Construction and validation of metagenomic DNA libraries from landfarm soil microorganisms

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Landfarming biodegradation is a strategy used by the petrochemical industry to reduce pollutants in petroleum-contaminated soil. We constructed 2 metagenomic libraries from landfarming soil in order to determine the pathway used for mineralization of benzene and to examine protein expression of the bacteria in these soils. The DNA of landfarm soil, collected from Ilheus, BA, Brazil, was extracted and a metagenomic library was constructed with the Copy Control (TM) Fosmid Library Production Kit, which clones 25-45-kb DNA fragments. The clones were selected for their ability to express enzymes capable of cleaving aromatic compounds. These clones were grown in Luria-Bertani broth plus L-arabinose, benzene, and chloramphenicol as induction substances; they were tested for activity in the catechol cleavage pathway, an intermediate step in benzene degradation. Nine clones were positive for ortho-cleavage and one was positive for meta-cleavage. Protein band patterns determined by SDS-polyacrylamide gel electrophoresis differed in bacteria grown on induced versus non-induced media (Luria-Bertani broth). We concluded that the DNA of landfarm soil is an important source of genes involved in mineralization of xenobiotic compounds, which are common in gasoline and oil spills. Metagenomic library allows identification of non-culturable microorganisms that have potential in the bioremediation of contaminated sites.12221482155Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq [558272/2009-6

Combined carbon and nitrogen removal from acetonitrile using algal-bacterial bioreactors

When compared with Chlorella vulgaris, Scenedesmus obliquus and Selenastrum capricornutum, C. sorokiniana presented the highest tolerance to acetonitrile and the highest O-2 production capacity. It also supported the fastest acetonitrile biodegradation when mixed with a suitable acetonitrile-degrading bacterial consortium. Consequently, this microalga was tested in symbiosis with the bacterial culture for the continuous biodegradation of acetonitrile at 2 g l(-1) in a stirred tank photobioreactor and in a column photobioreactor under continuous illumination (250 mu E m(-2) s(-1)). Acetonitrile removal rates of up to 2.3 g l(-1) day(-1) and 1.9 g l(-1) day(-1) were achieved in the column photobioreactor and the stirred-tank photobioreactor, respectively, when operated at the shortest retention times tested (0.4 days, 0.6 days, respectively). In addition, when the stirred-tank photobioreactor was operated with a retention time of 3.5 days, the microbial culture was capable of assimilating up to 71% and nitrifying up to 12% of the NH4+ theoretically released through the biodegradation of acetonitrile, thus reducing the need for subsequent nitrogen removal. This study suggests that complete removal of N-organics can be combined with a significant removal of nitrogen by using algal - bacterial systems and that further residual biomass digestion could pay-back part of the operation costs of the treatment plant

Biodegradation of acetonitrile by adapted biofilm in a membrane-aerated biofilm reactor

10.1007/s10532-008-9246-7Biodegradation204569-580BIOD

Antisense oligonucleotides: the next frontier for treatment of neurological disorders

Antisense oligonucleotides (ASOs) were first discovered to influence RNA processing and modulate protein expression over two decades ago; however, progress translating these agents into the clinic has been hampered by inadequate target engagement, insufficient biological activity, and off-target toxic effects. Over the years, novel chemical modifications of ASOs have been employed to address these issues. These modifications, in combination with elucidation of the mechanism of action of ASOs and improved clinical trial design, have provided momentum for the translation of ASO-based strategies into therapies. Many neurological conditions lack an effective treatment; however, as research progressively disentangles the pathogenic mechanisms of these diseases, they provide an ideal platform to test ASO-based strategies. This steady progress reached a pinnacle in the past few years with approvals of ASOs for the treatment of spinal muscular atrophy and Duchenne muscular dystrophy, which represent landmarks in a field in which disease-modifying therapies were virtually non-existent. With the rapid development of improved next-generation ASOs toward clinical application, this technology now holds the potential to have a dramatic effect on the treatment of many neurological conditions in the near future