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1.
Wayne B. Hunter 《In vitro cellular & developmental biology. Animal》2010,46(2):83-86
A media for the production of cell cultures from hymenopteran species such as honey bee, Apis mellifera L. (Hymenoptera: Apidae) was developed. Multiple bee cell cultures were produced when using bee larvae and pupae as starting
material and modified Hert–Hunter 70 media. Cell culture systems for bees solves an impasse that has hindered efforts to isolate
and screen pathogens which may be influencing or causing colony collapse disorder of bees. Multiple life stages of maturing
larvae to early pupae were used to successfully establish cell cultures from the tissues of the head, thorax, and abdomen.
Multiple cell types were observed which included free-floating suspensions, fibroblast-like, and epithelia-like monolayers.
The final culture medium, WH2, was originally developed for hemipterans, Asian citrus psyllid, Diaphorina citri, and leafhopper, Homalodisca vitripennis cell cultures but has been shown to work for a diverse range of insect species such as bees. Bee cell cultures had various
doubling times at 21–23°C ranging from 9–15 d. Deformed wing virus was detected in the primary explanted tissues, which tested
negative by rt-PCR for Israeli acute paralysis virus (IAPV), Kashmir bee virus, acute bee paralysis virus, and black queen
cell virus. Culture inoculation with IAPV from an isolate from Florida field samples, was detectable in cell cultures after
two subcultures. Cell culture from hymenoptera species, such as bees, greatly advances the approaches available to the field
of study on colony collapse disorders. 相似文献
2.
Arun M. Khurad Min-Juan Zhang Chanchal G. Deshmukh Ravindra S. Bahekar Ashish D. Tiple Chuan-Xi Zhang 《In vitro cellular & developmental biology. Animal》2009,45(8):414-419
A new continuous cell line from ovarian tissue of commercial variety “Kolar Gold” of silkworm, Bombyx mori, was established and designated as DZNU-Bm-12. The tissue was grown in MGM-448 insect cell culture medium supplemented with
10% fetal bovine serum (FBS) and 3% heat-inactivated B. mori hemolymph at 25 ± 1°C. The migration of partially attached small round refractive cells from the fragments of ovarioles began
from the beginning of explantation. The cells multiplied partially attached in the primary culture initially, and some of
them become freely suspended after 20 passages. The cells were adapted to MGM-448 and TNM-FH media each with 10% FBS and the
population doubling time of cell line was about 36 and 24 hr, respectively. The chromosome number was near diploid at initial
passages and slightly increased at 176th passage, but a few tetraploids and hexaploids were also observed. DNA profiles using
simple sequence repeat loci established the differences between DZNU-Bm-12 and DZNU-Bm-1 and most widely used Bm-5 and BmN
cell lines. The cell line was found susceptible to B. mori nucleopolyhedrovirus (BmNPV) with 85–90% of the cells harboring BmNPV and having an average of 3–17 OBs/infected cell. We
suggest the usefulness of this cell line in BmNPV-based baculoviral expression system and also for studying in vitro virus
replication. 相似文献
3.
T. Dennis Thomas 《In vitro cellular & developmental biology. Plant》2009,45(5):591-598
Protoplast culture and plant regeneration of an important medicinal plant Tylophora indica were achieved through callus regeneration. Protoplasts were isolated from leaf mesophyll cells and cultured at a density
of 5 × 105 protoplasts per gram fresh weight, which is required for the highest frequency of protoplast division (33.7%) and plating
efficiency (9.3%). The first division was observed 2 d after plating and the second division after 4 d. Culture medium consists
of Murashige and Skoog (MS) liquid medium with 4 μM 2,4-D, 0.4 M mannitol and 3% (w/v) sucrose with pH adjusted to 5.8. After 45 d of culture at 25°C in the dark, protoplasts formed colonies consisting of about
100 cells. The protoplast-derived microcalli were visible to the naked eye within 60 d of culture and reached a size of 0.2–0.4 mm
in diameter after 90 d. Calli of 0.2–0.4-mm size were transferred to MS medium supplemented with 2,4-D (4 μM), 3% (w/v) sucrose and 0.8% (w/v) agar, formed friable organogenic calli (7-8 mm size) after 8 wk under incubation in normal light period supplemented with
200 μmol m−2 S−1 of day light fluorescent illumination. The calli were transferred to MS medium supplemented with thidiazuron (TDZ) (1–7 μM)
and naphthalene acetic acid (NAA) (0.2–0.4 μM) for regeneration. The calli developed shoot buds after 3–4 wk, and the frequencies
of calli-forming shoots varied from 5% to 44%. Optimum shoot regeneration occurred on MS medium supplemented with 5 μM TDZ
and 0.4 μM NAA. On this medium, 44% cultures responded with an average number of 12 shoots per callus. Whole plants were recovered
following rooting of shoots in 1/2 MS medium supplemented with 3 μM indole 3-butyric acid. 相似文献
4.
Abhinav Grover Jayashankar S. Yadav Ranjita Biswas Choppakatla S. S. Pavan Punita Mishra Virendra S. Bisaria Durai Sundar 《Plant Cell, Tissue and Organ Culture》2012,108(2):323-331
Cell suspension cultures of Camellia sinensis were established in 250 ml shake flasks. Flasks contained 50 ml liquid medium of either Murashige and Skoog (MS), N/5 MS
or Heller medium containing different levels of 6-benzyladenine (BA) (0.05–2 mg l−1), 2,4-dichlorophenoxyacetic acid (2,4-D) (1–10 mg l−1), and sucrose (10–50 g l−1). Moreover, the pH of the medium was varied from 5.2–6.2. In addition, cultures were subjected to light irradiation as well
as to complete darkness. Following optimization of aroma and terpenoid extraction methods, cell cultures were analyzed for
the volatile compounds using GC/MS. A total of 43 compounds were identified using the micro SDE apparatus. Among the major
monoterpenoids obtained were α-terpineol and nerol. Moreover, other high aroma-value compounds, including 2-ethyl hexanol,
benzyl alcohol, benzene acetaldehyde, nonanal and phenylethylalcohol were also detected. The highest levels of these compounds
were obtained from cell suspension cultures grown in MS medium containing 5 mg l−1 2,4-D, 1 mg l−1 BA and 30 g l−1 sucrose at pH of 5.8 with incubation in complete darkness. 相似文献
5.
Ling Li Jun Qin Qiang Feng Hao Tang Rong Liu Liqing Xu Zhinan Chen 《Molecular biotechnology》2011,47(1):9-17
While heparin has been shown to eliminate cell aggregation in suspension adaptations of insect and HEK293 cells for virus-based
cell cultures, the role of heparin in long period serum-free suspension adaptation of the anchorage-dependent Chinese hamster
ovary (CHO) cell lines remains inconclusive. In this paper, we explore the potential application of heparin in suspension
adaptation of CHO cell line which produces an anti-human chimeric antibody cHAb18. Heparin showed a concentration-dependent
inhibition of CHO–TS28 cell-to-cell adhesion, with a significant inhibitory effect occurring when the concentration exceeded
250 μg/ml (P < 0.001). Heparin also exhibited a cell aggregation elimination role at all concentrations (P < 0.001). Furthermore, heparin promoted cell growth and antibody secretion, with the highest cell density ((99.83 ± 12.21) × 104 cells/ml, P = 0.034) and maximum antibody yield ((9.46 ± 0.94) mg/l, P < 0.001) both occurring at 250 μg/ml heparin. When agitated, cell aggregates were effectively dispersed by 250 μg/ml heparin
and a single-cell suspension culture process was promoted. In suspension adapted CHO–TS28 cells, cell growth rates and specific
antibody productivity were maintained; while antigen-binding activity improved slightly. Together, our results show that heparin
may promote suspension adaptation of anchorage-depended CHO cells by resisting cell aggregation without reducing cell growth,
antibody secretion, and antigen-binding activity. 相似文献
6.
Solovchenko A Khozin-Goldberg I Recht L Boussiba S 《Marine biotechnology (New York, N.Y.)》2011,13(3):527-535
In order to develop a practical approach for fast and non-destructive assay of total fatty acid (TFA) and pigments in the
biomass of the marine microalga Nannochloropsis sp. changes in TFA, chlorophyll, and carotenoid contents were monitored in parallel with the cell suspension absorbance.
The experiments were conducted with the cultures grown under normal (complete nutrient f/2 medium at 75 μmol PAR photons/(m2 s)) or stressful (nitrogen-lacking media at 350 μmol PAR photons/(m2 s)) conditions. The reliable measurement of the cell suspension absorbance using a spectrophotometer without integrating
sphere was achieved by deposition of cells on glass–fiber filters in the chlorophyll content range of 3–13 mg/L. Under stressful
conditions, a 30–50% decline in biomass and chlorophyll, retention of carotenoids and a build-up of TFA (15–45 % of dry weight)
were recorded. Spectral regions sensitive to widely ranging changes in carotenoid-to-chlorophyll ratio and correlated changes
of TFA content were revealed. Employing the tight inter-correlation of stress-induced changes in lipid metabolism and rearrangement
of the pigment apparatus, the spectral indices were constructed for non-destructive assessment of carotenoid-to-chlorophyll
ratio (range 0.3–0.6; root mean square error (RMSE) = 0.03; r
2 = 0.93) as well as TFA content of Nannochloropsis sp. biomass (range 5.0–45%; RMSE = 3.23 %; r
2 = 0.89) in the broad band 400–550 nm normalized to that in chlorophyll absorption band (centered at 678 nm). The findings
are discussed in the context of real-time monitoring of the TFA accumulation by Nannochloropsis cultures under stressful conditions. 相似文献
7.
Johnius (Johnius) majan sp. nov. is described on the basis of 8 specimens (117–158 mm in standard length) from Oman, Indian Ocean. The new species
is distinguished from its congeners by the following combination of characters: black axillary spot on upper pectoral fin
base; dorsal soft rays 29–32; anal soft rays 8; scales above lateral line 6, below 11; eye diameter 22.9–28.9% HL; interorbital
width 32.0–38.0% HL; gill rakers 5–6 + 15–18 = 21–24; no mental barbel; last well developed pleural rib on 7th vertebra; swim
bladder appendages 11; vertebrae 10 + 14 = 24. 相似文献
8.
T/Tn specificity of Artocarpus lakoocha agglutinin (ALA), isolated from the seeds of A. lakoocha (Moraceae) fruit and a heterodimer (16 kD and 12 kD) of molecular mass 28 kD, was further confirmed by SPR analysis using
T/Tn glycan containing mammalian glycoproteins. N-terminal amino acid sequence analysis of ALA showed homology at 15, 19–21,
24–27, and 29 residues with other lectin members of Moraceae family viz., Artocarpus integrifolia (jacalin) lectin, Artocarpus hirsuta lectin, and Maclura pomifera agglutinin. It is mitogenic to human PBMC and the maximum proliferation was observed at 1 ng/ml. It showed an antiproliferative
effect on leukemic cells, with the highest effect toward Jurkat cells (IC50 13.15 ng/ml). Synthesized CdS quantum dot-ALA nanoconjugate was employed to detect the expression of T/Tn glycans on Jurkat,
U937, and K562 leukemic cells surfaces as well as normal lymphocytes by fluorescence microscopy. No green fluorescence was
observed with normal lymphocytes indicating that T/Tn determinants, which are recognized as human tumor associated structures
were cryptic on normal lymphocyte surfaces, whereas intense green fluorescent dots appeared during imaging of leukemic cells,
where such determinants were present in unmasked form. The above results indicated that QD-ALA nanoconjugate is an efficient
fluorescent marker for identification of leukemic cell lines that gives rise to high quality images. 相似文献
9.
Shainn-Wei Wang William J. McCarthy 《In vitro cellular & developmental biology. Animal》1997,33(4):315-323
Summary A sensitive lactate dehydrogenase (LDH) assay was modified to determine the cytolytic activity of Bacillus thuringiensis CryIC and CryIAc delta endotoxins to viable collagenase-dissociated midgut epithelial cells (MEC) from larvae of Spodoptera frugiperda and Spodoptera exigua. The MEC preparations from these Spodoptera sp. consisted predominantly of columnar cells (65–75%) and goblet cells (25–35%). Time course microscopy experiments indicated
that only the columnar cells became swollen during CryIC toxin incubation. Also, comparative cytotoxicity studies were run
with cell lines of nonmidgut origin established from S. frugiperda (SF21AE) and S. exigua (SEUCR1A). Optimum conditions for the cytotoxicity assay were similar for MEC and cell lines of both species, and were met
in an assay in which 0.1-ml cell concentrations (8.5±0.5×104 cells) were incubated with toxin dilutions (0.01–20 μg) for 1 h at 24° C at a final pH of 7.8.
The Spodoptera sp. MEC were twofold more sensitive to CryIC (68% lysis) than CryIAc (32% lysis) at optimum toxin levels (2.5–5 μg). Also,
the SEUCR1A cells were more sensitive (2.3-fold) to CryIC (70% lysis) than CryIAc (30% lysis) at optimum toxin levels of 5–10
μg. The SF21AE cells, however, were twofold less sensitive to CryIC (30% lysis) than SEUCR1A cells and response to CryIAc
and CryIC was similar.
Immunoblot analysis of either Spodoptera sp. MEC or brush border membrane vesicles (BBMV) identified seven CryIC binding proteins with molecular mass of 137, 120,
115, 68, 65, 63, and 45 kDa. Occasionally, a 148-kDa protein band was observed. The CryIAc toxin bound to two proteins on
MEC and BBMV with molecular mass of 137 and 120 kDa. 相似文献
10.
11.
Stolephorus teguhi sp. nov. is described from the holotype and 14 paratypes, 49–77 mm in standard length, collected from North Sulawesi, Indonesia.
The species is characterized by having numerous gill rakers (31–35 + 41–46 = 72–82) and a short upper jaw, its posterior tip
reaching to or extending slightly beyond the anterior margin of the preopercle. Stolephorus pacificus and S. multibranchus also have relatively numerous gill rakers for species of this genus (21–27 + 29–36 = 53–61 and 21–28 + 30–35 = 54–60, respectively),
but counts for S. teguhi exceed those for the two species. Although S. advenus also has a short upper jaw similar to that of S. teguhi, the former has far fewer gill rakers (19 + 24 = 43) than the latter. 相似文献
12.
Fayuan Wen Yong-an Zhang Liangjian Qu Huan Zhang Zhongqi Yang Qilian Qin Yuzhu Wang Wenhuan Wang 《In vitro cellular & developmental biology. Animal》2009,45(8):409-413
Two cell lines designated CAF-Clan I and CAF-Clan II have been established from embryos of Clostera anachoreta (Lepidoptera: Notodontidae) in TNM-FH medium containing 10% inactivated fetal bovine serum. CAF-Clan I consists of a mixture
of three cell types: spherical cells, spindle-shaped cells, and giant cells. Most of the cultured cells formed a suspension
in the medium and were subcultured more than 60 passages. CAF-Clan II mainly consists of spindle-shaped and spherical cells
which attached to the culture surface and have undergone more than 40 passages. The cell population doubling time at 27°C
of CAF-Clan I at passage 22 and CAF-Clan II at passage 24 was about 68.5 and 38.2 h, respectively. The chromosome number of
both cell lines at passage 15 varied from 62 to 100 in the majority of cells, though a few cells exceeded 260 (n = 30). DNA amplification fingerprinting–polymerase chain reaction analysis confirmed that the origination of the two cell
lines was C. anachoreta. The susceptibility of the cell lines to baculoviruses was tested. The results showed that CAF-Clan II was susceptible to
infection of Autographa californica nucleopolyhedrovirus (AcMNPV) and Ecotropis oblique nucleopolyhedrovirus (EoNPV). Occlusion bodies (OBs) production was 129 ± 4 OBs/cell and 124 ± 15 OBs/cell for AcMNPV and
EoNPV, respectively. CAF-Clan I was less susceptible to AcMNPV compared with CAF-Clan II, while non-permissive to EoNPV. 相似文献
13.
Protoplasts were isolated enzymatically from the carrageenophyte red alga Grateloupia turuturu (Halymeniales, Rhodophyta) that occurs along the coast of the French Channel in Normandy. Effects of the main factors on
the protoplast yield were identified to improve the isolation protocol. The optimal enzyme composition for cell wall digestion
and protoplast viability consisted of 2% cellulase Onozuka R-10, 0.5% macerozyme R-10, 2% crude extract from viscera of Haliotis tuberculata, 0.8 M mannitol, 20 mM sodium citrate, 0.3% bovine serum albumin at 25°C, and 4-h incubation period. The protoplasts were
approximately 5–15 μm in diameter, liberated mainly from the surface cell layers. Maximum yield was 1.5 × 107 protoplasts g-1 fresh tissue. The protoplasts underwent initial division after 14 days with a high density level of 1 × 106 cells mL-1 in culture medium and developed into microthalli of a line of two to six cells. 相似文献
14.
Ampullary organs of Euristhmus lepturus occur in high densities along the head and in four parallel pathways along the trunk of the body. Large ampullary pores (125–130 μm)
are easily distinguishable from other sensory epithelial pores due to the differences in size and the presence of a collar-like
structure. Simple, singular ampullary organs of the head region consist of an ampullary pore connected to a long canal with
a diameter of 115–175 μm before terminating as a simple ampulla with an external diameter of 390–480 μm. The ampullary canal
is composed of 1–2 layers of flattened squamous epithelial cells, the basement membrane and an interlocking collagen sheath.
The innermost cells lining the canal wall are adjoined via tight junctions and numerous desmosomes, as are those of the receptor
and supportive cells. Canal wall tissue gives rise to a sensory epithelium containing between 242 and 285 total receptor cells,
with an average diameter of 11.7 ± 5.3 μm, intermixed with medially nucleated supportive cells. Each receptor cell (21.38 ± 4.41 μm,
height) has an apically positioned nucleus and a luminal surface covered with numerous microvilli. Neural terminals abut the
basal region of receptor cells opposite multiple presynaptic bodies and dense mitochondria. Supportive cells extend from the
ampullary lumen to the basement membrane, which is adjacent to the complex system of collagen fibres. 相似文献
15.
S. H. Mousavi Z. Tayarani-Najaran M. Asghari H. R. Sadeghnia 《Cellular and molecular neurobiology》2010,30(4):591-598
The serum/glucose deprivation (SGD)-induced cell death in cultured PC12 cells represents a useful in vitro model for the study
of brain ischemia and neurodegenerative disorders. Nigella sativa L. (family Ranunculaceae) and its active component thymoquinone (TQ) has been known as a source of antioxidants. In the present
study, the protective effects of N. sativa and TQ on cell viability and reactive oxygen species (ROS) production in cultured PC12 cells were investigated under SGD
conditions. PC12 cells were cultured in DMEM medium containing 10% (v/v) fetal bovine serum, 100 units/ml penicillin, and
100 μg/ml streptomycin. Cells were seeded overnight and then deprived of serum/glucose for 6 and 18 h. Cells were pretreated
with different concentrations of N. sativa extract (15.62–250 μg/ml) and TQ (1.17–150 μM) for 2 h. Cell viability was quantitated by MTT assay. Intracellular ROS production
was measured by flow cytometry using 2′,7′-dichlorofluorescin diacetate (DCF-DA) as a probe. SGD induced significant cells
toxicity after 6, 18, or 24 h (P < 0.001). Pretreatment with N. sativa (15.62–250 μg/ml) and TQ (1.17–37.5 μM) reduced SGD-induced cytotoxicity in PC12 cells after 6 and 18 h. A significant increase
in intracellular ROS production was seen following SGD (P < 0.001). N. sativa (250 μg/ml, P < 0.01) and TQ (2.34, 4.68, 9.37 μM, P < 0.01) pretreatment reversed the increased ROS production following ischemic insult. The experimental results suggest that
N. sativa extract and TQ protects the PC12 cells against SGD-induced cytotoxicity via antioxidant mechanisms. Our findings might raise
the possibility of potential therapeutic application of N. sativa extract and TQ for managing cerebral ischemic and neurodegenerative disorders. 相似文献
16.
M. E. Estrada-Zúñiga F. Cruz-Sosa M. Rodríguez-Monroy J. R. Verde-Calvo E. J. Vernon-Carter 《Plant Cell, Tissue and Organ Culture》2009,97(1):39-47
Plant tissue cultures represent a potential source for producing secondary metabolites. In this work, Buddleja cordata tissue cultures were established in order to produce phenylpropanoids (verbascoside, linarin and hydroxycinnamic acids),
as these metabolites are credited with therapeutic properties. Highest callus induction (76.4–84.3%) was obtained in five
treatments containing 2,4-Dichlorophenoxyacetic acid (2,4-d: 0.45–9.05 μM) with Kinetin (KIN: 2.32, 4.65 μM), whereas highest root induction (79.6%) corresponded to the α-Naphthaleneacetic
acid (9.05 μM) with KIN (2.32 μM) treatment. Verbascoside was the major phenylpropanoid produced in in vitro cultures (root,
white and green callus) [66.24–86.26 mg g−1 dry weight (DW)], while linarin and hydroxycinnamic acid production was low (0.95–3.01 mg g−1 DW). Verbascoside and linarin production were improved in cell suspension culture (116 mg g−1 DW and 8.12 mg g−1 DW, respectively). 相似文献
17.
Jiří Masojídek Jiří Kopecký Luca Giannelli Giuseppe Torzillo 《Journal of industrial microbiology & biotechnology》2011,38(2):307-317
This work aims to: (1) correlate photochemical activity and productivity, (2) characterize the flow pattern of culture layers
and (3) determine a range of biomass densities for high productivity of the freshwater microalga Chlorella spp., grown outdoors in thin-layer cascade units. Biomass density, irradiance inside culture, pigment content and productivity
were measured in the microalgae cultures. Chlorophyll-fluorescence quenching was monitored in situ (using saturation-pulse
method) to estimate photochemical activities. Photobiochemical activities and growth parameters were studied in cultures of
biomass density between 1 and 47 g L−1. Fluorescence measurements showed that diluted cultures (1–2 g DW L−1) experienced significant photostress due to inhibition of electron transport in the PSII complex. The highest photochemical
activities were achieved in cultures of 6.5–12.5 g DW L−1, which gave a maximum daylight productivity of up to 55 g dry biomass m−2 day−1. A midday depression of maximum PSII photochemical yield (F
v/F
m) of 20–30% compared with morning values in these cultures proved to be compatible with well-performing cultures. Lower or
higher depression of F
v/F
m indicated low-light acclimated or photoinhibited cultures, respectively. A hydrodynamic model of the culture demonstrated
highly turbulent flow allowing rapid light/dark cycles (with frequency of 0.5 s−1) which possibly match the turnover of the photosynthetic apparatus. These results are important from a biotechnological point
of view for optimisation of growth of outdoor microalgae mass cultures under various climatic conditions. 相似文献
18.
Hélio V. Nobre-Júnior Ricardo A. Oliveira Flavio D. Maia Marcelle A. S. Nogueira Manoel Odorico de Moraes Mary Anne M. Bandeira Geanne M. Andrade Glauce S. B. Viana 《Neurochemical research》2009,34(6):1066-1075
In the present work, we showed that a chalcone-enriched fraction (CEF) isolated from the stem bark of a Brazilian medicinal
plant, Myracrodruon
urundeuva, presents neuroprotective actions on 6-hydroxydopamine (6-OHDA)-induced neuronal cell death, in rat mesencephalic cells.
In the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium] assay, which is an index of cell viability, CEF (1–100 μg/ml)
reversed in a concentration-dependent manner the 6-OHDA-induced cell death. While cells exposed to 6-OHDA (40 μM) showed an
increased concentration of thiobarbituric acid reactive substances (TBARS), the pretreatment with CEF (10–100 μg/ml) significantly
decreased the 6-OHDA-induced TBARS formation, indicative of a neuroprotection against lipoperoxidation. Furthermore, the drastic
increase of nitrite levels induced by 6-OHDA, indicative of nitric oxide formation and free radicals production, was prevented
by CEF. Double staining with acridine orange/ethidium bromide showed that cultures exposed to 6-OHDA (40 and 200 μM) presented
an increase of apoptotic and necrotic cell numbers in a concentration-dependent manner. CEF (100 μg/ml) protected cells from
apoptosis and necrosis and increased number of cells presenting a normal morphology. The immunohistochemical analysis for
tyrosine hydroxylase (TH) positive neurons indicated that 6-OHDA (40 and 200 μM) caused a concentration-dependent loss of
TH+ and TH− neurons. CEF protected both cells types from 6-OHDA-induced cell death. All together, our results demonstrated
neuroprotective effects of chalcones, which are able to reduce oxidative stress and apoptotic injury caused by 6-OHDA. Our
findings suggest that chalcones could provide benefits, along with other therapies, in neurodegenerative injuries, such as
Parkinson’s disease. 相似文献
19.
Peter M. Kilonzo Argyrios Margaritis Maurice A. Bergougnou 《Journal of industrial microbiology & biotechnology》2010,37(8):773-783
The recombinant Saccharomyces cerevisiae strain C468/pGAC9 has an unstable hybrid plasmid pGAC9, which directs production of glucoamylase. A fibrous cotton material
with a good adsorption capability for recombinant S. cerevisiae cells was used as the immobilization matrix in an internal loop airlift-driven fibrous bed bioreactor (ILALFBB) system. With
batch cultures in the ILALFBB, the fraction of plasmid-carrying cells was 72% after more than 2 days cultivation, which was
two times higher than that in the conventional free-cell culture. Correspondingly, a high activity of glucoamylase (GA; 113 U/l)
was achieved with a high productivity of 43 U/l/h. The ILALFBB system also maintained a high fraction of viable plasmid-carrying
of 74% for glucoamylase production during repeated-batch cultures, achieving a high glucoamylase activity of 140 U/l with
a productivity of 19–130 U/l/h in all 14 batches studied during 19.8 days. The stable and long-term glucoamylase production
from the ILALFBB was attributed to the effect of cell immobilization on plasmid stability. Plasmid-carrying cells were preferentially
retained in the fibrous matrix because of their ability to adhere to the fiber surface and to form cell aggregates higher
than those of plasmid-free cells. The repeated batch using immobilized cell of recombinant S. cerevisiae in the ALALFBB system thus provides a feasible method for stable, long-term and high-level production of glucoamylase. 相似文献
20.
Heidi Andrea Declercq Leo Isabelle De Ridder Maria Jozefa Cornelissen 《Cytotechnology》2005,49(1):39-50
Selection of appropriate cultures having an osteogenic potential is a necessity if cell/biomaterial interactions are studied
in long-term cultures. Osteoblastic cells derived from rat long bones or calvaria have the disadvantage of being in an advanced
differentiation stage which results in terminal differentiation within 21 days. In this regard, less differentiated periosteum-derived
osteoprogenitors could be more suitable.
Periosteum-derived cells were isolated from the tibiae of adult Wistar rats (n = 12). The osteogenic potential with regard to alkaline phosphatase activity, morphology, nodule formation and mineralization
was studied by culturing them in an osteogenic medium for up to 4 months.
Seventy-five percent of the cultures (n = 9) did not show any increase in alkaline phosphatase activity nor nodule formation during long-term culture for up to 4
months. Nevertheless, in 25% of the cultures, alkaline phosphatase activity started from negligible (<5 mM pNP/mg protein)
and increased towards approximately 50 mM pNP/mg protein. Three-dimensional nodule formation was observed at passages 3–5.
In further passages (P5–P7), nodule formation capacity decreased and a diffuse mineralization pattern was observed.
Suitable cultures with osteogenic capacity, can be selected at early passages based on the presence of cuboidal cells. These
cells have the advantage of retaining their osteogenic potential even after prolonged cultivation (6–7 passages) before final
differentiation occurs. Although periosteal cells are suitable for long term in vitro evaluation of biomaterials, the isolation and selection is time consuming. Hence, a more appropriate source to study cell/biomaterial
interactions should be more convenient. 相似文献