Two-stage cultivation of N-rich and N-deprived Acutodesmus obliquus biomass: Influence of cultivation and dewatering methods on microalgal biomass used in anaerobic digestion

Gruber-Brunhumer, M.R.; Nussbaumer, M.; Jerney, Jacqueline; Ludwig, Iziar A.; Zohar, E.; Lang, Ingeborg; Bochmann, Günther; Schagerl, Michael; Obbard, Jeffrey Philip; Fuchs, Werner; Drosg, B.

doi:10.1016/j.algal.2016.04.016

Cited by 11 publications

(5 citation statements)

References 33 publications

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“…As previously reported in other oleaginous microalgae [17], the lack of nitrogen inhibits the growth and signi cantly shortens the time required for A. coffeaeformis in the stable phase to enter the recession stage. The growth rate of A. coffeaeformis in f/2-N medium was 0.06 per day and the doubling time extended to 11.67 days (Fig.…”

Section: N Deprivation Restrained the Growth And Physiological Statussupporting

confidence: 62%

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

Wang

Cui

Meng

et al. 2021

Preprint

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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.

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Section: N Deprivation Restrained the Growth And Physiological Statussupporting

confidence: 62%

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

Wang

Cui

Meng

et al. 2021

Preprint

View full text Add to dashboard Cite

show abstract

“…As previously reported in other oleaginous microalgae [19], the lack of nitrogen inhibits the growth and signi cantly shortens the time required for A. coffeaeformis in the stable phase to enter the recession stage. The growth rate of A. coffeaeformis in f/2-N medium was 0.06 per day and the doubling time extended to 11.67 days (Fig.…”

Section: N Deprivation Restrained the Growth And Physiological Statussupporting

confidence: 62%

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

Wang

Cui

Meng

et al. 2021

Preprint

View full text Add to dashboard Cite

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.

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“…The optimum light spectrum varies, as the pigment composition differs between species [34]. The pigment composition also depends on availability of nutrients in the cultivation medium [36,37]. In microalgae cells, pigments are responsible for capturing the light and directing it through the light harvesting complex to chlorophyll a.…”

Section: Lightmentioning

confidence: 99%

“…Furthermore, microalgae biomass represents a promising organic source to produce biogas [82]. Anaerobic digestion of Acutodesmus obliquus biomass obtained a CH 4 yield of 200-391 Nm 3 t −1 VS, and the maximal yield was achieved through digestion of biomass with increased lipid content (+20%, in total 30% TS, due to nitrogen deprivation) [37]. Synechocystis cf.…”

Section: Bioenergy Productionmentioning

confidence: 99%

Digestate as Sustainable Nutrient Source for Microalgae—Challenges and Prospects

et al. 2021

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The interest in microalgae products has been increasing, and therefore the cultivation industry is growing steadily. To reduce the environmental impact and production costs arising from nutrients, research needs to find alternatives to the currently used artificial nutrients. Microalgae cultivation in anaerobic effluents (more specifically, digestate) represents a promising strategy for increasing sustainability and obtaining valuable products. However, digestate must be processed prior to its use as nutrient source. Depending on its composition, different methods are suitable for removing solids (e.g., centrifugation) and adjusting nutrient concentrations and ratios (e.g., dilution, ammonia stripping). Moreover, the resulting cultivation medium must be light-permeable. Various studies show that growth rates comparable to those in artificial media can be achieved when proper digestate treatment is used. The necessary steps for obtaining a suitable cultivation medium also depend on the microalgae species to be cultivated. Concerning the application of the biomass, legal aspects and impurities originating from digestate must be considered. Furthermore, microalgae species and their application fields are essential criteria when selecting downstream processing methods (harvest, disintegration, dehydration, product purification). Microalgae grown on digestate can be used to produce various products (e.g., bioenergy, animal feed, bioplastics, and biofertilizers). This review gives insight into the origin and composition of digestate, processing options to meet requirements for microalgae cultivation and challenges regarding downstream processing and products.

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Two-stage cultivation of N-rich and N-deprived Acutodesmus obliquus biomass: Influence of cultivation and dewatering methods on microalgal biomass used in anaerobic digestion

Cited by 11 publications

References 33 publications

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

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

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

Digestate as Sustainable Nutrient Source for Microalgae—Challenges and Prospects

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