During the industrial fermentation process in the production of fuel ethanol, yeasts are subject to several stressing conditions. The survival and the permanence of strains introduced in the process correlate with the...During the industrial fermentation process in the production of fuel ethanol, yeasts are subject to several stressing conditions. The survival and the permanence of strains introduced in the process correlate with the capability of these yeasts in resisting to physical and chemical stresses, as well as their recovering ability to compete with contaminating micro-organisms commonly present in this industrial process. We aim at the selection of Saccharomyces cere visiae strains having this capability and ability. In this sense, cultivations of strains with industrial interest were irradiated with gammas ray at a wide dose interval. Growing curves for the strains were analyzed by means of their relative growth, a new concept here introduced, which allows a better understanding of the growing and recovering processes following radiative stress. It was found that gamma radiation could be used as an alternative method to quantify growing capabilities of S. cerevisiae strains under stressing conditions. It was also shown that this radiological method could be utilized as an additional procedure to select best robust industrial strains. This radiological method simplifies traditional analysis of strain viability, by avoiding the great number of necessary and consecutive fermentation assays.展开更多
A new idea on how to conceptually interpret the so-called Taylor’s power law for ecological communities is presented. The core of our approach is based on nonextensive/nonlinear statistical concepts, which are shown ...A new idea on how to conceptually interpret the so-called Taylor’s power law for ecological communities is presented. The core of our approach is based on nonextensive/nonlinear statistical concepts, which are shown to be at the genesis of all power laws, particularly when a system is constituted by long-range interacting elements. In this context, the ubiquity of the Taylor’s power law is discussed and addressed by showing that long-range interactions are at the heart of the internal dynamics of populations.展开更多
A model based on Watson’s power law for the species-area relationship predicts that full global warming, projected up to the year 2050, could provoke the disappearance of roughly one-quarter of existing species. Here...A model based on Watson’s power law for the species-area relationship predicts that full global warming, projected up to the year 2050, could provoke the disappearance of roughly one-quarter of existing species. Here, an alternative approach is worked out, based on the combination of two ecology laws: Taylor and Watson’s power laws, where the former relates species variability with their mean abundance. Just how severely global warming would affect not only the number but the diversity of the surviving species is addressed by this approach, while at the same time giving indications for the post-disaster fate of the remaining species (extinction or recovery).展开更多
文摘During the industrial fermentation process in the production of fuel ethanol, yeasts are subject to several stressing conditions. The survival and the permanence of strains introduced in the process correlate with the capability of these yeasts in resisting to physical and chemical stresses, as well as their recovering ability to compete with contaminating micro-organisms commonly present in this industrial process. We aim at the selection of Saccharomyces cere visiae strains having this capability and ability. In this sense, cultivations of strains with industrial interest were irradiated with gammas ray at a wide dose interval. Growing curves for the strains were analyzed by means of their relative growth, a new concept here introduced, which allows a better understanding of the growing and recovering processes following radiative stress. It was found that gamma radiation could be used as an alternative method to quantify growing capabilities of S. cerevisiae strains under stressing conditions. It was also shown that this radiological method could be utilized as an additional procedure to select best robust industrial strains. This radiological method simplifies traditional analysis of strain viability, by avoiding the great number of necessary and consecutive fermentation assays.
基金supported by grants from FAPESP,CAPES and CNPq,Brazilian funding agencies for the promotion of science.
文摘A new idea on how to conceptually interpret the so-called Taylor’s power law for ecological communities is presented. The core of our approach is based on nonextensive/nonlinear statistical concepts, which are shown to be at the genesis of all power laws, particularly when a system is constituted by long-range interacting elements. In this context, the ubiquity of the Taylor’s power law is discussed and addressed by showing that long-range interactions are at the heart of the internal dynamics of populations.
基金supported by grants from FAPESP,CNEN and CNPq,Brazilian funding agencies for the promotion of science.
文摘A model based on Watson’s power law for the species-area relationship predicts that full global warming, projected up to the year 2050, could provoke the disappearance of roughly one-quarter of existing species. Here, an alternative approach is worked out, based on the combination of two ecology laws: Taylor and Watson’s power laws, where the former relates species variability with their mean abundance. Just how severely global warming would affect not only the number but the diversity of the surviving species is addressed by this approach, while at the same time giving indications for the post-disaster fate of the remaining species (extinction or recovery).
