Bacillus isolation--Bacterial cell isolation and collection process
At present, for the separation of bacterial cells from fermentation broth, traditional flocculation methods can be used, including organic solvent precipitation method, chemical precipitation method, and salting out method. The salting-out method needs to add a large amount of inorganic salts, the protein is volatile, the recovery rate is not high, and it has a great impact on the environment; the chemical precipitation method has poor versatility and needs to be decomposed and precipitated to recover the target product. , The method of separating and collecting bacterial cells under normal pressure, the equipment is simple to operate, the bacterial cell recovery rate is high, and there is no pollution, and it can also be sterilized by high-pressure steam at 121 degrees Celsius on demand.
Bacillus subtilis has two fermentation processes, namely solid fermentation process and liquid fermentation process. The number of bacteria produced by solid fermentation process is generally not high, and the level is about 5-50 billion. Liquid fermentation processes are different, where bacterial counts are usually high. Bacillus is a microorganism with very small molecular weight and particle size. Tianxing high-speed centrifuge can separate extremely fine microorganisms from fermentation broth without damaging the bacteria.
The basic principle is as follows:
The fermented suspension to be treated enters the drum from the hollow nozzle at the bottom of the feeding pipe under a certain pressure, and is distributed around the drum by the three-wing plates in the drum, and the suspension is accelerated in the drum to the same speed as the drum. , the density of the bacteria in the suspension is higher than that of the light liquid (water), so a larger centrifugal force is obtained, so the solids are concentrated in the outer layer of the drum, and the light liquid moves relative to the inner layer to form a light liquid layer, which passes through the upper ring. The overflow port is discharged, so as to achieve the purpose of liquid-solid separation. Solids are removed from the drum after shutdown.
The following is the separation site of Bacillus fermentation broth:
Comparasion before and after separation:
Solid (biomass) in bowl