Exploring Metagenomic Enzymes: A Novel Esterase Useful for Short-Chain Ester Synthesis

Enzyme-mediated esterification reactions can be a promising alternative to produce esters of commercial interest, replacing conventional chemical processes. The aim of this work was to verify the potential of an esterase for ester synthesis. For that, recombinant lipolytic enzyme EST5 was purified and presented higher activity at pH 7.5, 45 °C, with a Tm of 47 °C. Also, the enzyme remained at least 50% active at low temperatures and exhibited broad substrate specificity toward p-nitrophenol esters with highest activity for p-nitrophenyl valerate with a Kcat/Km of 1533 s−1 mM−1. This esterase exerted great properties that make it useful for industrial applications, since EST5 remained stable in the presence of up to 10% methanol and 20% dimethyl sulfoxide. Also, preliminary studies in esterification reactions for the synthesis of methyl butyrate led to a specific activity of 127.04 U·mg−1. The enzyme showed higher esterification activity compared to other literature results, including commercial enzymes such as LIP4 and CL of Candida rugosa assayed with butyric acid and propanol which showed esterification activity of 86.5 and 15.83 U·mg−1, respectively. In conclusion, EST5 has potential for synthesis of flavor esters, providing a concept for its application in biotechnological processes.</jats:p

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Assessment of risk scores to predict mortality of COVID-19 patients admitted to the intensive care unit

ObjectivesTo assess the ABC2-SPH score in predicting COVID-19 in-hospital mortality, during intensive care unit (ICU) admission, and to compare its performance with other scores (SOFA, SAPS-3, NEWS2, 4C Mortality Score, SOARS, CURB-65, modified CHA2DS2-VASc, and a novel severity score).Materials and methodsConsecutive patients (≥ 18 years) with laboratory-confirmed COVID-19 admitted to ICUs of 25 hospitals, located in 17 Brazilian cities, from October 2020 to March 2022, were included. Overall performance of the scores was evaluated using the Brier score. ABC2-SPH was used as the reference score, and comparisons between ABC2-SPH and the other scores were performed by using the Bonferroni method of correction. The primary outcome was in-hospital mortality.ResultsABC2-SPH had an area under the curve of 0.716 (95% CI 0.693–0.738), significantly higher than CURB-65, SOFA, NEWS2, SOARS, and modified CHA2DS2-VASc scores. There was no statistically significant difference between ABC2-SPH and SAPS-3, 4C Mortality Score, and the novel severity score.ConclusionABC2-SPH was superior to other risk scores, but it still did not demonstrate an excellent predictive ability for mortality in critically ill COVID-19 patients. Our results indicate the need to develop a new score, for this subset of patients

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Produção de lipases por fungos termofílicos e mesofílicos e uso na produção de biodiesel etílico

O biodiesel é uma alternativa ao diesel convencional que pode ser produzido a partir da reação de transesterificação entre triglicerídeos presentes em óleos vegetais ou gordura animal e alcoóis, como o metanol ou etanol. Uma rota promissora desta reação é a catálise enzimática, utilizando lipases. Este trabalho teve objetivo de selecionar cepas fúngicas com capacidade de produzir enzimas lipolíticas com propriedade de transesterificação e a imobilização destas enzimas para produção de biodiesel etílico. Para selecionar as linhagens com atividade lipolítica, foram realizados zimogramas com corante Rodamina B. Foram selecionadas três cepas fúngicas termofílicas e dezoito mesofílicas. As atividades hidrolíticas das linhagens fúngicas selecionadas foram comfirmadas com substrato cromogênico, p-nitrofenil palmitato (pNPP). As linhagens pré-selecionadas foram submetidas ao teste de transesterificação com óleo de soja e etanol, e os produtos desta reação foram analisados por GC-FID. Uma cepa fúngica identificada como Acremonium sp P24 foi selecionada para dar continuidade ao trabalho. A lipase bruta produzida a partir do bagaço de cana de açúcar foi concentrada por ultrafiltração e apresentou atividade hidrolítica ótima a 35ºC. O processo de imobilização mais eficiente para a realização de síntese foi aquele em que se utilizou as hifas do fungo Acremonium sp P24 crescidas no próprio farelo de trigo como suporte. A análise de variância para os experimentos mostrou que entre as variáveis estudadas (temperatura de reação, razão molar óleo/álcool, concentração enzimática e razão v/v óleo/hexano), somente a concentração enzimática como variável significativa e indicou a concentração de 10 % de hifas imobilizadas...Biodiesel is an alternative to conventional diesel, which can be produced from the transesterification reaction of triglycerides found in vegetable oils or animal fat and alcohols such as methanol or ethanol. A promising route to this reaction is the enzymatic catalysis using lipases. This work aimed at selecting fungal strains capable of producing lipolytic enzymes with property of transesterification and immobilization of such enzymes for the production of ethylic biodiesel. In order to select strains with lipolytic activity, zymograms using dye Rhodamine B were performed. Three thermophilic and eighteen mesophilic fungal strains were selected. The hydrolytic activities of the selected fungal strains were confirmed by using chromogenic substrate p-nitrophenyl palmitate (pNPP). The pre-selected strains were then submitted to transesterification test with ethanol and soybean oil, and the products of such a reaction were analyzed by GC-FID. Only the fungal strain identified as Acremonium sp P24 was selected to carry out the work. The crude lipase produced from sugar cane bagasse was concentrated by ultrafiltration and showed optimal hydrolytic activity at 35°C. The most efficient immobilization process in order to carry out synthesis was the one in which hyphae of the fungus Acremonium sp P24 was used, they grown on wheat bran as support. Analysis of variance for the experiments showed that among the studied variables (reaction temperature, molar ratio of oil/alcohol, enzyme concentration and ratio v/v oil/hexane), only the enzymatic concentration as a significant variable and indicated a concentration of 10% of immobilized hyphae as an optimum point. However, experimentally speaking, the best biodiesel yield was 15.95%, using 7.75% immobilized hyphae, at 31.25°C, with 1:7.5 oil/alcohol molar ratio... (Complete abstract click electronic access below)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Critical role of different immobilized biocatalysts of a given lipase in the selective ethanolysis of sardine oil

Different immobilized derivatives of two lipases were tested as catalysts of the synthesis of ethyl esters of omega-3 fatty acids during the ethanolysis of sardine oil in solvent-free systems at 25 °C. Lipases from Thermomyces lanuginosus (TLL) and Lecitase Ultra (a phospholipase with lipolytic activity) were studied. Lipases were adsorbed on hydrophobic Sepabeads C18 through the open active center and on an anion-exchanger Duolite with the active center exposed to the reaction medium. TLLSepabeads derivatives exhibit a high activity of 9 UI/mg of immobilized enzyme, and they are 20-fold more active than TLLDuolite derivatives and almost 1000-fold more active than Lipozyme TL IM (the commercial derivative from Novozymes). Lecitase-Sepabeads exhibit a high selectivity for the synthesis of the ethyl ester of EPA that is 43-fold faster than the synthesis of the ethyl ester of DHA.This work was sponsored by the Spanish Ministry of Science and Innovation (Projects AGL-2009-07526 and BIO2012-36861). We gratefully recognize the Spanish Ministry of Science and Innovation for the “Ramon y Cajal> contract for G.F.-L. and for the FPI contract to S.M.-P. We also thank Fundaca̧o de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) for granting the 284 scholarship to D.F.M.T.i (BEPE Process 2014/04925-1).Peer Reviewe

Critical role of different immobilized biocatalysts of a given lipase in the selective ethanolysis of sardine oil

Different immobilized derivatives of two lipases were tested as catalysts of the synthesis of ethyl esters of omega-3 fatty acids during the ethanolysis of sardine oil in solvent-free systems at 25 °C. Lipases from Thermomyces lanuginosus (TLL) and Lecitase Ultra (a phospholipase with lipolytic activity) were studied. Lipases were adsorbed on hydrophobic Sepabeads C18 through the open active center and on an anion-exchanger Duolite with the active center exposed to the reaction medium. TLLSepabeads derivatives exhibit a high activity of 9 UI/mg of immobilized enzyme, and they are 20-fold more active than TLLDuolite derivatives and almost 1000-fold more active than Lipozyme TL IM (the commercial derivative from Novozymes). Lecitase-Sepabeads exhibit a high selectivity for the synthesis of the ethyl ester of EPA that is 43-fold faster than the synthesis of the ethyl ester of DHA.This work was sponsored by the Spanish Ministry of Science and Innovation (Projects AGL-2009-07526 and BIO2012-36861). We gratefully recognize the Spanish Ministry of Science and Innovation for the “Ramon y Cajal> contract for G.F.-L. and for the FPI contract to S.M.-P. We also thank Fundaca̧o de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) for granting the 284 scholarship to D.F.M.T.i (BEPE Process 2014/04925-1).Peer Reviewe

Ethyl esters production catalyzed by immobilized lipases is influenced by n-hexane and ter-amyl alcohol as organic solvents

Lipase stability in organic solvent is crucial for its application in many biotechnological processes as biocatalyst. One way to improve lipase’s activity and stability in unusual reaction medium is its immobilization on inert supports. Here, lipases from different sources and immobilized through weak chemical interactions on hydrophobic and ionic supports had their transesterification ability dramatically dependent on the support and also on the solvent that had been used. The ethanolysis of sardine oil was carried out at the presence of cyclohexane and tert-amyl alcohol, in which Duolite A568-Thermomyces lanuginosa lipase derivative achieved 49% of ethyl esters production after 24 h in cyclohexane. The selectivity of immobilized lipases was also studied and, after 3 h of synthesis, the reaction with Duolite A568-Thermomyces lanuginosa derivative in cyclohexane produced 24% ethyl ester of eicosapentaenoic acid and 1.2% ethyl ester of docosahexaenoic acid, displaying a selectivity index of 20 times the ethyl ester of eicosapentaenoic acid. Different derivatives of Candida antarctica lipases fraction B (CALB) and phospholipase Lecitase® Ultra (Lecitase) were also investigated. Along these lines, a combination between these factors may be applied to improve the activity and selectivity of immobilized lipases, decreasing the total cost of the process.The authors thank the financial support from the São Paulo Research Foundation (FAPESP – grants 2012/09054-3 and 2013/00530-0), and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES – grant number 3894/13-4).Peer reviewe