17 research outputs found

    The production of wax esters in transgenic plants: towards a sustainable source of bio-lubricants.

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    Wax esters are high-value compounds used as feedstocks for the production of lubricants, pharmaceuticals, and cosmetics. Currently, they are produced mostly from fossil reserves using chemical synthesis, but this cannot meet increasing demand and has a negative environmental impact. Natural wax esters are also obtained from Simmondsia chinensis (jojoba) but comparably in very low amounts and expensively. Therefore, metabolic engineering of plants, especially of the seed storage lipid metabolism of oil crops, represents an attractive strategy for renewable, sustainable, and environmentally friendly production of wax esters tailored to industrial applications. Utilization of wax ester-synthesizing enzymes with defined specificities and modulation of the acyl-CoA pools by various genetic engineering approaches can lead to obtaining wax esters with desired compositions and properties. However, obtaining high amounts of wax esters is still challenging due to their negative impact on seed germination and yield. In this review, we describe recent progress in establishing non-food-plant platforms for wax ester production and discuss their advantages and limitations as well as future prospects

    Technologiczne wsparcie komunikacji pośredników nieruchomości – ocena zjawiska

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    Globalization and the development of modern information technology have contributed to the higher importance of communication technological support and its use between the client and the entrepreneur in the service industry. Such tendencies also apply to real estate companies, in particular to real estate agents and brokers. The purpose of this article is to identify the level of service adaptation of the real estate brokerage industry to the general tendencies characterizing the service sector. Two research questions were proposed in the article. The first one is about adjustment of the communication tools used by the real estate brokerage industry to the trends in the services market. The second one includes the assessment of the tools’ efficiency in the opinion of the estate brokers and agents. The literature and critical analysis as well as an introductory survey of real estate agents and brokers were all used in this paper. The introductory survey was conducted with the use of webform among real estate agents affiliated to Powszechne Towarzystwo Ekspertów i Doradców Rynku Nieruchomości, between the 2nd of October and 15th of November 2017. After a basic analysis, we can conclude that the real estate sector is quite similar to other services’ sectors as far as the new means of communication usage in contacts with clients are concerned. The empirical studies results show that tools such as smartphone and laptop in combination with social media play an important role in today’s communication trends. The role of traditional means of communication, on the other hand, such as leaflets and newspapers has significantly decreased.W dobie globalizacji i rozwoju nowoczesnych technologii informatycznych coraz większą rolę odgrywa wsparcie technologiczne środków komunikacji w kontaktach między klientem a przedsiębiorcą w branży usługowej. Takie tendencje dotyczą również przedsiębiorstw związanych z obsługą rynku nieruchomości, a w szczególności z pośrednictwem w obrocie nieruchomościami. Celem artykułu jest identyfikacja poziomu dostosowania usług w branży pośrednictwa nieruchomości do ogólnych tendencji charakteryzujących sektor usług. W artykule zostały postawione dwa pytania badawcze. Pierwsze dotyczy dostosowania poziomu wykorzystywania narzędzi wspomagających komunikację w branży pośrednictwa nieruchomości na rynku usług, a drugie oceny skuteczności wykorzystywanych narzędzi w opinii pośredników. Dla potrzeb opracowania przeprowadzono analizę literatury, analizę krytyczną oraz pilotażowe badania ankietowe wśród pośredników obrotu nieruchomościami

    Detailed characterization of the substrate specificity of mouse wax synthase

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    Wax synthases are membrane-associated enzymes catalysing the esterification reaction between fatty acyl-CoA and a long chain fatty alcohol. In living organisms, wax esters function as storage materials or provide protection against harmful environmental influences. In industry, they are used as ingredients for the production of lubricants, pharmaceuticals, and cosmetics. Currently the biological sources of wax esters are limited to jojoba oil. In order to establish a large-scale production of desired wax esters in transgenic high-yielding oilseed plants, enzymes involved in wax esters synthesis from different biological resources should be characterized in detail taking into consideration their substrate specificity. Therefore, this study aims at determining the substrate specificity of one of such enzymes -; the mouse wax synthase. The gene encoding this enzyme was expressed heterologously in Saccharomyces cerevisiae. In the in vitro assays (using microsomal fraction from transgenic yeast), we evaluated the preferences of mouse wax synthase towards a set of combinations of 11 acyl-CoAs with 17 fatty alcohols. The highest activity was observed for 14:0-CoA, 12:0-CoA, and 16:0-CoA in combination with medium chain alcohols (up to 5.2, 3.4, and 3.3 nmol wax esters/min/mg microsomal protein, respectively). Unsaturated alcohols longer than 18°C were better utilized by the enzyme in comparison to the saturated ones. Combinations of all tested alcohols with 20:0-CoA, 22:1-CoA, or Ric-CoA were poorly utilized by the enzyme, and conjugated acyl-CoAs were not utilized at all. Apart from the wax synthase activity, mouse wax synthase also exhibited a very low acyl-CoA:diacylglycerol acyltransferase activity. However, it displayed neither acyl-CoA:monoacylglycerol acyltransferase, nor acyl-CoA:sterol acyltransferase activity

    Lipid metabolism and accumulation in oilseed crops

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    Triacylglycerols (TAGs) serve as the most important storage form of energy and carbon in eukaryotic cells and thus are one of the fundamental macronutrients for animal and human diet. They are also used as a major feedstock for diverse industrial and energetic sectors due to their high energy density. Oilseed crops represent the most valuable source of TAGs and major world sources of edible oils. Originally, oilseeds of various species were used as a model to decipher plant lipid synthesis pathways. Given the continuous progress in research on plant lipid metabolism, here we provide an overview and update on the current state of knowledge related mainly to storage lipids in oilseeds. Moreover, we present the latest evidences on the molecular networks governing metabolism not only of TAGs but also of other seed lipids, like wax esters, sterols and sphingolipids. Finally, this review also provides a framework for understanding the complex lipid web existing in oilseeds

    Les clusters de gènes codant pour les vésicules gazeuses dans les cyanobactéries du genre Arthrospira (Oscillatoriales, Cyanophyta) et leur correlation avec la phylogénie basée sur l' ITS

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    The genus Arthrospira comprises filamentous cyanobacteria in which the trichomes form an open helix and contain gas vacuoles. The gas vesicle gene cluster of five Arthrospira strains was amplified by PCR and sequenced. The genes are organized in one operon, in the order gvpA1–gvpC1–gvpA2–gvpC2–gvpA3–gvpC3–gvpN. In Arthrospira sp. strain PCC 8005, the genes gvpJ, gvpK, gvpV and gvpW were also identified. Each of the three copies of gvpA encodes a protein of 71 amino acids. In the case of gvpC, there are two different length variants. Each of the two shorter genes, gvpC1 and gvpC2, encodes a putative protein of 151 amino acids, while the longer one, gvpC3, codes for a putative protein of 284 residues. The amino acid sequences of GvpC1 and GvpC2 are identical to the N-terminal part of GvpC3. In spite of the presence of stop codons downstream of gvpC1 and gvpC2, the deduced amino acid sequences in these regions are highly similar to the C-terminal part of GvpC3 (residues 160 to 229). The GvpC1, GvpC2 and GvpC3 proteins contain contiguous repeats of 33 amino acids as previously reported for other cyanobacteria. The sequences of the gvpA1, gvpC1, gvpA2 and gvpC2 genes were not found in the genome data of Arthrospira sp. PCC 8005, A. maxima CS-328, and A. platensis NIES-39 as a result of incomplete assembly. The genes gvpN and gvpJ located downstream of gvpC3, encode putative proteins of 394 and 127 amino acids, respectively. The deduced amino acid sequences of gvpK, gvpV and gvpW contain 151, 112 and 227 residues, respectively. The analysis of gvp sequences of five strains of Arthrospira revealed the presence of polymorphic positions, which distinguished the strains in agreement with their previous assignments to ITS clusters I and II. This is the first report of gvp genes in members of the genus Arthrospira.The Arthrospira genus: case model for the improvement of cyanobacterial taxonomy on the basis of Multi-Locus Sequence Typing (MLST

    Powikłania internistyczne pediatrycznego przypadku ziarniniakowatości z zapaleniem naczyń

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    Ziarniniakowatość z zapaleniem naczyń (GPA) jest ANCA-zależnym zapaleniem małych naczyń (AAV, ANCA associated vasculitides) rzadko występującym w populacji dziecięcej. Zmiany dotyczą małych naczyń i lokalizują się przede wszystkim w górnych i dolnych drogach oddechowych oraz w nerkach. W pracy przedstawiono opis przypadku GPA u 15-letniego chłopca z ciężkim przebiegiem choroby oraz opisano odległe powikłania zastosowanego leczenia. Podejście do leczenia AAV w okresie ostatnich kilku lat uległo znaczącej zmianie dzięki nowym lekom oraz randomizowanym badaniom klinicznym

    IgA vasculitis nephritis clinical course and kidney biopsy : national study in children

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    Abstract The aim of the study was to investigate the relationship between the severity of typical clinical symptoms, severity of histopathological lesions in kidney biopsies in IgA vasculitis nephritis (IgAVN) and to propose indications for kidney biopsy in children. Material and methods This retrospective study enrolled 106 patients, included in the IgAVN registry of Polish children, diagnosed by kidney biopsy. Renal and extrarenal symptoms at onset of the disease were analyzed. Biopsy results were assessed using Oxford classifications (MEST-C). The patients were divided into 3 groups depending on the severity of proteinuria: A-nephrotic proteinuria with hematuria; B-non-nephrotic proteinuria with hematuria; C-isolated hematuria. Results The first symptoms of nephropathy were observed at the 0.7 (1–128.4) months from the onset of extrarenal symptoms. Kidney biopsy was performed on 39 (6–782) days after the onset of nephropathy symptoms. MEST-C score 4 or 5 was significantly more frequent in children from group A than in groups B and C. Significantly higher mean MEST-C score was found in patients with abdominal symptoms than without. In group A: S0 and T0 we found in significantly shorter time to kidney biopsy than in S1, T1–2 p < 0.05) and in group B the significantly shorter time in T0 compare to T1–2 p < 0.05). The ROC analysis shows that S1 changes appear in kidney biopsies in group A with cut off 21 days (AUC 0,702, p = 0.004, sensitivity 0.895 specificity 0.444) T1–2 changes after 35 days (AUC 0.685, p = 0.022, sensitivity 0.750, specificity 0.615), and in goupn B T1–2 cut off is 74 days (AUC 0,738, p = 0.002, sensitivity 0.667, specificity 0.833). Conclusions In childhood IgAVN, the severity of changes in the urine is clearly reflected in the result of a kidney biopsy. The biopsy should be performed in patients with nephrotic proteinuria no later than 3 weeks after the onset of this symptom in order to promptly apply appropriate treatment and prevent disease progression. Accompanying abdominal symptoms predispose to higher MESTC score

    The role of complement component C3 activation in the clinical presentation and prognosis of IgA nephropathy - a national study in children

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    The aim of the study was to evaluate the influence of the intensity of mesangial C3 deposits in kidney biopsy and the serum C3 level on the clinical course and outcomes of IgAN in children. The study included 148 children from the Polish Pediatric IgAN Registry, diagnosed based on kidney biopsy. Proteinuria, creatinine, IgA, C3 were evaluated twice in the study group, at baseline and the end of follow-up. Kidney biopsy was categorized using the Oxford classification, with a calculation of the MEST-C score. The intensity of IgA and C3 deposits were rated from 0 to +4 in immunofluorescence microscopy. The intensity of mesangial C3 > +1 deposits in kidney biopsy has an effect on renal survival with normal GFR in children with IgAN. A reduced serum C3 level has not been a prognostic factor in children but perhaps this finding should be confirmed in a larger group of children
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