Elevated atmospheric CO<sub>2</sub> concentration and diurnal cycle induce changes in lipid composition in <i>Arabidopsis thaliana</i>

Ekman, Åsa; Bülow, Leif; Stymne, Sten

doi:10.1111/j.1469-8137.2007.02027.x

Cited by 36 publications

(33 citation statements)

References 54 publications

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“…The relative composition of microalgal lipids depends greatly on the species used and the nutrient, environmental, and developmental conditions in which the cells are cultured and harvested. It has been reported that the composition of microalgal lipids varies considerably with the growth cycle, under nutrient limitation and during a diurnal light dark cycle (Sukenik and Carmeli 1990;Ekman et al 2007). For example, Nannochloropsis sp.…”

Section: Biodieselmentioning

confidence: 99%

“…The traditional wastewater treatment ponds can be modified by creating a controlled anaerobic environment such as a covered pond or tank which allows the methane to be captured and combusted for energy production. In the biochemical process of anaerobic digestion, the waste goes through three steps namely hydrolysis, fermentation and methanogenesis as it is converted to methane (Metcalf and Eddy 2003). Anaerobic digestion is a very effective process for biological oxygen demand removal but it is not an effective way to remove nutrients.…”

Section: Biomethanementioning

confidence: 99%

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Microalgae as second generation biofuel. A review

Singh¹,

Dhar²

2011

Agron. Sustain. Dev.

155

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Microalgae are autotrophic microorganisms having extremely high photosynthetic efficiency and are valued as rich source of lipids, hydrocarbons, and other complex oils for biodiesel besides being an invaluable source of bioethanol, biomethane, and biohydrogen. Biodiesel produced from oilseed crops such as jatropha and soy have lower yields per unit land area and threaten food security. Indeed, microalgae have higher oil yields amounting to about 40 times more oil per unit area of land in comparison to terrestrial oilseed crops such as soy and canola. Further, microalgae production does not require arable land for cultivation. Biofuel is regarded as a proven clean energy source and several entrepreneurs are attempting to commercialize this renewable source. Technology for producing and using biofuel has been known for several years and is frequently modified and upgraded. In view of this, a review is presented on microalgae as second generation biofuel. Microalgal farming for biomass production is the biggest challenge and opportunity for the biofuel industry. These are considered to be more efficient in converting solar energy into chemical energy and are amongst the most efficient photosynthetic plants on earth. Microalgae have simple cellular structure, a lipid-rich composition, and a rapid rate of reproduction. Many microalgal strains can be grown in saltwater and other harsh conditions. Some autotrophic microalgae can also be converted to heterotrophic ones to accumulate high quality oils using organic carbon. However, there are several technical challenges that need to be addressed to make microalgal biofuel profitable. The efficiency of microalgal biomass production is highly influenced by environmental conditions, e.g., light of proper intensity and wavelength, temperature, CO 2 concentration, nutrient composition, salinities and mixing conditions, and by the choice of cultivation systems: open versus closed pond systems, photobioreactors. Currently, microalgae for commercial purpose are grown mostly in open circular/elongated "raceway" ponds which generally have low yields and high production costs. However, a hybrid system combining closed photobioreactor and open pond is a better option. The biggest hurdle in commercialization of microalgal biofuel is the high cost and energy requirement for the microalgal biomass production, particularly agitation, harvesting, and drying of biomass. In order to conserve energy and reduce costs, algae are often harvested in a two-step process involving flocculation followed by centrifugation, filtration, or micro-straining to get a solid concentration. However, the major bottlenecks in algal biodiesel production within the cell can be identified and handled by adopting a system approach involving transcriptomics, proteomics, and metabolomics. Research and developments in the field of new materials and advanced designs for cultivation in closed bioreactors, use of waste water for biomass production, screening of efficient strains, high-value coproduct strategy,...

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Section: Biodieselmentioning

confidence: 99%

Section: Biomethanementioning

confidence: 99%

Microalgae as second generation biofuel. A review

Singh¹,

Dhar²

2011

Agron. Sustain. Dev.

155

View full text Add to dashboard Cite

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“…The relative composition of algal lipids depends greatly on the species used and the nutrient, environmental and developmental conditions in which the cells are cultured and harvested. For example, it has been shown that the composition of algal lipids varies considerably with the growth cycle, under nutrient limitation and during a diurnal light dark cycle (Shifrin & Chisholm 1981;Cho & Thompson 1986;Sukenik & Carmeli 1990;Ekman et al 2007). It remains to be seen how the composition of the lipids affects the efficiency of biofuel conversion.…”

Section: Types and Function Of Lipids In Microalgaementioning

confidence: 99%

Placing microalgae on the biofuels priority list: a review of the technological challenges

Greenwell

Laurens

Shields

et al. 2009

J. R. Soc. Interface.

721

359

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Microalgae provide various potential advantages for biofuel production when compared with 'traditional' crops. Specifically, large-scale microalgal culture need not compete for arable land, while in theory their productivity is greater. In consequence, there has been resurgence in interest and a proliferation of algae fuel projects. However, while on a theoretical basis, microalgae may produce between 10-and 100-fold more oil per acre, such capacities have not been validated on a commercial scale. We critically review current designs of algal culture facilities, including photobioreactors and open ponds, with regards to photosynthetic productivity and associated biomass and oil production and include an analysis of alternative approaches using models, balancing space needs, productivity and biomass concentrations, together with nutrient requirements. In the light of the current interest in synthetic genomics and genetic modifications, we also evaluate the options for potential metabolic engineering of the lipid biosynthesis pathways of microalgae. We conclude that although significant literature exists on microalgal growth and biochemistry, significantly more work needs to be undertaken to understand and potentially manipulate algal lipid metabolism. Furthermore, with regards to chemical upgrading of algal lipids and biomass, we describe alternative fuel synthesis routes, and discuss and evaluate the application of catalysts traditionally used for plant oils. Simulations that incorporate financial elements, along with fluid dynamics and algae growth models, are likely to be increasingly useful for predicting reactor design efficiency and life cycle analysis to determine the viability of the various options for largescale culture. The greatest potential for cost reduction and increased yields most probably lies within closed or hybrid closed -open production systems.

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“…Biomass productivity in outdoor ponds is presented in Table 2 and has been adapted from a review by Griffiths and Harrison (2009 Lipids are abundant in many algae. Lipids and fatty acids serve as key components for cell membranes in plants and algae as well as being important for chemical signaling and energy storage (Ekman et al 2007). Environmental factors such as temperature, light cycles, and nutrient deprivation can influence the capacity for lipid synthesis (Roessler 1988;Shirffrin and Chisholm 1981;Sukenik et al 1989).…”

Section: Composition and Oil Contentmentioning

confidence: 99%

Algal Supply System Design - Harmonized Version

Abodeely¹,

Stevens²,

Ray³

et al. 2013

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The objective of this design report is to provide an assessment of current technologies used for production, dewatering, and converting microalgae cultivated in open-pond systems to biofuel. The original draft design was created in 2011 and has subsequently been brought into agreement with the DOE harmonized model. The design report extends beyond this harmonized model to discuss some of the challenges with assessing algal production systems, including the ability to (1) quickly assess alternative algal production system designs, (2) assess spatial and temporal variability, and (3) perform large-scale assessments considering multiple scenarios for thousands of potential sites. The Algae Logistics Model (ALM) was developed to address each of these limitations of current modeling efforts to enable assessment of the economic feasibility of algal production systems across the United States. The (ALM) enables (1) dynamic assessments using spatiotemporal conditions, (2) exploration of algal production system design configurations, (3) investigation of algal production system operating assumptions, and (4) trade-off assessments with technology decisions and operating assumptions. The report discusses results from the ALM, which is used to assess the baseline design determined by harmonization efforts between U.S. DOE national laboratories. Productivity and resource assessment data is provided by coupling the ALM with the Biomass Assessment Tool developed at PNNL. This high-fidelity data is dynamically passed to the ALM and used to help better understand the impacts of spatial and temporal constraints on algal production systems by providing a cost for producing extracted algal lipids annually for each potential site. Expected OutcomeThe expected outcome of the design report is to provide an update on current technologies and methods for cultivating, dewatering, and converting microalgae into biofuel. In addition, assessments of these technologies within an algal production system are performed using the ALM with data provided by the Biomass Assessment Tool. This computational modeling approach enables the ability to seamlessly integrate technologies being built across the BETO research platform and the broader research community while using high-fidelity data from each potential site to explore design configurations and Technical Memorandum2 of 35 operational assumptions that make biofuels produced from microalgae a viable option. The harmonized baseline design determined by the national laboratories serves as a starting point for exploring alternative algal production system designs and operation. ProgressThe previous algae design report was updated to discuss numerous technologies for cultivating, dewatering, and converting microalgae to biofuels. The harmonized baseline design for large-scale open-pond microalgae production systems is assessed using a computational approach that enables coupling of disparate datasets and models. Baseline performance and costs for algal production systems are characterized in terms o...

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Elevated atmospheric CO₂ concentration and diurnal cycle induce changes in lipid composition in Arabidopsis thaliana

Cited by 36 publications

References 54 publications

Microalgae as second generation biofuel. A review

Microalgae as second generation biofuel. A review

Placing microalgae on the biofuels priority list: a review of the technological challenges

Algal Supply System Design - Harmonized Version

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Elevated atmospheric CO2 concentration and diurnal cycle induce changes in lipid composition in Arabidopsis thaliana

Cited by 36 publications

References 54 publications

Microalgae as second generation biofuel. A review

Microalgae as second generation biofuel. A review

Placing microalgae on the biofuels priority list: a review of the technological challenges

Algal Supply System Design - Harmonized Version

Contact Info

Product

Resources

About

Elevated atmospheric CO₂ concentration and diurnal cycle induce changes in lipid composition in Arabidopsis thaliana