Resumo: O propósito deste estudo é investigar a biodegradação de filmes de PHB, PP e blenda de PP/PHB (1:1) por microrganismos de águas de rio poluído que recebeu vários tipos de descartes, inclusive de refinaria de petróleo. Os filmes poliméricos foram obtidos por fusão do pó do material a 175 °C, prensados a 71,3 kgf.cm -2 e resfriados a 25 °C. Estes filmes foram mantidos em amostras de águas do rio poluído, coletadas antes e após o descarte do efluente da refinaria de petróleo e mantidas em estufa bacteriológica a 28 °C, durante 120 dias. As mudanças, causadas pela ação microbiana nos filmes, foram analisadas por medidas de perda de massa, infravermelho com transformada de Fourier (FTIR) e microscopia eletrônica de varredura (MEV). Os resultados provaram que a degradação do PHB ocorre tanto na sua fase amorfa como na cristalina, sendo mais significativa na água do rio que recebeu o efluente da refinaria de petróleo, contendo microrganismos reconhecidos como potencialmente capazes de degradar substâncias persistentes no meio ambiente. Palavras-chave: Biodegradação, PP, PHB, blendas, microrganismos, rio poluído. Biodegradation of Polypropylene (PP), Poly(3-hydroxybutyrate) (PHB) Films and PP/PHB Blend by Microorganisms from Atibaia RiverAbstract: The purpose of this study is to investigate the biodegradation of films made with PP, PHB and PP/PHB (1:1) blend caused by microorganisms from polluted river which received several types of waste, including an oil refinery effluent. The films were obtained by melting the powder from the material at 175 °C, pressed at 71.3 kgf.cm -2 and cooled at 25 °C. These films were kept in polluted river water samples, collected before and after the discarding of oil refinery waste, and they were kept in the bacteriological incubator at 28 °C for 120 days. The changes caused by microbial action on the films were analyzed by measurements of weight loss, Fourier transform infrared (FTIR) and scanning electronic microscopy (SEM). The results proved that PHB degradation occurs in amorphous and crystalline phases, being more significant in the river water which received refinery oil waste, containing microorganisms recognized as potentially capable to degrade recalcitrant substances in the environment. Keywords: Biodegradation, PP, PHB, blends, microorganisms, polluted river. IntroduçãoOs polímeros sintéticos tornaram-se importantes na sociedade porque podem substituir materiais como: papel, madeira, vidro e metal, solucionando grande número de problemas, quer na indústria, na agricultura, na medicina e em outras áreas. Isso se deve às características como: durabilidade, atoxicidade, baixo custo, facilidade para serem moldados, capacidade de serem reciclados e versatilidade de aplicação. O mercado de resinas plásticas tem aumentado ultimamente, significando uma expansão da indústria petroquímica, que movimenta a economia e gera empregos em diversos segmentos do setor [1,2] . Entretanto, o uso e o descarte indevidos dos materiais plásticos, aliados a sua resistência à degradação acabam g...

The present study performed an analysis about the effects of andiroba seed oil (Carapa guianensis) in the ovary of Rhipicephalus sanguineus semi-engorged females; once, there are few studies about the action of natural products on the reproductive system, a vital organ for the biological success of this animal group. The results showed that andiroba oil is a potent natural agent which causes significant structural changes in the oocytes, such as the emergence of large vacuolated cytoplasmic regions, reduction in the number of yolk granules, changes in the shape of the cells, as well as impairment of genetic material. In addition, the ovary epithelium showed severe morphological changes, such as extreme structural disorganization, with highly vacuolated cells and picnotic nuclei, forming an amorphous mass. This study showed also that oocytes (mainly in the initial stages of development) and the ovary epithelium of R. sanguineus females subjected to different concentrations of andiroba oil presented morphological changes which became more numerous and intense as the concentration of the product increased. Based on the results, it can be inferred that although the defense mechanisms are developed by oocytes to recover the cellular integrity (presence of autophagic vacuoles), these cells are not able to revert the damage caused by this product. Thus, it can be concluded that although the damages caused to the oocytes by andiroba oil are comparatively less severe than the ones caused by synthetic acaricides, this product can be considered a potent natural agent that reduce and/or prevent the reproduction of R. sanguineus females, with the advantage of not causing environmental impact such as synthetic chemical acaricides.

Because of the increasing medical-veterinary importance of ticks, the development of alternative control methods, less aggressive to the host and the environment has become the target of several researches. In this sense, the present study analyzed the action of different concentrations (5, 10, and 20%) of andiroba seed oil (Carapa guianensis) on the reproductive system of Rhipicephalus sanguineus females, through histochemical techniques and the quantification of the reproductive efficiency index. The results showed that andiroba oil is a potent natural agent, able to cause several changes in the oocytes of this species, impairing the reproductive success, once this natural product induces great physiological changes in the oocytes in all development stages, such as drastic reduction in proteins, polysaccharides, and lipids in these cells, and these components are essential for the viability of the embryo. In addition, it was observed that this product stimulate the oviposition, mainly at the concentration of 20%. This higher production of eggs represents a defense mechanism developed by the organism in order to ensure the reproductive success of the species, even in the presence of the toxic agent. However, the results obtained suggested that the laid eggs would not be viable, due to the great changes undergone by the oocytes. Thus, the present study showed that the use of this vegetal product would be an alternative way to control the ticks, bringing benefits similar to the ones obtained through the use of synthetic acaricides; however, with less damage to nontarget organisms and the environment as well.

Actually, the most used method to control ticks is synthetic acaricides with neurotoxic action. However, the use of these methods presents inconveniences, such as the contamination of the environment and risks to the host's health due to the residual effects. Thus, several studies have been developed aiming to find alternative ways to control these ectoparasites, such as the use of natural compounds with active ingredients, which act controlling some species of plagues in addition to presenting medicinal properties that are beneficial to humans. The present study aimed to analyze the action of andiroba oil (Carapa guianensis) on the synganglion of Rhipicephalus sanguineus semiengorged females through morphological and cytochemical techniques aiming to verify if this natural product have neurotoxic action as the numerous synthetic acaricides. The results showed that andiroba oil interferes in the synganglion through structural and enzymatic changes, which lead the nervous tissue to apoptotic death involving autophagy. Among these changes was observed the emergence of large empty spaces between the perineurium and the cortical region, vacuolated cortex cells and with cell swelling, neural cells with picnotic nuclei or in initial stage of chromatin margination and neuropile with high structural disorganization. Considering these data, it can be concluded that andiroba seed oil can be used as an alternative method in the control of R. sanguineus ticks due to its neurotoxic action.

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SbstractThere is considerable concern about the impact plastic materials have on the environment due to their durability and resistance to degradation. The use of pro-oxidant additives in the polymer films could be a viable way to decrease the harmful effects of these discarded materials. In this study, films of PHBV/PP-co-PE (80/20 w/w) and PHBV/PP-co-PE/add (80/19/1 w/w/w) (with pro-oxidant additive) were employed to verify the influence of the additive on the biodegradation of these films in the soil. These films were obtained by melting the pellets in a press at 180 °C which were buried in soil columns for 3 and 6 months. Some samples were also heated before being buried in soil. The biodegradation is higher for the additive blend buried for 3 months than for the pre-heated blend. After 6 months the blend buried and heated/buried was completely degraded in soil. The effect of the additive, on chain oxidation, is more time-dependant than heat-dependant.