Bacillus megaterium: bacteria endofítica de callos de Ilex paraguariensis con actividad de promoción del crecimiento

Los microorganismos endófitos viven dentro de plantas sanas y su aislamiento e identificación pueden favorecer las aplicaciones biotecnológicas. Los microorganismos endofíticos fueron encontrados en callos de Ilex paraguariensis cultivados in vitro durante cinco meses. Se usó la secuenciación de la región 16S rRNA para identificar dos aislados como Bacillus megaterium. La presencia de células bacterianas en los espacios intercelulares de los cultivos de callos se detectó mediante análisis ultraestructurales. Los aislamientos también se evaluaron para la producción de ácido indol acético (AIA) y su potencial en la promoción del crecimiento de las plántulas de Phaseolus vulgaris L. La síntesis de ácido AIA en presencia y ausencia de L-triptófano se detectó por análisis colorimétrico para ambos aislamientos. En presencia de extractos de las cepas IPC06 e IPC07, las plántulas de P. vulgaris crecieron más rápido en comparación con las plantas control sin el extracto en pruebas in vitro.Palabras clave: yerba mate, 16S rRNA, secuenciación, cultivo de tejido

PREVENÇÃO DA CÁRIE EM ESCOLARES ATRAVÉS DE TESTES DE AVALIAÇÃO AO RISCO BIOLÓGICO DE DESENVOLVIMENTO DA DOENÇA

A ação visa identificar as condições de saúde bucal dos escolares da Rede de Ensino de Campo Largo e Região Metropolitana de Curitiba por meio de anamnese, exame clínico, avaliação de determinantes sócio-econômicas e análise de risco à cárie dental a partir da incidência de Streptococcus mutans, fornecendo dados biológicos para o controle da doença. Estudos realizados demonstraram que grupos de indivíduos com alta contagem de S. mutans na saliva apresentam significativamente maior atividade de cárie. Múltiplos testes de avaliação do risco biológico ao desenvolvimento da cárie têm sido descritos (Brathall & Carlson, 1988) com a finalidade de prever uma susceptibilidade individual identificando indivíduos que precisam de medidas específicas de prevenção, ou ainda, reduzir a velocidade de progressão da doença. O número de S. mutans na saliva é diretamente proporcional à manifestação clínica da doença. Além disso, existem biosorotipos da bactéria circulando na população, sendo assim, a investigação microbiológica através da identificação das colônias de S. mutans permite uma análise quantitativa e qualitativa do agente etiológico em cada individuo e ainda, estudos de variabilidade e distribuição dos diversos biosorotipos isolados. A prevenção baseada no risco biológico é possível e de fundamental importância

Black Fungi and Hydrocarbons: An Environmental Survey for Alkylbenzene Assimilation

Environmental pollution with alkylbenzene hydrocarbons such as toluene is a recurring phenomenon. Their toxicity and harmful effect on people and the environment drive the search for sustainable removal techniques such as bioremediation, which is based on the microbial metabolism of xenobiotic compounds. Melanized fungi present extremophilic characteristics, which allow their survival in inhospitable habitats such as those contaminated with hydrocarbons. Screening methodologies for testing the microbial assimilation of volatile organic compounds (VOC) are scarce despite their importance for the bioremediation of hydrocarbon associated areas. In this study, 200 strains of melanized fungi were isolated from four different hydrocarbon-related environments by using selective methods, and their biodiversity was assessed by molecular and ecological analyses. Seventeen genera and 27 species from three main orders, namely Chaetothyriales, Cladosporiales, and Pleosporales, were identified. The ecological analysis showed a particular species distribution according to their original substrate. The isolated strains were also screened for their toluene assimilation potential using a simple and inexpensive methodology based on miniaturized incubations under controlled atmospheres. The biomass produced by the 200 strains with toluene as the sole carbon source was compared against positive and negative controls, with glucose and with only mineral medium, respectively. Nineteen strains were selected as the most promising for further investigation on the biodegradation of alkylbenzenes.info:eu-repo/semantics/publishedVersio

CARACTERIZAÇÃO BIOQUÍMICA E MOLECULAR DE FUNGOS MELANIZADOS OBTIDOS DE AMBIENTES POLUÍDOS POR HIDROCARBONETOS MONOAROMÁTICOS

A natureza oligotrófica de fungos melanizados indicam que são capazes decrescer em ambientes inóspitos e com escassez de nutrientes. O objetivo dapesquisa foi caracterizar por análise bioquímica e molecular fungosmelanizados obtidos de áreas e materiais poluídos por hidrocarbonetos(oficinas mecânicas: materiais utilizados e ambiente). Foram obtidos 22isolados, destes 72,72% foram pela técnica de flotação em óleo mineral. Amaioria dos isolados apresentou oligotrofismo crescendo em concentraçõeselevadas de NaCl (0,0%, 2,5%, 5,0% e 10%), ampla faixa de pH (4-9) etemperatura (25ºC, 28ºC, 30ºC, 35ºC e 37ºC). Dos isolados, 15 apresentaramíndice de emulsificação em 24h (E24) e 91% apresentou caráter hidrofóbico.A atividade enzimática de lacase foi detectada em 54,54% dos isolados.Todos os isolados apresentaram crescimento nos ensaios com BTX e tambémem óleo diesel e gasolina. Seis isolados foram selecionados, com base nomaior potencial de degradação de hidrocarbonetos, para identificaçãomolecular e análise filogenética. Foram identificados como Cladosporium sp.Cla-dosporium halotolerans, Família Cladosporiaceae e Exophiala sp. eExophiala dermatitidis, Família Herpotrichiellaceae. Face ao potencialdemonstrado, verificou-se que os isolados de fungos melanizados obtidos deambientes poluídos por hidrocarbonetos suportam condições adversas decrescimento. Em adição, eles podem ser utilizados na biorremediaçãodessesambientes.Palavras-chave: Fisiologia. Biomassa. Hidrocarbonetos monoaromático

Shifts in taxonomic and functional microbial diversity with agriculture: How fragile is the Brazilian Cerrado?

Rarefaction curves generated with the MG-RAST software against M5NR database using normalized values between 0 and 1 for no-tillage (NT), conventional tillage (CT) and undisturbed Cerrado (Native) soil metagenomes. Figure S2. Sequence abundance orders of Betaproteobacteria compared to M5NR database using normalized values between 0 and 1 for no-tillage (NT), conventional tillage (CT) and undisturbed Cerrado (Native) soil metagenomes. The order Burkholderiales was the most abundant in the NT system, followed by Nitrosomonadales, both in CT and NT (p < 0.05). Figure S3. Sequence abundance of phyla of Archaea Domain compared to M5NR database, and using normalized values between 0 and 1 for no-tillage (NT), conventional tillage (CT) and undisturbed Cerrado (Native) soil metagenomes. Crenarchaeota was higher in the NT, while Thaumarchaeota and unclassified were higher in the NT and CT treatments (p < 0.05). Figure S4. Sequence abundance of the phyla of Eukaryota Domain compared to M5NR database and using normalized values between 0 and 1 for no-tillage (NT), conventional tillage (CT) and undisturbed Cerrado (Native) soil metagenomes. Figure S5. Sequence abundance in the Viruses domain compared to M5NR database using normalized values between 0 and 1 for no-tillage (NT), conventional tillage (CT) and undisturbed (Native) soil metagenomes. Caudovirales was higher in the NT and CT systems (p < 0.05). (DOCX 423 kb

Vaccuuming method as a successful strategy in the diagnosis of active infestation by Pediculus humanus capitis

Most human epidemiological and clinical studies use visual inspection of the hair and scalp to diagnose Pediculus humanus capitis, however this method has low sensitivity to diagnose active infestations (presence of nymphs and adult lice). Vacuuming the hair and scalp has been used as a diagnostic method, but there are no previous data comparing its effectiveness with visual inspection. The aim of this study was to determine the prevalence of overall infestation (nits and trophic stages), of active infestation by Pediculus humanus capitis, and to evaluate the effectiveness of vacuuming in comparison with the visual inspection. Visual inspection was performed by three examiners and vacuuming of the scalp by one investigator, with an adapted vacuum cleaner. A total of 166 children aged 4 to 10 years old were randomly selected from public schools in Southern Brazil. Considering the positive results obtained by both methods, the prevalence of overall infestation was 63.3%, whereas active infestation was 18.7%. The visual inspection was more effective on diagnosing overall infestation, however, its effectiveness to detect active infestation was lower, ranging from 0.6% (RR=3%, p<0.001) to 6.6% (RR=35%, p=0.001), depending on the number of examiners. The effectiveness of vacuuming to diagnose active infestation was higher than the one of visual inspection, with a prevalence rate of 16.3% (RR=87%, p=0.332). As presented in our study, the vacuuming method was 2.74 to 7.87 times most likely to detect active infestation, thus it could be adopted as a more accurate method to diagnose active pediculosis