oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

4 ( 1 )

2018 ( 9 )

2017 ( 21 )

2016 ( 14 )

Custom range...

Search Results: 1 - 10 of 7319 matches for " Adam;Kordowska-Wiater "
All listed articles are free for downloading (OA Articles)
Page 1 /7319
Display every page Item
Application of response surface methodology to enhancement of biomass production by Lactobacillus rhamnosus E/N
Polak-Berecka, Magdalena;Wa?ko, Adam;Kordowska-Wiater, Monika;Targoński, Zdzis?aw;Kubik-Komar, Agnieszka;
Brazilian Journal of Microbiology , 2011, DOI: 10.1590/S1517-83822011000400035
Abstract: response surface methodology (rsm) was employed to study the effects of various medium components on biomass production by lactobacillus rhamnosus e/n. this strain is commonly used in the pharmaceutical and food industries due to its beneficial effect on the human gut and general health. the best medium composition derived from rsm regression was (in g/l) glucose 15.44, sodium pyruvate 3.92, meat extract 8.0, potassium phosphate 1.88, sodium acetate 4.7, and ammonium citrate 1.88. with this medium composition biomass production was 23 g/l of dry cell weight after 18 h of cultivation in bioreactor conditions, whereas on mrs the yield of biomass was 21 g/l of dry cell weight. the cost of 1 g of biomass obtained on mrs broth was calculated at the level of 0.44 € whereas on the new optimal medium it was 25% lower. it may be concluded then, that the new medium, being cheaper than the control mrs allows large scale commercial cultivation of the l. rhamnosus strain. this study is of relevance to food industry because the possibility to obtain high yield of bacterial biomass is necessary step in manufacturing of probiotic food.
The influence of selected prebiotics on the growth of lactic acid bacteria for bio-yoghurt production
Waldemar Gustaw,Monika Kordowska-Wiater,Justyna Kozio?
Acta Scientiarum Polonorum : Technologia Alimentaria , 2011,
Abstract: Background. Prebiotics are a category of nutritional com-pounds grouped together, not necessarily by structural similarities, but by ability to promote the growth of spe-cific beneficial (probiotic) gut bacteria. Fructooligosaccharides (FOS) and inulin are among the most famous prebiotic compounds. In order to improve viability of probiotic bacteria during storage, fermented food should be supplemented with prebiotics. Material and methods. Yoghurts were produced from skimmed milk powder and prebiotics (FOS, inulin or resistant starch), which were added at concentrations of 1%, 2% and 3%. Yoghurts were stored in +4°C for three weeks. Every week each kind of fermented drink was examined in order to check the growth of lactic acid bacteria. Apparent viscosity and texture of bio-yoghurt were determinated during refrigerated storage. Results. The FOS and inulin addition to yoghurt caused an increase in the numbers of all bacteria in comparison to control yoghurt obtained without addition of prebiotics. The viable counts of Str. thermophilus, Lb. acidophilus and Bifidobacterium sp. when 1% of FOS was added to yoghurt were about 9 log cfu/g, 7.8 log cfu/g and 7.7 log cfu/g, respectively. In the presence of 1% of inulin, streptococci and bifidobacteria reached the growth at the level 8.8 log cfu/g and 7.5 respectively. Hardness and adhesiveness of yoghurt obtained with addition resistant starch increased systematically during 21 days of refrigerated storage. Conclusions. The numbers of lactic acid bacteria in obtained bio-yoghurts were sufficient in 97% of samples (106-109 cfu/g) according to FAO/WHO protocols. Generally, viability of bacteria was sufficient for 14 days and then their numbers decreased but usually not below 106 cfu/g. Prebiotics as FOS and inulin added to bio-yoghurt exhibited stimulatory effect on growth Lb. acidophilus and Bifidobacterium sp. Addition of prebiotics caused an increase in apparent viscosity and hardness (in case of FOS) and decrease in syneresis of obtained bio-yoghurts.
The immunohistochemical demonstration of parafollicular cells and evaluation of calcium-phosphate balance in patients with thyroid hemiagenesis
Marek Ruchala,Ewelina Szczepanek,Patrycja Sujka-Kordowska,Maciej Zabel
Folia Histochemica et Cytobiologica , 2011, DOI: 10.5603/4128
Abstract: Thyroid hemiagenesis (TH) is characterized by the congenital absence of one thyroid lobe. The aim of this study was to evaluate the calcium-phosphate balance in TH. Twenty patients with TH and 20 controls with a bilobed thyroid were studied. Serum concentrations of total calcium, parathormon and calcitonin were measured. Additionally, the immunohistochemical expression of calcitonin, chromogranin A (chA), neuron-specific enolase (NSE) and calcitonin gene-related peptide (CGRP) was evaluated in surgical specimens from patients with TH and controls. There were no significant differences in biochemical parameters between TH and controls. Positive staining for calcitonin was demonstrated in 3/8 thyroid sections from three patients with TH, but only in 2/33 sections from four controls (p < 0.005). All sections from patients with TH positive for calcitonin also expressed chA, NSE and CGRP. Two sections from controls positive for calcitonin presented an additionally positive reaction for chA, and one of them also for NSE. None presented positive staining for CGRP. Of three TH sections, in one, hyperplasia of C cells of medium grade, and in another hyperplasia of C cells of high grade, could be detected. In the controls, hyperplasia of C cells of low and medium grade was observed. TH was associated with slightly enhanced C cells hyperplasia compared to controls, which might indicate compensatory proliferation. However, the calcium-phosphate balance does not seem to be significantly affected. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 2, pp. 299–305)
Comparative Studies on the Induction of Trichoderma harzianum Mutanase by α-(1→3)-Glucan-Rich Fruiting Bodies and Mycelia of Laetiporus sulphureus
Adrian Wiater,Ma?gorzata Pleszczyńska,Janusz Szczodrak,Grzegorz Janusz
International Journal of Molecular Sciences , 2012, DOI: 10.3390/ijms13089584
Abstract: Mutanase (α-(1→3)-glucanase) is a little-known inductive enzyme that is potentially useful in dentistry. Here, it was shown that the cell wall preparation (CWP) obtained from the fruiting body or vegetative mycelium of polypore fungus Laetiporus sulphureus is rich in α-(1→3)-glucan and can be successfully used for mutanase induction in Trichoderma harzianum. The content of this biopolymer in the CWP depended on the age of fruiting bodies and increased along with their maturation. In the case of CWP prepared from vegetative mycelia, the amount of α-(1→3)-glucan depended on the mycelium age and also on the kind of medium used for its cultivation. All CWPs prepared from the individually harvested fruiting body specimens induced high mutanase activity (0.53–0.82 U/mL) in T. harzianum after 3 days of cultivation. As for the CWPs obtained from the hyphal mycelia of L. sulpureus, the maximal enzyme productivity (0.34 U/mL after 3 days of incubation) was recorded for CWP prepared from the 3 week-old mycelium cultivated in Sabouraud medium. Statistically, a high positive correlation was found between the total percentage content of α-(1→3)-glucan in the CWP and the mutanase activity.
Variation in Total Polyphenolics Contents of Aerial Parts of Potentilla Species and Their Anticariogenic Activity
Micha? Tomczyk,Ma?gorzata Pleszczyńska,Adrian Wiater
Molecules , 2010, DOI: 10.3390/molecules15074639
Abstract: The aerial parts of selected Potentilla species (P. anserina, P. argentea, P. erecta, P. fruticosa, P. grandiflora, P. nepalensis, P. norvegica, P. pensylvanica, P. crantzii and P. thuringiaca) were investigated in order to determine their contents of polyphenolic compounds. The results showed that P. fruticosa has relatively high concentrations of tannins (167.3 ± 2.0 mg/g dw), proanthocyanidins (4.6 ± 0.2 mg/g dw) and phenolic acids (16.4 ± 0.8 mg/g dw), as well as flavonoids (7.0 ± 1.1 mg/g dw), calculated as quercetin. Furthermore, we investigated the in vitro inhibitory effects of aqueous extracts from these species against cariogenic Streptococcus spp. strains. It was found that the tested samples moderately inhibit the growth of oral streptococci. However, all the preparations exhibited inhibitory effects on water-insoluble α-(1→3)-, α-(1→6)-linked glucan (mutan) and artificial dental plaque formation. The extract from P. fruticosa showed the highest anti-biofilm activities, with minimum mutan and biofilm inhibition concentrations of 6.25–25 and 50–100 μg/mL, respectively. The results indicate that the studied Potentilla species could be a potential plant material for extracting biologically active compounds, and could become a useful supplement for pharmaceutical products as a new anticariogenic agent in a wide range of oral care products.
Production and use of mutanase from Trichoderma harzianum for effective degradation of streptococcal mutans
Wiater, Adrian;Szczodrak, Janusz;Pleszczynska, Malgorzata;Próchniak, Katarzyna;
Brazilian Journal of Microbiology , 2005, DOI: 10.1590/S1517-83822005000200008
Abstract: basic cultural parameters affecting mutanase production by trichoderma harzianum f-340 in shaken flasks and aerated fermenter cultures have been standardized. the best medium for enzyme production was mandels medium a with initial ph 5.3, supplemented with 0.3% mutan and 0.05% peptone and inoculated with 20% of the 72-h mycelium as inoculum. it was shown that mycelial mass, used in the culture medium as a sole carbon source, induced mutanase synthesis and could be utilized as an inexpensive and easily available substitute for bacterial mutan. application of optimized medium and cultural conditions enabled us to obtain a high mutanase yield (0.6-0.7 u/ml, 2.0-2.5 u/mg protein) in a short period of time (3-5 days), which was much higher than the best reported in literature. the enzyme in crude state was stable in the ph range of 4.5-6.0, and at temperatures of up to 40oc; its maximum activity was recorded at 45oc and at ph 5.5. the mutanase preparation obtained from the t. harzianum fungus was relatively stable under storage conditions, and showed a high hydrolytic potential in reaction with a mixed-linkage (a-1,3, a-1,6) water-insoluble mutan of streptococcal origin (hydrolysis yield reached a value of 69% in 24 h). steady-state measurement of the enzymic reaction products during the hydrolysis revealed that mutanase exhibited an exo type of action on mutan. thin-layer chromatographic analysis showed that glucose was the primary final product of mutan hydrolysis with mutanase. the potential application of mutanase in dentistry is discussed.
In Vitro Anticariogenic Effects of Drymocallis rupestris Extracts and Their Quality Evaluation by HPLC-DAD-MS3 Analysis
Micha? Tomczyk,Ma?gorzata Pleszczyńska,Adrian Wiater,Sebastian Granica
Molecules , 2013, DOI: 10.3390/molecules18089117
Abstract: In this study, for the first time, we investigated in vitro inhibitory effects of Drymocallis rupestris extracts and their subfractions obtained with solvents of different polarity (aqueous, 50% ethanolic, diethyl ether, ethyl acetate and n-butanolic) against bacterial viability and caries virulence factors of Streptococcus spp. strains. The diethyl ether subfraction (PRU2) showed bacteriostatic and bactericidal activity against mutans streptococci, with minimum inhibitory concentrations (MICs) in the range of 0.75–1.5 mg/mL and minimum bactericidal concentrations (MBCs) in the range of 1.5–3 mg/mL. Furthermore, PRU2 inhibited biofilm formation by Streptococci in a dose-dependent manner. It was also found that all five D. rupestris preparations exhibited diverse inhibitory effects on de novo synthesis of water-insoluble and water-soluble α-d-glucans by glucosyltransferases of the mutans group streptococci. The phytochemical profile of investigated samples was determined by spectrophotometric and chromatographic (HPLC-DAD-MS 3) methods. The high polyphenol (total phenol, phenolic acids, tannins, proantocyanidins, and flavonoids) contents were found which correlated with anticariogenic activity of the analyzed samples. The results demonstrate that D. rupestris extracts and their subfractions could become useful supplements for pharmaceutical products as a new anticariogenic agent in a wide range of oral care products. Further studies are necessary to clarify which phytoconstituents of D. rupestris are responsible for anticaries properties.
Information Systems Development Methodolgies in Developing Higher Education  [PDF]
Adam Marks
Creative Education (CE) , 2012, DOI: 10.4236/ce.2012.31019
Abstract: Studies concerned with the status of Information Systems Development Methodologies usage in many developing countries including the factors that influence and motivate their use, current trends, difficulties, and barriers to adoption are lacking, especially within the higher education sector. This paper examines these identified gaps in a developing country, namely the United Arab Emirates. The initial findings reveal that there is limited knowledge and understanding of the concept of ISDM in federal higher education institutions in the UAE. This is reflected in the quality of the software products being developed and released. However, the analysed data also reveals a trend whereby federal higher education institutions in the UAE are gradually moving towards increased ISDM adoption and deployment.
Introducing Liability Dollarization and Contractionary Depreciations to the IS Curve  [PDF]
Adam Honig
Modern Economy (ME) , 2012, DOI: 10.4236/me.2012.34061
Abstract: This paper presents a simple modification to the standard IS curve used, at least implicitly, by policymakers that allows capital flight to have a contractionary effect in emerging market economies. In the standard model, capital flight leads to an expansionary shift in the IS curve through an increase in net exports. However, in the presence of liability dollarization for domestic firms, a currency depreciation triggered by capital flight leads to an investment collapse. A simple adjustment to the standard investment schedule captures this channel and allows for the possibility that capital flight yields a contractionary shift in the IS curve.
Which Working Memory Components Predict Fluid Intelligence: The Roles of Attention Control and Active Buffer Capacity  [PDF]
Adam Chuderski
Psychology (PSYCH) , 2014, DOI: 10.4236/psych.2014.55043
Abstract:

This study tested which of two crucial mechanisms of working memory (WM): attention control, consisting of focusing attention on the proper task-set as well as blocking distraction, and the active buffer capacity, related to the number of chunks that can be actively maintained, plays a more important role in WM’s contribution to fluid intelligence. In the first study, the antisaccade task was used, the standard measure of attention control, in a modified variant which resulted in scores less sensitive to individual differences in the active buffer capacity, in comparison to the standard variant. In effect, attention control became a weak predictor of Gf, explaining less than one third of its variance accounted for by the capacity. In the second study, a variant of another attention control test, the Stroop task, was applied, which minimized the load on capacity, and no significant contribution of this task to Gf was found. Thus, when contribution of control and capacity were unconfounded, attention control mechanisms of WM contributed to fluid intelligence to a lesser extent than did the mechanisms related to the active buffer of WM.

Page 1 /7319
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.