NOVELTY - Mixotrophic cultivation of unicellular algae comprises e.g. harvesting a biomass of algae grown on mixotrophic medium and disrupting cells of unicellular algae; extracting algal lipids from micro-algae homogenate followed by recovery of solvents and separating lipids; performing transesterification of lipid, recovering raw glycerol; performing enzymatic hydrolysis of extracted biomass, separating by centrifugation of the algal material resistant to enzymatic hydrolysis; performing normalization of proteins and nucleic acids hydrolysates; and cultivating unicellular algae on a mineral medium.    USE - The process is useful for mixotrophic cultivation of unicellular algae; and the compounds resulting from the process, i.e. raw glycerol and hydrolysates of proteins and nucleic acids, are useful as source of carbon and nitrogen and phosphorus respectively for supplementation of autotrophic cultivation media.    ADVANTAGE - The mixotrophic process of micro-algae cultivation increases the yield of unicellular algae cultivation and recycling the nitrogen and phosphorus which are not used for biofuels production from proteins and nucleic acids of algal biomass.    DETAILED DESCRIPTION - Mixotrophic cultivation of unicellular algae comprises: harvesting a biomass of algae grown on mixotrophic medium and disrupting the cells of unicellular algae by high pressure homogenization; extracting algal lipids from micro-algae homogenate, using a solvent mixture, followed by recovery of solvents by distillation and separating lipids; performing transesterification of lipid, recovering raw glycerol, which is used, after correction to neutral pH with phosphoric acid, as the carbon source to supplement the micro-algae cultivation in mixotrophic medium, in a concentration of 2-5 g/l; performing enzymatic hydrolysis of extracted biomass with a mixture of hydrolases, phosphatases, nucleases and proteases, separating by centrifugation of the algal material resistant to enzymatic hydrolysis, which consists predominantly of recalcitrant (ligno)cellulose, and further processing the material to furans and levulinic acid, usable for bio-fuels production; performing normalization of proteins and nucleic acids hydrolysates by tangential ultrafiltration on a membrane with a cut-off molecular weight of 5 kDa, till 5% total nitrogen and 1.5% total phosphorus, and using as sources of nitrogen and phosphorus, to supplement micro-algae cultivation medium, in a concentration of 12.5 g/l; and cultivating unicellular algae on a mineral medium, supplemented with 16 g/l of sodium bicarbonate, 2-5 g/l of raw glycerol of concentration and 12.5 g/l of hydrolysates of proteins and nucleic acids, with 5% nitrogen and 1.5% phosphorus, on an aerated medium, with 1-10 l of a gaseous mixture, with 7% carbon dioxide per min per 100 I of medium, at a temperature of 28 degrees C and at illumination intensity of 250-1000 |iEm'2s'1, for 2-5 days, until a total concentration of 100 g/l of algal biomass is reached and harvesting algal biomass.