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Aiming at the reutilizing wastewater for algal growth and biomass production, a saline water rejected from reverse osmosis (RO) facility (salinity 67.59 g L−1) was used to cultivate the pre-adapted green microalga Chlorella vulgaris. The inoculum was prepared by growing cells in modified BG-11 medium, and adaptation was performed by applying a gradual increase in salinity (56.0 g L−1 NaCl and 125 ppm FeSO4·7H2O) to the culture in 200 L photobioreactor. Experiments using the adapted alga were performed using original-rejected water (ORW) and treated rejected water (TRW) comparing with the recommended growth medium (BG-11). The initial salinity of ORW was chemically reduced to 39.1 g L−1 to obtain TRW. Vertical photobioreactors (15 L) was used for indoor growth experiments. Growth in BG-11 resulted in 1.23 g L−1, while the next adaptation growth reached 2.14 g L−1 of dry biomass. The dry weights of re-cultivated Chlorella after adaptation were 1.49 and 2.19 g L−1 from ORW and TRW; respectively. The cellular oil content was only 12% when cells grown under control conditions verses to 14.3 and 15.42% with original and treated water, respectively. Induction of stress affected the fatty acid methyl esters (FAMEs) profile and the properties of the resulting biodiesel. The present results indicated that induction of stress by high salinity improves the quality of FAMEs that can be used as a promising biodiesel fuel.
Adel W. Almutairi; Abo El-Khair B. El-Sayed; Marwa M. Reda. Evaluation of high salinity adaptation for lipid bio-accumulation in the green microalga Chlorella vulgaris. Saudi Journal of Biological Sciences 2021, 28, 3981 -3988.
AMA StyleAdel W. Almutairi, Abo El-Khair B. El-Sayed, Marwa M. Reda. Evaluation of high salinity adaptation for lipid bio-accumulation in the green microalga Chlorella vulgaris. Saudi Journal of Biological Sciences. 2021; 28 (7):3981-3988.
Chicago/Turabian StyleAdel W. Almutairi; Abo El-Khair B. El-Sayed; Marwa M. Reda. 2021. "Evaluation of high salinity adaptation for lipid bio-accumulation in the green microalga Chlorella vulgaris." Saudi Journal of Biological Sciences 28, no. 7: 3981-3988.
Economic viability of biodiesel production relies mainly on the productivity of biomass and microalgal lipids. In addition, production of omega fatty acids is favorable for human nutrition. Thus, enhancement of lipid accumulation with high proportion of omega fatty acids could help the dual use of microalgal lipids in human nutrition and biodiesel production through biorefinery. In that context, phytohormones have been identified as a promising factor to increase biomass and lipids production. However, nitrogen limitation has been discussed as a potential tool for lipid accumulation in microalgae, which results in simultaneous growth retardation. The present study aims to investigate the combined effect of N-depletion and 3-Indoleacetic acid (IAA) supplementation on lipid accumulation of the marine eustigmatophyte Nannochloropsis oceanica as one of the promising microalgae for omega fatty acids production. The study confirmed that N-starvation stimulates the lipid content of N. oceanica. IAA enhanced both growth and lipid accumulation due to enhancement of pigments biosynthesis. Therefore, combination effect of IAA and nitrogen depletion showed gradual increase in the dry weight compared to the control. Lipid analysis showed lower quantity of saturated fatty acids (SFA, 26.25%) than the sum of monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA). Under N-depletion, SFA decreased by 12.98% compared to the control, which recorded much reduction by increasing of IAA concentration. Reduction of SFA was in favor of PUFA, mainly omega-6 and omega-3 fatty acids which increased significantly due to IAA combined with N-depletion. Thus, the present study suggests a biorefinery approach for lipids extracted from N. oceanica for dual application in nutrition followed by biodiesel production.
Hussein Touliabah; Adel Almutairi. Effect of Phytohormones Supplementation under Nitrogen Depletion on Biomass and Lipid Production of Nannochloropsis oceanica for Integrated Application in Nutrition and Biodiesel. Sustainability 2021, 13, 592 .
AMA StyleHussein Touliabah, Adel Almutairi. Effect of Phytohormones Supplementation under Nitrogen Depletion on Biomass and Lipid Production of Nannochloropsis oceanica for Integrated Application in Nutrition and Biodiesel. Sustainability. 2021; 13 (2):592.
Chicago/Turabian StyleHussein Touliabah; Adel Almutairi. 2021. "Effect of Phytohormones Supplementation under Nitrogen Depletion on Biomass and Lipid Production of Nannochloropsis oceanica for Integrated Application in Nutrition and Biodiesel." Sustainability 13, no. 2: 592.
: In the present study, the marine microalga Tisochrysis lutea was cultivated mixotrophically in F2 growth medium with sodium acetate as exogenous carbon source. The medium was composed of different concentrations of nitrogen to determine the impact of nitrogen depletion on cellular growth and chemical composition. Nitrogen depletion led to severely decreased growth and protein content. However, mild nitrogen depletion (0.22 mM NaNO3) led to maximum lipid yield. The fatty acid methyl ester profile also showed increased unsaturation as the nitrogen content decreased. Growth in nitrogen-free medium increased the proportions of mono- and poly-unsaturated fatty acids, while the proportion of saturated fatty acids decreased. Growth under all tested nitrogen levels showed undetectable fatty acids with ≥4 double bonds, indicating these fatty acids had oxidative stability. In addition, all tested nitrogen concentrations led to specific gravity, kinematic viscosity, iodine value, and cetane number that meet the standards for Europe and the U.S.A. However, growth in the presence of nitrogen deficiency enhanced the higher heating value of the resulting biodiesel, a clear advantage from the perspective of energy efficiency. Thus, mixotrophic cultivation of T. lutea with nitrogen limitation provides a promising approach to achieve high lipid productivity and production of high-quality biodiesel.
Adel W. Almutairi. Improvement of Chemical Composition of Tisochrysis lutea Grown Mixotrophically under Nitrogen Depletion towards Biodiesel Production. Molecules 2020, 25, 4609 .
AMA StyleAdel W. Almutairi. Improvement of Chemical Composition of Tisochrysis lutea Grown Mixotrophically under Nitrogen Depletion towards Biodiesel Production. Molecules. 2020; 25 (20):4609.
Chicago/Turabian StyleAdel W. Almutairi. 2020. "Improvement of Chemical Composition of Tisochrysis lutea Grown Mixotrophically under Nitrogen Depletion towards Biodiesel Production." Molecules 25, no. 20: 4609.
The aim of this work was to evaluate a novel integrated biorefinery route for enhanced energy recovery from seaweeds and microalgae. Agar extraction prior to anaerobic digestion recorded the highest biogas productivity of 32.57 L kg−1 VS d−1. Supplementation of the microalgal growth medium with anaerobic digestate from agar-extracted biomass enhanced the microalgal growth, recording the highest dry weight of 4.57 g L−1 at 20% digestate ratio. In addition, lipid content showed the highest value of 25.8 %dw. Due to enhancement of growth and lipid content, 20% digestate ratio showed the highest lipid productivity and FAMEs recovery (65.2 mg L−1 d−1 and 123.3 mg g−1dw, respectively), with enhanced biodiesel characteristics. The present study estimated annual revenue of 1252.7 US$ ton−1 from the whole Gracilaria multipartita biomass conversion into biogas, while that through agar extraction deserved 36087.0 US$ ton−1, with enhanced annual biodiesel yield by 69.7% over the control medium.
Abd El-Fatah Abomohra; Adel Almutairi. A close-loop integrated approach for microalgae cultivation and efficient utilization of agar-free seaweed residues for enhanced biofuel recovery. Bioresource Technology 2020, 317, 124027 .
AMA StyleAbd El-Fatah Abomohra, Adel Almutairi. A close-loop integrated approach for microalgae cultivation and efficient utilization of agar-free seaweed residues for enhanced biofuel recovery. Bioresource Technology. 2020; 317 ():124027.
Chicago/Turabian StyleAbd El-Fatah Abomohra; Adel Almutairi. 2020. "A close-loop integrated approach for microalgae cultivation and efficient utilization of agar-free seaweed residues for enhanced biofuel recovery." Bioresource Technology 317, no. : 124027.
The haptophyte microalga Tisochrysis lutea was heterotrophically grown in F2 medium with different combinations of pH and salinity. Growth, oil content and fatty acids (FAs) profile were determined under each set of conditions. The salinity was adjusted using NaCl at concentrations of 0.4, 0.6, 0.8, or 1.0 M, while pH was adjusted at 7, 8, or 9, and heterotrophic growth was performed using organic carbon in the form of sugar cane industry waste (CM). Fatty acid methyl esters (FAMEs) were identified by gas chromatography. The results showed that pH of 8.0 was the optimal for dry weight and oil production, regardless of the salinity level. At pH 8.0, growth at a salinity of 0.4 M NaCl was optimal for biomass accumulation (1.185 g L-1). Under these conditions, the maximum growth rate was 0.055 g L-1 d-1, with a doubling time of 17.5 h and a degree of multiplication of 2.198. Oil content was maximal (34.87%) when the salinity was 0.4 M and the pH was 9.0. The ratio of saturated to unsaturated FAs was affected by the pH value and salinity, in that unsaturated FAs increased to 58.09% of the total FAs, considerably greater than the value of 40.59% obtained for the control (0.4 M NaCl and pH 8.0).
Adel W. Almutairi; Abo El-Khair B. El-Sayed; Marwa M. Reda. Combined effect of salinity and pH on lipid content and fatty acid composition of Tisochrysis lutea. Saudi Journal of Biological Sciences 2020, 27, 3553 -3558.
AMA StyleAdel W. Almutairi, Abo El-Khair B. El-Sayed, Marwa M. Reda. Combined effect of salinity and pH on lipid content and fatty acid composition of Tisochrysis lutea. Saudi Journal of Biological Sciences. 2020; 27 (12):3553-3558.
Chicago/Turabian StyleAdel W. Almutairi; Abo El-Khair B. El-Sayed; Marwa M. Reda. 2020. "Combined effect of salinity and pH on lipid content and fatty acid composition of Tisochrysis lutea." Saudi Journal of Biological Sciences 27, no. 12: 3553-3558.
Marwa Reda; Abo El-Khair El-Sayed; Adel Almutairi; Hassoub A. Fatty Acid Profiles and Fuel Properties of Oils from Castor Oil Plants Irrigated by Microalga-treated Wastewater. Egyptian Journal of Botany 2020, 1 .
AMA StyleMarwa Reda, Abo El-Khair El-Sayed, Adel Almutairi, Hassoub A. Fatty Acid Profiles and Fuel Properties of Oils from Castor Oil Plants Irrigated by Microalga-treated Wastewater. Egyptian Journal of Botany. 2020; ():1.
Chicago/Turabian StyleMarwa Reda; Abo El-Khair El-Sayed; Adel Almutairi; Hassoub A. 2020. "Fatty Acid Profiles and Fuel Properties of Oils from Castor Oil Plants Irrigated by Microalga-treated Wastewater." Egyptian Journal of Botany , no. : 1.
Effects of 12 heavy metals on growth of free and alginate-immobilized cells of the alga Pseudokirchneriella subcapitata were investigated. The tested metals ions include Al, As, Cd, Co, Cr, Cu, Hg, Se, Ni, Pb, Sr, and Zn. Toxicity values (EC50) were calculated by graphical interpolation from dose-response curves. The highest to the lowest toxic metals are in the order Cd > Co > Hg > Cu > Ni > Zn > Cr > Al > Se > As > Pb > Sr. The lowest metal concentration (mg L−1) inhibiting 50% (EC50) of algal growth of free and immobilized (values in parentheses) algal cells were, 0.018 (0.09) for Cd, 0.03 (0.06) for Co, 0.039 (0.06) for Hg, 0.048 (0.050) for Cu, 0.055 (0.3) for Ni, 0.08 (0.1) for Zn, 0.2 (0.3) for Cr, 0.75 (1.8) for Al, 1.2 (1.4) for Se, 3.0 (4.0) for As, 3.3 (5.0) for Pb, and 160 (180) for Sr. Free and immobilized cultures showed similar responses to Cu and Se. The free cells were more sensitive than the immobilized ones. Accordingly, the toxicity (EC50) of heavy metals derived only form immobilized algal cells might by questionable. The study suggests that batteries of alginate-immobilized algae can efficiently replace free algae for the bio-removal of heavy metals.
Zaki M. Al-Hasawi; Mohammad I. Abdel-Hamid; Adel W. Almutairi; Hussein E. Touliabah. Response of Pseudokirchneriella subcapitata in Free and Alginate Immobilized Cells to Heavy Metals Toxicity. Molecules 2020, 25, 2847 .
AMA StyleZaki M. Al-Hasawi, Mohammad I. Abdel-Hamid, Adel W. Almutairi, Hussein E. Touliabah. Response of Pseudokirchneriella subcapitata in Free and Alginate Immobilized Cells to Heavy Metals Toxicity. Molecules. 2020; 25 (12):2847.
Chicago/Turabian StyleZaki M. Al-Hasawi; Mohammad I. Abdel-Hamid; Adel W. Almutairi; Hussein E. Touliabah. 2020. "Response of Pseudokirchneriella subcapitata in Free and Alginate Immobilized Cells to Heavy Metals Toxicity." Molecules 25, no. 12: 2847.
Pennate diatom Nitzschia palea can be cultured in outdoor vertical-bed photobioreactors to produce biodiesel. To assess the production of biomass and lipids, non-axenic cultures of Nitzschia palea were grown outdoors, and the growth of these cultures was measured biweekly. During the annual cycle of algal culture, the culture temperature ranged from 17.3 °C to 33.5 °C, the dry weight biomass ranged from 0.11 g l−1 to 0.25 g l−1, light energy] ranged from 1.94 Wm−2 to 3.9 Wm−2 and intracellular lipid content ranged from 7.1% to 11.4% of biomass weight after drying at 60 °C. Gas chromatography/mass spectroscopy (GC/MS) analysis of n-hexane extracts showed that the intracellular lipids were primarily C14:0 myristic acid (9.01%), C15:0 pentadecyclic acid (8.26%) and two types of C16:0, palmitic acid (41.13%) and palmitoleic acid (29.25%). Gel permeation analysis showed that carboxylic acids comprised 28.9% of lipids, 16.3% of monoglycerides, 27.3% of diglycerides and 24.3% of triglycerides. Alcoholysis of lipids resulted in the conversion of about 93.9% of fatty acids to equivalent fatty acid methyl esters (FAME) or biodiesel, which, on basis of wt%, consisted primarily of C15:0 methyl myristate (8.3%), C16:0 methyl pentadecanoate] (7.2%), C17:1methyl palmitoleate (28.7%) and methyl palimtate](39.8%).
Hussein E. Touliabah; M.I. Abdel-Hamid; Adel Almutairi. Long-term monitoring of the biomass and production of lipids by Nitzschia palea for biodiesel production. Saudi Journal of Biological Sciences 2020, 27, 2038 -2046.
AMA StyleHussein E. Touliabah, M.I. Abdel-Hamid, Adel Almutairi. Long-term monitoring of the biomass and production of lipids by Nitzschia palea for biodiesel production. Saudi Journal of Biological Sciences. 2020; 27 (8):2038-2046.
Chicago/Turabian StyleHussein E. Touliabah; M.I. Abdel-Hamid; Adel Almutairi. 2020. "Long-term monitoring of the biomass and production of lipids by Nitzschia palea for biodiesel production." Saudi Journal of Biological Sciences 27, no. 8: 2038-2046.
This study was designed to assess the synergistic effects of nitrogen (N) and phosphorus (P) concentrations on oil content, fatty acid profile, and predicted fuel properties of Dunaliella salina. Axenic D. salina cells were grown in F/2 growth medium of salinity 34 ppt containing 33.6 g.l−1 ultramarine synthetic sea salt. Growth dry weight, cell count, and their relationship were measured, and oils were extracted by soaking following Soxhlet extraction. Growth dry weight was markedly affected by N and P concentrations, with maximum growth dry weights of cultures grown at recommended N and P concentrations (control), half of the recommended N concentration (0.5 N) and (0.5 N/0.5P) being 0.911 g.l−1, 0.755 g.l−1, and 0.615 g.l−1, respectively. Oil content showed the reverse pattern, with cultures grown in the absence of phosphorus (0.0P), full N/P starvation (0.0 N/0.0P), and control resulting in maximum oil contents of 24.86%, 22.85%, and 5.88%, respectively. The majority of fatty acid methyl esters ranged between C14 and C22. Estimated fuel properties of algal cells grown under NP stress conditions were found to meet the American Society for Testing and Materials (ASTM) and European Committee for Standardization (EN) guidelines.
Adel W. Almutairi. Effects of nitrogen and phosphorus limitations on fatty acid methyl esters and fuel properties of Dunaliella salina. Environmental Science and Pollution Research 2020, 27, 32296 -32303.
AMA StyleAdel W. Almutairi. Effects of nitrogen and phosphorus limitations on fatty acid methyl esters and fuel properties of Dunaliella salina. Environmental Science and Pollution Research. 2020; 27 (26):32296-32303.
Chicago/Turabian StyleAdel W. Almutairi. 2020. "Effects of nitrogen and phosphorus limitations on fatty acid methyl esters and fuel properties of Dunaliella salina." Environmental Science and Pollution Research 27, no. 26: 32296-32303.
Hussein E. Touliabah; Adel Almutairi. Phytoplankton Studies of the Rabigh Dam Stream, Makkah Province, Saudi Arabia. Egyptian Journal of Botany 2019, 1 .
AMA StyleHussein E. Touliabah, Adel Almutairi. Phytoplankton Studies of the Rabigh Dam Stream, Makkah Province, Saudi Arabia. Egyptian Journal of Botany. 2019; ():1.
Chicago/Turabian StyleHussein E. Touliabah; Adel Almutairi. 2019. "Phytoplankton Studies of the Rabigh Dam Stream, Makkah Province, Saudi Arabia." Egyptian Journal of Botany , no. : 1.
Plasmid pBI221aadAGUS which carried both of GUS (β-glucuronidase) and aadA (aminoglyoside transferase) genes besides of the 35S cauliflower mosaic virus promoter was constructed and used for stable nuclear transformation of Chlamydomonas reinhardtii. The vector was transformed into the alga by particle gun bombardment and two positive colonies were selected on spectinomycin–containing medium. The restriction analysis of the DNA of the positive colonies showed that aadA was inserted in two orientations. The presence of introduced genes in the transformed colonies was confirmed by (PCR) using primers specific to GUS and aadA genes. The expression of aadA and GUS genes was revealed in all colonies that were grown on spectinomycin in liquid culture for 3–4 generations. The usefulness of this vector, differing in the orientation of the aadA cassette, was manisfested by transforming C. reinhardtii to spectinomycin resistance in the stable expression. This constructed plasmid-based expression vector system would help to unravel the functions of various genes in the green alga.
Mostafa M. El-Sheekh; Adel W. Almutairi; Hussein E. Touliabah. Construction of a novel vector for the nuclear transformation of the unicellular green alga Chlamydomonas reinhardtii and its stable expression. Journal of Taibah University for Science 2019, 13, 529 -535.
AMA StyleMostafa M. El-Sheekh, Adel W. Almutairi, Hussein E. Touliabah. Construction of a novel vector for the nuclear transformation of the unicellular green alga Chlamydomonas reinhardtii and its stable expression. Journal of Taibah University for Science. 2019; 13 (1):529-535.
Chicago/Turabian StyleMostafa M. El-Sheekh; Adel W. Almutairi; Hussein E. Touliabah. 2019. "Construction of a novel vector for the nuclear transformation of the unicellular green alga Chlamydomonas reinhardtii and its stable expression." Journal of Taibah University for Science 13, no. 1: 529-535.