Effect of the probiotic strainPhaeobacter gallaeciensisafter bacterial challenge on the complete larval development ofPecten maximus

Abstract

-The aim of this project was to evaluate the impact of probiotic (Phaeobacter gallaeciensis, X34 strain) treatment on the complete development (from veliger to metamorphosis) of Pecten maximus larvae in the context of a bacterial challenge and in conditions more representative of hatchery practices. To that effect, the present study was divided into two main steps. In the first, we used in vitro analyses (antibiograms and microplate assays) to validate the inhibition abilities of X34 on the growth of four Vibrio pathogen species. During the second step, we added pathogens (Vibrio pectenicida) into rearing tanks after two weeks of pre-treatment with the probiotic and then followed the larval development of Pecten maximus through the monitoring of survival rates, shell lengths and metamorphosis ability. Moreover, antioxidant (catalase and superoxide dismutase) and lipids peroxidation activities were also measured after bacterial challenge in order to evaluate the physiological response of larvae to pathogen exposition. Our results indicated an activation of the two selected antioxidant enzymes after bacterial challenge, but the increase was significantly lower in probiotic treated larvae. At the end of the experiment, the strain X34 treatment prevented a mass mortality event and showed a significant increase in the number of individuals reaching competence, when compared to untreated larvae.

The Alteration of Intestinal Microbiota Profile and Immune Response in Epinephelus coioides during Pathogen Infection

“…Researchers from Iran discovered that Maritalea is a radiation-resistant microorganism that acts as a remoistening agent to endure extreme dryness [ 65 ]. Phaeobacter spp., such as P. inhibens and P. gallaeciensis , have been used as probiotics against Vibrio pathogens in scallop and algae cultures [ 66 , 67 ]. Tropicibacter, Photobacterium, Donghicola and Shimia are genera that are abundant in marine organisms or seawater, and Photobacterium mainly live in symbiotic relationships with aquatic organisms [ 68 , 69 , 70 , 71 ].…”

Effects of hydrodynamic factors on Pecten maximus larval development

“…Vibrio load evolution was similarly assessed. Activities of several enzymes have been shown to be good indicators of the physiological status of bivalve larvae (Genard, Larouche, Nicolas, Miner, Beaudin & Tremblay ; Genard et al., ). Some of those associated with larval performances were accordingly used to estimate the effects of hydrodynamic factors on P. maximus larval condition and stress level.…”

Evaluación <i>in vitro</i> de bacterias marinas para potencial biocontrol en cultivo de moluscos bivalvos

“…Existen varios trabajos que exploran esta posibilidad específicamente en la inhibición de patógenos asociados a moluscos bivalvos, principalmente del género Vibrio sp. (Riquelme et al 1997, Long et al 2005, Leyton & Riquelme 2010, Leyton et al 2014, Genard et al 2014, De la Fuente et al 2015b, León et al 2016, Burks et al 2017, en este tipo de trabajos se considera importante que las bacterias marinas sean aisladas desde el hábitat en el cual tendrán que cumplir su función, para asegurar así su habilidad de crecer en las condiciones de uso y su inocuidad (Verschuere et al 2000). Con esa consideración, en este trabajo se aislaron bacterias marinas desde distintas matrices que tienen normalmente contacto con moluscos bivalvos en su ambiente natural en una zona costera de la provincia de Arauco, con el interés de aportar una herramienta para el desarrollo de acuicultura sostenible en esta zona.…”