Resumo

Mangrove is considered a model for studies in stress tolerant environment due showed high salinity, anaerobiotic zones and other characteristics that exert a high selective pressure on microorganisms that lived there. Therefore, microorganisms developed different strategies to adapt to these conditions and survive on this environment. To understand the mechanisms involved on adaptation of microbial communities to this stressful environment, we developed this work using independent-culture methodologies to access the role of genetic mobile elements (GME - associated with microbial genetic adaptation) on microbial community adaptations. We constructed a fosmid library using a DNA of total microbial community extract of an oil-contaminated mangrove soil located in São Paulo state. This specific mangrove was chosen because the organisms able to live on this specific mangrove needs to be adapted to local conditions and furthermore to the selective pressure exerted by oil-contamination. Thus, from fosmid library was constructed contigs, and only contigs that showed length above 30.000 bp was selected for the analysis, representing a total of 189 contigs. All this 189 contigs showed GME inserted on these sequences. Moreover, 32 showed tRNA sequences associated with GME, indicating the occurrence of genomic island on these contigs. Beyond this, in all contigs were identified palindromic sequences and insert sequence element (IS). The most prevalent IS family identified were IS3, IS5, IS110, IS21 and IS66. The IS3 family was related to flank genes related to citrate utilization and Clp protease (chaperone family). It is possible to observe on these contigs genes related to organic matter consumption (hydrolases) and genes involved on energetic mechanisms, as sulphate respiration among others. These functions were very important to maintain mangrove soil. More studies were doing with these contigs for try to understand the functions that could be changing between microorganisms and its role on adaptation and environment functioning.