Yoo Chan, La Hyun-Joon, Kim Sun-Chang, Oh Hee-Mock
Environmental Biotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 305-806, Korea; Department of Biological Science, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea.
Biotechnol Bioeng. 2015 Feb;112(2):288-96. doi: 10.1002/bit.25362. Epub 2014 Oct 10.
Microalgae cultures show wide range of pH depending on the availability of light and CO2 for their strain specific photosynthesis. Thus, the modulation of light irradiation and CO2 supply can be applied for the pH control of microalgae cultures. The optimal pH of Ettlia sp. YC001, for phototrophic growth and auto-flocculation was investigated by controlling light irradiation and 10% CO2 supply. Ettlia sp. YC001 showed the highest biomass productivity, 96.7 mg L(-1) d(-1) , at pH 8.5. The flocculating activity of Ettlia sp. YC001 showed a sigmoid pattern with pH increase and was above 70% at pH 10.5. Based on these differentiated optimal pH regimes for the growth and flocculation, an integrated process consisting of cultivation and settling vessels was proposed. The integrated process demonstrated that high flocculation activity of Ettlia sp. YC001 could be achieved in the settling vessel with various hydraulic retention times by only irradiation of light to maintain high pH while maintaining the optimal growth in cultivation vessel with the light irradiation and CO2 supply at pH 8.5. Thus, the proposed strategy for pH control would provide a simple, cost-effective, and flexible design and operation for microalgae cultivation-harvest systems.
微藻培养物的pH值范围很广，这取决于光照和二氧化碳的可利用性，以满足其特定菌株的光合作用。因此，调节光照和二氧化碳供应可用于控制微藻培养物的pH值。通过控制光照和10%的二氧化碳供应，研究了Ettlia sp. YC001在光合生长和自动絮凝方面的最佳pH值。Ettlia sp. YC001在pH值为8.5时表现出最高的生物质生产力，即96.7 mg L(-1) d(-1)。Ettlia sp. YC001的絮凝活性随pH值升高呈S形模式，在pH值为10.5时高于70%。基于生长和絮凝的这些不同最佳pH值范围，提出了一个由培养和沉降容器组成的集成工艺。该集成工艺表明，通过仅照射光线以维持高pH值，同时在pH值为8.5的条件下通过光照和二氧化碳供应在培养容器中维持最佳生长，Ettlia sp. YC001在具有不同水力停留时间的沉降容器中可实现高絮凝活性。因此，所提出的pH值控制策略将为微藻培养-收获系统提供简单、经济高效且灵活的设计和操作。
