Isolamento e caracterização de compostos bioativos da peçonha da aranha caranguejeira Lasiodora sp.

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Biologia Animal, 2009.A peçonha de aranhas constitui-se como um conjunto diverso de moléculas bioativas, usado para subjugar a presa e eventualmente para defesa. Essas moléculas atuam de formas variadas em muitos sistemas biológicos e despertam interesse pelo seu potencial para a prospecção de produtos naturais. Pouco se sabe sobre as peçonhas de aranhas caranguejeiras do Brasil. Este estudo apresenta a caracterização de componentes da peçonha de Lasiodora sp. bem como sua atividade biológica. Foram detectados 191 componentes na peçonha de Lasiodora sp. com predominância de componentes com massa molecular menor que 1000 Da e entre 4000 e 8500 Da. A atividade cardiotóxica foi atribuída aos componentes de baixo peso molecular da peçonha. Quatro peptídeos tiveram sua estrutura primária parcialmente elucidada. A análise de similaridade desses peptídeos isolados e caracterizados sugeriu a atividade em canais iônicos, que não foi detectada nos ensaios eletrofisiológicos. A peçonha bruta de Lasiodora sp. inibiu de maneira significativa o crescimento das bactérias Escherichia coli e Staphylococcus aureus. A atividade antibacteriana foi identificada em oito frações cromatográficas e em um grupo de frações com baixa massa molecular (JL1), sendo que não foi possível a determinação de MIC. Este estudo contribui para a compreensão da diversidade e complexidade da peçonha da aranha Lasiodora sp., bem como preenche lacunas até então não esclarecidas para essa espécie. _______________________________________________________________________________ ABSTRACTThe spider venom is a diverse set of bioactive molecules, used to subdue the prey and possibly for defense. These molecules act in various forms in many biological systems and arouse interest in its potential for the exploration of natural products. Little is known about the Tarantula venoms from Brazil. This study presents the characterization of components from the venom of Lasiodora sp. and its biological activity. We identified 191 molecular mass components in the Lasiodora sp. venom, with prevalence of components smaller than 1000 Da and between 4000 and 8500 Da. The cardiotoxic activity was attributed to low molecular weight components. Four peptides had their primary structure partially elucidated. The analysis of similarity of these isolated and characterized peptides suggest activity on ion channels, which was not detected in the electrophysiological testing. The Lasiodora sp. crude venom significantly inhibited the bacteria Escherichia coli and Staphylococcus aureus growth. The antibacterial activity was identified in eight chromatographic fractions, and in a group of low molecular weight fractions (JL1), which was not possible to determine MIC. This study contributes to understanding the diversity and complexity of the venom of the spider Lasiodora sp. and then fills gaps unclear for this species

Draft Genome Sequence of Stenotrophomonas maltophilia Strain PE591, a Polyethylene-Degrading Bacterium Isolated from Savanna Soil.

We report the genome sequence of a polyethylene-degrading bacterial strain identified as Stenotrophomonas maltophilia strain PE591, which was isolated from plastic debris found in savanna soil. The genome was assembled in 16 scaffolds with a length of 4,751,236 bp, a GC content of 66.5%, and 4,432 predicted genes

Draft Genome Sequence of Stenotrophomonas maltophilia Strain PE591, a Polyethylene-Degrading Bacterium Isolated from Savanna Soil.

We report the genome sequence of a polyethylene-degrading bacterial strain identified as Stenotrophomonas maltophilia strain PE591, which was isolated from plastic debris found in savanna soil. The genome was assembled in 16 scaffolds with a length of 4,751,236 bp, a GC content of 66.5%, and 4,432 predicted genes

Muricauda brasiliensis sp. nov., isolated from a mat-forming cyanobacterial culture

Strain K001 was isolated from a cyanobacterial culture derived from Abrolhos, a reef bank microbial mat (South Atlantic Ocean—Brazil). Cells of K001 are Gram stain–negative, catalase and oxidase-positive, non-motile, rod-shaped, and with or without appendages. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain K001 belongs to the genus Muricauda. The highest strain K001 16S rRNA gene identity, ANI, and dDDH, respectively, are with M. aquimarina (98.90%, 79.23, 21.60%), M. ruestringensis (98.20%, 80.82, 23.40%), and M. lutimaris (97.86%, 79.23, 22.70%). The strain grows at 15–37 °C and between 0.5 and 10% NaCl. The major fatty acids of strain K001 are iso-C15:0, iso-C15:1 G, iso-C17:0 3-OH, and summed feature 3 (C16:1 ω6c and/or C16:1 ω7c). The polar lipids are represented by phosphatidylethanolamine, three unidentified aminolipids, and three unidentified polar lipids. The major respiratory quinone is MK-6. The G+C content of the DNA of strain K001 is 41.62 mol%. Based on polyphasic analysis of strain K001, it was identified as a novel representative of the genus Muricauda and was named Muricauda brasiliensis sp. nov. The type strain is K001 (=CBMAI 2315T = CBAS 752T)