Anuário do Instituto de Geociências (Jul 2007)
Chroococcales em Esteiras Microbianas em Bolha do Brejo do Pau Fincado, Rio de Janeiro, Brasil.
Abstract
Chroococcales in blister microbial mats at brejo do Pau Fincado, Rio de Janeiro, Brazil.Brejo do Pau Fincado (220 55’ 56,75” S e 420 16’ 54,7” W) is a natural natural coastal aquatical body. It is located at the Lagoa de Araruama complex, formed at least 7000 years ago. The local climate is characterized by low precipitation ratesand high evaporation rates; due to this, the lagoons tend to become ypersalyne. Microbial mats are organic-sedimentary structures composed mainly of cyanobacteria. Whilst the photosynthesis process cyanobacteria induct an environmental change, which leads to calcium carbonate precipitation. The aim of this study was to typify and identify the cyanobacteria at the blister microbial mat. Samples were processed and analyzed using an optical microscope. The blister mat is composed of twelve species of cyanobacteria disposed in a fragile and amorphous mass. In this structure, both quantitative andqualitative domains belong to Chroococcales Westtein 1924. Measurement has shown that the place is very selective, andcyanobacteria presented great resistance and adaptability, because they are forms which had got success surviving to big changes occurred on Earth since the beginning of life and the evolutionary history .
