The purpose of the present study was to evaluate the antimicrobial potential of styrene-ethylene/ butylene-styrene based thermoplastic elastomers (TPE) incorporated with zinc pyrithione (ZnPT) and silver nanoparticles (AgNano). Japan Industrial Standard was applied to evaluate the antimicrobial potential of incorporated TPE compounds against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Antifungal action was evaluated against Aspergillus niger, Candida albicans and Cladosporium cladosporioides. Samples prepared with ZnPT eliminated 99.9% of the E. coli and 99.7 % of the S. aureus population, and presented an inhibition zone in the fungal assay. Samples prepared with AgNano eliminated 99.7% of the E. coli and 95.5 % of the S. aureus population. There was no inhibition zone in samples containing AgNano; however, these samples did not present fungal growth on their surfaces. TPE samples containing ZnPT showed biocidal activity against the microorganisms tested and can be used to develop antimicrobial products.

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In agricultural systems, interactions between plants and microorganisms are important to maintaining production and profitability. In this study, bacterial communities in floodwaters of rice fields were monitored during the vegetative and reproductive stages of rice plant development using 16S amplicon sequencing. The study was conducted in the south of Brazil, during the crop years 2011/12 and 2012/13. Comparative analyses showed strong differences between the communities of floodwaters associated with the two developmental stages. During the vegetative stage, 1551 operational taxonomic units (OTUs) were detected, while less than half that number (603) were identified in the reproductive stage. The higher bacterial richness observed in floodwater collected during the vegetative stage may have been favored by the higher concentration of nutrients, such as potassium, due to rhizodeposition and fertilizer application. Eighteen bacterial phyla were identified in both samples. Both communities were dominated by Gammaproteobacteria. In the vegetative stage, Alphaproteobacteria and Betaproteobacteria were more abundant and, in contrast, Bacilli and Clostridia were the more dominant classes in the reproductive stage. The major bacterial taxa identified have been previously identified as important colonizers of rice fields. The richness and composition of bacterial communities over cultivation time may contribute to the sustainability of the crop.

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Health concerns have driven the production of antimicrobial materials aimed at controlling the spread of diseases. Styrene-ethylene/butylene-styrene (SEBS)-based thermoplastic elastomers (TPE) incorporated with titanium dioxide (TiO 2 ), magnesium hydroxide (Mg(OH) 2 ) and aluminium hydroxide (Al(OH) 3 ) are one way to produce antimicrobial polymers. The purpose of this study is to characterise SEBS-based TPE compounds incorporated with TiO 2 , Mg(OH) 2 and Al(OH) 3 . The mechanical, optical and antimicrobial characteristics of TPE samples were investigated. The differences between the means in the mechanical properties of all loaded materials were not significant. The optical results show a reduction in polymer transparency, with total opacity after the incorporation of TiO 2 . Among the additives tested, TiO 2 offered the best antimicrobial action. There was no fungal growth on the loaded TPE surface. The incorporation of TiO 2 in SEBS-based TPE materials may be used in the industry to develop antimicrobial products, which, when complemented with additional disinfection treatments, can contribute to public health.

Styrene-butylene/ethylene-styrene-based thermoplastic elastomers (TPE) are polymers with soft touch properties that are widely used for manufacturing devices that involve hand contact. However, when contaminated with microorganisms these products can contribute to spreading diseases. The incorporation of antibacterial additives can help maintain low bacteria counts. This work evaluated the antibacterial action of TPE loaded with silver ions and silver nanoparticles. The additives nanosilver on fumed silica (NpAg_silica), silver phosphate glass (Ag 1 _phosphate), and bentonite organomodified with silver (Ag 1 _bentonite) were added to the TPE formulation. The compounds were evaluated for tensile and thermal properties and antimicrobial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). All the additives eliminated over 90% of E. coli, but only NpAg_silica killed more than 80% of S. aureus population. The better effect of NpAg_silica was attributed to the additive's high specific surface area, which promoted greater contact with bacteria cells.