Investigating the Effects of Temperature and Carbon Dioxide Levels on Nannochloropsis oceanica Using a Hemocytometer Counting Method
Climate changes that include ocean acidification and global warming are serious problems in the ecosystem, affecting marine phytoplankton, including Nannochloropsis oceanica. In the effort to further explore the impact of rising temperature and carbon dioxide (CO₂) concentrations on oceanic ecosystems, the phytoplankton Nannochloropsis oceanica was used as a model organism. This study explored the effect of temperature change and CO₂ concentration on the growth of Nannochloropsis oceanica, achieving 243 samples that were tested with three different temperatures (24 degrees Celsius (°C), 28°C, 32°C) and CO₂ concentrations (0 milliliter (ml)/min, 0.4 ml/min, 0.6 ml/min), utilizing a hemocytometer counting method. Results indicate that the CO₂ concentration has a significant effect on the population of Nannochloropsis oceanica. But the temperature doesn't affect a lot. The Nannochloropsis oceanica in the lowest temperature and highest concentration of CO₂ in its environment had the highest population growth, and in the highest temperature and lowest concentration of CO₂, it had the lowest population growth. Results show the serious negative effect of climate change on the cosystem and the importance of environmental protection. Population blooms due to excess CO₂ taking up ocean resources causing dangerous ecological imbalances.
果蠅緯度相關晝夜節律特徵:穩定性、活動量分佈與演化意義
Latitude-Dependent Circadian Traits in Drosophila: Stability, Activity Peaks, and Evolutionary Implications
生物時鐘可對生物體的行為與生理造成影響,在探討晝夜節律特徵的差異時,過去研究常侷限於北美大陸的品系,缺少赤道及南半球品系的晝夜節律特徵探討。有鑒於黑腹果蠅在全球各大洲的廣泛分佈,因此我們以黑腹果蠅(近赤道與中高緯度品系)為材料,研究果蠅是否因緯度而有相異的晝夜節律特徵?結果顯示不同緯度的果蠅品系展現出相異的晝夜節律特徵。赤報品系在全暗狀態下仍維持原本光暗12小時的穩定節律,而南北半球的中高緯度品系則具有相似節律特徵,即在全暗狀態下的節律不對齊原本正常光源的穩定節律,其他如活動量、週期、及節律強度等皆有著品系間的差異。更進一步比對實驗中各個品系基因序列,研究發現per和tim在調控區段有許多SNP變異,顯示其與晝夜節律特徵的關係,有助於後續尋找更多造成晝夜節律特徵差異的可能遺傳變異並探討。
橡實代謝物與飛鼠小腸內生菌共發酵產物之應用
This study primarily investigates the components of food residues in the stomach of flying squirrels and the metabolism of the intestinal bacteria Floricoccus tropicus. Using nuclear magnetic resonance (NMR) hydrogen spectrum analysis, the signals of long-chain fatty acids were detected in both n-hexane and 75% ethanol extracts of flying squirrel gastric residues and acorns, suggesting that acorns may be a primary food source for the flying squirrels. The study also identified Floricoccus tropicus, one of the lactic acid bacteria, from the intestines of flying squirrels and discovered its role in the metabolism of fatty acids in acorns. Results showed that polyunsaturated fatty acids significantly decreased during fermentation, indicating that they were converted into short-chain fatty acids with anti-inflammatory properties. In the antibacterial activity experiments, the acorn grease showed no inhibitory effects before fermentation, but after fermentation, the acorn grease exhibited inhibitory effects against E. coli. Furthermore, in anti-inflammatory tests, fermented acorn grease samples significantly suppressed the production of NO and TNF-α in LPSinduced RAW 264.7 cells, with greater inhibition at higher concentrations. In conclusion, the lactic acid bacteria Floricoccus tropicus was found to metabolize fatty acids of acorns into compounds with antibacterial and anti-inflammatory effects.