Green algae,also known as Chlorophyta,comprise one of the
most varied and highly specialized groups of plants .Marine organisms are rich sources of structurally novel and biologically active metabolites(Ely etal.,2004). Inparticular,extracts of
marinealgae have been reported to exhibit antibacterial activity
(Mahasneh etal.,1995; Sachithananthan andSivapalan,1975;
Siddhanta etal.,1997). Moreover, Spirulina and Chlorella have
been extensively studied because of their importance as human foods and their in vitro and/or in vivo antioxidant potential
(Dillon andPhan,1993).