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首页> 外文学位 >Biological Stability and Delivery Studies to Elucidate the Role of Thickener Solid Particles on Water-in-Oil Emulsion Containing Microalgae.
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Biological Stability and Delivery Studies to Elucidate the Role of Thickener Solid Particles on Water-in-Oil Emulsion Containing Microalgae.

机译：阐明增稠剂固体颗粒在含微藻油包水乳液中作用的生物学稳定性和传递研究。

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摘要

The main goal of this dissertation was to study and modify water-in-oil (W/O) emulsions to obtain a predictable storage and delivery system for algae. Water-in-oil emulsions were prepared with different concentrations of the following three thickeners in the oil phase: Aerosil R974 (silica nanoparticles), Bentone 38 (hectorite clay), and Bentone 150 (Bentonite clay). Room temperature storage stability and cell viability in emulsions were measured. Emulsions prepared with different thickeners did not experience cell death up to 340 days of storage. Emulsions containing different concentrations of thickener did not show a statistical difference in cell viability up to 305 days of storage. Emulsions with different thickeners were physically stable likely due to the formation of stable networks in the oil phase and increase in stabilization of the water--oil interface facilitated by the thickeners. Physical stability (prevention of algae settling and clumping) of the emulsions led to biological stability of the algae. Release rate of the aqueous internal phase of W/O emulsions was determined for emulsions containing different thickeners in the oil phase.;Release rate was measured by adding fluorescent Brilliant Sulfaflavine (BSF) in the aqueous phase of the emulsion. Emulsions containing 0.5wt% thickener in the oil phase were sprayed into plastic tubs. Maximum release of the internal phase of the emulsion containing BSF was observed within 8 hours of application. For emulsions containing BSF, Bentone 150 had the highest release rate after 30 minutes of application followed by Bentone 38, Aerosil R974, and finally emulsions without thickener. Release rates of algae from emulsions formulated with different thickeners and no thickener were not statistically different. Recovery of the internal phase containing BSF from the emulsion was done using the drop method (average droplet size equals ∼2mm), which has been used to determine cell viability in emulsions during storage. It was determined that this method has a very low percent recovery of the internal phase indicating that the creation of more surface area in the form of small drops, such as those created by spray equipment, is necessary to have a higher release rate of the internal phase. The release rate from the W/O emulsion was significantly improved when the formulation was sprayed (average droplet size equals ∼45microm). Emulsions sprayed into containers with N-8 growth media released enough cells to serve as inoculum for a successful growth culture. The data support the use of W/O emulsions as a seed technology for algae cultivation.;Successful cell storage technologies must maintain cell viability and physical stability for extended periods of time under varying temperatures. In addition to understanding how physical and biological stability are influenced by storage temperature, it is important to determine if the emulsion provides protection to cells upon extended exposure to lethal temperatures. Emulsions containing Chlorella sorokiniana and Chlorella minutissima were formulated with different thickeners (silica nanoparticles and Bentone 38) in the oil phase and cell viability at high temperatures was compared to unformulated cell suspensions. Emulsions provided Chlorella sorokiniana protection to exposure to 42°C after 24 hours. Emulsions containing silica nanoparticles showed prolonged temperature protection after 72 hours. At 46.5°C cell inactivation was greater for cells in cell suspension and in emulsions formulated with Bentone 38 compared to emulsions formulated with silica. Cell suspension containing Chlorella minutissima had a faster inactivation constant at 38°C and 42°C compared to emulsions containing silica nanoparticles and Bentone 38. At 38°C cells in emulsions containing silica nanoparticles had slower death rates and they were less susceptible to heat over time. At 42°C after 8 hours of heat exposure, emulsions formulated with silica nanoparticles showed a notable protection against cell inactivation. (Abstract shortened by UMI.).
机译：本文的主要目的是研究和改进油包水乳状液，以获得可预测的藻类储藏和输送系统。用不同浓度的以下三种增稠剂在油相中制备油包水乳液：Aerosil R974（二氧化硅纳米颗粒），Bentone 38（锂蒙脱石粘土）和Bentone 150（膨润土）。测量了室温下乳液中的储存稳定性和细胞活力。使用不同的增稠剂制备的乳液在储存340天后不会发生细胞死亡。含有不同浓度的增稠剂的乳剂在储存305天后并未显示出细胞活力的统计学差异。使用不同增稠剂的乳液在物理上很稳定，这可能是由于在油相中形成了稳定的网络，并且增稠剂促进了水-油界面的稳定性增加。乳剂的物理稳定性（防止藻类沉淀和结块）导致藻类的生物稳定性。对于在油相中含有不同增稠剂的乳液，确定了W / O乳液的水内相的释放速率。通过在乳液的水相中添加荧光辉石磺胺黄酮（BSF）来测量释放速率。将油相中含有0.5wt％增稠剂的乳液喷入塑料桶中。在施用的8小时内观察到含有BSF的乳液的内相的最大释放。对于含有BSF的乳液，在施用30分钟后，Bentone 150的释放速率最高，其次是Bentone 38，Aerosil R974，最后是没有增稠剂的乳液。藻类从不同增稠剂和无增稠剂配制的乳液中的释放速率在统计学上没有差异。使用滴落法（平均液滴大小约等于2mm）从乳液中回收含BSF的内相，该方法已用于确定储存过程中乳液中的细胞活力。已确定该方法对内相的回收率非常低，这表明必须以小滴形式（例如由喷雾设备产生的小滴）形成更多的表面积，以提高内部释放速率。相。喷雾制剂时，W / O乳液的释放速率得到了显着提高（平均液滴尺寸约为45微米）。喷雾到装有N-8生长培养基的容器中的乳剂释放出足够的细胞，可作为成功生长培养的接种物。数据支持将W / O乳液用作藻类培养的种子技术。成功的细胞存储技术必须在变化的温度下长时间保持细胞活力和物理稳定性。除了了解物理和生物稳定性如何受到储存温度的影响外，重要的是确定乳液在长时间暴露于致死温度下是否对细胞提供保护。在油相中用不同的增稠剂（二氧化硅纳米颗粒和Bentone 38）配制含有Sorokiniana小球藻和Minutissima小球藻的乳液，并将高温下的细胞活力与未配制的细胞悬液进行比较。乳剂提供了Sorokiniana小球藻的保护，使其在24小时后暴露于42°C。含有二氧化硅纳米粒子的乳液在72小时后显示出延长的温度保护。在46.5℃下，与用二氧化硅配制的乳液相比，用Bentone 38配制的细胞悬浮液和乳液中的细胞失活更大。与含有二氧化硅纳米颗粒和Bentone 38的乳液相比，含有小球藻的细胞悬浮液在38°C和42°C时具有更快的失活​​常数。在38°C时，含有二氧化硅纳米颗粒的乳液中的细胞死亡率较低，并且不易受热的影响。时间。暴露8小时后在42°C，用二氧化硅纳米粒子配制的乳液显示出显着的细胞灭活保护作用。 （摘要由UMI缩短。）。

著录项

  • 作者

    Fernandez Anderson, Lorena Elizabeth.;

  • 作者单位

    University of California, Davis.;

  • 授予单位 University of California, Davis.;
  • 学科 Chemistry Physical.;Engineering Environmental.;Engineering Agricultural.
  • 学位 Ph.D.
  • 年度 2013
  • 页码 176 p.
  • 总页数 176
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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