Mass Cultivation Of Microalgae Research Articles

Effect of harvesting methods on the reusability of water for cultivation of Chlorella vulgaris, its lipid productivity and biodiesel quality

The large water footprint is one of the major bottlenecks for the sustainable microalgae-based biorefinery. In order to reduce the amount of water that is needed for mass cultivation of microalgae, the reusability of culture medium for further algal growth was tested. Chlorella vulgaris was cultivated in recycled medium that was obtained from harvesting microalgal cells by using either centrifugation or flocculation with FeCl3 or alum. The present study shows that centrifugation and flocculation with FeCl3 are equally effective (>90%) for harvesting C. vulgaris without any deleterious effects on algal growth when recycled media was used. However, even low concentration (<5ppm) of residual alum was shown to inhibit microalgal growth. More interestingly, the recycled media obtained after centrifugation or flocculation with FeCl3 had a positive effect on biomass and lipid productivity of C. vulgaris. Extracellular substances such as carbohydrate, proteins, or ferric ions in the recycled media appear to cause these positive effects. Furthermore, change of pH to 2–3 and washing with water were found to effectively remove the residual ferric ions that are present in either harvested biomass or biodiesel, respectively. These results suggest that the use of recycled medium for microalgal cultivation is possible, and the choice of harvest methods must be carefully made when the recycling of culture medium is considered for microalgal cultivation.

Open Mass Cultures of Marine Microalgae for Biodiesel Production: Laboratory Approach to Study Species Competition in Mixed Cultures

Since the interspecific competition represents a critical issue for biodiesel production in open mass cultures of microalgae, laboratory studies aimed to select competitive species receive significant interest. In this work, a laboratory approach based on the method of multisizing cell counting was developed to monitor the competition course of single algal species grown in mixed cultures. Two marine microalgae, Dunaliella tertiolecta and Phaeodactylum tricornutum, were used to set-up an induced-contamination assay, with the aim to test their competitive capabilities. The evaluation of the oil production by dried biomass extraction was coupled to the growth assay to investigate the effect of competition on oil yield. The adopted experimental approach revealed effective as a method to selectively measure the algal growth of single species in mixed cultures, enabling to evaluate the competitive properties of Dunaliella outgrowing the contaminant species Phaeodactylum. At the end of the experiment the dominant species contributed more than 90% to the total biomass, while no loss of oil production was observed, the oil yield in the mixed being even higher than in the unialgal culture (3.15 vs. 2.28 mg). The outcomes of the induced competition suggest the use of Dunaliella as a competitive oil-producer species and especially support the potential of the experimental approach to be used for preliminary screening to drive species selection for open mass cultures.

해양배양기 내 중탄산염 공급에 따른 Tetraselmis sp. KCTC12432BP 증식에 관한 연구

The ocean provide great benefits for microalgal mass cultures with maintaining stable temperature due to high specific heat, mixing by wave energy, and providing large area for large-scale microalgae cultures. In this study, we cultivated a marine green microalga, Tetraselmis sp. KCTC12432BP, using marine photobioreactors on the ocean for investigating the effect of NaHCO₃ concentration on the biomass productivities and evaluating the potential of ocean microalgae culture. The culture medium consist of three fold concentrated f/2-Si with 4 g/L of NaHCO3, which is dissolved in natural seawater. After 11 days of cultivation, the cultures reached stationary phase at biomass concentration of 1.6 g/L. At that time, NaHCO₃ concentration of 0, 2, and 4 g/L were fed to the cultures. The daily productivities of 0.11, 0.19, 0.30 g/L/day were attained with feeding rate of 0, 2, and 4 g/L NaHCO₃, respectively. Biomass productivity of Tetraselmis sp. KCTC12432BP was a function of the NaHCO₃ feeding rate as expected. This research shows that the microalgae can grow with NaHCO₃ as carbon source in marine photobioreactors on the ocean while exploiting various benefits of ocean cultivation.

Hydrothermal gasification of Acutodesmus obliquus for renewable energy production and nutrient recycling of microalgal mass cultures

Hydrothermal gasification is a process which uses any biomass or carbon-containing source as substrate to generate biogas of regenerative energy production. We used microalgae as biomass source and evaluated the potential of using the residual water of the conversion process as recycled nutrient source for cultivation of microalgae. Nutrient recycling was tested by monitoring growth of Acutodesmus obliquus and Chlorella vulgaris on residual water from hydrothermal gasification of A. obliquus. Four different gasification set ups were tested. After the procedure, all obtained liquid nutrient phases contained, beside nutrients, growth-inhibiting substances affecting photosynthetic activity and biomass yield of the two algal species. At least 28 potential toxic substances were found within one of the batches. Phytotoxicity on cellular structure was verified by electron microscopy. The cell form remained intact but cell compartments vanished. C. vulgaris was not able to recover to a vital growing organism during cultivation, whereas A. obliquus was able to restore cell compartments, photosynthetic activity and growth after 3 days of cultivation. A 355-fold dilution, UV treatment for 4 h and activated carbon filtration of the residual water from gasification finally enabled the discharge to support microalgal growth. UV treatment eliminated 23 substances but generated 4 new substances that were not detected before treatment. Activated carbon filtration eliminated 26 substances. Growth of microalgae obtained in the treated residual water was comparable with that in control medium. This study demonstrated the possibility to recover nutrients after the hydrothermal gasification process when the discharge got remediated to restart the value adding chain of microalgae and lower additional nutrient supply for microalgal cultivation.

Two-stage cultivation of a Nannochloropsis mutant for biodiesel feedstock

Optimization of mass microalgae cultures is required for the efficient production of biodiesel feedstock in terms of total fatty acid (TFA) content and a conducive fatty acid profile. A mutant strain of Nannochloropsis sp. (MT-I5), as modified via random mutagenesis and flow cytometric cell sorting, was investigated in both a single- and two-stage cultivation using 250 L laboratory raceway ponds. Culture was based on photoautotrophic biomass production (stage 1) followed by a switch to photomixotrophic growth induced by adding sodium acetate (2 mM) (stage 2). The biomass yield of the mutant in two-stage cultivation was maintained at a level similar to that of the one-stage photoautotrophic culture, but TFA content was increased by 2.3-fold. The fatty acid profile of MT-I5 also had an increased level of desirable saturated fatty acids (SFA) for use as a biodiesel feedstock, i.e. from 43 to 48 % of TFA, as well as a decreased level of less desirable polyunsaturated fatty acids (PUFA), i.e. from 22 to 7 % of TFA. The two-stage cultivation process is of interest for the mass culture of microalgae for biofuel feedstocks, as biomass productivity can be maximized during the first stage of culture until N-starvation is achieved, followed by the enhanced synthesis of SFA in the second stage of culture by adding sodium acetate as a fixed-carbon source.

Introduction

AB Aquatic Biology Contact the journal Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AB 22:1-4 (2014) - DOI: https://doi.org/10.3354/ab00613 Theme Section: Environmental forcing of aquatic primary productivity Introduction F. L. Figueroa1, J. M. Mercado2, J. Beardall3,*, P. J. Neale4, V. Montecino5, J. C. Kromkamp6 1Department of Ecology, Faculty of Sciences, University of Málaga, 29071 Málaga, Spain 2Spanish Institute of Oceanography, 29640 Fuengirola, Spain 3School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia 4Smithsonian Environmental Research Center, Edgewater, Maryland 21037, USA 5Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile 6Royal Netherlands Institute for Sea Research, PO Box 140, 4400 AC Yerseke, The Netherlands *Corresponding author: john.beardall@monash.edu ABSTRACT: Earth is currently experiencing rapid changes in climate, associated with anthropogenic activities, which have the potential to have significant effects on aquatic ecosystems. The 9th International Workshop of the Group for Aquatic Primary Productivity (GAP9) assessed the effects of environmental factors on physiological performance and primary productivity of micro- and macroalgae. This Introduction summarizes the activities and main findings of the 4 workgroups of GAP9 as published in this Theme Section of Aquatic Biology. KEY WORDS: Alboran Sea · Macroalgae · Microalgal mass culture · Nutrients · Ocean acidification · Phytoplankton · Primary productivity · Ultraviolet radiation Full text in pdf format NextCite this article as: Figueroa FL, Mercado JM, Beardall J, Neale PJ, Montecino V, Kromkamp JC (2014) Introduction. Aquat Biol 22:1-4. https://doi.org/10.3354/ab00613 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AB Vol. 22. Online publication date: November 20, 2014 Print ISSN: 1864-7782; Online ISSN: 1864-7790 Copyright © 2014 Inter-Research.

Photosynthesis monitoring to optimize growth of microalgal mass cultures: application of chlorophyll fluorescence techniques

Since the mid-1990s, chlorophyll a (chl a) fluorescence measurement has become widespread to monitor photosynthetic performance of microalgal mass cultures. This paper aims to provide practical instructions for microalgal physiologists and biotechnologists on how fluores- cence monitoring can be used to explain changes in photosynthetic activity of microalgal mass cultures. Emphasis is placed on the 2 most common fluorescence techniques—pulse-amplitude- modulation and fluorescence induction kinetics—and the interpretation of important variables that reflect changes of photosynthesis and physiological status of microalgal cultures. In particu- lar, consideration is given to problems associated with the estimation of the photochemical yield of photosystem II and its relationship to linear electron transport rate and overall photosynthesis. Emphasis is also given to the applications and limitations of these techniques through several case studies. In model experiments with microalgal cultures, typical records and their interpretation under various culture conditions are illustrated. Changes of photosynthetic activity and selected variables monitored by chl a fluorescence techniques can thus be related to changes of cultivation conditions, physiological status and growth of microalgal cultures for a given microalgal strain and cultivation system. In this way, chl a fluorescence may be used as a rapid screening technique to monitor photosynthetic activity and subsequently to estimate growth rate in both indoor and outdoor studies. This text and results formed the basis of a key lecture at the 9 th International GAP workshop held at the University of Malaga in September 2012.

Hydrodynamics and photosynthesis performance of Chlorella fusca (Chlorophyta) grown in a thin-layer cascade (TLC) system

The thin-layer cascade (TLC) system is an open system for microalgae cultivation composed of a retention tank connected by pump and pipes to a horizontal exposed area that con- sists of an upper basin and a TLC. Light and hydrodynamics are different among compartments, so overall photosynthetic activity can be influenced by the retention time of the cells in each com- partment. We established 2 settings with different retention times in the cascade and tank to com- pare the photosynthetic activity of Chlorella fusca (Chlorophyta) among compartments. Changes in the retention time were achieved using 2 layer thicknesses in the cascade: 8 and 18 mm. Reten- tion time in the cascade represented about 16 and 34% of the duration of a whole system cycle when H1 (8 mm thickness) and H2 (18 mm thickness) units, respectively, were used. These reten- tion periods were lower than those in the tank (67 and 49%, respectively) but higher than those in the basin (12% for both H1 and H2). Photosynthetic activity was measured in situ as relative elec- tron transport rate (rETR) using a pulse-amplitude modulated fluorometer. In both setups, the highest rETR was reached in the cascade. The increase of the layer thickness was a good option to avoid photoinhibition. We suggest estimating the mean rETR of the whole system considering the retention time, since it can better reflect overall growth because it takes into account the time that the cells spend in each compartment. These results are useful for optimization of photo - synthetic activity and growth of outdoor microalgae mass cultures in TLCs for biotechnological purposes.

A cost analysis of microalgal biomass and biodiesel production in open raceways treating municipal wastewater and under optimum light wavelength.

Open raceway ponds are cost-efficient for mass cultivation of microalgae compared with photobioreactors. Although low-cost options like wastewater as nutrient source is studied to overcome the commercialization threshold for biodiesel production from microalgae, a cost analysis on the use of wastewater and other incremental increases in productivity has not been elucidated. We determined the effect of using wastewater and wavelength filters on microalgal productivity. Experimental results were then fitted into a model, and cost analysis was performed in comparison with control raceways. Three different microalgal strains, Chlorella vulgaris AG10032, Chlorella sp. JK2, and Scenedesmus sp. JK10, were tested for nutrient removal under different light wavelengths (blue, green, red, and white) using filters in batch cultivation. Blue wavelength showed an average of 27% higher nutrient removal and at least 42% higher chemical oxygen demand removal compared with white light. Naturally, the specific growth rate of microalgae cultivated under blue wavelength was on average 10.8% higher than white wavelength. Similarly, lipid productivity was highest in blue wavelength, at least 46.8% higher than white wavelength, whereas FAME composition revealed a mild increase in oleic and palmitic acid levels. Cost analysis reveals that raceways treating wastewater and using monochromatic wavelength would decrease costs from 2.71 to 0.73 $/kg biomass. We prove that increasing both biomass and lipid productivity is possible through cost-effective approaches, thereby accelerating the commercialization of low-value products from microalgae, like biodiesel.

Antenna size reduction as a strategy to increase biomass productivity: a great potential not yet realized

A major limitation in achieving high photosynthetic efficiency in microalgae mass cultures is the fact that the intensity of direct sunlight greatly exceeds the photosynthetic capacity of the cells. Due to the high pigment content of algal cells, the light absorption rate surpasses the much slower conversion rate to biochemical energy. The excess of light energy is predominantly dissipated as heat, decreasing the light use efficiency of the culture. Algae with a truncated antenna system could substantially increase biomass productivity of mass cultures because oversaturation of the photosystems and concomitant dissipation of light energy are minimized. In this study, we measured the areal biomass productivity of wild-type strain cultures and four promising antenna size mutant cultures of Chlamydomonas reinhardtii. This was performed under simulated mass culture conditions. The strains were cultivated in turbidostat controlled lab-scale panel photobioreactors at an incident light intensity of 1500 μmol photons m−2 s−1. The mutant cultures did not exhibit the expected higher productivity. The greatest mutant culture productivity values were approximate to those of the wild-type productivity of 1.9 g m−2 h−1. The high sensitivity to abrupt light shifts indicated that the mutant cultures experienced reduced fitness and higher susceptibility to photodamage. This can possibly be explained by impaired photoprotection mechanisms induced by the antenna complex alterations, or by unintended side effects of the genetic modifications. Still, if these effects could be eliminated, the principle of antenna size reduction is a promising strategy to increase productivity. Selection criteria for the future creation of antenna size mutants should, therefore, include tolerance to high light conditions.

Cultivation of Chlorella sp. IM-01 in municipal wastewater for simultaneous nutrient removal and energy feedstock production

Current study assesses the potential of indigenously isolated microalgae Chlorella sp. IM-01 for nutrients removal from sewage wastewater and also usability of this wastewater for mass cultivation of microalgae for biofuels production. Growth of Chlorella sp. IM-01 is studied in BG-11 nutrient media and wastewater samples (inlet and outlet from primary treatment point designated as S1 and S2, respectively) at the retention period of 4th and 10th day. In wastewater samples, better growth rate is found in S2 as compared to S1. Biochemical analysis in terms of carbohydrates, proteins and lipids is also done at 4th and 10th day. Biochemical analysis revealed that S2 has better prospect for biofuel production and retention period of 4–5 days is sufficient. These finding suggest that use of such potential species not only prove to deplete the water pollution levels but also act as energy feedstock for biofuels production.

Use of orange peel extract for mixotrophic cultivation of Chlorella vulgaris: Increased production of biomass and FAMEs

Mass cultivation of microalgae is necessary to achieve economically feasible production of microalgal biodiesel, but the high cost of nutrients is a major limitation. In this study, orange peel extract (OPE) was used as an inorganic and organic nutrient source for the cultivation of Chlorella vulgaris OW-01. Chemical composition analysis of the OPE indicated that it contains sufficient nutrients for mixotrophic cultivation of C. vulgaris OW-01. Analysis of biomass and FAME production showed that microalgae grown in OPE medium produced 3.4-times more biomass and 4.5-times more fatty acid methyl esters (FAMEs) than cells cultured in glucose-supplemented BG 11 medium (BG-G). These results suggest that growth of microalgae in an OPE-supplemented medium increases lipid production and that OPE has potential for use in the mass cultivation of microalgae.

Improving the sunlight-to-biomass conversion efficiency in microalgal biofactories

Microalgae represent promising organisms for the sustainable production of commodities, chemicals or fuels. Future use of such systems, however, requires increased productivity of microalgal mass cultures in order to reach an economic viability for microalgae-based production schemes. The efficiency of sunlight-to-biomass conversion that can be observed in bulk cultures is generally far lower (35–80%) than the theoretical maximum, because energy losses occur at multiple steps during the light-driven conversion of carbon dioxide to organic carbon. The light-harvesting system is a major source of energy losses and thus a prime target for strain engineering. Truncation of the light-harvesting antenna in the algal model organism Chlamydomonas reinhardtii was shown to be an effective way of increasing culture productivity at least under saturating light conditions. Furthermore engineering of the Calvin–Benson cycle or the creation of photorespiratory bypasses in A. thaliana proved to be successful in terms of achieving higher biomass productivities. An efficient generation of novel microalgal strains with improved sunlight conversion efficiencies by targeted engineering in the future will require an expanded molecular toolkit. In the meantime random mutagenesis coupled to high-throughput screening for desired phenotypes can be used to provide engineered microalgae.

Internal deoxygenation of tubular photobioreactor for mass production of microalgae by perfluorocarbon emulsions

BACKGROUND With the increasing demand for microalgae it is clear that new industrial culturing techniques are needed. Current microalgae growth is done either in open or closed systems. In various situations, it has been reported that closed systems offer many advantages over open systems including lower contamination and better control over operating parameters. However, in industrial scale-up of closed tubular photobioreactors, hypercritical oxygen concentration is one of the dominating detrimental factors limiting the mass culture of microalgae in tubular systems. However, published accounts on alleviating oxygen stress imposed on large-scale tubular photobioreactors are scarce. RESULTS Results from this work showed that perfluorocarbon (PFC) emulsions, acting as gas-carrier vehicles, increased algal photosynthesis and biomass at least 4-fold in a closed tubular photobioreactor by decreasing dissolved oxygen concentration from 47% (generated in the photobioreactor without using PFC emulsions) to 4% after 9 days of culture. CONCLUSION In order to tackle the problem of high concentrations of dissolved oxygen strongly inhibiting microalgal biomass production, an innovative methodology has been developed which involves gradually supplying carbon dioxide and removing the accumulated oxygen through the use of PFC emulsions. © 2014 Society of Chemical Industry

Mixotrophic cultivation of green microalgae Scenedesmus obliquus on cheese whey permeate for biodiesel production

Microalgae mass cultivation for biodiesel production might very well become the next marketable biofuel. The main challenge to overcome however is the development of high efficiency strategies for the large-scale production of oleaginous microalgae at low costs. In the present work, the use of cheese whey permeate (WP) in mixotrophic microalgae cultures is proposed. Pure lactose, the main constituent of WP (>80% w/w of the total dissolved solids), can support Scenedesmus growth under heterotrophic culture conditions (absence of light). Substituting 40% (v/v) of the culture medium with WP significantly stimulates Scenedesmus obliquus growth under mixotrophic (μmax=1.083±0.030day−1) and heterotrophic (μmax=0.702±0.025day−1) conditions, compared to photoautotrophic control cultures (μmax=0.267±0.083day−1). As growth occurs in the presence of lactose, a significant reduction of its concentration is observed, while the galactose and glucose concentrations actually increase in the culture medium. Culture medium analyses showed complete exhaustion of extracellular nitrogen (nitrate and ammonium), while intracellular lipid analyses showed neutral lipid (NL) accumulation, particularly under conditions of high pH (>9.5). Photoautotrophic control cultures accumulated more lipids (per dry weight) than WP-supplemented cultures, an aspect which is discussed in the context of lipid enrichment strategies. A fast and simple method for NL cellular content estimation is also described.

Microbiome analysis of a microalgal mass culture growing in municipal wastewater in a prototype OMEGA photobioreactor

Large-scale cultivation of microalgae for biofuels may avoid competing for agriculture, water, and fertilizer by using wastewater and avoid competing for land by using the Offshore Membrane Enclosures for Growing Algae (OMEGA) system. Some microalgae thrive in wastewater; however, wastewater also contains a complex mixture of organisms. An algae culture in wastewater from a San Francisco Treatment Facility in a 1600-L OMEGA culture system was monitored by standard methods. Prima facie evidence of a chytrid infection prompted a detailed investigation of the microbiome over a 13-day period using second generation sequencing of hypervariable regions of the small subunit rRNA genes. The observed bacteria, initially dominated by γ-proteobacteria, shifted to Cytophagia, Flavobacteriia, and Sphingobacteriia after addition of exogenous nutrients. The dominant algae genera introduced with the inoculum, Desmodesmus and Scenedesmus, remained over 70% of the sequence reads on day 13, although the optical density and fluorescence of the culture declined. Nonalgal eukarya, initially dominated by unclassified alveolates, chrysophytes, and heliozoan grazers, shifted to chytrid fungi on day 5 and continued to day 13. The results of this microbiome analysis can facilitate the development of probe or primer based surveillance systems for routine monitoring of large-scale microalgae cultures.

Molecular diagnostics for monitoring contaminants in algal cultivation

There is currently great interest in mass cultivation of microalgae for production of fuels and other high value products. Since algae have not previously been grown at the scales and with the precision required for these endeavors, sensitive methods are needed for enumeration of elite algal varieties relative to “weedy” invader strains that are ubiquitous in the environment and a common issue with culture management. The ideal monitoring strategy would be inexpensive and identify weedy algae long before they become prominent in cultures of elite varieties. Herein, multiple polymerase chain reaction (PCR)-based tools for monitoring contaminants are presented. These include resources to identify unknown strains, to routinely monitor dominant constituents in cultures, and to detect contaminants constituting as little as one in 108 cells in a culture. Quantitative PCR was shown to be 104 times more sensitive for detecting weeds than flow cytometry. During characterization of these tools, it was demonstrated that contamination is a common phenomenon and that early detection is necessary for informed decision making during culture selection for subculturing or scale-up. Thus, implementation of strategies for monitoring contaminants in algal cultivation is a critical component of culture management for optimal productivity.

Development of a low cost medium for Tetraselmis sp. growth and biochemical profile improvement

Event Abstract Back to Event Development of a low cost medium for Tetraselmis sp. growth and biochemical profile improvement Catarina Rosado Correia1*, Inês Póvoa2, Daniel F. Marques1, Carla Tecelão1, Victória Del Pino2 and Sérgio Miguel Leandro1 1 GIRM -Group of Investigation on Marine Resources, School of Tourism and Marine Technology, Campus 4 - Polytechnic Institute of Leiria, Portugal 2 Necton, S.A. - Portuguese Marine Cultures: Microalgae business Unit, Belamandil, Portugal In aquaculture, food quality improvement – especially microalgae – is mandatory. Despite having many applications in this industry, few genera of microalgae are actively used and exploited, mainly because of its lack of requirements, such as digestibility, size and lack of toxicity. Tetraselmis sp. is one of the most commonly used microalgae on aquaculture. Despite their nutritional profile, this is a highly demanding industry that requires constant improvement concerning cost production and productivity, and a biochemical profile for end usage. Improvements can be achieved through culture condition manipulation, changing, for instance, culture media’s composition. In order to achieve better biochemical profiles, productivity and lower production costs, three mediums were tested – NutriBloom [NB] (commercial medium used at Necton’s facilities), Simplex [S] (no addition of iron or any micronutrient) and Sea Mineral Solution [SMS], and Tetraselmis’s level of protein, carbohydrates, total lipid and PUFA’s profile were controlled at logarithmic and stationary phase, using classical techniques, according to Lowry (1951), Dubois (1956), Bligh and Dyer (1959) and Lepage & Roy (1986). SMS revealed better results than the others, achieving higher cell numbers, productivity and less duplication time. In logarithmic phase, this medium also had the higher lipid and PUFAs percentage. S medium showed higher protein content. In stationary phase, NB medium presented more proteins, lipid and sugars. S medium had better PUFAs percentage. Differences between micronutrient concentrations explain the verified variations in microalgae’s biochemical profile, developing a low-cost medium for Tetraselmis sp. culture. Keywords: Aquaculture, Biochemical profile, micronutrient, PUFA, Microalgae mass cultivation, Tetraselmis sp. Conference: IMMR | International Meeting on Marine Research 2014, Peniche, Portugal, 10 Jul - 11 Jul, 2014. Presentation Type: Poster Presentation Topic: BLUE BIOTECH Citation: Rosado Correia C, Póvoa I, Marques DF, Tecelão C, Del Pino V and Leandro S (2014). Development of a low cost medium for Tetraselmis sp. growth and biochemical profile improvement. Front. Mar. Sci. Conference Abstract: IMMR | International Meeting on Marine Research 2014. doi: 10.3389/conf.fmars.2014.02.00049 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 10 May 2014; Published Online: 18 Jul 2014. * Correspondence: Dr. Catarina Rosado Correia, GIRM -Group of Investigation on Marine Resources, School of Tourism and Marine Technology, Campus 4 - Polytechnic Institute of Leiria, 2520–641 Peniche, Portugal, catarinasrcorreia@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Catarina Rosado Correia Inês Póvoa Daniel F Marques Carla Tecelão Victória Del Pino Sérgio Miguel Leandro Google Catarina Rosado Correia Inês Póvoa Daniel F Marques Carla Tecelão Victória Del Pino Sérgio Miguel Leandro Google Scholar Catarina Rosado Correia Inês Póvoa Daniel F Marques Carla Tecelão Victória Del Pino Sérgio Miguel Leandro PubMed Catarina Rosado Correia Inês Póvoa Daniel F Marques Carla Tecelão Victória Del Pino Sérgio Miguel Leandro Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Integration of greenhouse gas reduction and algae bio-energy technology

Biofuels can be obtained from a variety of sources, and microalgaes are of particular interest as one of the most promising sources of biomass for biofuels. In this review, the potential and problem of microalgae bio-energy are analyzed, which indicates that the mode of mass cultivation of microalgae, including improving the growth of microalgae, reducing the energy consumption and enhancing the reliability of mass cultivation of microalgae, is still the main task. Here we introduced the strategy to integrate microalgae bio-energy technology with greenhouse gas reduction in SINOPEC. Besides, the key technologies employed in microalgae bio-energy and the on-going projects of utilizing greenhouse gases to develop microalgae bio-energy in Sinopec Shijiazhuang Refining and Chemical Company, including isolation and characterization of microalgae species, photobioreactors and application of microalgae biomass, are described.

Mass cultivation of microalgae and extraction of total hydrocarbons: A kinetic and thermodynamic study

In this present investigation, the biofuel alga Botryococcus braunii (B. braunii) was mass cultivated in 10m2 open raceway pond at batch mode. This study was mainly focused on the kinetics and thermodynamics approach for total lipid and hydrocarbon extraction. At batch mode cultivation the alga produced highest dry biomass of 23gm−2d−1. The algal cells were harvested by autoflocculation method and dried. Different pre-treatment methods, solvents systems and optimization of extraction parameters were carried out in the dry biomass containing moisture less than 1wt%. This reveals ultrasonication combined with chloroform: methanol, extracted maximum of 24.2wt% total lipid and hydrocarbon. Temperature effects (308–338K) on kinetics were investigated. The extraction follows first order kinetics and their rate constants and activation energy were determined as 3.0431s−1and 36.7214kJmol−1 respectively. Thermodynamic activation parameters ΔG≠, ΔH≠ and ΔS≠ were measured, which suggest that the process was endothermic, irreversible and spontaneous.