BackgroundAmong viruses, bacteriophages are a group of special interest due to their capacity of infecting bacteria that are important for biotechnology and human health. Composting is a microbial-driven process in which complex organic matter is converted into humus-like substances. In thermophilic composting, the degradation activity is carried out primarily by bacteria and little is known about the presence and role of bacteriophages in this process.ResultsUsing Pseudomonas aeruginosa as host, we isolated three new phages from a composting operation at the Sao Paulo Zoo Park (Brazil). One of the isolated phages is similar to Pseudomonas phage Ab18 and belongs to the Siphoviridae YuA-like viral genus. The other two isolated phages are similar to each other and present genomes sharing low similarity with phage genomes in public databases; we therefore hypothesize that they belong to a new genus in the Podoviridae family. Detailed genomic descriptions and comparisons of the three phages are presented, as well as two new clusters of phage genomes in the Viral Orthologous Clusters database of large DNA viruses. We found sequences encoding homing endonucleases that disrupt a putative ribonucleotide reductase gene and an RNA polymerase subunit 2 gene in two of the phages. These findings provide insights about the evolution of two-subunits RNA polymerases and the possible role of homing endonucleases in this process. Infection tests on 30 different strains of bacteria reveal a narrow host range for the three phages, restricted to P. aeruginosa PA14 and three other P. aeruginosa clinical isolates. Biofilm dissolution assays suggest that these phages could be promising antimicrobial agents against P. aeruginosa PA14 infections. Analyses on composting metagenomic and metatranscriptomic data indicate association between abundance variations in both phage and host populations in the environment.ConclusionThe results about the newly discovered and described phages contribute to the understanding of tailed bacteriophage diversity, evolution, and role in the complex composting environment.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-017-3729-z) contains supplementary material, which is available to authorized users.

RESUMOConsiderando as grandes as inquietações da sociedade moderna frente aos diagnósticos ambientais e seus efeitos na degradação da saúde, este artigo teve como objetivo fazer uma revisão com base na literatura sobre o lixo eletrônico, suas conseqüências e possíveis soluções para este problema no Brasil. A Política Nacional dos Resíduos Sólidos constitui-se em um instrumento poderoso e consciente da necessidade alarmante de proteção do meio ambiente, agasalhando também a dignidade da pessoa humana e do seu direito à saúde, uma vez que o Brasil é o mercado emergente que gera o maior volume de lixo eletrônico per capta anual. Palavras-Chaves: Lixo eletrônico, poluição eletrônica, resíduo sólido. ABSTRACTConsidering the major concerns of modern society in the face of environmental diagnoses and their effects on the degradation of health, this article aims to do the review of literature based about electronic waste, its consequences and possible solutions for this problem in Brazil. The National Solid Waste Policy consists in a powerful and aware of the alarming need to protect the environment, also wrapping human dignity and their right to health. Since Brazil is the emerging market that generates the largest volume of electronic waste per capita annual.

Considerando as grandes as inquietações da sociedade moderna frente aos diagnósticos ambientais e seus efeitos na degradação da saúde, este artigo teve como objetivo fazer uma revisão com base na literatura sobre o lixo eletrônico, suas conseqüências e possíveis soluções para este problema no Brasil. A Política Nacional dos Resíduos Sólidos constitui-se em um instrumento poderoso e consciente da necessidade alarmante de proteção do meio ambiente, agasalhando também a dignidade da pessoa humana e do seu direito à saúde, uma vez que o Brasil é o mercado emergente que gera o maior volume de lixo eletrônico per capta anual. Palavras-Chaves: Lixo eletrônico, poluição eletrônica, resíduo sólido.

Surface adhesion strategies are widely employed by bacterial pathogens during establishment and systemic spread in their host. A variety of cell surface appendages such as pili, fimbriae and afimbrial adhesins are involved in these processes. The phytopathogen Xylella fastidiosa employs several of these structures for efficient colonization of its insect and plant hosts. Among the adhesins encoded in the X. fastidiosa genome, three afimbrial adhesins, XadA1, Hsf/XadA2, and XadA3, are predicted to be trimeric autotransporters with a C-terminal YadA-anchor membrane domain. We analyzed the individual contributions of XadA1, XadA2, and XadA3 to various cellular behaviors both in vitro and in vivo. Using isogenic X. fastidiosa mutants, we found that cell-cell aggregation and biofilm formation were severely impaired in the absence of XadA3. No significant reduction of cell-surface attachment was found with any mutant under flow conditions. Acquisition by insect vectors and transmission to grapevines were reduced in the XadA3 deletion mutant. While the XadA3 mutant was hypervirulent in grapevines, XadA1 or XadA2 deletion mutants conferred lower disease severity than the wild-type strain. This insight of the importance of these adhesive proteins and their individual contributions to different aspects of X. fastidiosa biology should guide new approaches to reduce pathogen transmission and disease development.

The Cellular Biology and Molecular Biology are fields of Science that use very abstract concepts, because they look into microscopic and molecular aspects of the nature. The process of teaching/learning of those disciplines requires didactic material, as an alternative approach for the students, to increase the chances of understanding these issues and to become an important tool in the synthesis of this knowledge. One of the methods that can be employed is the didactic models based on multimedia, because they allow an easy and fun interaction with these subjects. On this work was created a new educational model that represents the human mitochondrial DNA molecule, mtDNA, in its circular form, using the softwares Excel 2007 and PowerPoint 2007. The model was constructed in hypertext format, which allowed a quick and interactive access to the information contained in the genes found in the L and the H strands of mtDNA, and its function in the mitochondrial processes, like the mechanism of energy production that occurs inside of the mitochondria by the coupling of electron transfer and ATP synthesis or still others uses like forensic identification.