The synthesis of renewable bioproducts using photosynthetic microorganisms holds great promise. Sustainable industrial applications, however, are still scarce and the true limits of phototrophic production remain unknown. One of the limitations of further progress is our insufficient understanding of the quantitative changes in photoautotrophic metabolism that occur during growth in dynamic environments. We argue that a proper evaluation of the intra- and extracellular factors that limit phototrophic production requires the use of highly-controlled cultivation in photobioreactors, coupled to real-time analysis of production parameters and their evaluation by predictive computational models. In this addendum, we discuss the importance and challenges of systems biology approaches for the optimization of renewable biofuels production. As a case study, we present the utilization of a state-of-the-art experimental setup together with a stoichiometric computational model of cyanobacterial metabolism for quantitative evaluation of ethylene production by a recombinant cyanobacterium Synechocystis sp. PCC 6803.

b Institut für Theoretische Biologie Humboldt Universität zu Berlin Berlin Germany

Department of Adaptive Biotechnologies Global Change Research Institute Academy of Science of the Czech Republic Drásov Czech Republic

Addendum to: Zavřel T, Knoop H, Steuer R, Jones PR, Červený J, Trtílek M. A quantitative evaluation of ethylene production in the recombinant cyanobacterium Synechocystis sp. PCC 6803 harboring the ethylene-forming enzyme by membrane inlet mass spectrometry. Bioresour. Technol. 2016; 202:142-151; doi: 10.1016/j.biortech.2015.11.062 PubMed

Zobrazit více v PubMed

Fukuda H, Ogawa T, Tanase S. Ethylene production by micro-organisms. Adv Microb Physiol 1993; 35:275-306. http://www.ncbi.nlm.nih.gov/pubmed/9892551; PMID:8310882; http://dx.doi.org/10.1016/S0065-2911(08)60101-0 PubMed DOI

Eckert C, Xu W, Xiong W, Lynch S, Ungerer J, Tao L, Gill R, Maness PC, Yu J. Ethylene-forming enzyme and bioethylene production. Biotechnol Bio Fuels 2014; 7:1-11. http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=3946592&tool=pmcentrez&rendertype=abstract; PMID:24387051; http://dx.doi.org/10.1186/1754-6834-7-33 PubMed DOI PMC

Ungerer J, Tao L, Davis M, Ghirardi M, Maness PC, Yu J. Sustained photosynthetic conversion of CO2 to ethylene in recombinant cyanobacterium Synechocystis 6803. Energy Environ Sci 2012; 5:8998-9006. http://xlink.rsc.org/?DOI=c2ee22555g; http://dx.doi.org/10.1039/c2ee22555g DOI

Klamt S, Mahadevan R. On the feasibility of growth-coupled product synthesis in microbial strains. Metab Eng 2015; 30:166-78. http://www.ncbi.nlm.nih.gov/pubmed/26112955; PMID:26112955; http://dx.doi.org/10.1016/j.ymben.2015.05.006 PubMed DOI

Baroukh C, Muñoz-Tamayo R, Steyer JP, Bernard O. A state of the art of metabolic networks of unicellular microalgae and cyanobacteria for biofuel production. Metab Eng 2015; 30:49-60; PMID:25916794; http://dx.doi.org/10.1016/j.ymben.2015.03.019 PubMed DOI

Guerrero F, Carbonell V, Cossu M, Correddu D, Jones PR. Ethylene synthesis and regulated expression of recombinant protein in Synechocystis sp PCC 6803. PLoS One 2012; 7:e50470. http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=3503970&tool=pmcentrez&rendertype=abstract; PMID:23185630; http://dx.doi.org/10.1371/journal.pone.0050470 PubMed DOI PMC

Zavřel T, Sinetova MA, Búzová D, Literáková P, Červený J. Characterization of a model cyanobacterium Synechocystis sp. PCC 6803 autotrophic growth in a flat-panel photobioreactor. Eng Life Sci 2015; 15:122-32; http://doi.wiley.com/10.1002/elsc.201300165; http://dx.doi.org/10.1002/elsc.201300165 DOI

Nedbal L, Trtílek M, Cervený J, Komárek O, Pakrasi HB. A photobioreactor system for precision cultivation of photoautotrophic microorganisms and for high-content analysis of suspension dynamics. Biotechnol Bioeng 2008; 100:902-10; http://www.ncbi.nlm.nih.gov/pubmed/18383143; PMID:18383143; http://dx.doi.org/10.1002/bit.21833 PubMed DOI

Sinetova MA, Červený J, Zavřel T, Nedbal L. On the dynamics and constraints of batch culture growth of the cyanobacterium Cyanothece sp. ATCC 51142. J Biotechnol 2012; 162:148-55. http://www.ncbi.nlm.nih.gov/pubmed/22575787; PMID:22575787; http://dx.doi.org/10.1016/j.jbiotec.2012.04.009 PubMed DOI

Červený J, Šetlík I, Trtílek M, Nedbal L. Photobioreactor for cultivation and real-time, in-situ measurement of O2 and CO2 exchange rates, growth dynamics, and of chlorophyll fluorescence emission of photoautotrophic microorganisms. Eng Life Sci 2009; 9:247-53. http://doi.wiley.com/10.1002/elsc.200800123; http://dx.doi.org/10.1002/elsc.200800123 DOI

Knoop H, Zilliges Y, Lockau W, Steuer R. The metabolic network of Synechocystis sp. PCC 6803: systemic properties of autotrophic growth. Plant Physiol 2010; 154:410-22. http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2938163&tool=pmcentrez&rendertype=abstract; PMID:20616194; http://dx.doi.org/10.1104/pp.110.157198 PubMed DOI PMC

Zavřel T, Knoop H, Steuer R, Jones PR, Červený J, Trtílek M. A quantitative evaluation of ethylene production in the recombinant cyanobacterium Synechocystis sp. PCC 6803 harboring the ethylene-forming enzyme by membrane inlet mass spectrometry. Bio Resour Technol 2016; 202:142-51; PMID:26708481; http://dx.doi.org/10.1016/j.biortech.2015.11.062 PubMed DOI

Wijffels RH, Kruse O, Hellingwerf KJ. Potential of industrial biotechnology with cyanobacteria and eukaryotic microalgae. Curr Opin Biotechnol 2013; 24:405-13. http://www.ncbi.nlm.nih.gov/pubmed/23647970; PMID:23647970; http://dx.doi.org/10.1016/j.copbio.2013.04.004 PubMed DOI

Sarsekeyeva F, Zayadan BK, Usserbaeva A, Bedbenov VS, Sinetova MA, Los DA. Cyanofuels: Biofuels from cyanobacteria. Reality and perspectives. Photosynth Res 2015; 125:329-40; PMID:25702086; http://dx.doi.org/10.1007/s11120-015-0103-3 PubMed DOI

Gudmundsson S, Nogales J. Cyanobacteria as photosynthetic biocatalysts: a systems biology perspective. Mol Bio Syst 2015; 11:60-70. http://xlink.rsc.org/?DOI=C4MB00335G; PMID:25382198; http://dx.doi.org/10.1039/C4MB00335G PubMed DOI

Angermayr SA, Gorchs Rovira A, Hellingwerf KJ. Metabolic engineering of cyanobacteria for the synthesis of commodity products. Trends Biotechnol 2015; 33(6):352-61. http://linkinghub.elsevier.com/retrieve/pii/S0167779915000712 PubMed

Jones PR. Genetic instability in cyanobacteria – an elephant in the room? Synth Biol 2014; 2:12 http://journal.frontiersin.org/article/10.3389/fbioe.2014.00012/full\nhttp://journal.frontiersin.org/article/10.3389/fbioe.2014.00012/pdf PubMed DOI PMC

Berla BM, Saha R, Immethun CM, Maranas CD, Moon TS, Pakrasi HB. Synthetic biology of cyanobacteria: Unique challenges and opportunities. Front Microbiol 2013; 4:1-14; PMID:23346082; http://dx.doi.org/10.3389/fmicb.2013.00246 PubMed DOI PMC

Fernandes BD, Mota A, Teixeira JA, Vicente AA. Continuous cultivation of photosynthetic microorganisms: Approaches, applications and future trends. Biotechnol Adv 2015; 33(6 Pt 2):1228-45; PMID:25777495 PubMed

Xiong W, Morgan JA, Ungerer J, Wang B, Maness P, Yu J. The plasticity of cyanobacterial metabolism supports direct CO2 conversion to ethylene. Nat Plants 2015; 1:1-6

Pade N, Erdmann S, Enke H, Dethloff F, Dühring U, Georg J, Wambutt J, Kopka J, Hess WR, Zimmermann R, et al.. Insights into isoprene production using the cyanobacterium Synechocystis sp. PCC 6803. Biotechnol Biofuels 2016; 9:89. http://biotechnologyforbiofuels.biomedcentral.com/articles/10.1186/s13068-016-0503-4; PMID:27096007; http://dx.doi.org/10.1186/s13068-016-0503-4 PubMed DOI PMC

King ZA, Lloyd CJ, Feist AM, Palsson BO. Next-generation genome-scale models for metabolic engineering. Curr Opin Biotechnol 2015; 35:23-9; PMID:25575024; http://dx.doi.org/10.1016/j.copbio.2014.12.016 PubMed DOI

Nogales J, Gudmundsson S, Thiele I. Toward systems metabolic engineering in cyanobacteria: opportunities and bottlenecks. Bioengineered 2013; 4:158-63. http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=3669157&tool=pmcentrez&rendertype=abstract; PMID:23138691; http://dx.doi.org/10.4161/bioe.22792 PubMed DOI PMC

Erdrich P, Knoop H, Steuer R, Klamt S. Cyanobacterial biofuels: new insights and strain design strategies revealed by computational modeling. Microb Cell Fact 2014; 13:128. http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=4180434&tool=pmcentrez&rendertype=abstract; PMID:25323065; http://dx.doi.org/10.1186/s12934-014-0128-x PubMed DOI PMC

Knoop H, Steuer R. A Computational Analysis of stoichiometric constraints and trade-offs in cyanobacterial biofuel production. Front Bioeng Biotechnol 2015; 3:1-15. http://www.frontiersin.org/Synthetic_Biology/10.3389/fbioe.2015.00047/abstract; PMID:25654078; http://dx.doi.org/10.3389/fbioe.2015.00047 PubMed DOI PMC

Saha R, Liu D, Hoynes-O'Connor A, Liberton M, Yu J, Bhattacharyya-Pakrasi M, Balassy A, Zhang F, Moon TS, Maranas CD, et al.. Diurnal regulation of cellular processes in the cyanobacterium Synechocystis sp. strain PCC 6803: Insights from transcriptomic, fluxomic, and physiological analyses. MBio 2016; 7:e00464-16. http://mbio.asm.org/lookup/doi/10.1128/mBio.00464-16; PMID:27143387; http://dx.doi.org/10.1128/mBio.00464-16 PubMed DOI PMC

Final Report Summary - DIRECTFUEL (Direct biological conversion of solar energy to volatile hydrocarbon fuels by engineered cyanobacteria). Collaborative STREP project EC grant agreement 256808 [Internet] 2014 http://cordis.europa.eu/project/rcn/95914_en.html

Quantitative insights into the cyanobacterial cell economy