Picoplankton Bloom in Global South? A High Fraction of Aerobic Anoxygenic Phototrophic Bacteria in Metagenomes from a Coastal Bay (Arraial do Cabo—Brazil)

Abstract

Marine habitats harbor a great diversity of microorganism from the three domains of life, only a small fraction of which can be cultivated. Metagenomic approaches are increasingly popular for addressing microbial diversity without culture, serving as sensitive and relatively unbiased methods for identifying and cataloging the diversity of nucleic acid sequences derived from organisms in environmental samples. Aerobic anoxygenic phototrophic bacteria (AAP) play important roles in carbon and energy cycling in aquatic systems. In oceans, those bacteria are widely distributed; however, their abundance and importance are still poorly understood. The aim of this study was to estimate abundance and diversity of AAPs in metagenomes from an upwelling affected coastal bay in Arraial do Cabo, Brazil, using in silico screening for the anoxygenic photosynthesis core genes. Metagenomes from the Global Ocean Sample Expedition (GOS) were screened for comparative purposes. AAPs were highly abundant in the free-living bacterial fraction from Arraial do Cabo: 23.88% of total bacterial cells, compared with 15% in the GOS dataset. Of the ten most AAP abundant samples from GOS, eight were collected close to the Equator where solar irradiation is high year-round. We were able to assign most retrieved sequences to phylo-groups, with a particularly high abundance of Roseobacter in Arraial do Cabo samples. The high abundance of AAP in this tropical bay may be related to the upwelling phenomenon and subsequent picoplankton bloom. These results suggest a link between upwelling and light abundance and demonstrate AAP even in oligotrophic tropical and subtropical environments. Longitudinal studies in the Arraial do Cabo region are warranted to understand the dynamics of AAP at different locations and seasons, and the ecological role of these unique bacteria for biogeochemical and energy cycling in the ocean.

Long-term seasonal and interannual variability of marine aerobic anoxygenic photoheterotrophic bacteria

“…A custom-made database was generated combining sequences from previous AAP studies [25,27,40,41], variants present in the Integrated Microbial Genomes system [42] and other pufM sequences from the GenBank database. Additionally, the predicted sequences from the BBMO metagenomes were included in this database.…”

Distribution and Classification of Serine β-Lactamases in Brazilian Hospital Sewage and Other Environmental Metagenomes Deposited in Public Databases

“…Such patterns are the result of evolutionary pressure to maintain structures and proteins function. Some previous studies of metagenomes involving mining of target genes as chitinases (Romão-Dumaresq et al, 2014), PKS and NRPS (Cuadrat et al, 2016) used HMM profiles obtaining good results and sensitivity. Our HMM profiles for serine β-lactamases, followed by our RPS-BLAST analysis, revealed most of the retrieved metagenomic sequences belongs to the β-lactamase family, confirming the efficacy of profile approaches for this propose.…”

Analysis of aerobic anoxygenic phototrophic bacterial community structure in the different marine functional zones in the Zhoushan Archipelago Sea Area in summer

“…The community structure and diversity of marine bacteria have also been analyzed by high-throughput sequencing methods (Abell et al 2011;Bowman et al 2012;Comeau et al 2011). And these methods have been used to analyze studies have been conducted to utilize samples from different kinds of aquatic conditions, such as the Amazon River, the North Pacific subtropical gyre, the Mediterranean coastal lagoons, and a coastal bay of Brazil (Cuadrat et al 2016;Ghai et al 2012;Ghai et al 2011;Konstantinidis et al 2009). The amplification of the pufM gene has resulted in extremely deep sequencing of bacterial communities (Luna 2015;Zheng et al 2015).…”