Diversity assessment of photosynthesizers: comparative analysis of pre-cultivated and natural microbiome of sediments from Cerrado biome in Maranhão, Brazil.

Photosynthetic microorganisms are important components of most ecosystems and have important roles regarding biogeochemical cycles and the basis of the trophic chain. However, they sometimes are present in low abundance compared to other heterotrophic organisms. The Chapada das Mesas National Park (PNCM) is a Conservation Unit in Brazilian Cerrado biome, which is considered a hotspot for biodiversity conservation and possesses important rivers, waterfalls, and springs with economical and touristic importance.

Microbial perspective on the giant carbonate ridge Alpha Crucis (Southwestern Atlantic upper slope).

Deep-sea carbonate mounds can harbor a wide variety of heterotrophic and chemosynthetic microbial communities, providing biodiversity hotspots among the deep-sea benthic ecosystems. This study examined the bacterial and archaeal diversity and community structure in the water column and sediments associated with a recently described giant carbonate mound named Alpha Crucis Carbonate Ridge (ACCR), located in the Southwestern Atlantic Ocean. Because of the acoustic evidence of gas chimneys from a previous study, we further evaluated the chemosynthetic primary production through in situ-simulated dark carbon fixation rates.