Determination of Optimum Iron Requirement for Production of Microalgae Biomass as Biofuel Feedstock

Microalgae biomass is considered as one of the promising alternative feedstock for biofuel production. The biomass productivity of some of the microalgae can exceed an order of magnitude compared to any other terrestrial plant. Apart from nitrogen and phosphorus, iron is one of the major elements that must be provided to microalgae culture for high density biomass production. The amount of iron that is required per cell or per unit of microalgae biomass will vary among microalgae strains. Depending on the concentration of iron in the cultivation media, the microalgae will accumulate different amount of iron and this process may alter the compositions of other major metabolites. In order to be competitive the cost of microalgae biomass production should be lower and the desired metabolites should be present in higher percentages; therefore, the appropriate concentration of iron should be determined. On the contrary, there are very limited study on the microalgal iron requirement. The first objective of this study is to determine the minimum concentration of iron requirement by some of the locally isolated potential microalgae. The second objective of this study is to characterize the lipid accumulation under different iron concentrations. Gillard f/2 and BG-11 are the two common nutrients composition used to culture marine and freshwater microalgae respectively. In these two nutrients media, the concentrations of iron are 0.65 mg/l and 1.24 mg/l for Guillard F/2 and BG-11 media respectively. Due to some limitations, in most of the cases the concentrations of phototrophic microalgae in large scale biomass production doesn't exceed 0.5 g/L. If these two media are to be used in large scale, iron requirement can be calculated as 1.3 kg (6.3 kg as FeCl3.6H2O) and 2.4 kg (12 kg as FeCl3.6H2O) respectively for each ton of biomass production. Therefore, the cost of the iron fertilizer can be significant for low cost feedstock; furthermore, if there is residual iron in the discharge water it will require additional treatment steps. Three local marine microalgae (Nannochloris sp., Tetraselmis sp., Chlorocystis sp.) and three local freshwater microalgae (Scenedesmous sp., Chlorella sp., Neochloris sp.) were selected to study their iron requirement. Apart from iron, all the nutrients were added as per f/2 or BG-11 media concentrations. However, for the marine microalgae, the range of iron concentration was 0 to 1 mg/L while for the freshwater microalgae it was 0 to 3 mg/L. All the experiments were conducted in triplicates. 10 ml of culture was inoculated in 90 ml containing any culture media in a 250 ml flask; the flasks were kept in an orbital shaker which was maintained at 120 rpm speed, 25°C, 12 hours photoperiod. The growth period for any strain was kept fixed at 7 days. It was found that marine Naanochloris sp. didn't require the addition of iron; the available iron in the seawater is sufficient to produce 0.5 g/L biomass density. The other two strains had also smaller iron requirement compared to f/2 media. For the three freshwater microalgae, there was also minor requirement for iron (1 mg/L) which was much lesser than iron concentration in BG-11 media. Iron deficiency, during the cultivation process, resulted in bleaching and changes in metabolites (especially in pigments). Nannochloris sp. and Scenedesmous sp. will be later grown in outdoor small raceway tanks (1000 liter) to verify the indoor small scale results.qscienc

Isolation, cultivation, and characterization of novel local marine micro-algae for aquaculture feed supplement production

Aquaculture is considered as a promising alternative to support the food demands of the ever-increasing population. Currently, this sector faces several challenges such as using fishmeal, which is unsustainable and expensive. Therefore, it is necessary to identify an alternative feed component that is sustainable, cost-effective and can provide the essential nutrients required by the fish. In this context, microalgae are considered as a viable source of proteins, lipids, polysaccharides and high-value products (HVPs) such as essential fatty acids, amino acids and vitamins. They play a vital role in the marine food chain and hence can be easily assimilated by the fish. The current research targeted the isolation, identification and characterization of novel marine microalgae from Qatar coastline to produce aquaculture feed supplement. As the climate poses a number of stress factors, such as high light intensities, temperatures and varying salinities, it is expected that novel microalgae with interesting metabolite profiles can be isolated from the environment for developing aquaculture sector in Qatar. Standard plating methods were used to isolate halophilic strains from field waters. PCR-sequencing was used to identify the novel microalgae, cyanobacteria and Diatom isolates. Then a comparative analysis of the growth performance and metabolite content was performed to characterize these strains. Results evidenced that the cyanobacteria strain exhibited the highest biomass productivity of 51.4 mg L-1day-1 whereas the highest lipid content was observed in the novel diatom isolate ranging up to 28.62% and the highest amount of carotenoids was detected in the case of the microalgae. As in conclusion, a rich feed supplement blending the three isolates can be considered as an alternative to fishmeal. As a continuation of this research, the potential strains will be cultivated under various stress to increase their nutritional value

Investigation of the solar culture of microalgae in extreme desert conditions

Cette thèse se place dans le contexte de la production solaire de microalgues dans les conditions désertiques du Qatar. Dans de tels environnements, les microalgues représentent une alternative durable qui peut supporter efficacement les enjeux de la sécurité alimentaire, notamment en raison du manque de terres arables et d’eau douce pour l’agriculture conventionnelle. Cet environnement est également proche de l’idéal d’ensoleillement pour la culture des algues. Cependant, cela se combine à une température moyenne élevée, qui pourrait avoir un effet négatif sur le taux de croissance des algues et la production des métabolites d’intérêt. Un lien étroit existe alors entre les conditions appliquées (qui seront dynamiques), la souche retenue (les effets étant souvent souche-­dépendant), et la technologie de culture utilisée. Cette thèse vise à aborder ces trois aspects. Pour cela, nous nous sommes intéressés à sélectionner des souches adaptées à la production à grande échelle. Cinq souches isolées dans un environnement désertique ont été comparées. Ensuite, la souche la plus prometteuse a été étudiée en détails sous différents régimes de lumière et température. Des expérimentations en photobioréacteurs contrôlés ont permis d’étudier les effets indépendamment, puis en couplage. Les effets propres à des cycles dynamiques tels que rencontrés en extérieurs ont aussi été mis en évidence. La dernière partie présente un modèle thermique d'un système raceway, adapté à la culture au Qatar. Après validation, le modèle a été utilisé pour prédire les échanges et régimes thermiques rencontrés. L'intérêt d'introduire des solutions adaptées de régulation thermique a aussi été étudié.This thesis is placed in the context of the solar culture of microalgae in the desert conditions of Qatar. In such environments, microalgae provide an alternative sustainable solution for food security, especially with the lack of sufficient arable land and fresh water for conventional agriculture. This environment is also close to the ideal regarding available solar radiation. However, this is combined with a high temperature, which could have a negative effect on both growth rate and production of metabolites of interest. A close link then exists between the culture conditions (which will be dynamic), the strain (the effects being often strain-­dependent), and the culture technology used. This thesis aims to address these three aspects. For this, we firstly selected strains adapted to large-­scale production in Qatar. Five strains isolated from the desert environment were compared. Then, the most promising strain was studied under different light and temperature regimes. Experiments in controlled photobioreactors allowed studying the effects independently, and then their inter-­relation. The effects of dynamic cycles as encountered outdoor were also highlighted. The last part presents a thermal model of a raceway system. After validation, the model was used to predict the exchanges and thermal regimes encountered. The interest of introducing adapted thermal regulation solutions has also been studied. The use of heat exchangers using the thermal inertia of the soil has been highlighted, illustrating the interest of combining strain selection to identify robust strain with engineering approaches to develop adapted culture system for Qatar conditions

التكنولوجيا والتقنيات والأمن الغذائي

CENG held a seminar on “Food Security, Technology and Techniques” on November 9, in collaboration with the Ministry of Municipality and Environment (MME). The event aimed to discuss the main techniques that should be followed to enhance food security through investing in technology

Delineating the plastic waste status in the State of Qatar: Potential opportunities, recovery and recycling routes.

The Qatar's national vision (QNV2030) underlines an unequivocal commitment to maintaining harmony between the three inter-dependent pillars of sustainable development: economic growth, social development and environmental management. Nonetheless, it seems that the country is set on a trajectory of unparalleled and rapid development that most waste management and environmental experts would, possibly, characterise as unsustainable; in addition it seems to repeat many of the "errors" that have been made in other parts of the world, including, for example, a lack of developed recycling and waste management infrastructure. The average Municipal Solid Waste (MSW) generation rate per capita in the Gulf Co-operation countries (GCC) reaches almost 1.5 kg/person/d, with the State of Qatar being close to 1.4 kg/person/d during the past years, thereby ranking the Gulf States as some of the highest waste generating countries globally. Plastics, accounting for approx. 13-14% of the total MSW (in these countries), present both a significant amount as well as a valuable resource to be recovered. In the present work, the authors attempt to delineate the plastic recovery status, based on the current waste management and recycling infrastructure existing and operating in Qatar, outlying the drawbacks, but at the same time highlighting the potential opportunities and benefits in developing the waste management and recovery sector in the country

Evidence of the drying technique’s impact on the biomass quality of Tetraselmis subcordiformis (Chlorophyceae)

Abstract Rapid drying, cost-effective and safe, will increase the viability of using microalgae for several bio-industrial applications. In this study, five different drying techniques of microalgal biomass were investigated. These include freeze drying, oven drying, air drying, sun drying, and microwave drying. Morphology, metabolite content, FAME profiling, chlorophyll content, total organic carbon, and total nitrogen were analyzed. Results showed that the freeze-drying technique preserves the highest amounts of chlorophyll, proteins, and lipids. Oven drying underperformed as it retained the lowest amount of chlorophyll, protein, and lipid content. More importantly, FAME profiling results showed that air drying was the best technique in maintaining the highest amount of polyunsaturated fatty acids and more specifically docosahexaenoic acid (DHA). Furthermore, this process requires the least capital and energy needs. The findings from this study confirmed that the drying technique affects the microalga biomass quality. Graphical Abstrac

Study the Potential Use of Waste Water Grown Microalgae Biomass as Biofertilizer

Liquid wastewater streams that contain nitrogen must be treated before being discharged into the environment to prevent eutrophication. Already there are several existing conventional treatment technologies that can remove the nitrogen from the wastewater in combination of multiple processes. Depending on the processes involved, a fraction of nitrogen will be released to the atmosphere. On the contrary, there are several types of microalgae have the voracious demand of nitrogen and can assimilate waste bound nitrogen in a single step mostly as intrinsic proteins. Once the microalgae are separated from the water the minerals inside the microalgae cells remain available for plants and it can be used as fertilizer for the plants. Furthermore, removal of microalgal biomass from the wastewater at the end of the process may completely, or at least partially, treat the waste water minimizing the processes and cost of conventional treatment processes. Qatar's climate and non-arable land are ideal combinations for cultivating microalgae. The harvested microalgae can be dried and stored for future growth of fodder plants. On theory, every kg of microalgae biomass will require 1.73 kg of CO2. Some of the microalgae can also utilize specific organic carbon sources that are available in wastewater. However, the concentration of available organic carbon in the wastewater is not sufficient to support complete removal of nitrogen by microalgae. Hence, carbon dioxide must be supplied for complete and faster treatment. As the minerals will be utilized by the fodder plants, a fraction of the organic carbon associated with the microalgae biomass will be locked in the soil and thus increasing the soil's organic content. Therefore, successful application of wastewater grown microalgae biomass as biofertilizer can provide (1) a cost and energy effective wastewater treatment process, (2) nutrients (N, P and other minerals) recycling, (3) sustainable and environmental friendly agricultural application, and (4) carbon sequestration. Algal technology group of Qatar University is growing microalgae biomass in large scale open ponds. Mineral composition of a marine microalgae, Chlorocystis sp., biomass was characterized as 3.45? N, 0.22? P, 2.78? Ca, 0.39? Fe, 0.01? Cu and 0.02? Zn. Currently, this biomass is used to study its application as biofertilizer for the growth of sorghum plants. Soil was mixed with microalgae biomass and 5 kg of the soil mix was added in each pot. Three different microalgal biomass concentrations were applied in peat soil: 1.5 g/l, 3 g/l and 4.5 g/l. In another pot 3 g/kg NPK fertilizer was added while in another pot there was no inclusion of any fertilizer. Currently, each pot is irrigated with freshwater twice a week and the experiment will continue for two months. In parallel, Scenedesmous sp., a local fast growing freshwater microalgae, is currently being grown in wastewater collected from a small wastewater treatment plant, with an aim to be used as biofertilizer. The mineral composition of wastewater-grown Scenedesmous sp. will be determined and used as appropriate ratio for growing sorghum plants. Results obtained for different fertilizers (i.e., 1. NPK, 2. marine microalgae biomass, and 3. Wastewater grown microalgae biomass) will be compared in terms of plant growth, residual minerals in the soil.qscienc

Data for: Production of phycocyanin by Leptolyngbya sp. in desert environments

Experimental data for light and temperature experiments for biomass and phycocyanin production under turbidostat cultivation conditions for Leptolyngbya sp. QUCCCM 56 Statistical Analysis data files for phycocyanin extraction from A. platensis and Leptolyngbya sp. QUCCCM 5

A study to investigate the energy recovery potential from different macromolecules of a low-lipid marine Tetraselmis sp. biomass through HTL process

This study investigated the hydrothermal liquefaction (HTL) of extracted major macromolecules from Tetraselmis sp. biomass. The carbohydrate fraction was first recovered from Tetraselmis biomass using pressurized heated water. The crude lipid fraction was then extracted from carbohydrate-free biomass by hexane. The remaining biomass was considered as protein extract. HTL runs were conducted from 275 to 350 °C and 30 min for each extract; the maximum biocrude yields for carbohydrate, lipid, and proteins were obtained at 325, 325, and 350 °C, respectively. Next, HTL runs of these macromolecules were conducted at 350 °C for 10–60 min. The highest biocrude yields from carbohydrate, lipid, and protein extracts were obtained at 45, 20, and 45 min, respectively. The optimal energy recovery, as biocrude, from carbohydrate, lipid, and protein extracts were 41, 85, and 81%, respectively. Therefore, microalgae biomass with low carbohydrate content or carbohydrate-extracted biomass could be used as feedstock for biocrude production.The authors would like to acknowledge the support of the Qatar National Research Fund (QNRF, a member of Qatar Foundation) for providing the funding (under grant NPRP8-646-2-272) for this study. The authors also appreciate the assistance of Dr. Ahmed from the Central Laboratories Unit (CLU), Qatar University, for the CHNS analysis

Microalgae biomass production in municipal wastewater and use of the produced biomass as sustainable biofertilizer

Due to the lack of natural water sources, and cost and environmental issues associated with water desalination, Qatar currently emphasizes on the reuse of current wastewater sources, which includes conventional and unconventional approaches to utilize every available water sources, and ultimately promoting the wastewater stream driving from local municipalities. Currently, very few approaches have been taken to utilize this municipal wastewater sources. Moreover, municipal wastewater can also be utilized as growth media for producing microalgae biomass. A well-known approached is to utilize wastewater stream in an integrated farming system such as open pond microalgae cultivation system. In general microalgae, cultivation system requires a large quantity of water supply where additional nutrients and carbon dioxide are needed for microalgae biomass production. Whereas, microalgae grown in municipal wastewater can utilize the available N, P and other trace metals and therefore additional nutrients are not required. The process starts with the integrated treatment of municipal wastewater by selective local microalgae strains which can tolerate the complex stress deriving from the wastewater, consequently producing valuable by-products with zero wastes. In addition, during the cultivation, flue gas can be injected to enhance the biomass productivity. The aims of this study were to screen and optimize native microalgae strains growth in the wastewater stream from Al-Khor municipality. After screening microalgae strains with closed controlled condition, they were tested further with the ambient outdoor conditions in High Rate Algal Pond 200 L open system, using same municipal wastewater. Microalgae biomass were harvested after 10 days of experiments to utilize them as a biofertilizer. Among the microalgae strains two microalgae strain Chlorella sp. and Scenedesmus sp. shown higher biomass yield after the growth period. Overall Chlorella sp. gives a higher nitrogen and phosphorus uptake from the municipal wastewater effluent. Further study also showed a higher plant growth when municipal wastewater grown microalgae biomass was used as biofertilizer as compared to conventional inorganic fertilizer.qscienc