Nitrogen Deficiency in Culture Affects the Metabolic Pathways in Amphora Coffeaeformis for Biodiesel Production

Background: Amphora coffeaeformis, a unicellular diatom, can accumulate large amounts of lipids under nitrogen (N) limitation, because of which it can act as a promising raw material for biodiesel production. However, the molecular mechanism underlying lipid accumulation in A. coffeaeformis remains unknown. Results: In this study, we investigated the mechanism underlying lipid accumulation under N deprivation conditions in A. coffeaeformis using RNA-seq. The results showed that the total lipid (TL) content of A. coffeaeformis in normal f/2 medium was 28.22% (TL/DW), which increased to 44.05% after 5 days of N deprivation, while the neutral lipid triacylglycerol (TAG) content increased from 10.41% (TAG/DW) to 25.21%. The transcriptional profile showed that 591 genes were up-regulated, with false discovery rate cutoff of 0.1%, and 1,021 genes were down-regulated, indicating that N deprivation induced wide-ranging reprogramming of regulation, and that most physiological activities were repressed. In addition, ribosome biogenesis, carbon fixation, and photosynthesis in A. coffeaeformis were considerably affected by N deprivation. Conclusions: In summary, the findings initially clarified the molecular mechanism of TAG accumulation and revealed the key genes involved in lipid metabolism in A. coffeaeformis, which will be useful in designing strategies for improving microalgal biodiesel production.

Nitrogen Deficiency in Culture Affects the Metabolic Pathways in Amphora Coffeaeformis for Biodiesel Production

BackgroundAmphora coffeaeformis, a unicellular diatom, can accumulate large amounts of lipids under nitrogen (N) limitation, because of which it can act as a promising raw material for biodiesel production. However, the molecular mechanism underlying lipid accumulation in A. coffeaeformis remains unknown. ResultsIn this study, we investigated the mechanism underlying lipid accumulation under N deprivation conditions in A. coffeaeformis using RNA-seq. The results showed that the total lipid (TL) content of A. coffeaeformis in normal f/2 medium was 28.22% (TL/DW), which increased to 44.05% after 5 days of N deprivation, while the neutral lipid triacylglycerol (TAG) content increased from 10.41% (TAG/DW) to 25.21%. The transcriptional profile showed that 591 genes were up-regulated, with false discovery rate cutoff of 0.1%, and 1,021 genes were down-regulated, indicating that N deprivation induced wide-ranging reprogramming of regulation, and that most physiological activities were repressed. In addition, ribosome biogenesis, carbon fixation, and photosynthesis in A. coffeaeformis were considerably affected by N deprivation. ConclusionsIn summary, the findings shed light on the molecular mechanisms of neutral lipid accumulation and revealed the key genes involved in lipid metabolism in A. coffeaeformis, which will be useful in designing strategies for improving microalgal biodiesel production.

Microplastics induced endocrine disruption, alteration in testicular tissue in tilapia (Oreochromis niloticus) pre-fed on Amphora coffeaeformis

This study examines the potential defending effects of the diatom, Amphora coffeaeformis, as a feed additive against the deleterious effects (mainly on gonads) caused by microplastics (MPs) in the Nile tilapia, Oreochromes niloticus. Male tilapia groups were pre-fed diets with four different supplementation levels of A. coffeaeformis (0%, 2.5%, 5% and 7.5%) for 70 days, then were exposed to 10 mg/L MPs for 15 days. The results showed significantly (p < 0.05) higher numbers of erythrocytes, but significant decreases (p < 0.05) in the number of RBCs, Hb, Ht, platelets, and eosinophil percentages. Testicular histological degenerative changes and testis-ova were found in the MPs-exposed fish. Thus, A. coffeaeformis supplementation displayed ameliorative properties that detoxified the negative effects of MPs. This study provides a better understanding of the reproductive injuries caused by MPs and provides evidence for the use of A. coffeaeformis as a natural remedy in freshwater tilapia.

The potential neuroprotective role of Amphora coffeaeformis algae against monosodium glutamate-induced neurotoxicity in adult albino rats

The current study provides a novel approach for treating monosodium glutamate neurotoxicity using safely cultivated Amphora coffeaeformis algae.