Search results for " immobilization"
showing 10 items of 30 documents
Improvement of actinorhodin production yield in Streptomyces coelicolor by immobilized-cell cultivations by using PCL- and PLA-based films
2016
Actinomycetes are Gram-positive bacteria producing most of naturally occurring antibiotics (Donadio et al., 2010). At industrial level, antibiotics are produced by submerged fermentations where the actinomycete filamentous morphology negatively affects bioproductivity (van Dissel et al., 2014). Microporous membranes for bacterial cell-immobilization were already proven increasing bioproductivity in Streptomyces coelicolor, that is a model actinomycete producing the blue pigmented actinorhodin (ACT) antibiotic (Scaffaro et al., 2016). To develop an immobilized-cell bioreactor system, different kinds of polycaprolactone (PCL) and polylactic acid (PLA) films were produced by an electrospinning…
Different Type Clay Amendments for Lead Immobilization in Contaminated Soils
2014
Contamination with lead in soil is a crucial problem in industrial and military sites. Immobilization of lead by natural and modified clay as soil amendment can be an effective solution to this problem. Quaternary and Devonian clays were chosen for modification with NaCl, CaCl2, FeOOH and Ca10(PO4)6(OH)2 in different proportions of Ca/P equimolar ratio to test and compare immobilization efficiency of lead (II) on raw and modified clays by using a batch leaching test. The aim of the study is to compare different types of raw and modified clays as soil amendments by lead immobilization properties.
IMPROVED PRODUCTION OF THE ANTIBIOTIC ACTINORHODIN IN STREPTOMYCES COELICOLOR IMMOBILIZED-MYCELIAL CELL CULTIVATIONS
2017
Objectives i) Evaluation of ACT production in Streptomyces coelicolor M145 mycelial cells immobilized on polycaprolactone (PCL) and polylactic acid (PLA) nanofiber membranes, modified or not by an O2- plasma treatment. ii) Identification of gene products associated with the improvement of ACT production.
Matryoshka enzyme encapsulation: Development of zymoactive hydrogel particles with efficient lactose hydrolysis capability.
2019
This report describes an efficient procedure for enzyme encapsulation and its application for the hydrolysis of lactose. The enzymatic material that has been developed consists of hydrogel particles (ca. 3–4 mm of diameter) composed of either alginate or an alginate-agarose combination, in which bacterial cells loaded with a thermostable β-galactosidase are embedded. The cells were rendered fully permeable to the substrate, either chromogenic p-nitrophenyl galactose or lactose, by thermal treatment at 75 °C. Hydrogel particles made of a mixture of alginate and agarose displayed high catalytic activity (i.e. 1 g of beads hydrolyze the lactose equivalent of 100 mL of milk in 15 min) and therm…
Fluorescenzserologischer Nachweis eines in Syphilitikerseren vorkommenden Antik�rpers gegen ein hitzestabiles Antigen der Reiter-Treponemen
1967
An insgesamt 88 Syphilitikerseren wurde der FTA-Test mit erhitzten Reiter-Treponemen durchgefuhrt. 71 mal reagierte die Serumverdunnung von 1∶100, in 53 Fallen eine solche von 1∶500 positiv. Von 53 Kontrollseren waren nur 2 bei der Verdunnung von 1∶100 positiv. Hieraus wird auf das Vorkommen eines hitzestabilen gemeinsamen Gruppen-Antigens in Reiter-Treponemen und T. pallidum geschlossen. Die Zugehorigkeit dieses Antigens zu den Lipopolysacchariden wird diskutiert. Menschliche Antikorper gegen dieses Antigen sind vorerst nur fluorescenzserologisch nachzuweisen.
Fabrication and characterisation of ZnO nanostructures: from nanoscale building blocks to hybrid nanomaterials - towards emerging technologies in sen…
2012
Metal oxide nanostructures characterized by multiple morphologies and structures are at the forefront of applications driven nanotechnology research. In particular, they represent a versatile solution for performance enhancement and applications in multifunctional devices and offer distinct advantages over their bulk counterparts. The current state in ZnO nanomaterials research and its impact in nanotechnology and modern engineering are discussed through the lens of con-tinuing technological advances in synthetic techniques allowing to obtain the material with predefined specific set of criteria including size, functionality, and uniqueness. Aim of this research activity is fabrication and …
Biomimetic strategy towards gelatin coatings on PET. Effect of protocol on coating stability and cell-interactive properties
2019
Gelatin-modified poly(ethylene terephthalate) (PET) surfaces have been previously realized via an intermediate dopamine coating procedure that resulted in surfaces with superior haemocompatibility compared to unfunctionalized PET. The present study addresses the biocompatibility assessment of these coated PET surfaces. In this context, the stability of the gelatin coating upon exposure to physiological conditions and its cell-interactive properties were investigated. The proposed gelatin–dopamine-PET surfaces showed an increased protein coating stability up to 24 days and promoted the attachment and spreading of both endothelial cells (ECs) and smooth muscle cells (SMCs). In parallel, physi…
Optymalizacja procesu immobilizacji komórek Saccharomyces cerevisiae w żelu alginianowym
2016
Celem prezentowanych badań była ocena wpływu dwuwartościowych kationów wapnia, magnezu i baru, na zdolność sieciowania żelu alginianowego, stosowanego do unieruchamiania komórek Saccharomyces cerevisiae, oraz oznaczenie aktywności enzymatycznej dehydrogenazy bursztynianowej w immobilizowanych komórkach. Do immobilizacji komórek Saccharomyces cerevisiae wykorzystywano zawiesinę komórek drożdży w alginianie sodu, który następnie żelowano roztworami chlorku wapnia (2, 5, 10 i 30%), chlorku baru (1, 2, 3, 4 i 5%) oraz chlorku magnezu (5%). Aktywność dehydrogenazy bursztynianowej badano spektrofotometrycznie i mierzono za pomocą ilości zredukowanego błękitu metylenowego (sztuczny akceptor elektr…
Opracowanie metody oraz optymalizacja warunków immobilizacji inwertazy drożdżowej w żelu alginianowym
2016
Zbadano wpływ różnych stężeń chlorku wapnia oraz czasu kondycjonowania inwertazy drożdżowej (EC 3.2.1.26) izolowanej z drożdży piekarniczych Saccharomyces cerevisiae immobilizowanej w żelu alginianowym. Z wykorzystanych w badaniach różnych stężeń chlorku wapnia (2, 5, 10 i 30%) najwyższą aktywność enzymatyczną uzyskano dla najwyższego wykorzystanego stężenia. Wykazano, że czas 15 minut kondycjonowania żelu alginianowego w chlorku wapnia prowadzi do najefektywniejszego immobilizowania inwertazy. Dodatkowo oceniono wpływ immobilizacji inwertazy drożdżowej na jej aktywność w odniesieniu do wolnej formy tego enzymu w szerokim zakresie pH (3,5; 4,0; 4,5; 5,0; 5,5; 6,0; 6,5) oraz temperatury (21,…
Labile nitrogen, carbon, and phosphorus pools and nitrogen mineralization and immobilization rates at low temperatures in seasonally snow-covered soi…
2006
Surface mineral horizons from four ecosystems sampled in the northwestern Italian Alps were incubated at −3 and +3°C to simulate subnivial and early thaw period temperatures for a seasonally snow-covered area. The soil profiles at these sites represent extreme examples of management, grazed meadow (site M) and extensive grazing beneath larch (site L) or naturally disturbed by avalanche and colonized by alder (site A) and the expected forest climax vegetation beneath fir (site F). Changes in labile pools of nitrogen (N) and phosphorus (P) were active at all sites at both temperatures during 14 days of laboratory incubation. Ammonium was the dominant inorganic form of total dissolved N (TDN),…