Phytoplankton production systems in a shellfish hatchery: variations of the bacterial load and diversity of vibrios

• Published in: Journal of applied microbiology Vol. 118; no. 6; pp. 1264 - 1275
• Main Authors: Dubert, J, Fernández‐Pardo, A, Nóvoa, S, Barja, J.L, Prado, S
• Format: Journal Article
• Language: English
• Published: England Published for the Society for Applied Bacteriology by Blackwell Science 01-06-2015; Oxford University Press
• Subjects: Algae; Animals; Bacteria; Bacterial Load; Biodiversity; Bivalvia; Bivalvia - microbiology; breeding stock; continuous culture system; disease outbreaks; Fish hatcheries; Food Contamination - analysis; hatcheries; intermediate scale culture; larvae; microalgae; microbial load; Microbiology; microbiota; Molecular Sequence Data; mollusc culture; monitoring; pathogens; phytoplankton; Phytoplankton - classification; Phytoplankton - genetics; Phytoplankton - growth & development; Phytoplankton - isolation & purification; phytoplankton production systems; Plankton; production technology; quantitative analysis; risk; Shellfish; Shellfish - microbiology; shellfish hatchery; Vibrio; Vibrio - classification; Vibrio - genetics; Vibrio - growth & development; Vibrio - isolation & purification; microbiota; shellfish hatchery; bacteria; intermediate scale culture; phytoplankton production systems; continuous culture system; Vibrio
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1111/jam.12787

AIMS: Outbreaks of disease caused by some Vibrio species represent the main production bottleneck in shellfish hatcheries. Although the phytoplankton used as food is one of the main sources of bacteria, studies of the associated bacterial populations, specifically vibrios, are scarce. The aim of the study was the microbiological monitoring of the microalgae as the first step in assessing the risk disease for bivalve cultures. METHODS AND RESULTS: Two phytoplankton production systems were sampled weekly throughout 1‐year period in a bivalve hatchery. Quantitative analysis revealed high levels of marine heterotrophic bacteria in both systems throughout the study. Presumptive vibrios were detected occasionally and at low concentrations. In most of the cases, they belonged to the Splendidus and Harveyi clades. CONCLUSIONS: The early detection of vibrios in the microalgae may be the key for a successful bivalve culture. Their abundance and diversity were affected by factors related to the hatchery environment. SIGNIFICANCE AND IMPACT OF THE STUDY: This work represents the first long study where the presence of vibrios was evaluated rigorously in phytoplankton production systems and provides a suitable microbiological protocol to control and guarantee the quality of the algal cultures to avoid the risk of transferring potential pathogens to shellfish larvae and/or broodstock.