Phytochemical Analysis and Antibacterial Activity of Aphanothece Pallida (kütz.) Rabengh. Collected from Diara Pond, Hooghly, West Bengal

The present paper was dealt with the qualitative and quantitative screening of some phytoconstituents of a blue green alga Aphanothece pallida (Kütz.) Rabengh. and in vitro antibacterial activity study of four various organic solvent extracts with different polarities (benzene, chloroform, acetone and methanol) of the same alga, collected from a pond of Diara of Hooghly district, West Bengal. The tested alga showed positive results of having active organic compounds and specific inhibitory effects on three gram positive and one gram negative tested pathogenic bacterial strains. The qualitative screening results revealed that Aphanothece pallida contained steroid, terpenoid, phenol, flavonoid and flavonol in all the solvent extracts studied. Quantitative estimation of chloroform and benzene extracts showed the presence of higher and lower phenolic contents 5.38±0.14 mg/g and 2.99±023 mg/g respectively. Acetone extract showed the highest flavonoid content 10.86±0.24 mg/g whereas, methanol extract possessed high amount of flavonol content 27.06±0.47 mg/g and low amount of flavonoid content as 5.88±0.20 mg/g. Antibacterial activity revealed that Bacillus subtilis and Staphylococcus aureus were more susceptible whereas Micrococcus luteus and Escherichia coli were comparatively less susceptible against all the four solvent extracts.