Christina Samara, Alexandros Biziouras, Georgia Papapanagiotou, Christos Chatzidoukas
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引用次数: 0
Abstract
The microalga Haematococcus pluvialis can accumulate the natural antioxidant astaxanthin up to 5 % of its dry weight under multi-stress conditions. Increasing this percentage remains challenging; therefore, the key to efficient astaxanthin production lies significantly on the formation of a vigorous, high-density, and synchronized green-cell population prior to the induction of carotogenesis. Despite its importance, optimization of the vegetative growth phase is often underestimated. This study employs an L9-Taguchi design of experiments to systematically investigate the combinatorial effects of four key cultivation factors - temperature, sodium bicarbonate, nitrogen, and phosphorus - on the vegetative growth of H. pluvialis. Temperature emerges as the most influential factor for biomass production, showing an adverse effect with its increment. Nitrogen and phosphorus limitation combined with sodium bicarbonate supplementation induces a premature shift to the non-proliferative red stage. Overall, the optimal conditions identified for vegetative stage maintenance and biomass maximization are: 22 °C, 250 mg L−1 sodium bicarbonate, 150 mg L−1 nitrogen and 40 mg L−1 phosphorus. These conditions result in the production of 1.53 g L−1 green dry biomass after 15 days of cultivation, outperforming by 0.3 g L−1 suboptimal green phase conditions. Post-verification of the Taguchi-derived predictions is experimentally demonstrated paving the way for the formulation of dense and robust green-cell populations that will be concomitantly transferred to the red stage.
期刊介绍:
The Biochemical Engineering Journal aims to promote progress in the crucial chemical engineering aspects of the development of biological processes associated with everything from raw materials preparation to product recovery relevant to industries as diverse as medical/healthcare, industrial biotechnology, and environmental biotechnology.
The Journal welcomes full length original research papers, short communications, and review papers* in the following research fields:
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Bioseparations including scale-up and protein refolding/renaturation
Environmental Bioengineering including bioconversion, bioremediation, and microbial fuel cells
Bioreactor Systems including characterization, optimization and scale-up
Bioresources and Biorefinery Engineering including biomass conversion, biofuels, bioenergy, and optimization
Industrial Biotechnology including specialty chemicals, platform chemicals and neutraceuticals
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Cell Therapies and Stem Cells including pluripotent, mesenchymal and hematopoietic stem cells; immunotherapies; tissue-specific differentiation; and cryopreservation
Metabolic Engineering, Systems and Synthetic Biology including OMICS, bioinformatics, in silico biology, and metabolic flux analysis
Protein Engineering including enzyme engineering and directed evolution.