Growth patterns in Artificial Sea Waters of two newly-isolated Picochlorum oklahomense strains from the coasts of Ionian Sea (Greece)
Panagiotis Dritsas, George Aggelis
Unit of Microbiology, Section of Genetics, Cell and Developmental Biology, Department of Biology, University of Patras, 26504 Patras, Greece
Microalgae constitute a diverse group of photosynthetic microorganisms of high importance for basic research and biotechnological applications. The aim of this study was the investigation of the effect of nitrogen and phosphorus concentration on biomass and nutritionally interesting cellular components (i.e., lipid, protein) production of two newly-isolated Picochlorum oklahomense strains from the Ionian Sea (Greece). All the experiments were performed in an Open Pond Simulating Reactor – OPSR of total volume 8.7 L (working volume, Vw = 5.0 L) under constant illumination 232 μmol m-2 s-1 for approximately 450 h. A modified Artificial Sea Water (mASW) was served as growth medium, in three variations. Specifically, mASW (i.e. control, containing KNO3: 1.0 g L-1 and KH2PO4: 0.07 g L-1); mASW containing KNO3: 0.1 g L-1; and mASW containing KH2PO4: 0.02 g L-1. Both strains gained satisfying amounts of dry biomass (i.e., 299.3 ± 9.6 mg L-1 and 421.1 ± 30.8 mg L-1 for P. oklahomense SAG4.4 and P. oklahomense PAT3.2B, respectively) and accumulated considerable levels of lipids (i.e., 9.4 ± 1.1, % w/w, and 11.5 ± 0.3, % w/w, respectively) when cultivated under control conditions. Nitrogen limitation affectedboth strains in a negative way as they produced less biomass (i.e., 195.7 ± 10.2 mg L1 for P. oklahomense SAG4.4 while P. oklahomense PAT3.2B gained only 98.0 ± 4.6 mg L-1) and lipids (e.g., P. oklahomense PAT3.2B gained up to 5.1 ± 1.0, % w/w).Under phosphorus limitation, the two strains presented differences in terms of biomass production. P. oklahomense SAG4.4 gained almost 1.8 times higher biomass (i.e. 529.0 ± 36.9 mg L-1), while lipid accumulation was slightly lower (i.e. 5.7 ± 1.6, % w/w) comparing to the control experiment. On the other hand, P. oklahomense PAT3.2B marked low biomass levels (i.e. 125.3 ± 4.1 mg L-1 ) but similar levels of intracellular lipids (i.e. 6.0 ± 2.5, % w/w) comparing to its control experiment. Lastly,the microalgal cell mass in all cases contained proteins (ranging 29.1 – 49.2, % w/w) in considerable levels. The biochemical profiles of the two isolates, especially when cultivated in environment rich in nitrogen and phosphorus, highlight them as suitable candidates for use in various industrial applications.
DGF – 4th ISML – Microalgae
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Posted: 20 Φεβρουαρίου, 2024 by dritsas
#1 | 4th International Symposium on Microbial Lipids
Growth patterns in Artificial Sea Waters of two newly-isolated Picochlorum oklahomense strains from the coasts of Ionian Sea (Greece)
Panagiotis Dritsas, George Aggelis
Unit of Microbiology, Section of Genetics, Cell and Developmental Biology, Department of Biology, University of Patras, 26504 Patras, Greece
Microalgae constitute a diverse group of photosynthetic microorganisms of high importance for basic research and biotechnological applications. The aim of this study was the investigation of the effect of nitrogen and phosphorus concentration on biomass and nutritionally interesting cellular components (i.e., lipid, protein) production of two newly-isolated Picochlorum oklahomense strains from the Ionian Sea (Greece). All the experiments were performed in an Open Pond Simulating Reactor – OPSR of total volume 8.7 L (working volume, Vw = 5.0 L) under constant illumination 232 μmol m-2 s-1 for approximately 450 h. A modified Artificial Sea Water (mASW) was served as growth medium, in three variations. Specifically, mASW (i.e. control, containing KNO3: 1.0 g L-1 and KH2PO4: 0.07 g L-1); mASW containing KNO3: 0.1 g L-1; and mASW containing KH2PO4: 0.02 g L-1. Both strains gained satisfying amounts of dry biomass (i.e., 299.3 ± 9.6 mg L-1 and 421.1 ± 30.8 mg L-1 for P. oklahomense SAG4.4 and P. oklahomense PAT3.2B, respectively) and accumulated considerable levels of lipids (i.e., 9.4 ± 1.1, % w/w, and 11.5 ± 0.3, % w/w, respectively) when cultivated under control conditions. Nitrogen limitation affectedboth strains in a negative way as they produced less biomass (i.e., 195.7 ± 10.2 mg L1 for P. oklahomense SAG4.4 while P. oklahomense PAT3.2B gained only 98.0 ± 4.6 mg L-1) and lipids (e.g., P. oklahomense PAT3.2B gained up to 5.1 ± 1.0, % w/w).Under phosphorus limitation, the two strains presented differences in terms of biomass production. P. oklahomense SAG4.4 gained almost 1.8 times higher biomass (i.e. 529.0 ± 36.9 mg L-1), while lipid accumulation was slightly lower (i.e. 5.7 ± 1.6, % w/w) comparing to the control experiment. On the other hand, P. oklahomense PAT3.2B marked low biomass levels (i.e. 125.3 ± 4.1 mg L-1 ) but similar levels of intracellular lipids (i.e. 6.0 ± 2.5, % w/w) comparing to its control experiment. Lastly,the microalgal cell mass in all cases contained proteins (ranging 29.1 – 49.2, % w/w) in considerable levels. The biochemical profiles of the two isolates, especially when cultivated in environment rich in nitrogen and phosphorus, highlight them as suitable candidates for use in various industrial applications.
DGF – 4th ISML – Microalgae
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