Chitinolytic bacteria are autochthonous and extremely important in the marine ecosystem. They have key role in nutrient cycling through the chitin degradation in the water column. The hydrolysis of chitin is performed by enzymes called chitinases, which have many functions in nature. Different bacterial chitinases, such as endochitinases, chitobiosidases and N-acetyl-glucosaminidases have been described in the literature. These enzymes have different mechanisms of hydrolysis and may be used for various biotechnological purposes. Based on the great importance of chitinolytic bacteria in the marine ecosystem and looking for bacterial chitinase to use in biotechnological processes, it began in 2005 a study on the diversity of chitinolytic bacteria in the brazilian marine ecosystem. In this study, it was performed sampling of seawater and plankton in São Sebastião, Ubatuba and Santos between 2005 and 2007. All chitinolytic bacteria were analyzed for their ability to degradation of chitin, obtaining 12 bacteria of the Aeromonas genus with greater ability to degradation. This study aims to select the best conditions for the cultivation of this 12 bacteria using three variables (temperature, chitin concentration and pH), to evaluate the behavior of these isolates on chitin degradation during 96 hours of cultivation under pre-determined conditions by three methods (halo of chitin hydrolysis, high-performance liquid chromatography and Antrona test) and by chitinolytic activity of three enzymes (N-acetyl-glucosaminidase, chitobiosidase and endochitinase). Moreover, characterize them by 16S rRNA gene full sequencing and Multilocus Sequence Analysis (MLSA) using three housekeeping genes (recA, rpoB, and rpoD). This study is extremely important to give support to future studies involving chitinolytic bacteria and to know the behavior of chitinases and marine isolates that could be used in biotechnological processes.
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