OBJECTIVES: To improve the storage stability and reusability of various yeast strains and species by immobilization in polyvinyl alcohol (PVA) hydrogel particles. RESULTS: Debaryomyces hansenii, Pichia sorbitophila, Saccharomyces cerevisiae, Yarrowia lipolytica, and Zygosaccharomyces rouxii were immobilized in PVA particles using LentiKats technology and stored in sterile water at 4 °C. The immobilization improved the survival of all species; however, the highest storage stability was achieved for S. cerevisiae and Y. lipolytica which survived more than 1 year, in contrast to free cells that survived for only 3 months. Tests of the reusability of immobilized recombinant laccase-secreting S. cerevisiae revealed that the cells were suitable for repetitive use (55 cycles during 15 months) even after storage in water at 4 °C for 9 months. A suitable method for killing immobilized laccase-secreting cells without affecting the produced enzyme activity was also developed. CONCLUSIONS: The immobilization of yeasts in PVA hydrogel enables long-term, cheap storage with very good cell viability and productivity, thus becoming a promising approach for industrial applications.
- MeSH
- biotechnologie MeSH
- buněčné kultury MeSH
- imobilizované buňky * cytologie enzymologie metabolismus MeSH
- lakasa chemie metabolismus MeSH
- mikrobiální viabilita MeSH
- ochrana biologická metody MeSH
- opakované použití vybavení MeSH
- polyvinylalkohol chemie MeSH
- rekombinantní proteiny chemie metabolismus MeSH
- Saccharomyces cerevisiae * cytologie enzymologie metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
The use of autologous fat grafting in breast reconstruction still requires optimization. Fat survival and calcification are the main issues that affect the outcomes of the procedure. In this study, a cell-based therapy utilizing laminin-alginate beads (LABs) as carriers was proposed to promote cell survival and adipogenesis by providing short-term physical support and facilitate nutrient diffusion of the implants. Laminin-modified alginate beads were fabricated by immobilizing laminin onto ring-opened alginate, used to encapsulate 3T3-L1 preadipocytes, and evaluated in vitro and in vivo. LABs as preadipocyte carriers showed better biocompatibility and stability than unmodified alginate beads. Preadipocytes in LABs had higher survival rate and enhanced adipogenesis than those in unmodified alginate beads. In vivo studies showed that LABs gradually degraded and the sites were replaced by newly formed fat tissues, and new blood vessels were also observed. 7T-MRI study mimicking clinical fat grafting showed that LABs carrying adipose stem cells improved the results of conventional fat grafts. Therefore, we believe that LABs represent promising cell carriers and can be potentially used for the reconstruction of breasts or other soft tissues in the future.
- MeSH
- adipogeneze * MeSH
- algináty chemie MeSH
- buňky 3T3-L1 MeSH
- imobilizované buňky * metabolismus transplantace MeSH
- kyselina glukuronová chemie MeSH
- kyseliny hexuronové chemie MeSH
- laminin chemie MeSH
- myši inbrední NOD MeSH
- myši SCID MeSH
- myši MeSH
- potkani Sprague-Dawley MeSH
- tukové buňky * metabolismus transplantace MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
White rot fungi (WRF) are applicable to biodegradation of recalcitrant pollutants. However, excessive biomass growth typical for WRF cultivation can hinder their large scale applications. Therefore, immobilization of Irpex lacteus to liquid-core alginate beads restricting excessive mycelium growth and simultaneously keeping high degradation rate of pollutants was tested. Effective diffusivities of dyes to the beads varied from (2.98 ± 0.69) × 10(-10) to (10.27 ± 2.60) × 10(-10) m(2)/s. Remazol Brilliant Blue R (RBBR), Reactive Orange 16 (RO16), and Naphthol Blue Black (NBB) were used as model dyes. The immobilized fungus decolorized model dyes when applied both in microwell plates and in fluidized bed reactors. Using the microwell plates, the apparent reaction rate constants ranged from (2.06 ± 0.11) × 10(-2) to (11.06 ± 0.27) × 10(-2) 1/h, depending on the dye used and its initial concentration. High initial concentrations negatively affected the dye decolorization rate. No fungal growth outside the beads was observed in fluidized bed reactors and thus no operational problems linked to an excessive biomass growth occurred. When RBBR was decolorized in subsequent batches in the fluidized bed reactor, the apparent reaction rate constant increased from (11.63 ± 0.35) × 10(-2) to (29.26 ± 7.19) × 10(-2) 1/h.
- MeSH
- algináty chemie MeSH
- barvicí látky metabolismus MeSH
- biodegradace MeSH
- chemické látky znečišťující vodu metabolismus MeSH
- imobilizované buňky chemie metabolismus MeSH
- kyselina glukuronová chemie MeSH
- kyseliny hexuronové chemie MeSH
- mycelium chemie růst a vývoj metabolismus MeSH
- Polyporales chemie růst a vývoj metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
A simple procedure for the synthesis of magnetic fluid (ferrofluid) stabilized by poly(methacrylic acid) has been developed. This ferrofluid was used to prepare a novel type of magnetically responsive chitosan-based composite material. Both ferrofluid and magnetic chitosan composite were characterized by a combination of microscopy (optical microscopy, TEM, SEM), scattering (static and dynamic light scattering, SANS) and spectroscopy (FTIR) techniques. Magnetic chitosan was found to be a perspective material for various bioapplications, especially as a magnetic carrier for immobilization of enzymes and cells. Lipase from Candida rugosa was covalently attached after cross-linking and activation of chitosan using glutaraldehyde. Baker's yeast cells (Saccharomyces cerevisiae) were incorporated into the chitosan composite during its preparation; both biocatalysts were active after reaction with appropriate substrates.
- MeSH
- Candida enzymologie MeSH
- chitosan chemie MeSH
- enzymy imobilizované chemie MeSH
- fungální proteiny chemie MeSH
- imobilizované buňky cytologie metabolismus MeSH
- kyseliny polymethakrylové chemie MeSH
- lipasa chemie MeSH
- magnetismus * MeSH
- Saccharomyces cerevisiae cytologie metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
Biocatalyst immobilization is one of the techniques, which can improve whole cells or enzyme applications. This method, based on the fixation of the biocatalyst into or onto various materials, may increase robustness of the biocatalyst, allows its reuse, or improves the product yield. In recent decades, a number of immobilization techniques have been developed. They can be divided according to the used natural or synthetic material and principle of biocatalyst fixation in the particle. One option, based on the entrapment of cells or enzymes into a synthetic polyvinyl alcohol lens with original shape, is LentiKats® immobilization. This review describes the preparation principle of these particles and summarizes existing successful LentiKats® immobilizations. In addition, examples are compared with other immobilization techniques or free biocatalysts, pointing to the advantages and disadvantages of LentiKats®.
For n-butanol production by Clostridium pasteurianum DSM 525, a modified reinforced Clostridium medium was used, where glucose was alternated with glycerol and two kinds of continuous fermentation were tested using suspended and surface immobilized cells on corn stover pieces. A steady state, with butanol productivity of 4.2g/Lh, was reached during the packed-bed continuous fermentation at a dilution rate of 0.44h(-1). The average n-butanol concentration, yield and the ratio of n-butanol/liquid by-products were 10.4g/L, 33 % and 2.5, respectively. Unexpectedly, during continuous fermentation with suspended cells, at a dilution rate of 0.01h(-1), steady-state was not achieved and regular oscillations occurred in all measured variables, i.e. concentrations of glycerol, products and the number of cells stained with the fluorescent dyes carboxy fluorescein diacetate and propidium iodide. A possible explanation for oscillatory/steady-state behavior of suspended/surface-attached cells, respectively, may be specific butanol toxicity (toxicity per cell), which was higher/lower in respective cases, and which might be caused by lower/higher cell numbers respectively in both systems.
- MeSH
- bioreaktory MeSH
- biotechnologie metody MeSH
- Clostridium cytologie metabolismus ultrastruktura MeSH
- fermentace MeSH
- imobilizované buňky cytologie metabolismus ultrastruktura MeSH
- kukuřice setá chemie MeSH
- n-butanol metabolismus MeSH
- odpadní produkty analýza MeSH
- techniky vsádkové kultivace MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
An extremely simple procedure has been developed for the immobilization of Saccharomyces cerevisiae cells on magnetic chitosan microparticles. The magnetic carrier was prepared using an inexpensive, simple, rapid, one-pot process, based on the microwave irradiation of chitosan and ferrous sulphate at high pH. Immobilized yeast cells have been used for sucrose hydrolysis, hydrogen peroxide decomposition and the adsorption of selected dyes.
- MeSH
- barvicí látky metabolismus MeSH
- biodegradace MeSH
- chitosan chemická syntéza chemie MeSH
- imobilizované buňky chemie metabolismus MeSH
- koncentrace vodíkových iontů MeSH
- magnetické jevy MeSH
- magnetismus metody MeSH
- mikrovlny MeSH
- peroxid vodíku metabolismus MeSH
- Saccharomyces cerevisiae chemie metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
Contamination of water by heavy metals represents a potential risk for both aquatic and terrestrial organisms, including humans. Heavy metals in water resources can come from various industrial activities, and drinking water can be ex-post contaminated by heavy metals such as Cu(2+) from house fittings (e.g., water reservoirs) and pipes. Here, we present a new copper biosensor capable of detecting copper ions at concentrations of 1-100 μM. This biosensor is based on cells of a specifically modified Saccharomyces cerevisiae strain immobilized in alginate beads. Depending on the concentration of copper, the biosensor beads change color from white, when copper is present in concentrations below the detection limit, to pink or red based on the increase in copper concentration. The biosensor was successfully tested in the determination of copper concentrations in real samples of water contaminated with copper ions. In contrast to analytical methods or other biosensors based on fluorescent proteins, the newly designed biosensor does not require specific equipment and allows the quick detection of copper in many parallel samples.
- MeSH
- biosenzitivní techniky metody MeSH
- chemické látky znečišťující vodu analýza metabolismus MeSH
- genetické inženýrství MeSH
- imobilizované buňky metabolismus MeSH
- kolorimetrie metody MeSH
- limita detekce MeSH
- měď analýza metabolismus MeSH
- odpadní voda analýza MeSH
- Saccharomyces cerevisiae genetika metabolismus MeSH
- voda analýza MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The aims of the present study were to isolate new yeasts with high extracellular (exo) invertase activity and to investigate the usability of buffer systems as invertase production media by immobilized yeast cells. Among 70 yeast isolates, Cryptococcus laurentii MT-61 had the highest exo-invertase activity. Immobilization of yeast cells was performed using sodium alginate. Higher exo-invertase activity for immobilized cells was achieved in tris-sucrose buffer system (TSBS) compared to sodium acetate buffer system and potassium phosphate buffer system. TSBS was prepared by dissolving 30 g of sucrose in 1 L of tris buffer solution. The optimum pH, temperature, and incubation time for invertase production with immobilized cells were determined as 8.0, 35 °C and 36 h in TSBS, respectively. Under optimized conditions, maximum exo-invertase activity was found to be 28.4 U/mL in sterile and nonsterile TSBS. Immobilized cells could be reused in 14 and 12 successive cycles in sterile and nonsterile TSBS without any loss in the maximum invertase activity, respectively. This is the first report which showed that immobilized microbial cells could be used as a biocatalyst for exo-invertase production in buffer system. As an additional contribution, a new yeast strain with high invertase activity was isolated.
- MeSH
- biotechnologie metody MeSH
- časové faktory MeSH
- Cryptococcus enzymologie metabolismus MeSH
- imobilizované buňky enzymologie metabolismus MeSH
- invertasa izolace a purifikace MeSH
- koncentrace vodíkových iontů MeSH
- kultivační média chemie MeSH
- pufry MeSH
- sacharosa MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
Clostridium acetobutylicum immobilised in polyvinylalcohol, lens-shaped hydrogel capsules (LentiKats(®)) was studied for production of butanol and other products of acetone-butanol-ethanol fermentation. After optimising the immobilisation protocol for anaerobic bacteria, continuous, repeated batch, and fed-batch fermentations in repeated batch mode were performed. Using glucose as a substrate, butanol productivity of 0.41 g/L/h and solvent productivity of 0.63 g/L/h were observed at a dilution rate of 0.05 h(-1) during continuous fermentation with a concentrated substrate (60 g/L). Through the process of repeated batch fermentation, the duration of fermentation was reduced from 27.8h (free-cell fermentation) to 3.3h (immobilised cells) with a solvent productivity of 0.77 g/L/h (butanol 0.57 g/L/h). The highest butanol and solvent productivities of 1.21 and 1.91 g/L/h were observed during fed-batch fermentation operated in repeated batch mode with yields of butanol (0.15 g/g) and solvents (0.24 g/g), respectively, produced per gram of glucose.
- MeSH
- aceton metabolismus MeSH
- anaerobióza MeSH
- butanoly metabolismus MeSH
- Clostridium acetobutylicum cytologie metabolismus MeSH
- ethanol metabolismus MeSH
- fermentace * MeSH
- imobilizované buňky metabolismus MeSH
- techniky vsádkové kultivace metody MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
