The Atlantic Rainforest does not have a uniform physiognomy, its relief determines different environmental conditions that define the composition of its flora and fauna. Within this ecosystem, bromeliads that form tanks with their leaves hold water reservoirs throughout the year, maintaining complex food chains, based mainly on autotrophic and heterotrophic bacteria. Some works concluded that the water held by tank bromeliads concentrate the microbial diversity of their ecosystem. To investigate the bacterial diversity and the potential biotechnology of these ecosystems, tank bromeliads of the Neoregelia cruenta species from the Atlantic Rainforest in Brazil were used as models for this research. Bacteria isolated from these models were tested for production of bioactive compounds. DGGE of the water held by tank bromeliads was performed in different seasons, locations and sun exposure to verify whether these environmental factors affect bacterial communities. The DGGE bands profile showed no grouping of bacterial community by the environmental factors tested. Most of the isolates demonstrated promising activities in the tests performed. Collectively, these results suggest that tank bromeliads of the N. cruenta species provide important habitats for a diverse microbial community, suggesting that each tank forms a distinct micro-habitat. These tanks can be considered excellent sources for the search for new enzymes and/or new bioactive composites of microbial origin. © 2014, Sociedade Brasileira de Microbiologia.