A Study on Probiotic Bacteria Isolated from Common Dentex (Dentex dentex) Larvae and their antagonistic effect on Photobacterium damselae subsp damselae

Abstract

Bacterial species that can be considered as probiotic are gradually gaining attention and contributing to the success of aquaculture. The aim of this study was to determine the indigenous dominant probiotic bacterial species of common dentex (Dentex dentex) larvae and their effectiveness against the putative fish pathogen Photobacterium damselae subsp. damselae at different feeding stages. In 2009-2010 samples of larvae and tank water were collected at 5 different occasions. After inoculations of samples, bacterial isolates were identified with standard biochemical methods. The antagonistic effects of the identified probiotic bacteria against P. damselae subsp. damselae isolated from different mariculture fishes were determined by using disc diffusion method. Bacillus cereus, B. macquariensis, and other Bacillus sp., Micrococcus luteus, Flavobacterium flevense and Flavobacterium sp. were identified as candidate probiotic species and their antagonistic effect against different P. damselae isolates was identified. The results of this study showed that B. cereus and M. luteus are more effective against Photobacterium damselae subsp. damselae. As a result, the identification of the candidate probiotic species and the widespread use of probiotics may improve the success of common dentex culture in the future.