Photosynthetic microorganisms valorization process for integral use of biomass, characterised in that it includes the following stages: - An initial stage whereby microalgal biomass is placed in an agitated tank in which cellulolytic enzymes are used to produce liquefaction of the sugars, rupturing the cell walls and releasing the soluble carbohydrates, with the rest of the components remaining in the residual biomass; the mixture obtained is separated using a filtering and/or centrifuging process, giving rise to a clarified solution rich in carbohydrates and a concentrate containing the residual biomass. - A stage consisting of production of bioethanol and other derived products such as lactic acid from the aforementioned solution by means of saccharification of the carbohydrates, followed by alcoholic fermentation with yeast to transform the monosaccharides into bioethanol with a high yield fermentation process. - A stage consisting of production from the residual biomass of peptide and amino acid concentrates using proteolytic enzymes which break down and solubilize the proteins in an enzymatic hydrolysis process, transforming the proteins into peptides and amino acids with a lower molecular weight that can be used for foodstuffs or as high-value agricultural fertilizers. The reaction mixture obtained is then separated using a filtering and/or centrifuging process, giving rise to a solution rich in peptides and amino acids and a concentrate containing the residual biomass. - A stage consisting of biodiesel production from the aforementioned concentrate, involving transesterification of the fatty acids in the biomass with sulphuric acid as a catalyser and methanol as a reagent, to obtain the respective methyl esters making it up. When the reaction is complete, the biodiesel is extracted from the reaction mixture using hexane, which is then evaporated to obtain the biodiesel. - A stage consisting of biogas production, whereby the residual biomass resulting from the previous stage is subjected to an anaerobic digestion process by the action of methanogenic bacteria, in order to produce biogas from the resulting methanol-free and hexane-free reaction mixture, whereby the residual carbonaceous matter contained in the same is transformed into methane, hydrogen and CO 2. - An initial stage whereby microalgal biomass is placed in an agitated tank in which cellulolytic enzymes are used to produce liquefaction of the sugars, rupturing the cell walls and releasing the soluble carbohydrates, with the rest of the components remaining in the residual biomass; the mixture obtained is separated using a filtering and/or centrifuging process, giving rise to a clarified solution rich in carbohydrates and a concentrate containing the residual biomass. - A stage consisting of production of bioethanol and other derived products such as lactic acid from the aforementioned solution by means of saccharification of the carbohydrates, followed by alcoholic fermentation with yeast to transform the monosaccharides into bioethanol with a high yield fermentation process. - A stage consisting of production from the residual biomass of peptide and amino acid concentrates using proteolytic enzymes which break down and solubilize the proteins in an enzymatic hydrolysis process, transforming the proteins into peptides and amino acids with a lower molecular weight that can be used for foodstuffs or as high-value agricultural fertilizers. The reaction mixture obtained is then separated using a filtering and/or centrifuging process, giving rise to a solution rich in peptides and amino acids and a concentrate containing the residual biomass. - A stage consisting of biodiesel production from the aforementioned concentrate, involving transesterification of the fatty acids in the biomass with sulphuric acid as a catalyser and methanol as a reagent, to obtain the respective methyl esters making it up. When the reaction is complete, the biodiesel is extracted from the reaction mixture using hexane, which is then evaporated to obtain the biodiesel. - A stage consisting of biogas production, whereby the residual biomass resulting from the previous stage is subjected to an anaerobic digestion process by the action of methanogenic bacteria, in order to produce biogas from the resulting methanol-free and hexane-free reaction mixture, whereby the residual carbonaceous matter contained in the same is transformed into methane, hydrogen and CO 2.