Abstract :
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.
Keyword :
Chlorella vulgaris, Biodiesel, Streptomyces, lipase, protein, biomass