Automated Identification and Classification of Stereochemistry: Chirality and Double Bond Stereoisomerism

Stereoisomers have the same molecular formula and the same atom connectivity and their existence can be related to the presence of different three-dimensional arrangements. Stereoisomerism is of great importance in many different fields since the molecular properties and biological effects of the stereoisomers are often significantly different. Most drugs for example, are often composed of a single stereoisomer of a compound, and while one of them may have therapeutic effects on the body, another may be toxic. A challenging task is the automatic detection of stereoisomers using line input specifications such as SMILES or InChI since it requires information about group theory (to distinguish stereoisomers using mathematical information about its symmetry), topology and geometry of the molecule. There are several software packages that include modules to handle stereochemistry, especially the ones to name a chemical structure and/or view, edit and generate chemical structure diagrams. However, there is a lack of software capable of automatically analyzing a molecule represented as a graph and generate a classification of the type of isomerism present in a given atom or bond. Considering the importance of stereoisomerism when comparing chemical structures, this report describes a computer program for analyzing and processing steric information contained in a chemical structure represented as a molecular graph and providing as output a binary classification of the isomer type based on the recommended conventions. Due to the complexity of the underlying issue, specification of stereochemical information is currently limited to explicit stereochemistry and to the two most common types of stereochemistry caused by asymmetry around carbon atoms: chiral atom and double bond. A Webtool to automatically identify and classify stereochemistry is available at http://nams.lasige.di.fc.ul.pt/tools.ph

Kinetic study of fermentative biosurfactant production by Lactobacillus strains

Screening of biosurfactant-producing ability of four Lactobacillus strains was performed, being shown that for all the tested strains biosurfactant production occurred mainly in the first 4 h. The Lactobacillus strains showed zones of clearing in the blood agar with a diameter <1 cm. The minimum surface tension value of the fermentation broth achieved was 39.5 mN/m for Lactobacillus pentosus CECT-4023 that represents a reduction in the surface tension of 10.5 mN/m comparing with the control. Time courses of glucose, biomass and biosurfactant were modeled according to reported models. Using MRS broth (Man, Rogosa & Sharpe medium for lactobacilli strains) as culture medium, the values estimated by the modeling of biosurfactant were Pmax = 1.6 g of biosurfactant/L and rp/X = 0.091 g/(L h), for Lactobacillus casei CECT-5275, Pmax = 1.7 g/L and rp/X = 0.217 g/(L h) for Lactobacillus rhamnosus CECT-288, Pmax = 1.7 g/L and rp/X = 0.069 g/(L h) for L. pentosus CECT-4023 and Pmax = 1.8 g/L and rp/X = 0.090 g/(L h) for Lactobacillus coryniformis subsp. torquens CECT-25600. Pmax is the maximum concentration of biosurfactant (g/L), and Pr is the ratio between the initial volumetric rate of product formation (rp) and the initial product concentration P0 (g/L). Using whey as production medium, the values estimated by the modeling of biosurfactant for L. pentosus CECT-4023 were Pmax = 1.4 g of biosurfactant/L and rp/X = 0.093 g/(L h). In conclusion, the results obtained for L. pentosus CECT-4023 showed that this is a strong biosurfactant producer strain and that cheese whey can be used as an alternative medium for biosurfactant production

Modeling of biosurfactant production by Lactobacillus Strains

Screening of biosurfactant-producing ability of three Lactobacillus strains was performed, being shown that, for all the tested strains, biosurfactant production is occurring mainly in the first 7 hours. All strains reduced 8 mN/m the surface tension of the fermentation broth at the end of fermentation and lysed blood agar with scores ranging between (++) corresponding to complete hemolysis with a diameter < 1 cm. Time courses of lactose, biomass and biosurfactant were modeled according to reported models, assuming product inhibition. Using optimized MRS broth as culture medium, the values estimated by the modeling of biosurfactant were P_max = 1.4 g of biosurfactant/L and rp/X = 0.137g/L.hˉ¹ for Lactobacillus casei CECT-5275, P_max = 1.5 g/L and rp/X = 0.145g/L.hˉ¹ for Lactobacillus rhamnosus CECT-288 and P_max = 1.5 g/L and rp/X = 0.089 g/L.hˉ¹ for Lactobacillus pentosus CECT-4023. Using whey as production medium, the values obtained for Lactobacillus rhamnosus CECT-288 were P_max = 1.3 g of biosurfactant/L and rp/X = 0.078 g/L.hˉ¹. In conclusion, the results obtained showed that whey can be used as an alternative medium for biosurfactant production by Lactobacillus strains

The effect of bovine milk lactoferrin on human breast cancer cell lines

The evidence that biologically active food components are key environmental factors affecting the incidence of many chronic diseases is overwhelming. However, the full extent of such components in our diet is unknown, as well as our understanding of their mechanisms of action. Beyond their interaction with the gut and intestinal immune functions, more benefits are being tested for whey proteins such as lactoferrin, namely as anti-cancer agents. Lactoferrin is an iron-binding protein that has been reported to inhibit several types of cancer. In the present work, the effects of bovine milk lactoferrin on human breast cancer HS578T and T47D cells were studied. The cells were either untreated or submitted to lactoferrin concentrations ranging from 0. 125 to 125 μM. Lactoferrin decreased 47% and 54% the cell viability of HS578T and T47D, respectively, and increased apoptosis about twofold for both cell lines. Proliferation rates decreased between 40.3 and 63.9% for HS578T and T47D, respectively. T47D cell migration decreased in the presence of the protein. Although the mechanisms of action have still not been unrevealed, the results gathered in this work suggest that lactoferrin interferes with some of the most important steps involved in cancer development.(undefined

Exergy efficiency optimization for gas turbine based cogeneration systems

Energy degradation can be calculated by the quantification of entropy and loss of work and is a common approach in power plant performance analysis. Information about the location, amount and sourc es of system deficiencies are determined by the exergy analysis, which quantifies the exergy destruction. Micro - gas turbines are prime movers that are ideally suited for cogeneration applications due to their flexibility in providing stable and reliable power. This paper presents an exergy analysis by means of a numerical simulation of a regenerative micro - gas turbine for cogeneration applications . The main objective is to study the best configuration of each system component , considering the minimization of the system irreversibilities . Each component of the system was evaluated considering the quantitative exergy balance . Subsequently the optimization procedure was applied to the mathematical model that describes the full system. The rate of irreversibility, efficiency and flaws are highlighted for each system component and for the whole system. The effect of turbine inlet temperature change on plant exergy destruction was also evaluated . The results disclose that considerable exergy destruction occurs in the combustion chamber. Also, it was revealed that the exergy efficiency is expressively dependent on the changes of the turbine inlet temperature and increases with the latter .The authors would like to express their acknowledgments for the support given by the Portuguese F01mdation for Science and Technology (FCT) through the PhD grant SFRH/BD/62287/2009. This work was financed by National Funds-Portuguese Foundation for Science and Technology, under Strategic Project and PEst-OE/EME/UI0252/2011 and also the PEst-C/EME/UI4077/2011

Biosurfactants: production, applications and future potential

Book of Abstracts of CEB Annual Meeting 2017[Excerpt] Surfactants are one of the most important classes of industrial chemicals in terms of production volume. These compounds exhibit a wide variety of applications in several industries and are present in nearly every product and aspect of our daily life. They can be found in detergents, laundry formulations, household cleaning products, cosmetics, herbicides or pesticides, and are also used in bioremediation, agriculture, food, pharmaceutical, textile, paper or the petroleum industries, among others. Most conventional surfactants available nowadays are derived from non-renewable resources and their use may lead to significant ecological problems due to their toxicity and low biodegradability. In the recent years, an increase in environmental awareness has led to much more interest in the use of renewablebased, biodegradable and more environmentally friendly surfactants. Among them biosurfactants, surface-active compounds synthesized by microorganisms, are attracting a pronounced interest due to their potential advantages over their synthetic counterparts, and to the fact that they could replace some of the synthetics in many environmental and industrial applications. [...]info:eu-repo/semantics/publishedVersio

Sodium chloride effect on the aggregation behaviour of rhamnolipids and their antifungal activity

In this work, the antifungal activity of rhamnolipids produced by Pseudomonas aeruginosa #112 was evaluated against Aspergillus niger MUM 92.13 and Aspergillus carbonarius MUM 05.18. It was demonstrated that the di-rhamnolipid congeners were responsible for the antifungal activity exhibited by the crude rhamnolipid mixture, whereas mono-rhamnolipids showed a weak inhibitory activity. Furthermore, in the presence of NaCl (from 375 mM to 875 mM), the antifungal activity of the crude rhamnolipid mixture and the purified di-rhamnolipids was considerably increased. Dynamic Light Scattering studies showed that the size of the structures formed by the rhamnolipids increased as the NaCl concentration increased, being this effect more pronounced in the case of di-rhamnolipids. These results were confirmed by Confocal Scanning Laser Microscopy, which revealed the formation of giant vesicle-like structures (in the µm range) by self-assembling of the crude rhamnolipid mixture in the presence of 875 mM NaCl. In the case of the purified mono- and di-rhamnolipids, spherical structures (also in the µm range) were observed at the same conditions. The results herein obtained demonstrated a direct relationship between the rhamnolipids antifungal activity and their aggregation behaviour, opening the possibility to improve their biological activities for application in different fields.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, COMPETE 2020 (POCI-01–0145-FEDER-006684) and the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462). The authors also acknowledge financial support from BioTecNorte operation (NORTE-01-0145-FEDER-000004) and the project MultiBiorefinery (POCI-01-0145-FEDER-016403) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. A. I. Rodrigues was supported by the doctoral Grant SFRH/111600/2015 provided by FCT. E. J. Gudiña was supported by the Post-Doctoral grant CEBBPD/01/2015/07 from the project UID/BIO/04469/2013, funded by FCT.info:eu-repo/semantics/publishedVersio

Seleção de fungos produtores de β-D-frutosiltransferase por fermentação em estado sólido

A enzima β-D-frutosiltransferase é responsável pela síntese de FOS (frutooligossacarídeos) a partir de sacarose por reação de transfrutosilação é produzida por diferentes micro-organismos, principalmente por fungos filamentosos. O objetivo deste trabalho foi selecionar a melhor linhagem fúngica produtora da -D-frutosiltransferase por fermentação em estado sólido, bem como o método de extração. A fermentação em estado sólido utilizando o substrato farelo de trigo umedecido com solução de sacarose atingindo 70% de umidade na concentração de esporos de 107 no tempo de 96 horas de crescimento. Todas as linhagens manipuladas apresentaram atividade hidrolítica, no entanto apenas uma linhagem não demonstrou atividade transfrutosilação. O isolado SIS 14 que pertence ao gênero Aspergillus sp. destacou-se pelos maiores valores em atividade no método de extração utilizando água destilada, apresentando 300,90 U/mL na atividade de transfrutosilação e na atividade hidrolítica de 155,74 U/mL. Contudo, pode-se perceber que dos solventes estudados a água destilada foi melhor obtendo o valor em atividade de transfrutosilação, como também a linhagem SIS 14 é promissora para a produção da β-D-frutosiltransferase

Balanced Scorecard as a management model in the waste sector

All Organizations recognize that internal methodologies and frameworks are very important to have a thorough knowledge of their potential, simultaneous increase competitiveness and, correspondingly, enhance and optimize the performance of their service. Waste management is a challenge of modern society, and there is awareness that responsibility of waste management should be shared by all community, to cooperate and ensure a sustainable development with the best principles and best management practices. It is a citizenship issue, where citizens contribute adopting preventative behaviours in the production of waste, as well as practices that facilitate waste recycling, reuse and recovery, which contribute to reduce the waste life cycle. This concern and the service improvement involve the minimization of the environmental impacts, the conservation of the natural resources, the reduction of pollutant emissions, as well as the design of the solutions for the collection, transfer and transport, treatment and waste final deposition, and the allocation of human and financial resources. The need for a sustainable management of resources has led to the design and development of management models in waste systems to assess in what extent the various tasks or activities are (or are not) carried out in accordance with the objectives established in advance and the efforts, decisions and operational actions developed by organisations to improve the quality of its work. Thus, given the problems and requirements of the waste sector, it is necessary to outline and plan sustainable strategies for the management system. Therefore, the objective of the present work is the application and study of key concepts related to design and implementation of a management model, the Balanced Scorecard (BSC). This is a management method based on critical success factors, which propose is to translate through a systemic approach, the mission and strategy of Organizations (private or public / nonprofit) in operational objectives, arranged into perspectives interconnected in a cause-effect relation. It connects the strategic objectives to measurable measures (performance indicators) that indicate the success or failure of the adopted strategy, contributing to a review. The BSC is a very useful and simple management tool, which perfectly suits the needs of the waste sector. It works as a measurement and management system, and a basis for the strategy communication to all elements of the system, and through a joint analysis, demonstrates of the importance of all stakeholders to the overall management, encouraging their involvement and motivation