Fernández L, Scher H, VanderGheynst J S
Department of Biological and Agricultural Engineering, University of California, Davis, CA, USA.
Bayer Crop Science, Davis, CA, USA.
Lett Appl Microbiol. 2015 Dec;61(6):568-72. doi: 10.1111/lam.12494. Epub 2015 Nov 2.
Prior research has demonstrated that microalgae can be stored for extended periods of time at room temperature in water-in-oil (W/O) emulsions stabilized by surface modified silica nanoparticles. However, little research has been done to examine the impact of nanoparticle concentration on emulsion stability. Such information is important for large-scale production of emulsions for microalgae storage and delivery. Studies were done to examine the impact of silica nanoparticle concentration on emulsion stability and identify the lower limit for nanoparticle concentration. Emulsion physical stability was determined using internal phase droplet size measurements and biological stability was evaluated using cell density measurements. The results demonstrate that nanoparticle concentrations as low as 0·5wt% in the oil phase can be used without significant losses in emulsion stability and microalgae viability.
Stabilization technologies are needed for long-term storage and application of microalgae in agricultural-scale systems. While prior work has demonstrated that water-in-oil emulsions containing silica nanoparticles offer a promising solution for long-term microalgae storage at room temperature, little research has been done to examine the impact of nanoparticle concentration on emulsion stability. Here, we show the effects of silica nanoparticle concentration on maintaining physical stability of emulsions and sustaining viable cells. The results enable informed decisions to be made regarding production of emulsions containing silica nanoparticles and associated impacts on stabilization of microalgae.
先前的研究表明，微藻可以在由表面改性二氧化硅纳米颗粒稳定的油包水（W/O）乳液中于室温下长期储存。然而，关于纳米颗粒浓度对乳液稳定性的影响，所做的研究很少。此类信息对于大规模生产用于微藻储存和递送的乳液很重要。开展了相关研究以考察二氧化硅纳米颗粒浓度对乳液稳定性的影响，并确定纳米颗粒浓度的下限。通过测量内相液滴尺寸来确定乳液的物理稳定性，通过测量细胞密度来评估生物稳定性。结果表明，油相中低至0.5wt%的纳米颗粒浓度即可使用，而不会导致乳液稳定性和微藻活力出现显著损失。
在农业规模系统中，微藻的长期储存和应用需要稳定化技术。虽然先前的工作表明，含有二氧化硅纳米颗粒的油包水乳液为室温下微藻的长期储存提供了一种有前景的解决方案，但关于纳米颗粒浓度对乳液稳定性的影响，所做的研究很少。在此，我们展示了二氧化硅纳米颗粒浓度对维持乳液物理稳定性和保持活细胞的影响。这些结果有助于就含二氧化硅纳米颗粒乳液的生产及其对微藻稳定化的相关影响做出明智决策。
