1,721,495 research outputs found
Kinetic characteristics of β-cyclodextrin production by cyclodextrin glycosyltransferase from newly isolated Bacillus sp. C26
No full textThe kinetic characteristics of β-cyclodextrin production by a cyclodextrin glycosyltransferase (CGTase) produced by Bacillus sp. C26, a new isolate from a soil sample was investigated. Considering highest yield and initial production rate of β-cyclodextrin, among the starches examined, soluble starch, tapioca starch, sago starch, corn starch and rice starch, tapioca starch was the best substrate for this CGTase. The optimum temperature for tapioca starch gelatinization prior to its use as a substrate for β-cyclodextrin production was 65ºC. The yield and initial production rate of β-cyclodextrin increased with increasing starch concentration up to 6% and an enzyme concentration up to 48 U/g-starch. The kinetic parameters of Vmax and Km of β-cyclodextrin production from tapioca starch by CGTase were 1.59 mg/mL/h and 22.3 mg/mL, respectively. Considering high initial production rate and high yield of β-cyclodextrin, the optimum reaction temperature was at 50ºC. This study provided the necessary kinetic information that may be useful to define the most suitable condition for industrialized production ofβ-cyclodextrin with the high yield and productivity
Kinetic characteristics of β-cyclodextrin production by cyclodextrin glycosyltransferase from newly isolated Bacillus sp. C26
No full textThe kinetic characteristics of β-cyclodextrin production by a
cyclodextrin glycosyltransferase (CGTase) produced by Bacillus sp.
C26, a new isolate from a soil sample was investigated. Considering
highest yield and initial production rate of β-cyclodextrin, among
the starches examined, soluble starch, tapioca starch, sago starch,
corn starch and rice starch, tapioca starch was the best substrate for
this CGTase. The optimum temperature for tapioca starch gelatinization
prior to its use as a substrate for β-cyclodextrin production was
65°C. The yield and initial production rate of β-cyclodextrin
increased with increasing starch concentration up to 6% and an enzyme
concentration up to 48 U/g-starch. The kinetic parameters of Vmax and
Km of β-cyclodextrin production from tapioca starch by CGTase were
1.59 mg/mL/h and 22.3 mg/mL, respectively. Considering high initial
production rate and high yield of β-cyclodextrin, the optimum
reaction temperature was at 50°C. This study provided the
necessary kinetic information that may be useful to define the most
suitable condition for industrialized production of β-cyclodextrin
with the high yield and productivity
Evaluating agro-industrial by-products as dietary roughage source on growth performance of fattening steers
No full textAbstractSilages from pineapple peel, sweet corn husk and cob mixed with bagasse and vinasse were evaluated to determine their chemical composition and fermentation characteristics as well as feeding performance in fattening steers. The experiment, which lasted 90days, involved 48 fattening steers (264±37.4kg BW) randomly allocated to three diets. Treatments included: a control diet containing rice straw and molasses (T1); diet containing bagasse–vinasse mixture including sweet corn husk and cob silage (BS; T2); and diet containing bagasse–vinasse mixture including pineapple peel silage (BP; T3). All treatments included a commercial concentrate feed (13% CP) and ad libitum rice straw throughout the experiment. Results from chemical analysis showed that dry matter (DM) of BS was higher than BP (P<0.05), whereas the protein content of BS and BP was similar (P>0.05). For fermentation characteristics, pH in BP was lower than BS (P<0.05); in addition, acetic and butyric acids in BS were higher than BP (P<0.05). Findings from growth trial showed that total DM intake in steers fed T1 was higher compared to the other dietary treatments (P<0.05), whereas the average BW gain was found to be grater in T3 steers (P<0.05). As result from our findings, bagasse–vinasse mixture with pineapple peel silage appeared to be a viable feed ingredient in fattening steer diet and moreover it could become an economically feasible agro-industrial by-product for farmers
Kinetic characteristics of β-cyclodextrin production by cyclodextrin glycosyltransferase from newly isolated Bacillus sp. C26
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Cyclodextrin glycosyltransferase from a newly isolated alkalophilic <i>Bacillus</i> sp. C26
No full textA cyclodextrin glycosyltransferase (CGTase) producing bacterium was isolated from a farm soil sample and identified as Bacillus sp. C26. The highest CGTase production by Bacillus sp. C26 was achieved using 1% (w/v) sago starch and 1%(w/v) yeast extract as carbon source and nitrogen source, respectively with an initial pH of 10 and a temperature of 37oC. Other carbon sources such as soluble starch and rice starch were almost as good as sago starch but tapioca and corn were poor substrates for CGTase production. There was very little difference between the various N-sources tested i.e. peptone, tryptone and yeast extract. Under the optimal conditions, the specific growth rate and CGTase production rate of Bacillus sp.C26 were 0.193 h-1 and 5.94 U mg-1 h-1, respectively. The partially purified CGTase from Bacillus sp. C26 exhibited 2 peaks of optimum pH at 6.0 and 8.5 and had an optimum temperature of 65oC. The enzyme was stable from pH 7.0 to 9.0 and retained its high activity up to 50oC
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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