Biocides used as additives to biodiesels and their risks to the environment and public health : a review

One of the advantages of using biodiesel and its blends with diesel oil is the lower levels of emissions of particulate matter, sulfur dioxide, carbon monoxide, among others, making it less harmful to the environment and to humans. However, this biofuel is susceptible to microbial contamination and biodeterioration. In this sense, studies on the use of effective low toxicity biocides are being carried out, and this work aims to present the latest information (2008–2018) available in the scientific databases, on the use of biocides in biodiesel, mainly concerning their toxicity to the environment and public health. The results showed that in relation to the control of microbial contamination, the current scenario is limited, with seven publications, in which the most studied additives were isothiazolinones, oxazolidines, thiocyanates, morpholines, oxaborinanes, thiocarbamates and phenolic antioxidants. Studies regarding direct experiments with humans have not been found, showing the need for more studies in this area, since the potential growth of biodiesel production and consumption in the world is evident. Thus, there are need for more studies on antimicrobial products for use in biodiesel, with good broad-spectrum activity (bactericidal and fungicidal), and further toxicological tests to ensure no or little impact on the environment

Bean tissue culture for introduction of foreign genes

O objetivo deste trabalho foi determinar parâmetros da cultura de tecidos de feijoeiro necessários para a aplicação da técnica de transformação via Agrobacterium. Diversos genótipos de feijoeiro (Phaseolus vulgaris L.) foram cultivados in vitro. Alguns parâmetros visando à infecção de ápices caulinares com Agrobacterium tumefaciens foram otimizados, como a eliminação da agrobactéria após a co-cultura e a concentração de kanamicina suficiente para a seleção dos ápices infectados. Multibrotações em nós cotiledonares foram obtidas com freqüência de até 55,7%, dependendo do genótipo utilizado. Estes nós foram infectados com A. tumefaciens contendo em seu plasmídeo Ti o gene da β-glucuronidase (GUS) sob regulação de promotor eucariótico. Entre as multibrotações obtidas, 30% apresentaram região onde foi detectada atividade do gene GUS. Demonstrou-se também a susceptibilidade de feijoeiro a Agrobacterium rhizogenes. Raízes transgênicas foram obtidas após infecção de epicótilos.The objective of this work was to determine different bean tissue culture parameters necessary to the application of Agrobacterium-mediated transformation technique. Several bean (Phaseolus vulgaris L.) genotypes were cultured in vitro. The protocols for Agrobacterium elimination, after infection of the apical meristems with Agrobacterium tumefaciens and the selective kanamycin concentration were determined. Depending on the genotype, multiple buds were obtained from cotiledonary nodes in a frequency up to 55.7%. The cotiledonary nodes were infected with A. tumefaciens carrying in the Ti plasmid the gene for β-glucuronidase (GUS) under the control of an eucariotic promoter. Regions with GUS activity were detected in 30% of the shoots. The susceptibility of bean to Agrobacterium rhizogenes was also shown. Transgenic roots were obtained after infection of epicotyls with A. rhizogenes

Seasonal variations in soil microbiota profile of termite (Syntermes wheeleri) mounds in the Brazilian tropical savanna

Eusocial animals, such as the termites, often build a nest-like structure called a mound that provides shelter with stable internal conditions and protection against predators. Termites are important components of the Brazilian Cerrado biota. This study aimed to investigate the bacterial community composition and diversity of the Syntermes wheeleri termite-mound soil using culture-independent approaches. We considered the vertical profile by comparing two different mound depths (mound surface and 60 cm) and seasonality with samplings during the rainy and dry seasons. We compared the mound soil microbiota to the adjacent soil without the influence of the mound to test the hypothesis that the Cerrado soil bacterial community was more diverse and more susceptible to seasonality than the mound soil microbiota. The results support the hypothesis that the Cerrado soil bacterial community is more diverse than the mound soil and also has a higher variability among seasons. The number of observed OTUs (Operational Taxonomic Units) was used to express bacterial richness, and it indicates that soil moisture has an effect on the community distribution and richness of the Cerrado samples in comparison to mound samples, which remain stable across seasons. This could be a consequence of the protective role of the mound for the termite colony. The overall community taxonomic profile was similar between soil samples, especially when compared to the taxonomic composition of the Syntermes wheeleri termite’s gut, which might be explained by the different characteristics and functionality between the soil and the gut microbial community

Controlo integrado da Lagarta das Pastagens Mythimna unipuncta (Haworth)

II Jornadas Agronómicas Açorianas, Outubro, 1991, Ponta Delgada, Açores.No Arquipélago dos Açores, desde 1970 e com maior incidência na ilha de S. Miguel, devido ao aumento da área de pastagem, com vista ao desenvolvimento da bovinocultura, uma das espécies de Noctuídeos, Mythimna unipuncta (Haworth) (Lepidoptera, Noctuidae), assinalada na região desde 1810 por GODMAN, tornou-se num grave problema económico, estimando-se os seus prejuízos em cerça de 8% da produção anual das pastagens (TAVARES, 1989)

Pairwise post-hoc comparisons (Games-Howell) and mean bacterial density (CFU/mL) of the amphibian species.

<p>Mean density values are Box-Cox transformation.</p

Total number of individuals of amphibians sampled, listed by species and sampling site.

<p>Total number of individuals of amphibians sampled, listed by species and sampling site.</p

Composition of bacterial species isolated from the skin of four anuran species and their occurrence.

<p>Composition of bacterial species isolated from the skin of four anuran species and their occurrence.</p

Photos illustrating the forest types studied.

<p>(A) Continuous forest of Atlantic Forest; (B) Fragmented forest of Atlantic Forest.</p

Possible associations between bovine growth hormone gene polymorphism and reproductive traits

The polymorphism of the bovine growth hormone gene (bGH) was studied in 211 Nellore pure breed males for association with reproductive traits. Scrotal circumference and testosterone concentrations were collected monthly from 10 until 16 months of age. Additionally, testicular growth rates were calculated. DNA was amplified by PCR and digested using Msp I and Hae III restriction enzymes. Every polymorphism presented two alleles. The predominant alleles were D (0.85) and F (0.98), respectively, and genotype EE – bGH/Hae III was missing. Significant association (P<0.05) between bGH/Msp I polymorphism, scrotal circumference and testicular growth after puberty, as well as between bGH/Hae III and testosterone concentrations at puberty were detected. The results suggested that these association could be useful for selection, since bGH/Msp I and bGH/Hae III polymorphisms could be considered as markers for testicular development after puberty and onset of puberty, respectively