Person:
Guevara Acosta, Flor Govinda

Profile Picture
First Name
Flor Govinda
Last Name
Guevara Acosta
URI
https://hdl.handle.net/20.500.14352/74397
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Biológicas
Department
Bioquímica y Biología Molecular
Area
Identifiers
UCM identifierORCIDScopus Author IDWeb of Science ResearcherIDDialnet IDGoogle Scholar ID

Filters

2018 - 20194
Reset filters

Settings

End date: 2019 × Start date: 2018 ×

Search Results

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    Avances en el estudio de la enzimas implicadas en la ruta de degradación del anillo esteroideo en "Rodococcus ruber Chol-4"
    (2018) Guevara Acosta, Flor Govinda; Navarro Llorens, Juana María
    Rhodococcus ruber Chol-4 es una actinobacteria aislada a partir de una muestra de lodos de depuradora. Esta cepa es capaz de crecer en medio mínimo suplementado con esteroides y compuestos aromáticos, mostrando una gran capacidad catabólica. La degradación de compuestos aromáticos y esteroides ayuda a mantener el ciclo global del carbono, además de tener un número creciente de aplicaciones biotecnológicas que van desde la biodegradación de contaminantes hasta la producción de compuestos farmacéuticos. El género rhodococci contiene múltiples genes homólogos, lo que le confiere una amplia y versátil capacidad catabólica. Sin embargo, la redundancia de genes en los genomas actinobacterianos resulta una seria complicación para obtener intermediarios de interés industrial mediante ingeniería metabólica. La actividad de la enzima 3-cetosteroide-Δ1-deshidrogenasa (KstD) en combinación con la 3-cetosteroide-9α-hidroxilasa (KshAB) es clave en el esquema general del catabolismo bacteriano de esteroides, ambas son responsables de la rotura del núcleo esteroide A/B. KshAB inicia la apertura del anillo de esteroides mediante la 9α-hidroxilación del carbono C9 de 4-eno-3-oxosteroides (p. ej. AD) o 1,4-dieno-3-oxosteroides (p. ej. ADD), transformándolos en 9α-hidroxi-4-androsten-3,17-diona (9OHAD) o 9α-hidroxi-1,4-androstadien-3,17-diona (9OHADD), respectivamente. KstD convierte 4-eno-3-oxoesteroides (p. ej. AD) o 9-hidroxi-4-eno-3-oxoesteroides (p. ej. 9OH-AD) a 1,4-dieno-3-oxoesteroides (p. ej. ADD) o 9-hidroxi-1,4-dieno-3-oxoesteroides (p. ej. 9OH-ADD) por eliminación transaxial de los átomos de hidrógeno C-1 (α) y C-2 (β)...
  • Thumbnail Image
    Item
    Project number: 140
    Estrategias de flipped learning en fundamentos de ingeniería genética
    (2019) Navarro Llorens, Juana María; Lorente Pérez, María del Mar; Sánchez Torralba, Antonio; Blázquez Ortiz, Cristina; Ranz Valdecasa, María Regina; López Conejo, María Teresa; Guevara Acosta, Flor Govinda
    La asignatura de Fundamentos de Ingeniería genética del grado de Biología resulta muy árida en su actual formulación. Este proyecto pretende darle la vuelta para que sea el alumno quien construya el conocimiento y participe en el aprendizaje.
  • Thumbnail Image
    Item
    New insights into the genome of Rhodococcus ruber strain Chol-4
    (BMC Genomics, 2019) Guevara Acosta, Flor Govinda; Castillo López, María; Alonso, Sergio; Perera González, Julián; Navarro Llorens, Juana María
    Background: Rhodococcus ruber strain Chol-4, a strain isolated from a sewage sludge sample, is able to grow in minimal medium supplemented with several compounds, showing a broad catabolic capacity. We have previously determined its genome sequence but a more comprehensive study of their metabolic capacities was necessary to fully unravel its potential for biotechnological applications. Results: In this work, the genome of R. ruber strain Chol-4 has been re-sequenced, revised, annotated and compared to other bacterial genomes in order to investigate the metabolic capabilities of this microorganism. The analysis of the data suggests that R. ruber Chol-4 contains several putative metabolic clusters of biotechnological interest, particularly those involved on steroid and aromatic compounds catabolism. To demonstrate some of its putative metabolic abilities, R. ruber has been cultured in minimal media containing compounds belonging to several of the predicted metabolic pathways. Moreover, mutants were built to test the naphtalen and protocatechuate predicted catabolic gene clusters. Conclusions: The genomic analysis and experimental data presented in this work confirm the metabolic potential of R. ruber strain Chol-4. This strain is an interesting model bacterium due to its biodegradation capabilities. The results obtained in this work will facilitate the application of this strain as a biotechnological tool.
  • Thumbnail Image
    Item
    Metabolic engineering of Rhodococcus ruber Chol-4: A cell factory for testosterone production
    (Plos One, 2019) Guevara Acosta, Flor Govinda; Olortegui Flores, Yamileth; Fernández de las Heras, Laura; Perera González, Julián; Navarro Llorens, Juana María
    Rhodococcus ruber Chol-4 is a potent steroid degrader that has a great potential as a biotechnological tool. As proof of concept, this work presents testosterone production from 4- androstene-3,17-dione by tailoring innate catabolic enzymes of the steroid catabolism inside the strain. A R. ruber quadruple mutant was constructed in order to avoid the breakage of the steroid nucleus. At the same time, an inducible expression vector for this strain was developed. The 17-ketoreductase gene from the fungus Cochliobolus lunatus was cloned and overexpressed in this vector. The engineered strain was able to produce testosterone from 4-androstene-3,17-dione using glucose for cofactor regeneration with a molar conversion of 61%. It is important to note that 91% of the testosterone was secreted outside the cell after 3 days of cell biotransformation. The results support the idea that Rhodococcus ruber Chol-4 can be metabolically engineered and can be used for the production of steroid intermediates.