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排序方式: 共有615条查询结果,搜索用时 15 毫秒
101.
The purpose of this study was to evaluate the evolution of lactic acid bacteria (LAB) and yeasts during the fermentation of tarhana produced with some pasteurised ingredients and carried out at 30 and 40 °C. The chemical parameters were those typical for tarhana production. Coliform bacteria were not detected during fermentation, while LAB and yeasts were in the range 107-108 colony forming units (CFU) g−1. Plate counts showed an optimal development of both fermenting microbial groups and the differences in cell concentrations were not significant (P > 0.05). LAB were isolated during fermentation and grouped on the basis of phenotypic and polymorphic characteristics. LAB isolates were identified by a combined genetic approach consisting of 16S/23S rRNA intergenic spacer region (ITS) and partial 16S rRNA gene sequencing as Pediococcus acidilactici, Lactobacillus plantarum and Lactobacillus brevis. Hence, the pasteurisation of the vegetable ingredients, excluded wheat flour, enhanced the hygienic conditions of tarhana without influencing the normal evolution of LAB. However, the fermentation at 40 °C favoured pediococci, while the production at 30 °C was mainly characterised by lactobacilli. Yeasts, identified by the restriction fragment length polymorphism (RFLP) of the 5.8S ITS rRNA gene, were mainly represented by the species Saccharomyces cerevisiae in both productions. 相似文献
102.
Phenotypic and genotypic characterization of Oenococcus oeni strains isolated from Italian wines 总被引:3,自引:0,他引:3
Guerrini S Bastianini A Blaiotta G Granchi L Moschetti G Coppola S Romano P Vincenzini M 《International journal of food microbiology》2003,83(1):1-14
A phenotypic and genotypic characterization of 84 Oenococcus oeni isolates from Italian wines of different oenological areas was carried out. Numerical analysis of fatty acid profiles grouped the isolates into two clusters at low level of similarity (63%), the minor cluster containing seven isolates besides the type and the reference strains. Forthy-eight O. oeni isolates, representative of the two clusters, showed no differences in their metabolic properties (heterolactic fermentation pattern, citrate degradation capability and formation of some secondary metabolites). Moreover, the analysis of species-specific randomly amplified polymorphic DNA and 16S-23S rDNA intergenic spacer region polymorphism as well as the sequence-specific separation of V3 region from 16S rDNA by denaturing gradient gel electrophoresis demonstrated a substantial homogeneity among the isolates. On the basis of ApaI Pulsed Field Gel Electrophoresis (PFGE) restriction patterns, the 84 isolates were grouped into five different clusters at 70% similarity, but no correlation with the phenotypic groups could be demonstrated. However, by combining phenotypic and genotypic data, the 84 O. oeni isolates grouped into eight phenotypic-genotypic combined profiles and a relationship between the origin of the isolates and their combined profile became evident, so that a sort of strain specificity can be envisaged for each wine-producing area. 相似文献
103.
Mariotti Ilaria Barzotto Mariachiara Cor Giancarlo Saloriani Stefano 《The Annals of Regional Science》2020,64(3):523-546
The Annals of Regional Science - The present paper aims at exploring the location behaviour of manufacturing firms, according to their ownership: domestic firms (henceforth DOMs) and inward foreign... 相似文献
104.
Stefania Galdiero Annarita Falanga Marco Cantisani Mariateresa Vitiello Giancarlo Morelli Massimiliano Galdiero 《International journal of molecular sciences》2013,14(9):18758-18789
The interactions between peptides and lipids are of fundamental importance in the functioning of numerous membrane-mediated cellular processes including antimicrobial peptide action, hormone-receptor interactions, drug bioavailability across the blood-brain barrier and viral fusion processes. Moreover, a major goal of modern biotechnology is obtaining new potent pharmaceutical agents whose biological action is dependent on the binding of peptides to lipid-bilayers. Several issues need to be addressed such as secondary structure, orientation, oligomerization and localization inside the membrane. At the same time, the structural effects which the peptides cause on the lipid bilayer are important for the interactions and need to be elucidated. The structural characterization of membrane active peptides in membranes is a harsh experimental challenge. It is in fact accepted that no single experimental technique can give a complete structural picture of the interaction, but rather a combination of different techniques is necessary. 相似文献
105.
Jens Theuerkauf Giancarlo Franci Walter Leitner 《Advanced Synthesis \u0026amp; Catalysis》2013,355(1):209-219
A continuous‐flow process for the asymmetric hydrogenation of methyl propionylacetate as a prototypical β‐keto ester in a biphasic system of ionic liquid and supercritical carbon dioxide (scCO2) is presented. An established ruthenium/2,2′‐bis(diphenylphosphino)‐1,1′‐binaphthyl (BINAP) catalyst was immobilised in an imidazolium‐based ionic liquid while scCO2 was used as mobile phase transporting reactants in and products out of the reactor. The use of acidic additives led to significantly higher reaction rates and enhanced catalyst stability albeit at slightly reduced enantioselectivity. High single pass conversions (>90%) and good enantioselectivity (80–82% ee) were achieved in the first 80 h. The initial catalyst activity was retained to 91% after 100 h and to 69% after 150 h time‐on‐stream, whereas the enantioselectivity remained practically constant during the entire process. A total turnover number of ∼21,000 and an averaged space‐time yield (STYav) of 149 g L−1 h−1 were reached in a long‐term experiment. No ruthenium and phosphorus contaminants could be detected via inductively coupled plasma optical emission spectrometry (ICP‐OES) in the product stream and almost quantitative retention by the analysis of the stationary phase was confirmed. A comparison between batch‐wise and continuous‐flow operation on the basis of these data is provided. 相似文献
106.
Kieran P. Donaghy Daniela Federici Giancarlo Gandolfo 《The Annals of Regional Science》2001,35(3):449-461
Most recent theoretical research on endogenous economic growth has been conducted with continuous-time models that embody
the assumption of an intertemporally optimizing representative agent. Yet virtually none of these models has been confronted
with empirical data. In this paper we make use of a model of an open economy recently developed by Turnovsky to demonstrate
one approach to the estimation and analysis of such models. We present the results of the estimation, analyze the estimated
model's stability properties around its steady-state solution, and explore the model's behavior in response to alternative
tax policies. 相似文献
107.
108.
Ianni Michele Masciari Elio Sperlí Giancarlo 《Journal of Intelligent Information Systems》2021,57(1):73-100
Journal of Intelligent Information Systems - The pervasive diffusion of Social Networks (SN) produced an unprecedented amount of heterogeneous data. Thus, traditional approaches quickly became... 相似文献
109.
Reordering schemes associated with multicoloring and domain decomposition techniques have been introduced in recent years to obtain parallel and/or vectorized versions of recursive linear solvers such as the Gauss-Seidel SOR scheme (Ortega and Voigt, 1986; White, 1989). In this paper we give a brief account of the successfull implementation of a four-color Gauss-Seidel parallel algorithm for the solution of block-tridiagonal matrices resulting from the finite-element discretization of a two-dimensional advection-diffusion equation. Performance data referring to the implementation on the IBM 3090/400 vector multiprocessor are reported and commented on. 相似文献
110.