Biotransformation of Gastrodin by Cell Suspension Cultures of Catharanthus roseus

应用长春花 (Catharanthusroseus (L .)G .Don)悬浮细胞培养体系对天麻素进行了生物转化反应研究。经过8d培养形成一个转化产物 ,应用光谱方法鉴定转化产物的结构为对羟基苯甲醇 ,为天麻素水解后形成的甙元。

Productions of Taxol and Related Taxanes by Cell Suspension Cultures of Taxus yunnanensis

A high taxol yield cell line of Taxus yunnanensis Cheng et L. K. Fu keeps a high taxol_producing level after successive subcultures for more than eight years. In this study, eight taxanes were isolated from the suspension cell cultures of this cell line. Based on NMR and MS analyses, and comparison with literature data and standards, their structures were determined to be 2α,5α,10β_triacetoxy_14β_propionyloxy_4(20),11_taxadiene (1), 2α,5α,10β_triacetoxy_14β_(2′_methyl)_butyryloxy_4(20),11_taxadiene (2), 2α,5α,10β_14β_tetra_acetoxy_4 (20),11_taxadiene (3, taxuyunnanine C), 2α,5α,10β_triacetoxy_14β_(2′_methyl_3′_hydroxy)_butyryloxy_4(20),11_taxadiene (4, yunnanxane) and its 3′_epimer (5), baccatin Ⅳ (6), baccatin Ⅲ (7) and taxol (8), respectively. Among those compounds, 3, 5, 6 and 7 were reported to be isolated from the suspension cell cultures of T. yunnanensis for the first time. TLC and HPLC analyses indicated that the chemical constituents of the culture solution were similar to those of cultured cells. Moreover, the highest taxol content of this cell line reached 0.3% and the cell line could be applied for a large_scale culture.

Study on the Browning in Cell Suspension Culture of Taxus cuspidata

[Objective] This study aimed to investigate the browning of T. cuspidata cells in suspension culture and provide the guidance for the cell suspension culture of T. cuspidata. [Method] T. cuspidata callus was used as experimental materials, to explore the effect of different medium, N/P ratio, pH, shaking speed, illumination time and light intensity and other factors on browning of T. cuspidata cells in suspension culture. [Result] Non-browning callus was transferred to 2MB5 medium （pH 7.0） for illumination culture at 22℃ under light intensity of 1 500 lx with shaking speed of 90 r/min for 24 h. Results showed that the cell browning was significantly inhibited. [Conclusion] This study laid the foundation for cell suspension culture of T. cuspidata and had important significance to the large-scale industrial production of paclitaxel.

MORPHOLOGICAL MODEL FOR RHEOLOGICAL PROPERTIES OF PLANT CELL SUSPENSION CULTURE SYSTEM

This paper puts forward a physical and mathematical model for the rheological properties of a plant cell suspension culture system.The model can explain why the system is pseudoplastic satisfactorily,thus the rheological properties of the system as the effect of the flow behavior index on plant cell concentration are interpreted correctly and the mechanism of the rheological properties of the system is further understood.Therefore the model can be applied in the technological design and optimum conditions of the system and the reformation,evaluation and scale up of reactors.

Selective 3-OH Isomerization of Resibufogenin by Cell Suspension Cultures of Ginkgo biloba

Aim To modify the structure of resibufogenin by using Ginkgo bilobasuspension. Methods Young leaves of Ginkgo biloba were differentiated into callus in MS medium withonly 2,4-D as plant growth regulator. The callus was then transferred aseptically to liquid MSmedium exoge-nously supplemented with appropriate concentration of 6-BA, NAA and 2,4-D to establishsuspension cell culture system. Resibufogenin was administered into the well-grown cell cultures andincubated for 4 d. The products dissolved in the liquid phase of the cultures were extracted andpurified by silica gel column chromatography gradiently eluted with petroleum ether and acetonesystem. Results One transformed product was obtained in 40% yield after 4 d incubation, which wasidentified as 3-epi-resibufogenin on the basis of FAB MS, ~1H NMR and ^(13)C NMR spectroscopicanalysis and corresponding data reported in literature. Conclusion G. biloba suspension cultures canbe used as an enzyme system to biotransform resibufogenin, an animal-originated bufadienolide, into3-epi-resibufogenin.

Biomass accumulation of Panax vietnamensis in cell suspension cultures varies with addition of plant growth regulators and organic additives

Objective: To evaluate the impact of plant growth regulators including kinetin(KN),benzyl adenine and naphthalene acetic acid, yeast extract and casein hydrolyzate on biomass accumulation of Vietnamese ginseng Panax vietnamensis(P. vietnamensis) in cell suspension culture.Methods: Cell suspension cultures were established from friable calluses derived from leaves and petioles of 3-year-old in-vitro P. vietnamensis plants. The cell suspension cultures were grown in Murashige and Skoog basal media supplemented with various concentrations of KN, benzyl adenine, naphthalene acetic acid, and yeast extract and casein hydrolyzate.Results: All tested factors generated an increase in the cell biomass of P. vietnamensis in suspension culture, but the impact of each varies depended on the factor type, concentration, and incubation period. Addition of 2.0 mg/L KN resulted in the largest biomass increase after 24 d,(57.0 ± 0.9) and(3.1 ± 0.1) mg/m L fresh and dry weight, respectively,whereas addition of benzyl adenine or naphthalene acetic acid produced optimum levels of Panax cell biomass at 1.0 and 1.5 mg/L, respectively. Addition of the elicitor yeast extract led to a 1.4–2.4 fold increase in biomass of P. vietnamensis, while addition of casein hydrolyzate enhanced biomass accumulation 1.8–2.6 fold.Conclusions: The addition of each factor causes significant changes in biomass accumulation of P. vietnamensis. The largest biomass accumulation is from cultures grown in MS media containing 2.0 mg/L KN for 24 d. The outcome of the present study provides new insights into the optimal suspension culture conditions for studies on the in vitro cell biomass production of P. vietnamensis.

Research on Electric Impedance Spectroscopy of Living Cell Suspensions by a Chip with Microelectrodes

A microfabricated electrical impedance spectroscopy (EIS) chip with microelectrodes was developed.The substrate and the electrodes of the chip were made of glass and gold,respectively.The experimental results demonstrated that the EIS-chip could distinguish different solutions (physiological saline,culture medium,living cell suspension etc.) by scanning from 10Hz to 45kHz.A 6-element circuit model was used for fitting the real part and the imaginary part admittance curves of the living cell suspension.An actual circuit was also built and tested to verify the 6-element circuit model proposed.The micro-EIS chip has several advantages including the use of small sample volumes,high resolution and ease of operation.It shows good application prospects in the areas of cellular electrophysioiogy,drug screening and bio-sensors etc.

Establishment of cell suspension line of Populus tomentosa Carr

Leaves of fine Populus tomentosa genotype TC152 were used as explants to establish cell suspension lines. The effects of plant growth regulators on callus induction and establishment of cell suspension lines were studied. The callus induction rate was the highest on a MS solid medium supplemented with 1.0 mg·L^-1 2,4-D. A cell suspension line could be obtained by inoculating calli which were not subcultured into a MS liquid medium supplemented with 1.5 mg·L^-1 2,4-D. The best subculture medium was MS ＋ 0.8 mg＇L-1 2,4-D ＋ 30 g·L^-1 sucrose with a subculture cycle of seven days.

Somatic Embryogenesis from Cell Suspension Cultures of Aspen Clone

Suspension cultures initiated from callus derived from petiole explants of aspen hybrid （Populus tremuloides×P. tremula） produced somatic embryos. Callus was induced on a MS medium supplemented with 5mg·L^-1 2,4-D and 0.05mg·L^-1 zeatin under light conditions. Embryogenic calli were obtained when a subsequent subculture of calli was suspended in the same basal medium with 10mg·L^-1 2,4-D. The highest number of globular embryos were induced from embryogenic calli by cell suspension culture in a MS liquid medium supplemented with 10mg·L^-1 2,4-D. Genotype and 2,4-D concentration were vital to the induction of embryogenic calli producing competent cells. Embryogenic calli for each genotype were heterogeneous. Green calli with gel-like consistency could yield more competent cells than light yellow embryogenic calli. However, some globular embryos broke into slices and some developed abnormally after one month of culture under the same or other hormonal conditions.

Study on Cell Suspension Culture of Floribunda Rose

Friable callus was induced when immature seeds of floribunda rose were inoculated on MS medium supplemented with 2,4-D 3.0 mg.L^-1. When transfered onto subculture media, friable callus developed into embryogenic callus, which was used to establish cell suspension lines. Cell suspensions had to be subcultured at a interval of 4-5 days at the first several culture cycles. The best subculturing cycle for the stable cell suspensions was 8-10 days. The best inoculum quantity was 1 mL PCV（Packed Cell Volume） per 40 mL culture fluid.

Studies on Cell Suspension Culture of Ricinus communis L.

Ricinus communis L. is a new copper hyperaccumulator growing on Tonglushan copper mine in Hubei Province, China. This study aimed to establish a suspension cell line of R. communis L. with stable and rapid growth for further screening of heavy metal-resistant R. communis L. cells and breeding of hyperaccu- mulators. In this study, cell suspension culture conditions were optimized by using orthogonal experimental design with previously induced R. communis L. embyre- genic calluses as experimental materials, to establish the suspension cell line of R. communis L. Under the optimal conditions, growth curves of suspension cells and changes in pH of culture liquid were determined. The results showed that the optimal culture conditions for R. conmmnis L. suspension cell line were ： MS ＋ O. 5 rag/I, 6-BA ＋ O. 2 mg/L NAA ＋ 50 mg/L sucrose ＋ 350 mg/L casein hydrolysate as basic medium, with callus inoculation amount of 2.5 g/50 ml, dark culture at （26 ±2） ℃ with shaking at 110 r/min. Under these conditions, increment of fresh weight and dry weight ofR. commun/s L. suspension cells reached the maximum of 4.56 g/（50 ml 14 d） and 0.49 g/（50 ml 16 d）, respectively. Growth curves of R. communis L. suspension cells were basically in ＂S＂ shape. Each culture cycle lasted 16 d, and the rapid growth stage was from the 6th d to the 14th d. In a culture cycle, pH of the culture liquid declined first and then increased to the maximum and stabilized gradually.

Cell replacement with stem cell-derived retinal ganglion cells from different protocols

Glaucoma,characterized by a degenerative loss of retinal ganglion cells,is the second leading cause of blindness worldwide.There is currently no cure for vision loss in glaucoma because retinal ganglion cells do not regenerate and are not replaced after injury.Human stem cell-derived retinal ganglion cell transplant is a potential therapeutic strategy for retinal ganglion cell degenerative diseases.In this review,we first discuss a 2D protocol for retinal ganglion cell differentiation from human stem cell culture,including a rapid protocol that can generate retinal ganglion cells in less than two weeks and focus on their transplantation outcomes.Next,we discuss using 3D retinal organoids for retinal ganglion cell transplantation,comparing cell suspensions and clusters.This review provides insight into current knowledge on human stem cell-derived retinal ganglion cell differentiation and transplantation,with an impact on the field of regenerative medicine and especially retinal ganglion cell degenerative diseases such as glaucoma and other optic neuropathies.

Analytical model for power dissipation in cell membranes in suspensions exposed to electric fields

Due to interaction among cells, it is too complex to build an exactanalytical model for the power dissipation within the cell membrane in suspensions exposed toexternal fields. An approximate equivalence method is proposed to resolve this problem. Based on theeffective medium theory, the transmembrane voltage on cells in suspensions was investigated by theequivalence principle. Then the electric field in the cell membrane was determined. Finally,analytical solutions for the power dissipation within the cell membrane in suspensions exposed toexternal fields were derived according to the Joule principle. The equations show that theconductive power dissipation is predominant within the cell membrane in suspensions exposed todirect current or lower frequencies, and dielectric power dissipation prevails at high frequenciesexceeding the relaxation frequency of the exposed membrane.

Chemical Constituents of the Suspension Cell Cultures of Maytenus hookeri

Suspension cell cultures of Maytenus hookeri Loos. (Celastraceae) in SH media were established from the calli induced from the leaves and young steins of M. hookeri on MS media with the supplement of 2 mg/L 2,4-D and 0.1 mg/L KIN (kinetin). Ethyl acetate extract of the cultures showed inhibitory activities against Penicillium avellaneum UC-4376 which was sensitive to maytansinoids. Exhaustive isolation of natural products from a large scale of suspension cell cultures did not yield maytansine instead of affording nine compounds including one novel triterpenoid, named 2, 3-diacetoxyl maytenusone (1), and eight known ones including squalene (2), beta-sitosterol (3), 2', 3', 4-triacetyl-sitoindoside I (4), salaspermic acid (5), maytenonic acid (6), 2alpha-hydroxy-maytenonic acid (7), 6, 11,12-trihydroxy-8, 11, 13-abietrien-7-one (8) and 11, 12-dihydroxy-8, 11, 13-abietatrien-7-one (9) elucidated on the basis of 1D and 2D NMR data. The H-1-NMR and C-13-NMR assignments were made for 1, 5, 6 and 7, while the C-13-NMR assignments for 5 and 6 were revised. The chemical results suggested that the suspension cell cultures of M. hookeri did not produce maytansinoids under the reported experiment conditions.

Isolation of Protoplast and Ion Channel Recording in Plasma Membrane of Suspension Cells of Populus euphratica

The authors used suspension cells of Populus euphratica to isolate protoplast in the present study. Protoplasts were successfully obtained after 4 hours incubation in enzyme solution containing 1 0% cellulase “onozuka” R\|10, 0\^01% pectolyase Y\|23,0\^15% macerozyme R\|10 and 0\^1% hemicellulase at 25℃. Outward and inward single channels in plasma membrane were observed using cell\|attached recording of patch\|clamp technique. In this study, single channel records showed that more than one species of channel were obtained. These attempts in protoplast isolation and ion channel recording offers the opportunity to characterize cellular mechanisms of salt tolerance in tree species.

Effects of feeding tyrosine and phenylalanine on the accumulation of phenylethanoid glycosides to Cistanche deserticola cell suspension culture

AIM: To investigate the effects of feeding phenylalanine(Phe) and tyrosine(Tyr) on the accumulation of total phenolic compounds and four phenylethanoid glycosides(PeGs) to a cell suspension culture of the parasitic plant Cistanche deserticola. METHOD: A cell suspension culture of C. deserticola was established and precursors of different concentrations were fed. In each group, the cell was sampled at the 24th day after inoculation. The content of total phenolic compounds and four PeGs compounds were determined using the Folin-Ciocalteu method and an HPLC method, respectively. RESULTS: In the Phe fed cells, the maximum PeGs yield was achieved when Phe was fed at 1.5 mmol·L-1 and the yield reached 1.13 times the control cell concentration. In the Tyr fed cells, the maximum yield of PeGs was 1.60 times of control when 0.75 mmol·L-1 Tyr was fed to the cells. Furthermore, it was found that the salidroside yield was 4.01 times of control group when 5 mmol·L-1 Tyr was fed. CONCLUSION: Tyr is a better precursor for PeGs accumulation compared with Phe, and the rate limiting enzymes might be involved in the Tyr branch.

Acaricidal activities of whole cell suspension,cell-free supernatant,and crude cell extract of Xenorhabdus stokiae against mushroom mite (Luciaphorus sp.)

Xenorhabdus bacterium has been used as a biological control agent against Luciaphorus sp., a mushroom mite endemic in Thailand. To develop an effective formulation ofXenorhabdus stokiae, treatments using different parts of X. stokiae isolate PB09 culture, including whole cell suspension, cell-free supernatant, and crude cell extract, were performed. The results show that different parts ofX. stokiae isolate PB09 culture could induce variable effects on mite mortality and fecundity. Application with cell-free supernatant of X. stokiae culture resulted in both the highest mite mortality rate [（89.00＋3.60）%] and the lowest mite fecundity [（41.33_＋23.69） eggs/gravid female]. Whole cell suspen- sion of X. stokiae isolate PB09 culture was found to be slightly less effective than its cell-free supernatant, suggesting that X. stokiae was more likely to release its metabolites with acaricidal activities to the surrounding culture media. Crude cell extract of X. stokiae was not effective against mites. Cell-free supematant of X. stokiae isolate PB09 was the most effective biological control agent and it could be conveniently used in future formulations instead of live bacteria.

Influences of Plant Growth Regulators， Basal Media and Carbohydrate Levels on Cell Suspension Culture of Panax ginseng

A cell suspension culture of Panax ginseng which may be continuously subcultured has been established. Embryogenic callus derived from clutured young leaves was used to initiate the culture.Plant growth regulators, basal medium formula and carbohydrate levels were examined to determine their various effects on suspension culture cell growth and development. The best selection of plant growth regulator, hasal medium and carbohydrate level is 2 mg / L 2,4-D: 0.5 mg / L KT,MS and 3% sucrose respectively.

Studies on Parameters Affecting Embryogenesis of Protoplasts Isolated from Suspension of Embryogenic Cells in Loblolly Pine

Protoplasts of embryogenic suspension cells of loblolly pine (Pinus taeda L).were isolated at exponential growth stage.Influences of various concentrations of basal medium,levels of BA,and concentrations of inositol on the differentiation of embryonal suspensor mass (ESM),early stage somatic embryos (ESE) ,and lae stage somatic embryos (LSE) were investigated .A study of the effect of various concentrations of LP basal medium sowed that the optimal basal medium concentration of ESM,ESE,and LSE differentiation was 1.25 LP medium.The effects of various levels of BA and inositol showed that the optimal concentrations of BA for the formation of ESM,ESE and LSE were 4 mg/L ,2mg/L and 1mg/L,respectively ,and the optimal concentrations of inositol for the ESM ,ESE and LSM formation were 400mg/L,800mg/L and 1,200mg/L,respectively.

Cell Suspension Culture of Neem Tree

The establishment of suspension culture system for neem (Azadirachta indica A. Juss) cells and the suspension culture condition was studied. It shows that the neem cell suspension culture system was best in B5 liquid medium, 2.0~4.0mg/L NAA with direct spill method. Based on the integrated analysis of cell biomass, Azadirachtin content and productivity, the optimum culture conditions were B5 liquid medium, 2.0-4.0 mg/L NAA, 3% sucrose at 25 ℃. The optimum rotating speed of the shaker and broth content d...