Diversity of Bacterioplankton and Bacteriobenthos from the Veracruz Reef System, Southwestern Gulf of Mexico.

Yuri B Okolodkov,Andrea M García-Casillas,Allan D Cembella,Citlali Rodríguez-Gómez,Lorena María Durán-Riveroll,Rosa María Oliart-Ros

doi:10.3390/microorganisms9030619

Abstract

Bacterial diversity was explored among field samples and cultured isolates from coral reefs within the Veracruz Reef System. Bacterioplankton and bacteriobenthos were characterized by pyrosequencing 16S rRNA genes. Identified sequences belonged to the kingdom Bacteria and classified into 33 phyla. Proteobacteria (likely SAR11 clade) dominated in collective field samples, whereas Firmicutes were the most abundant taxa among cultured isolates. Bioinformatic sorting of sequences to family level revealed 223 bacterial families. Pseudomonadaceae, Exiguobacteraceae and Bacillaceae were dominant among cultured isolates. Vibrionaceae, Alteromonadaceae, and Flavobacteriaceae dominated in reef-associated sediments, whereas Rickettsiaceae and Synechoccaceae were more highly represented in the water column. Bacterial communities from sediments were more diverse than from the water column. This study reveals cryptic bacterial diversity among microenvironmental components of marine microbial reef communities subject to differential influence of anthropogenic stressors. Such investigations are critical for constructing scenarios of environmentally induced shifts in bacterial biodiversity and species composition.

Highlights

Coral reefs are among the best known examples of ecosystems subject to rapid loss of biodiversity within the last several decades [1]
This study focused on two coral reefs of the Veracruz Reef System (VRS) along the Gulf of Mexico coast: Isla Verde Reef (IVR) (19◦ 110 54.100 N, 96◦ 040 0.700 W) located offshore from Veracruz, and
Many common sequences of 16S rRNA were found between cultured isolates and those recovered directly from environmental samples from the VRS, among the Firmicutes and Proteobacteria

Summary

Introduction

Coral reefs are among the best known examples of ecosystems subject to rapid loss of biodiversity within the last several decades [1]. Microbial populations inhabiting coral reef systems differ widely in taxonomic composition, and the microalgal component and particulate organic matter in surrounding waters are highly diverse [2,3]. This diversity has a direct but differential influence on host and community health and metabolic processes—the holobiont concept. One of the main goals in biodiversity research on microbes has been to understand their functional role and impact within and among ecosystems at local, regional, and global scales Both prokaryotic and eukaryotic microbes play a critical role in primary production and in biogeochemical cycles in the ocean [4], including coral reef ecosystems

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