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871.
872.
A. S. Palande S. V. Kulkarni C. León-Ramirez E. Campos-Góngora J. Ruiz-Herrera M. V. Deshpande 《Archives of microbiology》2014,196(8):545-556
Yarrowia lipolytica is able to metabolize high Mr hydrophobic natural compounds such as fatty acids and hydrocarbons. Characteristically, strains of Y. lipolytica can grow as populations with variable proportions of yeast and filamentous forms. In the present study, we describe the dimorphic characteristics of a variant designated as Y. lipolytica var. indica isolated from petroleum contaminated sea water and the effect of cell morphology on hydrocarbon metabolism. The variant behaved as a yeast monomorphic strain, under conditions at which terrestrial Y. lipolytica strain W29 and its derived strains, grow as almost uniform populations of mycelial cells. Using organic nitrogen sources and N-acetylglucosamine as carbon source, var. indica was able to form mycelial cells, the proportion of which increased when incubated under semi-anaerobic conditions. The cell surface characteristics of var. indica and W29 were found to be different with respect to contact angle and percent hydrophobicity. For instance, percent hydrophobicity of var. indica was 89.93 ± 1.95 while that of W29 was 70.78 ± 1.1. Furthermore, while all tested strains metabolize hydrocarbons, only var. indica was able to use it as a carbon source. Yeast cells of var. indica metabolized hexadecane with higher efficiency than the mycelial form, whereas the mycelial form of the terrestrial strain metabolized the hydrocarbon more efficiently, as occurred with the mycelial monomorphic mutant AC11, compared to the yeast monomorphic mutant AC1. 相似文献
873.
Data on biomass, production and metabolism of the biota, gathered during many years in the Rybinsk Reservoir, USSR, were used to calculate functional interconnections between separate components of the ecosystem, neglecting fluctuations of biomass and postulating a stationary state of the system.A matrix of interconnections was constructed and the influence of an increase or decrease of the biomass of one element upon all other elements of the ecosystem was calculated and discussed. 相似文献
874.
Summary Catalase in yeast cells is rendered thermolabile on permeabilization using organic solvents or any process of immobilization that eventually permeabilizes the cells. A stable immobilized catalase preparation can be obtained only if yeast cells are immobilized in an intact or viable form. 相似文献
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Christopher D. Wiley Rishi Sharma Sonnet S. Davis Jose Alberto Lopez-Dominguez Kylie P. Mitchell Samantha Wiley Fatouma Alimirah Dong Eun Kim Therese Payne Andrew Rosko Eliezer Aimontche Sharvari M. Deshpande Francesco Neri Chisaka Kuehnemann Marco Demaria Arvind Ramanathan Judith Campisi 《Cell metabolism》2021,33(6):1124-1136.e5
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pH-Dependence of hydrolytic activity of trypsin has been studied in cationic reverse micellar system of cetyltrimethylammonium bromide (CTAB) in (50% v/v) chloroform/isooctane using a positively charged substrate Nα-benzoyl-L-arginine ethyl ester (BAEE). The pH of the medium was varied from 4.0 to 8.5 with addition of 0.025 M citrate-phosphate buffer containing 1 mM CaCl2. Optimum pH for maximum enzyme activity, pHopt in reverse micelles is found to be similar to that observed in bulk aqueous solution (8.0–8.5). However, changes in activity of trypsin (kcat) as a function of water content W0 (W0 = [H2O]/[CTAB]) in reverse micelles are found to be pH dependent. At low pH (4.0) and low water content (W0 = 5) the enzyme is more active in reverse micelles than in bulk aqueous solution by a factor of 2. This ‘superactivity’ is lost at higher W0 values and the kcat in reverse micelles is found to be similar to that observed in aqueous bulk. At pH 5, the enzyme activity is found to be independent of W0 while at pH 6.0–6.5 the enzyme activity is low at W0 5 and increases with water content to a constant value which is still 50% lower than that in aqueous buffer. Above pH 7, the Wo-activity profile becomes distinctly bell shaped with W0 optimum around 10–15. The enzyme activity at optimum W0 is close to that observed in aqueous bulk. 相似文献