One of the major nutritional requirements in our diet is an adequate intake of omega-3 specially eicosapentaenoic acid (EPA). In the present study, the effects of two temperatures (16°C & 20˚C) and light intensities (140 & 180µE/M2.S) and four nitrate levels (0.075, 0.3, 0.5 and 0.7g/L) on the cell growth and lipid productivity of Porphyridium cruentum, one of the most promising oil-rich species of microalgae, were investigated. A growth comparison was carried out using pure CO2 and 5% CO2/air. Additionally, the ratio of the fatty acids with omega-3 and omega-6 groups at various growth conditions were compared, since an appropriate proportion of omega-6 (arachidonic acid(ARA)) to omega-3(EPA) is vital for healthy nutrition. Lower EPA production and consequently higher ARA/EPA ratio occurred when 5%CO2/Air was utilized as CO2 supplementation. The highest biomass productivity (143 mg/L.day) and EPA (13.08%w/w) were achieved at 20˚C, 140µE/M2.S and 0.3g/L nitrate, while lipid content was the lowest (0.5%w/w) at this condition. The optimal growth condition to produce the lowest ARA/EPA, 2.17, was achieved at 20°C, 140µE/M2.S (pure CO2) and 0.5g/L nitrate.
The possible growth of P. cruentum in ultra-filtered swine wastewater was also evaluated in this study. P. cruentum was grown in different waste dilutions (total nitrogen concentrations of 12.4, 49.4, 82.4 and 115.3mg/L) to achieve the optimum nutrient condition for producing EPA. Various salinities (0-3.2%) were examined in the optimum nitrogen concentration. The data were compared to L1-medium and the results generally demonstrate better growth of P. cruentum in swine waste with higher lipid productivity and lipid content. The maximum lipid productivity (143mg/L) and lipid content (4.71 mg/100g biomass) was achieved in 3.2% salinity swine waste with 82.4mg/L nitrogen concentration while control medium with 2.5% salinity resulted the highest biomass productivity (3.76g/L). Markedly higher biomass productivity, lipid productivity and lipid content were achieved from swine waste culture diluted with seawater compared to saltwater. Higher C16:0, 18:2 and C20:5 (EPA) and lower C18:0 and ARA/EPA were achieved from swine waste culture compared to the control medium. Generally, the minimum ARA/EPA(1.33) was obtained at 82.4mg/L nitrogen concentration and 3.2% salinity in swine waste diluted with seawater.
","abstract_html":"<p>One of the major nutritional requirements in our diet is an adequate intake of omega-3 specially eicosapentaenoic acid (EPA). In the present study, the effects of two temperatures (16°C & 20˚C) and light intensities (140 & 180µE/M2.S) and four nitrate levels (0.075, 0.3, 0.5 and 0.7g/L) on the cell growth and lipid productivity of Porphyridium cruentum, one of the most promising oil-rich species of microalgae, were investigated. A growth comparison was carried out using pure CO2 and 5% CO2/air. Additionally, the ratio of the fatty acids with omega-3 and omega-6 groups at various growth conditions were compared, since an appropriate proportion of omega-6 (arachidonic acid(ARA)) to omega-3(EPA) is vital for healthy nutrition. Lower EPA production and consequently higher ARA/EPA ratio occurred when 5%CO2/Air was utilized as CO2 supplementation. The highest biomass productivity (143 mg/L.day) and EPA (13.08%w/w) were achieved at 20˚C, 140µE/M2.S and 0.3g/L nitrate, while lipid content was the lowest (0.5%w/w) at this condition. The optimal growth condition to produce the lowest ARA/EPA, 2.17, was achieved at 20°C, 140µE/M2.S (pure CO2) and 0.5g/L nitrate.</p> <p>The possible growth of P. cruentum in ultra-filtered swine wastewater was also evaluated in this study. P. cruentum was grown in different waste dilutions (total nitrogen concentrations of 12.4, 49.4, 82.4 and 115.3mg/L) to achieve the optimum nutrient condition for producing EPA. Various salinities (0-3.2%) were examined in the optimum nitrogen concentration. The data were compared to L1-medium and the results generally demonstrate better growth of P. cruentum in swine waste with higher lipid productivity and lipid content. The maximum lipid productivity (143mg/L) and lipid content (4.71 mg/100g biomass) was achieved in 3.2% salinity swine waste with 82.4mg/L nitrogen concentration while control medium with 2.5% salinity resulted the highest biomass productivity (3.76g/L). Markedly higher biomass productivity, lipid productivity and lipid content were achieved from swine waste culture diluted with seawater compared to saltwater. Higher C16:0, 18:2 and C20:5 (EPA) and lower C18:0 and ARA/EPA were achieved from swine waste culture compared to the control medium. Generally, the minimum ARA/EPA(1.33) was obtained at 82.4mg/L nitrogen concentration and 3.2% salinity in swine waste diluted with seawater.</p>","abstract_has_math":false,"creators":["Asgharpour, Maryam"],"institution":null,"degree_name":"Doctor of Philosophy in Engineering (PhD)","degree_level":"Dissertation","degree_discipline":null,"degree_department":null,"school":null,"contributors":["Beitle, Robert R. Jr.","Hestekin, Christa N."],"advisors":["Hestekin, Jamie A."],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-12-01T08:00:00Z","date_published":"2015-12-01T08:00:00Z","updated_at":"2026-07-24T00:58:44Z","subjects":["Biological sciences","Applied sciences","Health and environmental sciences","Eicosapentaenoic acid","Fatty acids","Microalgae","Photo bioreactor","Porphyridium cruentum","Swine waste water","Cell Biology","Other Chemical Engineering","Pharmacology"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholarworks.uark.edu/etd/1438","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Beitle, Robert R. Jr.","Hestekin, Christa N."]},{"key":"dc:contributor.advisor","label":"Advisor","values":["Hestekin, Jamie A."]},{"key":"dc:creator","label":"Author","values":["Asgharpour, Maryam"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2017-09-29T07:00:00Z"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy in Engineering (PhD)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Biological sciences","Applied sciences","Health and environmental sciences","Eicosapentaenoic acid","Fatty acids","Microalgae","Photo bioreactor","Porphyridium cruentum","Swine waste water","Cell Biology","Other Chemical Engineering","Pharmacology"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarworks.uark.edu/etd/1438"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["One of the major nutritional requirements in our diet is an adequate intake of omega-3 specially eicosapentaenoic acid (EPA). In the present study, the effects of two temperatures (16°C & 20˚C) and light intensities (140 & 180µE/M2.S) and four nitrate levels (0.075, 0.3, 0.5 and 0.7g/L) on the cell growth and lipid productivity of Porphyridium cruentum, one of the most promising oil-rich species of microalgae, were investigated. A growth comparison was carried out using pure CO2 and 5% CO2/air. Additionally, the ratio of the fatty acids with omega-3 and omega-6 groups at various growth conditions were compared, since an appropriate proportion of omega-6 (arachidonic acid(ARA)) to omega-3(EPA) is vital for healthy nutrition. Lower EPA production and consequently higher ARA/EPA ratio occurred when 5%CO2/Air was utilized as CO2 supplementation. The highest biomass productivity (143 mg/L.day) and EPA (13.08%w/w) were achieved at 20˚C, 140µE/M2.S and 0.3g/L nitrate, while lipid content was the lowest (0.5%w/w) at this condition. The optimal growth condition to produce the lowest ARA/EPA, 2.17, was achieved at 20°C, 140µE/M2.S (pure CO2) and 0.5g/L nitrate.
The possible growth of P. cruentum in ultra-filtered swine wastewater was also evaluated in this study. P. cruentum was grown in different waste dilutions (total nitrogen concentrations of 12.4, 49.4, 82.4 and 115.3mg/L) to achieve the optimum nutrient condition for producing EPA. Various salinities (0-3.2%) were examined in the optimum nitrogen concentration. The data were compared to L1-medium and the results generally demonstrate better growth of P. cruentum in swine waste with higher lipid productivity and lipid content. The maximum lipid productivity (143mg/L) and lipid content (4.71 mg/100g biomass) was achieved in 3.2% salinity swine waste with 82.4mg/L nitrogen concentration while control medium with 2.5% salinity resulted the highest biomass productivity (3.76g/L). Markedly higher biomass productivity, lipid productivity and lipid content were achieved from swine waste culture diluted with seawater compared to saltwater. Higher C16:0, 18:2 and C20:5 (EPA) and lower C18:0 and ARA/EPA were achieved from swine waste culture compared to the control medium. Generally, the minimum ARA/EPA(1.33) was obtained at 82.4mg/L nitrogen concentration and 3.2% salinity in swine waste diluted with seawater.
"]},{"key":"dc:title","label":"Title","values":["Eicosapentaenoic Acid (EPA) from Porphyridium Cruentum: Increasing Growth and Productivity of the Microalgae for Pharmaceutical Products"]}]}],"canonical_facts":{"dc:contributor":["Beitle, Robert R. Jr.","Hestekin, Christa N."],"dc:contributor.advisor":["Hestekin, Jamie A."],"dc:creator":["Asgharpour, Maryam"],"dc:date":["2015"],"dc:date.available":["2017-09-29T07:00:00Z"],"dc:description.abstract":["One of the major nutritional requirements in our diet is an adequate intake of omega-3 specially eicosapentaenoic acid (EPA). In the present study, the effects of two temperatures (16°C & 20˚C) and light intensities (140 & 180µE/M2.S) and four nitrate levels (0.075, 0.3, 0.5 and 0.7g/L) on the cell growth and lipid productivity of Porphyridium cruentum, one of the most promising oil-rich species of microalgae, were investigated. A growth comparison was carried out using pure CO2 and 5% CO2/air. Additionally, the ratio of the fatty acids with omega-3 and omega-6 groups at various growth conditions were compared, since an appropriate proportion of omega-6 (arachidonic acid(ARA)) to omega-3(EPA) is vital for healthy nutrition. Lower EPA production and consequently higher ARA/EPA ratio occurred when 5%CO2/Air was utilized as CO2 supplementation. The highest biomass productivity (143 mg/L.day) and EPA (13.08%w/w) were achieved at 20˚C, 140µE/M2.S and 0.3g/L nitrate, while lipid content was the lowest (0.5%w/w) at this condition. The optimal growth condition to produce the lowest ARA/EPA, 2.17, was achieved at 20°C, 140µE/M2.S (pure CO2) and 0.5g/L nitrate.
The possible growth of P. cruentum in ultra-filtered swine wastewater was also evaluated in this study. P. cruentum was grown in different waste dilutions (total nitrogen concentrations of 12.4, 49.4, 82.4 and 115.3mg/L) to achieve the optimum nutrient condition for producing EPA. Various salinities (0-3.2%) were examined in the optimum nitrogen concentration. The data were compared to L1-medium and the results generally demonstrate better growth of P. cruentum in swine waste with higher lipid productivity and lipid content. The maximum lipid productivity (143mg/L) and lipid content (4.71 mg/100g biomass) was achieved in 3.2% salinity swine waste with 82.4mg/L nitrogen concentration while control medium with 2.5% salinity resulted the highest biomass productivity (3.76g/L). Markedly higher biomass productivity, lipid productivity and lipid content were achieved from swine waste culture diluted with seawater compared to saltwater. Higher C16:0, 18:2 and C20:5 (EPA) and lower C18:0 and ARA/EPA were achieved from swine waste culture compared to the control medium. Generally, the minimum ARA/EPA(1.33) was obtained at 82.4mg/L nitrogen concentration and 3.2% salinity in swine waste diluted with seawater.
"],"dc:identifier":["https://scholarworks.uark.edu/etd/1438"],"dc:subject":["Biological sciences","Applied sciences","Health and environmental sciences","Eicosapentaenoic acid","Fatty acids","Microalgae","Photo bioreactor","Porphyridium cruentum","Swine waste water","Cell Biology","Other Chemical Engineering","Pharmacology"],"dc:title":["Eicosapentaenoic Acid (EPA) from Porphyridium Cruentum: Increasing Growth and Productivity of the Microalgae for Pharmaceutical Products"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Doctor of Philosophy in Engineering (PhD)"]},"updated_at":"2026-07-24T00:58:44Z"}