Preparation Of Polystyrene Fiber Membranes By Electrospinning As Carriers For Probiotics Biofilm

Probiotics are kinds of living bacterium that are beneficial to the health of the host when ingesting appropriate amount.Biofilm is highly organized microbial population that is tightly wrapped by extracellular matrix.The biofilm form of probiotics not only improves its tolerance to adverse environments,but also enhances the fermentation ability of probiotics.Electrospun fibers are with the advantages of high porosity and high specific surface area,and the three-dimensional structure of them are similar to the natural extracellular matrix.And the electrospun fiber membranes can mimic the structure of the extracellular matrix and have the functions of separating tissue,supporting cells,and providing cell anchoring points.Thus they are suitable carriers for cell immobilization.In this paper,the electrospinning technology is used to prepare polystyrene fibers with different diameters by adjusting the electrospinning parameters,which are used as carrier materials for probiotic biofilm formation.Scanning electron microscopy and plate count are used to analyze the ability of Lactobacillus plantarum,Lactobacillus paracasei and Saccharomyces boulardii to form biofilm on electrospun nanofiber membranes with different fiber sizes.The research results are as follows:1.When the concentration of the spinning solution increases,continuous fibers are easier to form,and the fiber morphology gradually changes from a spindle-like shape to a wire-like shape.Besides,a uniform diameter distribution and increased average diameters of fibers are obtained with the increasing concentration of the spinning solution.As the flow rate increases,the fiber diameter increases,especially for the solution with high concentration.When the voltage increases,the spinning process of the low-concentration spinning solution can be smoothly performed and the fiber diameters decrease for the high-concentration spinning solution.The tip-to-collector distance has little effect on the fiber diameter of low concentration spinning solution.Polystyrene fibers which have average fiber diameter of 0.4 ?m to 4.0?m were obtained by electrospinning.2.Electrospun polystyrene fiber membranes have high porosity and large specific surface area,which is suitable for the adhesion and growth of Lactobacillus plantarum,Lactobacillus paracasei and Saccharomyces boulardii as the carrier materials.All the three probiotics can form biofilms on the electrospun polystyrene fiber membranes.The time and the morphology of biofilms are related to the size of the microorganism.The smaller the average fiber diameter,the shorter time required for biofilm formation and the denser the biofilm is formed on surface.When the fiber diameter is on the large micron scale,the lactic acid bacteria forming biofilm needs more time,and the biofilm is thinner,but Saccharomyces boulardii can still form biofilm on large-sized fibers.3.According to the results of plate count,we find that small Lactobacillus plantarum is suitable for forming biofilm on PSFM-1,and Lactobacillus paracasei is suitable on PSFM-2 with a slightly larger size,and Saccharomyces boulardii is more suitable on PSFM-4 with larger size.The maximum viable cells on the biofilm are 9.30×108 CFU/cm2(Lactobacillus plantarum),1.57×109 CFU/cm2(Lactobacillus paracasei),7.18×107 CFU/cm2(Saccharomyces boulardii).As microorganisms become larger,the size of the fibers suitable for their growth become larger.When the average fiber size matches the size of the microorganisms,the fiber membranes provide the best support for microorganisms to adhere and colony,and constitute a frame scaffold for biofilm formation.