Graduate Institute of Biomedical Engineering, National Central University, Jhongli City, Taoyuan County, Taiwan, ROC.
Bioprocess Biosyst Eng. 2013 Aug;36(8):1071-8. doi: 10.1007/s00449-012-0860-8. Epub 2012 Nov 20.
The commercial value of marine Nannochloropsis oculata has been recognized due to its high content of eicosapentaenoic acid (>50% w/w). To make it as a profitable bioresource, one of the most desirable goals is to develop a quality-controlled, cost-effective, and large-scale photobioreactor for N. oculata growth. Generally, closed culture system can offer many advantages over open system such as small space requirement, controllable process and low risk of contamination. However, oxygen accumulation is often a detrimental factor for enclosed microalgal culture that has seriously hampered the development of microalga-related industries. In this study, we proposed to use fluorochemical as oxygen carrier to overcome the challenge where four liquid fluorochemicals namely perfluorooctyl bromide, perfluorodecalin, methoxynonafluorobutane, and ethoxynonafluorobutane were investigated separately. Our results showed that the microalgal proliferation with different fluorinated liquids was similar and comparable to the culture without a fluorochemical. When cultured in the photobioreactor with 60% oxygen atmosphere, the N. oculata can grow up in all the fluorochemical photobioreactors, but completely inhibited in the chamber without a fluorochemical. Moreover, the perfluorooctyl bromide system exhibited the most robust efficacy of oxygen removal in the culture media (perfluorooctyl bromide > perfluorodecalin > methoxynonafluorobutane > ethoxynonafluorobutane), and yielded a >3-fold increase of biomass production after 5 days. In summary, the developed fluorochemical photobioreactors offer a feasible means for N. oculata growth in closed and large-scale setting without effect of oxygen inhibition.
商业价值已认可海洋眼点拟微绿球藻由于其高含量的二十碳五烯酸（> 50%w/w）。为了使其成为一种有利可图的生物资源，最理想的目标之一是开发一种质量可控、成本效益高、规模化的光生物反应器用于眼点拟微绿球藻的生长。一般来说，封闭培养系统相对于开放系统具有许多优势，如空间需求小、过程可控、污染风险低。然而，氧气积累通常是封闭微藻培养的一个不利因素，严重阻碍了微藻相关产业的发展。在这项研究中，我们提出使用氟化学物质作为氧载体来克服这一挑战，分别研究了四种液体氟化学物质，即全氟辛基溴、全氟癸烷、甲氧基全氟丁烷和乙氧基全氟丁烷。我们的结果表明，不同氟代液体对微藻增殖的影响相似，与无氟代化学物质的培养相当。在 60%氧气气氛的光生物反应器中培养时，眼点拟微绿球藻可以在所有含氟光生物反应器中生长，但在没有氟代化学物质的腔室内完全受到抑制。此外，全氟辛基溴体系在培养基中表现出最强的除氧效果（全氟辛基溴>全氟癸烷>甲氧基全氟丁烷>乙氧基全氟丁烷），并在 5 天后使生物量产量增加了 3 倍以上。总之，开发的氟化学光生物反应器为眼点拟微绿球藻在封闭和大规模环境中的生长提供了一种可行的方法，而不会受到氧气抑制的影响。
