ABSTRACT
ABSTRACT Protoplasts are microbial or vegetable cells lacking a cell wall. These can be obtained from microalgae by an enzymatic hydrolysis process in the presence of an osmotic stabilizer. In general, protoplasts are experimentally useful in physiological, genetic and biochemical studies, so their acquisition and fusion will continue to be an active research area in modern biotechnology. The fusion of protoplasts in microalgae constitutes a tool for strain improvement because it allows both intra and interspecific genetic recombination, resulting in organisms with new or improved characteristics of industrial interest. In this review we briefly describe the methodology for obtaining protoplasts, as well as fusion methods and the main applications of microalgal platforms.
RESUMEN Los protoplastos son células microbianas o vegetales que carecen de pared celular. Estos pueden obtenerse a partir de microalgas por un proceso de hidrólisis enzimática en presencia de un estabilizador osmótico. En general, los protoplastos son experimentalmente útiles en estudios fisiológicos, genéticos y bioquímicos, por lo que su obtención y fusión continuarán siendo un área de investigación activa en la biotecnología moderna. La fusión de protoplastos en microalgas constituye una herramienta para el mejoramiento de cepas pues permite la recombinación genética intra e interespecífica, logrando así organismos con nuevas características de interés industrial. En esta revisión, describimos brevemente la metodología para obtener protoplastos, métodos de fusión y las principales aplicaciones de las plataformas basadas en microalgas.
ABSTRACT
Brewer's yeast is crucial in beer fermentation, mainly beer flavor diversity and stability. Beer flavor stability is one of the most influential beer quality aspects, and screening or breeding brewer's yeast with enhanced anti-staling capacity will be an effective solution. In recent decades, with the progress of genetic engineering and detailed description of brewer's yeast genome, great efforts have been made to improve brewer's yeast. This review highlights recent advances in classical and genetic engineering improvement of yeasts to produce more antioxidant compounds or less beer aging substances and precursors. Therein, improvement targets, evaluation methods and development strategies of anti-staling brewer's yeast are also discussed. Furthermore, hotspot and future trend of anti-staling yeast strain development are also proposed.
ABSTRACT
The aim of the present study is to optimize the growth conditions for improved production of alkaloids by promising marine actinomycetes isolated from marine sediments collected on Kakinada coast. The bioactive compounds were extracted from the isolated actinomycete using organic solvents and screened for alkaloids using qualitative tests. The presence of alkaloids in the crude methanol extract was confirmed by UV spectroscopic analysis and quantified by BCG method. The effect of pH, temperature, carbon and nitrogen sources on the growth and fermentative production of alkaloids was optimized. The strain was improved for enhanced production of alkaloids by physical and chemical mutagenesis. The antimicrobial activity of the crude alkaloid extract was determined by the well diffusion method. The isolated strain exhibited the highest growth and alkaloid production at pH 6 and temperature 30oC in 7 days. The alkaloid production was significantly increased 4.5-folds with UV treatment for 30 min and further, 5.5-folds with ethidium bromide treatment(30µg/mL) for 1hr. The resultant double mutant strain exhibited significantly high antimicrobial activity against S. aureus compared to other bacterial strains with MIC index less than 4. The isolated double mutant strain of actinomycetes can be a potential source of antibiotic alkaloids.