Draft Genome Sequence of the Wild Edible Mushroom Pleurotus ostreatoroseus DPUA 1720.

The draft whole-genome sequence of the mushroom Pleurotus ostreatoroseus DPUA 1720 (38,588,587 bp) is presented here. This report contributes to the prospective research for bioactive compounds in the genus Pleurotus.

Colletotrichum siamense, a Mycovirus-Carrying Endophyte, as a Biological Control Strategy for Anthracnose in Guarana Plants

Abstract Guarana, the fruit of Paullinia cupana, is known for its stimulating and medicinal properties by the Amazonian indigenous population and communities. However, it presents serious phytopathological problems, such as anthracnose disease caused by Colletotrichum spp. The objective of this study was to verify if C. siamense, a mycovirus-carrying endophytic fungus, could protect guarana seedlings, by reducing or by eliminating characteristic disease symptoms. Other physiological changes in the plant caused by the presence of this endophyte were also evaluated. The cuttings of the Cereçaporanga cultivar were dipped in a biological control suspension and planted in a specific substrate. After four months in the greenhouse, the seedlings were sprayed with a suspension of phytopathogen conidia, and a portion of these seedlings received the fungicide indicated for the crop to be compared with the control seedlings. After 28 days, the number of lesions, morphophysiological and macro characteristics, and leaf micronutrients were evaluated. The seedlings treated with C. siamense showed a lower percentage of lesions and an increased aerial part and root system compared to the other treatments. There were no significant differences between treatments regarding the percentage of macronutrients and micronutrients.

Bacterial communities associated with anthracnose symptomatic and asymptomatic leaves of guarana, an endogenous tropical crop, and their pathogen antagonistic effects.

Plants are colonized by diverse microorganisms that can substantially impact their health and growth. Understanding bacterial diversity and the relationships between bacteria and phytopathogens may be key to finding effective biocontrol agents. We evaluated the bacterial community associated with anthracnose symptomatic and asymptomatic leaves of guarana, a typical tropical crop. Bacterial communities were assessed through culture-independent techniques based on extensive 16S rRNA sequencing, and cultured bacterial strains were evaluated for their ability to inhibit the growth of Colletotrichum sp. as well as for enzyme and siderophore production. The culture-independent method revealed that Proteobacteria was the most abundant phylum, but many sequences were unclassified. The emergence of anthracnose disease did not significantly affect the bacterial community, but the abundance of the genera Acinetobacter, Pseudomonas and Klebsiella were significantly higher in the symptomatic leaves. In vitro growth of Colletotrichum sp. was inhibited by 11.38% of the cultured bacterial strains, and bacteria with the highest inhibition rates were isolated from symptomatic leaves, while asymptomatic leaves hosted significantly more bacteria that produced amylase and polygalacturonase. The bacterial isolate Bacillus sp. EpD2-5 demonstrated the highest inhibition rate against Colletotrichum sp., whereas the isolates EpD2-12 and FD5-12 from the same genus also had high inhibition rates. These isolates were also able to produce several hydrolytic enzymes and siderophores, indicating that they may be good candidates for the biocontrol of anthracnose. Our work demonstrated the importance of using a polyphasic approach to study microbial communities from plant diseases, and future work should focus on elucidating the roles of culture-independent bacterial communities in guarana anthracnose disease.

Potential of Bacterial Isolates from a Stream in Manaus-Amazon to Bioremediate Chromium-Contaminated Environments.

Igarapé do Quarenta (IgQ), a stream located in the Manaus-AM, BR, has directly experienced the impacts of urban expansion over the last five decades, which contributed for its contamination. As an affluent of Rio Negro, IgQ also affects the water quality of this important river that bathes Manaus. However, the stress caused by the prolonged exposition to chemical agents may have selected microorganisms that exhibit great bioremediation potential. In the present study, bacteria isolated from four distinct sites of the IgQ were identified, and their potential to degrade hexavalent chromium (Cr(VI)) was investigated using the s-diphenylcarbazide method. Among the investigated isolates, 14 exhibited resistance against Cr(VI) at a concentration of 300 mg/L and eight isolates reduced over 50% (53.5-97.4%) chromium ratios after 72 h of incubation. Those isolates were identified by gene sequencing and classified in 10 genera (Acidovorax sp., Acinetobacter sp., Alicycliphilus sp., Bacillus sp., Comamonas sp., Enterobacter sp., Micrococcus sp., Proteus sp., Serratia sp., and Vagococcus sp.). Under control conditions, the isolate of Vagococcus sp. genus, in only 24 h of incubation, reduced 96.8% of the rate of Cr(VI) added to the culture medium at the concentration of 10 mg/L. Obtained results indicate that the Vagococcus sp. exhibits a great potential to be used in the bioremediation of areas contaminated with chromium. The mechanisms of action of microorganisms should be investigated for more specific applications in the decontamination of effluents and direct use of its by-products to bioremediate polluted environments.

Assessment of petroleum biodegradation for Bacillus toyonensis by the using redox indicator 2,6 dichlorophenol indophenol / Avaliação da biodegradação do petróleo por Bacillus toyonensis, usando o indicador redox 2,6 diclorofenol indofenol

Petroleum degrading microorganisms have been isolated from different environments with the purpose of being used in bioremediation processes in areas impacted by petroleum spills. The objective of this study was to evaluate the ability of Bacillus toyonensis AM07 strain to metabolize petroleum compounds. The strain was isolated from the effluent dike of the Urucu Petroleum Province, Coari - Amazonas, Brazil. The degrading activity of B. toyonensis was evaluated by the colorimetric method using the redox indicator 2,6-dichlorophenol indophenol (DCPIP). Thus, the microorganism was inoculated into minimal medium with DCPIP, and with petroleum as the sole carbon source. The degradation potential of the microorganism was found by changing the DCPIP staining and absorbance readings 600nm. The results obtained demonstrated that the bacterial strain was able to degrade petroleum by altering the color of the medium from blue to colorless and by reducing the concentration of the indicator in the absorbance readings. B. toyonensis AM07 strain has shown good performance in the petroleum degradation assays and may be used in the future in remediation technologies for hydrocarbon impacted environments.

Microrganismos degradadores de petróleo têm sido isolados de diferentes ambientes com a finalidade de serem utilizados em processos de biorremediação de áreas impactadas com derrames de petróleo. O objetivo deste estudo foi avaliar a capacidade da linhagem de Bacillus toyonensis AM07, isolada do dique de efluente da Província Petrolífera de Urucu, Coari - Amazonas, Brasil, em metabolizar compostos do petróleo. A atividade degradadora do B. toyonensis foi avaliada pelo método colorimétrico, utilizando indicador redox 2,6-diclorofenol indofenol (DCPIP). Assim, o microrganismo foi inoculado em meio mínimo com DCPIP e petróleo como única fonte de carbono. O potencial de degradação do microrganismo foi constatado mediante a mudança de coloração DCPIP e leituras de absorbância 600nm. Os resultados obtidos demonstraram que a cepa bacteriana foi capaz de degradar petróleo, alterando a coloração do meio de azul para incolor e reduzindo a concentração do indicador nas leituras de absorbâncias. A cepa de B. toyonensis AM07 mostrou bom desempenho nos ensaios de degradação do petróleo, podendo ser utilizada, no futuro, em tecnologias de remediação de ambientes impactados por hidrocarbonetos.

Screening of tropically derived, multi-trait plant growth- promoting rhizobacteria and evaluation of corn and soybean colonization ability.

The present study assessed the plant growth-promoting (PGP) traits and diversity of culturable rhizobacteria associated with guarana (Paullinia cupana), a typical tropical plant. Ninety-six bacteria were isolated, subjected to biochemical tests, and identified by partial or total 16S rDNA sequencing. Proteobacteria and Firmicutes were the dominant rhizospheric phyla found, and Burkholderia and Bacillus were the most abundant genera. Thirteen strains exhibited the four PGP traits evaluated, and most of them belonged to the genus Burkholderia. Two multi-trait PGP strains, RZ2MS9 (Bacillus sp.) and RZ2MS16 (Burkholderia ambifaria), expressively promoted corn and soybean growth under greenhouse conditions. Compared to the non-inoculated control, increases in corn root dry weight of 247.8 and 136.9% were obtained with RZ2MS9 and RZ2MS16 inoculation, respectively, at 60days after seeding. The dry weights of corn and soybean shoots were significantly higher than those of non-inoculated plants, showing increases of more than 47% for both strains and crops. However, soybean root dry weight did not increased after bacterial inoculation with either strain. The colonization behavior of RZ2MS16 was assessed using GFP-labeling combined with fluorescence microscopy and a cultivation-based approach for quantification. RZ2MS16:gfp was able to colonize the roots and shoots of corn and soybean, revealing an endophytic behavior.

Petroleum biodegrading and co-resistance to antibiotics by Serratia marcescens strain isolated in Coari, Amazonas / Biodegradação do petróleo e corresistência a antibióticos por Serratia marcescens isolada em Coari, Amazonas

Serratia marcescens is a Gram-negative bacillus, anaerobic facultative belonging to the family Enterobacteriaceae. S. marcescens strains are able to grow in the presence of different xenobiotic compounds, among them, petroleum and heavy metals. Xenobiotic resistant strains develop concomitant resistance to multiple antibiotics, referred to as co-resistance. The AMS212 strain was submitted to the microplate qualitative DCPIP - redox 2,6 dichlorophenol indophenol method. The quantitative test was carried out in Erlenmeyer flasks, followed by the change of color with the absorbance readings, trough the colorimetric method. The antibiotic resistance profile was evaluated by the Kirby -Bauer method. In the qualitative assay, the AMS212 strain altered the color of the DCPIP, which changed from blue to colorless, confirming that petroleum biodegradation occurred. In the quantitative test, the readings were decreasing, confirming that the concentration of DCPIP decreased as a function of the incubation time. The susceptibility test revealed that the AMS212 strain presented multiresistance to four different antibiotics. S. marcescens presented high performance in the biodegradation of petroleum, opening possibility to use it in projects involving the remediation of impacted areas. The expression of the antibiotic co-resistance phenotype confirms that the AMS212 strain is able to withstand different environmental aggressions.

Serratia marcescens é um bacilo Gram-negativo, anaeróbio facultativo, pertencente à família Enterobacteriaceae. Linhagens de S. marcescens são capazes de crescer na presença de diferentes compostos xenobióticos, dentre eles, petróleo e metais pesados. Linhagens resistentes a xenobióticos desenvolvem concomitante resistência a múltiplos antibióticos, denominada corresistência. A linhagem AMS212 foi submetida ao método colorimétrico com indicador DCPIP - redox 2,6 diclorofenol indofenol, qualitativo, em microplacas. O teste quantitativo foi realizado em frascos Erlenmeyer, acompanhando-se a mudança de coloração, com as leituras das absorbâncias. Avaliou-se o perfil de resistência a antibióticos pelo método de Kirby-Bauer. No ensaio qualitativo, a linhagem AMS212 alterou a cor do DCPIP, que passou de azul para incolor, confirmando que ocorreu biodegradação do petróleo. No teste quantitativo, as leituras foram decrescentes, confirmando que a concentração do DCPIP diminuiu em função do tempo de incubação. O teste de susceptibilidade revelou que a linhagem AMS212 apresenta multirresistência a quatro antibióticos diferentes. S. marcescens apresentou alto desempenho na biodegradação do petróleo, abrindo possibilidade de utilizá-la em projetos envolvendo a remediação de áreas impactadas. A expressão do fenótipo de corresistência a antibióticos confirma que a linhagem AMS212 é capaz de resistir a diferentes agressões ambientais.

Biosurfactants produced by Microbacterium sp, isolated from aquatic macrophytes in hydrocarbon-contaminated area in the Rio Negro, Manaus, Amazonas / Biossurfactantes produzidos por Microbacterium sp, isolada de macrófita aquática em área impactada por hidrocarbonetos no rio Negro, Manaus, Amazonas

Endophytic bacteria isolated from Eichhornia crassipes (Mart) Solms., collected in oil contaminated wastewater of effluent generated by Petrobras refinery in Manaus were investigated to determine their potential for producing biosurfactants. Assay with 2.6-dichlorophenol indophenol (DCPIP) indicator to verify hydrocarbon biodegradation activity; oil emulsification test; drop-collapse method; surface tension and growth curve of biosurfactant production. The M87 Microbacterium sp. strain chosen for this work was identified by the sequencing of the rDNA region and the chemical characterization was performed by FTIR, UFLC/MS and 1H RMN techniques. The selected bacterial isolate provided 3g L-1 of biosurfactant, using diesel oil as sole carbon source, being efficient in biodegrading oil as demonstrated by the DCPIP test. Fractions obtained by column chromatography were efficient in reducing water surface tension around 40 mN m-1, especially fraction 1, which reduced it to 34.17 mN m-1. The different techniques of chemical analysis used for the identification of the biosurfactant isolate indicated that this is probably a long - chain fatty acid lipid type, which may be used in the future as both biosurfactant in decontamination processes of hydrocarbon-polluted areas or as bioemulsifier in countless processes, since it exhibited no toxicity as determined by Alamar Blue assay.

Foram investigadas bactérias endofíticas isoladas de Eichhornia crassipes (Mart.) Solms., coletadas em águas contaminadas com resíduos de petróleo em um afluente da refinaria da Petrobrás/Manaus, para avaliação da produção de biossurfactantes. Para selecionar o micro-organismos à produção e caracterização de biossurfactantes, foram realizados os seguintes testes: a descoloração do indicador 2,6 indofenol (DCPIP), emulsificação do diesel, colapso da gota, tensão superficial e curva de produção. A caracterização química foi realizada por meio das técnicas de FT-IR, UFLC/MS e RMN1H. A bactéria M87 Microbacterium neste estudo, foi identificada pelo sequenciamento da região rDNA e produziu 3g L-1 de biossurfactantes utilizando o diesel como fonte de carbono, mostrando-se eficiente na ação biodegradadora do petróleo, por meio do teste de Indofenol (DCPIP). As frações obtidas, mostraram-se eficazes na redução da tensão superficial da água abaixo de 40 mN m-1, com destaque para a fração 1 que reduziu a tensão superficial para 34,17 mN m-1. Pelas análises química utilizadas, pode-se inferir que, provavelmente, se trata de um ácido graxo de cadeia longa, que pode ser utilizado futuramente tanto como biossurfactante em processos de descontaminação de ambientes impactados por hidrocarbonetos, assim como bioemulsificante em inúmeros processos uma vez que não apresentou toxicidade por meio do teste realizado.

Biodegradation of the fungicide carbendazim by bacteria from Coriandrum sativum L rhizosphere / Biodegradação do agrotóxico carbendazim por bactérias da rizosfera de Coriandrum sativum L

The biocidal agrochemicals commonly used in agriculture can remain in the soil, affecting the environmental conditions and causing serious risks to health. Knowing that soil microorganisms, especially those from the rhizosphere, can degrade environmental xenobiotics, it was evaluated the potential of bacteria isolated from Coriandrum sativum L. rhizosphere to biodegrade carbendazim (MBC), a fungicide extensively used by agriculturists from rural farming communities in Manaus, Amazonas. Cultures carried out in medium containing carbendazim as a sole carbon source enabled the isolation of 80 bacteria, in the established conditions. Assays to determine degradation potential allowed the selection of the two elite isolates identified as Stenotrophomonas sp. and Ochrobactrum sp. Quantitative assays with each strain individually or in consortium, were carried out using minimal salt medium added with carbendazim (250 µg mL-1) and incubated at 30°C, under agitation (125 rpm) for 21 days. Samples used in the biodegradation test were HPLC analyzed for final fungicide quantitation. The Stenotrophomonas sp. strain was more efficient (68.9%) to degrade carbendazim and showed no toxicity in tests with Artemia salina.

Agrotóxicos são comumente utilizados na produção agrícola, podendo persistir no solo, afetar a qualidade do ambiente e causar sérios riscos à saúde. Sabendo-se que micro-organismos do solo, principalmente aqueles da rizosfera, podem degradar produtos xenobióticos avaliou-se o potencial de bactérias isoladas da rizosfera de Coriandrum sativum L. em degradar carbendazim, um fungicida usado extensivamente em comunidades de agricultores rurais em Manaus, Amazonas. Procedimentos de cultivo em meio, contendo carbendazim como única fonte de carbono, mostraram que 80 bactérias cresceram nas condições estabelecidas. Ensaios de eficiência de degradação permitiram a seleção dos dois melhores isolados que foram identificados como Stenotrophomonas sp. e Ochrobactrum sp. Os ensaios quantitativos, com cada cepa individualmente e com as duas em consórcio, foram conduzidos em meio mínimo contendo sais, acrescido de carbendazim (250 µg mL-1) e incubados a 30°C, 125 rpm, por 21 dias. A quantificação final do fungicida nas amostras do ensaio de biodegradação foi realizada em HPLC. A linhagem Stenotrophomonas sp. apresentou maior eficiência, degradando 68,9% do total de carbendazim e não apresentou toxicidade nos testes realizados com Artemia salina.

Endophytic cultivable bacterial community obtained from the Paullinia cupana seed in Amazonas and Bahia regions and its antagonistic effects against Colletotrichum gloeosporioides.

Guarana (Paullinia cupana var. sorbilis) is a plant from the Amazonas region with socio-economic importance. However, guarana production has been increasingly affected by unfavorable conditions resulting from anthracnose, caused by the Colletotrichum fungal genus, which primarily affects mainly the Amazonas region. The aim of the present study was to isolate bacterial endophytes from the seeds of guarana plants obtained from Amazonas region and the Northeast state of Bahia, a region where this disease is not a problem for guarana plantations. The number of bacterial Colony Forming Units (CFU/g seeds) was 2.4 × 10(4) from the Bahia and 2.9 × 10(4) from the Amazonas region. One hundred and two isolated bacteria were evaluated in vitro against the phytopathogenic strain Colletotrichum gloeosporioides L1. These isolates were also analyzed for the enzymatic production of amylase, cellulase, protease, pectinase, lipase and esterase. Approximately 15% of isolates, showing high antagonistic activity, and the production of at least one enzyme were identified through the partial sequencing of 16S rDNA. The genus Bacillus was the most frequently observed, followed by Paenibacillus, Ochrobactrum, Microbacterium and Stenotrophomonas. Proteolytic activity was observed in 24 isolates followed by amylolytic, pectinolytic and cellulolytic activities. No esterase and lipase production was detected. Most of the isolates, showing antagonistic effects against C. gloeosporioides and high enzymatic activities, were isolated from the anthracnose-affected region. A biocontrol method using the endophytes from guarana seeds could be applied in the future, as these bacteria are vertically transferred to guarana seedlings.

Endophytic fungi from the Amazonian plant Paullinia cupana and from Olea europaea isolated using cassava as an alternative starch media source.

Endophytic fungi live inside plants, apparently do not cause any harm to their hosts and may play important roles in defense and growth promotion. Fungal growth is a routine practice at microbiological laboratories, and the Potato Dextrose Agar (PDA) is the most frequently used medium because it is a rich source of starch. However, the production of potatoes in some regions of the world can be costly. Aiming the development of a new medium source to tropical countries, in the present study, we used leaves from the guarana (a tropical plant from the Amazon region) and the olive (which grows in subtropical and temperate regions) to isolate endophytic fungi using PDA and Manihot Dextrose Agar (MDA). Cassava (Manihot esculenta) was evaluated as a substitute starch source. For guarana, the endophytic incidence (EI) was 90% and 98% on PDA and MDA media, respectively, and 65% and 70% for olive, respectively. The fungal isolates were sequenced using the ITS- rDNA region. The fungal identification demonstrated that the isolates varied according to the host plant and media source. In the guarana plant, 13 fungal genera were found using MDA and six were found using PDA. In the olive plant, six genera were obtained using PDA and 4 were obtained using MDA. The multivariate analysis results demonstrated the highest fungal diversity from guarana when using MDA medium. Interestingly, some genera were isolated from one specific host or in one specific media, suggesting the importance of these two factors in fungal isolation specificity. Thus, this study indicated that cassava is a feasible starch source that could serve as a potential alternative medium to potato medium.

Bacterial diversity in the saliva of patients with different oral hygiene indexes.

The objective of the present study was to evaluate the bacterial diversity in the saliva of patients with different oral hygiene indexes using of two 16S rRNA gene libraries. Each library was composed of samples from patients with different averages of the differentiated Silness-Löe biofilm index: the first library (A) with an index between 1.0 and 3.0 (considered a high index) and the second library (B) between 0 and 0.5 (considered a low index). Saliva DNA was extracted and the 16S rRNA gene was amplified and cloned. The obtained sequences were compared with those stored at NCBI and RDP GenBank. The saliva of patients with high index presented five known genera - Streptococcus, Granulicatella, Gemella, Veillonella and Peptostreptococcus - and 33.3% of nonculturable bacteria grouped into 23 operational taxonomic units (OTUs). The saliva of patients with low index differed significantly from the first library (p=0.000) and was composed of 42 OTUs distributed into 11 known genera - Streptococcus, Granulicatella, Gemella, Veillonella, Oribacterium, Haemophilus, Escherichia, Neisseria, Prevotella, Capnocytophaga, Actinomyces - including 24.87% of nonculturable bacteria. It was possible to conclude that there is greater bacterial diversity in the saliva of patients with low dental plaque in relation to patients with high dental plaque.

Purification and characterization of a lectin of the Swartzieae Legume Taxa.

This work aimed at describing the first biochemical and structural data of a lectin belonging to Swartzieae, a primitive Legume Taxa. A lactose-binding seed lectin (SLL) was purified by affinity chromatography of crude saline extracts of Swartzia laevicarpa on immobilized lactose. The SLL agglutinated rabbit erythrocytes but not rat or human (A, B, O) erythrocytes. Lectin activity was retained after heating at 100 �C for 15 min and was best inhibited by Nacetylgalactosamine, lactose and galactose. The lectin exhibited a single electrophoretic pattern that corresponded to a molecular mass of 29,000 Da, which was confirmed by MS analysis. In addition, the lectin reacted positively with Schiff's reagent. The unique N-terminal amino acid sequence (39 residues) and the internal peptide sequence were determined by Edman degradation and MS/MS, respectively. The sequencing revealed complete homology of the SLL with legume lectins belonging to primitive groups (Dalbergieae and Sophoreae). The SLL (at 1 mg/ml) did not exhibit antifungal activity against various phytopathogens or cytotoxicity (at 100 µg/ml) towards different cancer cell lines.

Bacterial diversity in the saliva of patients with different oral hygiene indexes

The objective of the present study was to evaluate the bacterial diversity in the saliva of patients with different oral hygiene indexes using of two 16S rRNA gene libraries. Each library was composed of samples from patients with different averages of the differentiated Silness-Löe biofilm index: the first library (A) with an index between 1.0 and 3.0 (considered a high index) and the second library (B) between 0 and 0.5 (considered a low index). Saliva DNA was extracted and the 16S rRNA gene was amplified and cloned. The obtained sequences were compared with those stored at NCBI and RDP GenBank. The saliva of patients with high index presented five known genera - Streptococcus, Granulicatella, Gemella, Veillonella and Peptostreptococcus - and 33.3% of nonculturable bacteria grouped into 23 operational taxonomic units (OTUs). The saliva of patients with low index differed significantly from the first library (p=0.000) and was composed of 42 OTUs distributed into 11 known genera - Streptococcus, Granulicatella, Gemella, Veillonella, Oribacterium, Haemophilus, Escherichia, Neisseria, Prevotella, Capnocytophaga, Actinomyces - including 24.87% of nonculturable bacteria. It was possible to conclude that there is greater bacterial diversity in the saliva of patients with low dental plaque in relation to patients with high dental plaque.

O objetivo do presente estudo foi avaliar a diversidade bacteriana da saliva de pacientes com diferentes índices de higiene bucal através da construção de duas bibliotecas do gene 16S rRNA. Cada biblioteca foi composta por amostras de saliva de pacientes com índice de biofilme dental de Silness-Löe diferenciado, sendo a primeira (A) com índice de 1,0 a 3,0 (denominada de alto índice) e a segunda (B), entre 0 a 0,5 (denominada de baixo índice). O DNA da saliva foi extraído e o gene 16S rRNA foi amplificado, clonado e sequenciado. As sequências obtidas foram comparadas com aquelas armazenadas no GenBank do NCBI e RDP. A saliva de pacientes com alto índice de biofilme dental apresentou cinco gêneros conhecidos: Streptococcus, Granulicatella, Gemella, Veillonella e Peptostreptococcus e 33,3% de bactérias não-cultivadas, agrupados em 23 unidades taxonômicas operacionais (UTOs). A saliva de pacientes com baixo índice de biofilme dental, foi diferente significativamente da primeira (p=0,000) e foi composta de 42 UTOs, distribuídas em 11 gêneros conhecidos: Streptococcus, Granulicatella, Gemella, Veillonella, Oribacterium, Haemophilus, Escherichia, Neisseria, Prevotella, Capnocytophaga, Actinomyces, além de 24,87% de bactérias não-cultivadas. Pode-se concluir que existe maior diversidade bacteriana na saliva de pacientes com baixo índice de biofilme dental em relação a pacientes com alto índice de biofilme dental.

Molecular approaches for structural characterization of Bothrops L-amino acid oxidases with antiprotozoal activity: cDNA cloning, comparative sequence analysis, and molecular modeling.

Two l-amino acid oxidases (LAAOs) were identified by random sequencing of cDNA libraries from the venom glands of Bothrops moojeni(BmooLAAO) and Bothrops jararacussu(Bjussu LAAO). Phylogenetic analysis involving other SV-LAAOs showed sequence identities within the range 83-87% being closely related to those from Agkistrodon and Trimeresurus. Molecular modeling experiments indicated the FAD-binding, substrate-binding, and helical domains of Bmoo and Bjussu LAAOs. The RMS deviations obtained by the superposition of those domains and that from Calloselasma rhodostoma LAAO crystal structure confirm the high degree of structural similarity between these enzymes. Purified BjussuLAAO-I and BmooLAAO-I exhibited antiprotozoal activities which were demonstrated to be hydrogen-peroxide mediated. This is the first report on the isolation and identification of cDNAs encoding LAAOs from Bothrops venom. The findings here reported contribute to the overall structural elucidation of SV-LAAOs and will advance the understanding on their mode of action.

Antimicrobial activity of Arctium lappa constituents against microorganisms commonly found in endodontic infections

A atividade antimicrobiana de extratos brutos de folhas de Arctium lappa, bem como de suas fases, foi avaliada in vitro. Os microrganismos Enterococcus faecalis, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis e Candida albicans, comuns na cavidade bucal, especificamente em infecções endodônticas, foram utilizados. O método de difusão em Agar permitiu a detecção da fase hexânica como inibitória do crescimento microbiano. Ensaios de bioautografia identificaram substâncias antimicrobianas presentes no extrato. Os resultados demonstraram a presença, na fase hexânica bruta e em suas sub-frações, de constituintes que têm Rf (fatores de retenção) em três zonas distintas, sugerindo a presença de ativos com estruturas químicas de diferentes polaridades, que exibiram especificidade contra os microrganismos alvos. Conclui-se que os constituintes de Arctium lappa apresentam um grande potencial de inibição microbiana contra os microrganismos endodônticos estudados.

Benzopyrans from Curvularia sp., an endophytic fungus associated with Ocotea corymbosa (Lauraceae).

An isolate of Curvularia sp. was obtained from the leaves of Ocotea corymbosa, a native plant of the Brazilian Cerrado. The ethyl acetate extract from culture of this fungus afforded two benzopyran derivatives: (2'S)-2-(propan-2'-ol)-5-hydroxy-benzopyran-4-one (2) and 2,3-dihydro-2-methyl-benzopyran-4,5-diol (4); and two known benzopyrans: 2-methyl-5-methoxy-benzopyran-4-one (1) and (2R)-2,3-dihydro-2-methyl-5-methoxy-benzopyran-4-one (3). The structures of 2 and 4 were established on the basis of comprehensive spectroscopic analysis, mainly using 1D and 2D NMR experiments. The benzopyrans 1 and 2 showed weak in vitro antifungal activity against Cladosporium sphaerospermum and C. cladosporioides. Analyses of the biological activities were also carried out on HeLa (human cervix tumor) and CHO (Chinese hamster ovary) cells, aiming to evaluate their potential effects on mammalian cell line proliferation. Results from both cell lines indicated that compound 2 was able to induce cell proliferation: 70% on HeLa cells and 25% on CHO cells.

Antimicrobial activity of Arctium lappa constituents against microorganisms commonly found in endodontic infections.

This study evaluated in vitro the antimicrobial activity of rough extracts from leaves of Arctium lappa and their phases. The following microorganisms, commonly found in the oral cavity, specifically in endodontic infections, were used: Enterococcus faecalis, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis and Candida albicans. The agar-diffusion method allowed detection of the hexanic phase as an inhibitor of microbial growth. Bioautographic assays identified antimicrobial substances in the extract. The results showed the existence, in the rough hexanic phase and in its fractions, of constituents that have retention factors (Rf) in three distinct zones, thereby suggesting the presence of active constituents with chemical structures of different polarities that exhibited specificity against the target microorganisms. It may be concluded that the Arctium lappa constituents exhibited a great microbial inhibition potential against the tested endodontic pathogens.

Atividade antimicrobiana de fungos endofíticos isolados de plantas tóxicas da amazônia: Palicourea longiflora (aubl. ) rich e Strychnos cogens bentham / Antimicrobial activity of endophytic fungi isolated from amazonian toxic plants: Palicourea longiflora (aubl. ) rich and Strychnos cogens bentham

Das plantas tóxicas da Amazônia Palicourea longiflora e Strychnos cogens foram isolados 571 fungos endofíticos e 74 bactérias endofíticas. Palicourea longiflora (Rubiaceae) e outras espécies desse gênero estão relacionadas a 90 por cento das mortes de gado na região Amazônica. Strychnos cogens (Loganiaceae) e outras espécies de Strychnos são utilizadas pelos indígenas na confecção de "curares". Entre os endófitos isolados de P. longiflora foram identificados os fungos: Colletotrichum sp. e seu telemorfo Glomerella sp., Guignardia sp., Aspergillus niger, Phomopsis sp. e Xylaria sp., além da bactéria Burkholderia gladioli, pertencente a um grupo de fixadoras de nitrogênio. Dos isolados de S. cogens foram identificados os fungos: Colletotrichum sp., Guignardia sp., Aspergillus niger e Trichoderma sp. Uma amostra de 79 isolados fúngicos teve seus metabólitos extracelulares bioensaiados contra microrganismos patogênicos e fitopatogênicos: 19 isolados inibiram um ou mais microrganismos-teste. Dos oito isolados com melhores resultados de inibição, as móleculas bioativas eram menores que 12.000 daltons, fato verificado pela diálise dos metabólitos.