Cancer is the second leading cause of death in the world and colorectal cancer is the only cancer... more Cancer is the second leading cause of death in the world and colorectal cancer is the only cancer that has shown a sustained increase in mortality in the last decade. In the search for new chemotherapeutic agents against cancer, extremophilic microorganisms have shown to be a potential source to obtain molecules of natural origin and with selective cytotoxic action towards cancer cells. In this work we analyzed the ability of a collection of Antarctic soil bacteria, isolated on Collins Glacier from the rhizosphere of Deschampsia antarctica Desv plant, to secrete molecules capable of inhibiting cell proliferation of a colorectal cancer tumor line. Our results demonstrated that culture supernatants from the Antarctic bacteria K2I17 and MI12 decreased the viability of LoVo cells, a colorectal adenocarcinoma cell line. Phenotypic and genotypic characterization of the Antarctic bacteria showed that they were taxonomically related and nucleotide identity analysis based on the 16S rRNA gene sequence identified the bacterium K2I17 as a species belonging to the genus Bacillus.
En este estudio 50 aislados bacterianos obtenidos de muestras de suelo antártico prístino, de las... more En este estudio 50 aislados bacterianos obtenidos de muestras de suelo antártico prístino, de las islas Rey George y Greenwich (Islas Shetland del Sur), y 25 aislados bacterianos de la rizósfera de Deschampsia antarctica Desv, se emplearon para determinar su capacidad antimicrobiana y su respuesta a 21 antibióticos. La susceptibilidad a los antibióticos se evaluó siguiendo el método de difusión en disco utilizando diferentes grupos de antibióticos: penicilinas, cefalosporinas, carbapenémicos, aminoglicósidos, quinolonas, tetraciclina, fenicoles, macrólidos, sulfonamidas y trimetoprim. La producción de compuestos antimicrobianos por los aislados bacterianos antárticos se determinó mediante el método de difusión en agar, utilizando como indicadores un panel de bacterias patógenas humanas Gram positivo y Gram negativo. Los aislados bacterianos estudiados mostraron resistencia a 14 (67%) de los 21 antibióticos probados. Tres aislados bacterianos (4%) fueron resistentes a al menos un ant...
Evaluation Results of the First Training Program on Engineering Pedagogy in Chilean Universities
This paper presents the results of a survey focused on the evaluation of an academic training cou... more This paper presents the results of a survey focused on the evaluation of an academic training course related to the different pedagogical aspects that influence the training of engineers seeking to improve the quality of teaching and the academic training in the engineering faculties of three Chilean universities (Universidad Autonoma de Chile, Universidad de Magallanes and Universidad de Talca). The training course consists in six modules according to the curricula of the training program “INTERNATIONAL ENGINEERING EDUCATOR ING.PAED.IGIP” of the IGIP center at the TU Dresden, Faculty of Education. The course was offered in blended learning modality with participation of academics from different regions of Chile (Concepcion, Punta Arenas, Santiago, Talca y Temuco). This training program was developed and implemented within the framework of the project “Engineering Didactics at Chilean Universities” (PEDING-Project). The aim of the PEDING-Project was the development and testing of tr...
La disminución sostenida de la disponibilidad de nuevas moléculas antimicrobianas para el uso ter... more La disminución sostenida de la disponibilidad de nuevas moléculas antimicrobianas para el uso terapéutico en las últimas décadas y el gran aumento de microorganismos resistentes a estos compuestos hace necesario buscar nuevas sustancias con propiedades antimicrobianas. Los ambientes extremos, donde hay poca disponibilidad de nutrientes, son escenarios propicios para buscar este tipo de compuestos, ya que las bacterias compiten entre sí y con otros organismos por posicionarse en el nicho ecológico y secretan, asociado a su metabolismo secundario, una serie de moléculas que inhiben o matan a otros microorganismos, evitando su multiplicación. Nuestro grupo posee una colección de bacterias aisladas de la rizósfera de suelo del continente antártico, que logran crecer en condiciones de deprivación alimenticia y a 4 ºC. Debido al hábitat extremo donde se desarrollan, las bacterias de los suelos de la Antártica están en una constante competencia por lo recursos nutricionales, desarrollando ...
Carotenoids are highly important in pigmentation, and its content in farmed crustaceans and fish ... more Carotenoids are highly important in pigmentation, and its content in farmed crustaceans and fish correlates to their market value. These pigments also have a nutritional role in aquaculture where they are routinely added as a marine animal food supplement to ensure fish development and health. However, there is little information about carotenoids obtained from Antarctic bacteria and its use for pigmentation improvement and flesh quality in aquaculture. This study identified carotenoids produced by Antarctic soil bacteria. The pigmented strain (CN7) was isolated on modified Luria–Bertani (LB) media and incubated at 4 °C. This Gram-negative bacillus was identified by 16S rRNA analysis as Flavobacterium segetis. Pigment extract characterization was performed through high-performance liquid chromatography (HPLC) and identification with liquid chromatography–mass spectrometry (LC–MS). HPLC analyses revealed that this bacterium produces several pigments in the carotenoid absorption range...
Estudios preliminares de la oxidación crómica de D-glucitol
Fil: Calisto, Nnacy Cristina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquimicas y... more Fil: Calisto, Nnacy Cristina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquimicas y Farmaceuticas. Area Inorganica. Departamento de Quimica Fisica; Argentina.
Evaluation Results of the First Training Program on Engineering Pedagogy in Chilean Universities
This paper presents the results of a survey focused on the evaluation of an academic training cou... more This paper presents the results of a survey focused on the evaluation of an academic training course related to the different pedagogical aspects that influence the training of engineers seeking to improve the quality of teaching and the academic training in the engineering faculties of three Chilean universities (Universidad Autonoma de Chile, Universidad de Magallanes and Universidad de Talca). The training course consists in six modules according to the curricula of the training program “INTERNATIONAL ENGINEERING EDUCATOR ING.PAED.IGIP” of the IGIP center at the TU Dresden, Faculty of Education. The course was offered in blended learning modality with participation of academics from different regions of Chile (Concepcion, Punta Arenas, Santiago, Talca y Temuco). This training program was developed and implemented within the framework of the project “Engineering Didactics at Chilean Universities” (PEDING-Project). The aim of the PEDING-Project was the development and testing of tr...
The kinetics of the reduction of chromium(VI) to chromium(III) by D-fructose in HClO 4 was studie... more The kinetics of the reduction of chromium(VI) to chromium(III) by D-fructose in HClO 4 was studied at various concentrations of reactants and acidities. The redox reaction takes place through a complex multistep mechanism, which involves the formation of intermediate Cr IV and Cr V species. Cr IV reacts with D-fructose much faster than Cr V and Cr VI do, and cannot be directly detected. Superoxochromium(III), CrO 2 2þ , has been detected by UV spectroscopy, thus evidencing that Cr II is an intermediary in these reactions and provides indirect evidence for the intermediary of Cr IV reaction path. The complete rate law for the Cr VI oxidation reaction is expressed by Àd[Cr VI ]/dt = (a + b [D-Fru])[H + ] 2 [Cr VI ] T , where a = (1.66 ± 0.04) • 10 À4 M À2 s À1 and b = (1.79 ± 0.06) • 10 À2 M À3 s À1. The EPR spectra show that five-coordinate oxo-Cr V bischelates are formed in rapid pre-equilibria before the redox step: Cr(V) to Cr(III).
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