The Establishment Of Marine Microorganisms Microencapsulation Technology

We have obtained monodisperse alginate microcapsules ranged from 45–175μm using a new microfluidic approach ,which has the added advantages of being low cost and a simple solidify process. The preparation condition for producing uniform-sized microspheres was optimized. The ambient liquid flow rate, Sodium alginate flow rate and viscosity of the alginate solution 3~5%(w/v) effects on diamenter were studied. We have demonstrated that the size of alginate microcapsules increased with the increasingof the sodium alginate flow rate, whereas it decreased with the increasing of the ambient liquid flow rate . In addition, results obtained show that the morphology of alginate micrspheres can be easily controlled by the concentration and flow rate of coagulant(glycerol and calcium chloride ).The characterization of the monodisperse droplets was investigated and we also proved that after culturing the individual marine microorganisms within microdrops, organisms remained alive and the bacterial growth and microcolony formation in microdrops were analyzed by fluorescence microscopy, and quantitatively measured the fluorescence intensity of microcolonies using flow cytometry.Among the microchannel emulsification methods applied for preparing natural polymeric microspheres, produce and solidify process were separated and the morphology of micrspheres highly effected by coagulant[1-3].In the present study, we explored a novel attempt to entrap the marine bacterial into the alginate microbeads. This new method based on a coflowing liquid stream device [1], however, it made the process of solidify the microstructure of alginate microcapsules completed at the same time of production. For that reason, the new micro- encapsulation device has produced monodisperse and spherical alginate microspheres more easily.It was found that, when the flow rate of less than 60mL / h, the dispersed phase flow rate is less than 0.2mL / h and sodium alginate concentration of less than 2% (w / v), which were unable to obtain monodisperse alginate microspheres . The proportion of the calcium chloride (2%w/v) and glycerol was confirmed as 2:1.We can obtain the can the stable and spherical microspheres. The microspheres of the alginate have good mechanical stability, with the increasing of storage time, the microspheres remaining the spherical and smooth surface; we investigated the protein as a big molecule diffused in the 5% (w/v)alginate microspheres. The changed of protein concentration suggested that the structural of the microsphere have a good permeability to allow the permeation of substances.The microspheres exhibited different diameters in solution of different pH. When the pH was greater than 5, they remained in a original state. In contrast, the microspheres appeared compact state in acid media with pH less than 4.This study prepared monodisperse alginate microspheres using for culturing marine organisms Vibrio harveyi SF-1.The growth characteristics of encapsulated bacteria was evaluated visually by scanning electron microscopy, fluorescence microscopy, and quantitatively by measuring the fluorescence intensity of microcolonies using flow cytometry. The marine bacterial enclosed in the microsphere have a high viability.