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Flores L, Shene C. Single Amino Acids as Sole Nitrogen Source for the Production of Lipids and Coenzyme Q by Thraustochytrium sp. RT2316-16. Microorganisms 2024; 12:1428. [PMID: 39065196 PMCID: PMC11279195 DOI: 10.3390/microorganisms12071428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2024] [Revised: 07/08/2024] [Accepted: 07/11/2024] [Indexed: 07/28/2024] Open
Abstract
This work analyzes the production of total lipids and the content of CoQ9 and CoQ10 in the biomass of Thraustochytrium sp. RT2316-16 grown in media containing a single amino acid at a concentration of 1 g L-1 as the sole nitrogen source; glucose (5 g L-1) was used as the carbon source. Biomass concentration and the content of total lipids and CoQ were determined as a function of the incubation time; ten amino acids were evaluated. The final concentration of the total biomass was found to be between 2.2 ± 0.1 (aspartate) and 3.9 ± 0.1 g L-1 (glutamate). The biomass grown in media containing glutamate, serine or phenylalanine reached a content of total lipids higher than 20% of the cell dry weight (DW) after 72, 60 and 72 h of incubation, respectively. The highest contents of CoQ9 (39.0 ± 0.7 µg g-1 DW) and CoQ10 (167.4 ± 3.4 mg g-1 DW) in the biomass of the thraustochytrid were obtained when glutamate and cysteine were used as the nitrogen source, respectively. Fatty acid oxidation, which decreased the total lipid content during the first 12 h of incubation, and the oxidation of hydrogen sulfide when cysteine was the nitrogen source, might be related to the content of CoQ10 in the biomass of the thraustochytrid.
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Affiliation(s)
| | - Carolina Shene
- Department of Chemical Engineering, Center of Food Biotechnology and Bioseparations, BIOREN, and Centre of Biotechnology and Bioengineering (CeBiB), Universidad de La Frontera, Temuco 4780000, Chile;
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Flores L, Shene C, Asenjo JA, Chisti Y. Coenzyme Q in Thraustochytrium sp. RT2316-16: Effect of the Medium Composition. Mar Drugs 2023; 21:586. [PMID: 37999410 PMCID: PMC10672569 DOI: 10.3390/md21110586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 11/05/2023] [Accepted: 11/07/2023] [Indexed: 11/25/2023] Open
Abstract
Coenzyme Q (CoQ; ubiquinone) is an essential component of the respiratory chain. It is also a potent antioxidant that prevents oxidative damage to DNA, biological membranes, and lipoproteins. CoQ comprises a six-carbon ring with polar substituents that interact with electron acceptors and donors, and a hydrophobic polyisoprenoid chain that allows for its localization in cellular membranes. Human CoQ has 10 isoprenoid units (CoQ10) within the polyisoprenoid chain. Few microorganisms produce CoQ10. This work shows that Thraustochytrium sp. RT2316-16 produces CoQ10 and CoQ9. The CoQ10 content in RT2316-16 depended strongly on the composition of the growth medium and the age of the culture, whereas the CoQ9 content was less variable probably because it served a different function in the cell. Adding p-hydroxybenzoic acid to the culture media positively influenced the CoQ10 content of the cell. The absence of some B vitamins and p-aminobenzoic acid in the culture medium negatively affected the growth of RT2316-16, but reduced the decline in CoQ10 that otherwise occurred during growth. The highest content of CoQ9 and CoQ10 in the biomass were 855 μg g-1 and 10 mg g-1, respectively. The results presented here suggest that the thraustochytrid RT2316-16 can be a potential vehicle for producing CoQ10. Metabolic signals that trigger the synthesis of CoQ10 in RT2316-16 need to be determined for optimizing culture conditions.
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Affiliation(s)
- Liset Flores
- Department of Chemical Engineering, Center of Food Biotechnology and Bioseparations, BIOREN, and Centre of Biotechnology and Bioengineering (CeBiB), Universidad de La Frontera, Temuco 4811230, Chile;
| | - Carolina Shene
- Department of Chemical Engineering, Center of Food Biotechnology and Bioseparations, BIOREN, and Centre of Biotechnology and Bioengineering (CeBiB), Universidad de La Frontera, Temuco 4811230, Chile;
| | - Juan A. Asenjo
- Centre for Biotechnoloy and Bioengineering (CeBiB), Department of Chemical Engineering, Biotechnology and Materials, Universidad de Chile, Beauchef 851, Santiago 8370459, Chile;
| | - Yusuf Chisti
- Institute of Tropical Aquaculture and Fisheries, Universiti Malaysia Terengganu, Kuala Nerus 21030, Terengganu, Malaysia;
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3
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Accurate and online quantification of viable Rhodobacter sphaeroides cells using a flow cytometry-dielectric spectroscopy (FCM-DS) method. Talanta 2022; 245:123448. [DOI: 10.1016/j.talanta.2022.123448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 03/27/2022] [Accepted: 04/02/2022] [Indexed: 11/23/2022]
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Pierrel F, Burgardt A, Lee JH, Pelosi L, Wendisch VF. Recent advances in the metabolic pathways and microbial production of coenzyme Q. World J Microbiol Biotechnol 2022; 38:58. [PMID: 35178585 PMCID: PMC8854274 DOI: 10.1007/s11274-022-03242-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 01/30/2022] [Indexed: 12/13/2022]
Abstract
Coenzyme Q (CoQ) serves as an electron carrier in aerobic respiration and has become an interesting target for biotechnological production due to its antioxidative effect and benefits in supplementation to patients with various diseases. Here, we review discovery of the pathway with a particular focus on its superstructuration and regulation, and we summarize the metabolic engineering strategies for overproduction of CoQ by microorganisms. Studies in model microorganisms elucidated the details of CoQ biosynthesis and revealed the existence of multiprotein complexes composed of several enzymes that catalyze consecutive reactions in the CoQ pathways of Saccharomyces cerevisiae and Escherichia coli. Recent findings indicate that the identity and the total number of proteins involved in CoQ biosynthesis vary between species, which raises interesting questions about the evolution of the pathway and could provide opportunities for easier engineering of CoQ production. For the biotechnological production, so far only microorganisms have been used that naturally synthesize CoQ10 or a related CoQ species. CoQ biosynthesis requires the aromatic precursor 4-hydroxybenzoic acid and the prenyl side chain that defines the CoQ species. Up to now, metabolic engineering strategies concentrated on the overproduction of the prenyl side chain as well as fine-tuning the expression of ubi genes from the ubiquinone modification pathway, resulting in high CoQ yields. With expanding knowledge about CoQ biosynthesis and exploration of new strategies for strain engineering, microbial CoQ production is expected to improve.
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Affiliation(s)
- Fabien Pierrel
- Univ. Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, 38000, Grenoble, France.
| | - Arthur Burgardt
- Genetics of Prokaryotes, Faculty of Biology and Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Jin-Ho Lee
- Department of Food Science & Biotechnology, Kyungsung University, Busan, South Korea
| | - Ludovic Pelosi
- Univ. Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, 38000, Grenoble, France
| | - Volker F Wendisch
- Genetics of Prokaryotes, Faculty of Biology and Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany.
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5
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Enhanced production and characterization of coenzyme Q10 from Rhodobacter sphaeroides using a potential fermentation strategy. J Taiwan Inst Chem Eng 2022. [DOI: 10.1016/j.jtice.2021.104201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Burgardt A, Moustafa A, Persicke M, Sproß J, Patschkowski T, Risse JM, Peters-Wendisch P, Lee JH, Wendisch VF. Coenzyme Q 10 Biosynthesis Established in the Non-Ubiquinone Containing Corynebacterium glutamicum by Metabolic Engineering. Front Bioeng Biotechnol 2021; 9:650961. [PMID: 33859981 PMCID: PMC8042324 DOI: 10.3389/fbioe.2021.650961] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 02/22/2021] [Indexed: 11/13/2022] Open
Abstract
Coenzyme Q10 (CoQ10) serves as an electron carrier in aerobic respiration and has become an interesting target for biotechnological production due to its antioxidative effect and benefits in supplementation to patients with various diseases. For the microbial production, so far only bacteria have been used that naturally synthesize CoQ10 or a related CoQ species. Since the whole pathway involves many enzymatic steps and has not been fully elucidated yet, the set of genes required for transfer of CoQ10 synthesis to a bacterium not naturally synthesizing CoQ species remained unknown. Here, we established CoQ10 biosynthesis in the non-ubiquinone-containing Gram-positive Corynebacterium glutamicum by metabolic engineering. CoQ10 biosynthesis involves prenylation and, thus, requires farnesyl diphosphate as precursor. A carotenoid-deficient strain was engineered to synthesize an increased supply of the precursor molecule farnesyl diphosphate. Increased farnesyl diphosphate supply was demonstrated indirectly by increased conversion to amorpha-4,11-diene. To provide the first CoQ10 precursor decaprenyl diphosphate (DPP) from farnesyl diphosphate, DPP synthase gene ddsA from Paracoccus denitrificans was expressed. Improved supply of the second CoQ10 precursor, para-hydroxybenzoate (pHBA), resulted from metabolic engineering of the shikimate pathway. Prenylation of pHBA with DPP and subsequent decarboxylation, hydroxylation, and methylation reactions to yield CoQ10 was achieved by expression of ubi genes from Escherichia coli. CoQ10 biosynthesis was demonstrated in shake-flask cultivation and verified by liquid chromatography mass spectrometry analysis. To the best of our knowledge, this is the first report of CoQ10 production in a non-ubiquinone-containing bacterium.
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Affiliation(s)
- Arthur Burgardt
- Genetics of Prokaryotes, Faculty of Biology and Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Ayham Moustafa
- Genetics of Prokaryotes, Faculty of Biology and Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Marcus Persicke
- Technology Platform Genomics, Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Jens Sproß
- Industrial Organic Chemistry and Biotechnology, Department of Chemistry, Bielefeld University, Bielefeld, Germany
| | - Thomas Patschkowski
- Technology Platform Genomics, Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Joe Max Risse
- Fermentation Technology, Technical Faculty and Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Petra Peters-Wendisch
- Genetics of Prokaryotes, Faculty of Biology and Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Jin-Ho Lee
- Major in Food Science & Biotechnology, School of Food Biotechnology & Nutrition, Kyungsung University, Busan, South Korea
| | - Volker F Wendisch
- Genetics of Prokaryotes, Faculty of Biology and Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
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Liu Y, Gao J, Bai Z, Wu S, Li X, Wang N, Du X, Fan H, Zhuang G, Bohu T, Zhuang X. Unraveling Mechanisms and Impact of Microbial Recruitment on Oilseed Rape ( Brassica napus L.) and the Rhizosphere Mediated by Plant Growth-Promoting Rhizobacteria. Microorganisms 2021; 9:microorganisms9010161. [PMID: 33445684 PMCID: PMC7828142 DOI: 10.3390/microorganisms9010161] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 12/31/2020] [Accepted: 01/06/2021] [Indexed: 01/13/2023] Open
Abstract
Plant growth-promoting rhizobacteria (PGPR) are noticeably applied to enhance plant nutrient acquisition and improve plant growth and health. However, limited information is available on the compositional dynamics of rhizobacteria communities with PGPR inoculation. In this study, we investigated the effects of three PGPR strains, Stenotrophomonas rhizophila, Rhodobacter sphaeroides, and Bacillus amyloliquefaciens on the ecophysiological properties of Oilseed rape (Brassica napus L.), rhizosphere, and bulk soil; moreover, we assessed rhizobacterial community composition using high-throughput Illumina sequencing of 16S rRNA genes. Inoculation with S. rhizophila, R. sphaeroides, and B. amyloliquefaciens, significantly increased the plant total N (TN) (p < 0.01) content. R. sphaeroides and B. amyloliquefaciens selectively enhanced the growth of Pseudomonadacea and Flavobacteriaceae, whereas S. rhizophila could recruit diazotrophic rhizobacteria, members of Cyanobacteria and Actinobacteria, whose abundance was positively correlated with inoculation, and improved the transformation of organic nitrogen into inorganic nitrogen through the promotion of ammonification. Initial colonization by PGPR in the rhizosphere affected the rhizobacterial community composition throughout the plant life cycle. Network analysis indicated that PGPR had species-dependent effects on niche competition in the rhizosphere. These results provide a better understanding of PGPR-plant-rhizobacteria interactions, which is necessary to develop the application of PGPR.
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Affiliation(s)
- Ying Liu
- School of Life Sciences, University of Science and Technology of China, Hefei 230026, China;
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; (J.G.); (Z.B.); (S.W.); (X.L.); (N.W.); (X.D.); (H.F.); (G.Z.)
| | - Jie Gao
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; (J.G.); (Z.B.); (S.W.); (X.L.); (N.W.); (X.D.); (H.F.); (G.Z.)
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhihui Bai
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; (J.G.); (Z.B.); (S.W.); (X.L.); (N.W.); (X.D.); (H.F.); (G.Z.)
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shanghua Wu
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; (J.G.); (Z.B.); (S.W.); (X.L.); (N.W.); (X.D.); (H.F.); (G.Z.)
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xianglong Li
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; (J.G.); (Z.B.); (S.W.); (X.L.); (N.W.); (X.D.); (H.F.); (G.Z.)
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Na Wang
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; (J.G.); (Z.B.); (S.W.); (X.L.); (N.W.); (X.D.); (H.F.); (G.Z.)
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiongfeng Du
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; (J.G.); (Z.B.); (S.W.); (X.L.); (N.W.); (X.D.); (H.F.); (G.Z.)
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Haonan Fan
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; (J.G.); (Z.B.); (S.W.); (X.L.); (N.W.); (X.D.); (H.F.); (G.Z.)
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guoqiang Zhuang
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; (J.G.); (Z.B.); (S.W.); (X.L.); (N.W.); (X.D.); (H.F.); (G.Z.)
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tsing Bohu
- CSIRO Mineral Resources, Kensington, WA 6151, Australia;
| | - Xuliang Zhuang
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; (J.G.); (Z.B.); (S.W.); (X.L.); (N.W.); (X.D.); (H.F.); (G.Z.)
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: ; Tel.: +86-10-6284-9193
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8
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Oxygen Uptake Rate Controlling Strategy Balanced with Oxygen Supply for Improving Coenzyme Q10 Production by Rhodobacter sphaeroides. BIOTECHNOL BIOPROC E 2020. [DOI: 10.1007/s12257-019-0461-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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9
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Capson-Tojo G, Batstone DJ, Grassino M, Vlaeminck SE, Puyol D, Verstraete W, Kleerebezem R, Oehmen A, Ghimire A, Pikaar I, Lema JM, Hülsen T. Purple phototrophic bacteria for resource recovery: Challenges and opportunities. Biotechnol Adv 2020; 43:107567. [PMID: 32470594 DOI: 10.1016/j.biotechadv.2020.107567] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 05/11/2020] [Accepted: 05/14/2020] [Indexed: 10/24/2022]
Abstract
Sustainable development is driving a rapid focus shift in the wastewater and organic waste treatment sectors, from a "removal and disposal" approach towards the recovery and reuse of water, energy and materials (e.g. carbon or nutrients). Purple phototrophic bacteria (PPB) are receiving increasing attention due to their capability of growing photoheterotrophically under anaerobic conditions. Using light as energy source, PPB can simultaneously assimilate carbon and nutrients at high efficiencies (with biomass yields close to unity (1 g CODbiomass·g CODremoved-1)), facilitating the maximum recovery of these resources as different value-added products. The effective use of infrared light enables selective PPB enrichment in non-sterile conditions, without competition with other phototrophs such as microalgae if ultraviolet-visible wavelengths are filtered. This review reunites results systematically gathered from over 177 scientific articles, aiming at producing generalized conclusions. The most critical aspects of PPB-based production and valorisation processes are addressed, including: (i) the identification of the main challenges and potentials of different growth strategies, (ii) a critical analysis of the production of value-added compounds, (iii) a comparison of the different value-added products, (iv) insights into the general challenges and opportunities and (v) recommendations for future research and development towards practical implementation. To date, most of the work has not been executed under real-life conditions, relevant for full-scale application. With the savings in wastewater discharge due to removal of organics, nitrogen and phosphorus as an important economic driver, priorities must go to using PPB-enriched cultures and real waste matrices. The costs associated with artificial illumination, followed by centrifugal harvesting/dewatering and drying, are estimated to be 1.9, 0.3-2.2 and 0.1-0.3 $·kgdry biomass-1. At present, these costs are likely to exceed revenues. Future research efforts must be carried out outdoors, using sunlight as energy source. The growth of bulk biomass on relatively clean wastewater streams (e.g. from food processing) and its utilization as a protein-rich feed (e.g. to replace fishmeal, 1.5-2.0 $·kg-1) appears as a promising valorisation route.
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Affiliation(s)
- Gabriel Capson-Tojo
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD 4072, Australia; CRETUS Institute, Department of Chemical Engineering, School of Engineering, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
| | - Damien J Batstone
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - María Grassino
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Siegfried E Vlaeminck
- Research Group of Sustainable Energy, Air and Water Technology, Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium.
| | - Daniel Puyol
- Department of Chemical and Environmental Technology, ESCET, Rey Juan Carlos University, Móstoles, Spain.
| | - Willy Verstraete
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Gent, Belgium; Avecom NV, Industrieweg 122P, 9032 Wondelgem, Belgium.
| | - Robbert Kleerebezem
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, the Netherlands.
| | - Adrian Oehmen
- School of Chemical Engineering, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Anish Ghimire
- Department of Environmental Science and Engineering, Kathmandu University, Dhulikhel, Nepal.
| | - Ilje Pikaar
- School of Civil Engineering, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Juan M Lema
- CRETUS Institute, Department of Chemical Engineering, School of Engineering, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
| | - Tim Hülsen
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD 4072, Australia.
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Xu M, Wu H, Shen P, Jiang X, Chen X, Lin J, Huang J, Qi F. Enhancement of NADPH availability for coproduction of coenzyme Q 10 and farnesol from Rhodobacter sphaeroides. J Ind Microbiol Biotechnol 2020; 47:263-274. [PMID: 31993848 DOI: 10.1007/s10295-020-02261-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Accepted: 01/14/2020] [Indexed: 12/16/2022]
Abstract
Coenzyme Q10 (CoQ10)-an essential cofactor in the respiratory electron transport chain-has important pharmaceutical and healthcare applications. Farnesol (FOH)-an acyclic sesquiterpene alcohol-has garnered interest owing to its valuable clinical and medical benefits. Here, the coproduction of CoQ10 and FOH in Rhodobacter sphaeroides GY-2 was greatly improved through the enhancement of intracellular NADPH availability. Transcription of pgi, gdhA, and nuocd was, respectively, inhibited using RNA interference to reduce intracellular NAD(P)H consumption. Moreover, zwf, gnd, and zwf + gnd were overexpressed to enhance the pentose phosphate pathway, resulting in improved NADPH availability in most metabolically engineered R. sphaeroides strains. RSg-pgi with RNAi of pgi combined with overexpression of gnd produced 55.05 mg/L FOH that is twofold higher than the parental strain GY-2, and 185.5 mg/L CoQ10 can be coproduced at the same time. In conclusion, improved carbon flux can be redirected toward NADPH-dependent biosynthesis through the enhancement of NADPH availability.
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Affiliation(s)
- Man Xu
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China
| | - Hongxuan Wu
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China
| | - Peijie Shen
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China
| | - Xianzhang Jiang
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China.
| | - Xueduan Chen
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China
| | - Jinxin Lin
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China
| | - Jianzhong Huang
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China.
| | - Feng Qi
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China.
- Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation and Provincial University Engineering Research Center of Industrial Biocatalysis, Fujian Normal University, Fuzhou, 350117, Fujian, China.
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11
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Orsi E, Folch PL, Monje-López VT, Fernhout BM, Turcato A, Kengen SWM, Eggink G, Weusthuis RA. Characterization of heterotrophic growth and sesquiterpene production by Rhodobacter sphaeroides on a defined medium. J Ind Microbiol Biotechnol 2019; 46:1179-1190. [PMID: 31187318 PMCID: PMC6697705 DOI: 10.1007/s10295-019-02201-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 05/29/2019] [Indexed: 11/30/2022]
Abstract
Rhodobacter sphaeroides is a metabolically versatile bacterium capable of producing terpenes natively. Surprisingly, terpene biosynthesis in this species has always been investigated in complex media, with unknown compounds possibly acting as carbon and nitrogen sources. Here, a defined medium was adapted for R. sphaeroides dark heterotrophic growth, and was used to investigate the conversion of different organic substrates into the reporter terpene amorphadiene. The amorphadiene synthase was cloned in R. sphaeroides, allowing its biosynthesis via the native 2-methyl-d-erythritol-4-phosphate (MEP) pathway and, additionally, via a heterologous mevalonate one. The latter condition increased titers up to eightfold. Consequently, better yields and productivities to previously reported complex media cultivations were achieved. Productivity was further investigated under different cultivation conditions, including nitrogen and oxygen availability. This novel cultivation setup provided useful insight into the understanding of terpene biosynthesis in R. sphaeroides, allowing to better comprehend its dynamics and regulation during chemoheterotrophic cultivation.
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Affiliation(s)
- Enrico Orsi
- Bioprocess Engineering, Department of Agrotechnology and Food, Wageningen University and Research, Wageningen, The Netherlands
| | - Pauline L Folch
- Bioprocess Engineering, Department of Agrotechnology and Food, Wageningen University and Research, Wageningen, The Netherlands
| | - Vicente T Monje-López
- Bioprocess Engineering, Department of Agrotechnology and Food, Wageningen University and Research, Wageningen, The Netherlands
| | - Bas M Fernhout
- Bioprocess Engineering, Department of Agrotechnology and Food, Wageningen University and Research, Wageningen, The Netherlands
| | - Alessandro Turcato
- Bioprocess Engineering, Department of Agrotechnology and Food, Wageningen University and Research, Wageningen, The Netherlands
| | - Servé W M Kengen
- Laboratory of Microbiology, Department of Agrotechnology and Food, Wageningen University and Research, Wageningen, The Netherlands
| | - Gerrit Eggink
- Bioprocess Engineering, Department of Agrotechnology and Food, Wageningen University and Research, Wageningen, The Netherlands.,Biobased Products Food and Biobased Research, Wageningen University and Research, Wageningen, The Netherlands
| | - Ruud A Weusthuis
- Bioprocess Engineering, Department of Agrotechnology and Food, Wageningen University and Research, Wageningen, The Netherlands.
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12
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Chen X, Jiang X, Xu M, Zhang M, Huang R, Huang J, Qi F. Co-production of farnesol and coenzyme Q 10 from metabolically engineered Rhodobacter sphaeroides. Microb Cell Fact 2019; 18:98. [PMID: 31151455 PMCID: PMC6544981 DOI: 10.1186/s12934-019-1145-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 05/20/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Farnesol is an acyclic sesquiterpene alcohol present in the essential oils of various plants in nature. It has been reported to be valuable in medical applications, such as alleviation of allergic asthma, gliosis, and edema as well as anti-cancerous and anti-inflammatory effects. Coenzyme Q10 (CoQ10), an essential cofactor in the aerobic respiratory electron transport chain, has attracted growing interest owing to its clinical benefits and important applications in the pharmaceutical, food, and health industries. In this work, co-production of (E,E)-farnesol (FOH) and CoQ10 was achieved by combining 3 different exogenous terpenes or sesquiterpene synthase with the RNA interference of psy (responsible for phytoene synthesis in Rhodobacter sphaeroides GY-2). RESULTS FOH production was significantly increased by overexpressing exogenous terpene synthase (TPS), phosphatidylglycerophosphatase B (PgpB), and sesquiterpene synthase (ATPS), as well as RNAi-mediated silencing of psy coding phytoene synthase (PSY) in R. sphaeroides strains. Rs-TPS, Rs-ATPS, and Rs-PgpB respectively produced 68.2%, 43.4%, and 21.9% higher FOH titers than that of the control strain. Interestingly, the CoQ10 production of these 3 recombinant R. sphaeroides strains was exactly opposite to that of FOH. However, CoQ10 production was almost unaffected in R. sphaeroides strains modified by psy RNA interference. The highest FOH production of 40.45 mg/L, which was twice as high as that of the control, was obtained from the TPS-PSYi strain, where the exogenous TPS was combined with the weakening of the phytoene synthesis pathway via psy RNA interference. CoQ10 production in TPS-PSYi, ATPS-PSYi, and PgpB-PSYi was decreased and lower than that of the control strain. CONCLUSIONS The original flux that contributed to phytoene synthesis was effectively redirected to provide precursors toward FOH or CoQ10 synthesis via psy RNA interference, which led to weakened carotenoid synthesis. The improved flux that was originally involved in CoQ10 production and phytoene synthesis was redirected toward FOH synthesis via metabolic modification. This is the first reported instance of FOH and CoQ10 co-production in R. sphaeroides using a metabolic engineering strategy.
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Affiliation(s)
- Xueduan Chen
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China
| | - Xianzhang Jiang
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China
| | - Man Xu
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China
| | - Mingliang Zhang
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China
| | - Runye Huang
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China
| | - Jianzhong Huang
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China.
| | - Feng Qi
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China. .,Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation & Fujian Provincial University Engineering Research Center of Industrial Biocatalysis, Fujian Normal University, Fuzhou, 350117, Fujian, China.
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Whole-genome sequence of purple non-sulfur bacteria, Rhodobacter sphaeroides strain MBTLJ-8 with improved CO2 reduction capacity. J Biotechnol 2018; 288:9-14. [DOI: 10.1016/j.jbiotec.2018.10.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 10/19/2018] [Accepted: 10/20/2018] [Indexed: 01/13/2023]
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14
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Benchmark study of photosynthetic bacteria bio-conversion of wastewater: Carbon source range, fundamental kinetics of substrate degradation and cell proliferation. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/j.biteb.2018.02.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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15
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Li L, Ding F, Sang L, Liu J, Mao D, Liu X, Xu Q. Study on the oxygen reduction reaction catalyzed by a cold-tolerant marine strain phylogenetically related to Erythrobacter citreus. Bioelectrochemistry 2017; 119:51-58. [PMID: 28915379 DOI: 10.1016/j.bioelechem.2017.08.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Revised: 08/18/2017] [Accepted: 08/24/2017] [Indexed: 02/05/2023]
Abstract
As the development of marine economy, the submarine battery with the seawater electrolyte has obtained more and more attentions. Owing to the conventional electrochemical catalysts of the cathodes in seawater battery are expensive, it is to seek the new biological catalysts to improve the electrochemical performance of the cathode and reduce the cost of seawater battery. A novel marine bacterial strain (Strain SQ-32) phylogenetically related to the Erythrobactercitreus strain has been isolated from the sea-bed sludge in the Yellow Sea of China successfully. The electrochemical measurements, which include the cyclic voltammetry, potentiostatic polarization, and electrochemical impedance spectroscopy, have been conducted in synthetic seawater. The electrochemical testing results show that the Strain SQ-32 is a cold-tolerant bacterium, which may exhibit a catalytic activity for the ORR in synthetic seawater at a freezing temperature. The SEM photo demonstrates that the Strain SQ-32 displays a rod-shaped characteristic, which has a diameter of 0.4μm and a length of about 1-2.5μm. By the testing of Gram staining, the Strain SQ-32 has been identified as a Gram-negative bacterium. The chemical analytical result reveals that the bacterium cell of Strain SQ-32 contains 1.92mgg-1 (DCW) of coenzyme Q10, which is a possible impact factor on the electro-catalytic effect on the Strain SQ-32. The exploitation of Strain SQ-32 may boost the development of the biocathode of seawater battery at a low temperature.
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Affiliation(s)
- Lianqiang Li
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China; National Key Laboratory of Science and Technology on Power Sources, Tianjin Institute of Power Sources, Tianjin 300384, PR China
| | - Fei Ding
- National Key Laboratory of Science and Technology on Power Sources, Tianjin Institute of Power Sources, Tianjin 300384, PR China.
| | - Lin Sang
- National Key Laboratory of Science and Technology on Power Sources, Tianjin Institute of Power Sources, Tianjin 300384, PR China
| | - Jiaquan Liu
- School of Engineering and Applied Science, George Washington University, Washington DC 20052, USA
| | - Duolu Mao
- School of Physical and Electronic Information Engineering, Qinghai Nationalities University, Qinghai 810007, PR China
| | - Xingjiang Liu
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China; National Key Laboratory of Science and Technology on Power Sources, Tianjin Institute of Power Sources, Tianjin 300384, PR China
| | - Qiang Xu
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China.
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Combining Genome-Scale Experimental and Computational Methods To Identify Essential Genes in Rhodobacter sphaeroides. mSystems 2017; 2:mSystems00015-17. [PMID: 28744485 PMCID: PMC5513736 DOI: 10.1128/msystems.00015-17] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 05/16/2017] [Indexed: 12/14/2022] Open
Abstract
Knowledge about the role of genes under a particular growth condition is required for a holistic understanding of a bacterial cell and has implications for health, agriculture, and biotechnology. We developed the Tn-seq analysis software (TSAS) package to provide a flexible and statistically rigorous workflow for the high-throughput analysis of insertion mutant libraries, advanced the knowledge of gene essentiality in R. sphaeroides, and illustrated how Tn-seq data can be used to more accurately identify genes that play important roles in metabolism and other processes that are essential for cellular survival. Rhodobacter sphaeroides is one of the best-studied alphaproteobacteria from biochemical, genetic, and genomic perspectives. To gain a better systems-level understanding of this organism, we generated a large transposon mutant library and used transposon sequencing (Tn-seq) to identify genes that are essential under several growth conditions. Using newly developed Tn-seq analysis software (TSAS), we identified 493 genes as essential for aerobic growth on a rich medium. We then used the mutant library to identify conditionally essential genes under two laboratory growth conditions, identifying 85 additional genes required for aerobic growth in a minimal medium and 31 additional genes required for photosynthetic growth. In all instances, our analyses confirmed essentiality for many known genes and identified genes not previously considered to be essential. We used the resulting Tn-seq data to refine and improve a genome-scale metabolic network model (GEM) for R. sphaeroides. Together, we demonstrate how genetic, genomic, and computational approaches can be combined to obtain a systems-level understanding of the genetic framework underlying metabolic diversity in bacterial species. IMPORTANCE Knowledge about the role of genes under a particular growth condition is required for a holistic understanding of a bacterial cell and has implications for health, agriculture, and biotechnology. We developed the Tn-seq analysis software (TSAS) package to provide a flexible and statistically rigorous workflow for the high-throughput analysis of insertion mutant libraries, advanced the knowledge of gene essentiality in R. sphaeroides, and illustrated how Tn-seq data can be used to more accurately identify genes that play important roles in metabolism and other processes that are essential for cellular survival. Author Video: An author video summary of this article is available.
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Abstract
Lipids from microbes offer a promising source of renewable alternatives to petroleum-derived compounds. In particular, oleaginous microbes are of interest because they accumulate a large fraction of their biomass as lipids. In this study, we analyzed genetic changes that alter lipid accumulation in Rhodobacter sphaeroides. By screening an R. sphaeroides Tn5 mutant library for insertions that increased fatty acid content, we identified 10 high-lipid (HL) mutants for further characterization. These HL mutants exhibited increased sensitivity to drugs that target the bacterial cell envelope and changes in shape, and some had the ability to secrete lipids, with two HL mutants accumulating ~60% of their total lipids extracellularly. When one of the highest-lipid-secreting strains was grown in a fed-batch bioreactor, its lipid content was comparable to that of oleaginous microbes, with the majority of the lipids secreted into the medium. Based on the properties of these HL mutants, we conclude that alterations of the cell envelope are a previously unreported approach to increase microbial lipid production. We also propose that this approach may be combined with knowledge about biosynthetic pathways, in this or other microbes, to increase production of lipids and other chemicals. This paper reports on experiments to understand how to increase microbial lipid production. Microbial lipids are often cited as one renewable replacement for petroleum-based fuels and chemicals, but strategies to increase the yield of these compounds are needed to achieve this goal. While lipid biosynthesis is often well understood, increasing yields of these compounds to industrially relevant levels is a challenge, especially since genetic, synthetic biology, or engineering approaches are not feasible in many microbes. We show that altering the bacterial cell envelope can be used to increase microbial lipid production. We also find that the utility of some of these alterations can be enhanced by growing cells in bioreactor configurations that can be used industrially. We propose that our findings can inform current and future efforts to increase production of microbial lipids, other fuels, or chemicals that are currently derived from petroleum.
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18
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Lee SQE, Tan TS, Kawamukai M, Chen ES. Cellular factories for coenzyme Q 10 production. Microb Cell Fact 2017; 16:39. [PMID: 28253886 PMCID: PMC5335738 DOI: 10.1186/s12934-017-0646-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 02/10/2017] [Indexed: 04/20/2023] Open
Abstract
Coenzyme Q10 (CoQ10), a benzoquinone present in most organisms, plays an important role in the electron-transport chain, and its deficiency is associated with various neuropathies and muscular disorders. CoQ10 is the only lipid-soluble antioxidant found in humans, and for this, it is gaining popularity in the cosmetic and healthcare industries. To meet the growing demand for CoQ10, there has been considerable interest in ways to enhance its production, the most effective of which remains microbial fermentation. Previous attempts to increase CoQ10 production to an industrial scale have thus far conformed to the strategies used in typical metabolic engineering endeavors. However, the emergence of new tools in the expanding field of synthetic biology has provided a suite of possibilities that extend beyond the traditional modes of metabolic engineering. In this review, we cover the various strategies currently undertaken to upscale CoQ10 production, and discuss some of the potential novel areas for future research.
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Affiliation(s)
- Sean Qiu En Lee
- Department of Biochemistry, National University of Singapore, Singapore, Singapore
| | - Tsu Soo Tan
- School of Chemical & Life Sciences, Nanyang Polytechnic, Singapore, Singapore
| | - Makoto Kawamukai
- Faculty of Life and Environmental Science, Shimane University, Matsue, 690-8504, Japan
| | - Ee Sin Chen
- Department of Biochemistry, National University of Singapore, Singapore, Singapore. .,National University Health System (NUHS), Singapore, Singapore. .,NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), Life Sciences Institute, National University of Singapore, Singapore, Singapore. .,NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore, Singapore.
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19
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Qi F, Zou L, Jiang X, Cai S, Zhang M, Zhao X, Huang J. Integration of heterologous 4-hydroxybenzoic acid transport proteins in Rhodobacter sphaeroides for enhancement of coenzyme Q10production. RSC Adv 2017. [DOI: 10.1039/c7ra02346d] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
This work provides a novel genetic engineering strategy that improves uptake of extracellular 4-hydroxybenzoic acid by heterologously expressing the membrane transport protein PcaK inR. sphaeroidesfor enhancement of CoQ10production.
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Affiliation(s)
- Feng Qi
- Engineering Research Center of Industrial Microbiology of Ministry of Education
- College of Life Sciences
- Fujian Normal University
- Fuzhou 350117
- China
| | - Limei Zou
- Engineering Research Center of Industrial Microbiology of Ministry of Education
- College of Life Sciences
- Fujian Normal University
- Fuzhou 350117
- China
| | - Xianzhang Jiang
- Engineering Research Center of Industrial Microbiology of Ministry of Education
- College of Life Sciences
- Fujian Normal University
- Fuzhou 350117
- China
| | - Shaoli Cai
- Biomedical Research Center of South China
- Fujian Normal University
- Fuzhou 350117
- China
| | - Mingliang Zhang
- Engineering Research Center of Industrial Microbiology of Ministry of Education
- College of Life Sciences
- Fujian Normal University
- Fuzhou 350117
- China
| | - Xuebing Zhao
- Institute of Applied Chemistry
- Department of Chemical Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Jianzhong Huang
- Engineering Research Center of Industrial Microbiology of Ministry of Education
- College of Life Sciences
- Fujian Normal University
- Fuzhou 350117
- China
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20
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Liu S, Zhang G, Zhang J, Li X, Li J. Performance, 5-aminolevulinic acid (ALA) yield and microbial population dynamics in a photobioreactor system treating soybean wastewater: Effect of hydraulic retention time (HRT) and organic loading rate (OLR). BIORESOURCE TECHNOLOGY 2016; 210:146-52. [PMID: 26818577 DOI: 10.1016/j.biortech.2016.01.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Revised: 01/11/2016] [Accepted: 01/13/2016] [Indexed: 06/05/2023]
Abstract
Effects of hydraulic retention time (HRT) and influent organic loading rate (OLR) were investigated in a photobioreactor containing PNSB (Rhodobacter sphaeroides)-chemoheterotrophic bacteria to treat soybean wastewater. Pollutants removal, biomass production and ALA yield in different phases were investigated in together with functional microbial population dynamics. The results showed that proper HRT and OLR increased the photobioreactor performance including pollutants removal, biomass and ALA productions. 89.5% COD, 90.6% TN and 91.2% TP removals were achieved as well as the highest biomass production of 2655mg/L and ALA yield of 7.40mg/g-biomass under the optimal HRT of 60h and OLR of 2.48g/L/d. In addition, HRT and OLR have important impacts on PNSB and total bacteria dynamics.
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Affiliation(s)
- Shuli Liu
- School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China
| | - Guangming Zhang
- School of Environment and Resource, Renmin University of China, Beijing 100872, China; School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
| | - Jie Zhang
- School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China
| | - Xiangkun Li
- School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China
| | - Jianzheng Li
- School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China
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21
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Liu S, Zhang G, Li X, Wu P, Zhang J. Enhancement of Rhodobacter sphaeroides growth and carotenoid production through biostimulation. J Environ Sci (China) 2015; 33:21-28. [PMID: 26141874 DOI: 10.1016/j.jes.2015.01.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Revised: 01/14/2015] [Accepted: 01/15/2015] [Indexed: 06/04/2023]
Abstract
Bacillus thuringiensis/cereus L2 was added as a biostimulant to enhance the biomass accumulation and carotenoid yield of Rhodobacter sphaeroides using wastewater as the culturing medium. Results showed that biostimulation could significantly enhance the R. sphaeroides biomass production and carotenoid yield. The optimal biostimulant proportion was 40 μL (about 6.4×10(5) CFU). Through the use of biostimulation, chemical oxygen demand removal, R. sphaeroides biomass production, carotenoid concentration, and carotenoid yield were improved by 178%, 67%, 214%, and 70%, respectively. Theoretical analysis revealed that there were two possible reasons for such increases. One was that biostimulation enhanced the R. sphaeroides wastewater treatment efficiency. The other was that biostimulation significantly decreased the peroxidase activity in R. sphaeroides. The results showed that the highest peroxidase activity dropped by 87% and the induction ratio of the RSP_3419 gene was 3.1 with the addition of biostimulant. The enhanced carotenoid yield in R. sphaeroides could thus be explained by a decrease in peroxidase activity.
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Affiliation(s)
- Shuli Liu
- School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China..
| | - Guangming Zhang
- School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.; School of Environment and Resource, Renmin University of China, Beijing 100872, China.
| | - Xiangkun Li
- School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China
| | - Pan Wu
- School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China
| | - Jie Zhang
- School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China
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22
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An integrated approach to reconstructing genome-scale transcriptional regulatory networks. PLoS Comput Biol 2015; 11:e1004103. [PMID: 25723545 PMCID: PMC4344238 DOI: 10.1371/journal.pcbi.1004103] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 12/23/2014] [Indexed: 11/24/2022] Open
Abstract
Transcriptional regulatory networks (TRNs) program cells to dynamically alter their gene expression in response to changing internal or environmental conditions. In this study, we develop a novel workflow for generating large-scale TRN models that integrates comparative genomics data, global gene expression analyses, and intrinsic properties of transcription factors (TFs). An assessment of this workflow using benchmark datasets for the well-studied γ-proteobacterium Escherichia coli showed that it outperforms expression-based inference approaches, having a significantly larger area under the precision-recall curve. Further analysis indicated that this integrated workflow captures different aspects of the E. coli TRN than expression-based approaches, potentially making them highly complementary. We leveraged this new workflow and observations to build a large-scale TRN model for the α-Proteobacterium Rhodobacter sphaeroides that comprises 120 gene clusters, 1211 genes (including 93 TFs), 1858 predicted protein-DNA interactions and 76 DNA binding motifs. We found that ~67% of the predicted gene clusters in this TRN are enriched for functions ranging from photosynthesis or central carbon metabolism to environmental stress responses. We also found that members of many of the predicted gene clusters were consistent with prior knowledge in R. sphaeroides and/or other bacteria. Experimental validation of predictions from this R. sphaeroides TRN model showed that high precision and recall was also obtained for TFs involved in photosynthesis (PpsR), carbon metabolism (RSP_0489) and iron homeostasis (RSP_3341). In addition, this integrative approach enabled generation of TRNs with increased information content relative to R. sphaeroides TRN models built via other approaches. We also show how this approach can be used to simultaneously produce TRN models for each related organism used in the comparative genomics analysis. Our results highlight the advantages of integrating comparative genomics of closely related organisms with gene expression data to assemble large-scale TRN models with high-quality predictions. The ever growing amount of genomic data enables the assembly of large-scale network models that can provide important new insights into living systems. However, assembly and validation of such large-scale models can be challenging, since we often lack sufficient information to make accurate predictions. This work describes a new approach for constructing large-scale transcriptional regulatory networks of individual cells. We show that the reconstructed network captures a significantly larger fraction of cellular regulatory processes than networks generated by other existing approaches. We predict this approach, with appropriate refinements, will allow reconstruction of large-scale transcriptional network models for a variety of other organisms. As we work towards modeling the function of cells or complex ecosystems, individually reconstructed network models of signaling, information transfer and metabolism, can be integrated to provide high information predictions and insights not otherwise obtainable.
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Imam S, Fitzgerald CM, Cook EM, Donohue TJ, Noguera DR. Quantifying the effects of light intensity on bioproduction and maintenance energy during photosynthetic growth of Rhodobacter sphaeroides. PHOTOSYNTHESIS RESEARCH 2015; 123:167-182. [PMID: 25428581 DOI: 10.1007/s11120-014-0061-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 11/19/2014] [Indexed: 06/04/2023]
Abstract
Obtaining a better understanding of the physiology and bioenergetics of photosynthetic microbes is an important step toward optimizing these systems for light energy capture or production of valuable commodities. In this work, we analyzed the effect of light intensity on bioproduction, biomass formation, and maintenance energy during photoheterotrophic growth of Rhodobacter sphaeroides. Using data obtained from steady-state bioreactors operated at varying dilution rates and light intensities, we found that irradiance had a significant impact on biomass yield and composition, with significant changes in photopigment, phospholipid, and biopolymer storage contents. We also observed a linear relationship between incident light intensity and H2 production rate between 3 and 10 W m(-2), with saturation observed at 100 W m(-2). The light conversion efficiency to H2 was also higher at lower light intensities. Photosynthetic maintenance energy requirements were also significantly affected by light intensity, with links to differences in biomass composition and the need to maintain redox homeostasis. Inclusion of the measured condition-dependent biomass and maintenance energy parameters and the measured photon uptake rate into a genome-scale metabolic model for R. sphaeroides (iRsp1140) significantly improved its predictive performance. We discuss how our analyses provide new insights into the light-dependent changes in bioenergetic requirements and physiology during photosynthetic growth of R. sphaeroides and potentially other photosynthetic organisms.
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Affiliation(s)
- Saheed Imam
- Program in Cellular and Molecular Biology, University of Wisconsin, Madison, WI, USA
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24
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Imam S, Noguera DR, Donohue TJ. Global analysis of photosynthesis transcriptional regulatory networks. PLoS Genet 2014; 10:e1004837. [PMID: 25503406 PMCID: PMC4263372 DOI: 10.1371/journal.pgen.1004837] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2014] [Accepted: 10/20/2014] [Indexed: 12/18/2022] Open
Abstract
Photosynthesis is a crucial biological process that depends on the interplay of many components. This work analyzed the gene targets for 4 transcription factors: FnrL, PrrA, CrpK and MppG (RSP_2888), which are known or predicted to control photosynthesis in Rhodobacter sphaeroides. Chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) identified 52 operons under direct control of FnrL, illustrating its regulatory role in photosynthesis, iron homeostasis, nitrogen metabolism and regulation of sRNA synthesis. Using global gene expression analysis combined with ChIP-seq, we mapped the regulons of PrrA, CrpK and MppG. PrrA regulates ∼34 operons encoding mainly photosynthesis and electron transport functions, while CrpK, a previously uncharacterized Crp-family protein, regulates genes involved in photosynthesis and maintenance of iron homeostasis. Furthermore, CrpK and FnrL share similar DNA binding determinants, possibly explaining our observation of the ability of CrpK to partially compensate for the growth defects of a ΔFnrL mutant. We show that the Rrf2 family protein, MppG, plays an important role in photopigment biosynthesis, as part of an incoherent feed-forward loop with PrrA. Our results reveal a previously unrealized, high degree of combinatorial regulation of photosynthetic genes and significant cross-talk between their transcriptional regulators, while illustrating previously unidentified links between photosynthesis and the maintenance of iron homeostasis. Photosynthetic organisms are among the most abundant life forms on earth. Their unique ability to harvest solar energy and use it to fix atmospheric carbon dioxide is at the foundation of the global food chain. This paper reports the first comprehensive analysis of networks that control expression of photosynthesis genes using Rhodobacter sphaeroides, a microbe that has been studied for decades as a model of solar energy capture and other aspects of the photosynthetic lifestyle. We find a previously unappreciated complexity in the level of control of photosynthetic genes, while identifying new links between photosynthesis and central processes like iron availability. This organism is an ancestor of modern day plants, so our data can inform studies in other photosynthetic organisms and improve our ability to harness solar energy for food and industrial processes.
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Affiliation(s)
- Saheed Imam
- Program in Cellular and Molecular Biology, University of Wisconsin – Madison, Madison, Wisconsin, United States of America
- Department of Bacteriology, University of Wisconsin – Madison, Wisconsin Energy Institute, Madison, Wisconsin, United States of America
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin – Madison, Madison, Wisconsin, United States of America
| | - Daniel R. Noguera
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin – Madison, Madison, Wisconsin, United States of America
- Department of Civil and Environmental Engineering, University of Wisconsin – Madison, Madison, Wisconsin, United States of America
| | - Timothy J. Donohue
- Department of Bacteriology, University of Wisconsin – Madison, Wisconsin Energy Institute, Madison, Wisconsin, United States of America
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin – Madison, Madison, Wisconsin, United States of America
- * E-mail:
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25
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Characterization of mixed organic compounds extracted from Rhodobacter sphaeroides and applications to enhance the physiological responses of fermenting microorganisms. Mol Cell Toxicol 2014. [DOI: 10.1007/s13273-014-0034-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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26
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de Dieu Ndikubwimana J, Lee BH. Enhanced production techniques, properties and uses of coenzyme Q10. Biotechnol Lett 2014; 36:1917-26. [DOI: 10.1007/s10529-014-1587-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 06/11/2014] [Indexed: 12/22/2022]
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27
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HUANG M, CHEN Y, LIU J. Chromosomal Engineering of Escherichia coli for Efficient Production of Coenzyme Q10. Chin J Chem Eng 2014. [DOI: 10.1016/s1004-9541(14)60082-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Ranadive P, Mehta A, Chavan Y, Marx A, George S. Morphological and Molecular Differentiation of Sporidiobolus johnsonii ATCC 20490 and Its Coenzyme Q10 Overproducing Mutant Strain UF16. Indian J Microbiol 2014; 54:343-57. [PMID: 24891743 DOI: 10.1007/s12088-014-0466-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Accepted: 04/03/2014] [Indexed: 11/24/2022] Open
Abstract
Coenzyme Q10 (CoQ10) is an industrially important molecule having nutraceutical and cosmeceutical applications. CoQ10 is mainly produced by microbial fermentation and the process demands the use of strains with high productivity and yields of CoQ10. During strain improvement program consisting of sequential induced mutagenesis, rational selection and screening process, a mutant strain UF16 was generated from Sporidiobolus johnsonii ATCC 20490 with 2.3-fold improvements in CoQ10 content. EMS and UV rays were used as mutagenic agents for generating UF16 and it was rationally selected based on atorvastatin resistance as well as survival at free radicals exposure. We investigated the genotypic and phenotypic changes in UF16 in order to differentiate it from wild type strain. Morphologically it was distinct due to reduced pigmentation of colony, reduced cell size and significant reduction in mycelial growth forms with abundance of yeast forms. At molecular level, UF16 was differentiated based on PCR fingerprinting method of RAPD as well as large and small-subunit rRNA gene sequences. Rapid molecular technique of RAPD analysis using six primers showed 34 % polymorphic fragments with mean genetic distance of 0.235. The partial sequences of rRNA-gene revealed few mutation sites on nucleotide base pairs. However, the mutations detected on rRNA gene of UF16 were less than 1 % of total base pairs and its sequence showed 99 % homology with the wild type strain. These mutations in UF16 could not be linked to phenotypic or genotypic changes on CoQ10 biosynthetic pathway that resulted in improved yield. Hence, investigating the mutations responsible for deregulation of CoQ10 pathway is essential to understand the cause of overproduction in UF16. Phylogenetic analysis based on RAPD bands and rRNA gene sequences coupled with morphological variations, exhibited the novelty of mutant UF16 having potential for improved CoQ10 production.
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Affiliation(s)
- Prafull Ranadive
- Fermentation Technology Lab, Natural Products Department, Piramal Enterprises Limited, Nirlon Complex, Off Western Express Highway, Goregaon (East), Mumbai, 400063 India
| | - Alka Mehta
- School of Bio Science and Technology, VIT University, Vellore, 632014 Tamil Nadu India
| | - Yashwant Chavan
- geneOmbio Technologies Private Limited, Baner, Pune, 411045 Maharashtra India
| | - Anbukayalvizhi Marx
- Fermentation Technology Lab, Natural Products Department, Piramal Enterprises Limited, Nirlon Complex, Off Western Express Highway, Goregaon (East), Mumbai, 400063 India
| | - Saji George
- Fermentation Technology Lab, Natural Products Department, Piramal Enterprises Limited, Nirlon Complex, Off Western Express Highway, Goregaon (East), Mumbai, 400063 India
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Tikh IB, Held M, Schmidt-Dannert C. BioBrick™ compatible vector system for protein expression in Rhodobacter sphaeroides. Appl Microbiol Biotechnol 2014; 98:3111-9. [PMID: 24509770 DOI: 10.1007/s00253-014-5527-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 01/09/2014] [Accepted: 01/10/2014] [Indexed: 11/30/2022]
Abstract
We report here the creation of a modular, plasmid-based protein expression system utilizing elements of the native Rhodobacter puf promoter in a BioBrick(TM)-based vector system with DsRed encoding a red fluorescent reporter protein. A suite of truncations of the puf promoter were made to assess the influence of different portions of this promoter on expression of heterologous proteins. The 3' end of puf was found to be particularly important for increasing expression, with transformants accumulating significant quantities of DsRed under both aerobic and anaerobic growth conditions. Expression levels of this reporter protein in Rhodobacter sphaeroides were comparable to those achieved in Escherichia coli using the strong, constitutive P lac promoter, thus demonstrating the robustness of the engineered system. Furthermore, we demonstrate the ability to tune the designed expression system by modulating cellular DsRed levels based upon the promoter segment utilized and oxygenation conditions. Last, we show that the new expression system is able to drive expression of a membrane protein, proteorhodopsin, and that membrane purifications from R. sphaeroides yielded significant quantities of proteorhodopsin. This toolset lays the groundwork for the engineering of multi-step pathways, including recalcitrant membrane proteins, in R. sphaeroides.
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Affiliation(s)
- Ilya B Tikh
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, 140 Gortner Laboratory, 1479 Gortner Avenue, St. Paul, MN, 55108, USA
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Tokdar P, Ranadive P, Kshirsagar R, Khora SS, Deshmukh SK. Influence of Substrate Feeding and Process Parameters on Production of Coenzyme Q<sub>10</sub> Using <i>Paracoccus denitrificans</i> ATCC 19367 Mutant Strain P-87. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/abb.2014.512110] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Wu HS, Tsai JJ. Separation and purification of coenzyme Q10 from Rhodobacter sphaeroides. J Taiwan Inst Chem Eng 2013. [DOI: 10.1016/j.jtice.2013.03.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Imam S, Noguera DR, Donohue TJ. Global insights into energetic and metabolic networks in Rhodobacter sphaeroides. BMC SYSTEMS BIOLOGY 2013; 7:89. [PMID: 24034347 PMCID: PMC3849096 DOI: 10.1186/1752-0509-7-89] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 09/10/2013] [Indexed: 11/29/2022]
Abstract
Background Improving our understanding of processes at the core of cellular lifestyles can be aided by combining information from genetic analyses, high-throughput experiments and computational predictions. Results We combined data and predictions derived from phenotypic, physiological, genetic and computational analyses to dissect the metabolic and energetic networks of the facultative photosynthetic bacterium Rhodobacter sphaeroides. We focused our analysis on pathways crucial to the production and recycling of pyridine nucleotides during aerobic respiratory and anaerobic photosynthetic growth in the presence of an organic electron donor. In particular, we assessed the requirement for NADH/NADPH transhydrogenase enzyme, PntAB during respiratory and photosynthetic growth. Using high-throughput phenotype microarrays (PMs), we found that PntAB is essential for photosynthetic growth in the presence of many organic electron donors, particularly those predicted to require its activity to produce NADPH. Utilizing the genome-scale metabolic model iRsp1095, we predicted alternative routes of NADPH synthesis and used gene expression analyses to show that transcripts from a subset of the corresponding genes were conditionally increased in a ΔpntAB mutant. We then used a combination of metabolic flux predictions and mutational analysis to identify flux redistribution patterns utilized in the ΔpntAB mutant to compensate for the loss of this enzyme. Data generated from metabolic and phenotypic analyses of wild type and mutant cells were used to develop iRsp1140, an expanded genome-scale metabolic reconstruction for R. sphaeroides with improved ability to analyze and predict pathways associated with photosynthesis and other metabolic processes. Conclusions These analyses increased our understanding of key aspects of the photosynthetic lifestyle, highlighting the added importance of NADPH production under these conditions. It also led to a significant improvement in the predictive capabilities of a metabolic model for the different energetic lifestyles of a facultative organism.
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Affiliation(s)
- Saheed Imam
- Department of Bacteriology, University of Wisconsin, Madison, Suite 5166, Wisconsin Energy Institute, 1552 University Avenue, Madison, WI 53726-4084, USA.
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Abstract
Coenzyme Q10 has emerged as a valuable molecule for pharmaceutical and cosmetic applications. Therefore, research into producing and optimizing coenzyme Q10 via microbial fermentation is ongoing. There are two major paths being explored for maximizing production of this molecule to commercially advantageous levels. The first entails using microbes that naturally produce coenzyme Q10 as fermentation biocatalysts and optimizing the fermentation parameters in order to reach industrial levels of production. However, the natural coenzyme Q10-producing microbes tend to be intractable for industrial fermentation settings. The second path to coenzyme Q10 production being explored is to engineer Escherichia coli with the ability to biosynthesize this molecule in order to take advantage of its more favourable fermentation characteristics and the well-understood array of genetic tools available for this bacteria. Although many studies have attempted to over-produce coenzyme Q10 in E. coli through genetic engineering, production titres still remain below those of the natural coenzyme Q10-producing microorganisms. Current research is providing the knowledge needed to alleviate the bottlenecks involved in producing coenzyme Q10 from an E. coli strain platform and the fermentation parameters that could dramatically increase production titres from natural microbial producers. Synthesizing the lessons learned from both approaches may be the key towards a more cost-effective coenzyme Q10 industry.
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Affiliation(s)
- Corinne P Cluis
- Department of Biology, Concordia University, 7141 Sherbrooke West, Montréal, H4B 1R6, Québec, Canada
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Identification of bottlenecks in Escherichia coli engineered for the production of CoQ10. Metab Eng 2011; 13:733-44. [DOI: 10.1016/j.ymben.2011.09.009] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Revised: 09/07/2011] [Accepted: 09/26/2011] [Indexed: 12/30/2022]
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Hädicke O, Grammel H, Klamt S. Metabolic network modeling of redox balancing and biohydrogen production in purple nonsulfur bacteria. BMC SYSTEMS BIOLOGY 2011; 5:150. [PMID: 21943387 PMCID: PMC3203349 DOI: 10.1186/1752-0509-5-150] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Accepted: 09/25/2011] [Indexed: 02/05/2023]
Abstract
Background Purple nonsulfur bacteria (PNSB) are facultative photosynthetic bacteria and exhibit an extremely versatile metabolism. A central focus of research on PNSB dealt with the elucidation of mechanisms by which they manage to balance cellular redox under diverse conditions, in particular under photoheterotrophic growth. Results Given the complexity of the central metabolism of PNSB, metabolic modeling becomes crucial for an integrated analysis of the accumulated biological knowledge. We reconstructed a stoichiometric model capturing the central metabolism of three important representatives of PNSB (Rhodospirillum rubrum, Rhodobacter sphaeroides and Rhodopseudomonas palustris). Using flux variability analysis, the model reveals key metabolic constraints related to redox homeostasis in these bacteria. With the help of the model we can (i) give quantitative explanations for non-intuitive, partially species-specific phenomena of photoheterotrophic growth of PNSB, (ii) reproduce various quantitative experimental data, and (iii) formulate several new hypotheses. For example, model analysis of photoheterotrophic growth reveals that - despite a large number of utilizable catabolic pathways - substrate-specific biomass and CO2 yields are fixed constraints, irrespective of the assumption of optimal growth. Furthermore, our model explains quantitatively why a CO2 fixing pathway such as the Calvin cycle is required by PNSB for many substrates (even if CO2 is released). We also analyze the role of other pathways potentially involved in redox metabolism and how they affect quantitatively the required capacity of the Calvin cycle. Our model also enables us to discriminate between different acetate assimilation pathways that were proposed recently for R. sphaeroides and R. rubrum, both lacking the isocitrate lyase. Finally, we demonstrate the value of the metabolic model also for potential biotechnological applications: we examine the theoretical capabilities of PNSB for photoheterotrophic hydrogen production and identify suitable genetic interventions to increase the hydrogen yield. Conclusions Taken together, the metabolic model (i) explains various redox-related phenomena of the versatile metabolism of PNSB, (ii) delivers new hypotheses on the operation and relevance of several metabolic pathways, and (iii) holds significant potential as a tool for rational metabolic engineering of PNSB in biotechnological applications.
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Affiliation(s)
- Oliver Hädicke
- Max Planck Institute for Dynamics of Complex Technical Systems, Sandtorstrasse 1, D-39106 Magdeburg, Germany
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Improvement of cultivation medium for enhanced production of coenzyme Q10 by photosynthetic Rhodospirillum rubrum. Biochem Eng J 2010. [DOI: 10.1016/j.bej.2010.06.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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