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1.
Calcium alginate entrapment of the yeast Rhodosporidium toruloides for the kinetic resolution of 1,2-epoxyoctane 总被引:1,自引:0,他引:1
Resting cells of the yeast Rhodosporidium toruloides (UOFS Y-0471) were immobilised in calcium alginate beads for the enantioselective kinetic resolution of racemic-1,2-epoxyoctane. The initial activity exhibited by immobilised cells was almost 50% lower than that of the free counterpart but was extremely stable when compared to the free cells. The concentration of the immobilised biomass had no effect on apparent enzyme activity but did lead to a decrease in single cell activity. An increase in both the alginate and CaCl2 concentrations used for bead preparation led to a decrease in enzyme stability. An increase in the alginate concentration led to an increase in bead diameter. The stoichiometric equation for cross-linking of alginate was only obeyed when CaCl2 concentrations higher than 0.4 M were utilised for bead preparation. 相似文献
2.
A. K. Singh M. Sharma R. Varshney S. S. Agarwal K. C. Bansal 《In vitro cellular & developmental biology. Plant》2006,42(2):109-113
Summary A method was developed for plant regeneration from alginate-encapsulated shoot tips of Phyllanthus amarus. Shoot tips excised from in vitro proliferated shoots were encapsulated in calcium alginate beads. The best gel complexation was achieved using 3% sodium alginate
and 75 mM CaCl2·2H2O. Maximum percentage response for conversion of encapsulated shoot tips into plantlets was 90% after 5 wk of culture on Murashige
and Skoog (MS) medium without plant growth regulator. The regrowth ability of encapsulated shoot tips was affected by the
concentration of sodium alginate, storage duration, and the presence or absence of MS nutrients in calcium alginate beads.
Plantlets with well-developed shoot and roots were transferred to pots containing an autoclaved mixture of soilrite and peat
moss (1∶1). The conversion of encapsulated shoot tips into plantlets also occurred when calcium alginate beads were directly
sown in autoclaved soilrite moistened with 1/4-MS salts. Encapsulation of vegetative propagules in calcium alginate beads
can be used as an alternative to synthetic seeds derived from somatic embryos. 相似文献
3.
Soo Hwan Cheong Joong Kon Park Beom Soo Kim Ho Nam Chang 《Biotechnology Techniques》1993,7(12):879-884
Summary Cells of Saccharomyces cerevisiae (ATCC 24858) were encapsulated in the calcium alginate membrane and cultured. Swelling of the capsule was prevented by adding 0.2 g CaCl2 to 1 L growth medium. The dry cell concentration based on the inner volume of the capsule reached 309 g/L, which was much higher than could be obtained by cell entrapment. All the cells remained inside the capsule during the cultivation. The flux of CO2 through the capsule membrane increased approximately twice by adding a nonionic surfactant to the CaCl2 solution during the step of capsule formation. 相似文献
4.
Saccharomyces cerevisiae cells were immobilized in calcium alginate beads for use in the continuous production of ethanol. Yeasts were grown in medium supplemented with ethanol to selectively screen for a culture which showed the greatest tolerance to ethanol inhibition. Yeast beads were produced from a yeast slurry containing 1.5% alginate (w/v) which was added as drops to 0.05M CaCl2 solution. To determine their optimum fermentation parameters, ethanol production using glucose as a substrate was monitored in batch systems at varying physiological conditions (temperature, pH, ethanol concentration), cell densities, and gel concentration. The data obtained were compared to optimum free cell ethanol fermentation parameters. The immobilized yeast cells examined in a packed-bed reactor system operated under optimized parameters derived from batch-immobilized yeast cell experiments. Ethanol production rates, as well as residual sugar concentration were monitored at different feedstock flow rates. 相似文献
5.
Summary The optimum conditions forAcetobacter immobilization were investigated. The results show that: 1) the maximum oxygen uptake rate (OURm) and cell release are related to alginate and cell concentration in the gel; 2)different alginate concentration does not affect cell viability, but long storage in CaCl2 reduces the number of living cells; 3)the double alginate gel layers had no influence on cell viability and on the OURm and prevented cell leakage from the gel matrix. 相似文献
6.
Dr. Figen Ertan Hulya Yagar Bilal Balkan 《Preparative biochemistry & biotechnology》2013,43(3):195-204
Abstract α‐Amylase enzyme was produced by Aspergillus sclerotiorum under SSF conditions, and immobilized in calcium alginate beads. Effects of immobilization conditions, such as alginate concentration, CaCl2 concentration, amount of loading enzyme, bead size, and amount of beads, on enzymatic activity were investigated. Optimum alginate and CaCl2 concentration were found to be 3% (w/v). Using a loading enzyme concentration of 140 U mL?1, and bead (diameter 3 mm) amount of 0.5 g, maximum enzyme activity was observed. Beads prepared at optimum immobilization conditions were suitable for up to 7 repeated uses, losing only 35% of their initial activity. Among the various starches tested, the highest enzyme activity (96.2%) was determined in soluble potato starch hydrolysis for 120 min at 40°C. 相似文献
7.
Luciana da Silva Rodrigues Maria Catarina Megumi Kasuya Arnaldo Chaer Borges 《Mycorrhiza》1999,8(5):263-266
We studied the viability of fragmented mycelium of Pisolithus
tinctorius and Paxillus
involutus entrapped in calcium alginate gel to determine the efficacy of this method of producing ectomycorrhizal fungus inoculum.
Fungi were grown in MMN solution at 28 °C before being fragmented in a blender and subsequently entrapped in calcium alginate.
We tested different ratios of alginate and mycelium suspension to 0.7 M CaCl2. The ratio 8 : 10 resulted in well-formed beads of the highest viability for Paxillus involutus (99%) and for Pisolithus tinctorius (75%). Paxillus
involutus mycelium was more than 90% viable when entrapped mycelium was 10 to 50 days old, and Pisolithus tinctorius attained its highest viability (55%) for 20- to 40-day-old mycelium. Gel entrapped Paxillus
involutus mycelium grew well at all temperatures after 30 days of storage, but viability significantly decreased after 60 days storage
at 6 °C on dry filter paper. For gel-entrapped Pisolithus tinctorius mycelium, viability was highest when stored at 25 °C in 0.7 M CaCl2. Entrapment of Paxillus
involutus fragmented mycelium in calcium alginate beads under the conditions that we propose can be used successfully to produce inoculum.
Accepted: 11 October 1998 相似文献
8.
Summary The dissolution of alginate gel beads in 20 g sodium citrate /l produces a linear decrease in bead diameter. The rate of dissolution is dependent on the concentration of CaCl2 within the gel beads. This method allows the controlled release of Saccharomyces cerevisiae from alginate gel beads and permits the simple and rapid determination of the radial distribution of cell concentration. 相似文献
9.
M. Wallbraun K. Sonntag C. Eisenhauer G. Krzcal Y. P. Wang 《Plant Cell, Tissue and Organ Culture》2009,99(3):345-351
Nodal segments (4 ± 1 mm long) of Hibiscus moscheutos (hardy hibiscus) were excised from in vitro proliferating microshoots and utilized to evaluate initial factors involved in
bulk alginate encapsulation. The factors evaluated were; storage vessel type, volume and multiple rinse effects of CaCl2 solutions, and sodium alginate concentrations (2.5, 2.75, 3.0 or 3.25%) for bulk alginate encapsulation. Results indicate
that vessels utilized for bulk alginate encapsulation should have a lower base area (L × W) to height ratio to reduce the amount of alginate matrix shrinkage resulting in exposure of nodal segments. Increased volumes
and multiple 50 mM CaCl2 solution rinses did not have an effect on alginate solidification. Shoot length, root number, and root length significantly
decreased in a linear manner from nodal explants stored for 4 weeks with increasing concentrations of sodium alginate. This
research suggests an innovative technique for alginate encapsulation of H. moscheutos utilizing bulk methods as an alternative to single bead alginate encapsulation. 相似文献
10.
The optimum critical parameters for immobilization of Streptomyces clavuligerus on alginate gel matrix for cephamycin C production, i.e. sodium alginate (wt. %), CaCl2 (M) and cell concentration (wt. %), curing time (h.), for enhanced gel stability, were obtained employing a full factorial search. The results indicate that the concentrations of CaCl2 and inoculum size were found to have a pronounced effect on cephamycin C fermentation. On the other hand, the higher concentration of sodium alginate exerted an adverse influence either individually or in combination with other variables. The path steepest ascent method has been used to optimize the variables. The optimum concentrations of matrix components were 3.218% sodium alginate, 0.996 M CaCl2, 19.06% cell concentration and 17.16 h. of curing time supported higher cephamycin C production, at 48 h. of fermentation. 相似文献
11.
A reliable cryopreservation technique was developed for friable embryogenic callus lines of Hevea brasiliensis. The study showed that reducing the CaCl2 concentration of the pre-culture medium from 9 mM to 1 or 0 mM CaCl2 before cryopreservation promoted post-thaw callus growth, 1 mM being the optimum CaCl2 concentration for embryo regeneration. Post-thaw callus proliferation decreased in line with the increase of plated callus
weight. The effect of cryopreservation was assessed on 39 independent lines showing that cryopreservation did not affect embryogenic
and plant regeneration for a majority of lines. The decrease in CaCl2 concentration of the pre-culture medium led to a drop in callus calcium content indicating a direct link between the CaCl2 concentration of the pre-culture medium and the endogenous calcium content of the calli. It also highlighted the implication
of tissue calcium content in cryotolerance. Callus water status and the different ways by which calcium could prevent cryoinjury
is also discussed. 相似文献
12.
Carica papaya L. (papaya) single somatic embryos (2.0 mm diameter) produced in a high-frequency liquid production system were encapsulated
in two different synthetic encapsulation compounds. The frequency of regeneration from encapsulated embryos was significantly
affected by (1) the concentration of sodium alginate, (2) the presence or absence of nutrient salts in the capsule, and (3)
the duration of exposure to calcium chloride. A 2.5% sodium alginate concentration in a half-strength MS salts base resulted
in significantly higher germination frequencies than other treatments. A relatively short (10 min) exposure to CaCl2 provided uniform encapsulation of embryos and the highest frequencies of successful germination (77.5%). Germinated artificial
seeds produced normal plantlets.
Received: 12 March 1997 / Revision recieved: 24 June 1997 / Accepted: 18 July 1997 相似文献
13.
Mesophyl cell protoplasts of Vicia faba were suspended in a solution consisting of 10% sodium alginate and 0.4 M mannitol. The protoplasts could be immobilized by cross-linking the alginate in the presence of 100 mM CaCl2. Changes in the osmolarity of the external medium led to reversible shrinkage and swelling of the entrapped protoplasts. It was demonstrated by using the pressure probe technique that a pressure gradient (cell turgor pressure) of several 100 mbar is built up when the immobilized cells were transferred to hypotonic solution. By complexing the Ca2+ in the alginate matrix with sodium citrate buffer the protoplasts could be released from the matrix. No morphological change or alteration of the membrane permeability of the immobilized protoplasts was observed after a storage period of up to 14 days at 4°C in the matrix. 相似文献
14.
Garbayo I Vílchez C Vega JM Nava-Saucedo JE Barbotin JN 《Biotechnology letters》2004,26(23):1825-1827
Streptococcus thermophilusand Lactobacillus bulgaricus were co-immobilized in different systems with varying calcium (0.1–1.5M) and alginate (1–2<><>, w/v) concentrations. Highest lactic acid production was 35 g l1 when both bacteria were in high viscosity beads (1<><>, w/v alginate) hardened in 0.1 M CaCl2 .The gel bead composition affected size and distribution of entrapped lactic acid bacteria. 相似文献
15.
Takashi Sakaguchi Akira Nakajima Takao Horikoshi 《Applied microbiology and biotechnology》1981,13(2):84-89
Summary Cells of a Daucus carota suspension culture were entrapped in a matrix of calcium alginate. The immobilised cells, incubated in a buffer mixture of
sucrose, nitrate, KCl, CaCl2, 2-(N-morpholino)-ethane sulphonic acid at pH 5.5, hydroxylated digitoxigenin. When compared under the same incubation conditions,
freely suspended cells biotransformed digitoxigenin at a faster rate. Periplogenin formation was maximal at pH 5.3 and temperatures
of 26°–34°C. The hydroxylase activity of the entrapped cells adapted to the presence of 20 mM CaCl2 over a 12 day incubation. The diffusion barrier established on entrapment of the cells could not be overcome by addition
of detergents or methanol. Controlled addition of chloroform (at 1/4 and 1/2 saturation) did stimulate hydroxylation of digitoxigenin
without adversely affecting cell viability. The rate of hydroxylation of digitoxigenin was linear over an immobilised cell
concentration of 0–7 mg dry weight and a digitoxigenin concentration of 0–20 mg/L. Five consecutive batch bioconversions at
a rate greater than 60% could be achieved before the biocatalyst was inactivated. The results are discussed in relation to
improving the hydroxylation reaction by immobilised D. carota and other reactions performed by immobilised plant cells. 相似文献
16.
Ruphi Naz Mohammad Anis Abdulrahman A. Alatar Altaf Ahmad Afshan Naaz 《Plant biosystems》2013,147(6):1256-1262
AbstractIn the present study, an alternate method for germplasm storage in the form of artificial seeds was standardized via nodal explants excised from in vitro proliferated shoots. The explants were encapsulated using sodium alginate and calcium chloride as gelling matrix. For development of root along with shoot, excised nodal segments were pretreated with ½ MS medium along with 20 μM IBA for 24 h and encapsulation was carried thereafter. Combination of 3% sodium alginate augmented with 100 mM CaCl2.2H2O was found appropriate for the formation of clear and uniform beads and subsequent conversion of encapsulated nodal segments into plantlets. Maximum (66%) encapsulated nodal segments were converted into plantlets on MS medium supplemented with 7.5 μM BA and 0.5 μM NAA after eight weeks. Regeneration frequency of auxin-pretreated encapsulated and non-encapsulated nodal segments (stored at 4 ºC) was evaluated at different storage time (0 to 6 weeks). After four weeks of storage, encapsulated propagules exhibited highest conversion response on the optimized medium after eight weeks of culture. Plantlets were hardened and established with success in ex vitro conditions. Conversion of synthetic seeds into plantlets was observed when these were directly sown in autoclaved SoilriteTM (Keltech Energies, Bangalore, India). 相似文献
17.
Artificial seeds were obtained through encapsulation of protocorm-like bodies (PLBs) of Dendrobium densiflorum in calcium alginate beads. This paper demonstrates the alginate-encapsulation and conversion (complete plantlet regeneration) from PLBs, the effect of storage conditions (at different temperature; 4, 8, 16 °C, RT and duration; 15, 30, 45, 60, 75, 90 days) on viability of encapsulated plant materials as well as the assessment of genetic fidelity of the regenerants. Individual PLBs were encapsulated in calcium alginate beads for mass propagation, short-term storage and germplasm sharing. The superior gel matrix for encapsulation was obtained using 3 % sodium alginate and 100 mM calcium chloride (CaCl2·2H2O). The highest percentage of conversion (100 %) of encapsulated PLBs (capsules) was obtained on MS2 medium (MS medium + 2 mg/l BAP). Capsules were successfully stored till 60 days at 8 °C with conversion frequency of 95.5 %. Plantlets regenerated from encapsulated beads were acclimatized successfully with 95 % survival rate. A total of 40 primers were screened, out of which 10 primers successfully generated 39 scorable bands, ranging from 0.2 to 1.3 kb amplicons. The uniform RAPD banding profile among the plantlets derived from encapsulated PLBs following 60 days of storage confirmed genetic fidelity. 相似文献
18.
The purpose of this investigation was to study the effect ofStreptomyces marinensis NUV-5 cells immobilized in calcium alginate for the production of neomycin. The effect of various parameters, such as the
effect of alginate concentration (1%, 2%, 3%, 4%, and 5% wt/vol), the effect of cation (caCl2, BaCl2, and SrCl2), the concentration of cation (0.01M, 0.125M, 0.25M, 0.375M, and 0.5M), the curing times (1, 6, 11, 16, and 21 hours), and
the diameter of the bead (1.48, 2.16, 3.24, 4.46, and 5.44 mm), on neomycin production and bead stability were studied. The
effect of maltose (4%, 3%, 2%, and 1% wt/vol) and sodium glutamate (0.6%, 0.3%, 0.15%, and 0.075%) wt/vol) concentration on
neomycin production was also studied. Better neomycin production was achieved with optimized parameters, such as alginate
at 2% wt/vol, 0.25M CaCl2, 1-hour curing time, and 3.24 mm bead diameter. Effective neomycin production was achieved with 3% wt/vol maltose and 0.6%
wt/vol sodium glutamate concentration. The repeated batch fermentations were conducted (every 96 hours) using the optimized
alginate beads, employing the production medium with 3% wt/vol maltose and 0.6% wt/vol sodium glutamate along with minerals
salts solution. The increase in antibiotic production was observed up to the 5th cycle, and later gradual decrease in antibiotic
production was observed. Comparison of the total antibiotic production with free cells and immobilized cells was also done.
An enhanced antibiotic productivity of 32% was achieved with immobilized cells over the conventional free-cell fermentation,
while 108% more productivity was achieved over the washed free-cell fermentation. From these results it is concluded that
the immobilized cells ofS marinensis NUV-5 in calcium alginate are more efficient for the production of neomycin with repeated batch fermentation. 相似文献
19.
4-Nitrophenol degrading bacterial strainCorynebacterium sp. 8/3 was isolated from chemically polluted soil. The product of cometabolic transformation of 4-nitrophenol was identified
as 4-nitrocatechol., Effect of immobilization (encapsulation in calcium alginate) ofCorynebacterium sp. cells on the process of 4-nitrophenol transformation was investigated. 4-Nitrophenol was converted by encapsulated cells
and encapsulation had a protective effect, on 4-nitrophenol degrading bacteria in repeated cycles of incubation. Transformation
of 4-nitrophenol to 4-nitrocatechol by encapsulated cells was influenced by pH of medium but was not influenced by concentration
of alginate and CaCl2. The count of viable cells in alginate beads declined approximately by one order of magnitude after 10 d of incubation.
Presented at the 4th Mini-Symposium on Biosorption and Microbial Degradation, Prague, Czech Republic, November 26–29, 1996. 相似文献
20.
Summary Protocorm-like bodies (plbs) of the orchid Dendrobium ‘Sonia’ were obtained from fractionated plb explants on Murashiga and Skoog (1962) medium (MS) supplemented with 4.44 μM 6-benzylaminopurine (BA). The developmental stage of plbs to be encapsulated, concentrations of sodium alginate (2–5%) and
calcium chloride (25–100 mM), and concentration of MS salts in the matrix were assessed. Fractionated plbs 13–15 d after culture were at the leaf primordia
stage and found suitable for encapsulation studies. The best encapsulation response was observed with 3% sodium alginate upon
complexation with 75 mM CaCl2.2H2O. An encapsulation matrix prepared with MS medium (three-quarter strength) supplemented with 0.44 μM BA and 0.54 μM α-naphthaleneacetic acid gave 100% conversion of encapsulated plbs to plants after storage. A viability of >85% of encapsulated
plbs of Dendrobium ‘Sonia’ was observed for 75 d at 4°C. Encapsulated plbs of orchids Dendrobium, Oncidium, and Cattleya were stored at 4°C for 75, 60 and 30 d, respectively, with >88% germination. All plants survived potting in media having
either wood charcoal pieces alone or in combination with brick pieces. 相似文献