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.

Microalgal Biodiesel Production: Realizing the Sustainability Index

Search for new and renewable sources of energy has made research reach the tiny little tots, microalgae for the production of biodiesel. But despite years of research on the topic, a definitive statement, declaring microalgae as an economically, environmentally, and socially sustainable resource is yet to be seen or heard of. With technological and scientific glitches being blamed for this delay in the progress of the production system, an assessment of the sustainability indices achieved so far by the microalgal biodiesel is important to be done so as to direct future research efforts in a more coordinated manner to achieve the sustainability mark. This article provides a review of the current economic, environmental, and social status of microalgal biodiesel and the strategies adopted to achieve them, with suggestions to address the challenges faced by the microalgal biodiesel production system.

An Assessment Of Microalgal Biodiesel With Acetone, Butanol and Ethanol Using LIfe Cycle Assessment (LCA) Methodology

Canada, as one of the largest producers and consumers of fossil fuels per capita on the planet, is attempting to reduce greenhouse gas (GHG) emissions. In order to accomplish this, fuel alternatives, such as biofuel, are required. Accordingly, this study uses LCA methodology to quantify the GHG impact of a unique biofuel production model. This unique model produces biodiesel (BD), acetone, butanol and ethanol (ABE) from microalgae and assesses the process GHG impact against other microalgal BD production processes. This study’s microalgal BD and ABE production process produces 76 kgCO2e per functional unit, whereas other comparable microalgal BD production processes produce between 3.7 and 85 kgCO2e. Overall, this study clarifies that without the development of versatile infrastructure to accommodate biofuel production, LCA studies will continue to find renewable fuel production processes net GHG positive for the simple reason that fossil resources are still the primary energy source.

An Assessment Of Microalgal Biodiesel With Acetone, Butanol and Ethanol Using LIfe Cycle Assessment (LCA) Methodology

Canada, as one of the largest producers and consumers of fossil fuels per capita on the planet, is attempting to reduce greenhouse gas (GHG) emissions. In order to accomplish this, fuel alternatives, such as biofuel, are required. Accordingly, this study uses LCA methodology to quantify the GHG impact of a unique biofuel production model. This unique model produces biodiesel (BD), acetone, butanol and ethanol (ABE) from microalgae and assesses the process GHG impact against other microalgal BD production processes. This study’s microalgal BD and ABE production process produces 76 kgCO2e per functional unit, whereas other comparable microalgal BD production processes produce between 3.7 and 85 kgCO2e. Overall, this study clarifies that without the development of versatile infrastructure to accommodate biofuel production, LCA studies will continue to find renewable fuel production processes net GHG positive for the simple reason that fossil resources are still the primary energy source.