Seasonal microbial ribotype shifts in the sulfurous karstic lakes Cisó and Vilar, in northeastern Spain

Authors

  • Sergio Ramírez-Moreno Department of Genetics and Microbiology, Autonomous University of Barcelona, Bellaterra, Spain
  • Maira Martínez-Alonso Department of Genetics and Microbiology, Autonomous University of Barcelona, Bellaterra, Spain
  • Sebastián Méndez-Álvarez Research Unity, Hospital Ntra. Sra. Candelaria, Department of Cellular Biology and Microbiology, University of La Laguna, Santa Cruz de Tenerife, Spain
  • Núria Gaju Department of Genetics and Microbiology, Autonomous University of Barcelona, Bellaterra, Spain

Keywords:

Domain Bacteria, sulfurous lakes, seasonal shifts, 16S rRNA genes, restriction fragment length polymorphism (RFLP), multidimensional scaling (MDS)

Abstract

Spatio-temporal changes in two sulfurous lakes from the karstic area of Banyoles (Girona, Spain), holomictic lake Cisó and meromictic lake Vilar, were studied over one year. Samples were collected at different depths from the two lakes on the same days, during each of the four seasons, and several physico-chemical variables (temperature, light, pH, conductivity, sulfide, oxygen concentration, pigment concentrations, etc.) were measured. To fingerprint bacterial populations from each sample, DNA was extracted, bacterial 16S rRNA genes were amplified by PCR, and restriction fragment length polymorphism (RFLP) analyses of the total bacterial 16S rDNAs were performed. Each 16S rDNA pool was independently digested with three restriction endonucleases (AluI, HinfI, and RsaI) and separated electrophoretically. More restriction fragments were obtained from the Lake Vilar samples than from the Lake Cisó samples. Moreover, intrasample and intersample differences were observed in each lake. RFLP patterns were compared by scoring similarities using the Jaccard coefficient and then building a multidimensional scaling (MDS) map from the resulting similarities matrix. In both lakes, results indicated that seasonality was mostly responsible for the observed fluctuations in the RFLP patterns, while the effect of stratification was less pronounced. [Int Microbiol 2005; 8(4):235-242]

Downloads

Published

2010-02-26

Issue

Section

Research Articles