Dynamics of anaerobic bacteria in the final steps of organic matter mineralization in the Carretas-Pereyra and Chantuto-Panzacola ecosystems

Abstract

The coastal sediments are important sites for the organic matter mineralization. In this ecosystems, where there is a constant input of sulfates, the sulfate reducing bacteria are the most important microorganisms implicated in the last anaerobic steps of mineralization; however the methanogenic bacteria are also important. There are several studies about the function of this anaerobic bacterial communities, mostly them in temperate regions. The aim of this study was investigate the seasonal and, spatial dynamics of sulfate reducing and, methanogenic bacteria in two coastal lagoons sediments located in Chiapas State. Sediment samples was collected at different months. The sulfate reducing and, methanogenic bacteria were evaluated with Most Probable Number technique using different substrates. Several physical and, chemical parameters was too measured. The sulfate reducing and, methanogenic bacteria were abundant in both coastal lagoons sediments. The bacterial density in the coastal lagoons studied was highest than the reported it in coastal and, freshwater sediments located in temperate regions. Seasonal and, spatial variations of the anaerobic bacterial populations were related with salinity, sulfate concentration and pH.