Method for extracting ribonucleic acid and cell wall polysaccharides in single cell protein by using one-step method

Abstract

The invention discloses a method for extracting ribonucleic acid (RNA) and cell wall polysaccharides, in particular to a single cell protein prepared by using brewers' yeast. The method comprises the steps of: adding water with 10-30 percent of dry weight of the single cell protein and then fully mixing, freezing at a low speed, placing into an ultrasonic assisting water bath, repeatedly thawing and breaking cell walls; adding sodium chloride with weight ratio of 5-18 percent, rapidly cooling, and eccentrically separating to obtain supernate and cell wall polysaccharides precipitates; and washing the precipitates by using water and then drying to obtain dry products of the cell wall polysaccharides. The protein is precipitated at an isoelectric point PI4.2 in the supernate, the RNA is participated at an isoelectric point PI2.5, and the dry product of the RNA is obtained by the supernate. Because a mixture of amino acid is separated by adopting methods of repeatedly freezing and thawing for breaking the single cell protein and regulating the isoelectric points, the invention has the characteristics of high separation and extraction efficiency, high purity and simple and convenient method.

Description

technical field

[0001] The invention relates to a method for extracting ribonucleic acid and cell wall polysaccharide in single-cell protein. Background technique

[0002] Single-cell protein is also called microbial protein, which is an artificially cultivated microbial cell. Single-cell protein is not a pure protein, but a cytoplasmic mass composed of a mixture of proteins, fats, carbohydrates, nucleic acids, nitrogenous compounds, vitamins, and inorganic compounds. It is rich in nutrients, especially the single-cell protein produced by fermentation of brewer's yeast, which has a high content of ribonucleic acid and cell wall polysaccharides, and the brewer's yeast used in this method is a recognized non-toxic and harmless widely used in medicine , industrial and food fields with higher biological safety strains. Most of the previous extraction processes were limited to the extraction of one product, and a large number of other substances with high added value were disca...