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23 Congress of the International Union for Biochemistry and Molecular Biology
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44 Annual Meeting of the Brazilian Society for Biochemistry and Molecular Biology
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Foz do Iguaçu, PR, Brazil, August 24 to 28 , 2015
VARIATION IN MICROBIAL DIVERSITY AND COMPOSITION IN THE GUT OF THE
AMERICAN COCKROACH Periplaneta americana
Bertino-Grimaldi, D.1 Medeiros; M.N.2; Cardoso, A.M.2; Albano, R.M3; Machado,
E.A1.
1
Laboratório de Entomologia Médica, Instituto de Biofísica Carlos Chagas
Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil; 2Diretoria
de Metrologia Aplicada às Ciencias da Vida, Instituto Nacional de
Metrologia Qualidade e Tecnologia, Rio de Janeiro, Brasil; 3Departamento de
Bioquímica, Universidade do Estado do Rio de
Janeiro, Rio de Janeiro, Brasil.
Currently, lignocellulose-derived fuels are an alternative to fossil fuels; however,
achieve an efficient saccharification of cellulose is still a challenge for secondgeneration ethanol. Insects degrade lignocellulose efficiently using endogenous
enzymes and microorganisms of the intestinal flora, so they have great potential as a
source of biological catalysts. The knowledge of the bacterial communities and the
mechanisms involved in the degradation of lignocellulose is an important step for both
basic research and for biotechnology. The American cockroach Periplaneta americana
is the most common cockroach specie in city sewer systems and can harbor a wide
variety of microorganisms in its gut. However, little is known about the changes in the
diversity and bacterial community structures in response to variation in the anatomical
compartments throughout the insect gut. This study aims to verify the complexity of a
bacterial communities occuring in the gut of the American cockroach on a cellulosebased diet compared with the control diet composed by dog chow and soybean oil. The
insects were kept under the same conditions, varying only the diet. We report the
bacterial taxa of the omnivorous cockroach P. americana and the effects of cellulosic
diet on microbial diversity by ultra-high-throughput sequencing technology. Sequencing
of the hypervariable region V4 of the 16S rRNA genes showed that after two weeks
eating diet exclusively composed of crystalline cellulose there was a shift in the
microbiota arrangement. In the midgut, the population of bacteria of the phylum
Firmicutes decreased, while the hindgut about 70% of the sequences were affiliated to
belong to the phylum Fibrobacteres. When fed on dog chow, phylum Bacteroidetes
microorganisms were predominant in the hindgut. Changes observed in microbiota
assemblage may be influenced by diet that works by selecting more adapted
microorganisms to degrade the polymer ingested by the insect.
Key Words: insect, cellulose, microbiota
Acknowledgements: CNPq
Brazilian Society for Biochemistry and
Molecular Biology (SBBq)