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202
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Kirst H, Formighieri C, Melis A. Maximizing photosynthetic efficiency and culture productivity in cyanobacteria upon minimizing the phycobilisome light-harvesting antenna size. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1653-64. [PMID: 25046143 DOI: 10.1016/j.bbabio.2014.07.009] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 07/03/2014] [Accepted: 07/10/2014] [Indexed: 12/25/2022]
Abstract
A phycocyanin-deletion mutant of Synechocystis (cyanobacteria) was generated upon replacement of the CPC-operon with a kanamycin resistance cassette. The Δcpc transformant strains (Δcpc) exhibited a green phenotype, compared to the blue-green of the wild type (WT), lacked the distinct phycocyanin absorbance at 625nm, and had a lower Chl per cell content and a lower PSI/PSII reaction center ratio compared to the WT. Molecular and genetic analyses showed replacement of all WT copies of the Synechocystis DNA with the transgenic version, thereby achieving genomic DNA homoplasmy. Biochemical analyses showed the absence of the phycocyanin α- and β-subunits, and the overexpression of the kanamycin resistance NPTI protein in the Δcpc. Physiological analyses revealed a higher, by a factor of about 2, intensity for the saturation of photosynthesis in the Δcpc compared to the WT. Under limiting intensities of illumination, growth of the Δcpc was slower than that of the WT. This difference in the rate of cell duplication diminished gradually as growth irradiance increased. Identical rates of cell duplication of about 13h for both WT and Δcpc were observed at about 800μmolphotonsm(-2)s(-1) or greater. Culture productivity analyses under simulated bright sunlight and high cell-density conditions showed that biomass accumulation by the Δcpc was 1.57-times greater than that achieved by the WT. Thus, the work provides first-time direct evidence of the applicability of the Truncated Light-harvesting Antenna (TLA)-concept in cyanobacteria, entailing substantial improvements in the photosynthetic efficiency and productivity of mass cultures upon minimizing the phycobilisome light-harvesting antenna size.
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Affiliation(s)
- Henning Kirst
- Department of Plant & Microbial Biology, University of California, Berkeley, CA 94720-3102, USA
| | - Cinzia Formighieri
- Department of Plant & Microbial Biology, University of California, Berkeley, CA 94720-3102, USA
| | - Anastasios Melis
- Department of Plant & Microbial Biology, University of California, Berkeley, CA 94720-3102, USA.
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203
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Cole AJ, de Nys R, Paul NA. Removing constraints on the biomass production of freshwater macroalgae by manipulating water exchange to manage nutrient flux. PLoS One 2014; 9:e101284. [PMID: 25000501 PMCID: PMC4085068 DOI: 10.1371/journal.pone.0101284] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 06/04/2014] [Indexed: 11/19/2022] Open
Abstract
Freshwater macroalgae represent a largely overlooked group of phototrophic organisms that could play an important role within an industrial ecology context in both utilising waste nutrients and water and supplying biomass for animal feeds and renewable chemicals and fuels. This study used water from the intensive aquaculture of freshwater fish (Barramundi) to examine how the biomass production rate and protein content of the freshwater macroalga Oedogonium responds to increasing the flux of nutrients and carbon, by either increasing water exchange rates or through the addition of supplementary nitrogen and CO2. Biomass production rates were highest at low flow rates (0.1–1 vol.day−1) using raw pond water. The addition of CO2 to cultures increased biomass production rates by between 2 and 25% with this effect strongest at low water exchange rates. Paradoxically, the addition of nitrogen to cultures decreased productivity, especially at low water exchange rates. The optimal culture of Oedogonium occurred at flow rates of between 0.5–1 vol.day−1, where uptake rates peaked at 1.09 g.m−2.day−1 for nitrogen and 0.13 g.m−2.day−1 for phosphorous. At these flow rates Oedogonium biomass had uptake efficiencies of 75.2% for nitrogen and 22.1% for phosphorous. In this study a nitrogen flux of 1.45 g.m−2.day−1 and a phosphorous flux of 0.6 g.m−2.day−1 was the minimum required to maintain the growth of Oedogonium at 16–17 g DW.m−2.day−1 and a crude protein content of 25%. A simple model of minimum inputs shows that for every gram of dry weight biomass production (g DW.m−2.day−1), Oedogonium requires 0.09 g.m−2.day−1 of nitrogen and 0.04 g.m−2.day−1 of phosphorous to maintain growth without nutrient limitation whilst simultaneously maintaining a high-nutrient uptake rate and efficiency. As such the integrated culture of freshwater macroalgae with aquaculture for the purposes of nutrient recovery is a feasible solution for the bioremediation of wastewater and the supply of a protein resource.
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Affiliation(s)
- Andrew J. Cole
- MACRO — the Centre for Macroalgal Resources and Biotechnology, and School of Marine and Tropical Biology, James Cook University, Townsville, Queensland, Australia
- * E-mail:
| | - Rocky de Nys
- MACRO — the Centre for Macroalgal Resources and Biotechnology, and School of Marine and Tropical Biology, James Cook University, Townsville, Queensland, Australia
| | - Nicholas A. Paul
- MACRO — the Centre for Macroalgal Resources and Biotechnology, and School of Marine and Tropical Biology, James Cook University, Townsville, Queensland, Australia
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204
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Lohman EJ, Gardner RD, Halverson LD, Peyton BM, Gerlach R. Carbon partitioning in lipids synthesized by Chlamydomonas reinhardtii when cultured under three unique inorganic carbon regimes. ALGAL RES 2014. [DOI: 10.1016/j.algal.2014.08.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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205
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Davis RW, Jones HD, Collins AM, Ricken JB, Sinclair MB, Timlin JA, Singh S. Label-free measurement of algal triacylglyceride production using fluorescence hyperspectral imaging. ALGAL RES 2014. [DOI: 10.1016/j.algal.2013.11.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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206
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207
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Yap BH, Crawford SA, Dumsday GJ, Scales PJ, Martin GJ. A mechanistic study of algal cell disruption and its effect on lipid recovery by solvent extraction. ALGAL RES 2014. [DOI: 10.1016/j.algal.2014.07.001] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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208
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Janssen PJD, Lambreva MD, Plumeré N, Bartolucci C, Antonacci A, Buonasera K, Frese RN, Scognamiglio V, Rea G. Photosynthesis at the forefront of a sustainable life. Front Chem 2014; 2:36. [PMID: 24971306 PMCID: PMC4054791 DOI: 10.3389/fchem.2014.00036] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 05/25/2014] [Indexed: 11/13/2022] Open
Abstract
The development of a sustainable bio-based economy has drawn much attention in recent years, and research to find smart solutions to the many inherent challenges has intensified. In nature, perhaps the best example of an authentic sustainable system is oxygenic photosynthesis. The biochemistry of this intricate process is empowered by solar radiation influx and performed by hierarchically organized complexes composed by photoreceptors, inorganic catalysts, and enzymes which define specific niches for optimizing light-to-energy conversion. The success of this process relies on its capability to exploit the almost inexhaustible reservoirs of sunlight, water, and carbon dioxide to transform photonic energy into chemical energy such as stored in adenosine triphosphate. Oxygenic photosynthesis is responsible for most of the oxygen, fossil fuels, and biomass on our planet. So, even after a few billion years of evolution, this process unceasingly supports life on earth, and probably soon also in outer-space, and inspires the development of enabling technologies for a sustainable global economy and ecosystem. The following review covers some of the major milestones reached in photosynthesis research, each reflecting lasting routes of innovation in agriculture, environmental protection, and clean energy production.
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Affiliation(s)
- Paul J. D. Janssen
- Molecular and Cellular Biology - Unit of Microbiology, Institute for Environment, Health and Safety, Belgian Nuclear Research Centre SCK•CENMol, Belgium
| | - Maya D. Lambreva
- Institute of Crystallography, National Research Council of ItalyRome, Italy
| | - Nicolas Plumeré
- Center for Electrochemical Sciences-CES, Ruhr-Universität BochumBochum, Germany
| | - Cecilia Bartolucci
- Institute of Crystallography, National Research Council of ItalyRome, Italy
| | - Amina Antonacci
- Institute of Crystallography, National Research Council of ItalyRome, Italy
| | - Katia Buonasera
- Institute of Crystallography, National Research Council of ItalyRome, Italy
| | - Raoul N. Frese
- Division of Physics and Astronomy, Department of Biophysics, VU University AmsterdamAmsterdam, Netherlands
| | | | - Giuseppina Rea
- Institute of Crystallography, National Research Council of ItalyRome, Italy
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209
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Novoveská L, Henley WJ. Lab-Scale Testing of a Two-Stage Continuous Culture System for Microalgae. Ind Biotechnol (New Rochelle N Y) 2014. [DOI: 10.1089/ind.2013.0034] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Lucie Novoveská
- Department of Botany, Oklahoma State University, Stillwater, OK
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210
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Kenny P, Flynn KJ. In silico optimization for production of biomass and biofuel feedstocks from microalgae. JOURNAL OF APPLIED PHYCOLOGY 2014; 27:33-48. [PMID: 25620851 PMCID: PMC4297880 DOI: 10.1007/s10811-014-0342-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 05/08/2014] [Accepted: 05/08/2014] [Indexed: 05/23/2023]
Abstract
Optimization of the production rate of biomass rich in N (e.g. for protein) or C (e.g. for biofuels) is key to making algae-based technology commercially viable. Creating the appropriate conditions to achieve this is a challenge; operational permutations are extensive, while geographical variations localise effective methods of cultivation when utilising natural illumination. As an aid to identifying suitable operational envelopes, a mechanistic acclimative model of microalgae growth is used for the first time to simulate production in virtual systems over a broad latitudinal range. Optimization of production is achieved through selection of strain characteristics, system optical depth, nutrient supply, and dilution regimes for different geographic and seasonal illumination profiles. Results reveal contrasting requirements for optimising biomass vs biofuels production. Trade-offs between maximising areal and volumetric production while conserving resources, plus hydrodynamic limits on reactor design, lead to quantifiable constraints for optimal operational permutations. Simulations show how selection of strains with a high maximum growth rate, Um , remains the prime factor enabling high productivity. Use of an f/2 growth medium with a culture dilution rate set at ~25 % of Um delivers sufficient nutrition for optimal biomass production. Further, sensitivity to the balance between areal and volumetric productivity leads to a well-defined critical depth at ~0.1 m at which areal biofuel production peaks with use of a low concentration f/4 growth medium combined with a dilution rate ~15 % of Um . Such analyses, and developments thereof, will aid in developing a decision support tool to enable more productive methods of cultivation.
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Affiliation(s)
- Philip Kenny
- Centre for Sustainable Aquatic Research, Department of Biosciences, College of Science, Swansea University, Singleton Park, Swansea, SA2 8PP UK
| | - Kevin J. Flynn
- Centre for Sustainable Aquatic Research, Department of Biosciences, College of Science, Swansea University, Singleton Park, Swansea, SA2 8PP UK
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211
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McBride RC, Lopez S, Meenach C, Burnett M, Lee PA, Nohilly F, Behnke C. Contamination Management in Low Cost Open Algae Ponds for Biofuels Production. Ind Biotechnol (New Rochelle N Y) 2014. [DOI: 10.1089/ind.2013.0036] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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212
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Fields MW, Hise A, Lohman EJ, Bell T, Gardner RD, Corredor L, Moll K, Peyton BM, Characklis GW, Gerlach R. Sources and resources: importance of nutrients, resource allocation, and ecology in microalgal cultivation for lipid accumulation. Appl Microbiol Biotechnol 2014; 98:4805-16. [PMID: 24695829 PMCID: PMC4024127 DOI: 10.1007/s00253-014-5694-7] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 03/13/2014] [Accepted: 03/14/2014] [Indexed: 11/17/2022]
Abstract
Regardless of current market conditions and availability of conventional petroleum sources, alternatives are needed to circumvent future economic and environmental impacts from continued exploration and harvesting of conventional hydrocarbons. Diatoms and green algae (microalgae) are eukaryotic photoautotrophs that can utilize inorganic carbon (e.g., CO2) as a carbon source and sunlight as an energy source, and many microalgae can store carbon and energy in the form of neutral lipids. In addition to accumulating useful precursors for biofuels and chemical feed stocks, the use of autotrophic microorganisms can further contribute to reduced CO2 emissions through utilization of atmospheric CO2. Because of the inherent connection between carbon, nitrogen, and phosphorus in biological systems, macronutrient deprivation has been proven to significantly enhance lipid accumulation in different diatom and algae species. However, much work is needed to understand the link between carbon, nitrogen, and phosphorus in controlling resource allocation at different levels of biological resolution (cellular versus ecological). An improved understanding of the relationship between the effects of N, P, and micronutrient availability on carbon resource allocation (cell growth versus lipid storage) in microalgae is needed in conjunction with life cycle analysis. This mini-review will briefly discuss the current literature on the use of nutrient deprivation and other conditions to control and optimize microalgal growth in the context of cell and lipid accumulation for scale-up processes.
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Affiliation(s)
- Matthew W Fields
- Department of Microbiology and Immunology, Montana State University, 109 Lewis Hall, Bozeman, MT, 59717, USA,
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213
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Nguyen TDP, Frappart M, Jaouen P, Pruvost J, Bourseau P. Harvesting Chlorella vulgaris by natural increase in pH: effect of medium composition. ENVIRONMENTAL TECHNOLOGY 2014; 35:1378-1388. [PMID: 24701936 DOI: 10.1080/09593330.2013.868531] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The freshwater microalga Chlorella vulgaris was harvested by autoflocculation resulting from the precipitation of magnesium or calcium compounds induced by a slow increase in pH in the absence of CO2 input. Autoflocculation was tested in two culture media with, respectively, ammonium (NH4+) and nitrate (NO3-) ions as nitrogen source. The culture pH increased because of photosynthesis and CO2 stripping. pH rose to 11 after 8 h in the NO3- medium, but did not exceed 9 in the NH4+ medium. No flocculation took place in any of the media. Autoflocculation tests were repeated in the NO(3-)-based culture medium by progressively increasing the concentrations of Ca2+ and Mg2+ until inorganic compounds precipitated and flocculated microalgae. The minimal concentrations for flocculation were found to be 120 mg Ca2 L(-1) and 1000 mg Mg2+ L(-1). These values were, respectively, 3.5 times and 20 times higher than those allowing flocculation by NaOH addition. Energy-dispersive X-ray spectroscopy, zeta potential measurement, and ionic chromatography suggest that the mechanisms involved are different. The rate of cell removal was close to 90% in both cases, but cells were more concentrated in the aggregates obtained by magnesium compound precipitation, with an estimated concentration close to 33 g (dry matter) L(-1), against 19 g L(-1) for calcium phosphates.
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214
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Bioconversion of natural gas to liquid fuel: opportunities and challenges. Biotechnol Adv 2014; 32:596-614. [PMID: 24726715 DOI: 10.1016/j.biotechadv.2014.03.011] [Citation(s) in RCA: 152] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 03/29/2014] [Accepted: 03/30/2014] [Indexed: 11/22/2022]
Abstract
Natural gas is a mixture of low molecular weight hydrocarbon gases that can be generated from either fossil or anthropogenic resources. Although natural gas is used as a transportation fuel, constraints in storage, relatively low energy content (MJ/L), and delivery have limited widespread adoption. Advanced utilization of natural gas has been explored for biofuel production by microorganisms. In recent years, the aerobic bioconversion of natural gas (or primarily the methane content of natural gas) into liquid fuels (Bio-GTL) by biocatalysts (methanotrophs) has gained increasing attention as a promising alternative for drop-in biofuel production. Methanotrophic bacteria are capable of converting methane into microbial lipids, which can in turn be converted into renewable diesel via a hydrotreating process. In this paper, biodiversity, catalytic properties and key enzymes and pathways of these microbes are summarized. Bioprocess technologies are discussed based upon existing literature, including cultivation conditions, fermentation modes, bioreactor design, and lipid extraction and upgrading. This review also outlines the potential of Bio-GTL using methane as an alternative carbon source as well as the major challenges and future research needs of microbial lipid accumulation derived from methane, key performance index, and techno-economic analysis. An analysis of raw material costs suggests that methane-derived diesel fuel has the potential to be competitive with petroleum-derived diesel.
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215
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Rogers JN, Rosenberg JN, Guzman BJ, Oh VH, Mimbela LE, Ghassemi A, Betenbaugh MJ, Oyler GA, Donohue MD. A critical analysis of paddlewheel-driven raceway ponds for algal biofuel production at commercial scales. ALGAL RES 2014. [DOI: 10.1016/j.algal.2013.11.007] [Citation(s) in RCA: 160] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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216
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Takeshita T, Ota S, Yamazaki T, Hirata A, Zachleder V, Kawano S. Starch and lipid accumulation in eight strains of six Chlorella species under comparatively high light intensity and aeration culture conditions. BIORESOURCE TECHNOLOGY 2014; 158:127-34. [PMID: 24583913 DOI: 10.1016/j.biortech.2014.01.135] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 01/29/2014] [Accepted: 01/31/2014] [Indexed: 05/12/2023]
Abstract
The microalgae family Chlorella species are known to accumulate starch and lipids. Although nitrogen or phosphorous deficiencies promote starch and lipids formation in many microalgae, these deficiencies also limit their growth and productivity. Therefore, the Chlorellaceae strains were attempted to increase starch and lipids productivity under high-light-intensity conditions (600-μmol photons m(-2)s(-1)). The 12:12-h light-dark (LD) cycle conditions elicited more stable growth than the continuous light (LL) conditions, whereas the starch and lipids yields increased in LL conditions. The amount of starch and lipids per cell increased in Chlorella viscosa and Chlorella vulgaris in sulfur-deficient medium, and long-chain fatty acids with 20 or more carbon atoms accumulated in cells grown in sulfur-deficient medium. Accumulation of starch and lipids was investigated in eight strains. The accumulation was strain-dependent, and varied according to the medium and light conditions. Five of the eight Chlorella strains exhibited similar accumulation patterns.
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Affiliation(s)
- Tsuyoshi Takeshita
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Shuhei Ota
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan; Japan Science and Technology Agency, CREST, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Tomokazu Yamazaki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan; Japan Science and Technology Agency, CREST, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Aiko Hirata
- Bioimaging Center, Graduate School of Frontier Science, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Vilém Zachleder
- Laboratory of the Cell Cycles of Algae, Institute of Microbiology, Academy of Sciences of the Czech Republic, Opatovický mlýn, Třeboň 379 81, Czech Republic
| | - Shigeyuki Kawano
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan; Japan Science and Technology Agency, CREST, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan.
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217
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Bernardi A, Perin G, Sforza E, Galvanin F, Morosinotto T, Bezzo F. An Identifiable State Model To Describe Light Intensity Influence on Microalgae Growth. Ind Eng Chem Res 2014; 53:6738-6749. [PMID: 25678739 PMCID: PMC4311933 DOI: 10.1021/ie500523z] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 03/21/2014] [Accepted: 03/23/2014] [Indexed: 11/28/2022]
Abstract
Despite the high potential as feedstock
for the production of fuels
and chemicals, the industrial cultivation of microalgae still exhibits
many issues. Yield in microalgae cultivation systems is limited by
the solar energy that can be harvested. The availability of reliable
models representing key phenomena affecting algae growth may help
designing and optimizing effective production systems at an industrial
level. In this work the complex influence of different light regimes
on seawater alga Nannochloropsis salina growth is
represented by first principles models. Experimental data such as in vivo fluorescence measurements are employed to develop
the model. The proposed model allows description of all growth curves
and fluorescence data in a reliable way. The model structure is assessed
and modified in order to guarantee the model identifiability and the
estimation of its parametric set in a robust and reliable way.
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Affiliation(s)
- A Bernardi
- CAPE-Lab-Computer Aided Process Engineering Laboratory, Department of Industrial Engineering, University of Padova , via Marzolo 9, 35131 Padova, Padua, Italy ; PAR-Lab-Padova Algae Research Laboratory, Department of Industrial Engineering, University of Padova via Marzolo 9, 35131 Padova, Padua, Italy
| | - G Perin
- PAR-Lab-Padova Algae Research Laboratory, Department of Biology, University of Padova , via U. Bassi 58 B, 35131 Padova, Padova, Italy
| | - E Sforza
- PAR-Lab-Padova Algae Research Laboratory, Department of Industrial Engineering, University of Padova via Marzolo 9, 35131 Padova, Padua, Italy
| | - F Galvanin
- CAPE-Lab-Computer Aided Process Engineering Laboratory, Department of Industrial Engineering, University of Padova , via Marzolo 9, 35131 Padova, Padua, Italy
| | - T Morosinotto
- PAR-Lab-Padova Algae Research Laboratory, Department of Biology, University of Padova , via U. Bassi 58 B, 35131 Padova, Padova, Italy
| | - F Bezzo
- CAPE-Lab-Computer Aided Process Engineering Laboratory, Department of Industrial Engineering, University of Padova , via Marzolo 9, 35131 Padova, Padua, Italy ; PAR-Lab-Padova Algae Research Laboratory, Department of Industrial Engineering, University of Padova via Marzolo 9, 35131 Padova, Padua, Italy
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218
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Han SF, Jin WB, Tu RJ, Wu WM. Biofuel production from microalgae as feedstock: current status and potential. Crit Rev Biotechnol 2014; 35:255-68. [DOI: 10.3109/07388551.2013.835301] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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219
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Levitan O, Dinamarca J, Hochman G, Falkowski PG. Diatoms: a fossil fuel of the future. Trends Biotechnol 2014; 32:117-24. [PMID: 24529448 DOI: 10.1016/j.tibtech.2014.01.004] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 12/18/2013] [Accepted: 01/08/2014] [Indexed: 11/16/2022]
Abstract
Long-term global climate change, caused by burning petroleum and other fossil fuels, has motivated an urgent need to develop renewable, carbon-neutral, economically viable alternatives to displace petroleum using existing infrastructure. Algal feedstocks are promising candidate replacements as a 'drop-in' fuel. Here, we focus on a specific algal taxon, diatoms, to become the fossil fuel of the future. We summarize past attempts to obtain suitable diatom strains, propose future directions for their genetic manipulation, and offer biotechnological pathways to improve yield. We calculate that the yields obtained by using diatoms as a production platform are theoretically sufficient to satisfy the total oil consumption of the US, using between 3 and 5% of its land area.
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Affiliation(s)
- Orly Levitan
- Environmental Biophysics and Molecular Ecology Program, Institute of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ 08901, USA.
| | - Jorge Dinamarca
- Environmental Biophysics and Molecular Ecology Program, Institute of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ 08901, USA.
| | - Gal Hochman
- Department of Agriculture, Food & Resource Economics, Rutgers University, New Brunswick, NJ 08901, USA
| | - Paul G Falkowski
- Environmental Biophysics and Molecular Ecology Program, Institute of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ 08901, USA; Department of Earth and Planetary Sciences, Rutgers University, Piscataway, NJ 0885, USA
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220
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Chen M, Li J, Zhang L, Chang S, Liu C, Wang J, Li S. Auto-flotation of heterocyst enables the efficient production of renewable energy in cyanobacteria. Sci Rep 2014; 4:3998. [PMID: 24499777 PMCID: PMC3915303 DOI: 10.1038/srep03998] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 01/16/2014] [Indexed: 11/18/2022] Open
Abstract
Utilizing cyanobacteria as a bioenergy resource is difficult due to the cost and energy consuming harvests of microalgal biomass. In this study, an auto-floating system was developed by increasing the photobiological H2 production in the heterocysts of filamentous cyanobacteria. An amount of 1.0 μM of diuron, which inhibited O2 production in cyanobacteria, resulted in a high rate of H2 production in heterocysts. The auto-floating process recovered 91.71% ± 1.22 of the accumulated microalgal biomass from the liquid media. Quantification analysis revealed that 0.72–1.10 μmol H2 per mg dry weight microalgal biomass was necessary to create this auto-floating system. Further bio-conversion by using anaerobic digestion converted the harvested microalgal biomass into biogas. Through this novel coupled system of photobiological H2 production and anaerobic digestion, a high level of light energy conversion efficiency from solar energy to bioenergy was attained with the values of 3.79% ± 0.76.
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Affiliation(s)
- Ming Chen
- 1] Institute of New Energy Technology, Tsinghua University, Tsinghua Garden, Beijing100084, China [2] Beijing Engineering Research Center for Biofuels, Tsinghua University, Tsinghua Garden, Beijing 100084, China
| | - Jihong Li
- 1] Institute of New Energy Technology, Tsinghua University, Tsinghua Garden, Beijing100084, China [2] Beijing Engineering Research Center for Biofuels, Tsinghua University, Tsinghua Garden, Beijing 100084, China
| | - Lei Zhang
- 1] Institute of New Energy Technology, Tsinghua University, Tsinghua Garden, Beijing100084, China [2] Beijing Engineering Research Center for Biofuels, Tsinghua University, Tsinghua Garden, Beijing 100084, China
| | - Sandra Chang
- 1] Institute of New Energy Technology, Tsinghua University, Tsinghua Garden, Beijing100084, China [2] Beijing Engineering Research Center for Biofuels, Tsinghua University, Tsinghua Garden, Beijing 100084, China
| | - Chen Liu
- Institute of New Energy Technology, Tsinghua University, Tsinghua Garden, Beijing100084, China
| | - Jianlong Wang
- Institute of New Energy Technology, Tsinghua University, Tsinghua Garden, Beijing100084, China
| | - Shizhong Li
- 1] Institute of New Energy Technology, Tsinghua University, Tsinghua Garden, Beijing100084, China [2] Beijing Engineering Research Center for Biofuels, Tsinghua University, Tsinghua Garden, Beijing 100084, China
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221
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Weschler MK, Barr WJ, Harper WF, Landis AE. Process energy comparison for the production and harvesting of algal biomass as a biofuel feedstock. BIORESOURCE TECHNOLOGY 2014; 153:108-15. [PMID: 24355501 DOI: 10.1016/j.biortech.2013.11.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 10/30/2013] [Accepted: 11/07/2013] [Indexed: 05/10/2023]
Abstract
Harvesting and drying are often described as the most energy intensive stages of microalgal biofuel production. This study analyzes two cultivation and eleven harvest technologies for the production of microalgae biomass with and without the use of drying. These technologies were combined to form 122 different production scenarios. The results of this study present a calculation methodology and optimization of total energy demand for the production of algal biomass for biofuel production. The energetic interaction between unit processes and total process energy demand are compared for each scenario. Energy requirements are shown to be highly dependent on final mass concentration, with thermal drying being the largest energy consumer. Scenarios that omit thermal drying in favor of lipid extraction from wet biomass show the most promise for energy efficient biofuel production. Scenarios which used open ponds for cultivation, followed by settling and membrane filtration were the most energy efficient.
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Affiliation(s)
- Matthew K Weschler
- Department of Civil and Environmental Engineering, University of Pittsburgh, 3700 O'Hara Street, Pittsburgh, PA 15261, United States
| | - William J Barr
- School of Sustainable Engineering and the Built Environment, Global Institute of Sustainability, Arizona State University, ISTB4 781 E Terrace Road, Tempe, AZ 85287, United States
| | - Willie F Harper
- Department of Systems and Engineering Management, Air Force Institute of Technology, 2950 Hobson Way, WPAFB, OH 45433, United States
| | - Amy E Landis
- School of Sustainable Engineering and the Built Environment, Global Institute of Sustainability, Arizona State University, ISTB4 781 E Terrace Road, Tempe, AZ 85287, United States.
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222
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Li Y, Ghasemi Naghdi F, Garg S, Adarme-Vega TC, Thurecht KJ, Ghafor WA, Tannock S, Schenk PM. A comparative study: the impact of different lipid extraction methods on current microalgal lipid research. Microb Cell Fact 2014; 13:14. [PMID: 24456581 PMCID: PMC3926349 DOI: 10.1186/1475-2859-13-14] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 01/19/2014] [Indexed: 12/03/2022] Open
Abstract
Microalgae cells have the potential to rapidly accumulate lipids, such as triacylglycerides that contain fatty acids important for high value fatty acids (e.g., EPA and DHA) and/or biodiesel production. However, lipid extraction methods for microalgae cells are not well established, and there is currently no standard extraction method for the determination of the fatty acid content of microalgae. This has caused a few problems in microlagal biofuel research due to the bias derived from different extraction methods. Therefore, this study used several extraction methods for fatty acid analysis on marine microalga Tetraselmis sp. M8, aiming to assess the potential impact of different extractions on current microalgal lipid research. These methods included classical Bligh & Dyer lipid extraction, two other chemical extractions using different solvents and sonication, direct saponification and supercritical CO2 extraction. Soxhlet-based extraction was used to weigh out the importance of solvent polarity in the algal oil extraction. Coupled with GC/MS, a Thermogravimetric Analyser was used to improve the quantification of microalgal lipid extractions. Among these extractions, significant differences were observed in both, extract yield and fatty acid composition. The supercritical extraction technique stood out most for effective extraction of microalgal lipids, especially for long chain unsaturated fatty acids. The results highlight the necessity for comparative analyses of microalgae fatty acids and careful choice and validation of analytical methodology in microalgal lipid research.
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Affiliation(s)
- Yan Li
- School of Agriculture and Food Sciences, The University of Queensland, Brisbane QLD 4072, Australia.
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223
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The effect of Diel temperature and light cycles on the growth of nannochloropsis oculata in a photobioreactor matrix. PLoS One 2014; 9:e86047. [PMID: 24465862 PMCID: PMC3896454 DOI: 10.1371/journal.pone.0086047] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Accepted: 12/04/2013] [Indexed: 11/19/2022] Open
Abstract
A matrix of photobioreactors integrated with metabolic sensors was used to examine the combined impact of light and temperature variations on the growth and physiology of the biofuel candidate microalgal species Nannochloropsis oculata. The experiments were performed with algal cultures maintained at a constant 20 °C versus a 15 °C to 25 °C diel temperature cycle, where light intensity also followed a diel cycle with a maximum irradiance of 1920 µmol photons m(-2) s(-1). No differences in algal growth (Chlorophyll a) were found between the two environmental regimes; however, the metabolic processes responded differently throughout the day to the change in environmental conditions. The variable temperature treatment resulted in greater damage to photosystem II due to the combined effect of strong light and high temperature. Cellular functions responded differently to conditions before midday as opposed to the afternoon, leading to strong hysteresis in dissolved oxygen concentration, quantum yield of photosystem II and net photosynthesis. Overnight metabolism performed differently, probably as a result of the temperature impact on respiration. Our photobioreactor matrix has produced novel insights into the physiological response of Nannochloropsis oculata to simulated environmental conditions. This information can be used to predict the effectiveness of deploying Nannochloropsis oculata in similar field conditions for commercial biofuel production.
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224
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Flynn KJ, Mitra A, Greenwell HC, Sui J. Monster potential meets potential monster: pros and cons of deploying genetically modified microalgae for biofuels production. Interface Focus 2014; 3:20120037. [PMID: 24427510 DOI: 10.1098/rsfs.2012.0037] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Biofuels production from microalgae attracts much attention but remains an unproven technology. We explore routes to enhance production through modifications to a range of generic microalgal physiological characteristics. Our analysis shows that biofuels production may be enhanced ca fivefold through genetic modification (GM) of factors affecting growth rate, respiration, photoacclimation, photosynthesis efficiency and the minimum cell quotas for nitrogen and phosphorous (N : C and P : C). However, simulations indicate that the ideal GM microalgae for commercial deployment could, on escape to the environment, become a harmful algal bloom species par excellence, with attendant risks to ecosystems and livelihoods. In large measure, this is because an organism able to produce carbohydrate and/or lipid at high rates, providing stock metabolites for biofuels production, will also be able to attain a stoichiometric composition that will be far from optimal as food for the support of zooplankton growth. This composition could suppress or even halt the grazing activity that would otherwise control the microalgal growth in nature. In consequence, we recommend that the genetic manipulation of microalgae, with inherent consequences on a scale comparable to geoengineering, should be considered under strict international regulation.
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Affiliation(s)
- K J Flynn
- Centre of Sustainable Aquatic Research , Swansea University , Swansea SA2 8PP , UK
| | - A Mitra
- Centre of Sustainable Aquatic Research , Swansea University , Swansea SA2 8PP , UK
| | - H C Greenwell
- Department of Earth Sciences , Durham University , Durham DH1 3LE , UK
| | - J Sui
- Centre of Sustainable Aquatic Research , Swansea University , Swansea SA2 8PP , UK
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225
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Chellamboli C, Perumalsamy M. Application of response surface methodology for optimization of growth and lipids in Scenedesmus abundans using batch culture system. RSC Adv 2014. [DOI: 10.1039/c4ra01179a] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Owing to an increased demand for fuel and the depletion of fossil fuels, an alternative source such as algae is currently being exploited for biofuel production.
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Affiliation(s)
- Chelladurai Chellamboli
- Department of Chemical Engineering
- National Institute of Technology
- Tiruchirappalli – 620015, India
| | - Muthiah Perumalsamy
- Department of Chemical Engineering
- National Institute of Technology
- Tiruchirappalli – 620015, India
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226
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The chloroplast signal recognition particle (CpSRP) pathway as a tool to minimize chlorophyll antenna size and maximize photosynthetic productivity. Biotechnol Adv 2014; 32:66-72. [DOI: 10.1016/j.biotechadv.2013.08.018] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Revised: 08/28/2013] [Accepted: 08/29/2013] [Indexed: 11/21/2022]
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227
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Pérez-López P, González-García S, Allewaert C, Verween A, Murray P, Feijoo G, Moreira MT. Environmental evaluation of eicosapentaenoic acid production by Phaeodactylum tricornutum. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 466-467:991-1002. [PMID: 23994733 DOI: 10.1016/j.scitotenv.2013.07.105] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 07/22/2013] [Accepted: 07/28/2013] [Indexed: 06/02/2023]
Abstract
Polyunsaturated fatty acids (PUFAs) play an important role in human health. Due to the increased market demand, the production of PUFAs from potential alternative sources such as microalgae is receiving increased interest. The aim of this study was to perform a life cycle assessment (LCA) of the biotechnological production of eicosapentaenoic acid (EPA) from the marine diatom Phaeodactylum tricornutum, followed by the identification of avenues to improve its environmental profile. The LCA tackles two production schemes of P. tricornutum PUFAs with an EPA content of 36%: lab and pilot scales. The results at lab scale show that both the electricity requirements and the production of the extraction agent (chloroform) have significant influence on the life cycle environmental performance of microalgal EPA production. An alternative method based on hexane was proposed to replace chloroform and environmental benefits were identified. Regarding the production of EPA at pilot scale, three main environmental factors were identified: the production of the nitrogen source required for microalgae growing, the transport activities and electricity requirements. Improvement alternatives were proposed and discussed concerning: a) the use of nitrogen based fertilizers, b) the valorization of the residual algal paste as soil conditioner and, c) the anaerobic digestion of the residual algal paste for bioenergy production. Encouraging environmental benefits could be achieved if sodium nitrate was substituted by urea, calcium nitrate or ammonium nitrate, regardless the category under assessment. In contrast, minor improvement was found when valorizing the residual algal paste as mineral fertilizer, due to its overall low content in N and P. Concerning the biogas production from the anaerobic digestion, the improvement on the environmental profile was also limited due to the discrepancy between the potential energy production from the algal paste and the high electricity requirements in the culturing and extraction stages.
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Affiliation(s)
- Paula Pérez-López
- Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain
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228
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Lizzul AM, Hellier P, Purton S, Baganz F, Ladommatos N, Campos L. Combined remediation and lipid production using Chlorella sorokiniana grown on wastewater and exhaust gases. BIORESOURCE TECHNOLOGY 2014; 151:12-8. [PMID: 24189380 DOI: 10.1016/j.biortech.2013.10.040] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 10/12/2013] [Accepted: 10/14/2013] [Indexed: 05/07/2023]
Abstract
Substitution of conventional feedstock with waste based alternatives is one route towards both remediation and reducing costs associated with production of algal biomass. This work explores whether exhaust gases and wastewater can replace conventional feedstock in the production of biomass from Chlorella sorokiniana. Exhaust gases were used to augment production in final effluent, anaerobic digester centrate or in standard medium. Cultures were grown in 1L bottles under illumination of 80 μmol m(-2) s(-1). The results showed an average μmax ranging between 0.04 and 0.07 h(-1), whilst the final biomass yield in different media ranged between 220 and 330 mg L(-1). Lipid yield was increased over time to 31 mg L(-1). CO2 addition resulted in complete nitrogen removal between 48 and 96 h in both final effluent and centrate. The results also indicated that levels of carbon monoxide, carbon dioxide and nitrogen oxides in the exhaust gases can be reduced by between 20% and 95%.
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Affiliation(s)
- A M Lizzul
- Centre for Urban Sustainability and Resilience, University College London, Gower Street, London WC1E 6BT, United Kingdom.
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229
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Zhang J, Hao Q, Bai L, Xu J, Yin W, Song L, Xu L, Guo X, Fan C, Chen Y, Ruan J, Hao S, Li Y, Wang RRC, Hu Z. Overexpression of the soybean transcription factor GmDof4 significantly enhances the lipid content of Chlorella ellipsoidea. BIOTECHNOLOGY FOR BIOFUELS 2014; 7:128. [PMID: 25246944 PMCID: PMC4159510 DOI: 10.1186/s13068-014-0128-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 08/20/2014] [Indexed: 05/02/2023]
Abstract
BACKGROUND The lipid content of microalgae is regarded as an important indicator for biodiesel. Many attempts have been made to increase the lipid content of microalgae through biochemical and genetic engineering. Significant lipid accumulation in microalgae has been achieved using biochemical engineering, such as nitrogen starvation, but the cell growth was severely limited. However, enrichment of lipid content in microalgae by genetic engineering is anticipated. In this study, GmDof4 from soybean (Glycine max), a transcription factor affecting the lipid content in Arabidopsis, was transferred into Chlorella ellipsoidea. We then investigated the molecular mechanism underlying the enhancement of the lipid content of transformed C. ellipsoidea. RESULTS We constructed a plant expression vector, pGmDof4, and transformed GmDof4 into C. ellipsoidea by electroporation. The resulting expression of GmDof4 significantly enhanced the lipid content by 46.4 to 52.9%, but did not affect the growth rate of the host cells under mixotrophic culture conditions. Transcriptome profiles indicated that 1,076 transcripts were differentially regulated: of these, 754 genes were significantly upregulated and 322 genes were significantly downregulated in the transgenic strains under mixotrophic culture conditions. There are 22 significantly regulated genes (|log2 ratio| >1) involved in lipid and fatty acid metabolism. Quantitative real-time PCR and an enzyme activity assay revealed that GmDof4 significantly up-regulated the gene expression and enzyme activity of acetyl-coenzyme A carboxylase, a key enzyme for fatty acid synthesis, in transgenic C. ellipsoidea cells. CONCLUSIONS The hetero-expression of a transcription factor GmDof4 gene from soybean can significantly increase the lipid content but not affect the growth rate of C. ellipsoidea under mixotrophic culture conditions. The increase in lipid content could be attributed to the large number of genes with regulated expression. In particular, the acetyl-coenzyme A carboxylase gene expression and enzyme activity were significantly upregulated in the transgenic cells. Our research provides a new way to increase the lipid content of microalgae by introducing a specific transcription factor to microalgae strains that can be used for the biofuel and food industries.
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Affiliation(s)
- Jianhui Zhang
- />Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Datun Road, Chaoyang District, Beijing, 100101 China
| | - Qiang Hao
- />Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Datun Road, Chaoyang District, Beijing, 100101 China
- />College of Life Sciences, University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049 China
| | - Lili Bai
- />Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Datun Road, Chaoyang District, Beijing, 100101 China
| | - Jin Xu
- />Beijing Institute of Genomics, Chinese Academy of Sciences, Beichen West Road #1, Beijing, 100029 China
| | - Weibo Yin
- />Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Datun Road, Chaoyang District, Beijing, 100101 China
| | - Liying Song
- />Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Datun Road, Chaoyang District, Beijing, 100101 China
| | - Ling Xu
- />Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Datun Road, Chaoyang District, Beijing, 100101 China
| | - Xuejie Guo
- />Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Datun Road, Chaoyang District, Beijing, 100101 China
| | - Chengming Fan
- />Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Datun Road, Chaoyang District, Beijing, 100101 China
| | - Yuhong Chen
- />Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Datun Road, Chaoyang District, Beijing, 100101 China
| | - Jue Ruan
- />Beijing Institute of Genomics, Chinese Academy of Sciences, Beichen West Road #1, Beijing, 100029 China
| | - Shanting Hao
- />Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Datun Road, Chaoyang District, Beijing, 100101 China
| | - Yuanguang Li
- />State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Meilong Road #130, Shanghai, 200237 China
| | - Richard R-C Wang
- />USDA-ARS, FRRL, Utah State University, 695 N. 1100 E., Logan, UT 84322-6300 USA
| | - Zanmin Hu
- />Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Datun Road, Chaoyang District, Beijing, 100101 China
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230
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Zhang Y, Zhao Y, Chu H, Zhou X, Dong B. Dewatering of Chlorella pyrenoidosa using diatomite dynamic membrane: Filtration performance, membrane fouling and cake behavior. Colloids Surf B Biointerfaces 2014; 113:458-66. [DOI: 10.1016/j.colsurfb.2013.09.046] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 08/21/2013] [Accepted: 09/20/2013] [Indexed: 10/26/2022]
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231
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Shen Y. Carbon dioxide bio-fixation and wastewater treatment via algae photochemical synthesis for biofuels production. RSC Adv 2014. [DOI: 10.1039/c4ra06441k] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Utilizing the energy, nutrients and CO2held within residual waste materials to provide all necessary inputs except for sunlight, the cultivation of algae becomes a closed-loop engineered ecosystem. Developing this green biotechnology is a tangible step towards a waste-free sustainable society.
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Affiliation(s)
- Yafei Shen
- Department of Environmental Science and Technology
- Interdisciplinary Graduate School of Science and Engineering
- Tokyo Institute of Technology
- Yokohama, Japan
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232
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Influence of magnesium concentration, biomass concentration and pH on flocculation of Chlorella vulgaris. ALGAL RES 2014. [DOI: 10.1016/j.algal.2013.11.016] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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233
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Balan R, Suraishkumar GK. Simultaneous increases in specific growth rate and specific lipid content ofChlorella vulgaristhrough UV-induced reactive species. Biotechnol Prog 2013; 30:291-9. [DOI: 10.1002/btpr.1854] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 11/05/2013] [Indexed: 11/12/2022]
Affiliation(s)
- Ranjini Balan
- Dept. of Biotechnology; Indian Inst. of Technology Madras; Chennai 600036 Tamil Nadu India
| | - G. K. Suraishkumar
- Dept. of Biotechnology; Indian Inst. of Technology Madras; Chennai 600036 Tamil Nadu India
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234
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Cultivation of Scenedesmus obliquus in Photobioreactors: Effects of Light Intensities and Light–Dark Cycles on Growth, Productivity, and Biochemical Composition. Appl Biochem Biotechnol 2013; 172:2377-89. [DOI: 10.1007/s12010-013-0679-z] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 12/05/2013] [Indexed: 10/25/2022]
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235
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Choi HJ, Montemagno CD. Recent Progress in Advanced Nanobiological Materials for Energy and Environmental Applications. MATERIALS 2013; 6:5821-5856. [PMID: 28788424 PMCID: PMC5452742 DOI: 10.3390/ma6125821] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 11/26/2013] [Accepted: 11/28/2013] [Indexed: 11/25/2022]
Abstract
In this review, we briefly introduce our efforts to reconstruct cellular life processes by mimicking natural systems and the applications of these systems to energy and environmental problems. Functional units of in vitro cellular life processes are based on the fabrication of artificial organelles using protein-incorporated polymersomes and the creation of bioreactors. This concept of an artificial organelle originates from the first synthesis of poly(siloxane)-poly(alkyloxazoline) block copolymers three decades ago and the first demonstration of protein activity in the polymer membrane a decade ago. The increased value of biomimetic polymers results from many research efforts to find new applications such as functionally active membranes and a biochemical-producing polymersome. At the same time, foam research has advanced to the point that biomolecules can be efficiently produced in the aqueous channels of foam. Ongoing research includes replication of complex biological processes, such as an artificial Calvin cycle for application in biofuel and specialty chemical production, and carbon dioxide sequestration. We believe that the development of optimally designed biomimetic polymers and stable/biocompatible bioreactors would contribute to the realization of the benefits of biomimetic systems. Thus, this paper seeks to review previous research efforts, examine current knowledge/key technical parameters, and identify technical challenges ahead.
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Affiliation(s)
- Hyo-Jick Choi
- National Institute for Nanotechnology and Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 2M9, Canada.
| | - Carlo D Montemagno
- National Institute for Nanotechnology and Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 2M9, Canada.
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236
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Korkhovoy VI, Blume YB. Biodiesel from microalgae: Ways for increasing the effectiveness of lipid accumulation by genetic engineering methods. CYTOL GENET+ 2013. [DOI: 10.3103/s0095452713060030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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237
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Song P, Li L, Liu J. Proteomic analysis in nitrogen-deprived Isochrysis galbana during lipid accumulation. PLoS One 2013; 8:e82188. [PMID: 24340005 PMCID: PMC3855430 DOI: 10.1371/journal.pone.0082188] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Accepted: 10/22/2013] [Indexed: 11/30/2022] Open
Abstract
The differentially co-expressed proteins in N-deprived and N-enriched I. galbana were comparatively analyzed by using two dimensional electrophoresis (2-DE) and matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight-mass spectrometry (MALDI-TOF/TOF-MS) with the aim of better understanding lipid metabolism in this oleaginous microalga. Forty-five of the 900 protein spots showed dramatic changes in N-deprived I. galbana compared with the N-enriched cells. Of these, 36 protein spots were analyzed and 27 proteins were successfully identified. The identified proteins were classified into seven groups by their molecular functions, including the proteins related to energy production and transformation, substance metabolism, signal transduction, molecular chaperone, transcription and translation, immune defense and cytoskeleton. These altered proteins slowed cell growth and photosynthesis of I. galbana directly or indirectly, but at the same time increased lipid accumulation. Eight key enzymes involved in lipid metabolism via different pathways were identified as glyceraldehyde-3-phosphate dehydrogenase (GAPDH), phosphoglycerate kinase (PGK), enolase, aspartate aminotransferase (AST), fumarate hydratase (FH), citrate synthase (CS), O-acetyl-serine lyase (OAS-L) and ATP sulfurylase (ATPS). The results suggested that the glycolytic pathway and citrate transport system might be the main routes for lipid anabolism in N-deprived I. galbana, and that the tricarboxylic acid (TCA) cycle, glyoxylate cycle and sulfur assimilation system might be the major pathways involved in lipid catabolism.
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Affiliation(s)
- Pingping Song
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Graduate University of Chinese Academy of Sciences, Beijing, China
- * E-mail:
| | - Ling Li
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Jianguo Liu
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
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238
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Kobayashi N, Noel EA, Barnes A, Watson A, Rosenberg JN, Erickson G, Oyler GA. Characterization of three Chlorella sorokiniana strains in anaerobic digested effluent from cattle manure. BIORESOURCE TECHNOLOGY 2013; 150:377-386. [PMID: 24185420 DOI: 10.1016/j.biortech.2013.10.032] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 10/07/2013] [Accepted: 10/10/2013] [Indexed: 06/02/2023]
Abstract
Chlorella sorokiniana CS-01, UTEX 1230 and UTEX 2714 were maintained in 10% anaerobic digester effluent (ADE) from cattle manure digestion and compared with algal cultivation in Bold's Basal Medium (BBM). Biomass of CS-01 and UTEX 1230 in ADE produced similar or greater than 280mg/L after 21days in BBM, however, UTEX 2714 growth in ADE was suppressed by more than 50% demonstrating a significant species bias to synthetic compared to organic waste-based media. The highest accumulation of protein and starch was exhibited in UTEX 1230 in ADE yielding 34% and 23% ash free dry weight (AFDW), respectively, though fatty acid methyl ester total lipid measured less than 12% AFDW. Results suggest that biomass from UTEX 1230 in ADE may serve as a candidate alga and growth system combination sustainable for animal feed production considering high yields of protein, starch and low lipid accumulation.
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Affiliation(s)
- Naoko Kobayashi
- Department of Biochemistry, University of Nebraska-Lincoln, 1901 Vine Street, Lincoln, NE 68588, United States
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239
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Discart V, Bilad MR, Marbelia L, Vankelecom IFJ. Impact of changes in broth composition on Chlorella vulgaris cultivation in a membrane photobioreactor (MPBR) with permeate recycle. BIORESOURCE TECHNOLOGY 2013; 152:321-328. [PMID: 24315936 DOI: 10.1016/j.biortech.2013.11.019] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 11/07/2013] [Accepted: 11/11/2013] [Indexed: 06/02/2023]
Abstract
A membrane photobioreactor (MPBR) is a proven and very useful concept in which microalgae can be simultaneously cultivated and pre-harvested. However, the behavior with respect to accumulation of algogenic organic matter, including transparent exopolymeric particles (TEPs), counter ions and unassimilated nutrients due to the recycling of the medium is still unclear, even though the understanding of this behavior is essential for the optimization of microalgae processing. Therefore, the dynamics of these compounds, especially TEPs, during coupled cultivation and harvesting of Chlorella vulgaris in an MPBR with permeate recycle are addressed in this study. Results show that TEPs are secreted during algae cell growth, and that their presence is thus inevitable. In the system with permeate recycle, substances such as counter ions and unassimilated nutrients get accumulated in the system. This was proven to limit the algae growth, together with the occurrence of bioflocculation due to an increasing broth pH.
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Affiliation(s)
- V Discart
- Centre for Surface Chemistry and Catalysis, Faculty of Bioscience Engineering, KU Leuven, Kasteelpark Arenberg 23, Box 2461, 3001 Leuven, Belgium
| | - M R Bilad
- Centre for Surface Chemistry and Catalysis, Faculty of Bioscience Engineering, KU Leuven, Kasteelpark Arenberg 23, Box 2461, 3001 Leuven, Belgium
| | - L Marbelia
- Centre for Surface Chemistry and Catalysis, Faculty of Bioscience Engineering, KU Leuven, Kasteelpark Arenberg 23, Box 2461, 3001 Leuven, Belgium
| | - I F J Vankelecom
- Centre for Surface Chemistry and Catalysis, Faculty of Bioscience Engineering, KU Leuven, Kasteelpark Arenberg 23, Box 2461, 3001 Leuven, Belgium.
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240
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Mayers JJ, Flynn KJ, Shields RJ. Rapid determination of bulk microalgal biochemical composition by Fourier-Transform Infrared spectroscopy. BIORESOURCE TECHNOLOGY 2013; 148:215-20. [PMID: 24050924 DOI: 10.1016/j.biortech.2013.08.133] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 08/20/2013] [Accepted: 08/23/2013] [Indexed: 05/12/2023]
Abstract
Analysis of bulk biochemical composition is a key in fundamental and applied studies of microalgae and is essential to understanding responses to different cultivation scenarios. Traditional biochemical methods for the quantification of lipids, carbohydrates and proteins are often time-consuming, often involve hazardous reagents, require significant amounts of biomass and are highly dependent on practitioner proficiency. This study presents a rapid and non-destructive method, utilising Fourier-Transform Infrared (FTIR) spectroscopy for the simultaneous determination of lipid, protein and carbohydrate content in microalgal biomass. A simple univariate regression was applied to sets of reference microalgal spectra of known composition and recognised IR peak integrals. A robust single-species model was constructed, with coefficients of determination r(2)>0.95, high predictive accuracy and relative errors below 5%. The applicability of this methodology is demonstrated by monitoring the time-resolved changes in biochemical composition of the marine alga Nannochloropsis sp. grown to nitrogen starvation.
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Affiliation(s)
- Joshua J Mayers
- Centre for Sustainable Aquatic Research, Swansea University, Swansea SA2 8PP, UK
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241
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Xiao M, Shin HJ, Dong Q. Advances in cultivation and processing techniques for microalgal biodiesel: A review. KOREAN J CHEM ENG 2013. [DOI: 10.1007/s11814-013-0161-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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242
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Bigelow N, Barker J, Ryken S, Patterson J, Hardin W, Barlow S, Deodato C, Cattolico RA. Chrysochromulina sp.: A proposed lipid standard for the algal biofuel industry and its application to diverse taxa for screening lipid content. ALGAL RES 2013. [DOI: 10.1016/j.algal.2013.07.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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243
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Goettel M, Eing C, Gusbeth C, Straessner R, Frey W. Pulsed electric field assisted extraction of intracellular valuables from microalgae. ALGAL RES 2013. [DOI: 10.1016/j.algal.2013.07.004] [Citation(s) in RCA: 190] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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244
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Takisawa K, Kanemoto K, Miyazaki T, Kitamura Y. Hydrolysis for direct esterification of lipids from wet microalgae. BIORESOURCE TECHNOLOGY 2013; 144:38-43. [PMID: 23856586 DOI: 10.1016/j.biortech.2013.06.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 05/31/2013] [Accepted: 06/03/2013] [Indexed: 06/02/2023]
Abstract
Hydrolysis of lipids from microalgae under high water content was investigated as a pretreatment of direct esterification. Results indicated that the hydrolysis process reduced the inhibition by water in FAME production; in addition, FAME obtained by esterification of hydrolysates was increased by 181.7% compared to FAME obtained by direct transesterification under the same amount of water content (80%). This method has great potential in terms of biodiesel production from microalgae since it uses no organic solvent, reduces the drying cost and lowers the operating cost compared to any other traditional method.
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Affiliation(s)
- Kenji Takisawa
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
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245
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Khoo HH, Koh CY, Shaik MS, Sharratt PN. Bioenergy co-products derived from microalgae biomass via thermochemical conversion--life cycle energy balances and CO2 emissions. BIORESOURCE TECHNOLOGY 2013; 143:298-307. [PMID: 23810951 DOI: 10.1016/j.biortech.2013.06.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 05/31/2013] [Accepted: 06/03/2013] [Indexed: 06/02/2023]
Abstract
An investigation of the potential to efficiently convert lipid-depleted residual microalgae biomass using thermochemical (gasification at 850 °C, pyrolysis at 550 °C, and torrefaction at 300 °C) processes to produce bioenergy derivatives was made. Energy indicators are established to account for the amount of energy inputs that have to be supplied to the system in order to gain 1 MJ of bio-energy output. The paper seeks to address the difference between net energy input-output balances based on a life cycle approach, from "cradle-to-bioenergy co-products", vs. thermochemical processes alone. The experimental results showed the lowest results of Net Energy Balances (NEB) to be 0.57 MJ/MJ bio-oil via pyrolysis, and highest, 6.48 MJ/MJ for gas derived via torrefaction. With the complete life cycle process chain factored in, the energy balances of NEBLCA increased to 1.67 MJ/MJ (bio-oil) and 7.01 MJ/MJ (gas). Energy efficiencies and the life cycle CO2 emissions were also calculated.
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Affiliation(s)
- H H Khoo
- Institute of Chemical and Engineering Sciences, 1 Pesek Road, Jurong Island, 627833 Singapore.
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246
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Yang S, Guarnieri MT, Smolinski S, Ghirardi M, Pienkos PT. De novo transcriptomic analysis of hydrogen production in the green alga Chlamydomonas moewusii through RNA-Seq. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:118. [PMID: 23971877 PMCID: PMC3846465 DOI: 10.1186/1754-6834-6-118] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 08/05/2013] [Indexed: 05/04/2023]
Abstract
BACKGROUND Microalgae can make a significant contribution towards meeting global renewable energy needs in both carbon-based and hydrogen (H2) biofuel. The development of energy-related products from algae could be accelerated with improvements in systems biology tools, and recent advances in sequencing technology provide a platform for enhanced transcriptomic analyses. However, these techniques are still heavily reliant upon available genomic sequence data. Chlamydomonas moewusii is a unicellular green alga capable of evolving molecular H2 under both dark and light anaerobic conditions, and has high hydrogenase activity that can be rapidly induced. However, to date, there is no systematic investigation of transcriptomic profiling during induction of H2 photoproduction in this organism. RESULTS In this work, RNA-Seq was applied to investigate transcriptomic profiles during the dark anaerobic induction of H2 photoproduction. 156 million reads generated from 7 samples were then used for de novo assembly after data trimming. BlastX results against NCBI database and Blast2GO results were used to interpret the functions of the assembled 34,136 contigs, which were then used as the reference contigs for RNA-Seq analysis. Our results indicated that more contigs were differentially expressed during the period of early and higher H2 photoproduction, and fewer contigs were differentially expressed when H2-photoproduction rates decreased. In addition, C. moewusii and C. reinhardtii share core functional pathways, and transcripts for H2 photoproduction and anaerobic metabolite production were identified in both organisms. C. moewusii also possesses similar metabolic flexibility as C. reinhardtii, and the difference between C. moewusii and C. reinhardtii on hydrogenase expression and anaerobic fermentative pathways involved in redox balancing may explain their different profiles of hydrogenase activity and secreted anaerobic metabolites. CONCLUSIONS Herein, we have described a workflow using commercial software to analyze RNA-Seq data without reference genome sequence information, which can be applied to other unsequenced microorganisms. This study provided biological insights into the anaerobic fermentation and H2 photoproduction of C. moewusii, and the first transcriptomic RNA-Seq dataset of C. moewusii generated in this study also offer baseline data for further investigation (e.g. regulatory proteins related to fermentative pathway discussed in this study) of this organism as a H2-photoproduction strain.
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Affiliation(s)
| | | | - Sharon Smolinski
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - Maria Ghirardi
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
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247
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Dillschneider R, Steinweg C, Rosello-Sastre R, Posten C. Biofuels from microalgae: photoconversion efficiency during lipid accumulation. BIORESOURCE TECHNOLOGY 2013; 142:647-54. [PMID: 23777817 DOI: 10.1016/j.biortech.2013.05.088] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 05/21/2013] [Accepted: 05/23/2013] [Indexed: 05/04/2023]
Abstract
The accumulation of storage lipids in oleaginous microalgae can be induced by a targeted nutrient limitation. Experiments with varying concentrations of nitrate in the culture medium showed differing volumetric productivities of Phaeodactylum tricornutum in batch experiments. This was partially attributable to the differentiated ability of cultures to absorb light. Apart from that, it was demonstrated that storage molecule accumulation follows kinetics that show saturation at high photon flux densities. The measurement of the photoconversion efficiency (PCE) based on a rigorous balancing of absorbed light energy and changes in the enthalpy of combustion of biomass during nutrient depletion. In batch experiments the PCE was increased more than twofold, from 2.48% at low nitrate concentrations to a maximum value of 5.65%, by increase of the nitrogen availability.
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Affiliation(s)
- Robert Dillschneider
- Department of Bioprocess Engineering, Institute of Engineering in Life Sciences, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.
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248
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Liu J, Zhu Y, Tao Y, Zhang Y, Li A, Li T, Sang M, Zhang C. Freshwater microalgae harvested via flocculation induced by pH decrease. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:98. [PMID: 23834840 PMCID: PMC3716916 DOI: 10.1186/1754-6834-6-98] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2013] [Accepted: 07/05/2013] [Indexed: 05/20/2023]
Abstract
BACKGROUND Recent studies have demonstrated that microalga has been widely regarded as one of the most promising raw materials of biofuels. However, lack of an economical, efficient and convenient method to harvest microalgae is a bottleneck to boost their full-scale application. Many methods of harvesting microalgae, including mechanical, electrical, biological and chemical based, have been studied to overcome this hurdle. RESULTS A new flocculation method induced by decreasing pH value of growth medium was developed for harvesting freshwater microalgae. The flocculation efficiencies were as high as 90% for Chlorococcum nivale, Chlorococcum ellipsoideum and Scenedesmus sp. with high biomass concentrations (>1g/L). The optimum flocculation efficiency was achieved at pH 4.0. The flocculation mechanism could be that the carboxylate ions of organic matters adhering on microalgal cells accepted protons when pH decreases and the negative charges were neutralized, resulting in disruption of the dispersing stability of cells and subsequent flocculation of cells. A linear correlation between biomass concentration and acid dosage was observed. Furthermore, viability of flocculated cells was determined by Evans Blue assay and few cells were found to be damaged with pH decrease. After neutralizing pH and adding nutrients to the flocculated medium, microalgae were proved to maintain a similar growth yield in the flocculated medium comparing with that in the fresh medium. The recycling of medium could contribute to the economical production from algae to biodiesel. CONCLUSIONS The study provided an economical, efficient and convenient method to harvest fresh microalgae. Advantages include capability of treating high cell biomass concentrations (>1g/L), excellent flocculation efficiencies (≥ 90%), operational simplicity, low cost and recycling of medium. It has shown the potential to overcome the hurdle of harvesting microalgae to promote full-scale application to biofuels from microalgae.
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Affiliation(s)
- Jiexia Liu
- Department of Chemistry, Jinan University, Tianhe District, Guangzhou 510632, China
| | - Yi Zhu
- Department of Chemistry, Jinan University, Tianhe District, Guangzhou 510632, China
| | - Yujun Tao
- Department of Chemistry, Jinan University, Tianhe District, Guangzhou 510632, China
| | - Yuanming Zhang
- Department of Chemistry, Jinan University, Tianhe District, Guangzhou 510632, China
| | - Aifen Li
- Research Center of Hydrobiology, Jinan University, Tianhe District, Guangzhou 510632, China
| | - Tao Li
- Research Center of Hydrobiology, Jinan University, Tianhe District, Guangzhou 510632, China
| | - Ming Sang
- Research Center of Hydrobiology, Jinan University, Tianhe District, Guangzhou 510632, China
| | - Chengwu Zhang
- Research Center of Hydrobiology, Jinan University, Tianhe District, Guangzhou 510632, China
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249
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Abdelaziz AEM, Leite GB, Hallenbeck PC. Addressing the challenges for sustainable production of algal biofuels: I. Algal strains and nutrient supply. ENVIRONMENTAL TECHNOLOGY 2013; 34:1783-805. [PMID: 24350435 DOI: 10.1080/09593330.2013.827748] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Microalgae hold promise for the production of sustainable replacement of fossil fuels due to their high growth rates, ability to grow on non-arable land and their high content, under the proper conditions, of high energy compounds that can be relatively easily chemically converted to fuels using existing technology. However, projected large-scale algal production raises a number of sustainability concerns concerning land use, net energy return, water use and nutrient supply. The state-of-the-art of algal production of biofuels is presented with emphasis on some possible avenues to provide answers to the sustainability questions that have been raised. Here, issues concerning algal strains and supply of nutrients for large-scale production are discussed. Since sustainability concerns necessitate the use of wastewaters for supply of bulk nutrients, emphasis is placed on the composition and suitability of different wastewater streams. At the same time, algal cultivation has proven useful in waste treatment processes, and thus this aspect is also treated in some detail.
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Affiliation(s)
- Ahmed E M Abdelaziz
- Département de microbiologie et immunologie, Université de Montréal, CP 6128, Centre-ville, Montréal, Canada PQ H3C 3J7
| | - Gustavo B Leite
- Département de microbiologie et immunologie, Université de Montréal, CP 6128, Centre-ville, Montréal, Canada PQ H3C 3J7
| | - Patrick C Hallenbeck
- Département de microbiologie et immunologie, Université de Montréal, CP 6128, Centre-ville, Montréal, Canada PQ H3C 3J7
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250
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Abdelaziz AEM, Leite GB, Hallenbeck PC. Addressing the challenges for sustainable production of algal biofuels: II. Harvesting and conversion to biofuels. ENVIRONMENTAL TECHNOLOGY 2013; 34:1807-36. [PMID: 24350436 DOI: 10.1080/09593330.2013.831487] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In order to ensure the sustainability of algal biofuel production, a number of issues need to be addressed. Previously, we reviewed some of the questions in this area involving algal species and the important challenges of nutrient supply and how these might be met. Here, we take up issues involving harvesting and the conversion ofbiomass to biofuels. Advances in both these areas are required if these third-generation fuels are to have a sufficiently high net energy ratio and a sustainable footprint. A variety of harvesting technologies are under investigation and recent studies in this area are presented and discussed. A number of different energy uses are available for algal biomass, each with their own advantages as well as challenges in terms of efficiencies and yields. Recent advances in these areas are presented and some of the especially promising conversion processes are highlighted.
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Affiliation(s)
- Ahmed E M Abdelaziz
- Département de microbiologie et immunologie, Université de Montréal, CP 6128 Centre-Ville, Montréal, Quebec, Canada PQ H3C 3J7
| | - Gustavo B Leite
- Département de microbiologie et immunologie, Université de Montréal, CP 6128 Centre-Ville, Montréal, Quebec, Canada PQ H3C 3J7
| | - Patrick C Hallenbeck
- Département de microbiologie et immunologie, Université de Montréal, CP 6128 Centre-Ville, Montréal, Quebec, Canada PQ H3C 3J7
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