RESUMO
The effect of the ethanolic extract of two algae Nostoc linkia and Chara sp has been tested on the growth of bacteria Escherichia coli, Pseudomonas aeruginosa which was isolated from contaminated water under laboratory conditions of 37°C and treatment period of 72 hour for two algae. The extract of Nostoc linkia showed high efficiency in reducing the bacterial number at concentration 1 mg/I at removal rates 98.9% for Escherichia coli and 94.6% for Pseudomonas aeruginosa. Algaeal extract of Chara sp at concentration 1 mg/I caused a reduction in bacterial numbers at a removal rate of 87% for Escherichia coil and 87% for Pseudomonas aeruginosa with a significant differences at concentrations of 0.75 and 1 mg/I for two algael extract. Total bacterial number is reduced by concentration of 1 mg/I for two algael extract Nostoc linkia and Chara sp. at removal rates 90.8% and 82.4 respectively after 24 hour of treatment