Nannochloropsis oculata CS-179, a marine eukaryotic unicellular microalga, is rich in long-chain polyunsaturated fatty acids (LC-PUFAs). Culture temperature affected cell growth and the composition of LC-PUFAs. At an ...Nannochloropsis oculata CS-179, a marine eukaryotic unicellular microalga, is rich in long-chain polyunsaturated fatty acids (LC-PUFAs). Culture temperature affected cell growth and the composition of LC-PUFAs. At an initial cell density of 1.5 × 106 cell mL-1, the highest growth was observed at 25℃ and the cell density reached 3 × 107 cell mL-1 at the beginning of loga-rithmic phase. The content of LC-PUFAs varied with culture temperature.The highest content of LC-PUFAs (43.96%) and EPA (36.6%) was gained at 20℃. Real-time PCR showed that the abundance of Δ6-desaturase gene transcripts was significantly different among 5 culture temperatures and the highest transcript level (15℃) of Nanoc-D6D took off at cycle 21.45. The gene transcript of C20-elongase gene was higher at lower temperatures (10, 15, and 20℃), and the highest transcript level (20℃) of Nanoc-E took off at cycle 21.18. The highest conversion rate (39.3%) of Δ6-desaturase was also gained at 20℃.But the conversion rate of Nanoc-E was not detected. The higher content of LC-PUFAs was a result of higher gene transcript level and higher enzyme activity. Compared with C20-elongase gene, Δ6-desaturase gene transcript and enzyme activity varied significantly with temperature. It will be useful to study the mechanism of how the content of LC-PUFAs is affected by temperature.展开更多
基金supported by the grants from the National Key Technologies Research and Development Program of China during the Eleventh Five-Year Plan Period(No.2006BAD09A03-2)National High Technology Research and Development Program of China(863 Program)(No.2007AA09Z427)Basic Research Program of Municipal Bureau of Science and Technology of Qingdao(No.09-1-3-22-jch)
文摘Nannochloropsis oculata CS-179, a marine eukaryotic unicellular microalga, is rich in long-chain polyunsaturated fatty acids (LC-PUFAs). Culture temperature affected cell growth and the composition of LC-PUFAs. At an initial cell density of 1.5 × 106 cell mL-1, the highest growth was observed at 25℃ and the cell density reached 3 × 107 cell mL-1 at the beginning of loga-rithmic phase. The content of LC-PUFAs varied with culture temperature.The highest content of LC-PUFAs (43.96%) and EPA (36.6%) was gained at 20℃. Real-time PCR showed that the abundance of Δ6-desaturase gene transcripts was significantly different among 5 culture temperatures and the highest transcript level (15℃) of Nanoc-D6D took off at cycle 21.45. The gene transcript of C20-elongase gene was higher at lower temperatures (10, 15, and 20℃), and the highest transcript level (20℃) of Nanoc-E took off at cycle 21.18. The highest conversion rate (39.3%) of Δ6-desaturase was also gained at 20℃.But the conversion rate of Nanoc-E was not detected. The higher content of LC-PUFAs was a result of higher gene transcript level and higher enzyme activity. Compared with C20-elongase gene, Δ6-desaturase gene transcript and enzyme activity varied significantly with temperature. It will be useful to study the mechanism of how the content of LC-PUFAs is affected by temperature.
