TECHNOLOGY FOCUS - BIOLOGY - Preferred Components: Extracting oil from Microcystis involves culturing microalgae in presence of light. Frustule of microalgae is collected and then oil is extracted from the collected product. The microalgae is selected from Chlorella pyrenoidosa, Chlorella vulgaris, Chlorella ellipsoidea, Chlorella emersonii, Chlorella sorokiniana, Chlorella saccharophila, Chlorella regularis, Chlorella minutissima, Chlorella protothecoides, Chlorella zofingiensis, Branchiomonas submarina, Chlamydobonas reinhardtii, Chlamydobonas acidophila, Haematococcus pluvialis, Haematococcus lacustris, Scenedesmus obliquus, Spongiococcum exetriccium, Tetraselmis suecica, Tetraselmis ccuii, Tetraselmis tetrathele, Tetraselmis verrucosa, Micractinium pusillum, Cylindrotheca fusiformis, Nitzschia laevis, Nitzschia alba, Nitzschia fonticola, Navicula incerta, Navicula pelliculosa, Anabaena variabilis, Poterioochromonas malhamensis, Amphidinium carterae, Crypthecodinium cohnii, Euglena gricilis and Galdieria sulfuraria. The microalgae are cultured in a medium containing organic carbon source, inorganic salt, trace element, water and nitrogen source. The culture medium contains 5-15 g/L of potassium nitrate, 10-60 g/L of glucose, 0.3-0.9 g/L of potassium dihydrogen phosphate, 1.0-10.0 g/L of disodium hydrogen phosphate dodecahydrate, 0.2-1.0 g/L of mangnesium sulfate heptahydrate, 0.05-0.3 g/L of calcium chloride, 0.01-0.05 g/L of ferrous sulfate heptahydrate, 0.5-4 ml of trace element, where the trace element is composed of 5-15 g/L of boric acid, 5.0-10.0 g/L of zinc sulfate heptahydrate, 1.0-2.0 g/L of manganese chloride monohydrate, 0.5-1.5 g/L of ammonium molybdate hydrate, 1.0-2.0 g/.L of copper sulfate pentahydrate, and 0.1-0.9 g/L of cobalt nitrate hexahydrate and water. The culture medium is composed of the following components according to proportion by weight: 10-60 g/L of glucose, 2-8 g/L of urine, 1-2 g/L of potassium dihydrogen phosphate, 1.0-10.0 g/L of disodium hydrogen phosphate dodecahydrate, 1-2 g/L of mangnesium sulfate heptahydrate, 0.05-0.1 g/L of calcium chloride, 0.1-2.0 g/L of trisodium citrate, 0.5-1 mL of iron-EDTA solution, 1-5 ml of A5 solution, where the A5 solution is prepared from 2.5-4.0 g/L of boric acid, 1.0-2.0 g/L of mangnese chloride tetrahydrate, 0.1-0.6 g/L of zinc sulfate heptahydrate, 5-10 g/.L of copper sulfate pentahydrate, and 0.01-0.05 g/L of sodium molybdate, and water.