Antibacterial Activity of Ulva Lactuca Against Important Aquaculture Bacterial Strains

  • Sofia PAPPOU University of Aegean, University Hill, Lesvos Island, 81100 Mytilene
  • Michail Angelos VALSAMIDIS University of Aegean, University Hill, Lesvos Island, 81100 Mytilene
  • John BATJAKAS University of Aegean, University Hill, Lesvos Island, 81100 Mytilene
  • Vasileios BAKOPOULOS University of Aegean, University Hill, Lesvos Island, 81100 Mytilene
Keywords: algal extracts, antibacterial activity, aquaculture, fishfeed additives

Abstract

Efforts are made to produce functional aquaculture diets capable of promoting fish growth and health while being sustainable at social, economic and environmental levels. One of the emerging threats in aquaculture has become the antibiotic resistance phenomena due to antimicrobial drugs. Therefore, functional feed additives of marine origin have been introduced globally as an alternative to fish antibiotics. Towards the selection of natural and sustainable resources of bioactive compounds, seaweed has been proven to be a source of valuable substances showing antibacterial activity. Aim of this study is to evaluate the inhibition of bacterial growth caused by an ethanolic extract of the macroalgae Ulva lactuca against important aquaculture bacterial strains. Vibrio anguillarum O1, Photobacterium damselae sub. piscicida and Tenacibaculum maritimum, were incubated for 48 hours in sterile Brain Heart Infusion Broth and tested for resistance to the extract using broth cultures. The algal extract successfully inhibited the growth of all strains. The optimum inhibition was achieved for VAO1 and PHDP by the undiluted and 1:1 diluted extract, while for TMAR, by the 1:3 dilution as well. The antibacterial activity that the extract provided is considered to be the result of the containing bioactive compounds of the algal strain, such as polysaccharides, carotenoids and phenolic compounds.

Author Biographies

Sofia PAPPOU, University of Aegean, University Hill, Lesvos Island, 81100 Mytilene

Department of Marine sciences

Michail Angelos VALSAMIDIS, University of Aegean, University Hill, Lesvos Island, 81100 Mytilene

Department of Marine sciences

John BATJAKAS, University of Aegean, University Hill, Lesvos Island, 81100 Mytilene

Department of Marine sciences

Vasileios BAKOPOULOS, University of Aegean, University Hill, Lesvos Island, 81100 Mytilene

Department of Marine sciences

Published
2023-11-15