Chemoenzymatic epoxidation of citronellol catalyzed by lipases

AbstractThe chemoenzymatic epoxidation of a terpene alcohol, citronellol, is reported. Some experimental conditions, such as the use of lipases from different sources, oxidizing agents (H2O2 or urea–hydrogen peroxide, UHP), reaction time, acyl donor type (C6–C16), temperature (15–40°C) and the influence of organic media, were evaluated. In most cases, citronellol oxide 2 or the ester citronellol oxide 3 were obtained. Depending on the reaction conditions, high yields of products 2 or 3 were obtained (>99%). CAL-B was the most effective catalyst in this reaction. For epoxide 2, the highest yields of 80% and 77% were obtained at 20°C and 25°C, respectively, using UHP as an oxidizing agent and octanoic acid as an acyl donor. The organic medium appears to be one of the most important parameters in the reaction. Using chloroform or dichloromethane, product 2 was obtained at a >99% yield after 24h. When different mixtures consisting of varied organic solvents and an imidazolium-based ionic liquid (IL) were used, the results were dependent on both the solvent and IL counter-ion (18–75%)

Regioselective acylation of d-ribono-1,4-lactone catalyzed by lipases

AbstractLipases from ten different sources and two mycelium-bound lipases isolated from Amazonian fungi were screened as biocatalysts in the acylation reaction of d-ribono-1,4-lactone with a variety of acyl donors in non-aqueous media. Several reaction parameters were evaluated including the type and amount of enzyme, acyl donor, and organic solvent, as well as the influence of water and the recyclability of the catalyst. When Candida antarctica lipase (CAL-B) was used, the acylation was highly regioselective and the corresponding 5-acyl-d-ribono-1,4-lactones were observed as the sole product. The best conversion (>99%) into 5-acetyl-d-ribono-1,4-lactone was obtained through the combination of vinyl acetate as the acetyl donor and 10mg (100U) of CAL-B in dry acetonitrile after 24h. However, lipases from Burkholderia cepacia (PSL-C and PSL-D), Pseudomonas fluorescens (AK) and Thermomyces langinosus (Lipozyme TL-IM) gave mixtures of mono-, di- and tri-acetylated products in lower conversions. CAL-B maintained its catalytic activity during five cycles of repeated use when decanoic and dodecanoic acids were employed as acyl donors in the acylation of d-ribono-1,4-lactone

Bioclimatic buildings strategies for the climate of Araras city, São Paulo - Brazil

The concept of bioclimatic architecture or passive solar architecture can be defined as an architecture that includes the climate as an important variable in the design process. Through the use of bioclimatic strategies the environment comfort can be obtained naturally for users of buildings, which depending on the climate, the construction techniques and the type of use. Considering these aspects, the main objective of this work is to identify bioclimatic strategies for buildings for the climate of Araras city, countryside of São Paulo State - Brazil, based on climatic characterization of the city and in the study of design guidelines indicated by the Brazilian Code NBR 15220-3, the Brazilian Bioclimatic Zoning. According to the code, the climate of Araras is inserted in Bioclimatic Zone 4. For this climate the main indicated strategies for winter are the use of solar passive heating and massive internal walls in buildings. For summer, the use of evaporative cooling and ventilation are indicated. Based on this information were established initial guidelines for thermal comfort and energy efficiency for projects of buildings in the climate of Araras-SP

Genetic diversity and evolutionary relationships among Legionella pneumophila clinical isolates, Portugal, 1987 to 2012

This study was supported by the Portuguese Foundation for Science and Technology (FCT) [grant number PTDC/SAU-ESA/64269/2006].The genetic diversity of 89 clinical Legionella isolates, collected between 1987 and 2012, in 22 hospitals from the five regions of Portugal, was analysed in this study using monoclonal antibodies (MAbs) of the Dresden panel and the sequence-based typing (SBT) protocol. The eBURST algorithm was used to infer levels of relatedness between isolates. All isolates collected were Legionella pneumophila, which were further characterised into four subgroups by MAbs, and 30 sequence types (STs) by SBT. Twelve of the STs were unique to Portugal; one of them (ST100) was represented by 32 epidemiologically related isolates. The ST44 was the profile with the highest number of epidemiologically unrelated isolates. The eBURST analyses indicate that, within the group formed by the 30 STs identified in this study, 17 STs were genetically close to at least another ST in the group. The comparison between the eBURST diagrams obtained with the STs from this study and the entire SBT database of the European Working Group for Legionella, showed that 24 (seven of them unique to Portugal) of our 30 STs were related with STs identified in others countries. These results suggest that the population of L. pneumophila clinical strains in Portugal includes both worldwide and local strains.publishersversionpublishe

High Trypanosoma spp. diversity is maintained by bats and triatomines in Espírito Santo state, Brazil

The aim of this study was to reevaluate the ecology of an area in the Atlantic Forest, southeast Brazil, where Chagas disease (CD) has been found to occur. In a previous study, immediately after the occurrence of a CD case, we did not observe any sylvatic small mammals or dogs with Trypanosoma cruzi cruzi infections, but Triatoma vitticeps presented high T. c. cruzi infection rates. In this study, we investigated bats together with non-volant mammals, dogs, and triatomines to explore other possible T. c. cruzi reservoirs/hosts in the area. Seventy-three non-volant mammals and 186 bats were captured at three sites within the Guarapari municipality, Espírito Santo state. Rio da Prata and Amarelos sites exhibited greater richness in terms of non-volant mammals and bats species, respectively. The marsupial Metachirus nudicaudatus, the rodent Trinomys paratus, and the bats Artibeus lituratus and Carollia perspicillata were the most frequently captured species. As determined by positive hemocultures, only two non-volant mammals were found to be infected by Trypanosoma species: Monodelphis americana, which was infected by T. cascavelli, T. dionisii and Trypanosoma sp., and Callithrix geoffroyi, which was infected by T. minasense. Bats presented T. c. cruzi TcI and TcIII/V, T. c. marinkellei, T. dionisii, T. rangeli B and D, and Trypanosoma sp. infections. Seven dogs were infected with T. cruzi based only on serological exams. The triatomines T. vitticeps and Panstrongylus geniculatus were found to be infected by trypanosomes via microscopy. According to molecular characterization, T. vitticeps specimens were infected with T. c. cruzi TcI, TcII, TcIII/V, and TcIV, T. c. marinkellei and T. dionisii. We observed high trypanosome diversity in a small and fragmented region of the Atlantic Forest. This diversity was primarily maintained by bats and T. vitticeps. Our findings show that the host specificity of the Trypanosoma genus should be thoroughly reviewed. In addition, our data show that CD cases can occur without an enzootic cycle near residential areas

Esquemas de pintura para estruturas marítimas

Nas últimas décadas tem-se verificado um grande aumento das aplicações das ligas de alumínio nas estruturas marítimas. Os danos estruturais que se têm verificado em embarcações devem-se, em grande parte, a problemas de corrosão. Assim, as ligas de alumínio têm que ter uma protecção anticorrosiva adequada. As estruturas marítimas, nomeadamente os cascos dos navios devem ser mantidos preferencialmente livres de organismos por forma a minimizar a resistência ao atrito e consequentemente o consumo de combustível. Para tal são aplicados revestimentos anti-incrustantes para evitar a fixação destes organismos. Nos últimos anos têm-se verificado grandes desenvolvimentos de investigação, desenvolvimento e inovação (IDI) para obtenção de tintas anti-incrustantes (AI) com uma melhor eficiência anti-incrustante em total concordância com a legislação ambiental. O principal objetivo deste estudo reside na avaliação da proteção anticorrosiva e da eficiência anti-incrustante de 3 diferentes esquemas de pintura envolvendo tintas AI com diferentes biocidas. Estas avaliações envolveram ensaios de envelhecimento artificial (resistência ao nevoeiro salino, à imersão em água do mar sintética e à delaminação catódica) e de exposição natural durante dois anos. Estes esquemas de pintura foram caracterizados visualmente, em termos de espessura e em termos morfológicos e químicos por microscopia electrónica de varrimento com espectrometria de dispersão de energias (SEM/EDS), por espectroscopia de infravermelho com transformada de Fourier (FTIR) e por difracção de raios-X (XRD). Finalmente referem-se algumas das linhas de investigação actualmente em curso no domínio da luta contra a fixação dos organismos marinhos em estruturas marítimas

Functional and genomic characterization of Komagataeibacter uvaceti FXV3, a multiple stress resistant bacterium producing increased levels of cellulose

Funding Information: This work was supported by the Applied Molecular Biosciences Unit - UCIBIO which is financed by national funds from FCT ( UIDB/04378/2020). Funding Information: Funding from INTERFACE Programme, through the Innovation, Technology and Circular Economy Fund (FITEC), is gratefully acknowledged. Publisher Copyright: © 2021Bacterial cellulose is one of the most promising biomaterials for the development of a wide array of novel biotechnological solutions. Nevertheless, the commercial production of bacterial cellulose is still a challenge and obtaining novel strains presenting increased cellulose biosynthesis and stress resistance properties is of extreme importance. This work demonstrates the increased stress resistance, cellulose production abilities, and overall genomic properties of Komagataeibacter uvaceti FXV3, a novel cellulose-producing and stress resistant strain isolated from a fermented grape must. K. uvaceti FXV3 was able to grow under several stress conditions, including the presence of high concentrations of ethanol (up to 7.5 % v/v), a trait that is not observed in the model strain K. xylinus CECT 7351T. Moreover, K. uvaceti FXV3 produced increased concentrations of cellulose (4.31 mg/mL, 7 days after inoculation-DAI) when compared to K. xylinus CECT 7351T (1.42 mg/mL, 7 DAI). Moreover, the detailed analysis of strain FXV3 genome revealed the presence of several genes involved in cellulose and acetan biosynthesis, quorum-sensing and quenching mechanisms, carbohydrate, amino acid, alcohol and aldehyde metabolism, as well as several other genes involved in stress resistance. Additionally, comparative genomic analysis revealed the increased prevalence of stress resistance genes in K. uvaceti FXV3 when compared to K. xylinus CECT 7351T. Ultimately, this study reveals the increased biotechnological potential of K. uvaceti FXV3 and brings new insights into the genetics behind Komagataeibacter stress resistance and cellulose production abilities.publishersversionpublishe

Visceral leishmaniasis in the State of Maranhão, Brazil: evolution of an epidemic

The authors provide a brief report on the historical evolution of visceral leishmaniasis in the State of Maranhão, Brazil, evaluating possible factors for growth of the disease in the State and control measures by the Brazilian Ministry of Health to integrate health services finto the maintenance of control programs.Os autores fazem um breve relato da evolução histórica da leishmaniose visceral no Estado do Maranhão, Brasil, avaliando as possíveis causas da expansão da referida doença no Estado, assim como as medidas de controle adotadas pelo Ministério da Saúde objetivando a diminuição da incidência da mesma.Universidade Federal do Maranhão Faculdade de Medicina Departamento de PatologiaEscola Paulista de MedicinaUNIFESP, EPMSciEL

ANESTRO pós-parto em ovelhas deslanadas.

Anestro; Fases em que ocorre o anestro; Principais fatores que influenciam a duração do anestro pós-parto; Efeitos da amamentação no retorno ao estro pós-parto; Efeitos da nutrição no retorno ao estro pós-parto; Práticas de manejo que contribuem para antecipar o estro pós-parto. Equipe Técnica: Tânia Maria Leal, Maria do Perpétuo Socorro Cortez Bona do Nascimento, Raimundo Bezerra de Araújo Neto, Raimundo Bezerra de Araújo Neto, Adriana Mello de Araújo.bitstream/item/52990/1/FDAnestro0001.pd