Tank bromeliad water: similar or distinct environments for research of bacterial bioactives?

Abstract

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.

Bromeliad tanks are unique habitats for microbial communities involved in methane turnover

“…Previous studies have shown that exposure to sun or shade affects the composition and diversity of aquatic insect in the water of bromeliads (Lopez and Rios 2001). However, Carmo et al (2014) reported that bacterial communities in tank water showed no grouping by the environmental factors tested (e.g season, sun exposure). The bacterial communities in Costa Rican tank bromeliads were affected by acid-base conditions (Goffredi et al 2011b).…”

“…Sampling time points or sampling intervals may play a major role in order to detect controls on microbial community composition in tank bromeliad wetlands. In contrast to other studies, which lasted up to years (Carrias et al 2001;Goffredi et al 2011b;Carmo et al 2014), our study captured only a snapshot in time. However it is to be emphasized, that due to different water availabilities the microbial community composition in tank slurry can dramatically change even within days (Brandt et al 2014).…”

“…The bacterial communities in Costa Rican tank bromeliads were affected by acid-base conditions (Goffredi et al 2011b). However, it should be noted that sampling strategies were different in previous studies using either the tank water (Carmo et al 2014;Farjalla et al 2012) or tank slurry to investigate bacterial communities (Goffredi et al 2011b). These differences complicate a direct comparison between the studies and may possibly lead to an underestimation or exclusion of resident microbial organisms.…”

“…Diverse communities of macro-and microorganisms inhabit these tanks and are responsible for the breakdown of tank organic matter, the release of plantavailable nutrients (Ngai and Srivastava 2006) and the emission of substantial amounts of CH 4 (Martinson et al 2010) and CO 2 (Atwood et al 2013). Tank bromeliads were used as natural model systems to study food web structures (Kitching 2001;Srivastava 2006;Srivastava et al 2008;Brouard et al 2011), animal richness (Richardson 1999), activity and distribution of (aquatic) invertebrates (Carrias et al 2001;Marino et al 2013) and microorganisms (Carmo et al 2014). Many different bacteria and archaea, which are commonly found in soils, were also detected in Ecuadorian and Costa Rican tank bromeliad slurries (Goffredi et al 2011a(Goffredi et al , 2011bMartinson et al 2010).…”

“…Due to their high abundance tank bromeliads may therefore represent important habitats for microorganisms involved in the cycling of carbon and nitrogen (Goffredi et al 2011b). Recently, Carmo et al (2014) observed a large variation in the community structure when investigating the bacteria in the tank water of different Neoregelia cruenta bromeliads. Similar results were reported by Farjalla et al (2012) evaluating the microbial community in the tank water of four bromeliad species.…”