Ultrasonic Effect On Salting Out Of Bovine Serum Albumin

The application of ultrasonic wave in biotechnology is a relatively updated attentive study area. Mechanical mass transfer, heating effect and cavitation effect are physical mechanism. In biological technology area, ultrasound is used in enzyme engineering, fermentation engineering, cell engineering and biology therapy to tumour[3]. Salting-out is a classic method for separation, and Harnmarstein[4] was the first person who disparted bovine serum albumin from bovine serum by ammonia sulfate. The study and application on improving salting-out by ultrasound has not been reported.Protein is a kind of the most important organic compound that decides vital being and movement. It is a polymer of amino acid, that is, protein is "the necklace" stringed by amino acid. All amino acids at least contain two functional group, an amino group and a carboxylic group on α-carbon. To water-soluble protein, its aqueous solution is hydrophilic colloid. The reason of protein dissolving in water and forming stable colloid solution is due to its molecule conformation. There are hydrophilic groups on the protein surface, which are very easy hydrated and form a water layer, so they can dissolve into aqueous solution. In addition, if the pH value of the solution deviates isoelectric point, all molecules with same electric charge will more promote their dispersion capability. To sum up, the factor, that can destruct the hydrophilic effect or weaken the property of homogeneous repulsion, maybe reduces the solubility in water and makes them to precipitate down.There are many ultrasonic effects to protein salting-out relatively. One hand, there are many acoustic parameters, such as sound intensity, frequency, irradiation time etc. On the other hand, many protein system properties, for instance, density,viscosity and so on, can affect the result of ultrasound salting-out. The factors of sound intensity, irradiation time and centrifugation time to ultrasound acting on protein salting-out process were researched, meanwhile, compared with some results without ultrasound.In the study, ultrasonic mechanical effect was utilized. Ultrasound acts on the protein salting-out system. it promotes mass transfer and makes electrolyte ion to exchange the hydrated layer around the protein. So the protein loses its hydrated layer and electric charge on the surface. This kind protein is flocculated easily. So the extracting rate of protein is raised. Moreover, it makes the time to shorten 4.5 hours. Its economical prospect is wide.