Preliminary phycochemical analysis and in vitro antibacterial screening of green micro algae, Desmococcus Olivaceous, Chlorococcum humicola and Chlorella vulgaris

Antibacterial activity of the Acetone, methanolic, ethanolic and DMSO extract of dried green microalgae Desmococcus olivaceous, chlorococcum humicola and chlorella vulgaris was assayed against five gram-ve (Klebsiella pneumoniae, Pseudomonas, Vibriocholerae, Streptococccus pyrogenes and Escherichia coli) and one gram +ve (Staphylococcus aureus) bacteria under culture conditions, using the agar disc diffusion technique. Incubation of the Mullar-Hinton agar plates for 24hrs. at 30°C, supplemented with the six test bacteria along with 50ml of acetone, methanolic, ethanolic and DMSO (Dimethyl sulphoxide) extract revealed inhibitory effect. The highest inhibition zone (25 mm& 21 mm ) was observed in acetone extract of Chlorococcum sp against gram +ve bacteria (Staphylococcus aureus) & gram -ve bacteria ( Escherichia coli). Preliminary phycochemical analysis was also performed on the dried algal sample by employing chemical methods and thin layer chromatography technique to assay the bioactive compounds which revealed the presence of seven principle bioactive compounds viz., phenolic, tannin, flavanoids, saponins, terpenes, carbohydrates & cardiac glycosides.