Time filter

Source Type

Poznan, Poland

The University of Life science in Poznań is a higher-education institution in Poznań, Poland. It officially gained university status on 11 April 2008. Its previous name was Akademia Rolnicza im. Augusta Cieszkowskiego w Poznaniu, literally "August Cieszkowski Agricultural Academy in Poznań", although it styled itself in English as "The August Cieszkowski Agricultural University of Poznań".The institution was established in 1951 from Agriculture and Forestry faculties which had existed since 1919 at Adam Mickiewicz University.The university has faculties of Agronomy, Forestry, Animal Breeding and Biology, Wood Technology, Horticulture, Food Science and Nutrition, Land Reclamation and Environmental Engineering, and Economics and Social science. Wikipedia.

Szymanowska-Powalowska D.,University of Life Sciences in Poznan
Electronic Journal of Biotechnology | Year: 2014

Background: The production of biofuels from renewable energy sources is one of the most important issues in industrial biotechnology today. The process is known to generate various by-products, for example crude glycerol, which is obtained in the making of biodiesel from rapeseed oil. Crude glycerol may be utilized in many ways, including microbial conversion to 1,3-propanediol (1,3-PD), a raw material for the synthesis of polyesters and polyurethanes.Results: The paper presents results of a study on the synthesis of 1,3-propanediol from crude glycerol by a repeated batch method with the use of Clostridium butyricum DSP1. Three cycles of fermentation medium replacement were carried out. The final concentration of 1,3-PD was 62 g/L and the maximum productivity, obtained during the second cycle, reached 1.68 g/L/h. Additionally, experiments conducted in parallel to the above involved using the entire quantity of the culture broth removed from the bioreactor to inoculate successive portions of fermentation media containing crude glycerol at concentrations of 80 g/L and 100 g/L. Under those conditions, the maximum 1,3-PD concentrations were 43.2 g/L and 54.2 g/L.Conclusions: The experiments proved that by using a portion of metabolically active biomass as inoculum for another fermentation formula it is possible to eliminate the stage of inoculum growth and thereby reduce the length of the whole operation. Additionally, that strategy avoids the phase of microbial adaptation to a different source of carbon such as crude glycerol, which is more difficult to utilize, thus improving the kinetic parameters of 1,3-PD production. © 2014 Pontificia Universidad Católica de Valparaíso. Production and hosting by Elsevier B.V. All rights reserved.

Chmurzynska A.,University of Life Sciences in Poznan
Nutrition Reviews | Year: 2010

Complex traits, including those involved in diet-related diseases, are determined by multiple genes and environmental influences. Factors influencing the development of complex traits should be expanded to include epigenetic factors, such as DNA methylation, which occurs in utero. Epigenetic factors regulate gene expression and thereby cell differentiation and organogenesis. The process of epigenotype establishment is sensitive to environmental conditions, with nutrition being one of the most important related factors. For example, DNA methylation depends on the availability of several nutrients including methionine and vitamins B6, B12, and folate. Epidemiological studies show that undernutrition during fetal life is associated with increased susceptibility to complex diseases. Numerous studies have been conducted on prenatal caloric and protein undernutrition. A reduction in the number of cells and changes in the structure and functioning of organs, as well as permanent changes in DNA methylation and gene expression, have been considered the molecular mechanisms responsible for metabolism programming. © 2010 International Life Sciences Institute.

Cieslak A.,University of Life Sciences in Poznan
Animal : an international journal of animal bioscience | Year: 2013

A wide range of plant bioactive components (phytochemicals) have been identified as having potential to modulate the processes of fermentation in the rumen. The use of plants or plant extracts as natural feed additives has become a subject of interest not only among nutritionists but also other scientists. Although a large number of phytochemicals (e.g. saponins, tannins and essential oils) have recently been investigated for their methane reduction potential, there have not yet been major breakthroughs that could be applied in practice. A key tenet of this paper is the need for studies on the influence of plant components on methane production to be performed with standardized samples. Where there are consistent effects, the literature suggests that saponins mitigate methanogenesis mainly by reducing the number of protozoa, condensed tannins both by reducing the number of protozoa and by a direct toxic effect on methanogens, whereas essential oils act mostly by a direct toxic effect on methanogens. However, because the rumen is a complex ecosystem, analysis of the influence of plant components on the populations of methanogens should take into account not only the total population of methanogens but also individual orders or species. Although a number of plants and plant extracts have shown potential in studies in vitro, these effects must be confirmed in vivo.

Blazejewski R.,University of Life Sciences in Poznan
International Journal of Multiphase Flow | Year: 2012

Applicability of the pseudo-fluid concept in the case of settling monosized rigid spheres in the viscous regime was partially confirmed using theoretical elaborations and empirical data on viscosity of suspensions. Three formulae: by Richardson and Zaki, Hawksley as well as Eq. (28), giving almost identical results for volumetric concentrations φ<0.55, have overestimated the settling velocities of suspensions comparing with available experimental results and predictions by the rest of analyzed formulae. The most probable reason for this discrepancy is omission of collisions between more than two relatively large (non-Brownian) particles in terms describing the apparent viscosity of the denser suspensions, which behave as non-Newtonian fluids. That discrepancy can be reduced by a replacement of the mean backflow velocity w f with the maximum one w fm=2w f in the formula for slip velocity, which reduces the relative settling velocity by a factor (1+φ) -1.For suspensions with concentration φ<0.2 the factor (1+φ) -1 is equivalent numerically to the voidage (1 - φ). © 2011 Elsevier Ltd.

Celinska E.,University of Life Sciences in Poznan
Biotechnology Advances | Year: 2010

The history of 1,3-propanediol (1,3-PD) conversion from being a specialty chemical to being a bulk chemical illustrates that the concerted effort of different metabolic engineering approaches brings the most successful results. In order to metabolically tailor the 1,3-PD production pathway multiple strategies have been pursued. Knocking-out genes responsible for by-products formation, intergeneric transfer and overexpression of the genes directly involved in the pathway, manipulation with internal redox balance, introduction of a synthetic flux control point, and modification of the substrate mechanism of transport are some of the strategies applied. The metabolic engineering of the microbial 1,3-PD production exploits both native producers and microorganisms with acquired ability to produce the diol via genetic manipulations. Combination of the appropriate genes from homologous and heterologous hosts is expected to bring a desired objective of production of 1,3-PD cheaply, efficiently and independently from non-renewable resources. The state-of-the-art of the 1,3-PD pathway metabolic engineering is reviewed in this paper. © 2010 Elsevier Inc.

Discover hidden collaborations