Antibacterial activity of green microalgae from stressed environmental conditions

Abstract

Bacterial resistance to antibiotics is a growing problem in worldwide health care. The discovery of new antibiotics has been less successful in recent years which have so far not proven to be as successful or safe as natural products. Photosynthetic fresh (non-saline) water green microalgae have, however, been recently shown to be a promising source of compounds with antibacterial activity. Extracts from microalgae from a variety of environments have inhibited growth of both gram-negative and gram-positive bacteria. By investigating untapped microalgal species that thrive in stressed environments, most likely through the production of protective secondary metabolites, there is a greater likelihood of discovering strains capable of producing bioactive compounds with antibacterial activity. In this study, microalgal species obtained from environments with low pH, high metal concentrations or municipal wastewater were tested against a variety of bacterial species. The results confirm that microalgae from stressed environments are a promising source of compounds exhibiting antibacterial activity.