Summary Co‐infection by vector‐borne plant viruses is common, yet few studies have explored the effects of mixed infections on host‐plant phenotypes or plant–vector interactions. We documented the effects of single and mixed infection by Bean pod mottle virus (BPMV) and Soybean mosaic virus (SMV) on key biochemical plant traits and the behaviour and performance of virus vectors (BPMV: Epilachna varivestis, SMV: Aphis glycines) in order to understand how virus‐induced changes in plant phenotypes might influence (i) the acquisition and transmission of each virus by its respective vector in single infections, (ii) the likelihood of secondary infection for plants singly infected with either virus and (iii) the implications of co‐infection for virus transmission by vectors. Single infection by either BPMV or SMV increased host‐plant palatability for E. varivestis, potentially enhancing vector acquisition of BPMV from BPMV‐infected plants as well as the risk of secondary BPMV infection in plants infected with SMV. However, co‐infected plants were no more palatable to beetle vectors than mock‐inoculated plants. BPMV infection had minimal impacts on A. glycines. SMV infection reduced A. glycines population growth, but increased aphid feeding preferences for infected plants, a pattern likely not conducive to the (non‐persistent) transmission of SMV. Co‐infection eliminated the negative effects of single SMV infection on aphid population growth, and aphids exhibited a feeding preference for co‐infected (relative to mock‐inoculated) plants. Our results demonstrate that virus effects on host phenotype and vector behaviour can be modified by the presence of a co‐infecting virus, with potentially important implications for disease transmission.

Xylanase and α-amylase enzymes participate in the degradation of organic matter, acting in hemicellulose and starch mineralization, respectively, and are in high demand for industrial use. Mangroves represent a promising source for bioprospecting enzymes due to their unique characteristics, such as fluctuations in oxic/anoxic conditions and salinity. In this context, the present work aimed to bioprospect xylanases from mangrove soil using cultivation-dependent and cultivation-independent methods. Through screening from a metagenomic library, three potentially xylanolytic clones were obtained and sequenced, and reads were assembled into contigs and annotated. The contig MgrBr135 was affiliated with the Planctomycetaceae family and was one of 30 ORFs selected for subcloning that demonstrated only amylase activity. Through the cultivation method, 38 bacterial isolates with xylanolytic activity were isolated. Isolate 11 showed an enzymatic index of 10.9 using the plate assay method. Isolate 39 achieved an enzyme activity of 0.43 U/mL using the colorimetric method with 3,5-dinitrosalicylic acid. Isolate 39 produced xylanase on culture medium with salinity ranging from 1.25 to 5%. Partial 16S rRNA gene sequencing identified isolates in the Bacillus and Paenibacillus genera. The results of this study highlight the importance of mangroves as an enzyme source and show that bacterial groups can be used for starch and hemicellulose degradation.

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Aos meus pais Janete e Evanir, minha irmã Natália por serem a minha base, os meus exemplos, pelo amor e apoio incondicionais durante toda a minha vida e trajetória acadêmica. Á minha família em especial aos meus avós: José, Benedita e Laurita (in memorian), pelo exemplo de simplicidade, inteligência e por todo o afeto. Ao Deived, meu amor e companheiro, pelo convívio, pelo amor, incentivo e apoio diário em todos os momentos. As minhas amigas Cris, Mayra (Vents), Dayane e Dani pela amizade, pelo apoio e pela força. Obrigada!

Comunidades de arquéias metanogênicas omunidades de arquéias metanogênicas omunidades de arquéias metanogênicas omunidades de arquéias metanogênicas em diferentes usos dos solos d em diferentes usos dos solos d em diferentes usos dos solos d em diferentes usos dos solos da Amazônia a Amazônia a Amazônia a Amazônia versão revisada de acordo com a resolução CoPGr 6018 de 2011