Method for extracting grease from oleaginous microorganisms

Abstract

The invention relates to the field of microbial engineering, and discloses a method for extracting grease from oleaginous microorganisms. The method comprises the following steps of: mixing cellulose and protease to form mixed enzyme, hydrolyzing wet thalli of the oleaginous microorganisms, centrifuging, leaching an obtained precipitate, and desolventizing to obtain the grease, wherein the mass ratio of the cellulose to the protease is 1:(0.25-4); and the protease is neutral protease or alkali protease. In addition, the method also comprises the following steps of: hydrolyzing wet thalli of Rhodotorula glutinis by using the protease, centrifuging, leaching an obtained precipitate, and desolventizing to obtain the grease, wherein the protease is the neutral protease or the alkali protease;and the mass ratio of the protease and the thalli of the oleaginous microorganisms is (0.01-0.15):(1-10). By the method, the wet thalli are directly adopted for extraction, so that energy consumptionis reduced, reaction conditions are mild, the reaction has high specificity, the higher yield of the grease can be obtained with a smaller amount of enzyme, and extraction efficiency is higher; and the method is favorable for industrial production.

Description

technical field [0001] The invention relates to the field of microbial engineering, in particular to a method for extracting oil from oil-producing microorganisms. Background technique [0002] Microbial oil, also known as single-cell oil, is oil produced by microorganisms such as yeast, mold, bacteria, and algae under certain conditions using carbohydrates, hydrocarbons, and ordinary oils as carbon and nitrogen sources, supplemented by inorganic salts, and organic oils. Lipids of commercial value. Under suitable conditions, the oil produced and stored by some microorganisms accounts for more than 20% of its total biomass, and the strains with such phenotypes are called oleaginous microorganisms. [0003] At present, the oleaginous microorganisms that have been studied more are yeast, algae and molds. The cells of oleaginous yeast contain a large amount of triglycerides, and their fatty acid composition is similar to that of edible oils from plants; oleaginous algae have hi...

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Problems solved by technology

Freezing and thawing is a sudden change in temperature. The cells swell and break while forming ice particles and increasing the salt concentration of the remaining cytosol, so as to achieve the purpose of breaking the cells. However, in the process of repeated freezing and thawing, it takes a long time , some microbial cells have produced autolysis to reduce the oil content, and the oil yield is poor; the acid-heat method mainly uses the effect of hydrochloric acid on the sugar and protein in the cells to loosen the structure of the cells, and then undergoes boiling water and freezing treatment. The cell can achieve the effect of crushing, and the oil yield rate of the crushed cell is high, but it will produce a large amount of acid wastewater, and the pollution is more serious; the cell crushing by ultrasonic method is to use the unique mechanical vibration generated by the ultrasonic wave, which is the change of the cell structure and promotes cell fragmentation. , the oil yield is slightly lower than that of the acid-heat method, and heat is generated under the action of ultrasonic waves for a long time, which causes some oil to undergo a decomposition reaction, which is not conducive to the extraction of oil. In addition, the ultrasonic method has a small processing capacity and cannot be expanded for reproduction; relatively Compared with the above methods, the enzymatic hydrolysis method has many advantages. The existing enzymatic hydrolysis methods generally use cellulase, lysozyme, helicase, etc. for hydrolysis. Since the cell crushing is carried out by enzymatic hydrolysis, the crushing conditions are mild and the energy consumption is low. Low and large processing capacity, but the extraction efficiency of the enzymatic hydrolysis method is not high, which affects the application of the enzymatic hydrolysis method to a certain extent

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