AN IN VITRO STUDY ON ENZYMATIC TRANSESTERIFICATION OF MICROALGAL OIL FROM CHLORELLA VULGARIS FOR BIODIESEL SYNTHESIS USING IMMOBILIZED STEPTOMYCES Sp. LIPASE

Biodiesel is advised for use as an alternative fuel for conventional petroleum-based diesel because it is a renewable, with an environmentally friendly emission profile and is readily biodegradable. The effect of various growing conditions on biodiesel properties produced from Chlorella vulgaris has been investigated. The Chlorella vulgaris grown at different initial pH (4.0, 5.0, 6.0, 7.0 and 8.0) and Ammonia sources namely ammonium nitrate, ammonium sulphate, ammonium chlorite, ammonium tartrate and urea in laboratory condition. Chlorella vulgaris showed a gradual increase in cell number from pH 5.0 to 7.0. Maximum growth biomass of 6.6 mg/mL and Protein content 68.51 mg/mL was recorded at pH 7.0 on 7th day. Among the ammonia sources the maximum growth biomass of 7.8 mg/mL and maximum total protein content of 70 mg/mL was recorded in the presence of urea on 7th day. For lipase production, Streptomyces was inoculated in to the modified large production medium at different pH (3.0, 4.0, 5.0, 6.0, 7.0 and 8.0), carbon source (glucose, sucrose, lactose and maltose) and nitrogen sources (ammonium sulphate, ammonium nitrate yeast extract and peptone). The Streptomyces Sp. was able to release a maximum protein content of 67mg/ml at pH 8.0 after 66 h and lipase of 77 U/ml at pH 8.0 after 36 h. The maximum extra cellular protein content of 71 mg/ml in the existence of Sucrose at 36 h and maximum enzyme activity of 91 U/ml at 96 h compared to the rest of sugars. Whereas, the occurrence of nitrogen sources the yeast extract supported a maximum extracellular protein content of 74 mg/ml at 36 h and lipase production of 94U/ml at 36 h. Key words: Chlorella vulgaris, Biodiesel, Streptomyces, lipase, protein, biomass