|
|
|
| Genetic Engineering Modification of Microalgae to Enhance CO2 Fixation and Oil Formation |
| YU Shui-yan, ZHAO Quan-yu, SHI Ji-ping |
| Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China |
|
|
|
Abstract Fossil fuels are un-renewable and over-emission of CO2 brings on the global warming. Biodiesel from microalgae is considered as a potential alternative energy. CO2 could be fixed by microalgae via photosynthesis to synthesize the oil. Microalgal biodiesel is further produced by trans-esterification of triglycerides with methanol. There are several advantages of microalgae biodiesel compared with other biofuels. Microalgae as a next generation feedstock for biofuel production have obtained worldwide attention. The neutral lipids especially triacylglycerols (TAG) which are the main feedstock of oil can be accumulated in many microalgae cells under stress conditions. Three promising strategies are feasible to enhance TAG accumulation in microalgae: the biochemical engineering approach, the genetic engineering (GE) approach, and the transcription factor engineering approach. The genetic engineering modification has now become a new research hot point to enhance the lipid production in oil-rich microalgae. An overview of the advances of some genes in lipid biosynthesis pathway in microalgae, and the metabolic regulation strategies for enhancing lipid accumulation was presented. Correlated with the TAG accumulating, some genes in six metabolic pathways are summarized including carbon fixation, central carbon metabolism, fatty acid biosynthesis, TAG assembling, inhibition of competing pathways of TAG and the lipid degradation catabolism. Exploring these enzymes and their functions involved in the pathways are helpful for the genetic engineering modification of microalgae. Finally, the current genetic engineering methods and technical issues of microalgae, the feasibility of genetic engineering modification of microalgae and possibilities of microalgae as feedstock for biofuels and its integrated utilization are further discussed.
|
|
Received: 10 September 2012
Published: 25 December 2012
|
|
|
|
|
[1] 李涛,李爱芬,桑敏等,富油能源微藻的筛选及产油性能评价.中国生物工程杂志,2011,31(4): 98-105. Li T, Li A F, Sang M, et al. Screening oleaginous microalgae and evaluation of the oil-producing characteristic.China Biotechnology, 2011,31(4): 98-105.
[2] Hu Q, Sommerfeld M, Jarvis E, et al. Microalgal triacylglycerols as feedstocks for biofuel production: perspectives and advances. Plant J, 2008, 54: 621-639.
[3] Malcata F X. Microalgae and biofuels: A promising partnership? Trends in Biotech, 2011, 29(11): 542-549.
[4] 唐小红,常影,黄和等,微藻在CO2生物捕集及废水生态修复领域的研究进展。中国生物工程杂志,2011,31(9):124-131. Tang X H, Chang Y, Huang H, et al. The advancement of CO2 biological trapping and wastewater ecological recovery based on microalgae cultivation.China Biotechnology, 2011,31(9):124-131.
[5] 郑洪立,张齐,马小琛等,产生物柴油微藻培养研究进展.中国生物工程杂志,2009,29(3): 110-116. Zheng H L, Zhang Q, Ma X C, et al. Research progress on bio-diesel-producing microalgae cultivation.China Biotechnology, 2009,29(3): 110-116.
[6] 夏金兰,万民熙,王润民等,微藻生物柴油的现状与进展.中国生物工程杂志,2009,29(7): 118-126. Xia J L, Wan M X, Wang R M, et al. Current status and progress of microalgal biodiesel.China Biotechnology, 2009,29(7): 118-126.
[7] 姜进举,苗凤萍,冯大伟等,微藻生物柴油技术的研究现状及展望.中国生物工程杂志,2010,30(2): 134-140. Jiang J J, Miao F P, Feng D W, et al. Research situation and prospect of microalgae biodiesel.China Biotechnology, 2010,30(2): 134-140.
[8] Wijffels R H, Barbosa M J. An outlook on microalgal biofuels. Science, 2010, 329: 796-799.
[9] Scott S A, Davey M P, Dennis J S, et al. Biodiesel from algae: challenges and prospects. Curr Opin Biotechnol, 2010, 21: 277-286.
[10] Work V H, D(Adamo S, Radakovits R, et al. Improving photosynthesis and metabolic networks for the competitive production of phototroph-derived biofuels. Curr Opin Biotechnol, 2012, 23: 290-297.
[11] Sayre R. Microalgae: the potential for carbon capture. Bioscience, 2010, 60: 722-727.
[12] Spalding M H. Microalgal carbon -dioxide-concentrating mechanisms: Chlamydomonas inorganic carbon transporters. Journal of Experimental Botany, 2008, 59: 1463-1473.
[13] Mamedov T G, Moellering E R, Chollet R. Identification and expression analysis of two inorganic C- and N-responsive genes encoding novel and distinct molecular forms of eukaryotic phosphoenolpyruvate carboxylase in the green microalga Chlamydomonas reinhardtii. Plant J, 2005, 42: 832-843.
[14] Taylor L, Nunes-Nesi A, Parsley K, et al. Cytosolic pyruvate orthophosphate dikinase functions in nitrogen remobilization during leaf senescence and limits individual seed growth and nitrogen content. Plant J, 2010, 62: 641-652
[15] Miller R, Wu G X, Deshpande R R, et al. Changes in transcript abundance in Chlamydomonas reinhardtii following nitrogen deprivation predict diversion of metabolism. Plant Physiol, 2010, 154(4): 1737-1752.
[16] Yu S Y, Li H, Tong M, et al. Identification of a Δω6 fatty acid elongase gene for arachidonic acid biosynthesis localized to the endoplasmic reticulum in the green microalga, Myrmecia incisa Reisigl. Gene, 2012, 493: 219-227.
[17] Khozin-Goldberg I, Cohen Z. Unraveling algal lipid metabolism: Recent advances in gene identification. Biochimie, 2011, 93: 91-100.
[18] Maisonneuve S, Bessoule J J, Lessire R, et al. Expression of rapeseed microsomal lysophosphatidic acid acyltransferase isozymes enhances seed oil content in Arabidopsis. Plant Physiol, 2010, 152: 670-684.
[19] Wagner M, Hoppe K, Czabany T, et al. Identification and characterization of an acyl-CoA:diacylglycerol acyltransferase 2 (DGAT2) gene from the microalga Ostreococcus tauri. Plant Physiol Biochem, 2010, 48: 407-416.
[20] Dahlqvist A, Stahl U, Lenman M, et al. Phospholipid:diacylglycerol acyltransferase: an enzyme that catalyzes the acyl-CoA-independent formation of triacylglycerol in yeast and plants. Proc Natl Acad Sci USA, 2000, 97: 6487-6492.
[21] Boyle N R, Page M D, Liu B S, et al. Three acyltransferases and nitrogen-responsive regulator are implicated in nitrogen starvation-induced triacylglycerol accumulation in Chlamydomonas. J Biological Chemistry, 2012, 287(19): 15811-15825.
[22] Xu J, Zheng Z, Zou J. A membrane-bound glycerol-3-phosphate acyltransferase from Thalassiosira pseudonana regulates acyl composition of glycerolipids. Botany, 2009, 87: 544-551.
[23] Chen Q, Zou J, Zheng Z, et al. Genes encoding a novel type of lysophosphatidylcholine acyltransferases and their use to increase triacylglycerols production and/or modify fatty acid composition, US Patent Application 2010/0016431 A1, 2010.
[24] Molnar A, Bassett A, Thuenemann E, et al. Highly specific gene silencing by artificial microRNAs in the unicellular alga Chlamydomonas reinhardtii. Plant, 2009, 58: 165-174.
[25] Roessler P G. Changes in the activities of various lipid and carbohydrate biosynthetic enzymes in the diatom Cyclotella cryptica in response to silicon deficiency. Archives of Biochemistry and Biophysics, 1988, 24(3): 394-400.
[26] Zabawinski C, van Den Koornhuyse N, Schlichting R, et al. Starchless mutants of Chlamydomonas reinhardtii lack the small subunit of a heterotetrameric ADP-glucose pyrophosphorylase. J Bacteriol, 2001, 183: 1069-1077.
[27] Li Y, Han D, Hu G, et al. Chlamydomonas starchless mutant defective in ADP-glucose pyrophosphorylase hyper-accumulates triacylglycerol. Metabolic Engineering, 2010, 12(4): 387-391.
[28] Li Y, Han D, Hu G, et al. Inhibition of starch synthesis results in overproduction of lipids in Chlamydomonas reinhardtii. Biotechnology and bioengineering, 2010, 107(2): 258-268.
[29] Work V H, Radakovits R, Jinkerson R E, et al. Increased lipid accumulation in the Chlamydomonas reinhardtii sta7-10 starchless Isoamylase mutant and increased carbohydrate synthesis in complemented strains. Eukaryot Cell, 2010, 9(8): 1251-1261.
[30] Siaut M, Cuine S, Cagnon C, et al. Oil accumulation in the model green alga Chlamydomonas reinhardtii: characterization, variability between common laboratory strains and relationship with starch reserves. BMC Biotechnology, 2011, 11: 7-21.
[31] Radakovits R, Jinkerson R E, Darzins A, et al. Genetic engineering of algae for enhanced biofuel production. Eukaryot Cell, 2010, 9: 486-501.
[32] Kumar S V, Misquitta R W, Reddy V S, et al. Genetic transformation of the green alga Chlamydomonas reinhardtii by Agrobacterium tumefaciens. Plant Sci, 2004, 166: 731-738.
[33] Deng X D, Li Y J, Fei X W. The mRNA abundance of pepc2 gene is negatively correlated with oil content in Chlamydomonas reinhardtii. Biomass Bioenerg, 2011, 35(5): 1811-1817.
[34] Riso D, Raniello V R, Maumus F, et al. Gene silencing in the marine diatom Phaeodactylum tricornutum. Nucleic Acids Res, 2009, 37: 96-108.
[35] Molnar A, Bassett A, Thuenemann E, et al. Highly specific gene silencing by artificial microRNAs in the unicellular alga Chlamydomonas reinhardtii. Plant, 2009, 58: 165-174.
[36] Zhao T, Wang W, Bai X, et al. Gene silencing by artificial microRNAs in Chlamydomonas. Plant, 2009, 58: 157-164.
[37] Liu X, Sheng J, Curtiss I R. Fatty acid production in genetically modified cyanobacteria. Proc Natl Acad Sci USA, 2011, 108(17): 6899-6904.
[38] Merchant S S, Kropat J, Liu B S, et al. TAG, you’re it! Chlamydomonas as a reference organism for understanding algal triacylglycerol accumulation. Curr Opin Biotechnol, 2012, 23: 352-363.
[39] Sodeinde O A, Kindle K L. Homologous recombination in the nuclear genome of Chlamydomonas reinhardtii. Proc Natl Acad Sci USA, 1993, 90: 9199-9203.
[40] Berthold D A, Schmidt C L, Malkin R. The deletion of petG in Chlamydomonas reinhardtii disrupts the cytochrome bf complex. Biolog Chemis, 1995, 270(49): 29293-29298.
[41] Kilian O, Benemann C S, Niyogi K K, et al. High-efficiency homologous recombination in the oil-producing alga Nannochloropsis sp. Proc Natl Acad Sci USA, 2011, 108(52): 21265-21269.
[42] Lü J, Sheahan C, Fu P. Metabolic engineering of algae for fourth generation biofuels production. Energy and Environmental Science, 2011, 4(7): 2451-2466.
[43] Zhao Q Y, Kurata H. Genetic modification of flux for flux prediction of mutants. Bioinformatics, 2009, 25(13): 1702-1708. |
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
| |
Shared |
|
|
|
|
| |
Discussed |
|
|
|
|
