A survey on cultivable heterotrophic bacteria inhabiting a thermally unstratified water column in an Atlantic Rainforest lake

Cláudia I Lima-Bittencourt; Patrícia S Costa; Mariana P Reis; Alexandre B Santos; Francisco A R Barbosa; Jean L Valentin; Fabiano L Thompson; Edmar Chartone-Souza; Andréa M A Nascimento

doi:10.7717/peerj.478

A survey on cultivable heterotrophic bacteria inhabiting a thermally unstratified water column in an Atlantic Rainforest lake

PeerJ. 2014 Aug 26:2:e478. doi: 10.7717/peerj.478. eCollection 2014.

Authors

Cláudia I Lima-Bittencourt¹, Patrícia S Costa¹, Mariana P Reis¹, Alexandre B Santos¹, Francisco A R Barbosa¹, Jean L Valentin², Fabiano L Thompson², Edmar Chartone-Souza¹, Andréa M A Nascimento¹

Affiliations

¹ Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais , Belo Horizonte, Minas Gerais , Brazil.
² Laboratório de Microbiologia, Instituto de Biologia, Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil.

Abstract

Due to the importance of heterotrophic bacteria in biogeochemical cycles and their influence on water quality, many studies have assessed the composition of the bacterial community. Most of these were made in temperate freshwaters. Eighteen heterotrophic bacteria communities distributed over time and space in the water column of Carioca Lake, not exposed to anthropogenic activities, were analyzed to characterize their composition. A polyphasic approach was used, including 16S rDNA restriction analysis, 16S rRNA gene sequence analysis, BIOLOG Ecoplates and statistical methods. The physiological profiles among the 18 microbial communities were diverse. Clustering analysis and the metabolic fingerprint of the Biolog Ecoplate(TM) system data separated the communities based on temporal scale. A set of 673 isolates were recovered on high nutrient medium. The 673 isolates obtained yielded 360 Amplified Ribosomal DNA Restriction Analysis (ARDRA) Operational Taxonomic Units (OTUs). Most (313) of the ARDRA patterns, OTUs, were from isolates obtained in a single sampling point, in temporal and spatial scales, indicating changes in the bacterial community. A subset of representative isolates for each ARDRA OTU was identified by 16S rRNA gene fragment sequencing and categorized into five phyla, Proteobacteria, Actinobacteria, Bacteroidetes, Firmicutes, and Deinococcus-Thermus, represented by 38 genera. The results of this work contribute to a better understanding about the phylogeny of tropical freshwater heterotrophic bacteria.

Keywords: Bacteria; 16S rRNA; Tropical freshwater lake.

Grants and funding

Financial support of this project was received from the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq PELD, Programa Ecológico de Longa Duração, 472411/2012-8), the Pró-Reitoria de Pesquisa da UFMG (PRPq), and the Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG, 00801-12). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.