adjustment (MOMA), relative metabolic change (RELATCH), and OptORF, we identified gene-knockout mutants that are predicted to improve chemical production under photoautotrophic and/or dark anoxic conditions. These computational results are useful for metabolic engineering of cyanobacteria to synthesize value-added products.
Collapse
Affiliation(s)
- Trang T Vu
- Department of Chemical and Biological Engineering, University of Wisconsin, Madison, Madison, WI, USA
| | | | | | | | | | | |
Collapse
|
32
|
Ludwig M, Bryant DA. Synechococcus sp. Strain PCC 7002 Transcriptome: Acclimation to Temperature, Salinity, Oxidative Stress, and Mixotrophic Growth Conditions. Front Microbiol 2012; 3:354. [PMID: 23087677 PMCID: PMC3468840 DOI: 10.3389/fmicb.2012.00354] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 09/15/2012] [Indexed: 12/29/2022] Open
Abstract
Synechococcus sp. strain PCC 7002 is a unicellular, euryhaline cyanobacterium. It is a model organism for studies of cyanobacterial metabolism and has great potential for biotechnological applications. It exhibits an exceptional tolerance of high-light irradiation and shows very rapid growth. The habitats from which this and closely related strains were isolated are subject to changes in several environmental factors, including light, nutrient supply, temperature, and salinity. In this study global transcriptome profiling via RNAseq has been used to perform a comparative and integrated study of global changes in cells grown at different temperatures, at different salinities, and under mixotrophic conditions, when a metabolizable organic carbon source was present. Furthermore, the transcriptomes were investigated for cells that were subjected to a heat shock and that were exposed to oxidative stress. Lower growth temperatures caused relatively minor changes of the transcriptome; the most prominent changes affected fatty acid desaturases. A heat shock caused severe changes of the transcriptome pattern; transcripts for genes associated with major metabolic pathways declined and those for different chaperones increased dramatically. Oxidative stress, however, left the transcript pattern almost unaffected. When grown at high salinity, Synechococcus sp. PCC 7002 had increased expression of genes involved in compatible solute biosynthesis and showed increased mRNA levels for several genes involved in electron transport. Transcripts of two adjacent genes dramatically increased upon growth at high salinity; the respective proteins are putatively involved in coping with oxidative stress and in triggering ion channels. Only minor changes were observed when cells were grown at low salinity or when the growth medium was supplemented with glycerol. However, the transcriptome data suggest that cells must acclimate to excess reducing equivalents when a reduced C-source is present.
Collapse
Affiliation(s)
- Marcus Ludwig
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University University Park, PA, USA
| | | |
Collapse
|
33
|
Ludwig M, Bryant DA. Acclimation of the Global Transcriptome of the Cyanobacterium Synechococcus sp. Strain PCC 7002 to Nutrient Limitations and Different Nitrogen Sources. Front Microbiol 2012; 3:145. [PMID: 22514553 PMCID: PMC3323872 DOI: 10.3389/fmicb.2012.00145] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 03/26/2012] [Indexed: 11/29/2022] Open
Abstract
The unicellular, euryhaline cyanobacterium Synechococcus sp. strain PCC 7002 is a model organism for laboratory-based studies of cyanobacterial metabolism and is a potential platform for biotechnological applications. Two of its most notable properties are its exceptional tolerance of high-light intensity and very rapid growth under optimal conditions. In this study, transcription profiling by RNAseq has been used to perform an integrated study of global changes in transcript levels in cells subjected to limitation for the major nutrients CO2, nitrogen, sulfate, phosphate, and iron. Transcriptional patterns for cells grown on nitrate, ammonia, and urea were also studied. Nutrient limitation caused strong decreases of transcript levels of the genes encoding major metabolic pathways, especially for components of the photosynthetic apparatus, CO2 fixation, and protein biosynthesis. Uptake mechanisms for the respective nutrients were strongly up-regulated. The transcription data further suggest that major changes in the composition of the NADH dehydrogenase complex occur upon nutrient limitation. Transcripts for flavoproteins increased strongly when CO2 was limiting. Genes involved in protection from oxidative stress generally showed high, constitutive transcript levels, which possibly explains the high-light tolerance of this organism. The transcriptomes of cells grown with ammonia or urea as nitrogen source showed increased transcript levels for components of the CO2 fixation machinery compared to cells grown with nitrate, but in general transcription differences in cells grown on different N-sources exhibited surprisingly minor differences.
Collapse
Affiliation(s)
- Marcus Ludwig
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University University Park, PA, USA
| | | |
Collapse
|
34
|
Ludwig M, Bryant DA. Transcription Profiling of the Model Cyanobacterium Synechococcus sp. Strain PCC 7002 by Next-Gen (SOLiD™) Sequencing of cDNA. Front Microbiol 2011; 2:41. [PMID: 21779275 PMCID: PMC3133671 DOI: 10.3389/fmicb.2011.00041] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Accepted: 02/22/2011] [Indexed: 11/24/2022] Open
Abstract
The genome of the unicellular, euryhaline cyanobacterium Synechococcus sp. PCC 7002 encodes about 3200 proteins. Transcripts were detected for nearly all annotated open reading frames by a global transcriptomic analysis by Next-Generation (SOLiD™) sequencing of cDNA. In the cDNA samples sequenced, ∼90% of the mapped sequences were derived from the 16S and 23S ribosomal RNAs and ∼10% of the sequences were derived from mRNAs. In cells grown photoautotrophically under standard conditions [38°C, 1% (v/v) CO(2) in air, 250 μmol photons m(-2) s(-1)], the highest transcript levels (up to 2% of the total mRNA for the most abundantly transcribed genes; e.g., cpcAB, psbA, psaA) were generally derived from genes encoding structural components of the photosynthetic apparatus. High-light exposure for 1 h caused changes in transcript levels for genes encoding proteins of the photosynthetic apparatus, Type-1 NADH dehydrogenase complex and ATP synthase, whereas dark incubation for 1 h resulted in a global decrease in transcript levels for photosynthesis-related genes and an increase in transcript levels for genes involved in carbohydrate degradation. Transcript levels for pyruvate kinase and the pyruvate dehydrogenase complex decreased sharply in cells incubated in the dark. Under dark anoxic (fermentative) conditions, transcript changes indicated a global decrease in transcripts for respiratory proteins and suggested that cells employ an alternative phosphoenolpyruvate degradation pathway via phosphoenolpyruvate synthase (ppsA) and the pyruvate:ferredoxin oxidoreductase (nifJ). Finally, the data suggested that an apparent operon involved in tetrapyrrole biosynthesis and fatty acid desaturation, acsF2-ho2-hemN2-desF, may be regulated by oxygen concentration.
Collapse
Affiliation(s)
- Marcus Ludwig
- Department of Biochemistry and Molecular Biology, The Pennsylvania State UniversityUniversity Park, PA, USA
| | - Donald A. Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State UniversityUniversity Park, PA, USA
| |
Collapse
|
35
|
A glycine betaine transport system in Aphanothece halophytica and other glycine betaine-synthesising cyanobacteria. Arch Microbiol 1987. [DOI: 10.1007/bf00406140] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
36
|
Reed RH, Richardson DL, Stewart WD. Na+ uptake and extrusion in the cyanobacterium SynechocystisPCC6714 in response to hypersaline treatment. Evidence for transient changes in plasmalemma Na+ permeability. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 1985. [DOI: 10.1016/0005-2736(85)90455-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
37
|
Reed RH, Stewart WD. Evidence for turgor-sensitive K+ influx in the cyanobacteria Anabaena variabilis ATCC29413 and Synechocystis PCC6714. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 1985. [DOI: 10.1016/0005-2736(85)90533-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
38
|
Roussard-Jacquemin M. Sur quelques aspects du rôle essentiel du sodium chez Anacystis nidulans. ACTA ACUST UNITED AC 1982. [DOI: 10.1016/s0044-328x(82)80177-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2022]
|
39
|
Reed RH, Rowell P, Stewart WD. Characterization of the transport of potassium ions in the cyanobacterium Anabaena variabilis Kütz. EUROPEAN JOURNAL OF BIOCHEMISTRY 1981; 116:323-30. [PMID: 6788551 DOI: 10.1111/j.1432-1033.1981.tb05337.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Interrelationships between potassium-ion transport and transplasmalemma electrical-potential difference (delta psi m) have been investigated in Anabaena variabilis (ATCC 29413) by measuring K+ translocation and membrane potential in parallel. At pH 7.0, 5 mmol . dm-3 external K+, there was a thirtyfold accumulation of K+. The K+ equilibrium potential was lower (more negative) than the measured membrane potential by up to 20 mV, (delta psi K+ = -90 mV; delta psi m = -70 mV to -75 mV, respectively). Dark pretreatment and low temperature (4 degrees C) reduced internal K+ and depolarized delta psi m. External pH affected K+ translocation and membrane potential; delta psi m was hyperpolarized at high external pH; transplasmalemma K+ fluxes and internal K+ concentration were also increased at high pH. The effects of pH upon delta psi m, coupled with the finding that the membrane potential was relatively insensitive to external K+, suggest that delta psi m is unlikely to be due primarily to a diffusion potential of K+, but that the membrane potential is maintained by an electrogenic proton-extrusion mechanism. There was no close (obligate) link between K+ transport and changes in delta psi m. Carbonylcyanide m-chlorophenylhydrazone decreased K+ fluxes, internal K+ and delta psi m when added in amounts up to 100 mumol . dm-3. However, delta psi K+ was always more negative than delta psi m. Valinomycin up to concentrations of 50 mumol . dm-3 increased transplasmalemma K+ fluxes by up to 300%, while changes in delta psi m were negligible. Internal K+ was unaffected by valinomycin. N,N'-Dicyclohexylcarbodiimide at concentrations up to 100 mumol . dm-3, reduced K+ flux rates and caused a hyperpolarization of delta psi m. These observations suggest that delta psi m is primarily due to electron transport reactions at the plasmalemma and that K+ transport is energy-dependent. In the presence of dicyclohexylcarbodiimide, internal K+ redistributed in accordance with the membrane potential, suggesting that passive uniport in response to delta psi m (i.e. secondary active transport) is not usually important but may operate when primary active mechanisms are blocked.
Collapse
|
40
|
Potts M, Friedmann EI. Effects of water stress on cryptoendolithic cyanobacteria from hot desert rocks. Arch Microbiol 1981. [DOI: 10.1007/bf00425938] [Citation(s) in RCA: 78] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
41
|
|
42
|
Isolation and characterization of rapidly-growing, marine, nitrogen-fixing strains of blue-green algae. Arch Microbiol 1979. [DOI: 10.1007/bf00689980] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
43
|
Schiewer U, Erdmann N, Kuhnke KH. NaCl-Wirkung auf die Photosyntheseintensität von Blaualgen Die Wirkung unterschiedlicher NaCl-Konzentrationen auf die Photosyntheseintensität der Blaualgen Microcystis firma und Synechocystis aquatilis. ACTA ACUST UNITED AC 1978. [DOI: 10.1016/s0015-3796(17)30409-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
44
|
Isolation and characterization of a marine Anabaena sp. capable of rapid growth on molecular nitrogen. Arch Microbiol 1977. [DOI: 10.1007/bf00446862] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
45
|
Schenk HEA. Zur osmotischen Beeinflussung der Photosynthese von Cyanophora paradoxa Korsch. durch Saccharose. Arch Microbiol 1977. [DOI: 10.1007/bf00446871] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
46
|
Miller DM, Jones JH, Yopp JH, Tindall DR, Schmid WE. Ion metabolism in a halophilic blue-green alga, Aphanothece halophytica. Arch Microbiol 1976; 111:145-9. [PMID: 828029 DOI: 10.1007/bf00446561] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The intracellular ion content of the halophilic blue-green alga, Aphanthece halophytica was studied as a function of age, external sodium and external potassium concentration. Intracellular Na+ was found to be about 0.38 millimoles/g dry mass. Intracellular K+ concentrations were as high as 1 M and varied directly with external salinity. Intracellular Ca++ and Mg++ were in the range previously reported for fresh water blue-green algae despite their extremely high extracellular concentrations. Average cell size is consistent at room temperature with two exceptions. When the outside K+ is lower than 6.5 mM the cells tend to be smaller with less intracellular K+ and high Ca++. In stationary phase cultrues the cells are larger with high intracellular Mg++ and low K+.
Collapse
|
47
|
Abstract
The isolation of a halophilic blue-green alga, Aphanothece halophytica, from Great Salt Lake is described. The organism was cultured from waters with salinities up to saturated NaC1 (about 30% w/v). It has an optimum salinity for growth of about 16% NaC1, but can grow very slowly even in saturated NaC1. Based on the study of the Great Salt Lake organism, and on a review of the earlier literature, it is concluded that despite recent reports to the contrary, true halophilic blue-green algae do exist.
Collapse
|
48
|
Bibliography. ACTA ACUST UNITED AC 1976. [DOI: 10.1016/s0070-4571(08)71171-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
49
|
Wirkung unterschiedlicher Konzentrationen von NaCl und anderen osmotisch wirksamen Substanzen auf die CO2-Fixierung der einzelligen Alge Platymonas subcordiformis. Oecologia 1975; 20:237-254. [DOI: 10.1007/bf00347476] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/1975] [Indexed: 10/26/2022]
|
50
|
Charlang G, Horowitz NH. Membrane permeability and the loss of germination factor from Neurospora crassa at low water activities. J Bacteriol 1974; 117:261-4. [PMID: 4358044 PMCID: PMC246552 DOI: 10.1128/jb.117.1.261-264.1974] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Neurospora crassa conidia incubating in buffer at low water activities (a(w)) release a germination-essential component as well as 260-nm absorbing and ninhydrin-positive materials, regardless of whether an electrolyte or non-electrolyte is used to reduce a(w). Chloroform and antibiotics known to increase cell-membrane permeability have a similar effect. This suggests that membrane damage occurs in media of low a(w) and that an increase in permeability is responsible for the release of cellular components. The damage caused in media of low a(w) is nonlethal in most cases, and the conidia recover when transferred to nutrient medium.
Collapse
|