RESUMO
BACKGROUND: Low-temperature expression of recombinant proteins may be advantageous to support their proper folding and preserve bioactivity. The generation of expression vectors regulated under cold conditions can improve the expression of some target proteins that are difficult to express in different expression systems. The cspA encodes the major cold-shock protein from Escherichia coli (CspA). The promoter of cspA has been widely used to develop cold shock-inducible expression platforms in E. coli. Moreover, it is often necessary to employ expression systems other than bacteria, particularly when recombinant proteins require complex post-translational modifications. Currently, there are no commercial platforms available for expressing target genes by cold shock in eukaryotic cells. Consequently, genetic elements that respond to cold shock offer the possibility of developing novel cold-inducible expression platforms, particularly suitable for yeasts, and mammalian cells. CONCLUSIONS: This review covers the importance of the cellular response to low temperatures and the prospective use of cold-sensitive promoters to direct the expression of recombinant proteins. This concept may contribute to renewing interest in applying white technologies to produce recombinant proteins that are difficult to express.
RESUMO
Endophytes, microorganisms that live in the internal tissues and organs of the plants, are known to produce numerous bioactive compounds, including, at times, some phytochemicals of their host plant. For such reason, endophytes have been quoted as a potential source for discovering bioactive compounds, particularly, of medical interest. Currently, many non-communicable diseases are threatening global human health, noticeably: diabetes, neurodegenerative diseases, cancer, and other ailment related to chronic inflammation and ageing. Intriguingly, the pathogenesis and development of these diseases have been linked to an excessive formation and accumulation of advanced glycation end products (AGEs). AGEs are a heterogeneous group of compounds that can alter the conformation, function, and lifetime of proteins. Therefore, compounds that prevent the formation and consequent accumulation of AGEs (AntiAGEs compounds) could be useful to delay the progress of some chronic diseases, and/or harmful effects of undue AGEs accumulation. Despite the remarkable ability of endophytes to produce bioactive compounds, most of the natural antiAGEs compounds reported in the literature are derived from plants. Accordingly, this work covers 26 plant antiAGEs compounds and some derivatives that have been reported as endophytic metabolites, and discusses the importance, possible advantages, and challenges of using endophytes as a potential source of antiAGEs compounds.
Assuntos
Endófitos , Produtos Finais de Glicação Avançada , Endófitos/química , Fungos/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Humanos , Compostos Fitoquímicos/metabolismo , Plantas/químicaRESUMO
Cr(VI) removal by Scenedesmus incrassatulus was characterized in a continuous culture system using a split-cylinder internal-loop airlift photobioreactor fed continuously with a synthetic effluent containing 1.0mg Cr(VI) l(-1) at dilution rate (D) of 0.3d (-1). At steady state, there was a small increase (6%) on the dry biomass (DB) concentration of Cr(VI)-treated cultures compared with the control culture. 1.0mg Cr(VI) l(-1) reduced the photosynthetic pigments content and altered the cellular morphology, the gain in dry weight was not affected. At steady state, Cr(VI) removal efficiency was 43.5+/-1.0% and Cr(VI) uptake was 1.7+/-0.1 mg Cr(VI) g(-1) DB. The system reached a specific metal removal rate of 458 microg Cr(VI) g(-1) DB d(-1), and a volumetric removal rate of 132 microg Cr(VI) l(-1) d(-1).
Assuntos
Reatores Biológicos , Cromo/isolamento & purificação , Luz , Scenedesmus/metabolismo , Scenedesmus/efeitos da radiação , Biodegradação Ambiental/efeitos da radiação , Biomassa , Fotossíntese/efeitos da radiação , Pigmentos Biológicos/metabolismoRESUMO
Durante la década pasada se han usado múltiples diseños de fotobiorreactores para el cultivo de organismos fotoautróficos microscópicos como microalgas y cianobacterias. Los avances en el diseño de estos sistemas han permitido mejorar notablemente la densidad celular, la productividad y por ende la economía de los cultivos para distintos fines. En este trabajo se revisan diferentes aspectos del diseño de fotobiorreactores, tanto aquellos que implican el aprovechamiento adecuado de la energía luminosa (ciclos luz-oscuridad, trayectoria de la luz y geometría de fotobiorreactores) como los basados en conceptos fisiológicos (fotoinhibición por oxígeno, cultivos de alta densidad celular, ultra alta densidad celular, heterotrofía y mixotrofía). Se presentan las principales aplicaciones de los diferentes diseños, en la producción de compuestos de alto valor agregado y su uso potencial en la biotecnología ambiental