|1004-1||Endoglucanase-producing clones from mangroves sediments metagenomes|
|Autores:||Fábio Lino Soares Júnior (CENA/USP - Center for Nuclear Energy in Agriculture / ESALQ/USP - Department of Genetics / ESALQ/USP - Department of Soil Science) ; Joelma Marcon (ESALQ/USP - Department of Genetics) ; Myllene Pinheiro (ESALQ/USP - Department of Soil Science) ; Giulia Mazzero Inocêncio (ESALQ/USP - Department of Genetics) ; Maria Caroline Quecine (ESALQ/USP - Department of Genetics) ; João Lúcio Azevedo (ESALQ/USP - Department of Genetics) ; Valéria Maia (UNICAMP - Department of Genetics and Molecular Biology) ; Fernando Dini Andreote (ESALQ/USP - Department of Soil Science) |
Mangrove ecosystems are characterized by long coastal strip, located at the interface between land and ocean. Due to its proximity to oceans and changes in tides, this biome is able to select microbial communities adapted to the variations of salinity and oxygen availability, with essential role on the degradation of organic compounds and nutrients availability. Hence, it became important, on the light of microbial ecology and biotechnology, to insight on the microbial groups responsible for the breakdown of organic compounds, as cellulose, in such particular ecosystem. Here we show a survey on the finding of endoglucanase producer clones in a fosmid-based metagenomic library (average insert size 30Kb) built from DNA obtained in a oil spilled mangrove area, located in the city of Bertioga (São Paulo, Brazil). A total of 12,960 clones were screened in minimum medium amended with 1% of carboxymethil-cellulose (CMC), with further staining with iodine, resulting in the observation of degradation halos around four clones. The kinetics growth of such clones was determined, and the CMC degradation was confirmed by the release of reducing sugars (Somogyi-Nelson test). All results of measurements were normalized to a control treatment (fosmid-free E.coli). The rate or reducer sugar releases was different among clones, indicating the differential composition of environmental DNA insert, as clone H8 have a higher activity (0.44 nmol/min/ml) when compared to others; H9 (0.23 nmol/min/ml), G7 (0.19 nmol/min/ml) and F10 (0.11 nmol/min/ml). These results dos indicate the presence of endoglucanase codifying genes in the library, and pose the question about the organisms carrying such genes, and how it is modulated by the environmental conditions found in mangroves. The future prospects will target these issues, highlighting the ecology and possible usage of microbial groups involved in biomass degraders in the particular conditions of mangroves sediments.
Palavras-chave: biotechnology, carboxymethil-cellulose, metagenomic library, microbial ecology, Somogyi-Nelson test