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Bacterioplankton diversity of the tropical coast of Brazil

2016; Frontiers Media; Volume: 3; Linguagem: Inglês

10.3389/conf.fmars.2016.05.00175

2296-7745

Saes Renan, Colares Geórgia, Melo Vânia, Lotufo Letícia,

Coastal and Marine Management

Event Abstract Back to Event Bacterioplankton diversity of the tropical coast of Brazil Renan V. Saes1*, Geórgia B. Colares1, Vânia M. Melo1 and Letícia V. Lotufo1, 2 1 Federal University of Ceará - UFC, Institute of Science Sea - labomar, Brazil 2 University of São Paulo - Oceanographic Institute, Brazil In the marine environment phytoplankton plays an important ecological function due to their ability to convert solar energy into organic compounds, ensuring its own maintenance and reproduction, besides the production of molecular oxygen released into the atmosphere as organic compounds. For these characteristics, the phytoplankton is the base of the marine food chain and ensures the maintenance of life on Earth by procuding oxigen. The smallest fraction of plankton is called bacterioplankton it is directly involved in biogeochemical processes and are the key to nutrient cycling, especially for carbon cycling in microbial loop. The brasilian coast is widely diverse, with different morphological features and water masses. Among them, several environments are influenced by estuarine systems. The bacterioplankton diversity is associated with physical and chemical factors such as temperature and light availability. Running water and nutrient availability are also limiting factors. Warm waters and high light incidence are characteristics of the Ceara state in the northeastern portion of Brazil (latitude 3o), it also contains the continetal contribution of several estuarine systems along the coast. On the other hand, in southeastern Brazil, the state of Rio de Janeiro, has an area of feature resurgence, emerging water rich in nutrients on the platform (continental waters of the South Atlantic). Due to the small size (3um) and not morphological differentiation (beads) of cyanobacteria (main group within the bacterioplankton), taxonomy is made by moleculaes techniques involving molecular stopwatch RNA16s gene. The technique of electrophoresis on denaturing gradient gel (DGGE) is a fingerprint to analyze the different structures in different communities of bacterial ecosystem. The amplified DNAs from different samples have different nucleotide compositions, generating a characteristic pattern of bands from each community. The goal of this study was to assess different ecological patterns of diversity and wealth of smaller fraction of plankton in the tropical coast of Brazil considering the different regions and input. DNA samples of cyanobacteria of three beaches in the state of Ceará (PA1, PP1, IC1) and two beaches in Rio de Janeiro (AR1 and AR2) were amplified (semi-nested PCR) using specific primers for these groups. Different patterns of bands were considered OTUs (operational taxonomic units) in polyacrylamide gel 6% in a denaturing gradient of 45-55%. DNA labeled with SYBR® Green (Invitrogen) in buffer TAE 1X, using ultraviolet photo documentation system. As a DNA size standard it was used a molecular weight marker 1Kb DNA (Invitrogen). One can compare the different richness and diversity of the samples using the statistical package BioNumerics®. After a similarity analysis (cluster) the samples were divided into two major groups, gathering the OTUs of Rio de Janeiro (AR1 and AR2) in relation to the Ceará samples, with 4 endemisms (Figure 1). Within the samples from northeastern Brazil beach IC1 showed a greater similarity OTUs with each other (82%), and also the most dissimilar to the others. The IC1 replications also had the lowest richness and no pattern of endemism OTUs (Table 1). Replicates of PA1 and PP1 had the highest richness. Although, they have shown a high variability between them (only 33.6% similarity) and well separated from other samples (Figure 1). The richness of PA1 and PP1 were really close to average replicates of 19.6% and 20.3%, respectively. Also, they were similar in taxonomic endemism 4 OTUs for PP1 and 5 for PA1 (Table 1). Table 1 - Relative richness of cyanobacteria OTUs along the Brazilian coast in 2015. Sample ID N° OTUs % OTUs* PP1FA 20 38,46 PP1FC' 21 40,38 PP1FD 20 38,46 PA1FD 17 32,69 PA1FA' 22 42,31 PA1FB' 20 38,46 IC1FB 15 28,85 IC1FC 15 28,85 IC1FE 15 28,85 AC1FA 18 34,62 AC1FC 18 34,62 AC2FA 17 32,69 AC2FC' 17 32,69 Note: * considering total of 52 bands (OTUs) Richness patterns followed the ones of diversity for almost all samples, with the highest diversity in a row PP1 replicate PA1 (Figure 1 and 2). A variance analysis (PCA) has shown that the replicates of PA1 are more uniform, featuring a more homogeneous pattern of abundances of OTUs of bacterioplankton (Figure 3). IC1 had the lowest richness and also less diversity. The richness and diversity of samples of Rio de Janeiro were slightly below samples of PP1 and PA1 and higher than the samples IC1 (Figure 2), however the PCA demonstrates that these were grouped with samples of IC1 when grouped only by the abundance (Figure 3). Due to the different conditions of temperature and seasonal variations it was expected a difference in bacterioplankton diversity along the giant Brazilian coast. Although, in northeastern Brazil, represented in this study by Ceará, its beaches are influenced by river input, on the other hand, the high upwelling of Rio de Janeiro brings increased nutrient load from the platform of the bottom waters. As nutrients are limiting the stabilization of phytoplankton population it was expected greater abundance in phytoplankton from samples of AC1 and AC2 but the analysis grouped these with IC1, having less richness and less diversity. During the collection of the AC, temperature of the water was very low (13oC) due to the resurgence thermocline. Populations of cyanobacteria may have been selected drastically reducing the microalgae proliferation. The beach IC1 has a different pattern of other Ceará beaches with shallow and dark waters with many sediment particles in the water column from the mangroves in the vicinities. This factor may have limited the entry of light and thus justifying the low diversity and abundance. PA1 and PP1 had the highest diversity and richness, they have clear waters and high temperatures and are near to the mouths of large rivers. So, the light, temperature and nutrients do not present limitations to such species. Although, this study presents an initial background of the smaller planktonic fractions in different regions of Brazil. More parameters should be evaluated, as the nutrient load in specific and even more detailed evaluation in different seasonality to determine the correct pattern of bacterioplankton communities of the Brazilian coast. Figure 1 Figure 2 Figure 3 Keywords: Cyanobacteria, DGGE, Ecology, richness, Genetics Conference: XIX Iberian Symposium on Marine Biology Studies, Porto, Portugal, 5 Sep - 9 Sep, 2016. Presentation Type: Poster Presentation Topic: 1. ECOLOGY, BIODIVERSITY AND VULNERABLE ECOSYSTEMS Citation: Saes RV, Colares GB, Melo VM and Lotufo LV (2016). Bacterioplankton diversity of the tropical coast of Brazil. Front. Mar. Sci. Conference Abstract: XIX Iberian Symposium on Marine Biology Studies. doi: 10.3389/conf.FMARS.2016.05.00175 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 30 Apr 2016; Published Online: 03 Sep 2016. * Correspondence: DVM, PhD. Renan V Saes, Federal University of Ceará - UFC, Institute of Science Sea - labomar, Fortaleza, CE, 60135-081, Brazil, r_vandre@hotmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Renan V Saes Geórgia B Colares Vânia M Melo Letícia V Lotufo Google Renan V Saes Geórgia B Colares Vânia M Melo Letícia V Lotufo Google Scholar Renan V Saes Geórgia B Colares Vânia M Melo Letícia V Lotufo PubMed Renan V Saes Geórgia B Colares Vânia M Melo Letícia V Lotufo Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.