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- Vaiciulyte, Sigita, 1988, et al.
(author)
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Sufficient CO2 concentration is crucial for high biomass formation of marine microalgae
- 2015
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In: Proceedings of 4th Latin-American Society of Environmental and Algal Biotechnology Congress (SOLABIAA), November 8-13, Brazil.
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Conference paper (peer-reviewed)abstract
- The effect of low and high CO2 concentration for the growth of marine green microalgae genera Chlorella and Picochlorum were investigated. Chlorella sp. A, Chlorella sp. B, Chlorella sp. C and Picochlorum sp. strains were grown in a batch culture under 20:4 hours of light:dark photoperiods and with either 0.035 % (ambient air) or 2.0 % of CO2 supply. Picochlorum sp. and Chlorella sp. C achieved the highest maximum growth rate (d-1) 1.06 and 1.05, respectively, when cultured with a high CO2 supply (2.0 %). Cultures supplied with low CO2 (0.035 %), did not enter into exponential growth phase, but formed biomass in a steady linear growth pattern, suggesting significant carbon limitation. Thus, it is clear that the supply of CO2 is critical for high rates of microalgal biomass production, and optimal CO2 ¬supply rate should be identified that also improves carbohydrate formation.
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| 2. |
- Mayers, Joshua, 1988, et al.
(author)
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An approaching global phosphorus crisis and microalgal biotechnology: A growing problem & strategies for effective use
- 2015
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Conference paper (other academic/artistic)abstract
- Phosphorus (P) is a critical element for life on Earth. However, readily extractable ores are being exhausted rapidly and a combination of increasing usage, rising costs and numerous geopolitical problems are expected to impact food security and industry sectors within the next few decades. This hence represents another great anthropogenic challenge and near-future issue. P is needed in the production of microalgal biomass; indeed the value of P in microalgae is similar or exceeds that of the potential biofuels, demanding a 100% recovery and recycling of P. However, unlike nitrogen (N) sources (that can be synthesised) for which the relationship of cell-contents and growth is linear, the need for P is less clearly understood. We have empirically explored the interaction between P supply and microalgal production and biochemical composition. P usage could be at least halved relative to the use of N, while maintaining adequate growth of Nannochloropsis. Indeed, by deploying certain strategies, the amount of P required to produce 1 kg of biomass can be decreased from 2.4 g to 0.85 g (65% reduction). The quantitative effects of dual N- and P-limitation on biochemical composition, fatty acid profile and biodiesel quality were also evaluated in a greater detail than has previously been reported. The replacement of inorganic nutrients with those obtained from waste nutrient streams was examined and also proved to be a successful strategy in decreasing resource consumption. P usage in the broader context of large-scale microalgal cultivation will be put into context with information critical for algal physiology, practitioners and LCA development.
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| 4. |
- Veide Vilg, Jenny, 1973, et al.
(author)
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Seasonal and spatial variation in biochemical composition of Saccharina latissima during a potential harvesting season for Western Sweden
- 2015
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In: Botanica Marina. - : Walter de Gruyter GmbH. - 0006-8055 .- 1437-4323. ; 58:6, s. 435-447
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Journal article (peer-reviewed)abstract
- This study monitored the biomass composition of Saccharina latissima during a potential harvesting season on the West coast of Sweden, in order to find suitable harvest times for biorefinery purposes. Specimens of S. latissima were sampled at three locations in June, August and October and the biomass was analysed for its macromolecular composition, as well as for the content of several specific compounds, e.g. sugars and fatty acids. PERMANOVA analyses showed that there was a significant difference in the biomass composition among time points. The total carbohydrate concentration was lowest in June and peaked at 360 mg g-1 dry weight in August, while the mannitol content was highest, 90 mg g-1, in June and decreased throughout the sampling period. Total protein and fatty acid concentrations were found to be approximately 80 and 3 mg g-1, respectively, with relatively little variation over time. Overall, there was little spatial variation in the macromolecular composition, although the concentration of some specific monosaccharides and fatty acids, as well as the total phenolic content, differed among localities. We discuss the implications of the observed variation in biomass composition of S. latissima for future biorefinery purposes.
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