NOVELTY - Fermenting microbial grease by inulin, comprises e.g. (a) taking 7 parts of inulin powder with the purity of 90%, dissolving the powder into 93 parts of distilled water, adding the sterilized inulase, adding 60-100 U inulase per gram of inulin powder to the mixture, and hydrolyzing at 60 degrees C for 8-12 hours to obtain the inulin hydrolyzate, and (b) fermenting cultivated grease microbe comprising (b1) selecting two strains of fresh Trichosporon cutaneum bacterium activated in the sterile condition and inoculating the stains to the sterile bean sprout juice culture medium.    USE - The method is useful for fermenting microbial grease by inulin (claimed), which is useful in bio-diesel.    ADVANTAGE - The method is capable of economically fermenting microbial grease by inulin in an environmental friendly manner.    DETAILED DESCRIPTION - Fermenting microbial grease by inulin, comprises (a) taking 7 parts of inulin powder with the purity of 90%, dissolving the powder into 93 parts of distilled water, adding the sterilized inulase, adding 60-100 U inulase per gram of inulin powder to the mixture, and hydrolyzing at 60 degrees C for 8-12 hours to obtain the inulin hydrolyzate, (b) fermentation cultivation of grease microbe comprising (b1) selecting two strains of fresh Trichosporon cutaneum bacterium activated in the sterile condition and inoculating the stains to the sterile bean sprout juice culture medium, cultivating the medium in the shaker at 30 degrees C for 72 hours with the rotating speed of 150 revolution per minute (rpm) to obtain the fermented seed liquid, where producing a bean sprout juice culture medium comprises weighing 100 g of fresh bean sprout, putting the bean sprout into the flask, adding 1000 ml of water and boiling for 30 minutes, filtering the bean sprout using the gauze, and supplementing the residual liquid to 1000 ml by distilled water, adding 50 g of sugar, heating and melting the sugar to obtain the culture medium and sterilized at 121 degrees C for 20 minutes, (b2) adding 5 g of yeast extract, 2 g of peptone, 1 g of monopotassium phosphate and 0.5 g of magnesium sulfate heptahydrate to the per liter of inulin hydrolyzate as the nitrogen source and the inorganic salt, mixing and dissolving the materials, and adjusting the pH value using 0.2 mol/l of the sodium hydroxide to obtain the inulin hydrolyzate fermentation culture medium, and sterilizing the inulin hydrolyzate fermentation culture medium at 115 degrees C for 30 minutes, inoculating the sterilized inulin hydrolyzate fermentation culture medium into the fermentation seed liquid, where the volume of the inoculated fermentation seed liquid is 10% of inulin hydrolyzate after adding the nitrogen source and the inorganic salt, performing the cultivation in the constant-temperature shaker cultivation box at 30 degrees C for 72 hours with the speed of 180 rpm, after the end of the fermentation, and centrifuging the product at 4500 rpm for 10 minutes to obtain the microbial grease thallus, and (c) drying the grease biological thallus, extracting dried grease in the grease microbial thallus cell using the organic solvent chloroform-methanol method including adding 10 ml of hydrochloric acid of 4 mol/l per each gram of thallus and uniformly mixing the materials in an oscillating way, placing the mixture at 25 degrees C for 30-60 minutes, and heating the mixture in the boiling water bath at 100 degrees C for 3 minutes, and immediately cooling the mixture at 20 degrees C for 30 minutes, after taking the mixture, adding 2 times of chloroform-methanol extraction liquid by volume and fully oscillating the materials for 2 minutes, and adding 1 ml of chloroform per gram of thallus and mixing the materials uniformly in an oscillating way, after adding 1.5 ml of distilled water per gram of thallus and mixing the materials uniformly in an oscillating way, centrifuging the mixture at 4000 rpm for 15-25 minutes after uniformly mixing, and adding the same volume of 0.1 mass% of sodium chloride solution into the separated chloroform layer, and centrifuging the mixture at 4000-5000 rpm for 15-25 minutes and then placing at 25 degrees C for 36 hours, volatilizing, and removing the chloroform to obtain the microbial biological grease, where the volume ratio of the chloroform to the methanol in the chloroform-methanol extraction liquid is 1:2.