Mixing and mass transfer in shake flasks and their relationship with antibodies productivity of CHO cells

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Del editor - el uso de biorreactores desechables en la industria biofarmacéutica y sus implicaciones en la ingeniería

En la industria biofarmacéutica actual, los requerimientos para el diseño de un biorreactor difieren sustancialmente de aquellos de hace 50 años. Hoy en día las nuevas estrategias de cultivo permiten obtener alta densidad celular con altos rendimientos de productos biotecnológicos que deben cumplir con elevados estándares de calidad y normatividad compleja en su producción. Lo anterior obliga el desarrollo de nuevas tecnologías para suplir estas necesidades, por lo que en los últimos diez años el diseño y uso de biorreactores desechables ha crecido de manera exponencial. Los beneficios de la tecnología desechable son principalmente la eliminación de largos procesos de limpieza, esterilización, calificación, validación, reducción de tiempo entre lotes, el procesamiento de diferentes productos en la misma área, entre otros, lo que conlleva la disminución de los costos que implican esta serie de procedimientos

Significado psicológico de México entre niños

El objetivo del trabajo fue detectar el significado psicológico de "México" en niñas y niños. Se trabajó con 60 estudiantes de Primaria, repartidos equitativamente por género, con edades entre nueve y once años. Se utilizó la técnica original de redes semánticas naturales para obtener la información referente al significado psicológico de México. Las aplicaciones se hicieron de forma grupal en los salones de clase. Los resultados dejan ver que entre los participantes hubo una definición muy favorable de México, en la que los niños orientaron sus respuestas hacia los aspectos políticos, en comparación con las niñas, que definieron a México con base en sus bellezas naturales y las características afectivas de sus habitantes. Se observó que prevalece una tendencia instrumental en el género masculino, en contraste con la de tipo afectivo y expresivo del género femenino, rasgos propios de la cultura mexicana desde mucho tiempo atrás, que al parecer no registran cambios trascendentales en los papeles o roles asignados para cada uno de los géneros en México

Production of recombinant proteins in E. coli by the heat inducible expression system based on the phage lambda pL and/or pR promoters

The temperature inducible expression system, based on the pL and/or pR phage lambda promoters regulated by the thermolabile cI857 repressor has been widely use to produce recombinant proteins in prokariotic cells. In this expression system, induction of heterologous protein is achieved by increasing the culture temperature, generally above 37°C. Concomitant to the overexpression of heterologous protein, the increase in temperature also causes a variety of complex stress responses. Many studies have reported the use of such temperature inducible expression system, however only few discuss the simultaneous stress effects caused by recombinant protein production and the up-shift in temperature. Understanding the integral effect of such responses should be useful to develop improved strategies for high yield protein production and recovery. Here, we describe the current status of the heat inducible expression system based on the pL and/or pR λ phage promoters, focusing on recent developments on expression vehicles, the stress responses at the molecular and physiological level that occur after heat induction, and bioprocessing factors that affect protein overexpression, including culture operation variables and induction strategies

Subcellular fractionation coupled to shotgun proteomics allows the identification of novel targets of the classical secretion pathway associated with increased productivity in recombinant CHO cells

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Simultaneous genetic engineering and culture media manipulation improve rh-EPO productivity through lactate re-metabolization on CHO cell culture

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The O-mannosylation and production of recombinant APA (45/47 KDa) protein from Mycobacterium tuberculosis in Streptomyces lividans is affected by culture conditions in shake flasks

<p>Abstract</p> <p>Background</p> <p>The Ala-Pro-rich <it>O</it>-glycoprotein known as the 45/47 kDa or APA antigen from <it>Mycobacterium tuberculosis </it>is an immunodominant adhesin restricted to mycobacterium genus and has been proposed as an alternative candidate to generate a new vaccine against tuberculosis or for diagnosis kits. In this work, the recombinant <it>O</it>-glycoprotein APA was produced by the non-pathogenic filamentous bacteria <it>Streptomyces lividans</it>, evaluating three different culture conditions. This strain is known for its ability to produce heterologous proteins in a shorter time compared to <it>M. tuberculosis</it>.</p> <p>Results</p> <p>Three different shake flask geometries were used to provide different shear and oxygenation conditions; and the impact of those conditions on the morphology of <it>S. lividans </it>and the production of rAPA was characterized and evaluated. Small unbranched free filaments and mycelial clumps were found in baffled and coiled shake flasks, but one order of magnitude larger pellets were found in conventional shake flasks. The production of rAPA is around 3 times higher in small mycelia than in larger pellets, most probably due to difficulties in mass transfer inside pellets. Moreover, there are four putative sites of <it>O</it>-mannosylation in native APA, one of which is located at the carboxy-terminal region. The carbohydrate composition of this site was determined for rAPA by mass spectrometry analysis, and was found to contain different glycoforms depending on culture conditions. Up to two mannoses residues were found in cultures carried out in conventional shake flasks, and up to five mannoses residues were determined in coiled and baffled shake flasks.</p> <p>Conclusions</p> <p>The shear and/or oxygenation parameters determine the bacterial morphology, the productivity, and the <it>O</it>-mannosylation of rAPA in <it>S. lividans</it>. As demonstrated here, culture conditions have to be carefully controlled in order to obtain recombinant <it>O</it>-glycosylated proteins with similar "quality" in bacteria, particularly, if the protein activity depends on the glycosylation pattern. Furthermore, it will be an interesting exercise to determine the effect of shear and oxygen in shake flasks, to obtain evidences that may be useful in scaling-up these processes to bioreactors. Another approach will be using lab-scale bioreactors under well-controlled conditions, and study the impact of those on rAPA productivity and quality.</p

Teaching bioreactors operation and scale-up of bioprocesses: Multidisciplinary training in a theoretical-practical course of one week

La biotecnología es un área emergente y prioritaria para países en vías de desarrollo. Los biorreactores son un equipo fundamental y se convierten en un elemento clave para el desarrollo e innovación en bioprocesos. El conocimiento de estos equipos es fundamental para lograr el crecimiento y desarrollo de microorganismos, células animales y vegetales, e inclusive la micropropagación de plantas. En una iniciativa conjunta por parte de los autores de este artículo y con el apoyo de las respectivas instituciones académicas, desde 2012 el Curso Internacional “Escalado de Bioprocesos y Entrenamiento en Operación de Biorreactores” se ha realizado por siete ocasiones. El objetivo del curso es ofrecer a la comunidad científica de Iberoamérica un entrenamiento Teórico - Práctico en bioprocesos. Producto de este curso, se ha capacitado a más de 1400 personas a través de conferencias y a 216 personas con las habilidades prácticas en el laboratorio. El curso ha permitido fomentar una red de contactos que operan en la consultoría y en la movilidad de personas. Además, uno de los productos destacados es la integración de un libro, que contribuye como una obra de consulta en el tema.Biotechnology is an emerging and priority area for developing countries. Bioreactors are essential equipment and a key element for development and innovation in bioprocesses. The knowledge of this equipment is essential to achieve the growth of microorganisms, animal and plant cells, and even the micropropagation of plants. In a joint initiative by the authors of this article, and with the support of the respective academic institutions, the International Course “Bioprocess Scaling and Training in Bioreactor Operation” has been held seven times since 2012. The objective of this course is to offer to the Latin American scientific community a theoretical and practical training in bioprocesses. As a result of this course, more than 1400 people have been trained through lectures and 216 people with practical skills in the laboratory. The course has promoted a network of contacts that operate in consulting and people mobility. In addition to the fact that one of the outstanding products is the integration of a book.Fil: Trujillo Roldán, Mauricio A.. Universidad Nacional Autónoma de México; MéxicoFil: Orozco Sánchez, Fernando. Universidad Nacional de Colombia. Sede Medellín; ColombiaFil: Valdez Cruz, Norma A.. Universidad Nacional Autónoma de México; MéxicoFil: Rodríguez Monroy, Mario. Instituto Politécnico Nacional. Centro de Desarrollo de Productos Bióticos; MéxicoFil: Busto, Víctor Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Nanobiotecnología. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología; Argentin

Bacterial inclusion bodies are industrially exploitable amyloids

Understanding the structure, functionalities and biology of functional amyloids is an issue of emerging interest. Inclusion bodies, namely protein clusters formed in recombinant bacteria during protein production processes, have emerged as unanticipated, highly tunable models for the scrutiny of the physiology and architecture of functional amyloids. Based on an amyloidal skeleton combined with varying amounts of native or native-like protein forms, bacterial inclusion bodies exhibit an unusual arrangement that confers mechanical stability, biological activity and conditional protein release, being thus exploitable as versatile biomaterials. The applicability of inclusion bodies in biotechnology as enriched sources of protein and reusable catalysts, and in biomedicine as biocompatible topographies, nanopills or mimetics of endocrine secretory granules has been largely validated. Beyond these uses, the dissection of how recombinant bacteria manage the aggregation of functional protein species into structures of highly variable complexity offers insights about unsuspected connections between protein quality (conformational status compatible with functionality) and cell physiology.info:eu-repo/semantics/acceptedVersio