1
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Lee SY, Lee JS, Sim SJ. Cost-effective production of bioplastic polyhydroxybutyrate via introducing heterogeneous constitutive promoter and elevating acetyl-Coenzyme A pool of rapidly growing cyanobacteria. BIORESOURCE TECHNOLOGY 2024; 394:130297. [PMID: 38185449 DOI: 10.1016/j.biortech.2023.130297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 12/31/2023] [Accepted: 12/31/2023] [Indexed: 01/09/2024]
Abstract
Bioplastic production using cyanobacteria can be an effective strategy to cope with environmental problems caused by using petroleum-based plastics. Synechococcus elongatus UTEX 2973 with heterogeneous phaCAB can produce bioplastic polyhydroxybutyrate (PHB) with a high CO2 uptake rate. For cost-effective production of PHB in S. elongatus UTEX 2973, phaCAB was expressed by the constitutive Pcpc560, resulting in the production of 226 mg/L of PHB by only photoautotrophic cultivation without the addition of inducer. Several culture conditions were applied to increase PHB productivity, and when acetate was supplied at a concentration of 1 g/L as an organic carbon source, productivity significantly increased resulting in 607.2 mg/L of PHB and additive cost reduction of more than 300 times was achieved compared to IPTG. Consequently, these results suggest the possibility of cyanobacteria as an agent that can economically produce PHB and as a solution to the problem of petroleum-based plastics.
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Affiliation(s)
- So Young Lee
- Department of Chemical and Biological Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Jeong Seop Lee
- Department of Chemical and Biological Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Sang Jun Sim
- Department of Chemical and Biological Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
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2
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Utharn S, Jantaro S. The adc1 knockout with proC overexpression in Synechocystis sp. PCC 6803 induces a diversion of acetyl-CoA to produce more polyhydroxybutyrate. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:6. [PMID: 38218963 PMCID: PMC10788017 DOI: 10.1186/s13068-024-02458-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 01/05/2024] [Indexed: 01/15/2024]
Abstract
BACKGROUND Lack of nutrients, in particular nitrogen and phosphorus, has been known in the field to sense glutamate production via 2-oxoglutarate and subsequently accelerate carbon storage, including glycogen and polyhydroxybutyrate (PHB), in cyanobacteria, but a few studies have focused on arginine catabolism. In this study, we first time demonstrated that gene manipulation on proC and adc1, related to proline and polyamine syntheses in arginine catabolism, had a significant impact on enhanced PHB production during late growth phase and nutrient-modified conditions. We constructed Synechocystis sp. PCC 6803 with an overexpressing proC gene, encoding Δ1pyrroline-5-carboxylate reductase in proline production, and adc1 disruption resulted in lower polyamine synthesis. RESULTS Three engineered Synechocystis sp. PCC 6803 strains, including a ProC-overexpressing strain (OXP), adc1 mutant, and an OXP strain lacking the adc1 gene (OXP/Δadc1), certainly increased the PHB accumulation under nitrogen and phosphorus deficiency. The possible advantages of single proC overexpression include improved PHB and glycogen storage in late phase of growth and long-term stress situations. However, on day 7 of treatment, the synergistic impact created by OXP/Δadc1 increased PHB synthesis by approximately 48.9% of dry cell weight, resulting in a shorter response to nutrient stress than the OXP strain. Notably, changes in proline and glutamate contents in engineered strains, in particular OXP and OXP/Δadc1, not only partially balanced the intracellular C/N metabolism but also helped cells acclimate under nitrogen (N) and phosphorus (P) stress with higher chlorophyll a content in comparison with wild-type control. CONCLUSIONS In Synechocystis sp. PCC 6803, overexpression of proC resulted in a striking signal to PHB and glycogen accumulation after prolonged nutrient deprivation. When combined with the adc1 disruption, there was a notable increase in PHB production, particularly in situations where there was a strong C supply and a lack of N and P.
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Affiliation(s)
- Suthira Utharn
- Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand
- Program of Biotechnology, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Saowarath Jantaro
- Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.
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3
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Aghaali Z, Naghavi MR. Biotechnological Approaches for Enhancing Polyhydroxyalkanoates (PHAs) Production: Current and Future Perspectives. Curr Microbiol 2023; 80:345. [PMID: 37731015 DOI: 10.1007/s00284-023-03452-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 08/19/2023] [Indexed: 09/22/2023]
Abstract
The benefits of biotechnology are not limited to genetic engineering, but it also displays its great impact on industrial uses of crops (e.g., biodegradable plastics). Polyhydroxyalkanoates (PHAs) make a diverse class of bio-based and biodegradable polymers naturally synthesized by numerous microorganisms. However, several C3 and C4 plants have also been genetically engineered to produce PHAs. The highest production yield of PHAs was obtained with a well-known C3 plant, Arabidopsis thaliana, upto 40% of the dry weight of the leaf. This review summarizes all biotechnological mechanisms that have been adopted with the goal of increasing PHAs production in bacteria and plant species alike. Moreover, the possibility of using some methods that have not been applied in bioplastic science are discussed with special attention to plants. These include producing PHAs in transgenic hairy roots and cell suspension cultures, making transformed bacteria and plants via transposons, constructing an engineered metabolon, and overexpressing of phaP and the ABC operon concurrently. Taken together, that biotechnology will be highly beneficial for reducing plastic pollution through the implementation of biotechnological strategies is taken for granted.
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Affiliation(s)
- Zahra Aghaali
- Department of Genetic and Plant Breeding, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran.
| | - Mohammad Reza Naghavi
- Division of Biotechnology, Department of Agronomy and Plant Breeding, College of Agricultural and Natural Resources, University of Tehran, Karaj, Iran.
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4
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Huang C, Duan X, Ge H, Xiao Z, Zheng L, Wang G, Dong J, Wang Y, Zhang Y, Huang X, An H, Xu W, Wang Y. Parallel Proteomic Comparison of Mutants With Altered Carbon Metabolism Reveals Hik8 Regulation of P II Phosphorylation and Glycogen Accumulation in a Cyanobacterium. Mol Cell Proteomics 2023; 22:100582. [PMID: 37225018 PMCID: PMC10315926 DOI: 10.1016/j.mcpro.2023.100582] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 05/18/2023] [Accepted: 05/19/2023] [Indexed: 05/26/2023] Open
Abstract
Carbon metabolism is central to photosynthetic organisms and involves the coordinated operation and regulation of numerous proteins. In cyanobacteria, proteins involved in carbon metabolism are regulated by multiple regulators including the RNA polymerase sigma factor SigE, the histidine kinases Hik8, Hik31 and its plasmid-borne paralog Slr6041, and the response regulator Rre37. To understand the specificity and the cross-talk of such regulations, we simultaneously and quantitatively compared the proteomes of the gene knockout mutants for the regulators. A number of proteins showing differential expression in one or more mutants were identified, including four proteins that are unanimously upregulated or downregulated in all five mutants. These represent the important nodes of the intricate and elegant regulatory network for carbon metabolism. Moreover, serine phosphorylation of PII, a key signaling protein sensing and regulating in vivo carbon/nitrogen (C/N) homeostasis through reversible phosphorylation, is massively increased with a concomitant significant decrease in glycogen content only in the hik8-knockout mutant, which also displays impaired dark viability. An unphosphorylatable PII S49A substitution restored the glycogen content and rescued the dark viability of the mutant. Together, our study not only establishes the quantitative relationship between the targets and the corresponding regulators and elucidated their specificity and cross-talk but also unveils that Hik8 regulates glycogen accumulation through negative regulation of PII phosphorylation, providing the first line of evidence that links the two-component system with PII-mediated signal transduction and implicates them in the regulation of carbon metabolism.
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Affiliation(s)
- Chengcheng Huang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Xiaoxiao Duan
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Haitao Ge
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Zhen Xiao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Limin Zheng
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Gaojie Wang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Jinghui Dong
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Yan Wang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Yuanya Zhang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Xiahe Huang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Hongyu An
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Wu Xu
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, Louisiana, USA
| | - Yingchun Wang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China.
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5
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Malic Enzyme, not Malate Dehydrogenase, Mainly Oxidizes Malate That Originates from the Tricarboxylic Acid Cycle in Cyanobacteria. mBio 2022; 13:e0218722. [PMID: 36314837 PMCID: PMC9765476 DOI: 10.1128/mbio.02187-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2023] Open
Abstract
Oxygenic photoautotrophic bacteria, cyanobacteria, have the tricarboxylic acid (TCA) cycle, and metabolite production using the cyanobacterial TCA cycle has been spotlighted recently. The unicellular cyanobacterium Synechocystis sp. strain PCC 6803 (Synechocystis 6803) has been used in various studies on the cyanobacterial TCA cycle. Malate oxidation in the TCA cycle is generally catalyzed by malate dehydrogenase (MDH). However, Synechocystis 6803 MDH (SyMDH) is less active than MDHs from other organisms. Additionally, SyMDH uses only NAD+ as a coenzyme, unlike other TCA cycle enzymes from Synechocystis 6803 that use NADP+. These results suggest that MDH rarely catalyzes malate oxidation in the cyanobacterial TCA cycle. Another enzyme catalyzing malate oxidation is malic enzyme (ME). We clarified which enzyme oxidizes malate that originates from the cyanobacterial TCA cycle using analyses focusing on ME and MDH. In contrast to SyMDH, Synechocystis 6803 ME (SyME) showed high activity when NADP+ was used as a coenzyme. Unlike the Synechocystis 6803 mutant lacking SyMDH, the mutant lacking SyME accumulated malate in the cells. ME was more highly preserved in the cyanobacterial genomes than MDH. These results indicate that ME mainly oxidizes malate that originates from the cyanobacterial TCA cycle (named the ME-dependent TCA cycle). The ME-dependent TCA cycle generates NADPH, not NADH. This is consistent with previous reports that NADPH is an electron carrier in the cyanobacterial respiratory chain. Our finding suggests the diversity of enzymes involved in the TCA cycle in the organisms, and analyses such as those performed in this study are necessary to determine the enzymes. IMPORTANCE Oxygenic photoautotrophic bacteria, namely, cyanobacteria, have the tricarboxylic acid (TCA) cycle. Recently, metabolite production using the cyanobacterial TCA cycle has been well studied. To enhance the production volume of metabolites, understanding the biochemical properties of the cyanobacterial TCA cycle is required. Generally, malate dehydrogenase oxidizes malate in the TCA cycle. However, cyanobacterial malate dehydrogenase shows low activity and does not use NADP+ as a coenzyme, unlike other cyanobacterial TCA cycle enzymes. Our analyses revealed that another malate oxidation enzyme, the malic enzyme, mainly oxidizes malate that originates from the cyanobacterial TCA cycle. These findings provide better insights into metabolite production using the cyanobacterial TCA cycle. Furthermore, our findings suggest that the enzymes related to the TCA cycle vary from organism to organism and emphasize the importance of analyses to identify the enzymes such as those performed in this study.
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6
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Doello S, Neumann N, Forchhammer K. Regulatory phosphorylation event of phosphoglucomutase 1 tunes its activity to regulate glycogen metabolism. FEBS J 2022; 289:6005-6020. [PMID: 35509259 DOI: 10.1111/febs.16471] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 03/25/2022] [Accepted: 05/03/2022] [Indexed: 12/24/2022]
Abstract
Regulation of glycogen metabolism is of vital importance in organisms of all three kingdoms of life. Although the pathways involved in glycogen synthesis and degradation are well known, many regulatory aspects around the metabolism of this polysaccharide remain undeciphered. Here, we used the unicellular cyanobacterium Synechocystis as a model to investigate how glycogen metabolism is regulated in nitrogen-starved dormant cells, which entirely rely on glycogen catabolism to resume growth upon nitrogen repletion. We identified phosphoglucomutase 1 (PGM1) as a key regulatory point in glycogen metabolism, and post-translational modification as an essential mechanism for controlling its activity. We could show that PGM1 is phosphorylated ata residue in the regulatory latch domain (Ser 47) during nitrogen starvation, which inhibits its activity. Inactivation of PGM1 by phosphorylation at Ser 47 prevents premature degradation of the glycogen stores and appears to be essential for survival of Synechocystis in the dormant state. Remarkably, this regulatory mechanism seems to be evolutionary conserved in PGM1 enzymes, from bacteria to humans.
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Affiliation(s)
- Sofía Doello
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Germany
| | - Niels Neumann
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Germany
| | - Karl Forchhammer
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Germany
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7
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Cheng A, Harikrishna JA, Redwood CS, Lit LC, Nath SK, Chua KH. Genetics Matters: Voyaging from the Past into the Future of Humanity and Sustainability. Int J Mol Sci 2022; 23:ijms23073976. [PMID: 35409335 PMCID: PMC8999725 DOI: 10.3390/ijms23073976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/21/2022] [Accepted: 03/30/2022] [Indexed: 12/02/2022] Open
Abstract
The understanding of how genetic information may be inherited through generations was established by Gregor Mendel in the 1860s when he developed the fundamental principles of inheritance. The science of genetics, however, began to flourish only during the mid-1940s when DNA was identified as the carrier of genetic information. The world has since then witnessed rapid development of genetic technologies, with the latest being genome-editing tools, which have revolutionized fields from medicine to agriculture. This review walks through the historical timeline of genetics research and deliberates how this discipline might furnish a sustainable future for humanity.
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Affiliation(s)
- Acga Cheng
- Institute of Biological Science, Faculty of Science, Universiti Malaya, Kuala Lumpur 50603, Malaysia; (A.C.); (J.A.H.)
| | - Jennifer Ann Harikrishna
- Institute of Biological Science, Faculty of Science, Universiti Malaya, Kuala Lumpur 50603, Malaysia; (A.C.); (J.A.H.)
- Centre for Research in Biotechnology for Agriculture, University of Malaya, Kuala Lumpur 50603, Malaysia
| | - Charles S. Redwood
- Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK;
| | - Lei Cheng Lit
- Department of Physiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia;
| | - Swapan K. Nath
- Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
- Correspondence: (S.K.N.); (K.H.C.)
| | - Kek Heng Chua
- Department of Biomedical Science, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
- Correspondence: (S.K.N.); (K.H.C.)
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8
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Sirohi R, Lee JS, Yu BS, Roh H, Sim SJ. Sustainable production of polyhydroxybutyrate from autotrophs using CO 2 as feedstock: Challenges and opportunities. BIORESOURCE TECHNOLOGY 2021; 341:125751. [PMID: 34416655 DOI: 10.1016/j.biortech.2021.125751] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/05/2021] [Accepted: 08/07/2021] [Indexed: 05/05/2023]
Abstract
Due to industrialization and rapid increase in world population, the global energy consumption has increased dramatically. As a consequence, there is increased consumption of fossil fuels, leading to a rapid increase in CO2 concentration in the atmosphere. This accumulated CO2 can be efficiently used by autotrophs as a carbon source to produce chemicals and biopolymers. There has been increasing attention on the production of polyhydroxybutyrate (PHB), a biopolymer, with focus on reducing the production cost. For this, cheaper renewable feedstocks, molecular tools, including metabolic and genetic engineering have been explored to improve microbial strains along with process engineering aspects for scale-up of PHB production. This review discusses the recent advents on the utilization of CO2 as feedstock especially by engineered autotrophs, for sustainable production of PHB. The review also discusses the innovations in cultivation technology and process monitoring while understanding the underlying mechanisms for CO2 to biopolymer conversion.
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Affiliation(s)
- Ranjna Sirohi
- Department of Chemical & Biological Engineering, Korea University, Seoul 136713, Republic of Korea
| | - Jeong Seop Lee
- Department of Chemical & Biological Engineering, Korea University, Seoul 136713, Republic of Korea
| | - Byung Sun Yu
- Department of Chemical & Biological Engineering, Korea University, Seoul 136713, Republic of Korea
| | - Hyejin Roh
- Department of Chemical & Biological Engineering, Korea University, Seoul 136713, Republic of Korea
| | - Sang Jun Sim
- Department of Chemical & Biological Engineering, Korea University, Seoul 136713, Republic of Korea.
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9
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Mitra R, Xu T, Chen GQ, Xiang H, Han J. An updated overview on the regulatory circuits of polyhydroxyalkanoates synthesis. Microb Biotechnol 2021; 15:1446-1470. [PMID: 34473895 PMCID: PMC9049629 DOI: 10.1111/1751-7915.13915] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 08/20/2021] [Accepted: 08/23/2021] [Indexed: 11/30/2022] Open
Abstract
Polyhydroxyalkanoates (PHA) are a promising and sustainable alternative to the petroleum‐based synthetic plastics. Regulation of PHA synthesis is receiving considerable importance as engineering the regulatory factors might help developing strains with improved PHA‐producing abilities. PHA synthesis is dedicatedly regulated by a number of regulatory networks. They tightly control the PHA content, granule size and their distribution in cells. Most PHA‐accumulating microorganisms have multiple regulatory networks that impart a combined effect on PHA metabolism. Among them, several factors ranging from global to specific regulators, have been identified and characterized till now. This review is an attempt to categorically summarize the diverse regulatory circuits that operate in some important PHA‐producing microorganisms. However, in several organisms, the detailed mechanisms involved in the regulation of PHA synthesis is not well‐explored and hence further research is needed. The information presented in this review might help researcher to identify the prevailing research gaps in PHA regulation.
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Affiliation(s)
- Ruchira Mitra
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.,International College, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Tong Xu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Guo-Qiang Chen
- Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Hua Xiang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.,College of Life Science, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jing Han
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.,College of Life Science, University of Chinese Academy of Sciences, Beijing, 100049, China
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10
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Utharn S, Yodsang P, Incharoensakdi A, Jantaro S. Cyanobacterium Synechocystis sp. PCC 6803 lacking adc1 gene produces higher polyhydroxybutyrate accumulation under modified nutrients of acetate supplementation and nitrogen-phosphorus starvation. ACTA ACUST UNITED AC 2021; 31:e00661. [PMID: 34386355 PMCID: PMC8342905 DOI: 10.1016/j.btre.2021.e00661] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 07/12/2021] [Accepted: 07/23/2021] [Indexed: 11/28/2022]
Abstract
Increased polyhydroxybutyrate production in cyanobacterium Synechocystis sp. PCC 6803 lacking adc1 gene (Δadc1) is first-timely reported in this study. We constructed the mutant by disrupting adc1 gene encoding arginine decarboxylase, thereby exhibiting a partial blockade of polyamine synthesis. This Δadc1 mutant had a proliferative growth and certain contents of intracellular pigments including chlorophyll a and carotenoids as similar as those of wild type (WT). Highest PHB production was certainly induced by BG11-N-P+A condition in both WT and Δadc1 mutant of about 24.9 %w/DCW at day 9 and 36.1 %w/DCW at day 7 of adaptation time, respectively. Abundant PHB granules were also visualized under both BG11-N-P and BG11-N-P+A conditions. All pha transcript amounts of Δadc1 mutant grown at 7 days-adaptation time were clearly upregulated corresponding to its PHB content under BG11-N-P+A condition. Our finding indicated that this adc1 perturbation is alternatively achieved for PHB production in Synechocystis sp. PCC 6803.
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Key Words
- ADC, arginine decarboxylase
- Adc1 mutant
- DCW, dry cell weight
- DMF, N,N-dimethylformamide
- HPLC, high pressure liquid chromatography
- Nutrient deprivation
- PCR, polymerase chain reaction
- PHAs, polyhydroxyalkanoates
- PHB, polyhydroxybutyrate
- Polyhydroxybutyrate
- Synechocystis sp. PCC6803
- TAE, Tris-acetate-ethylene diamine tetraacetic acid
- TCA, tricarboxylic acid
- h, hour(s)
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Affiliation(s)
- Suthira Utharn
- Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.,Program of Biotechnology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Panutda Yodsang
- Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.,King Mongkut's University of Technology Thonburi Residential College, Ratchaburi, 70150, Thailand
| | - Aran Incharoensakdi
- Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Saowarath Jantaro
- Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
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11
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Sindhu R, Madhavan A, Arun KB, Pugazhendhi A, Reshmy R, Awasthi MK, Sirohi R, Tarafdar A, Pandey A, Binod P. Metabolic circuits and gene regulators in polyhydroxyalkanoate producing organisms: Intervention strategies for enhanced production. BIORESOURCE TECHNOLOGY 2021; 327:124791. [PMID: 33579565 DOI: 10.1016/j.biortech.2021.124791] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/19/2021] [Accepted: 01/23/2021] [Indexed: 06/12/2023]
Abstract
Worldwide worries upsurge concerning environmental pollutions triggered by the accumulation of plastic wastes. Biopolymers are promising candidates for resolving these difficulties by replacing non-biodegradable plastics. Among biopolymers, polyhydroxyalkanoates (PHAs), are natural polymers that are synthesized and accumulated in a range of microorganisms, are considered as promising biopolymers since they have biocompatibility, biodegradability, and other physico-chemical properties comparable to those of synthetic plastics. Consequently, considerable research have been attempted to advance a better understanding of mechanisms related to the metabolic synthesis and characteristics of PHAs and to develop native and recombinant microorganisms that can proficiently produce PHAs comprising desired monomers with high titer and productivity for industrial applications. Recent developments in metabolic engineering and synthetic biology applied to enhance PHA synthesis include, promoter engineering, ribosome-binding site (RBS) engineering, development of synthetic constructs etc. This review gives a brief overview of metabolic routes and regulators of PHA production and its intervention strategies.
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Affiliation(s)
- Raveendran Sindhu
- Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Trivandrum 695 019, Kerala, India
| | - Aravind Madhavan
- Rajiv Gandhi Centre for Biotechnology, Trivandrum 695 014, Kerala, India
| | - K B Arun
- Rajiv Gandhi Centre for Biotechnology, Trivandrum 695 014, Kerala, India
| | - Arivalagan Pugazhendhi
- Innovative Green Product Synthesis and Renewable Environment Development Research Group, Faculty of Environment and Labour Safety, Ton Duc Thang University, Ho Chi Minh City, Viet Nam
| | - R Reshmy
- Post Graduate and Research Department of Chemistry, Bishop Moore College, Mavelikara 690 110, Kerala, India
| | - Mukesh Kumar Awasthi
- College of Natural Resources and Environment, Northwest A & F University, Yangling, Shaanxi Province 712100, PR China
| | - Ranjna Sirohi
- Department of Post Harvest Process and Food Engineering, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand 263 145, India
| | - Ayon Tarafdar
- Divison of Livestock Production and Management, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly 243 122, Uttar Pradesh, India
| | - Ashok Pandey
- Centre for Innovation and Translational Research, CSIR- Indian Institute for Toxicology Research (CSIR-IITR), 31 MG Marg, Lucknow 226 001, India
| | - Parameswaran Binod
- Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Trivandrum 695 019, Kerala, India.
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12
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Neumann N, Doello S, Forchhammer K. Recovery of Unicellular Cyanobacteria from Nitrogen Chlorosis: A Model for Resuscitation of Dormant Bacteria. Microb Physiol 2021; 31:78-87. [PMID: 33878759 DOI: 10.1159/000515742] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 03/06/2021] [Indexed: 11/19/2022]
Abstract
Nitrogen starvation induces developmental transitions in cyanobacteria. Whereas complex multicellular cyanobacteria of the order Nostocales can differentiate specialized cells that perform nitrogen fixation in the presence of oxygenic photosynthesis, non-diazotrophic unicellular strains, such as Synechococcus elongatus or Synechocystis PCC 6803, undergo a transition into a dormant non-growing state. Due to loss of pigments during this acclimation, the process is termed chlorosis. Cells maintain viability in this state for prolonged periods of time, until they encounter a useable nitrogen source, which triggers a highly coordinated awakening process, termed resuscitation. The minimal set of cellular activity that maintains the viability of cells during chlorosis and ensures efficient resuscitation represents the organism's equivalent of the BIOS, the basic input/output system of a computer, that helps "booting" the operation system after switching on. This review summarizes the recent research in the resuscitation of cyanobacteria, representing a powerful model for the awakening of dormant bacteria.
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Affiliation(s)
- Niels Neumann
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Sofia Doello
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Karl Forchhammer
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
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Genetic, Genomics, and Responses to Stresses in Cyanobacteria: Biotechnological Implications. Genes (Basel) 2021; 12:genes12040500. [PMID: 33805386 PMCID: PMC8066212 DOI: 10.3390/genes12040500] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/25/2021] [Accepted: 03/25/2021] [Indexed: 02/07/2023] Open
Abstract
Cyanobacteria are widely-diverse, environmentally crucial photosynthetic prokaryotes of great interests for basic and applied science. Work to date has focused mostly on the three non-nitrogen fixing unicellular species Synechocystis PCC 6803, Synechococcus PCC 7942, and Synechococcus PCC 7002, which have been selected for their genetic and physiological interests summarized in this review. Extensive "omics" data sets have been generated, and genome-scale models (GSM) have been developed for the rational engineering of these cyanobacteria for biotechnological purposes. We presently discuss what should be done to improve our understanding of the genotype-phenotype relationships of these models and generate robust and predictive models of their metabolism. Furthermore, we also emphasize that because Synechocystis PCC 6803, Synechococcus PCC 7942, and Synechococcus PCC 7002 represent only a limited part of the wide biodiversity of cyanobacteria, other species distantly related to these three models, should be studied. Finally, we highlight the need to strengthen the communication between academic researchers, who know well cyanobacteria and can engineer them for biotechnological purposes, but have a limited access to large photobioreactors, and industrial partners who attempt to use natural or engineered cyanobacteria to produce interesting chemicals at reasonable costs, but may lack knowledge on cyanobacterial physiology and metabolism.
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14
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Iijima H, Watanabe A, Sukigara H, Iwazumi K, Shirai T, Kondo A, Osanai T. Four-carbon dicarboxylic acid production through the reductive branch of the open cyanobacterial tricarboxylic acid cycle in Synechocystis sp. PCC 6803. Metab Eng 2021; 65:88-98. [PMID: 33722652 DOI: 10.1016/j.ymben.2021.03.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 02/23/2021] [Accepted: 03/06/2021] [Indexed: 11/18/2022]
Abstract
Succinate, fumarate, and malate are valuable four-carbon (C4) dicarboxylic acids used for producing plastics and food additives. C4 dicarboxylic acid is biologically produced by heterotrophic organisms. However, current biological production requires organic carbon sources that compete with food uses. Herein, we report C4 dicarboxylic acid production from CO2 using metabolically engineered Synechocystis sp. PCC 6803. Overexpression of citH, encoding malate dehydrogenase (MDH), resulted in the enhanced production of succinate, fumarate, and malate. citH overexpression increased the reductive branch of the open cyanobacterial tricarboxylic acid (TCA) cycle flux. Furthermore, product stripping by medium exchanges increased the C4 dicarboxylic acid levels; product inhibition and acidification of the media were the limiting factors for succinate production. Our results demonstrate that MDH is a key regulator that activates the reductive branch of the open cyanobacterial TCA cycle. The study findings suggest that cyanobacteria can act as a biocatalyst for converting CO2 to carboxylic acids.
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Affiliation(s)
- Hiroko Iijima
- School of Agriculture, Meiji University, 1-1-1, Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan
| | - Atsuko Watanabe
- School of Agriculture, Meiji University, 1-1-1, Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan
| | - Haruna Sukigara
- School of Agriculture, Meiji University, 1-1-1, Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan
| | - Kaori Iwazumi
- School of Agriculture, Meiji University, 1-1-1, Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan
| | - Tomokazu Shirai
- Center for Sustainable Resource Science, RIKEN, 1-7-22, Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
| | - Akihiko Kondo
- Center for Sustainable Resource Science, RIKEN, 1-7-22, Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan; Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
| | - Takashi Osanai
- School of Agriculture, Meiji University, 1-1-1, Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan.
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15
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Kang MJ, Hong SJ, Yoo D, Cho BK, Lee H, Choi HK, Kim DM, Lee CG. Photosynthetic production of biodiesel in Synechocystis sp. PCC6803 transformed with insect or plant fatty acid methyltransferase. Bioprocess Biosyst Eng 2021; 44:1433-1439. [PMID: 33656615 DOI: 10.1007/s00449-021-02520-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 01/25/2021] [Indexed: 01/10/2023]
Abstract
Biodiesel contains methyl or ethyl esters of long-chain fatty acids and has recently attracted increasing attention. Microalgae have emerged as a sustainable biodiesel production system owing to their photosynthetic potential. However, the conversion of microalgal biomass to biodiesel requires high energy and is costly. This study aimed to overcome the high cost of the pretreatment process by generating cyanobacteria converting fatty acids to fatty acids methyl ester (FAME) in vivo by introducing the fatty acid methyl ester transferase (FAMT) gene. Two FAMT genes from Drosophila melanogaster and Arabidopsis thaliana were selected and their codons were optimized for insertion in the Synechocystis sp. PCC6803 genome through homologous recombination, respectively. FAMT mRNA and protein expression levels were confirmed through reverse-transcription PCR and western blot analysis, respectively. Furthermore, heterologous expression of the FAMT genes yielded FAME, which was analyzed by gas chromatography. We found that FAMT transformants can be further metabolically optimized and applied for commercial production of biodiesel.
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Affiliation(s)
- Mi-Jin Kang
- Department of Biological Engineering, Inha University, Incheon, 22212, Republic of Korea
| | - Seong-Joo Hong
- Department of Biological Engineering, Inha University, Incheon, 22212, Republic of Korea
| | - Danbi Yoo
- Department of Biological Engineering, Inha University, Incheon, 22212, Republic of Korea
| | - Byung-Kwan Cho
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, 34051, Republic of Korea
| | - Hookeun Lee
- College of Pharmacy, Gachon University, Incheon, 21936, Republic of Korea
| | - Hyung-Kyoon Choi
- College of Pharmacy, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Dong-Myung Kim
- Department of Fine Chemical Engineering and Applied Chemistry, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Choul-Gyun Lee
- Department of Biological Engineering, Inha University, Incheon, 22212, Republic of Korea.
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Koch M, Bruckmoser J, Scholl J, Hauf W, Rieger B, Forchhammer K. Maximizing PHB content in Synechocystis sp. PCC 6803: a new metabolic engineering strategy based on the regulator PirC. Microb Cell Fact 2020; 19:231. [PMID: 33353555 PMCID: PMC7756911 DOI: 10.1186/s12934-020-01491-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/02/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND PHB (poly-hydroxy-butyrate) represents a promising bioplastic alternative with good biodegradation properties. Furthermore, PHB can be produced in a completely carbon-neutral fashion in the natural producer cyanobacterium Synechocystis sp. PCC 6803. This strain has been used as model system in past attempts to boost the intracellular production of PHB above ~ 15% per cell-dry-weight (CDW). RESULTS We have created a new strain that lacks the regulatory protein PirC (product of sll0944), which exhibits a higher activity of the phosphoglycerate mutase resulting in increased PHB pools under nutrient limiting conditions. To further improve the intracellular PHB content, two genes involved in PHB metabolism, phaA and phaB, from the known producer strain Cupriavidus necator, were introduced under the control of the strong promotor PpsbA2. The resulting strain, termed PPT1 (ΔpirC-REphaAB), produced high amounts of PHB under continuous light as well under a day-night regime. When grown in nitrogen and phosphorus depleted medium, the cells produced up to 63% per CDW. Upon the addition of acetate, the content was further increased to 81% per CDW. The produced polymer consists of pure PHB, which is highly isotactic. CONCLUSION The amounts of PHB achieved with PPT1 are the highest ever reported in any known cyanobacterium and demonstrate the potential of cyanobacteria for a sustainable, industrial production of PHB.
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Affiliation(s)
- Moritz Koch
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Eberhard-Karls-Universität Tübingen, Tübingen, Germany
| | - Jonas Bruckmoser
- Wacker-Chair of Macromolecular Chemistry, TUM Department of Chemistry, Technical University of Munich, Munich, Germany
| | - Jörg Scholl
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Eberhard-Karls-Universität Tübingen, Tübingen, Germany
| | - Waldemar Hauf
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Eberhard-Karls-Universität Tübingen, Tübingen, Germany
| | - Bernhard Rieger
- Wacker-Chair of Macromolecular Chemistry, TUM Department of Chemistry, Technical University of Munich, Munich, Germany
| | - Karl Forchhammer
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Eberhard-Karls-Universität Tübingen, Tübingen, Germany.
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Srivastava A, Varshney RK, Shukla P. Sigma Factor Modulation for Cyanobacterial Metabolic Engineering. Trends Microbiol 2020; 29:266-277. [PMID: 33229204 DOI: 10.1016/j.tim.2020.10.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 10/25/2020] [Accepted: 10/26/2020] [Indexed: 11/18/2022]
Abstract
Sigma (σ) factors are key regulatory proteins that control the transcription initiation in prokaryotes. In response to environmental or developmental cues, σ factors initiate the transcription of necessary genes responsible for maintaining a life-sustaining metabolic balance. Due to the significant role of σ factors in bacterial metabolism, their rational engineering for commercial metabolite production in photoautotrophic, cyanobacterial cells is a desirable venture. As cyanobacterial genomes typically encode multiple σ factors, effective execution of metabolic engineering efforts largely relies on uncovering the complicated gene regulatory network and further characterization of the members of σ factor regulatory circuits. This review outlines the prospects of σ factor in metabolic engineering of cyanobacteria, summarizes the challenges in the path towards an efficient strain construction and highlights the genomic context of putative regulators of cyanobacterial σ factors.
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Affiliation(s)
- Amit Srivastava
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA
| | - Rajeev K Varshney
- Center of Excellence in Genomics and Systems Biology, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, India
| | - Pratyoosh Shukla
- Enzyme Technology and Protein Bioinformatics Laboratory, Department of Microbiology, Maharshi Dayanand University, Rohtak-124001, Haryana, India.
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Modifying the Cyanobacterial Metabolism as a Key to Efficient Biopolymer Production in Photosynthetic Microorganisms. Int J Mol Sci 2020; 21:ijms21197204. [PMID: 33003478 PMCID: PMC7582838 DOI: 10.3390/ijms21197204] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 09/26/2020] [Accepted: 09/28/2020] [Indexed: 12/22/2022] Open
Abstract
Cyanobacteria are photoautotrophic bacteria commonly found in the natural environment. Due to the ecological benefits associated with the assimilation of carbon dioxide from the atmosphere and utilization of light energy, they are attractive hosts in a growing number of biotechnological processes. Biopolymer production is arguably one of the most critical areas where the transition from fossil-derived chemistry to renewable chemistry is needed. Cyanobacteria can produce several polymeric compounds with high applicability such as glycogen, polyhydroxyalkanoates, or extracellular polymeric substances. These important biopolymers are synthesized using precursors derived from central carbon metabolism, including the tricarboxylic acid cycle. Due to their unique metabolic properties, i.e., light harvesting and carbon fixation, the molecular and genetic aspects of polymer biosynthesis and their relationship with central carbon metabolism are somehow different from those found in heterotrophic microorganisms. A greater understanding of the processes involved in cyanobacterial metabolism is still required to produce these molecules more efficiently. This review presents the current state of the art in the engineering of cyanobacterial metabolism for the efficient production of these biopolymers.
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19
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Kizawa A, Osanai T. Overexpression of the response regulator rpaA causes an impaired cell division in the Cyanobacterium Synechocystis sp. PCC 6803. J GEN APPL MICROBIOL 2020; 66:121-128. [PMID: 32173680 DOI: 10.2323/jgam.2020.01.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In photosynthetic microorganisms, cell cycle progression depends on day and night cycles; however, how cell division is regulated in response to these environmental changes is poorly understood. RpaA has been implicated in the signal output from both circadian clocks and light/dark conditions in the unicellular spherical-celled cyanobacterium Synechocystis sp. PCC 6803. In the present study, we investigated the involvement of a two-component response regulator RpaA in cell division regulation. Firstly, we examined the effects of rpaA overexpression on cell morphology and the expression levels of cell division genes. We observed an increase in the volume of non-dividing cells and a high proportion of dividing cells in rpaA-overexpressing strains by light microscopy. The expression levels of selected cell division-related genes were higher in the rpaA-overexpressing strain than in the wild type, including minD of the Min system; cdv3 and zipN, which encode two divisome components; and murB, murC, and pbp2, which are involved in peptidoglycan (PG) synthesis. Moreover, in the rpaA-overexpressing strain, the outer membrane and cell wall PG layer were not smooth, and the outer membrane was not clearly visible by transmission electron microscopy. These results demonstrated that rpaA overexpression causes an impaired cell division, which is accompanied by transcriptional activation of cell division genes and morphological changes in the PG layer and outer membrane.
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Affiliation(s)
- Ayumi Kizawa
- Department of Agricultural Chemistry, School of Agriculture, Meiji University
| | - Takashi Osanai
- Department of Agricultural Chemistry, School of Agriculture, Meiji University
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20
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Wu D, Wang Y, Xu X. Effects of a Type I RM System on Gene Expression and Glycogen Catabolism in Synechocystis sp. PCC 6803. Front Microbiol 2020; 11:1258. [PMID: 32582132 PMCID: PMC7296061 DOI: 10.3389/fmicb.2020.01258] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 05/18/2020] [Indexed: 01/25/2023] Open
Abstract
Increasing evidence has shown that DNA methylation is involved in gene regulation in prokaryotes. However, there have been very limited reports about the role of DNA methylation in regulation of gene expression and physiological functions in cyanobacteria. In Synechocystis sp. PCC 6803, four genes on the plasmid pSYSX are predicted to encode the type I restriction-methylation system, slr6095 and slr6096 for the M subunit, slr6097 for the S subunit and slr6102 for the R subunit. Compared to the wild type, slr6095, slr6096, and slr6097 mutants lacked the GGm6AN7TTGG/CCAm6AN7TCC methylation in genomic DNA. Transcriptomic analysis indicated that 171 genes were reproducibly up- or down-regulated in all three mutants relative to the wild type. The changed expression of some genes, including sll1356 for glycogen phosphorylase (GlgP), was associated with the loss of GGm6AN7TTGG/CCAm6AN7TCC methylation in the coding regions or the upstream non-coding sequences. Inactivation of slr6095, slr6096, or slr6097 increased the expression of sll1356 and the GlgP activity but lowered the glycogen content. These results indicated that the DNA methylation by a type I RM system could alter the expression of certain genes and physiological functions in Synechocystis sp. PCC 6803.
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Affiliation(s)
- Dongqing Wu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of the Chinese Academy of Sciences, Beijing, China
| | - Yali Wang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Xudong Xu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
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21
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Cyanobacterial sigma factors: Current and future applications for biotechnological advances. Biotechnol Adv 2020; 40:107517. [DOI: 10.1016/j.biotechadv.2020.107517] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 01/07/2020] [Accepted: 01/09/2020] [Indexed: 11/15/2022]
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22
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Velázquez-Sánchez C, Espín G, Peña C, Segura D. The Modification of Regulatory Circuits Involved in the Control of Polyhydroxyalkanoates Metabolism to Improve Their Production. Front Bioeng Biotechnol 2020; 8:386. [PMID: 32426348 PMCID: PMC7204398 DOI: 10.3389/fbioe.2020.00386] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 04/07/2020] [Indexed: 11/13/2022] Open
Abstract
Poly-(3-hydroxyalkanoates) (PHAs) are bacterial carbon and energy storage compounds. These polymers are synthesized under conditions of nutritional imbalance, where a nutrient is growth-limiting while there is still enough carbon source in the medium. On the other side, the accumulated polymer is mobilized under conditions of nutrient accessibility or by limitation of the carbon source. Thus, it is well known that the accumulation of PHAs is affected by the availability of nutritional resources and this knowledge has been used to establish culture conditions favoring high productivities. In addition to this effect of the metabolic status on PHAs accumulation, several genetic regulatory networks have been shown to drive PHAs metabolism, so the expression of the PHAs genes is under the influence of global or specific regulators. These regulators are thought to coordinate PHAs synthesis and mobilization with the rest of bacterial physiology. While the metabolic and biochemical knowledge related to the biosynthesis of these polymers has led to the development of processes in bioreactors for high-level production and also to the establishment of strategies for metabolic engineering for the synthesis of modified biopolymers, the use of knowledge related to the regulatory circuits controlling PHAs metabolism for strain improvement is scarce. A better understanding of the genetic control systems involved could serve as the foundation for new strategies for strain modification in order to increase PHAs production or to adjust the chemical structure of these biopolymers. In this review, the regulatory systems involved in the control of PHAs metabolism are examined, with emphasis on those acting at the level of expression of the enzymes involved and their potential modification for strain improvement, both for higher titers, or manipulation of polymer properties. The case of the PHAs producer Azotobacter vinelandii is taken as an example of the complexity and variety of systems controlling the accumulation of these interesting polymers in response to diverse situations, many of which could be engineered to improve PHAs production.
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Affiliation(s)
- Claudia Velázquez-Sánchez
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Guadalupe Espín
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Carlos Peña
- Departamento Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Daniel Segura
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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Iijima H, Watanabe A, Sukigara H, Shirai T, Kondo A, Osanai T. Simultaneous increases in the levels of compatible solutes by cost-effective cultivation of Synechocystis sp. PCC 6803. Biotechnol Bioeng 2020; 117:1649-1660. [PMID: 32129469 DOI: 10.1002/bit.27324] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 01/27/2020] [Accepted: 03/03/2020] [Indexed: 12/27/2022]
Abstract
Synechocystis sp. PCC 6803, a cyanobacterium widely used for basic research, is often cultivated in a synthetic medium, BG-11, in the presence of 4-(2-hydroxyethyl)-1-piperazine ethanesulfonic acid (HEPES) or 2-[[1,3-dihydroxy-2-(hydroxymethyl)propan-2-yl]amino]ethanesulfonic acid buffer. Owing to the high cost of HEPES buffer (96.9% of the total cost of BG-11 medium), the biotechnological application of BG-11 is limited. In this study, we cultured Synechocystis sp. PCC 6803 cells in BG-11 medium without HEPES buffer and examined the effects on the primary metabolism. Synechocystis sp. PCC 6803 cells could grow in BG-11 medium without HEPES buffer after adjusting for nitrogen sources and light intensity; the production rate reached 0.54 g cell dry weight·L-1 ·day-1 , exceeding that of commercial cyanobacteria and Synechocystis sp. PCC 6803 cells cultivated under other conditions. The exclusion of HEPES buffer markedly altered the metabolites in the central carbon metabolism; particularly, the levels of compatible solutes, such as sucrose, glucosylglycerol, and glutamate were increased. Although the accumulation of sucrose and glucosylglycerol under high salt conditions is antagonistic to each other, these metabolites accumulated simultaneously in cells grown in the cost-effective medium. Because these metabolites are used in industrial feedstocks, our results reveal the importance of medium composition for the production of metabolites using cyanobacteria.
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Affiliation(s)
- Hiroko Iijima
- Department of Agricultural Chemistrym School of Agriculture, Meiji University, Kawasaki, Kanagawa, Japan
| | - Atsuko Watanabe
- Department of Agricultural Chemistrym School of Agriculture, Meiji University, Kawasaki, Kanagawa, Japan
| | - Haruna Sukigara
- Department of Agricultural Chemistrym School of Agriculture, Meiji University, Kawasaki, Kanagawa, Japan
| | - Tomokazu Shirai
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, Japan
| | - Akihiko Kondo
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, Japan.,Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, Kobe, Japan
| | - Takashi Osanai
- Department of Agricultural Chemistrym School of Agriculture, Meiji University, Kawasaki, Kanagawa, Japan
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Hirai K, Nojo M, Sato Y, Tsuzuki M, Sato N. Contribution of protein synthesis depression to poly-β-hydroxybutyrate accumulation in Synechocystis sp. PCC 6803 under nutrient-starved conditions. Sci Rep 2019; 9:19944. [PMID: 31882765 PMCID: PMC6934822 DOI: 10.1038/s41598-019-56520-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 12/11/2019] [Indexed: 12/24/2022] Open
Abstract
Poly-β-hydroxybutyrate (PHB) in cyanobacteria, which accumulates as energy and carbon sources through the action of photosynthesis, is expected to substitute for petroleum-based plastics. This study first demonstrated that PHB accumulation was induced, with the appearance of lipid droplets, in sulfur (S)-starved cells of a cyanobacterium, Synechocystis sp. PCC 6803, however, to a lower level than in nitrogen (N)- or phosphorus (P)-starved cells. Concomitantly found was repression of the accumulation of total cellular proteins in the S-starved cells to a similar level to that in N-starved cells, and a severer level than in P-starved cells. Intriguingly, PHB accumulation was induced in Synechocystis even under nutrient-replete conditions, upon repression of the accumulation of total cellular proteins through treatment of the wild type cells with a protein synthesis inhibitor, chloramphenicol, or through disruption of the argD gene for Arg synthesis. Meanwhile, the expression of the genes for PHB synthesis was hardly induced in S-starved cells, in contrast to their definite up-regulation in N- or P-starved cells. It therefore seemed that PHB accumulation in S-starved cells is achieved through severe repression of protein synthesis, but is smaller than in N- or P-starved cells, owing to little induction of the expression of PHB synthesis genes.
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Affiliation(s)
- Kazuho Hirai
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, 192-0392, Japan
| | - Miki Nojo
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, 192-0392, Japan
| | - Yosuke Sato
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, 192-0392, Japan
| | - Mikio Tsuzuki
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, 192-0392, Japan
| | - Norihiro Sato
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, 192-0392, Japan.
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26
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Arisaka S, Terahara N, Oikawa A, Osanai T. Increased polyhydroxybutyrate levels by ntcA overexpression in Synechocystis sp. PCC 6803. ALGAL RES 2019. [DOI: 10.1016/j.algal.2019.101565] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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PHB is Produced from Glycogen Turn-over during Nitrogen Starvation in Synechocystis sp. PCC 6803. Int J Mol Sci 2019; 20:ijms20081942. [PMID: 31010017 PMCID: PMC6514691 DOI: 10.3390/ijms20081942] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 04/17/2019] [Accepted: 04/18/2019] [Indexed: 12/17/2022] Open
Abstract
Polyhydroxybutyrate (PHB) is a polymer of great interest as a substitute for conventional plastics, which are becoming an enormous environmental problem. PHB can be produced directly from CO2 in photoautotrophic cyanobacteria. The model cyanobacterium Synechocystis sp. PCC 6803 produces PHB under conditions of nitrogen starvation. However, it is so far unclear which metabolic pathways provide the precursor molecules for PHB synthesis during nitrogen starvation. In this study, we investigated if PHB could be derived from the main intracellular carbon pool, glycogen. A mutant of the major glycogen phosphorylase, GlgP2 (slr1367 product), was almost completely impaired in PHB synthesis. Conversely, in the absence of glycogen synthase GlgA1 (sll0945 product), cells not only produced less PHB, but were also impaired in acclimation to nitrogen depletion. To analyze the role of the various carbon catabolic pathways (EMP, ED and OPP pathways) for PHB production, mutants of key enzymes of these pathways were analyzed, showing different impact on PHB synthesis. Together, this study clearly indicates that PHB in glycogen-producing Synechocystis sp. PCC 6803 cells is produced from this carbon-pool during nitrogen starvation periods. This knowledge can be used for metabolic engineering to get closer to the overall goal of a sustainable, carbon-neutral bioplastic production.
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Ito S, Koyama N, Osanai T. Citrate synthase from Synechocystis is a distinct class of bacterial citrate synthase. Sci Rep 2019; 9:6038. [PMID: 30988396 PMCID: PMC6465352 DOI: 10.1038/s41598-019-42659-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 04/04/2019] [Indexed: 12/03/2022] Open
Abstract
Citrate synthase (CS, EC 2.3.3.1) catalyses the initial reaction of the tricarboxylic acid (TCA) cycle. Although CSs from heterotrophic bacteria have been extensively studied, cyanobacterial CSs are not well-understood. Cyanobacteria can produce various metabolites from carbon dioxide. Synechocystis sp. PCC 6803 (Synechocystis 6803) is a cyanobacterium used to synthesize metabolites through metabolic engineering techniques. The production of acetyl-CoA-derived metabolites in Synechocystis 6803 has been widely examined. However, the biochemical mechanisms of reactions involving acetyl-CoA in Synechocystis 6803 are poorly understood. We characterised the CS from Synechocystis 6803 (SyCS) and compared its characteristics with other bacterial CSs. SyCS catalysed only the generation of citrate, and did not catalyse the cleavage of citrate. It is suggested that SyCS is not related to the reductive TCA cycle. The substrate affinity and turnover number of SyCS were lower than those of CSs from heterotrophic bacteria. SyCS was activated by MgCl2 and CaCl2, which inhibit various bacterial CSs. SyCS was not inhibited by ATP and NADH; which are typical feedback inhibitors of other bacterial CSs. SyCS was inhibited by phosphoenolpyruvate and activated by ADP, which has not been reported for CSs from heterotrophic bacteria. Thus, SyCS showed unique characteristics, particularly its sensitivity to effectors.
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Affiliation(s)
- Shoki Ito
- School of Agriculture, Meiji University, 1-1-1, Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan
| | - Naoto Koyama
- School of Agriculture, Meiji University, 1-1-1, Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan
| | - Takashi Osanai
- School of Agriculture, Meiji University, 1-1-1, Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan.
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Carbon Fate and Flux in Prochlorococcus under Nitrogen Limitation. mSystems 2019; 4:mSystems00254-18. [PMID: 30834330 PMCID: PMC6392094 DOI: 10.1128/msystems.00254-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 01/28/2019] [Indexed: 11/20/2022] Open
Abstract
Primary production by Prochlorococcus, the smallest known free-living photosynthetic organism in terms of both physical and genomic size, is thought to have a significant role in global carbon cycles. Despite its small size and low growth rate, Prochlorococcus numerically dominates the phytoplankton community in the nutrient-poor oligotrophic ocean, the largest biome of the Earth's surface. How nutrient limitation, and nitrogen limitation in particular, affects the fate and flux of carbon fixed by Prochlorococcus is currently unknown. To address this gap in knowledge, we compared the bulk rates of photosynthesis and organic carbon release, the concentrations of intracellular metabolites, and the rates of assimilated carbon into the metabolite pools between replete and N-limited chemostat cultures. Total photosynthesis of our N-limited cultures was less than half of those observed in replete cultures, and nitrogen limitation also appears to cause a larger proportion of total fixed carbon to be released to the environment. Our data suggest this occurs in concert with the maintenance of large slow-moving pools of metabolites, including nitrogen-rich molecules such as glutamate. Additionally, we report field data suggesting metabolisms of Prochlorococcus are comparable to results we observe in our laboratory studies. Accounting for these observations, potential metabolic mechanisms utilized by Prochlorococcus are discussed as we build upon our understanding of nutrient-limited photosynthesis and carbon metabolism. IMPORTANCE Photosynthetic microbes are the predominant sources of organic carbon in the sunlit regions of the ocean. During photosynthesis, nitrogen and carbon metabolism are coordinated to synthesize nitrogen-containing organics such as amino acids and nucleic acids. In large regions of the ocean, nitrogen is thought to limit the growth of phytoplankton. The impact of nitrogen limitation on the synthesis of organic carbon is not well understood, especially for the most abundant photosynthetic organism in the nitrogen-limited regions of the ocean, Prochlorococcus. This study compares the carbon metabolism of nitrogen-replete and nitrogen-limited Prochlorococcus spp. to determine how nitrogen availability influences inorganic carbon assimilation into an organic form. Metabolomics and physiological data revealed that cells under nitrogen limitation have reduced metabolic flux and total carbon fixation rates while maintaining elevated metabolite pool levels and releasing a larger proportion of total fixed carbon to the environment.
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Ito S, Osanai T. Single Amino Acid Change in 6-Phosphogluconate Dehydrogenase from Synechocystis Conveys Higher Affinity for NADP+ and Altered Mode of Inhibition by NADPH. PLANT & CELL PHYSIOLOGY 2018; 59:2452-2461. [PMID: 30107441 DOI: 10.1093/pcp/pcy165] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 08/07/2018] [Indexed: 06/08/2023]
Abstract
In the oxidative pentose phosphate pathway, 6-phosphogluconate dehydrogenase (6PGDH; EC 1.1.1.44) is one of the enzymes that catalyzes reactions generating NADPH. The model cyanobacterium Synechocystis sp. PCC 6803 is widely studied for numerous applications; however, biochemical knowledge of the NADPH production pathway in Synechocystis sp. PCC 6803 is limited. In this study, we conducted biochemical analysis of a 6-phosphogluconate dehydrogenase from Synechocystis sp. PCC 6803 (Sy6PGDH). We found that Sy6PGDH has unconventional characteristics, i.e. the highest kcat value and non-competitive inhibition by NADPH. Additionally, phylogenetic analysis of cyanobacterial 6PGDHs revealed that an amino acid residue at position 42 in Sy6PGDH is highly conserved for each order of cyanobacteria, but Sy6PGDH is phylogenetically unique. In Sy6PGDH, a single amino acid substitution at position 42 from serine to threonine enhanced the affinity for NADP+ and altered the mode of inhibition by NADPH. The amino acid substitution equivalent to Ser42 also altered the affinity for NADP+ and mode of inhibition by NADPH in Arthrospira platensis. These data suggested that an amino acid residue corresponding to position 42 in Sy6PGDH is one of the important residues that possibly determines the function of cyanobacterial 6PGDHs.
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Affiliation(s)
- Shoki Ito
- Department of Agricultural Chemistry School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama-ku Kawasaki, Kanagawa, Japan
| | - Takashi Osanai
- Department of Agricultural Chemistry School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama-ku Kawasaki, Kanagawa, Japan
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Forchhammer K, Schwarz R. Nitrogen chlorosis in unicellular cyanobacteria – a developmental program for surviving nitrogen deprivation. Environ Microbiol 2018; 21:1173-1184. [DOI: 10.1111/1462-2920.14447] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/04/2018] [Accepted: 10/09/2018] [Indexed: 11/29/2022]
Affiliation(s)
- Karl Forchhammer
- Interfaculty Institute of Microbiology and Infection Medicine, University Tübingen Auf der Morgenstelle 28, 72076 Tübingen Germany
| | - Rakefet Schwarz
- The Mina & Everard Goodman Faculty of Life SciencesBar‐Ilan University Ramat‐Gan 5290002 Israel
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Production of Bioplastic Compounds by Genetically Manipulated and Metabolic Engineered Cyanobacteria. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1080:155-169. [DOI: 10.1007/978-981-13-0854-3_7] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Takeya M, Iijima H, Sukigara H, Osanai T. Cluster-Level Relationships of Genes Involved in Carbon Metabolism in Synechocystis sp. PCC 6803: Development of a Novel Succinate-Producing Strain. PLANT & CELL PHYSIOLOGY 2018; 59:72-81. [PMID: 29069477 DOI: 10.1093/pcp/pcx162] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 10/19/2017] [Indexed: 06/07/2023]
Abstract
We quantified the transcript levels of 44 genes related to sugar catabolism in strains with altered primary carbon metabolism and discovered a consistent expression pattern among succinate-producing mutants. To identify factors that determine the expression pattern, we calculated Pearson's correlation coefficients, using the transcript data. Correlation analysis revealed positive and negative correlations among genes encoding sugar catabolic enzymes. On the basis of this analysis, we found that the mutant overexpressing both rre37 (encoding an OmpR-type response regulator) and sigE (encoding an RNA polymerase sigma factor) produced increased levels of succinate under dark, anaerobic conditions, with a maximum productivity of 420 mg l-1.
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Affiliation(s)
- Masahiro Takeya
- Department of Agricultural Chemistry, School of Agriculture, Meiji University, 1-1-1, Higashimita, Tamaku, Kawasaki, Kanagawa, 214-8571 Japan
| | - Hiroko Iijima
- Department of Agricultural Chemistry, School of Agriculture, Meiji University, 1-1-1, Higashimita, Tamaku, Kawasaki, Kanagawa, 214-8571 Japan
| | - Haruna Sukigara
- Department of Agricultural Chemistry, School of Agriculture, Meiji University, 1-1-1, Higashimita, Tamaku, Kawasaki, Kanagawa, 214-8571 Japan
| | - Takashi Osanai
- Department of Agricultural Chemistry, School of Agriculture, Meiji University, 1-1-1, Higashimita, Tamaku, Kawasaki, Kanagawa, 214-8571 Japan
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Ehira S, Shimmori Y, Watanabe S, Kato H, Yoshikawa H, Ohmori M. The nitrogen-regulated response regulator NrrA is a conserved regulator of glycogen catabolism in β-cyanobacteria. Microbiology (Reading) 2017; 163:1711-1719. [DOI: 10.1099/mic.0.000549] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Shigeki Ehira
- Department of Biological Science, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
- Department of Biological Sciences, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Ohsawa, Hachioji, Tokyo 192-0397, Japan
| | - Yuka Shimmori
- Department of Biological Sciences, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Ohsawa, Hachioji, Tokyo 192-0397, Japan
| | - Satoru Watanabe
- Department of Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Hiroaki Kato
- Department of Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Hirofumi Yoshikawa
- Department of Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Masayuki Ohmori
- Department of Biological Science, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
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Ueno K, Sakai Y, Shono C, Sakamoto I, Tsukakoshi K, Hihara Y, Sode K, Ikebukuro K. Applying a riboregulator as a new chromosomal gene regulation tool for higher glycogen production in Synechocystis sp. PCC 6803. Appl Microbiol Biotechnol 2017; 101:8465-8474. [PMID: 29038975 DOI: 10.1007/s00253-017-8570-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Revised: 09/18/2017] [Accepted: 09/26/2017] [Indexed: 11/29/2022]
Abstract
Cyanobacteria are one of the most attractive hosts for biofuel production; however, genetic approaches to regulate specific chromosomal genes in cyanobacteria remain limited. With the aim of developing a novel method to regulate chromosomal gene expression in cyanobacteria, we focused on riboregulatory technology. Riboregulators are composed of two RNA fragments whose interaction leads to target gene regulation with high specificity. In this study, we inserted a riboregulator sequence upstream of the chromosomal gene encoding AbrB-like transcriptional regulator, cyAbrB2, to investigate the utility of this tool. The inserted riboregulator was able to regulate cyabrB2 gene expression, with a high ON-OFF ratio up to approximately 50-fold. The transcription levels of several genes for which cyAbrB2 acts as a transcriptional upregulator were also decreased. Further, the cyAbrB2 expression-repressed mutant showed high glycogen accumulation, equivalent to that in the cyabrB2 deletion mutant (ΔcyabrB2). Phenotypic similarities between the cyabrB2 expression-repressed mutant and the ΔcyabrB2 mutant suggest that the riboregulator can potentially be used as a new chromosomal gene regulation tool in cyanobacteria.
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Affiliation(s)
- Kinuko Ueno
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Yuta Sakai
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Chika Shono
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Ippei Sakamoto
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Kaori Tsukakoshi
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Yukako Hihara
- Graduate School of Science and Engineering, Saitama University, Saitama, 338-8570, Japan
| | - Koji Sode
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Kazunori Ikebukuro
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan.
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Singh AK, Mallick N. Advances in cyanobacterial polyhydroxyalkanoates production. FEMS Microbiol Lett 2017; 364:4107776. [DOI: 10.1093/femsle/fnx189] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Accepted: 09/06/2017] [Indexed: 12/25/2022] Open
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Vavitsas K, Rue EØ, Stefánsdóttir LK, Gnanasekaran T, Blennow A, Crocoll C, Gudmundsson S, Jensen PE. Responses of Synechocystis sp. PCC 6803 to heterologous biosynthetic pathways. Microb Cell Fact 2017; 16:140. [PMID: 28806958 PMCID: PMC5556357 DOI: 10.1186/s12934-017-0757-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 08/09/2017] [Indexed: 11/10/2022] Open
Abstract
Background There are an increasing number of studies regarding genetic manipulation of cyanobacteria to produce commercially interesting compounds. The majority of these works study the expression and optimization of a selected heterologous pathway, largely ignoring the wholeness and complexity of cellular metabolism. Regulation and response mechanisms are largely unknown, and even the metabolic pathways themselves are not fully elucidated. This poses a clear limitation in exploiting the rich biosynthetic potential of cyanobacteria. Results In this work, we focused on the production of two different compounds, the cyanogenic glucoside dhurrin and the diterpenoid 13R-manoyl oxide in Synechocystis PCC 6803. We used genome-scale metabolic modelling to study fluxes in individual reactions and pathways, and we determined the concentrations of key metabolites, such as amino acids, carotenoids, and chlorophylls. This allowed us to identify metabolic crosstalk between the native and the introduced metabolic pathways. Most results and simulations highlight the metabolic robustness of cyanobacteria, suggesting that the host organism tends to keep metabolic fluxes and metabolite concentrations steady, counteracting the effects of the heterologous pathway. However, the amino acid concentrations of the dhurrin-producing strain show an unexpected profile, where the perturbation levels were high in seemingly unrelated metabolites. Conclusions There is a wealth of information that can be derived by combining targeted metabolite identification and computer modelling as a frame of understanding. Here we present an example of how strain engineering approaches can be coupled to ‘traditional’ metabolic engineering with systems biology, resulting in novel and more efficient manipulation strategies. Electronic supplementary material The online version of this article (doi:10.1186/s12934-017-0757-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Konstantinos Vavitsas
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
| | - Emil Østergaard Rue
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
| | | | - Thiyagarajan Gnanasekaran
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark.,ISBP-INSA de Toulouse, Avenue de Rangueil, 31077, Toulouse, France
| | - Andreas Blennow
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
| | - Christoph Crocoll
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
| | - Steinn Gudmundsson
- Center for Systems Biology, University of Iceland, Sturlugata 8, 101, Reykjavik, Iceland
| | - Poul Erik Jensen
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark.
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Osanai T, Park YI, Nakamura Y. Editorial: Biotechnology of Microalgae, Based on Molecular Biology and Biochemistry of Eukaryotic Algae and Cyanobacteria. Front Microbiol 2017; 8:118. [PMID: 28203229 PMCID: PMC5285351 DOI: 10.3389/fmicb.2017.00118] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 01/17/2017] [Indexed: 11/30/2022] Open
Affiliation(s)
| | - Youn-Il Park
- Department of Biological Sciences, Chungnam National University Daejeon, South Korea
| | - Yuki Nakamura
- Institute of Plant and Microbial Biology, Academia Sinica Taipei, Taiwan
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Mo H, Xie X, Zhu T, Lu X. Effects of global transcription factor NtcA on photosynthetic production of ethylene in recombinant Synechocystis sp. PCC 6803. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:145. [PMID: 28592994 PMCID: PMC5460508 DOI: 10.1186/s13068-017-0832-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 05/26/2017] [Indexed: 05/21/2023]
Abstract
BACKGROUND Cyanobacteria are considered potential photosynthetic microbial cell factories for biofuel and biochemical production. Ethylene, one of the most important organic chemicals, has been successfully synthesized in cyanobacteria by introducing an exogenous ethylene-forming enzyme (Efe). However, it remains challenging to significantly improve the biosynthetic efficiency of cyanobacterial ethylene. Genetic modification of transcription factors is a powerful strategy for reprogramming cellular metabolism toward target products. In cyanobacteria, nitrogen control A (NtcA), an important global transcription regulator of primary carbon/nitrogen metabolism, is expected to play a crucial role in ethylene biosynthesis. RESULTS The partial deletion of ntcA (MH021) enhanced ethylene production by 23%, while ntcA overexpression (MH023) in a single-copy efe recombinant Synechocystis (XX76) reduced ethylene production by 26%. Compared to XX76, the Efe protein content increased 1.5-fold in MH021. This result may be due to the release of the negative regulation of NtcA on promoter P cpcB , which controls efe expression. Glycogen content showed a 23% reduction in MH021, and the ratio of intracellular succinate to 2-oxoglutarate (2-OG) increased 4.8-fold. In a four-copy efe recombinant strain with partially deleted ntcA and a modified tricarboxylic acid (TCA) cycle (MH043), a peak specific ethylene production rate of 2463 ± 219 μL L-1 h-1 OD730-1 was achieved, which is higher than previously reported. CONCLUSIONS The effects of global transcription factor NtcA on ethylene synthesis in genetically engineered Synechocystis sp. PCC 6803 were evaluated, and the partial deletion of ntcA enhanced ethylene production in both single-copy and multi-copy efe recombinant Synechocystis strains. Increased Efe expression, accelerated TCA cycling, and redirected carbon flux from glycogen probably account for this improvement. The results show great potential for improving ethylene synthetic efficiency in cyanobacteria by modulating global regulation factors.
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Affiliation(s)
- Huilin Mo
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No. 189 Songling Road, Qingdao, 266101 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Xiaoman Xie
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No. 189 Songling Road, Qingdao, 266101 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Tao Zhu
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No. 189 Songling Road, Qingdao, 266101 China
| | - Xuefeng Lu
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No. 189 Songling Road, Qingdao, 266101 China
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Monshupanee T, Nimdach P, Incharoensakdi A. Two-stage (photoautotrophy and heterotrophy) cultivation enables efficient production of bioplastic poly-3-hydroxybutyrate in auto-sedimenting cyanobacterium. Sci Rep 2016; 6:37121. [PMID: 27845413 PMCID: PMC5109257 DOI: 10.1038/srep37121] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 10/25/2016] [Indexed: 12/31/2022] Open
Abstract
Sustainable production of bioplastics by heterotrophic microbes has been restricted by the limited resources of organic substrates and the energy required for biomass harvest. Here, the easy-to-harvest cyanobacterium (Chlorogloea fritschii TISTR 8527), from which the biomass instantaneously settled to the bottom of liquid culture, was utilized to produce poly-3-hydroxybutyrate (PHB) using a two-stage cultivation strategy. The cells were first pre-grown under normal photoautotrophy to increase their biomass and then recultivated under a heterotrophic condition with a single organic substrate to produce the product. Through optimization of this two-stage cultivation, the mass conversion efficiency of acetate substrate to PHB was obtained at 51 ± 7% (w/w), the comparable level to the theoretical biochemical conversion efficiency of acetate to PHB. This two-stage cultivation that efficiently converted the substrate to the product, concurrent with a reduced culture biomass, may be applicable for the production of other biopolymers by cyanobacteria.
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Affiliation(s)
- Tanakarn Monshupanee
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Palida Nimdach
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Aran Incharoensakdi
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
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Klotz A, Georg J, Bučinská L, Watanabe S, Reimann V, Januszewski W, Sobotka R, Jendrossek D, Hess W, Forchhammer K. Awakening of a Dormant Cyanobacterium from Nitrogen Chlorosis Reveals a Genetically Determined Program. Curr Biol 2016; 26:2862-2872. [DOI: 10.1016/j.cub.2016.08.054] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 08/09/2016] [Accepted: 08/22/2016] [Indexed: 01/09/2023]
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Higuchi-Takeuchi M, Morisaki K, Numata K. A Screening Method for the Isolation of Polyhydroxyalkanoate-Producing Purple Non-sulfur Photosynthetic Bacteria from Natural Seawater. Front Microbiol 2016; 7:1509. [PMID: 27708640 PMCID: PMC5030216 DOI: 10.3389/fmicb.2016.01509] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 09/09/2016] [Indexed: 11/23/2022] Open
Abstract
Polyhydroxyalkanoates (PHAs) are a family of biopolyesters accumulated by a variety of microorganisms as carbon and energy storage under starvation conditions. We focused on marine purple non-sulfur photosynthetic bacteria as host microorganisms for PHA production and developed a method for their isolation from natural seawater. To identify novel PHA-producing marine purple non-sulfur photosynthetic bacteria, natural seawaters were cultured in nutrient-rich medium for purple non-sulfur photosynthetic bacteria, and twelve pink- or red-pigmented colonies were picked up. Gas chromatography mass spectrometry analysis revealed that four isolates synthesized PHA at levels ranging from 0.5 to 24.4 wt% of cell dry weight. The 16S ribosomal RNA sequence analysis revealed that one isolate (HM2) showed 100% identity to marine purple non-sulfur photosynthetic bacteria. In conclusion, we have demonstrated in this study that PHA-producing marine purple non-sulfur photosynthetic bacteria can be isolated from natural seawater under nutrient-rich conditions.
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Affiliation(s)
- Mieko Higuchi-Takeuchi
- Enzyme Research Team, Biomass Engineering Research Division, RIKEN Center for Sustainable Resource Science Wako, Japan
| | - Kumiko Morisaki
- Enzyme Research Team, Biomass Engineering Research Division, RIKEN Center for Sustainable Resource Science Wako, Japan
| | - Keiji Numata
- Enzyme Research Team, Biomass Engineering Research Division, RIKEN Center for Sustainable Resource Science Wako, Japan
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Iijima H, Shirai T, Okamoto M, Pinto F, Tamagnini P, Hasunuma T, Kondo A, Hirai MY, Osanai T. Metabolomics-based analysis revealing the alteration of primary carbon metabolism by the genetic manipulation of a hydrogenase HoxH in Synechocystis sp. PCC 6803. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.06.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Kaewbai-Ngam A, Incharoensakdi A, Monshupanee T. Increased accumulation of polyhydroxybutyrate in divergent cyanobacteria under nutrient-deprived photoautotrophy: An efficient conversion of solar energy and carbon dioxide to polyhydroxybutyrate by Calothrix scytonemicola TISTR 8095. BIORESOURCE TECHNOLOGY 2016; 212:342-347. [PMID: 27130227 DOI: 10.1016/j.biortech.2016.04.035] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 04/08/2016] [Accepted: 04/09/2016] [Indexed: 06/05/2023]
Abstract
The cellular PHB content was determined in 137 strains of cyanobacteria representing 88 species in 26 genera under six photoautotrophic nutrient conditions. One hundred and thirty-four strains were PHB producers. The PHB contents of these 134 strains were subtle under normal growth condition, but were significantly increased in 63 strains under nitrogen deprivation (-N), a higher frequency than with phosphate and/or potassium and all-nutrient deprivation. A high PHB accumulation was not associated with any particular evolutionary groups, but was strain specific. The filamentous Calothrix scytonemicola TISTR 8095 produced 356.5±63.4mg/L PHB under -N from a biomass of 1396.6±66.1mg/L, giving a PHB content of 25.4±3.5% (w/w dry weight). This PHB productivity is equivalent to the CO2 consumption of 729.2±129.8mg/L. The maximum energy conversion from solar energy to PHB obtained by C. scytonemicola TISTR 8095 was 1.42±0.30%.
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Affiliation(s)
- Auratai Kaewbai-Ngam
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Aran Incharoensakdi
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Tanakarn Monshupanee
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
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Deletion of the gene family of small chlorophyll-binding proteins (ScpABCDE) offsets C/N homeostasis in Synechocystis PCC 6803. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:396-407. [DOI: 10.1016/j.bbabio.2015.11.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 11/20/2015] [Accepted: 11/27/2015] [Indexed: 02/03/2023]
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Cyanobacterial chassis engineering for enhancing production of biofuels and chemicals. Appl Microbiol Biotechnol 2016; 100:3401-13. [DOI: 10.1007/s00253-016-7374-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 01/29/2016] [Accepted: 02/01/2016] [Indexed: 10/22/2022]
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47
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Kawahara A, Sato Y, Saito Y, Kaneko Y, Takimura Y, Hagihara H, Hihara Y. Free fatty acid production in the cyanobacterium Synechocystis sp. PCC 6803 is enhanced by deletion of the cyAbrB2 transcriptional regulator. J Biotechnol 2016; 220:1-11. [DOI: 10.1016/j.jbiotec.2015.12.035] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 11/30/2015] [Accepted: 12/21/2015] [Indexed: 12/16/2022]
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Shirai T, Osanai T, Kondo A. Designing intracellular metabolism for production of target compounds by introducing a heterologous metabolic reaction based on a Synechosystis sp. 6803 genome-scale model. Microb Cell Fact 2016; 15:13. [PMID: 26783098 PMCID: PMC4717628 DOI: 10.1186/s12934-016-0416-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Accepted: 01/07/2016] [Indexed: 12/18/2022] Open
Abstract
Background Designing optimal intracellular metabolism is essential for using microorganisms to produce useful compounds. Computerized calculations for flux balance analysis utilizing a genome-scale model have been performed for such designs. Many genome-scale models have been developed for different microorganisms. However, optimal designs of intracellular metabolism aimed at producing a useful compound often utilize metabolic reactions of only the host microbial cells. In the present study, we added reactions other than the metabolic reactions with Synechosystis sp. 6803 as a host to its genome-scale model, and constructed a metabolic model of hybrid cells (SyHyMeP) using computerized analysis. Using this model provided a metabolic design that improves the theoretical yield of succinic acid, which is a useful compound. Results Constructing the SyHyMeP model enabled new metabolic designs for producing useful compounds. In the present study, we developed a metabolic design that allowed for improved theoretical yield in the production of succinic acid during glycogen metabolism by Synechosystis sp. 6803. The theoretical yield of succinic acid production using a genome-scale model of these cells was 1.00 mol/mol-glucose, but use of the SyHyMeP model enabled a metabolic design with which a 33 % increase in theoretical yield is expected due to the introduction of isocitrate lyase, adding activations of endogenous tree reactions via D-glycerate in Synechosystis sp. 6803. Conclusions The SyHyMeP model developed in this study has provided a new metabolic design that is not restricted only to the metabolic reactions of individual microbial cells. The concept of construction of this model requires only replacement of the genome-scale model of the host microbial cells and can thus be applied to various useful microorganisms for metabolic design to produce compounds. Electronic supplementary material The online version of this article (doi:10.1186/s12934-016-0416-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Tomokazu Shirai
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan.
| | - Takashi Osanai
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan. .,Department of Agricultural Chemistry, School of Agriculture, Meiji University, 1-1-1, Higashimita, Tamaku, Kawasaki, Kanagawa, 214-8571, Japan.
| | - Akihiko Kondo
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan. .,Organization of Advanced Science and Technology, Kobe University, 1-1 Rokkodaicho, Nada, Kobe, 657-8501, Japan. .,Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodaicho, Nada, Kobe, 657-8501, Japan.
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Verseux CN, Paulino-Lima IG, Baqué M, Billi D, Rothschild LJ. Synthetic Biology for Space Exploration: Promises and Societal Implications. ETHICS OF SCIENCE AND TECHNOLOGY ASSESSMENT 2016. [DOI: 10.1007/978-3-319-21088-9_4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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50
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Osanai T, Iijima H, Hirai MY. Understanding Sugar Catabolism in Unicellular Cyanobacteria Toward the Application in Biofuel and Biomaterial Production. Subcell Biochem 2016; 86:511-523. [PMID: 27023248 DOI: 10.1007/978-3-319-25979-6_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Synechocystis sp. PCC 6803 is a model species of the cyanobacteria that undergo oxygenic photosynthesis, and has garnered much attention for its potential biotechnological applications. The regulatory mechanism of sugar metabolism in this cyanobacterium has been intensively studied and recent omics approaches have revealed the changes in transcripts, proteins, and metabolites of sugar catabolism under different light and nutrient conditions. Several transcriptional regulators that control the gene expression of enzymes related to sugar catabolism have been identified in the past 10 years, including a sigma factor, transcription factors, and histidine kinases. The modification of these genes can lead to alterations in the primary metabolism as well as the levels of high-value products such as bioplastics and hydrogen. This review summarizes recent studies on sugar catabolism in Synechocystis sp. PCC 6803, emphasizing the importance of elucidating the molecular mechanisms of cyanobacterial metabolism for biotechnological applications.
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Affiliation(s)
- Takashi Osanai
- School of Agriculture, Meiji University, 1-1-1, Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan.
| | - Hiroko Iijima
- School of Agriculture, Meiji University, 1-1-1, Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan
| | - Masami Yokota Hirai
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
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