Abstract:Some studies have described the use of phytohormones in microalgal culture for the production of biodiesel or selected fatty acids. However, no study has determined the amount of phytohormones that maximizes lipid yield. We determined the optimal concentration of auxins and gibberellins (which is between 40 and 60 μM) in two strains (Scenedemus abundans and Chlorella ellipsoidea) suitable for biodiesel production. More than 3-fold increment was reached with S. abundans and near 7-fold increment with C. ellipso… Show more
“…Our results are consistent with those of a previous report detailing the responses of Scenedesmus abundans and Chlorella ellipsoidea to 2,4-dichlorophenoxyacetic acid (2,4-D) and/or gibberellic acid (GA3) addition [9]. The improved growth of the microalgae in the presence of phytohormones is likely due to a reduction in the level of cellular reactive oxygen species (ROS), whereas high concentrations of phytohormones may behave as herbicides [9]. Fig.…”
Section: Resultssupporting
confidence: 92%
“…Phytohormones are derived from plants and affect plant growth and metabolism [9, 10]. Phytohormones, including auxin, auxinabscisic acid (ABA), cytokinin (CK), ethylene (ET), gibberellins (GAs) and 5-Aminolevulinic acid (5-ALA), have been detected in a variety of microalgal lineages.…”
Section: Introductionmentioning
confidence: 99%
“…However, the functional role of phytohormones in microalgae remains largely underinvestigated. Previous studies have shown that appropriate levels of phytohormones in microalgal culture could promote the production of biomass, biodiesel or selected fatty acids, whereas high concentrations can inhibit production [9]. Thus, optimizing phytohormone levels is necessary to maximize the opportunities for exploiting phytohormones for biotechnological purposes.…”
BackgroundThe microalga Porphyridium purpureum within Rhodophyta abundantly produces several valuable proteins, polysaccharides, pigments and long-chain polyunsaturated fatty acid; it is especially effective in accumulating arachidonic acid (ARA). However, this high ARA yield is always achieved in conditions unfavourable for cell growth. In this study, we present a method for obtaining desirable ARA levels from P. purpureum while simultaneously promoting cell growth using appropriate concentrations of the growth hormone 5-Aminolevulinic acid (5-ALA).ResultsBoth the biomass and the ARA content of P. purpureum were enhanced by stimulation with 20 mg/L 5-ALA, leading to an optimal ARA yield of 170.32 mg/L—a 70.82% increase compared with control conditions. This ARA yield is the highest ever reported for microalgae. Based on variations in the fatty acid composition, total lipids, total proteins, total carbohydrates and pigment content during the cultivation period, we propose that the accumulation of ARA stimulated by 5-ALA occurs at the expense of other UFAs and total proteins, which may be related to decreased zeaxanthin. Lipidomic analysis revealed that triacylglycerols (TAGs) accounted for 47.5 ± 3.6% of all detected lipids, followed by phosphatidylglycerol (PG) and digalactosyldiacylglycerol (DGDG). As the levels of the most abundant TAGs increased under 5-ALA promotion and because 78.1 ± 3.4% (by weight) of detected TAG-branched chains contained ARA, the increase of ARA was mainly caused by TAG accumulation.ConclusionsThis work demonstrated a simple and effective strategy to promote both biomass and ARA yield in P. purpureum by introducing a small amount of 5-ALA. These results are helpful for understanding the microalgae metabolic pathways affected by phytohormones and for guiding the development of bioproducts from microalgae.
“…Our results are consistent with those of a previous report detailing the responses of Scenedesmus abundans and Chlorella ellipsoidea to 2,4-dichlorophenoxyacetic acid (2,4-D) and/or gibberellic acid (GA3) addition [9]. The improved growth of the microalgae in the presence of phytohormones is likely due to a reduction in the level of cellular reactive oxygen species (ROS), whereas high concentrations of phytohormones may behave as herbicides [9]. Fig.…”
Section: Resultssupporting
confidence: 92%
“…Phytohormones are derived from plants and affect plant growth and metabolism [9, 10]. Phytohormones, including auxin, auxinabscisic acid (ABA), cytokinin (CK), ethylene (ET), gibberellins (GAs) and 5-Aminolevulinic acid (5-ALA), have been detected in a variety of microalgal lineages.…”
Section: Introductionmentioning
confidence: 99%
“…However, the functional role of phytohormones in microalgae remains largely underinvestigated. Previous studies have shown that appropriate levels of phytohormones in microalgal culture could promote the production of biomass, biodiesel or selected fatty acids, whereas high concentrations can inhibit production [9]. Thus, optimizing phytohormone levels is necessary to maximize the opportunities for exploiting phytohormones for biotechnological purposes.…”
BackgroundThe microalga Porphyridium purpureum within Rhodophyta abundantly produces several valuable proteins, polysaccharides, pigments and long-chain polyunsaturated fatty acid; it is especially effective in accumulating arachidonic acid (ARA). However, this high ARA yield is always achieved in conditions unfavourable for cell growth. In this study, we present a method for obtaining desirable ARA levels from P. purpureum while simultaneously promoting cell growth using appropriate concentrations of the growth hormone 5-Aminolevulinic acid (5-ALA).ResultsBoth the biomass and the ARA content of P. purpureum were enhanced by stimulation with 20 mg/L 5-ALA, leading to an optimal ARA yield of 170.32 mg/L—a 70.82% increase compared with control conditions. This ARA yield is the highest ever reported for microalgae. Based on variations in the fatty acid composition, total lipids, total proteins, total carbohydrates and pigment content during the cultivation period, we propose that the accumulation of ARA stimulated by 5-ALA occurs at the expense of other UFAs and total proteins, which may be related to decreased zeaxanthin. Lipidomic analysis revealed that triacylglycerols (TAGs) accounted for 47.5 ± 3.6% of all detected lipids, followed by phosphatidylglycerol (PG) and digalactosyldiacylglycerol (DGDG). As the levels of the most abundant TAGs increased under 5-ALA promotion and because 78.1 ± 3.4% (by weight) of detected TAG-branched chains contained ARA, the increase of ARA was mainly caused by TAG accumulation.ConclusionsThis work demonstrated a simple and effective strategy to promote both biomass and ARA yield in P. purpureum by introducing a small amount of 5-ALA. These results are helpful for understanding the microalgae metabolic pathways affected by phytohormones and for guiding the development of bioproducts from microalgae.
“…Falkowska et al (2011) also showed GA3 had a stimulating influence on the cell number in C. vulgaris. Similarly, it was observed that GA treatment increased biomass productivity by 8.7-fold and 5.3-fold, respectively, in C. ellipsoidea and Scenedesmus abundans (González-Garcinuño et al, 2016). In this study, microscopic analysis in the present study showed that application of GA3 significantly affected cell size in C. vulgaris culture (Table 1).…”
Section: Effect Of Gibberellin On Cell Growth and Sizesupporting
Plant growth substances could be stimulating algal growth rate and alter lipid compositions. In the present study, we tested hypothesis that exogenous gibberellin (GA) has any effect on growth rate and some fatty acid profiles in green algae Chlorella vulgaris. In Bold Basal Medium with 100 µM GA 3 , cell density increased to 68.57% on third day as compared to the control cells. These results indicated that GA 3 enhanced microalgal growth and cell size. The lipid profile was also altered compared to control using Gas Chromatography-Mass Spectrometry (GC-MS). GA 3 promotes the production of C16:0, C18:0, C18:1 and C18:3 on day-3 and-5. Under nitrogen starvation condition, application of GA 3 provide enhanced algae growth and stimulated C16:0 and C18:1 production. In conclusion, this study demonstrated that gibberellin could be a good candidate as a hormone for increasing lipid production in microalgae culture system.
“…However, this strategy incurs additional costs and suffers from contamination issues since it involves the supplementation of organic substrates such as glucose, acetate, glycerol, etc. [60,62,[66][67][68].…”
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