AUTHOR=Assis Juliana M. , Abreu Fernanda , Villela Helena M. D. , Barno Adam , Valle Rafael F. , Vieira Rayssa , Taveira Igor , Duarte Gustavo , Bourne David G. , Høj Lone , Peixoto Raquel S. 

TITLE=Delivering Beneficial Microorganisms for Corals: Rotifers as Carriers of Probiotic Bacteria

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.608506

DOI=10.3389/fmicb.2020.608506

ISSN=1664-302X

ABSTRACT=<p>The use of Beneficial Microorganisms for Corals (BMCs) to increase the resistance of corals to environmental stress has proven to be effective in laboratory trials. Because direct inoculation of BMCs in larger tanks or in the field can be challenging, a delivery mechanism is needed for efficient transmission of the BMC consortium. Packaged delivery mechanisms have been successfully used to transmit probiotics to other organisms, including humans, lobsters, and fish. Here, we tested a method for utilizing rotifers of the species <italic>Brachionus plicatilis</italic> for delivery of BMCs to corals of the species <italic>Pocillopora damicornis</italic>. Epifluorescence microscopy combined with a live/dead cell staining assay was used to evaluate the viability of the BMCs and monitor their <italic>in vivo</italic> uptake by the rotifers. The rotifers efficiently ingested BMCs, which accumulated in the digestive system and on the body surface after 10 min of interaction. Scanning electron microscopy confirmed the adherence of BMCs to the rotifer surfaces. BMC-enriched rotifers were actively ingested by <italic>P. damicornis</italic> corals, indicating that this is a promising technique for administering coral probiotics <italic>in situ</italic>. Studies to track the delivery of probiotics through carriers such as <italic>B. plicatilis</italic>, and the provision or establishment of beneficial traits in corals are the next proof-of-concept research priorities.</p>