Prevalência de Listeria monocytogenes, Escherichia coli O157, Salmonella spp. e micro-organismos indicadores de contaminação em bovinos abatidos em estabelecimento de exportação

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito residual da adubação de plantio com torta de filtro e fosfato solúvel na produtividade e qualidade da cana-de-açúcar

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Atributos microbiológicos, químicos e granulométricos de organossolo e latossolos vermelhos: efeito sazonal e uso do solo

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Parâmetros microbiológicos no sistema de plantio direto e convencional em solos com diferentes teores de argila

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação do potencial de reuso agrícola do efluente de uma estação de tratamento de esgoto com alagados construídos

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Perfil metagenômico de solo sob cultivo de cana-de-açúcar com perspectiva na produção de bioenergia

Pós-graduação em Microbiologia Agropecuária - FCAV

Isolamento e seleção de micro-organismos e desenvolvimento de tecnologia para produção de ácido lático

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Microbial populations and activities of mangrove, restinga and Atlantic forest soils from Cardoso Island, Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Implantação do pinhão-manso em solo degradado inoculado e acrescido de macrófita, cinza e hidrogel

Pós-graduação em Agronomia - FEIS

Ferramenta computacional para identificação de micro-organismos com base em assinaturas genômicas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influência do manejo do solo em atributos químicos, físicos e microbiológicos dos córregos Jaboticabal e Cerradinho

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Brazilian research on extremophiles in the context of astrobiology

Extremophiles are organisms adapted to grow at extreme ranges of environmental variables, such as high or low temperatures, acid or alkaline medium, high salt concentration, high pressures and so forth. Most extremophiles are micro-organisms that belong to the Archaea and Bacteria domains, and are widely spread across the world, which include the polar regions, volcanoes, deserts, deep oceanic sediments, hydrothermal vents, hypersaline lakes, acid and alkaline water bodies, and other extreme environments considered hostile to human life. Despite the tropical climate, Brazil has a wide range of ecosystems which include some permanent or seasonally extreme environments. For example, the Cerrado is a biome with very low soil pH with high Al+3 concentration, the mangroves in the Brazilian coast are anaerobic and saline, Pantanal has thousands of alkaline-saline lakes, the Caatinga arid and hot soils and the deep sea sediments in the Brazilian ocean shelf. These environments harbour extremophilic organisms that, coupled with the high natural biodiversity in Brazil, could be explored for different purposes. However, only a few projects in Brazil intended to study the extremophiles. In the frame of astrobiology, for example, these organisms could provide important models for defining the limits of life and hypothesize about life outside Earth. Brazilian microbiologists have, however, studied the extremophilic micro-organisms inhabiting non-Brazilian environments, such as the Antarctic continent. The experience and previous results obtained from the Brazilian Antarctic Program (PROANTAR) provide important results that are directly related to astrobiology. This article is a brief synopsis of the Brazilian experience in researching extremophiles, indicating the most important results related to astrobiology and some future perspectives in this area. Received 29 February 2012, accepted 25 May 2012, first published online 11 July 2012

No adverse effect of genetically modified antifungal wheat on decomposition dynamics and the soil fauna community - a field study

The cultivation of genetically modified (GM) plants has raised several environmental concerns. One of these concerns regards non-target soil fauna organisms, which play an important role in the decomposition of organic matter and hence are largely exposed to GM plant residues. Soil fauna may be directly affected by transgene products or indirectly by pleiotropic effects such as a modified plant metabolism. Thus, ecosystem services and functioning might be affected negatively. In a litterbag experiment in the field we analysed the decomposition process and the soil fauna community involved. Therefore, we used four experimental GM wheat varieties, two with a race-specific antifungal resistance against powdery mildew (Pm3b) and two with an unspecific antifungal resistance based on the expression of chitinase and glucanase. We compared them with two non-GM isolines and six conventional cereal varieties. To elucidate the mechanisms that cause differences in plant decomposition, structural plant components (i.e. C:N ratio, lignin, cellulose, hemicellulose) were examined and soil properties, temperature and precipitation were monitored. The most frequent taxa extracted from decaying plant material were mites (Cryptostigmata, Gamasina and Uropodina), springtails (Isotomidae), annelids (Enchytraeidae) and Diptera (Cecidomyiidae larvae). Despite a single significant transgenic/month interaction for Cecidomyiidae larvae, which is probably random, we detected no impact of the GM wheat on the soil fauna community. However, soil fauna differences among conventional cereal varieties were more pronounced than between GM and non-GM wheat. While leaf residue decomposition in GM and non-GM wheat was similar, differences among conventional cereals were evident. Furthermore, sampling date and location were found to greatly influence soil fauna community and decomposition processes. The results give no indication of ecologically relevant adverse effects of antifungal GM wheat on the composition and the activity of the soil fauna community.

Rizobactérias nativas da Caatinga com potencial para redução dos efeitos da seca em soja (Glycine max L.)

No semiárido brasileiro, a vegetação predominante é a Caatinga, bioma ainda pouco explorado, que apresenta plantas e micro-organismos com alta resistência aos períodos de seca imposto pelo clima. Os micro-organismos associados às plantas deste bioma, são capazes de desenvolver mecanismos de proteção celular contra o estresse hídrico, assim como proteção vegetal contra a dessecação. O presente estudo buscou compreender as rizobactérias associadas a Mimosa artemisiana a fim de selecionar bactérias tolerantes à seca com características de promover o crescimento de plantas sob condições de estresse hídrico, diminuindo assim, os efeitos adversos impostos pela seca. As amostras de solo rizosférico foram coletadas ao longo da Caatinga, englobando os estados da BA e PE, totalizando quatro pontos de coleta. Com o uso de metodologias dependentes de cultivo, foi isolado bactérias com algumas características de promoção de crescimento de plantas diretos e/ou indiretos, como produção de AIA e fixação de nitrogênio. Além disso, linhagens capazes de crescer em meio com reduzida atividade de água e com mecanismos de proteção contra a dessecação, como, produção de EPS, biofilme, produção da ACC deaminase e indução de resistência sistêmica através das enzimas peroxidase e polifenoloxidase. Uma linhagem de Paenibacillus sp. e outra de Bacillus sp. foram capazes de promover o crescimento de soja sob condições de estresse hídrico, aumentando alguns parâmetros vegetais como, parte aérea e sistema radicular analisados.

Anaerobic and aerobic metabolism of glycogen-accumulating organisms selected with propionate as the sole carbon source

In the microbial competition observed in enhanced biological phosphorus removal (EBPR) systems, an undesirable group of micro-organisms known as glycogen-accumulating organisms (GAOs) compete for carbon in the anaerobic period with the desired polyphosphate-accumulating organisms (PAOs). Some studies have suggested that a propionate carbon source provides PAOs with a competitive advantage over GAOs in EBPR systems; however, the metabolism of GAOs with this carbon source has not been previously investigated. In this study, GAOs were enriched in a laboratory-scale bioreactor with propionate as the sole carbon source, in an effort to better understand their biochemical processes. Based on comprehensive solid-, liquid- and gas-phase chemical analytical data from the bioreactor, a metabolic model was proposed for the metabolism of propionate by GAOs. The model adequately described the anaerobic stoichiometry observed through chemical analysis, and can be a valuable tool for further investigation of the competition between PAOs and GAOs, and for the optimization of the EBPR process. A group of Alphaproteobacteria dominated the biomass (96% of Bacteria) from this bioreactor, while post-fluorescence in situ hybridization (FISH) chemical staining confirmed that these Alphaproteobacteria produced poly-beta-hydroxyalkanoates (PHAs) anaerobically and utilized them aerobically, demonstrating that they were putative GAOs. Some of the Alphaproteobacteria were related to Defluvicoccus vanus (16% of Bacteria), but the specific identity of many could not be determined by FISH. Further investigation into the identity of other GAOs is necessary.