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 (22º55' 56,75" S e 42º16' 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 rates and high evaporation rates; due to this, the lagoons tend to become hypersalyne. 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 and qualitative domains belong to Chroococcales Westtein 1924. Measurement has shown that the place is very selective, and cyanobacteria 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.

Lagoa Salgada: An Overview of a Brazilian Hypersaline Lagoon Environmental Studies Over the Last 5000 Years Using Radiocarbon Date Corrections

“…These organisms are believed to have dominated 80% of all geological formations on planet Earth and are the oldest evidence of life found, dating back to around 3.5 billion years (Vologdin 1962;Hofmann 1969Hofmann , 1973Walter 1976;Grotzinger and Knoll 1999;Riding and Awramik 2000). In addition, they represent a great material in research areas like carbon sources studies (Braissant et al 2004), petrography (Awramik and Buchheim 2012;Pizarro and Branco 2012), and paleoclimatic reconstruction (Vasconcelos and McKenzie 1997;Silva e Silva and Senra 2000;Vasconcelos et al 2006;Iespa et al 2012;Bahniuk 2013;Birgel et al 2015;Carvalho et al 2017).…”

Análise tafonômica e paleoecológica de estruturas associadas a comunidades microbianas holocênicas e permianas

“…), all with similar physico-chemical characteristics Iespa and Damazio-Iespa, 2009;Spadofora et al, 2010;Delfino et al, 2012). The literature review shows that most of the studies of microbialites and microbial mats in Rio de Janeiro state were designed to classify the cyanobacteria that form them (e.g., Silva-e-Silva et al, 2004, 2006b, 2007c, 2007dSilva-e-Silva and Senra, 2000;Silva-e-Silva and Carvalhal, 2005;. Studies of their diagenesis during the Holocene are less frequent Silva-e-Silva et al, 2007b;Senra et al, 2006;Iespa et al, 2011b;McKenzie and Vasconcelos, 2009;Spadofora et al, 2010).…”