Microbial Community Profile and Water Quality in a Protected Area of the Caatinga Biome

PLoS One. 2016 Feb 16;11(2):e0148296. doi: 10.1371/journal.pone.0148296. eCollection 2016.

Abstract

The Caatinga is a semi-arid biome in northeast Brazil. The Paraguaçú River is located in the Caatinga biome, and part of its course is protected by the National Park of Chapada Diamantina (PNCD). In this study we evaluated the effect of PNCD protection on the water quality and microbial community diversity of this river by analyzing water samples obtained from points located inside and outside the PNCD in both wet and dry seasons. Results of water quality analysis showed higher levels of silicate, ammonia, particulate organic carbon, and nitrite in samples from the unprotected area compared with those from protected areas. Pyrosequencing of the 16S rRNA genes revealed that Burkholderiales was abundant in samples from all three sites during both seasons and was represented primarily by the genus Polynucleobacter and members of the Comamonadaceae family (e.g., genus Limnohabitans). During the dry season, the unprotected area showed a higher abundance of Flavobacterium sp. and Arthrobacter sp., which are frequently associated with the presence and/or degradation of arsenic and pesticide compounds. In addition, genes that appear to be related to agricultural impacts on the environment, as well as those involved in arsenic and cadmium resistance, copper homeostasis, and propanediol utilization, were detected in the unprotected areas by metagenomic sequencing. Although PNCD protection improves water quality, agricultural activities around the park may affect water quality within the park and may account for the presence of bacteria capable of pesticide degradation and assimilation, evidencing possible anthropogenic impacts on the Caatinga.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agriculture
  • Ammonia / analysis
  • Arthrobacter / classification*
  • Arthrobacter / genetics
  • Brazil
  • Burkholderiaceae / classification*
  • Burkholderiaceae / genetics
  • Carbon / analysis
  • Comamonadaceae / classification*
  • Comamonadaceae / genetics
  • Ecosystem
  • Flavobacterium / classification*
  • Flavobacterium / genetics
  • High-Throughput Nucleotide Sequencing
  • Metagenome
  • Microbial Consortia / physiology
  • Nitrites / analysis
  • Particulate Matter / analysis
  • Phylogeny
  • RNA, Ribosomal, 16S / genetics*
  • Rivers / chemistry
  • Rivers / microbiology*
  • Seasons
  • Silicates / analysis
  • Water Quality*

Substances

  • Nitrites
  • Particulate Matter
  • RNA, Ribosomal, 16S
  • Silicates
  • Carbon
  • Ammonia

Grant support

This work was supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico – CNPq – and Instituto Chico Mendes de Conservação da Biodiversidade – ICMBio – (grant number 551994/2011-8; www.cnpq.br; www.icmbio.gov.br). The authors are grateful for the support offered by Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) and National Park of Chapada Diamantina. F.A.C.L. is supported by a Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) fellowship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.