1
|
Nazloo EK, Danesh M, Sarrafzadeh MH, Moheimani NR, Ennaceri H. Biomass and hydrocarbon production from Botryococcus braunii: A review focusing on cultivation methods. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 926:171734. [PMID: 38508258 DOI: 10.1016/j.scitotenv.2024.171734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 03/13/2024] [Accepted: 03/13/2024] [Indexed: 03/22/2024]
Abstract
Botryococcus braunii has garnered significant attention in recent years due to its ability to produce high amounts of renewable hydrocarbons through photosynthesis. As the world shifts towards a greener future and seeks alternative sources of energy, the cultivation of B. braunii and the extraction of its hydrocarbons can potentially provide a viable solution. However, the development of a sustainable and cost-effective process for cultivating B. braunii is not without challenges. Compared to other microalgae, B. braunii grows very slowly, making it time-consuming and expensive to produce biomass. In response to these challenges, several efforts have been put into optimizing Botryococcus braunii cultivation systems to increase biomass growth and hydrocarbon production efficiency. This review presents a comparative analysis of different Botryococcus braunii cultivation systems, and the factors affecting the productivity of biomass and hydrocarbon in Botryococcus braunii are critically discussed. Attached microalgal growth offers several advantages that hold significant potential for enhancing the economic viability of microalgal fuels. Here, we propose that employing attached growth cultivation, coupled with the milking technique for hydrocarbon extraction, represents an efficient approach for generating renewable fuels from B. braunii. Nevertheless, further research is needed to ascertain the viability of large-scale implementation.
Collapse
Affiliation(s)
- Ehsan Khorshidi Nazloo
- UNESCO Chair on Water Reuse, School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran
| | - Moslem Danesh
- UNESCO Chair on Water Reuse, School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran; Department of Petroleum Drilling and Refining, Kurdistan Technical Institute Sulaimaniya, Iraq; Department of Biomedical Engineering, Qaiwan International University, Sulaimaniya, Iraq
| | - Mohammad-Hossein Sarrafzadeh
- UNESCO Chair on Water Reuse, School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran
| | - Navid Reza Moheimani
- Algae R&D Centre, Murdoch University, Murdoch, Western Australia 6150, Australia; Centre for Water, Energy and Waste, Harry Butler Institute, Murdoch University, Perth 6150, Australia
| | - Houda Ennaceri
- Algae R&D Centre, Murdoch University, Murdoch, Western Australia 6150, Australia; Centre for Water, Energy and Waste, Harry Butler Institute, Murdoch University, Perth 6150, Australia.
| |
Collapse
|
2
|
Rautela A, Kumar S. Engineering plant family TPS into cyanobacterial host for terpenoids production. PLANT CELL REPORTS 2022; 41:1791-1803. [PMID: 35789422 PMCID: PMC9253243 DOI: 10.1007/s00299-022-02892-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 06/05/2022] [Indexed: 05/03/2023]
Abstract
Terpenoids are synthesized naturally by plants as secondary metabolites, and are diverse and complex in structure with multiple applications in bioenergy, food, cosmetics, and medicine. This makes the production of terpenoids such as isoprene, β-phellandrene, farnesene, amorphadiene, and squalene valuable, owing to which their industrial demand cannot be fulfilled exclusively by plant sources. They are synthesized via the Methylerythritol phosphate pathway (MEP) and the Mevalonate pathway (MVA), both existing in plants. The advent of genetic engineering and the latest accomplishments in synthetic biology and metabolic engineering allow microbial synthesis of terpenoids. Cyanobacteria manifest to be the promising hosts for this, utilizing sunlight and CO2. Cyanobacteria possess MEP pathway to generate precursors for terpenoid synthesis. The terpenoid synthesis can be amplified by overexpressing the MEP pathway and engineering MVA pathway genes. According to the desired terpenoid, terpene synthases unique to the plant kingdom must be incorporated in cyanobacteria. Engineering an organism to be used as a cell factory comes with drawbacks such as hampered cell growth and disturbance in metabolic flux. This review set forth a comparison between MEP and MVA pathways, strategies to overexpress these pathways with their challenges.
Collapse
Affiliation(s)
- Akhil Rautela
- School of Biochemical Engineering, IIT (BHU), Varanasi, 221005, Uttar Pradesh, India
| | - Sanjay Kumar
- School of Biochemical Engineering, IIT (BHU), Varanasi, 221005, Uttar Pradesh, India.
| |
Collapse
|
3
|
Large-scale screening of natural genetic resource in the hydrocarbon-producing microalga Botrycoccus braunii identified novel fast-growing strains. Sci Rep 2021; 11:7368. [PMID: 33811231 PMCID: PMC8018972 DOI: 10.1038/s41598-021-86760-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 03/18/2021] [Indexed: 12/04/2022] Open
Abstract
Algal biofuel research aims to make a renewable, carbon–neutral biofuel by using oil-producing microalgae. The freshwater microalga Botryococcus braunii has received much attention due to its ability to accumulate large amounts of petroleum-like hydrocarbons but suffers from slow growth. We performed a large-scale screening of fast-growing strains with 180 strains isolated from 22 ponds located in a wide geographic range from the tropics to cool-temperate. A fast-growing strain, Showa, which recorded the highest productivities of algal hydrocarbons to date, was used as a benchmark. The initial screening was performed by monitoring optical densities in glass tubes and identified 9 wild strains with faster or equivalent growth rates to Showa. The biomass-based assessments showed that biomass and hydrocarbon productivities of these strains were 12–37% and 11–88% higher than that of Showa, respectively. One strain, OIT-678 established a new record of the fastest growth rate in the race B strains with a doubling time of 1.2 days. The OIT-678 had 36% higher biomass productivity, 34% higher hydrocarbon productivity, and 20% higher biomass density than Showa at the same cultivation conditions, suggesting the potential of the new strain to break the record for the highest productivities of hydrocarbons.
Collapse
|
4
|
Australian Strains of Botryococcus braunii Examined for Potential Hydrocarbon and Carotenoid Pigment Production and the Effect of Brackish Water. ENERGIES 2020. [DOI: 10.3390/en13246644] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The green alga Botryococcus braunii produces abundant hydrocarbons, in the form of drop-in biodiesel, which promoted interest in the species as a renewable fuel. However, despite the observation of dense populations in the wild, Botryococcus grows very slowly in culture, severely limiting its potential for development as a bioresource. Undertaking a biodiscovery program, we found new strains of Botryococcus in locations ranging from tropical to temperate Australia and from both fresh and brackish waters. As part of the ecophysiological characterisation of this new biodiversity, lipid and pigment compositions were studied for six new strains from six different locations. The strains were inoculated in either freshwater or brackish (salinity of 4)-based medium and maintained over 150 days. The growth of cultures was studied continuously, while lipid and pigment composition were analysed at final harvest on day 150. No significant differences in growth rate between fresh and brackish media were observed. Some strains were more tolerable of brackish conditions than others with a link between salinity tolerance and original location. The use of lower salinity (4 ppt) had a minimal effect on lipid composition, with only two of the six strains showing a different hydrocarbon profile in comparison to the other strains; pigment composition showed only minor variations for fresh and brackish water cultures, although the concentrations varied significantly with the freshwater cultures containing higher pigment concentrations.
Collapse
|
5
|
Cheng P, Okada S, Zhou C, Chen P, Huo S, Li K, Addy M, Yan X, Ruan RR. High-value chemicals from Botryococcus braunii and their current applications - A review. BIORESOURCE TECHNOLOGY 2019; 291:121911. [PMID: 31383389 DOI: 10.1016/j.biortech.2019.121911] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 07/24/2019] [Accepted: 07/25/2019] [Indexed: 06/10/2023]
Abstract
Botryococcus braunii is known for its high yield of extracellular hydrocarbons and polysaccharides. Hydrocarbons, especially botryococcenes and squalene can be used as not only fuels but also alternative feedstock for other fossil-based products. Exopolysaccharides excreted from B. braunii can be used as scaffolds for polyesters production, and have a notable potential for synthesis of nanoparticles. B. braunii is also a rich source of carotenoids, especially the unique secondary carotenoids such as botryoxanthins that have never been found in other microalgae. The morphology, physiology, and outer cell walls of B. braunii are complex. Understanding the colony structure shall provide insights into the mechanism of cell growth and chemicals secretion. It is possible to improve the production economics of the alga with advanced culture systems. Moreover, investigation of metabolic pathways for B. braunii may help us understand their regulation and provide valuable information for strain selection and optimal production of high-value chemicals.
Collapse
Affiliation(s)
- Pengfei Cheng
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, Zhejiang 315211, China; Department of Bioproducts and Biosystems Engineering, University of Minnesota-Twin Cities, Saint Paul, MN 55108, USA
| | - Shigeru Okada
- Department of Aquatic Biosciences, The University of Tokyo, Bunkyo, Tokyo 113-8657, Japan
| | - Chengxu Zhou
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, Zhejiang 315211, China
| | - Paul Chen
- Department of Bioproducts and Biosystems Engineering, University of Minnesota-Twin Cities, Saint Paul, MN 55108, USA
| | - Shuhao Huo
- Department of Bioproducts and Biosystems Engineering, University of Minnesota-Twin Cities, Saint Paul, MN 55108, USA
| | - Kun Li
- Department of Bioproducts and Biosystems Engineering, University of Minnesota-Twin Cities, Saint Paul, MN 55108, USA
| | - Min Addy
- Department of Bioproducts and Biosystems Engineering, University of Minnesota-Twin Cities, Saint Paul, MN 55108, USA
| | - Xiaojun Yan
- Key Laboratory of Marine Biotechnology of Zhejiang Province, Ningbo University, Ningbo, Zhejiang 315211, China
| | - Roger R Ruan
- Department of Bioproducts and Biosystems Engineering, University of Minnesota-Twin Cities, Saint Paul, MN 55108, USA.
| |
Collapse
|
6
|
Kempinski C, Jiang Z, Zinck G, Sato SJ, Ge Z, Clemente TE, Chappell J. Engineering linear, branched-chain triterpene metabolism in monocots. PLANT BIOTECHNOLOGY JOURNAL 2019; 17:373-385. [PMID: 29979490 PMCID: PMC6335073 DOI: 10.1111/pbi.12983] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 06/20/2018] [Accepted: 06/22/2018] [Indexed: 05/09/2023]
Abstract
Triterpenes are thirty-carbon compounds derived from the universal five-carbon prenyl precursors isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). Normally, triterpenes are synthesized via the mevalonate (MVA) pathway operating in the cytoplasm of eukaryotes where DMAPP is condensed with two IPPs to yield farnesyl diphosphate (FPP), catalyzed by FPP synthase (FPS). Squalene synthase (SQS) condenses two molecules of FPP to generate the symmetrical product squalene, the first committed precursor to sterols and most other triterpenes. In the green algae Botryococcus braunii, two FPP molecules can also be condensed in an asymmetric manner yielding the more highly branched triterpene, botryococcene. Botryococcene is an attractive molecule because of its potential as a biofuel and petrochemical feedstock. Because B. braunii, the only native host for botryococcene biosynthesis, is difficult to grow, there have been efforts to move botryococcene biosynthesis into organisms more amenable to large-scale production. Here, we report the genetic engineering of the model monocot, Brachypodium distachyon, for botryococcene biosynthesis and accumulation. A subcellular targeting strategy was used, directing the enzymes (botryococcene synthase [BS] and FPS) to either the cytosol or the plastid. High titres of botryococcene (>1 mg/g FW in T0 mature plants) were obtained using the cytosolic-targeting strategy. Plastid-targeted BS + FPS lines accumulated botryococcene (albeit in lesser amounts than the cytosolic BS + FPS lines), but they showed a detrimental phenotype dependent on plastid-targeted FPS, and could not proliferate and survive to set seed under phototrophic conditions. These results highlight intriguing differences in isoprenoid metabolism between dicots and monocots.
Collapse
Affiliation(s)
- Chase Kempinski
- Plant Biology ProgramUniversity of KentuckyLexingtonKYUSA
- Department of Pharmaceutical SciencesUniversity of KentuckyLexingtonKYUSA
| | - Zuodong Jiang
- Plant Biology ProgramUniversity of KentuckyLexingtonKYUSA
- Department of Pharmaceutical SciencesUniversity of KentuckyLexingtonKYUSA
- Present address:
Department of Soil and Crop SciencesTexas A&M UniversityCollege StationTX77843USA
| | - Garrett Zinck
- Department of Pharmaceutical SciencesUniversity of KentuckyLexingtonKYUSA
| | - Shirley J. Sato
- Center for BiotechnologyUniversity of Nebraska‐LincolnLincolnNEUSA
| | - Zhengxiang Ge
- Center for BiotechnologyUniversity of Nebraska‐LincolnLincolnNEUSA
| | | | - Joe Chappell
- Plant Biology ProgramUniversity of KentuckyLexingtonKYUSA
- Department of Pharmaceutical SciencesUniversity of KentuckyLexingtonKYUSA
| |
Collapse
|
7
|
Cormier M, de la Torre A, Marek I. Total Synthesis of C30 Botryococcene and
epi
‐Botryococcene by a Diastereoselective Ring Opening of Alkenylcyclopropanes. Angew Chem Int Ed Engl 2018; 57:13237-13241. [DOI: 10.1002/anie.201808709] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 08/22/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Morgan Cormier
- Technion—Israel Institute of TechnologySchulich Faculty of Chemistry Technion City Haifa 32000 Israel
| | - Aurélien de la Torre
- Technion—Israel Institute of TechnologySchulich Faculty of Chemistry Technion City Haifa 32000 Israel
| | - Ilan Marek
- Technion—Israel Institute of TechnologySchulich Faculty of Chemistry Technion City Haifa 32000 Israel
| |
Collapse
|
8
|
Cormier M, de la Torre A, Marek I. Total Synthesis of C30 Botryococcene and
epi
‐Botryococcene by a Diastereoselective Ring Opening of Alkenylcyclopropanes. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201808709] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Morgan Cormier
- Technion—Israel Institute of TechnologySchulich Faculty of Chemistry Technion City Haifa 32000 Israel
| | - Aurélien de la Torre
- Technion—Israel Institute of TechnologySchulich Faculty of Chemistry Technion City Haifa 32000 Israel
| | - Ilan Marek
- Technion—Israel Institute of TechnologySchulich Faculty of Chemistry Technion City Haifa 32000 Israel
| |
Collapse
|
9
|
Uchida H, Sumimoto K, Oki T, Nishii I, Mizohata E, Matsunaga S, Okada S. Isolation and characterization of 4-hydroxy-3-methylbut-2-enyl diphosphate reductase gene from Botryococcus braunii, race B. JOURNAL OF PLANT RESEARCH 2018; 131:839-848. [PMID: 29725892 DOI: 10.1007/s10265-018-1039-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 04/12/2018] [Indexed: 05/27/2023]
Abstract
The B race of a green microalga Botryococcus braunii Kützing produces triterpene hydrocarbons that is a promising source for biofuel. In this algal race, precursors of triterpene hydrocarbons are provided from the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway. The terminal enzyme of this pathway, 4-hydroxy-3-methylbut-2-enyl diphosphate reductase (HDR) is regarded as one of the key enzymes that affect yields of products in terpene biosynthesis. In order to better understand the MEP pathway of the alga, cDNA and genomic clones of HDR were obtained from B. braunii Showa strain. B. braunii HDR (BbHDR) is encoded on a single copy gene including a 1509-bp open reading frame that was intervened by 6 introns. The exon-intron structure of BbHDR genes did not show clear relation to phylogeny, while its amino acid sequence reflected phyla and classes well. BbHDR sequence was distinctive from that of the HDR protein from Escherichia coli in the residues involved in hydrogen-bond network that surrounds substrate. Introduction of BbHDR cDNA into an E. coli HDR deficient mutant resulted in recovery of its auxotrophy. BbHDR expression level was upregulated from the onset of liquid culture to the 24th day after inoculation with a 2.5-fold increase and retained its level in the subsequent period.
Collapse
Affiliation(s)
- Hidenobu Uchida
- Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo, 113-8657, Japan
- Japan Science and Technology Agency-Core Research for Evolutional Science and Technology (CREST), Gobancho, Chiyoda, Tokyo, 102-0076, Japan
| | - Koremitsu Sumimoto
- Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo, 113-8657, Japan
- Japan Science and Technology Agency-Core Research for Evolutional Science and Technology (CREST), Gobancho, Chiyoda, Tokyo, 102-0076, Japan
| | - Tomoka Oki
- Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo, 113-8657, Japan
- Japan Science and Technology Agency-Core Research for Evolutional Science and Technology (CREST), Gobancho, Chiyoda, Tokyo, 102-0076, Japan
| | - Ichiro Nishii
- Japan Science and Technology Agency-Core Research for Evolutional Science and Technology (CREST), Gobancho, Chiyoda, Tokyo, 102-0076, Japan
- Department of Biological Science, Nara Women's University, Kitauoya, Higashimachi, Nara, Nara, 630-8506, Japan
| | - Eiichi Mizohata
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Shigeki Matsunaga
- Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo, 113-8657, Japan
- Japan Science and Technology Agency-Core Research for Evolutional Science and Technology (CREST), Gobancho, Chiyoda, Tokyo, 102-0076, Japan
| | - Shigeru Okada
- Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo, 113-8657, Japan.
- Japan Science and Technology Agency-Core Research for Evolutional Science and Technology (CREST), Gobancho, Chiyoda, Tokyo, 102-0076, Japan.
| |
Collapse
|
10
|
Guionet A, Hosseini B, Akiyama H, Hosano H. Medium's conductivity and stage of growth as crucial parameters for efficient hydrocarbon extraction by electric field from colonial micro-algae. Bioelectrochemistry 2018; 123:88-93. [PMID: 29729644 DOI: 10.1016/j.bioelechem.2018.04.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 04/24/2018] [Accepted: 04/24/2018] [Indexed: 10/17/2022]
Abstract
The green algae Botryococcus braunii produces a high amount of extracellular hydrocarbon, making it a promising algae in the field of bio-fuels production. As it mainly produces squalene like hydrocarbons, cosmetic industries are also interested in its milking. Pulsed electric fields (PEF) are an innovative method allowing oil extraction from micro-algae. In common algae accumulating hydrocarbon inside cytoplasm (Chlorella vulgaris, Nannochloropsis sp., etc), electric fields can destroy cell membranes, allowing the release of hydrocarbon. However, for B.braunii, hydrocarbons adhere to the cell wall outside of cells as a matrix. In a previous article we reported that electric fields can unstick cells from a matrix, allowing hydrocarbon harvesting. In this work, we deeper investigated this phenomenon of cell hatching by following 2 parameters: the conductivity of the medium and the cultivation duration of the culture. Cell hatching is accurately evaluated by both microscopic and macroscopic observations. For high conductivity and a short time of cultivation, almost no effect is observed even after up to 1000 PEF pulses are submitted to the cells. While lower conductivity and a longer cultivation period allow strong cell hatching after 200 PEF pulses are applied to the cells. We identify 2 new crucial parameters, able to turn the method from inefficient to very efficient. It might help companies to save energy and money in case of mass production.
Collapse
Affiliation(s)
- Alexis Guionet
- Bioelectrics Department, Institute of Pulsed Power Science, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, Japan.
| | - Bahareh Hosseini
- Graduate School of Science and Technology, Kumamoto University, Japan.
| | - Hidenori Akiyama
- Bioelectrics Department, Institute of Pulsed Power Science, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, Japan; Graduate School of Science and Technology, Kumamoto University, Japan.
| | - Hamid Hosano
- Bioelectrics Department, Institute of Pulsed Power Science, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, Japan; Graduate School of Science and Technology, Kumamoto University, Japan.
| |
Collapse
|
11
|
Nakamura H, Shiozaki T, Gonda N, Furuya K, Matsunaga S, Okada S. Utilization of ammonium by the hydrocarbon-producing microalga, Botryococcus braunii Showa. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.06.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
12
|
Effects of 2-azahypoxanthine on extracellular terpene accumulations by the green microalga Botryococcus braunii, race B. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.10.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
13
|
Furuhashi K, Noguchi T, Okada S, Hasegawa F, Kaizu Y, Imou K. The surface structure of Botryococcus braunii colony prevents the entry of extraction solvents into the colony interior. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.02.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
14
|
Thapa HR, Naik MT, Okada S, Takada K, Molnár I, Xu Y, Devarenne TP. A squalene synthase-like enzyme initiates production of tetraterpenoid hydrocarbons in Botryococcus braunii Race L. Nat Commun 2016; 7:11198. [PMID: 27050299 PMCID: PMC4823828 DOI: 10.1038/ncomms11198] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 02/29/2016] [Indexed: 12/24/2022] Open
Abstract
The green microalga Botryococcus braunii is considered a promising biofuel feedstock producer due to its prodigious accumulation of hydrocarbon oils that can be converted into fuels. B. braunii Race L produces the C40 tetraterpenoid hydrocarbon lycopadiene via an uncharacterized biosynthetic pathway. Structural similarities suggest this pathway follows a biosynthetic mechanism analogous to that of C30 squalene. Confirming this hypothesis, the current study identifies C20 geranylgeranyl diphosphate (GGPP) as a precursor for lycopaoctaene biosynthesis, the first committed intermediate in the production of lycopadiene. Two squalene synthase (SS)-like complementary DNAs are identified in race L with one encoding a true SS and the other encoding an enzyme with lycopaoctaene synthase (LOS) activity. Interestingly, LOS uses alternative C15 and C20 prenyl diphosphate substrates to produce combinatorial hybrid hydrocarbons, but almost exclusively uses GGPP in vivo. This discovery highlights how SS enzyme diversification results in the production of specialized tetraterpenoid oils in race L of B. braunii. The green microalga Botryococcus braunii is a promising biofuel producer due to its ability to produce large amounts of hydrocarbon oils that can be converted into fuels. Here the authors implicate lycopaoctaene synthase, a squalene synthases-like enzyme, in the first step towards the biosynthesis of the C40 tetraterpenoid hydrocarbon lycopadiene.
Collapse
Affiliation(s)
- Hem R Thapa
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, USA
| | - Mandar T Naik
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, USA.,Biomolecular NMR Laboratory, Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, USA
| | - Shigeru Okada
- Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo 113-8657, Japan.,Japan Science and Technology Agency-Core Research for Evolutional Science and Technology (CREST), Gobancho, Chiyoda, Tokyo 102-0076, Japan
| | - Kentaro Takada
- Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo 113-8657, Japan.,Japan Science and Technology Agency-Core Research for Evolutional Science and Technology (CREST), Gobancho, Chiyoda, Tokyo 102-0076, Japan
| | - István Molnár
- Natural Products Center, School of Natural Resources and the Environment, The University of Arizona, Tucson, Arizona 85739, USA
| | - Yuquan Xu
- Natural Products Center, School of Natural Resources and the Environment, The University of Arizona, Tucson, Arizona 85739, USA.,Biotechnology Research Institute, The Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Timothy P Devarenne
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, USA
| |
Collapse
|
15
|
Fang L, Sun D, Xu Z, He J, Qi S, Chen X, Chew W, Liu J. Transcriptomic analysis of a moderately growing subisolate Botryococcus braunii 779 (Chlorophyta) in response to nitrogen deprivation. BIOTECHNOLOGY FOR BIOFUELS 2015; 8:130. [PMID: 26322124 PMCID: PMC4552190 DOI: 10.1186/s13068-015-0307-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Accepted: 08/05/2015] [Indexed: 06/04/2023]
Abstract
BACKGROUND The colonial microalga Botryococcus braunii has been brought to people's attention for its conspicuous ability to accumulate a variety of lipids including hydrocarbons. B. braunii strains are classified into 3 races based on the types of hydrocarbons. A and B races are known to accumulate high level of lipids. However, their extreme slow growth rate has impeded its application for renewable biofuel production. RESULTS In this study, we report the transcriptomic response of a moderately growing subisolate from the culture of Botryococcus sp. CCALA-779 upon nitrogen deprivation (ND). We show that the subisolate has an average growth rate of 0.52 g l(-1) day(-1) under photoautotrophic growth conditions and lipid content is enhanced to 75 % of CDW upon ND. Both rDNA sequence and hydrocarbon composition analyses indicate that the subisolate belongs to A race B. braunii. Hence, it is designated as B. braunii 779. We show that B. braunii 779 transcriptome shares homology to majority of the A race but not B race B. braunii ESTs, suggesting that transcriptomes of A race differ from that of B race. We found that many homologous ESTs between A races 779 and Bot-88 are unknown sequences, implying that A race contains many unknown genes. Pathway-based transcriptomic analysis indicates that energy metabolisms are among the top expressed functions in log-phase cells, indicating that the slow growth rate is a result that energy flow is directed to lipid biosynthesis but not population growth. Upon ND, reconfiguration of metabolisms for reducing power is apparent, suggesting that B. braunii 779 is rapidly adapting under ND condition by transcriptomic reprogramming. CONCLUSIONS Taken together, our result shows that the subisolate B. braunii 779, similar to the Gottingen strain, is useful for biofuel production. Difference between transcriptomes of A and B races implies that different races of B. braunii strains belong to different sub-species. Furthermore, there are many novel genes that are unique to A race, suggesting that sequences of many enzymes involved in hydrocarbon biosynthesis are not currently known. We propose that B. braunii transcriptomes provide a rich source for discovery of novel genes involved in hydrocarbon biosynthesis.
Collapse
Affiliation(s)
- Lei Fang
- />Collaborative Innovation Center of Deep Sea Biology, Ocean College, Zhejiang University, Hangzhou, 310058 Zhejiang China
- />Dalian Ocean University, Dalian, 116023 Liaoning China
| | - Deying Sun
- />Genome Institute of Singapore, A-STAR, Singapore, 138672 Singapore
- />Biopolis Shared Facilities, A-STAR, Singapore, 138671 Singapore
| | - Zhenyu Xu
- />Collaborative Innovation Center of Deep Sea Biology, Ocean College, Zhejiang University, Hangzhou, 310058 Zhejiang China
| | - Jing He
- />Ocean Research Centre of Zhoushan, Zhejiang University, 10 Tiyu Road, Room 502, Zhoushan, 316021 Zhejiang China
| | - Shuyuan Qi
- />Collaborative Innovation Center of Deep Sea Biology, Ocean College, Zhejiang University, Hangzhou, 310058 Zhejiang China
| | - Xin Chen
- />Zhejiang Provincial Key Laboratory for Microbial Biochemistry and Metabolic Engineering and College of Life Sciences, Zhejiang University, Hangzhou, 310058 Zhejiang China
| | - Wee Chew
- />Institute of Chemical and Engineering Sciences, A-STAR, Singapore, 627833 Singapore
| | - Jianhua Liu
- />Collaborative Innovation Center of Deep Sea Biology, Ocean College, Zhejiang University, Hangzhou, 310058 Zhejiang China
- />Ocean Research Centre of Zhoushan, Zhejiang University, 10 Tiyu Road, Room 502, Zhoushan, 316021 Zhejiang China
| |
Collapse
|
16
|
Uchida H, Sumimoto K, Ferriols VME, Imou K, Saga K, Furuhashi K, Matsunaga S, Okada S. Isolation and characterization of two squalene epoxidase genes from Botryococcus braunii, race B. PLoS One 2015; 10:e0122649. [PMID: 25830359 PMCID: PMC4382194 DOI: 10.1371/journal.pone.0122649] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 02/11/2015] [Indexed: 11/19/2022] Open
Abstract
The B race of the green microalga Botryococcus braunii produces triterpene hydrocarbons, botryococcenes and methylsqualenes that can be processed into jet fuels with high heating values. In this alga, squalene is also converted into membrane sterols after 2,3-epoxidation. In the present study, cDNA clones of two distinct squalene epoxidases (BbSQE-I and -II) were isolated. Predicted amino acid sequences encoded on these genes are 45% identical with each other. Introduction of BbSQE-I or -II into Saccharomyces cerevisie erg1 mutants resulted in the complementation of ergosterol auxotrophy. The relative expression level of SQE-II increased 3.5-fold from the early stage to the middle phase of a culture period of 42 days, while that of SQE-I was almost constant throughout the culture period. Southern blot analyses suggested that these genes are single-copied genes. This is the first report on the isolation of functional SQEs that are encoded in duplicated loci in the algal genome.
Collapse
Affiliation(s)
- Hidenobu Uchida
- Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo 113–8657, Japan
- Japan Science and Technology Agency-Core Research for Evolutional Science and Technology (CREST), Gobancho, Chiyoda, Tokyo 102–0076, Japan
| | - Koremitsu Sumimoto
- Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo 113–8657, Japan
- Japan Science and Technology Agency-Core Research for Evolutional Science and Technology (CREST), Gobancho, Chiyoda, Tokyo 102–0076, Japan
| | - Victor Marco Emmanuel Ferriols
- Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo 113–8657, Japan
- Institute of Aquaculture, University of the Philippines Visayas, Miagao, 5023 Iloilo, Philippines
| | - Kenji Imou
- Laboratory of Biological and Mechanical Engineering, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo 113–8657, Japan
| | - Kiyotaka Saga
- Laboratory of Biological and Mechanical Engineering, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo 113–8657, Japan
| | - Kenichi Furuhashi
- Laboratory of Biological and Mechanical Engineering, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo 113–8657, Japan
| | - Shigeki Matsunaga
- Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo 113–8657, Japan
- Japan Science and Technology Agency-Core Research for Evolutional Science and Technology (CREST), Gobancho, Chiyoda, Tokyo 102–0076, Japan
| | - Shigeru Okada
- Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo 113–8657, Japan
- Japan Science and Technology Agency-Core Research for Evolutional Science and Technology (CREST), Gobancho, Chiyoda, Tokyo 102–0076, Japan
| |
Collapse
|
17
|
Bicas JL, Kleinegris DM, Barbosa MJ. Use of methylene blue uptake for assessing cell viability of colony-forming microalgae. ALGAL RES 2015. [DOI: 10.1016/j.algal.2015.02.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
18
|
Bell SA, Niehaus TD, Nybo SE, Chappell J. Structure–Function Mapping of Key Determinants for Hydrocarbon Biosynthesis by Squalene and Squalene Synthase-like Enzymes from the Green Alga Botryococcus braunii Race B. Biochemistry 2014; 53:7570-81. [DOI: 10.1021/bi501264s] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Stephen A. Bell
- Plant
and Soil Sciences, University of Kentucky, Lexington, Kentucky 40546-0312, United States
- Pharmaceutical
Sciences, University of Kentucky, Lexington, Kentucky 40536-0596, United States
| | - Thomas D. Niehaus
- Plant
and Soil Sciences, University of Kentucky, Lexington, Kentucky 40546-0312, United States
| | - S. Eric Nybo
- Plant
and Soil Sciences, University of Kentucky, Lexington, Kentucky 40546-0312, United States
- Pharmaceutical
Sciences, University of Kentucky, Lexington, Kentucky 40536-0596, United States
| | - Joseph Chappell
- Plant
and Soil Sciences, University of Kentucky, Lexington, Kentucky 40546-0312, United States
- Pharmaceutical
Sciences, University of Kentucky, Lexington, Kentucky 40536-0596, United States
| |
Collapse
|
19
|
Khan NE, Myers JA, Tuerk AL, Curtis WR. A process economic assessment of hydrocarbon biofuels production using chemoautotrophic organisms. BIORESOURCE TECHNOLOGY 2014; 172:201-211. [PMID: 25262429 DOI: 10.1016/j.biortech.2014.08.118] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 08/25/2014] [Accepted: 08/26/2014] [Indexed: 06/03/2023]
Abstract
Economic analysis of an ARPA-e Electrofuels (http://arpa-e.energy.gov/?q=arpa-e-programs/electrofuels) process is presented, utilizing metabolically engineered Rhodobacter capsulatus or Ralstonia eutropha to produce the C30+ hydrocarbon fuel, botryococcene, from hydrogen, carbon dioxide, and oxygen. The analysis is based on an Aspen plus® bioreactor model taking into account experimentally determined Rba. capsulatus and Rls. eutropha growth and maintenance requirements, reactor residence time, correlations for gas-liquid mass-transfer coefficient, gas composition, and specific cellular fuel productivity. Based on reactor simulation results encompassing technically relevant parameter ranges, the capital and operating costs of the process were estimated for 5000 bbl-fuel/day plant and used to predict fuel cost. Under the assumptions used in this analysis and crude oil prices, the Levelized Cost of Electricity (LCOE) required for economic feasibility must be less than 2¢/kWh. While not feasible under current market prices and costs, this work identifies key variables impacting process cost and discusses potential alternative paths toward economic feasibility.
Collapse
Affiliation(s)
- Nymul E Khan
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - John A Myers
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Amalie L Tuerk
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Wayne R Curtis
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802, USA.
| |
Collapse
|
20
|
Atobe S, Saga K, Maeyama H, Fujiwara K, Okada S, Imou K. Culture of the green microalga Botryococcus braunii Showa with LED irradiation eliminating violet light enhances hydrocarbon production and recovery. Biosci Biotechnol Biochem 2014; 78:1765-71. [PMID: 25069809 DOI: 10.1080/09168451.2014.932663] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The green microalga Botryococcus braunii (B. braunii), race B, was cultured under light-emitting diode (LED) irradiation with and without violet light. This study examined the effect of violet light on hydrocarbon recovery and production in B. braunii. C34 botryococcene hydrocarbons were efficiently extracted by thermal pretreatments at lower temperatures when the alga was cultured without violet light. The hydrocarbon content was also higher (approximately 3%) in samples cultured without violet light. To elucidate the mechanism of effective hydrocarbon recovery and production, we examined structural components of the extracellular matrix (ECM). The amounts of extracellular carotenoids and water-soluble polymers extracted by thermal pretreatment from the ECM were decreased when the alga was cultured without violet light. These results indicate that LED irradiation without violet light is more effective for hydrocarbon recovery and production in B. braunii. Furthermore, structural ECM components are closely involved in hydrocarbon recovery and production in B. braunii.
Collapse
Affiliation(s)
- Sueko Atobe
- a Graduate School of Agricultural and Life Sciences, The University of Tokyo , Tokyo , Japan
| | | | | | | | | | | |
Collapse
|
21
|
Kim HS, Weiss TL, Thapa HR, Devarenne TP, Han A. A microfluidic photobioreactor array demonstrating high-throughput screening for microalgal oil production. LAB ON A CHIP 2014; 14:1415-25. [PMID: 24496295 DOI: 10.1039/c3lc51396c] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Microalgae are envisioned as a future source of renewable oil. The feasibility of producing high-value biomolecules from microalgae is strongly dependent on developing strains with increased productivity and environmental tolerance, understanding algal gene regulation, and optimizing growth conditions for higher production of target molecules. We present a high-throughput microfluidic microalgal photobioreactor array capable of applying 64 different light conditions to arrays of microscale algal photobioreactors and apply this device to investigate how light conditions influence algal growth and oil production. Using the green colony-forming microalga Botryococcus braunii, the light intensity and light-dark cycle conditions were identified that induced 1.8-fold higher oil accumulation over the typically used culture conditions. Additionally, the studies revealed that the condition under which maximum oil production occurs is significantly different from that of maximum growth. This screening test was accomplished using the developed photobioreactor array at 250 times higher throughput compared to conventional flask-scale photobioreactors.
Collapse
Affiliation(s)
- Hyun Soo Kim
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, USA.
| | | | | | | | | |
Collapse
|
22
|
Arbib Z, Ruiz J, Álvarez-Díaz P, Garrido-Pérez C, Perales JA. Capability of different microalgae species for phytoremediation processes: wastewater tertiary treatment, CO2 bio-fixation and low cost biofuels production. WATER RESEARCH 2014; 49:465-74. [PMID: 24268718 DOI: 10.1016/j.watres.2013.10.036] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 10/10/2013] [Accepted: 10/13/2013] [Indexed: 05/06/2023]
Abstract
Scenedesmus obliquus, Chlorella vulgaris, Chlorella kessleri and a natural Bloom were cultivated in batch experiments, under controlled conditions, in urban wastewater (WW) and synthetic wastewater (SW) under 5% CO2 in air, with the object of estimating their capacity for nutrient removal, carbon dioxide biofixation, and generation of valuable biomass. In both culture media, the Bloom (Bl) and Scenedesmus (Sc) showed higher final biomass concentration (dried weight, dw) than the other species; the maximum yield obtained was 1950 ± 243 mg L(-1) for Bl and the minimum 821 ± 88 mg L(-1) for Cv, both in synthetic wastewater. Maximum specific growth rate values do not show significant differences between any of the 4 strains tested (p ≤ 0.05), nor between the 2 culture media. A new homogeneous method of calculating productivities has been proposed. Nitrogen removal in all the reactors was higher than 90%, except for BlSW (79%), and for phosphorus, the removal was higher than 98% in all trials. Maximum CO2 consumption rates reached were 424.4 and 436.7 mg L(-1) d(-1) for ScSW and ScWW respectively.
Collapse
Affiliation(s)
- Zouhayr Arbib
- Department of Environmental Technologies, Centro Andaluz de Ciencia y Tecnología Marinas (CACYTMAR), Campus de Excelencia Internacional del Mar (CEIMAR), Campus Universitario de Puerto Real, University of Cádiz, 11510 Puerto Real, Cádiz, Spain; Aqualia Gestion Integral del Agua SA, Spain.
| | - Jesús Ruiz
- Department of Environmental Technologies, Centro Andaluz de Ciencia y Tecnología Marinas (CACYTMAR), Campus de Excelencia Internacional del Mar (CEIMAR), Campus Universitario de Puerto Real, University of Cádiz, 11510 Puerto Real, Cádiz, Spain
| | - Pablo Álvarez-Díaz
- Department of Environmental Technologies, Centro Andaluz de Ciencia y Tecnología Marinas (CACYTMAR), Campus de Excelencia Internacional del Mar (CEIMAR), Campus Universitario de Puerto Real, University of Cádiz, 11510 Puerto Real, Cádiz, Spain
| | - Carmen Garrido-Pérez
- Department of Environmental Technologies, Centro Andaluz de Ciencia y Tecnología Marinas (CACYTMAR), Campus de Excelencia Internacional del Mar (CEIMAR), Campus Universitario de Puerto Real, University of Cádiz, 11510 Puerto Real, Cádiz, Spain
| | - José A Perales
- Department of Environmental Technologies, Centro Andaluz de Ciencia y Tecnología Marinas (CACYTMAR), Campus de Excelencia Internacional del Mar (CEIMAR), Campus Universitario de Puerto Real, University of Cádiz, 11510 Puerto Real, Cádiz, Spain
| |
Collapse
|
23
|
Liu CI, Jeng WY, Chang WJ, Shih MF, Ko TP, Wang AHJ. Structural insights into the catalytic mechanism of human squalene synthase. ACTA ACUST UNITED AC 2014; 70:231-41. [PMID: 24531458 DOI: 10.1107/s1399004713026230] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 09/23/2013] [Indexed: 11/11/2022]
Abstract
Squalene synthase (SQS) is a divalent metal-ion-dependent enzyme that catalyzes the two-step reductive `head-to-head' condensation of two molecules of farnesyl pyrophosphate to form squalene using presqualene diphosphate (PSPP) as an intermediate. In this paper, the structures of human SQS and its mutants in complex with several substrate analogues and intermediates coordinated with Mg2+ or Mn2+ are presented, which stepwise delineate the biosynthetic pathway. Extensive study of the SQS active site has identified several critical residues that are involved in binding reduced nicotinamide dinucleotide phosphate (NADPH). Based on mutagenesis data and a locally closed (JK loop-in) structure observed in the hSQS-(F288L)-PSPP complex, an NADPH-binding model is proposed for SQS. The results identified four major steps (substrate binding, condensation, intermediate formation and translocation) of the ordered sequential mechanisms involved in the `1'-1' isoprenoid biosynthetic pathway. These new findings clarify previous hypotheses based on site-directed mutagenesis and biochemical analysis.
Collapse
Affiliation(s)
- Chia-I Liu
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Wen-Yih Jeng
- University Center for Bioscience and Biotechnology, National Cheng Kung University, Tainan 70101, Taiwan
| | - Wei-Jung Chang
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Min-Fang Shih
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Tzu-Ping Ko
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Andrew H-J Wang
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| |
Collapse
|
24
|
Suzuki R, Ito N, Uno Y, Nishii I, Kagiwada S, Okada S, Noguchi T. Transformation of lipid bodies related to hydrocarbon accumulation in a green alga, Botryococcus braunii (Race B). PLoS One 2013; 8:e81626. [PMID: 24339948 PMCID: PMC3855424 DOI: 10.1371/journal.pone.0081626] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 10/23/2013] [Indexed: 12/27/2022] Open
Abstract
The colonial microalga Botryococcus braunii accumulates large quantities of hydrocarbons mainly in the extracellular space; most other oleaginous microalgae store lipids in the cytoplasm. Botryococcus braunii is classified into three principal races (A, B, and L) based on the types of hydrocarbons. Race B has attracted the most attention as an alternative to petroleum by its higher hydrocarbon contents than the other races and its hydrocarbon components, botryococcenes and methylsqualenes, both can be readily converted into biofuels. We studied race B using fluorescence and electron microscopy, and clarify the stage when extracellular hydrocarbon accumulation occurs during the cell cycle, in a correlation with the behavior and structural changes of the lipid bodies and discussed development of the algal colony. New accumulation of lipids on the cell surface occurred after cell division in the basolateral region of daughter cells. While lipid bodies were observed throughout the cell cycle, their size and inclusions were dynamically changing. When cells began dividing, the lipid bodies increased in size and inclusions until the extracellular accumulation of lipids started. Most of the lipids disappeared from the cytoplasm concomitant with the extracellular accumulation, and then reformed. We therefore hypothesize that lipid bodies produced during the growth of B. braunii are related to lipid secretion. New lipids secreted at the cell surface formed layers of oil droplets, to a maximum depth of six layers, and fused to form flattened, continuous sheets. The sheets that combined a pair of daughter cells remained during successive cellular divisions and the colony increased in size with increasing number of cells.
Collapse
Affiliation(s)
- Reiko Suzuki
- Department of Biological Sciences, Nara Women's University, Nara, Nara, Japan
- Japan Science and Technology Agency-CREST, Chiyoda, Tokyo, Japan
| | - Naoko Ito
- Department of Biological Sciences, Nara Women's University, Nara, Nara, Japan
| | - Yuki Uno
- Department of Biological Sciences, Nara Women's University, Nara, Nara, Japan
| | - Ichiro Nishii
- Temasek Life Sciences Laboratory, Singapore, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- Japan Science and Technology Agency-CREST, Chiyoda, Tokyo, Japan
| | - Satoshi Kagiwada
- Department of Biological Sciences, Nara Women's University, Nara, Nara, Japan
- Japan Science and Technology Agency-CREST, Chiyoda, Tokyo, Japan
| | - Sigeru Okada
- Department of Aquatic Biosciences, the University of Tokyo, Bunkyo, Tokyo, Japan
- Japan Science and Technology Agency-CREST, Chiyoda, Tokyo, Japan
| | - Tetsuko Noguchi
- Department of Biological Sciences, Nara Women's University, Nara, Nara, Japan
- Japan Science and Technology Agency-CREST, Chiyoda, Tokyo, Japan
- * E-mail:
| |
Collapse
|
25
|
Khatri W, Hendrix R, Niehaus T, Chappell J, Curtis WR. Hydrocarbon production in high density Botryococcus braunii race B continuous culture. Biotechnol Bioeng 2013; 111:493-503. [PMID: 24122424 DOI: 10.1002/bit.25126] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2013] [Revised: 09/20/2013] [Accepted: 10/02/2013] [Indexed: 11/05/2022]
Abstract
Continuous cultures of Botryococcus braunii race B were maintained at photosynthetic cell densities as high as 20 g dry weight per liter for up to 3 months. Growth associated triterpene hydrocarbon accumulation was nearly constant at 22.5% of dry weight for a range of growth rates maintained by daily replacement of 5-15% of the respective cultures. The ability to achieve high cell concentrations and oil levels of roughly 5 g triterpene oil/L resulted from a combination of high light (∼ 1/4 full sun for 15 h/day) and replenishing stoichiometrically balanced growth medium. Due to light-limited growth conditions, cell concentration dropped nearly linearly with increased dilution rate. This reduction in cell number resulted in increased productivity per cell at higher dilution rates and was accompanied by a dramatic increase in algae colony size from 0.09 to 0.343 mm at high dilution rate. This change in colony size resulted in an equally dramatic change in optical density (OD) per gram dry weight, which precluded use of simple correlations of OD and cell concentration. A trickle-film photobioreactor was also demonstrated as a scalable approach to achieving these ultra-high cell concentrations. Additional media analysis revealed a steady increase in photobioreactor conductivity suggesting an accumulation of ions may be the reason for rapid culture crash and washout observed at all dilution rates after several months of continuous operation. The volumetric productivity of 22.5 mg oil/L/photo-h reported here is more than an order of magnitude higher than previous reports for B. braunii race B, reflecting the high cell densities used in this work and substantiating a higher metabolic rate for B. braunii race B than previously surmised from its relatively long doubling times.
Collapse
Affiliation(s)
- Waqas Khatri
- Department of Chemical Engineering, Penn State University, University Park, Pennsylvania, 16802
| | | | | | | | | |
Collapse
|
26
|
Active hydrocarbon biosynthesis and accumulation in a green alga, Botryococcus braunii (race A). EUKARYOTIC CELL 2013; 12:1132-41. [PMID: 23794509 DOI: 10.1128/ec.00088-13] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Among oleaginous microalgae, the colonial green alga Botryococcus braunii accumulates especially large quantities of hydrocarbons. This accumulation may be achieved more by storage of lipids in the extracellular space rather than in the cytoplasm, as is the case for all other examined oleaginous microalgae. The stage of hydrocarbon synthesis during the cell cycle was determined by autoradiography. The cell cycle of B. braunii race A was synchronized by aminouracil treatment, and cells were taken at various stages in the cell cycle and cultured in a medium containing [(14)C]acetate. Incorporation of (14)C into hydrocarbons was detected. The highest labeling occurred just after septum formation, when it was about 2.6 times the rate during interphase. Fluorescent and electron microscopy revealed that new lipid accumulation on the cell surface occurred during at least two different growth stages and sites of cells. Lipid bodies in the cytoplasm were not prominent in interphase cells. These lipid bodies then increased in number, size, and inclusions, reaching maximum values just before the first lipid accumulation on the cell surface at the cell apex. Most of them disappeared from the cytoplasm concomitant with the second new accumulation at the basolateral region, where extracellular lipids continuously accumulated. The rough endoplasmic reticulum near the plasma membrane is prominent in B. braunii, and the endoplasmic reticulum was often in contact with both a chloroplast and lipid bodies in cells with increasing numbers of lipid bodies. We discuss the transport pathway of precursors of extracellular hydrocarbons in race A.
Collapse
|
27
|
Molnár I, Lopez D, Wisecaver JH, Devarenne TP, Weiss TL, Pellegrini M, Hackett JD. Bio-crude transcriptomics: gene discovery and metabolic network reconstruction for the biosynthesis of the terpenome of the hydrocarbon oil-producing green alga, Botryococcus braunii race B (Showa). BMC Genomics 2012; 13:576. [PMID: 23110428 PMCID: PMC3533583 DOI: 10.1186/1471-2164-13-576] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 10/19/2012] [Indexed: 12/16/2022] Open
Abstract
Background Microalgae hold promise for yielding a biofuel feedstock that is sustainable, carbon-neutral, distributed, and only minimally disruptive for the production of food and feed by traditional agriculture. Amongst oleaginous eukaryotic algae, the B race of Botryococcus braunii is unique in that it produces large amounts of liquid hydrocarbons of terpenoid origin. These are comparable to fossil crude oil, and are sequestered outside the cells in a communal extracellular polymeric matrix material. Biosynthetic engineering of terpenoid bio-crude production requires identification of genes and reconstruction of metabolic pathways responsible for production of both hydrocarbons and other metabolites of the alga that compete for photosynthetic carbon and energy. Results A de novo assembly of 1,334,609 next-generation pyrosequencing reads form the Showa strain of the B race of B. braunii yielded a transcriptomic database of 46,422 contigs with an average length of 756 bp. Contigs were annotated with pathway, ontology, and protein domain identifiers. Manual curation allowed the reconstruction of pathways that produce terpenoid liquid hydrocarbons from primary metabolites, and pathways that divert photosynthetic carbon into tetraterpenoid carotenoids, diterpenoids, and the prenyl chains of meroterpenoid quinones and chlorophyll. Inventories of machine-assembled contigs are also presented for reconstructed pathways for the biosynthesis of competing storage compounds including triacylglycerol and starch. Regeneration of S-adenosylmethionine, and the extracellular localization of the hydrocarbon oils by active transport and possibly autophagy are also investigated. Conclusions The construction of an annotated transcriptomic database, publicly available in a web-based data depository and annotation tool, provides a foundation for metabolic pathway and network reconstruction, and facilitates further omics studies in the absence of a genome sequence for the Showa strain of B. braunii, race B. Further, the transcriptome database empowers future biosynthetic engineering approaches for strain improvement and the transfer of desirable traits to heterologous hosts.
Collapse
Affiliation(s)
- István Molnár
- Natural Products Center, School of Natural Resources and the Environment, The University of Arizona, Tucson, 85739, USA.
| | | | | | | | | | | | | |
Collapse
|
28
|
Colony organization in the green alga Botryococcus braunii (Race B) is specified by a complex extracellular matrix. EUKARYOTIC CELL 2012; 11:1424-40. [PMID: 22941913 DOI: 10.1128/ec.00184-12] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Botryococcus braunii is a colonial green alga whose cells associate via a complex extracellular matrix (ECM) and produce prodigious amounts of liquid hydrocarbons that can be readily converted into conventional combustion engine fuels. We used quick-freeze deep-etch electron microscopy and biochemical/histochemical analysis to elucidate many new features of B. braunii cell/colony organization and composition. Intracellular lipid bodies associate with the chloroplast and endoplasmic reticulum (ER) but show no evidence of being secreted. The ER displays striking fenestrations and forms a continuous subcortical system in direct contact with the cell membrane. The ECM has three distinct components. (i) Each cell is surrounded by a fibrous β-1, 4- and/or β-1, 3-glucan-containing cell wall. (ii) The intracolonial ECM space is filled with a cross-linked hydrocarbon network permeated with liquid hydrocarbons. (iii) Colonies are enclosed in a retaining wall festooned with a fibrillar sheath dominated by arabinose-galactose polysaccharides, which sequesters ECM liquid hydrocarbons. Each cell apex associates with the retaining wall and contributes to its synthesis. Retaining-wall domains also form "drapes" between cells, with some folding in on themselves and penetrating the hydrocarbon interior of a mother colony, partitioning it into daughter colonies. We propose that retaining-wall components are synthesized in the apical Golgi apparatus, delivered to apical ER fenestrations, and assembled on the surfaces of apical cell walls, where a proteinaceous granular layer apparently participates in fibril morphogenesis. We further propose that hydrocarbons are produced by the nonapical ER, directly delivered to the contiguous cell membrane, and pass across the nonapical cell wall into the hydrocarbon-based ECM.
Collapse
|
29
|
Arbib Z, Ruiz J, Alvarez P, Garrido C, Barragan J, Perales JA. Chlorella stigmatophora for urban wastewater nutrient removal and CO2 abatement. INTERNATIONAL JOURNAL OF PHYTOREMEDIATION 2012; 14:714-725. [PMID: 22908639 DOI: 10.1080/15226514.2011.619237] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Batch experiments were performed to study biomass growth rate, nutrient removal and carbon dioxide bio-fixation of the marine microalgae Chlorella stigmatophora. Four different cultures at different salinities were tested: wastewater (WW), synthetic wastewater (SWW), seawater (SW) and diluted seawater (DSW). Experimental results showed that Chlorella stigmatophora grew satisfactorily in all culture media, except in SWW where inhibition occurred. In all cases, biomass experimental data were fitted to the Verlhust Logistic model (R2 > 0.982, p < or = 0.05). Maximum biomass productivity (P(bmax)) and CO2 biofixation (P(vCO2)) were reached in the WW medium, 1.146g SSL(-1)day(-1) and 2.324g CO2L(-1)day(-1) respectively. The order of maximum specific growth rates (micro max) was WW >DSW>SW. In order to compare nitrogen and phosphorous removal kinetics, an estimation of the time required to reach the most restrictive concentration of total N and P in effluents as defined in the Directive 98/1565/CE (10 mg sigmaNL(-1) (T10(N)) and 1 mg sigmaPL(-1) (T1(p)) was performed. In the WW test T10(N) and T1(p) needed were of 45.15 and 32.27 hours respectively and at the end of the experimental the removal was in both 100%.
Collapse
Affiliation(s)
- Zouhayr Arbib
- Department of Environmental Technologies, Centro Andaluz de Ciencia y Tecnología Marinas (CACYTMAR), Campus Universitario de Puerto Real, University of Cadiz, Cadiz, Spain.
| | | | | | | | | | | |
Collapse
|
30
|
Micronutrient requirements for growth and hydrocarbon production in the oil producing green alga Botryococcus braunii (Chlorophyta). PLoS One 2012; 7:e41459. [PMID: 22848502 PMCID: PMC3405085 DOI: 10.1371/journal.pone.0041459] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2012] [Accepted: 06/25/2012] [Indexed: 11/19/2022] Open
Abstract
The requirements of micronutrients for biomass and hydrocarbon production in Botryococcus braunii UTEX 572 were studied using response surface methodology. The concentrations of four micronutrients (iron, manganese, molybdenum, and nickel) were manipulated to achieve the best performance of B. braunii in laboratory conditions. The responses of algal biomass and hydrocarbon to the concentration variations of the four micronutrients were estimated by a second order quadratic regression model. Genetic algorithm calculations showed that the optimal level of micronutrients for algal biomass were 0.266 µM iron, 0.707 µM manganese, 0.624 µM molybdenum and 3.38 µM nickel. The maximum hydrocarbon content could be achieved when the culture media contained 10.43 µM iron, 6.53 µM manganese, 0.012 µM molybdenum and 1.73 µM nickel. The validation through an independent test in a photobioreactor suggests that the modified media with optimised concentrations of trace elements can increase algal biomass by 34.5% and hydrocarbon by 27.4%. This study indicates that micronutrients play significant roles in regulating algal growth and hydrocarbon production, and the response surface methodology can be used to optimise the composition of culture medium in algal culture.
Collapse
|
31
|
Matsushima D, Jenke-Kodama H, Sato Y, Fukunaga Y, Sumimoto K, Kuzuyama T, Matsunaga S, Okada S. The single cellular green microalga Botryococcus braunii, race B possesses three distinct 1-deoxy-D-xylulose 5-phosphate synthases. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2012; 185-186:309-320. [PMID: 22325894 DOI: 10.1016/j.plantsci.2012.01.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 12/29/2011] [Accepted: 01/04/2012] [Indexed: 05/31/2023]
Abstract
Green algae exclusively use the methylerythritol 4-phosphate (MEP) pathway for the biosynthesis of isoprenoids. The first enzyme of this pathway is 1-deoxy-D-xylulose 5-phosphate synthase (DXS, EC 2.2.1.7). Green algae have been thought to possess only a single DXS, in contrast to land plants, which have at least two isoforms that serve different roles in metabolism. The green microalga Botryococcus braunii has an extraordinary isoprenoid metabolism, as it produces large amounts of triterpene hydrocarbons. Here, we did cDNA cloning of DXSs from B. braunii and examined enzyme activities of the heterologously expressed proteins. Three distinct DXS isoforms were identified, all of which were functional and had similar kinetic properties, whereas the temperature dependence of enzyme activity showed considerable differences. Transcription of the genes was examined by real time quantitative RT-PCR. The three DXS genes were simultaneously expressed, and the expression levels were highest on day six after subculturing. B. braunii is the first green microalga demonstrated to have multiple DXS isoforms like land plants. This difference to other microalgae seems to mirror its special needs for extensive triterpene production by increasing the metabolic flow through the MEP pathway.
Collapse
Affiliation(s)
- Daisuke Matsushima
- Department of Aquatic Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo, Tokyo 113-8657, Japan
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Spanova M, Daum G. Squalene - biochemistry, molecular biology, process biotechnology, and applications. EUR J LIPID SCI TECH 2011. [DOI: 10.1002/ejlt.201100203] [Citation(s) in RCA: 155] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
33
|
Eroglu E, Okada S, Melis A. Hydrocarbon productivities in different Botryococcus strains: comparative methods in product quantification. JOURNAL OF APPLIED PHYCOLOGY 2011; 23:763-775. [PMID: 21909190 PMCID: PMC3143338 DOI: 10.1007/s10811-010-9577-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2010] [Revised: 08/13/2010] [Accepted: 08/13/2010] [Indexed: 05/03/2023]
Abstract
Six different strains of the green microalgae Botryococcus belonging to the A-race or B-race, accumulating alkadiene or botryococcene hydrocarbons, respectively, were compared for biomass and hydrocarbon productivities. Biomass productivity was assessed gravimetrically upon strain growth in the laboratory under defined conditions. Hydrocarbon productivities were measured by three different and independent experimental approaches, including density equilibrium of the intact cells and micro-colonies, spectrophotometric analysis of hydrocarbon extracts, and gravimetric quantitation of eluted hydrocarbons. All three hydrocarbon-quantitation methods yielded similar results for each of the strains examined. The B-race microalgae Botryococcus braunii var. Showa and Kawaguchi-1 constitutively accumulated botryococcene hydrocarbons equivalent to 30% and 20%, respectively, of their overall biomass. The A-race microalgae Botryococcus braunii, varieties Yamanaka, UTEX 2441 and UTEX LB572 constitutively accumulated alkadiene hydrocarbons ranging from 14% to 13% and 10% of their overall biomass, respectively. Botryococcus sudeticus (UTEX 2629), a morphologically different green microalga, had the lowest hydrocarbon accumulation, equal to about 3% of its overall biomass. Results validate the density equilibrium and spectrophotometric analysis methods in the quantitation of botryococcene-type hydrocarbons. These analytical advances will serve in the screening and selection of B. braunii and of other microalgae in efforts to identify those having a high hydrocarbon content for use in commercial applications.
Collapse
Affiliation(s)
- Ela Eroglu
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3102 USA
| | - Shigeru Okada
- Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113 -8657 Japan
| | - Anastasios Melis
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3102 USA
| |
Collapse
|
34
|
Weiss TL, Chun HJ, Okada S, Vitha S, Holzenburg A, Laane J, Devarenne TP. Raman spectroscopy analysis of botryococcene hydrocarbons from the green microalga Botryococcus braunii. J Biol Chem 2010; 285:32458-66. [PMID: 20705610 DOI: 10.1074/jbc.m110.157230] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Botryococcus braunii, B race is a unique green microalga that produces large amounts of liquid hydrocarbons known as botryococcenes that can be used as a fuel for internal combustion engines. The simplest botryococcene (C(30)) is metabolized by methylation to give intermediates of C(31), C(32), C(33), and C(34), with C(34) being the predominant botryococcene in some strains. In the present work we have used Raman spectroscopy to characterize the structure of botryococcenes in an attempt to identify and localize botryococcenes within B. braunii cells. The spectral region from 1600-1700 cm(-1) showed ν(C=C) stretching bands specific for botryococcenes. Distinct botryococcene Raman bands at 1640 and 1647 cm(-1) were assigned to the stretching of the C=C bond in the botryococcene branch and the exomethylene C=C bonds produced by the methylations, respectively. A Raman band at 1670 cm(-1) was assigned to the backbone C=C bond stretching. Density function theory calculations were used to determine the Raman spectra of all botryococcenes to compare computed theoretical values with those observed. The analysis showed that the ν(C=C) stretching bands at 1647 and 1670 cm(-1) are actually composed of several closely spaced bands arising from the six individual C=C bonds in the molecule. We also used confocal Raman microspectroscopy to map the presence and location of methylated botryococcenes within a colony of B. braunii cells based on the methylation-specific 1647 cm(-1) botryococcene Raman shift.
Collapse
Affiliation(s)
- Taylor L Weiss
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843-2128, USA
| | | | | | | | | | | | | |
Collapse
|
35
|
|
36
|
Eroglu E, Melis A. “Density equilibrium” method for the quantitative and rapid in situ determination of lipid, hydrocarbon, or biopolymer content in microorganisms. Biotechnol Bioeng 2009; 102:1406-15. [DOI: 10.1002/bit.22182] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
37
|
Hodaifa G, Martínez MAE, Sánchez S. Use of industrial wastewater from olive-oil extraction for biomass production of Scenedesmus obliquus. BIORESOURCE TECHNOLOGY 2008; 99:1111-7. [PMID: 17434730 DOI: 10.1016/j.biortech.2007.02.020] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2006] [Revised: 02/20/2007] [Accepted: 02/20/2007] [Indexed: 05/14/2023]
Abstract
The use of rinse water (RW) from two-phase centrifugation in the olive-oil extraction industry has been studied in relation to the production of the microalga Scenedesmus obliquus (CCAP 276/3A). The characterization of the wastewater indicates that it is N deficient. The highest value of maximum specific growth rate, 0.044 h(-1) was registered in the culture with 5% RW. However, biomass productivity proved greater in the culture with 100% RW. The specific growth rates were adjusted to a model of inhibition by substrate. The content in normalized chlorophyll diminished with the duration of the cultures, reaching a minimum CHL'(min) value, which showed an inhibition type similar to that of the specific growth rate. The yield in protein indicates that the cultures were limited by N to approximately 50% RW. The greater specific rate of protein synthesis during the exponential phase was 3.7 mg/gh to 50% RW. It was found that the composition of the lipid fraction of the biomass depended on the percentage of wastewater used as the nutrient medium, reaching the highest percentages of monounsaturated, polyunsaturated, and essential fatty acids in the culture with 100% RW.
Collapse
Affiliation(s)
- Gassan Hodaifa
- Complutense University of Madrid, Faculty of Chemical Science, Chemical Engineering, Ciudad Universitaria, s/n, 28040 Madrid, Spain.
| | | | | |
Collapse
|
38
|
Abstract
Isoprenoids represent the oldest class of known low molecular-mass natural products synthesized by plants. Their biogenesis in plastids, mitochondria and the endoplasmic reticulum-cytosol proceed invariably from the C5 building blocks, isopentenyl diphosphate and/or dimethylallyl diphosphate according to complex and reiterated mechanisms. Compounds derived from the pathway exhibit a diverse spectrum of biological functions. This review centers on advances obtained in the field based on combined use of biochemical, molecular biology and genetic approaches. The function and evolutionary implications of this metabolism are discussed in relation with seminal informations gathered from distantly but related organisms.
Collapse
Affiliation(s)
- Florence Bouvier
- Institut de Biologie Moléculaire des Plantes du CNRS (UPR2357) et Université Louis Pasteur, 12 rue du Général Zimmer, 67084 Strasbourg Cedex, France
| | | | | |
Collapse
|
39
|
Metzger P, Largeau C. Botryococcus braunii: a rich source for hydrocarbons and related ether lipids. Appl Microbiol Biotechnol 2004; 66:486-96. [PMID: 15630516 DOI: 10.1007/s00253-004-1779-z] [Citation(s) in RCA: 247] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2004] [Revised: 09/23/2004] [Accepted: 09/24/2004] [Indexed: 12/01/2022]
Abstract
This paper presents a review on Botryococcus braunii, a cosmopolitan green colonial microalga characterised by a considerable production of lipids, notably hydrocarbons. Strains like wild populations of this alga differ in the type of hydrocarbons they synthesise and accumulate: (1) n-alkadienes and trienes, (2) triterpenoid botryococcenes and methylated squalenes, or (3) a tetraterpenoid, lycopadiene. In addition to hydrocarbons and some classic lipids, these algae produce numerous series of characteristic ether lipids closely related to hydrocarbons. This review covers the algal biodiversity, the chemical structures and biosynthesis of hydrocarbons and ether lipids and the biotechnological studies related to hydrocarbon production.
Collapse
Affiliation(s)
- P Metzger
- Laboratoire de Chimie Bioorganique et Organique Physique, Ecole Nationale Supérieure de Chimie de Paris, 11 Rue Pierre et Marie Curie, 75231 cedex 05 Paris, France.
| | | |
Collapse
|
40
|
Achitouv E, Metzger P, Rager MN, Largeau C. C31-C34 methylated squalenes from a Bolivian strain of Botryococcus braunii. PHYTOCHEMISTRY 2004; 65:3159-3165. [PMID: 15541746 DOI: 10.1016/j.phytochem.2004.09.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2004] [Revised: 09/09/2004] [Indexed: 05/24/2023]
Abstract
Three new triterpenes, synthesized by a Bolivian strain of the green microalga Botryococcus braunii, were isolated and their chemical structures determined by 1D and 2D NMR, and mass spectrometry. These compounds are tri-, di-, and mono-methylsqualenes, co-occurring with the previously identified tetramethylsqualene and some C(30)-C(32) botryococcenes. In this strain, methylated squalenes constitute up to 24% of the total hydrocarbons and 4.5% of the dry biomass. The results of a pulse-chase experiment with L-[Me-(13)C] methionine provide evidence for the origin of these compounds via methylation of squalene at positions 3, 7, 18 and 22.
Collapse
Affiliation(s)
- Etienne Achitouv
- Laboratoire de Chimie Bioorganique et Organique Physique, Universite Pierre et Marie Curie, Ecole Nationale Supérieure de Chimie de Paris, UMR CNRS 7573, ENSCP, 11 Rue P. et M. Curie, 75231 Paris cedex 05, France
| | | | | | | |
Collapse
|