Presentation Information
[P04-569]Enhancement of glycoshingolipid production from the green alga Tetraselmis sp. NKG400013
○Harumi Matsushime1 (1. Tokyo University of Agriculture and Technology (Japan))
Keywords:
glycosylceramide,sphingolipid metabolism,marine microalgae
Purpose
Glycosphingolipids (GSLs) are complex lipids widely used in pharmaceuticals and cosmetics. They are currently produced industrially from soybean and wheat. However, the GSL contents are relatively low, so alternative sources are being explored. We have isolated a novel GSL producer, the green microalga Tetraselmis sp. NKG400013. It possesses the highest GSL content among photosynthetic organisms (0.67 mg/g dry weight).strategies to enhance glycosphingolipid productivity in microalgae have not yet been established. This study aimed to evaluate the optimization of culture conditions to improve GSL productivity in Tetraselmis sp. NKG400013.
Method
Tetraselmis sp. NKG400013 was cultured for 8 days in modified IMK media with varying nitrate and phosphate concentrations. In addition to photoautrophic conditions, mixotrophic conditions were examined by supplementing the nutrient-enriched modified IMK medium with glucose (1 and 5 g/l) or sodium acetate (0.5, 1, 1.5, and 2 g/l). Lipids were extracted from dry biomass, separated by thin-layer chromatography (TLC), and GSLs were quantified using the orcinol–sulfuric acid method. GSL productivity was assessed based on both biomass yield and glycosphingolipid content per dry weight.
Results, Consideration
Among the nutrient conditions examined, the medium containing four-fold nitrate and two-fold phosphate concentrations produced the highest biomass yield, approximately twice that of the standard IMK medium. On the other hand, GSL content remained unchanged under these nutrient conditions.Under mixotrophic cultivation with glucose supplementation, no significant increase in biomass yield was observed, and glycosphingolipid content showed only a modest improvement (1.2-fold). In contrast, sodium acetate supplementation significantly enhanced GSL accumulation. The highest GSL content was observed at 1 g/l sodium acetate, reaching 2.31 mg/g dry biomass, corresponding to 1.7-fold increase relative to the condition prior to sodium acetate supplementation. Biomass yield was not significantly affected by acetate addition.In summary, optimization of the cultivation process resulted in a maximum 4.7-fold increase in total GSL production compared with the initial condition. Sodium acetate supplementation markedly enhanced glycosphingolipid accumulation, suggesting that acetate contributed to lipid biosynthesis.
Conclusion
Optimization of nutrient composition and carbon source supplementation significantly improved glycosphingolipid production in Tetraselmis sp. NKG400013. In particular, sodium acetate supplementation effectively enhanced GSL accumulation, resulting in 4.7-fold increase in overall production. These results demonstrate that Tetraselmis sp. NKG400013 is a promising platform for efficient GSL production and provide a foundation for future industrial applications.
Glycosphingolipids (GSLs) are complex lipids widely used in pharmaceuticals and cosmetics. They are currently produced industrially from soybean and wheat. However, the GSL contents are relatively low, so alternative sources are being explored. We have isolated a novel GSL producer, the green microalga Tetraselmis sp. NKG400013. It possesses the highest GSL content among photosynthetic organisms (0.67 mg/g dry weight).strategies to enhance glycosphingolipid productivity in microalgae have not yet been established. This study aimed to evaluate the optimization of culture conditions to improve GSL productivity in Tetraselmis sp. NKG400013.
Method
Tetraselmis sp. NKG400013 was cultured for 8 days in modified IMK media with varying nitrate and phosphate concentrations. In addition to photoautrophic conditions, mixotrophic conditions were examined by supplementing the nutrient-enriched modified IMK medium with glucose (1 and 5 g/l) or sodium acetate (0.5, 1, 1.5, and 2 g/l). Lipids were extracted from dry biomass, separated by thin-layer chromatography (TLC), and GSLs were quantified using the orcinol–sulfuric acid method. GSL productivity was assessed based on both biomass yield and glycosphingolipid content per dry weight.
Results, Consideration
Among the nutrient conditions examined, the medium containing four-fold nitrate and two-fold phosphate concentrations produced the highest biomass yield, approximately twice that of the standard IMK medium. On the other hand, GSL content remained unchanged under these nutrient conditions.Under mixotrophic cultivation with glucose supplementation, no significant increase in biomass yield was observed, and glycosphingolipid content showed only a modest improvement (1.2-fold). In contrast, sodium acetate supplementation significantly enhanced GSL accumulation. The highest GSL content was observed at 1 g/l sodium acetate, reaching 2.31 mg/g dry biomass, corresponding to 1.7-fold increase relative to the condition prior to sodium acetate supplementation. Biomass yield was not significantly affected by acetate addition.In summary, optimization of the cultivation process resulted in a maximum 4.7-fold increase in total GSL production compared with the initial condition. Sodium acetate supplementation markedly enhanced glycosphingolipid accumulation, suggesting that acetate contributed to lipid biosynthesis.
Conclusion
Optimization of nutrient composition and carbon source supplementation significantly improved glycosphingolipid production in Tetraselmis sp. NKG400013. In particular, sodium acetate supplementation effectively enhanced GSL accumulation, resulting in 4.7-fold increase in overall production. These results demonstrate that Tetraselmis sp. NKG400013 is a promising platform for efficient GSL production and provide a foundation for future industrial applications.
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