*8.3.2 Botryllus schlosseri*

A specific bacterial species associated with *Botryllus schlosseri* was isolated and tested for their specific biological activities. *Bortyllus schlosseri* is a colonial ascidian composed of several tiny individual zooids enveloped by single tunic. Its an native to Europe. MTT analysis performed confirmed the cytotoxic activity of the crude extracts of the isolated bacterial strains. Extracts showed that, about 90% of the extracts showed cytotoxicity towards human heptatocellular carcinoma Bcl 7402 cells and human cervical carcinoma cell lines HeLa. Antimicrobial activity of the ascidian *Botryllus schlosseri* associated bacterial extracts showed that, it inhibits Gram-negative bacteria, Gram-positive bacteria, human pathogenic fungi and aquatic animal pathogenic bacteria. Thus, it exhibited higher incidence of resistance towards Gram-positive bacteria such as *Bacillus subtilis* and *Staphylococcus aureus* than Gram-negative bacteria [69].
