Co-reporter:Abiodun Emmanuel Adekunle;Feng Wang;Jianhua Hu
Bioprocess and Biosystems Engineering 2015 Volume 38( Issue 10) pp:1973-1981
Publication Date(Web):2015 October
DOI:10.1007/s00449-015-1438-z
Chitosan multiple addition strategy was developed to improve laccase production from Trametes versicolor cultures. The optimized multiple addition strategy was carried out by two-time addition of 0.1 g L−1 chitosan to a 2-day-old culture media, with 24-h interval between the treatments. Under these conditions, laccase activity of 644.9 U l−1 was achieved on the seventh day and laccase production was improved by 93.5 % higher than the control. Chitosan treatment increased reactive oxygen species generation and extracellular protein concentration in the treated mycelia. In contrast, the inducer inhibited the mycelia growth. The result of the quantitative reverse transcription polymerase chain reaction showed that the copy number of the laccase gene transcript increased by 16.7-fold in the treated mycelia relative to the control. This study provides insight into some of the intrinsic metabolic processes involved in the upregulation of laccase production in the presence of chitosan inducer in fungal culture.
Co-reporter:Shi-Kai Wang, Feng Wang, Yi-Ru Hu, Amanda R. Stiles, Chen Guo, and Chun-Zhao Liu
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 1) pp:109
Publication Date(Web):December 16, 2013
DOI:10.1021/am404764n
Magnetic flocculant was synthesized for the highly efficient recovery of microalgal cells. The highest flocculation was achieved using the magnetic flocculant synthesized with iron oxide and 0.1 mg/mL cationic polyacrylamide (CPAM). This resulted in a recovery efficiency of more than 95% within 10 min using a dosage of 25 mg/L for Botryococcus braunii and 120 mg/L for Chlorella ellipsoidea. For both species, the adsorption isotherm data fit the Freundlich model better than the Langmuir model, indicating that the adsorption process was a heterogeneous multilayer. The maximum adsorption capacity was 114.8 and 21.4 mg dry cells/mg-particles at pH 7 for B. braunii and C. ellipsoidea, respectively. The primary flocculation mechanism was bridging, which was assisted by the electrostatic interactions between the microalgal cells and the magnetic flocculant under acidic conditions. These results provide new opportunities and challenges for understanding and improving the harvesting of microalgae using magnetic separation.Keywords: Botryococcus braunii; cationic polyacrylamide; Chlorella ellipsoidea; magnetic flocculant; microalgae harvesting;
Co-reporter:Ying Liu;Chen Guo
Catalysis Letters 2014 Volume 144( Issue 9) pp:1552-1556
Publication Date(Web):2014 September
DOI:10.1007/s10562-014-1303-8
The resolution of (R,S)-2-octanol catalyzed by magnetite-immobilized Yarrowia lipolytica lipase in ionic liquids was investigated. The optimal activity and enantioselectivity of the lipase were obtained in a mixture of [EMIM]BF4 and [OMIM]BF4 (v/v = 5:5). Excellent reusability of the enzyme-ionic liquid system was observed in consecutive batch reactions.
Co-reporter:Feng Wang, An-Zhou Ma, Chen Guo, Guo-Qiang Zhuang, Chun-Zhao Liu
Ultrasonics Sonochemistry 2013 Volume 20(Issue 1) pp:118-124
Publication Date(Web):January 2013
DOI:10.1016/j.ultsonch.2012.05.003
An efficient intermittent ultrasonic treatment strategy was developed to improve laccase production from Trametes versicolor mycelia cultures. The optimized strategy consisted of exposing 2-day-old mycelia cultures to 5-min ultrasonic treatments for two times with a 12-h interval at the fixed ultrasonic power and frequency (120 W, 40 kHz). After 5 days of culture, this strategy produced the highest extracellular laccase activity of 588.9 U/L among all treatments tested which was 1.8-fold greater than the control without ultrasound treatment. The ultrasonic treatment resulted in a higher pellet porosity that facilitated the mass transfer of nutrients and metabolites from the pellets to the surrounding liquid. Furthermore, the ultrasonic treatment induced the expression of the laccase gene (lcc), which correlated with a sharp increase in both extracellular and intracellular laccase activity. This is the first study to find positive effects of ultrasound on gene expression in fungal cells. These results provide a basis for understanding the stimulation of metabolite production and process intensification by ultrasonic treatment in filamentous fungal culture.Highlights► An efficient ultrasonic treatment strategy was developed to improve laccase production. ► Ultrasonic treatment resulted in a high pellet porosity that facilitated mass transfer. ► Ultrasonic treatment enhanced laccase gene expression that improved laccase biosynthesis.
Co-reporter:Feng Wang;Chen Guo
Journal of Industrial Microbiology & Biotechnology 2013 Volume 40( Issue 1) pp:141-150
Publication Date(Web):2013 January
DOI:10.1007/s10295-012-1214-x
The mycelia of Trametes versicolor immobilized in alginate beads provided higher laccase production than that in pelleted form. An efficient ultrasonic treatment enhanced laccase production from the immobilized T. versicolor cultures. The optimized treatment process consisted of exposing 36-h-old bead cultures to 7-min ultrasonic treatments twice with a 12-h interval using a fixed ultrasonic power and frequency (120 W, 40 kHz). Using the intensification strategy with sonication, laccase production increased by more than 2.1-fold greater than the untreated control in both flasks and bubble column reactors. The enhancement of laccase production by ultrasonic treatment is related to the improved mass transfer of nutrients and product between the liquid medium and the gel matrix. These results provide a basis for the large-scale and highly-efficient production of laccase using sonobioreactors.
Co-reporter:Bin Guo;Amanda R. Stiles
In Vitro Cellular & Developmental Biology - Plant 2013 Volume 49( Issue 3) pp:320-325
Publication Date(Web):2013 June
DOI:10.1007/s11627-013-9497-9
Saussurea involucrata Kar. et Kir. is one of the most well-known Chinese medicinal plants, and it is utilized for a variety of medical conditions. Due to the overexploitation of this endangered species, it is crucial to develop methods for both conservation and propagation. To address this issue, we have developed and optimized a simple and effective vitrification process for the cryopreservation of S. involucrata callus tissue. The optimized method consisted of a 3-d incubation period on medium containing 0.3 M sucrose, transfer to a plant vitrification solution (PVS2) containing 30% (v/v) glycerol, 15% (v/v) ethylene glycol, 15% (v/v) dimethylsulfoxide, and 0.4 M sucrose first at 60% PVS2 for 40 min, then at 100% PVS2 for 60 min, followed by immediate immersion and storage in liquid nitrogen. To thaw the tissue, tissues were rewarmed at 40°C for 2 min. This method resulted in a survival rate of approximately 56% and a regrowth rate of approximately 40%. Survival and regrowth were significantly improved by the addition of a low-temperature preincubation step. Incubating the calli at 4°C for 12 d prior to initiating the optimized cryopreservation protocol increased the survival rate of the tissue to 75%, increased the regrowth rate to 60%, and more than doubled the number of regenerated shoots per explant. Following cryopreservation, greater than 90% of the regenerated shoots formed complete plantlets, and 81% of the regenerated plantlets survived and grew vigorously under greenhouse conditions.
Co-reporter:Qian Li, Chun-Zhao Liu
International Journal of Hydrogen Energy 2012 Volume 37(Issue 14) pp:10648-10654
Publication Date(Web):July 2012
DOI:10.1016/j.ijhydene.2012.04.115
A strategic method utilizing the co-culture of Clostridium thermocellum and Clostridium thermosaccharolyticum has been developed to improve hydrogen production via the thermophilic fermentation of cornstalk waste. The hydrogen yield in the co-culture fermentation process reached 68.2 mL/g-cornstalk which was 94.1% higher than that in the mono-culture. The hydrogen fermentation process was successfully scaled-up from 125 mL anaerobic bottles to an 8 L continuous stirred tank reactor, and the hydrogen production from cornstalk waste was significantly improved in the bioreactor system due to efficient mixing and mass transfer. The hydrogen yield in the bioreactor reached 74.9 mL/g-cornstalk which was 9.8% higher than that in the 125 mL anaerobic bottle. The present work indicates that the direct microbial conversion of lignocellulosic waste by co-culturing C. thermocellum and C. thermosaccharolyticum is a promising avenue for enhancing hydrogen production.Highlights► The synergistic co-culture process was developed to improve hydrogen production. ► The co-culture process was scaled-up from anaerobic bottle to stirred tank reactor. ► The direct bioconversion of cornstalk is a promising avenue for hydrogen production.
Co-reporter:Bin Guo;Amanda R. Stiles
In Vitro Cellular & Developmental Biology - Plant 2012 Volume 48( Issue 6) pp:609-612
Publication Date(Web):2012 December
DOI:10.1007/s11627-012-9468-6
An efficient protocol for the in vitro micrpropagation of Saussurea involucrata Kar. et Kir, an endangered Chinese medicinal plant, was developed. Shoot organogenesis was obtained following culture of leaf explants on Murashige and Skoog (MS) medium supplemented with thidiazuron (TDZ). After 28 d of culture, 15.6 ± 1.4 shoots were regenerated per leaf explant on MS medium containing 0.5 μM TDZ. After transfer of shoots to a medium containing 5.0 μM indole-3-acetic acid, approximately 80% of the regenerated shoots formed roots and whole plantlets. After transfer of rooted shoots to the greenhouse, 83% of the regenerated plantlets survived and grew vigorously. The regeneration protocol developed in this study provides a basis for germplasm conservation and for the production of plant material necessary to study the medicinally active components of S. involucrata.
Co-reporter:Feng Wang;Chen Guo;Tao Wei;Tian Zhang
Applied Biochemistry and Biotechnology 2012 Volume 168( Issue 2) pp:256-265
Publication Date(Web):2012 September
DOI:10.1007/s12010-012-9769-6
An efficient heat shock strategy has been developed to improve laccase production in submerged Trametes versicolor cultures. The optimized heat shock strategy consists of subjecting T. versicolor mycelial pellets to three heat shock treatments at 45 °C for 45 min, starting at culture day 0, with a 24-h interval between treatments. Laccase production increased by more than 1.6-fold relative to the control in both flasks and a 5-L bioreactor because the expression of the laccase gene was enhanced by heat shock induction. The present work demonstrates that heat shock induction is a promising method because it both improves fungal laccase production and has a good potential in industrial application.
Co-reporter:Yan Zhao;Wei Sun;Ying Wang;Praveen K. Saxena
Applied Biochemistry and Biotechnology 2012 Volume 166( Issue 6) pp:1480-1490
Publication Date(Web):2012 March
DOI:10.1007/s12010-012-9542-x
A temporary immersion bioreactor system was found to be suitable for mass shoot proliferation of Rhodiola crenulata. The shoot multiplication ratio and hyperhydration rate reached 46.8 and 35.4%, respectively, at a temporary immersion cycle of 3-min immersion every 300 min. Forced ventilation was employed in the temporary immersion bioreactor culture in order to decrease the hyperhydration rate, improve shoot quality and enhance the multiplication ratio. The highest multiplication ratio of 55.7 was obtained under a temporary immersion cycle of 3-min immersion every 180 min with the forced ventilation at an air flow rate of 40 l/h, and the hyperhydration rate was reduced to 26.1%. Forced ventilation also improved the subsequent elongation and rooting rate of these proliferated shoots, and the shoot cultures from the temporary immersion bioreactor formed complete plantlets when subcultured onto a rooting medium containing 5 μmol/l indole-3-acetic acid.
Co-reporter:Xi-Yu Cheng and Chun-Zhao Liu
Energy & Fuels 2011 Volume 25(Issue 4) pp:1714-1720
Publication Date(Web):March 22, 2011
DOI:10.1021/ef2000344
An efficient hydrogen production process via thermophilic fermentation of cornstalk was developed by Clostridium thermocellum 7072. The hydrogen fermentation process was successfully scaled from a 125 mL anaerobic bottle to a 100 L continuous stirred-tank reactor, and the hydrogen production from cornstalk was significantly improved in the bioreactor system because of good mixing and mass transfer. The hydrogen yield in the 100 L continuous stirred-tank reactor reached 61.4 mL/g of cornstalk, which was higher than that in the 125 mL anaerobic bottle. The present work indicated that direct microbial conversion of lignocellulosic waste via C. thermocellum was a promising avenue for biohydrogen production.
Co-reporter:Xi-Yu Cheng
Journal of Chemical Technology and Biotechnology 2010 Volume 85( Issue 1) pp:127-131
Publication Date(Web):
DOI:10.1002/jctb.2278
Abstract
BACKGROUND: Lignocellulosic wastes such as herbal-extraction process residues (HPR) are not easily utilized by microorganisms owing to their physical shielding of cellulose imparted by the non-digestible lignin. Therefore, there is a great interest to develop an efficient pretreatment technique to disrupt recalcitrant structures of lignocellulosic wastes and improve renewable energy production.
RESULTS: A microwave-assisted alkaline pretreatment (MAP) method has been developed for the enhancement of biogas production from HPR. The maximum cumulative biogas production reached 1477 mL when the HPR was hydrolyzed by MAP for 30 min with an alkali loading of 0.12 g-NaOH/g-HPR, where the maximum weight loss of HPR after biogas fermentation reached 72.1%.
CONCLUSION: The present work demonstrated that MAP is a promising method for improving bioconversion of lignocellulosic wastes to biogas. HPR pretreated by combining microwave irradiation and alkali resulted in releasing more soluble substances from HPR and increasing the accessibility of HPR for anaerobic biodigestion compared with traditional alkaline pretreatment (AP) and microwave-assisted water pretreatment (MWP). Copyright © 2009 Society of Chemical Industry
Co-reporter:Chun-zhao Liu, Xi-yu Cheng
International Journal of Hydrogen Energy 2010 Volume 35(Issue 17) pp:8945-8952
Publication Date(Web):September 2010
DOI:10.1016/j.ijhydene.2010.06.025
A microwave-assisted acid pretreatment (MAP) strategy has been developed to enhance hydrogen production via thermophilic fermentation of corn stover. Pretreatment of corn stover by combining microwave irradiation and acidification resulted in the increased release of soluble substances and made the corn stover more accessible to microorganisms when compared to thermal acid pretreatment (TAP). MAP showed obvious advantages in short duration and high efficiency of lignocellulosic hydrolysis. Analysis of the particle size and specific surface area of corn stover as well as observation of its cellular microstructure were used to elucidate the enhancement mechanism of the hydrolysis process by microwave assistance. The cumulative hydrogen volume reached 182.2 ml when corn stover was pretreated by MAP with 0.3 N H2SO4 for 45 min, and the corresponding hydrogen yield reached 1.53 mol H2/mol-glucose equivalents converted to organic end products. The present work demonstrates that MAP has potential to enhance the bioconversion efficiency of lignocellulosic waste to renewable biofuel.
Co-reporter:Bilal Haider Abbasi;Rui Liu;Praveen K. Saxena
Journal of Chemical Technology and Biotechnology 2009 Volume 84( Issue 11) pp:1697-1701
Publication Date(Web):
DOI:10.1002/jctb.2233
Abstract
BACKGROUND: Hairy root cultures of Echinacea offer great potential for the production of valuable cichoric acid, but scale-up of the culture in the bioreactor represents a big challenge. Therefore, there is great interest in developing a suitable bioreactor for hairy root culture of Echinacea and novel bioprocessing strategies for intensifying cichoric acid production.
RESULTS: Homogenous distribution of inoculum roots and high cichoric acid production were observed in a bioreactor modified by installing a mesh draught tube with an average pore size 700 µm, slightly larger than the hairy root, about 500 µm. Improved root growth and cichoric acid production were improved by increasing the aeration rate from 0.002 m3 h−1 to 0.012 m3 h−1. The hairy root cultures in the modified bioreactor exposed once to 6 min of ultrasound treatment at day 20 gave the highest biomass accumulation of 12.8 ± 0.3 g L−1, which resulted in the maximum cichoric acid production of 178.2 ± 4.9 mg L−1 at day 30.
CONCLUSION: The present work demonstrated the effectiveness of hairy root culture in a modified airlift bioreactor. The biomass distribution remained homogenous in the modified airlift bioreactor, and the cichoric acid production was improved owing to the even root growth at optimal air flow rate. An interesting finding of this investigation was that ultrasound stimulated root growth and cichoric acid production considerably in the modified airlift bioreactor. Copyright © 2009 Society of Chemical Industry
Co-reporter:Feng Wang and Chun-Zhao Liu
Energy & Fuels 2009 Volume 23(Issue 8) pp:4137-4142
Publication Date(Web):July 8, 2009
DOI:10.1021/ef900317s
Two strategies for refining sweet sorghum to ethanol and feedstuff were investigated in the inner Mongolia region, a typical pastoral area in China. Strategy 1 is to conduct submerged ethanol fermentation from sweet sorghum juice followed by feedstuff production from bagasse by a mixed culture of Aspergillus niger and Geotrichum candidum. Strategy 2 is to conduct solid-state ethanol fermentation from dried sweet sorghum stalk followed by feedstuff production from residue after ethanol distillation by a mixed culture of A. niger and G. candidum. The economic analysis indicated that strategy 2 performed a higher net present value than strategy 1 and the ethanol price had the greatest impact on the net present value.
Co-reporter:Chun-Zhao Liu and Xi-Yu Cheng
Energy & Fuels 2009 Volume 23(Issue 12) pp:6152-6155
Publication Date(Web):October 1, 2009
DOI:10.1021/ef900607f
A microwave-assisted acid hydrolysis pretreatment (MAHP) method has been developed for the enhancement of biogas production from herbal-extraction process residue (HPR). HPR pretreated by combining microwave irradiation and acid resulted in releasing more soluble substances from HPR and making more accessibility of HPR for anaerobic biodigestion in comparison to traditional acid hydrolysis pretreatment (AHP) and microwave-assisted water hydrolysis pretreatment (MWHP). The maximum cumulative biogas production reached 1272 mL after 19 days when the HPR was hydrolyzed by MAHP for 30 min at a H2SO4 concentration of 1.2% (w/w). The present work demonstrated that MAHP was a promising way for improving bioconversion of lignocellulosic wastes to renewable energy.
Co-reporter:Liangrong Yang, Chen Guo, Shu Chen, Feng Wang, Jing Wang, Zhentao An, Chunzhao Liu and Huizhou Liu
Industrial & Engineering Chemistry Research 2009 Volume 48(Issue 2) pp:944
Publication Date(Web):December 9, 2008
DOI:10.1021/ie800969q
A pH-sensitive magnetic ion exchanger was synthesized by binding carboxymethylated chitosan (CMCH) covalently on the surface of Fe3O4 nanoparticles. The diameter for magnetic particles observed at 25 °C was 15 nm. The ion exchanger was superparamagnetic with a saturation magnetization of 64.21 emu/g and an isoelectric point (pI) of 5.75. In a model system, the laccase adsorption capacity reached equilibrium within 15 min (pH 5). The adsorption process followed the Langmuir adsorption isotherm, and the maximum equilibrium adsorption capacity was calculated to be 198.81 mg/g. The laccase can be completely desorbed at pH 8. About 97% laccase can be effectively desorbed from the surface of particles within 15 min. Moreover, the specific activity of the laccase remained constant during the adsorption and desorption process. Finally, the pH-sensitive magnetic ion exchanger was used for separation of laccase directly from culture supernatant, and nearly pure laccase was isolated by a single step with an activity recovery rate of 63%.
Co-reporter:Feng Wang;Xue-Rong Xiong
In Vitro Cellular & Developmental Biology - Plant 2009 Volume 45( Issue 3) pp:342-349
Publication Date(Web):2009 June
DOI:10.1007/s11627-009-9209-7
With rapid economic development, energy consumption in China has tripled in the past 20 yr, exceeding 2.4 billion tons of standard coal in 2006. The search for new green energy as substitutes for the nonrenewable energy resources has become an urgent task. China has a variety of climates and is rich in potential biofuel plant species. Corn and cassava are used as the main raw materials for bioethanol production in China. At the end of 2005, bioethanol productivity had increased to 1.02 million tons produced by four companies, and bioethanol-blended petrol accounted for 20% of the total petrol consumption in China. According to the Mid- and Long-term Development Plan for Renewable Energy, the consumption of biodiesel in China will reach 0.2 million tons in 2010 and 2.0 million tons in 2020. This review is intended to provide an introduction to the distribution and development of biofuel crops and biofuel industry in China.
Co-reporter:Bin Zhang, Ruiyuan Yang, Chun-Zhao Liu
Separation and Purification Technology 2008 Volume 62(Issue 2) pp:480-483
Publication Date(Web):1 September 2008
DOI:10.1016/j.seppur.2008.02.013
An efficient microwave-assisted extraction (MAE) technique has been developed to recover chlorogenic acid from flower buds of Lonicera japonica Thunb. The yield of chlorogenic acid rapidly reached 6.14% within 5 min under the optimal MAE conditions, i.e. 50% ethanol as extraction solvent, 1:10 (w/v) of the solid/liquid ratio and 60 °C of extraction temperature. The MAE showed obvious advantages in terms of short duration and high efficiency to recover chlorogenic acid from raw plant materials in comparison with conventional heat-reflux extraction. The mechanism of the enhanced extraction by microwave assistance was discussed by observing cell destruction of plant material after MAE treatment by scanning electron microscopy. The results showed that the plant materials were significantly destroyed due to the cell rupture after MAE treatment.
Co-reporter:Bin Zhang, Ruiyuan Yang, Yan Zhao, Chun-Zhao Liu
Journal of Chromatography B 2008 Volume 867(Issue 2) pp:253-258
Publication Date(Web):15 May 2008
DOI:10.1016/j.jchromb.2008.04.016
Chlorogenic acid, one of the most bioactive compounds rich in the Chinese medicinal herb honeysuckle, is a natural antioxidant and serves as anti-inflammatory, anti-tumor, anti-mutagenic and anti-carcinogenic agent. An efficient preparative separation process of chlorogenic acid from honeysuckle crude extracts has been developed in the present study. HPD-850 resin offers the best adsorption capacity, and adsorption and desorption ratios for chlorogenic acid among the nine macroporous resins tested, and its adsorption rate at 25 °C fit best to the Langmuir isotherm. The adsorption capacity of HPD-850 resin was found to depend strongly on the pH value of the initial adsorption solution. The dynamic adsorption and desorption experiments have been carried out on a HPD-850 resin packed column to optimize the separation process of chlorogenic acid from honeysuckle crude extracts. After one run treatment with HPD-850 resin, the chlorogenic acid content in the final product was increased 4.46-fold from 11.2% to 50.0%, with a recovery yield of 87.9%. The preparative separation of chlorogenic acid can be easily and efficiently achieved via adsorption and desorption on HPD-850 resin, and the method developed will provide a potential approach for large-scale separation and purification of chlorogenic acid for its wide pharmaceutical use.
Co-reporter:Chun-Zhao Liu;Min Gao;Bin Guo
Plant Cell Reports 2008 Volume 27( Issue 1) pp:39-45
Publication Date(Web):2008 January
DOI:10.1007/s00299-007-0466-9
An efficient micropropagation system for Erigeron breviscapus (vant.) Hand. Mazz., an important medicinal plant for heart disease, has been developed. Shoot organogenesis occurred from E. breviscapus leaf explants inoculated on a medium supplemented with a combination of plant growth regulators. On average, 17 shoots per leaf explant were produced after 30 days when they were cultured on MS basal salts and vitamin medium containing 5 μM 6-benzylaminopurine (BAP) and 5 μM 1-naphthaleneacetic acid (NAA). All the regenerated shoots formed complete plantlets on a medium containing 2.5–10 μM indole-3-butyric acid (IBA) within 30 days, and 80.2% of the regenerated plantlets survived and grew vigorously in field conditions. Based on the variation in common peaks and the produced amount of the most important bioactive component, scutellarin, a high performance liquid chromatography (HPLC) fingerprinting system was developed for quality control of these micropropagated plants. Chemical constituents in E. breviscapus micropropagated plants varied during plant development from regeneration to maturation, the latter of which showed the most similar phytochemical profile in comparison with mother plants. The regeneration protocol and HPLC fingerprint analysis developed here provided a new approach to quality control of micropropagated plants producing secondary metabolites with significant implications for germplasm conservation.
Co-reporter:Chun-Zhao Liu;Xi-Yu Cheng
Plant Cell Reports 2008 Volume 27( Issue 2) pp:357-362
Publication Date(Web):2008 February
DOI:10.1007/s00299-007-0443-3
The effect of osmotic stress on cell growth and phenylethanoid glycosides (PeGs) biosynthesis was investigated in cell suspension cultures of Cistanche deserticola Y. C. Ma, a desert medicinal plant grown in west region of China. Various initial sucrose concentrations significantly affected cell growth and PeGs biosynthesis in the suspension cultures, and the highest dry weight and PeGs accumulation reached 15.9 g l−1-DW and 20.7 mg g−1-DW respectively at the initial osmotic stress of 300 mOsm kg−1 where the sucrose concentration was 175.3 mM. Stoichiometric analysis with different combinations of sucrose and non-metabolic sugar (mannitol) or non-sugar osmotic agents (PEG and NaCl) revealed that osmotic stress itself was an important factor for enhancing PeGs biosynthesis in cell suspension cultures of C. deserticola. The maximum PeGs contents of 26.9 and 23.8 mg g−1-DW were obtained after 21 days at the combinations of 87.6 mM sucrose with 164.7 mM mannitol (303 mOsm kg−1) or 20 mM PEG respectively, which was higher than that of C. deserticola cell cultures grown under an initial sucrose concentration of 175.3 mM after 30 days. The stimulated PeGs accumulation in the cell suspension cultures was correlated to the increase of phenylalanine ammonium lyase (PAL) activity induced by osmotic stress.
Co-reporter:Min Gao, Wei Huang, Moytri RoyChowdhury, Chunzhao Liu
Analytica Chimica Acta 2007 Volume 591(Issue 2) pp:161-166
Publication Date(Web):22 May 2007
DOI:10.1016/j.aca.2007.04.004
An efficient microwave-assisted extraction (MAE) technique has been developed to extract scutellarin from Erigeron breviscapus for rapid determination by high-performance liquid chromatography (HPLC). The maximum yield of scutellarin reached 1.02% in 40 min under the optimal MAE conditions with 80 °C of extraction temperature and 1:10 (w/v) of the solid/liquid ratio. The MAE showed obvious advantages in terms of short duration and high efficiency to extract scutellarin in comparison with heat-flux extraction. The mechanism of the enhanced extraction by microwave assistance was discussed by detecting particle size and specific surface area of plant materials and observing cell destruction of plant material by light microscopy and scanning electron microscopy. The results showed that the plant materials were significantly destroyed due to the cell rupture after MAE treatment. Afterward, the method validation for HPLC-UV analysis was developed. Calibration range was 0.1–100 μg mL−1 for scutellarin, and correlation coefficient R was 0.9993. Limit of detection was less than 0.01 μg mL−1. The intra- and inter-day relative standard deviation (R.S.D.) of scutellarin detection ranged from 1.58% to 2.96% and from 3.32% to 4.19%, respectively. The recovery of the method for scutellarin ranged from 96.7% to 101.9%.
Co-reporter:Chun-Zhao Liu, Hua-Ying Zhou, Yan Zhao
Analytica Chimica Acta 2007 Volume 581(Issue 2) pp:298-302
Publication Date(Web):9 January 2007
DOI:10.1016/j.aca.2006.08.038
Artemisinin isolated from the aerial parts of Artemisia annua L., is a promising and potent antimalarial drug, which meets the dual challenge posed by drug-resistant parasites and rapid progression of malarial illness. The aim of the current study was to develop a reliable and fast analytical procedure for the determination of artemisinin in A. annua using high performance liquid chromatography (HPLC) with evaporative light scattering detection (ELSD) in couple with microwave-assisted extraction (MAE) as an efficient sample preparation technique. The HPLC conditions were Agilent C18 column using water:acetonitrile (40:60 v/v) mixture as mobile phase at a flow rate of 1 mL min−1. ELSD conditions were optimized at nebulizer-gas flow rate of 2.0 L min−1 and drift tube temperature of 70 °C under the impactor off-mode, and the gain was set at 2. Afterwards, method validation system for HPLC–ELSD analysis was developed. Calibration range was 0.2–1.0 mg mL−1 and correlation coefficient r was above 0.9990. Precision experiments showed relative standard deviation (R.S.D.) of retention time was less than 0.5% and R.S.D. of peak area was less than 1.30%. Inter-day and intra-day variabilities showed that R.S.D. was ranged from 1.01% to 4.66%. Limit of detection was less than 40 μg mL−1 and limit of quantification was less than 100 μg mL−1. Accuracy validation showed that average recovery was between 98.23% and 104.97%. The developed analytical procedure was successfully applied to determine the contents of artemisinin in the different parts of A. annua plants.
Co-reporter:Chun-Zhao Liu, Hua-Ying Zhou, Qiong Yan
Analytica Chimica Acta 2007 Volume 582(Issue 1) pp:61-68
Publication Date(Web):16 January 2007
DOI:10.1016/j.aca.2006.08.057
High-performance liquid chromatographic method (HPLC) with evaporative light scattering detection (ELSD) coupled with microwave-assisted extraction (MAE) as an efficient sample preparation technique has been developed for fingerprint analysis of Dioscorea nipponica. The samples were separated with an Agilent C8 column using water (A) and acetonitrile (B) under gradient conditions (0–10 min, linear gradient 20–40% B; 10–12 min, linear gradient 40–42% B; 12–25 min, isocratic 42% B) as the mobile phase at a flow rate of 1 mL min−1 within 22 min. The ELSD conditions were optimized at nebulizer-gas flow rate 2.7 L min−1 and drift tube temperature 90 °C. Precision experiments showed relative standard deviation (R.S.D.) of peak area and retention time were better than 2.5%; inter-day and intra-day variabilities showed that R.S.D. was ranged from 0.78% to 4.74%. Limit of detection was less than 50 μg mL−1 and limit of quantification was less than 80 μg mL−1. Accuracy validation showed that average recovery was between 97.39% and 104.07%. The method was validated to achieve the satisfactory precision and recovery. Relative retention time and relative peak area were used to identify the common peaks for fingerprint analysis. There are nine common peaks in the fingerprint. The quality of seven batches of D. nipponica samples was evaluated to be qualified or unqualified by the parameters “difference” and “total difference” of common peaks. Furthermore, the contents of important medicinal compounds (dioscin, prodioscin and gracillin) in different batches of D. nipponica samples were determined simultaneously using the developed HPLC-ELSD method. The results indicated variation of the herb quality which might be related to different producing area, growing condition, climate, harvest time, drug processing and so on. The developed analytical procedure was proved to be a reliable and rapid method for the quality control of D. nipponica.
Co-reporter:Min Gao, Wei Huang, Chun-Zhao Liu
Journal of Chromatography B 2007 Volume 858(1–2) pp:22-26
Publication Date(Web):15 October 2007
DOI:10.1016/j.jchromb.2007.07.046
Scutellarin, a flavone glycoside, popularly used in the treatment of heart disease, has been efficiently separated using macroporous resins from crude extracts of Chinese medicinal plant Erigeron breviscapus (vant.) Hand. Mazz. HPD-800 resin offered the best adsorption and desorption capacity for scutellarin among the eight macroporous resins tested, and its adsorption data at 25 °C fit best to the Langmuir isotherm. The dynamic adsorption and desorption experiments have been carried out on a HPD-800 resin packed column to optimize the separation process of scutellarin from the crude extracts of E. breviscapus. After one run treatment with HPD-800 resin, the scutellarin content in the product was increased 15.69-fold from 2.61% to 40.96% with a recovery yield of 95.01%. The preparative separation process via adsorption–desorption method developed in this study provides a new approach for scale-up separation and purification of scutellarin for its wide pharmaceutical use.
Co-reporter:Bin Guo;Yong-Gang Liu;Qiong Yan
Plant Growth Regulation 2007 Volume 52( Issue 3) pp:259-263
Publication Date(Web):2007 July
DOI:10.1007/s10725-007-9192-0
Cell growth, flavonoids biosynthesis and L-phenylalanine ammonia-lyase (PAL) activity were studied in callus cultures of Saussurea medusa Maxim. under different types of spectral radiance. After 21 days, red light significantly improved the callus growth, but inhibited the biosynthesis of flavonoids in callus cultures. However, blue light was found to enhance the biosynthesis of flavonoids, although callus growth under this spectrum was comparable with that under white and other coloured spectra, such as green and yellow. The accumulation of flavonoids in callus cultures was related to the PAL activity, which was found to be stimulated by the spectral composition of irradiation.
Co-reporter:Bin Guo;Min Gao
Plant Cell Reports 2007 Volume 26( Issue 3) pp:261-265
Publication Date(Web):2007 March
DOI:10.1007/s00299-006-0230-6
An efficient micropropagation system for Saussurea involucrata Kar. et Kir., an endangered Chinese medicinal plant, has been developed. Shoot organogenesis occurred from S. involucrata leaf explants inoculated on medium with appropriate supplements of plant growth regulators. 66.0% of shoot regeneration frequency and 5.2 shoots per leaf explant were achieved when cultured on a medium containing 10 μM 6-benzylaminopurine (BAP) and 2.5 μM 1-naphthaleneacetic acid (NAA). Shoot organogenesis was improved further when the leaf explants were pre-incubated at low temperature, and 80.6% of shoot regeneration frequency was recorded with 9.3 shoots per leaf explant at 4°C by 5-day pretreatment period. Up to 87.0% of the regenerated shoots formed complete plantlets on a medium containing 2.5 μM indole-3-acetic acid (IAA) within 28 days, and 85.2% of the regenerated plantlets survived and grew vigorously in greenhouse condition. The phytochemical profile of the micropropagated plants was similar to that of wild plants. The regeneration protocol developed in this study provides a basis for germplasm conservation and for further investigation of medicinally active constituents of the elite medicinal plant.
Co-reporter:Bilal Haider Abbasi;Praveen K. Saxena
In Vitro Cellular & Developmental Biology - Plant 2007 Volume 43( Issue 6) pp:481-492
Publication Date(Web):2007 December
DOI:10.1007/s11627-007-9057-2
Echinacea, better known as purple coneflower, has received a global attention because of its increasing medicinal value. There is enormous potential for the discovery of new medicinal compounds in this species and an immediate need for techniques to facilitate the production of high quality, chemically consistent plant material for drug development and clinical trials. In vitro tissue culture of Echinacea can play a vital role in the development of novel germplasm, rapid multiplication, and genetic modifications for an enhanced phytochemical production. Recent establishment of liquid culture techniques, large-scale bioreactors, and Agrobacterium-mediated transformation are changing the production parameters of the Echinacea species. This review provides an overview of the recent developments in in vitro technologies and challenges that remain in the Echinacea biotechnology.
Co-reporter:Hua-Ying Zhou, Chun-Zhao Liu
Journal of Chromatography A 2006 Volume 1129(Issue 1) pp:135-139
Publication Date(Web):29 September 2006
DOI:10.1016/j.chroma.2006.07.083
Solanesol is the starting material for many high-value biochemicals, including co-enzyme Q10 and Vitamin K analogues. In the present study, a microwave-assisted extraction (MAE) technique has been developed for the fast extraction of solanesol from tobacco leaves. Compared to heat-reflux extraction, MAE reduced extraction time and obtained higher percentage extracted of solanesol. The effect of microwave on cell destruction of plant material was observed by scanning electron microscopy (SEM). The microwave-assisted extraction efficiency was further improved by adding NaOH into the extraction solvent, and the maximum percentage extracted of solanesol reached 0.91% (weight solanesol/weight tobacco) in 40 min at an optimum NaOH concentration of 0.05 M. The developed MAE integrated with saponification process provided an efficient method for solanesol recovery from tobacco leaf materials, and it also alleviated emulsification in the following separation and purification procedure as well.
Co-reporter:Min Gao, Ming Gu, Chun-zhao Liu
Journal of Chromatography B 2006 Volume 838(Issue 2) pp:139-143
Publication Date(Web):11 July 2006
DOI:10.1016/j.jchromb.2006.04.030
Scutellarin, a flavone glycoside, popularly applied for the treatment of cardiopathy, has been purified in two-step purification by high-speed counter-current chromatography (HSCCC) from Erigeron breviscapus (vant.) Hand. Mazz. (Deng-zhan-hua in Chinese), a well-known traditional Chinese medicinal plant for heart disease. Two solvent systems, n-hexane–ethyl acetate–methanol–acetic acid–water (1:6:1.5:1:4, v/v/v/v/v) and ethyl acetate–n-butanol–acetonitrile–0.1% HCl (5:2:5:10, v/v/v/v) were used for the two-step purification. The purity of the collected fraction of scutellarin was 95.6%. This study supplies a new alternative method for purification of scutellarin.
Co-reporter:Hua-Ying Zhou, Chun-Zhao Liu
Journal of Chromatography B 2006 Volume 835(1–2) pp:119-122
Publication Date(Web):1 May 2006
DOI:10.1016/j.jchromb.2006.02.055
Solanesol is the starting material for many high-value biochemicals, including coenzyme Q10 and Vitamin-K analogues. The aim of the current study was to develop a reliable and fast analytical procedure for the determination of solanesol in tobacco using high-performance liquid chromatography (HPLC) with evaporative light scattering detection (ELSD) coupled with microwave-assisted extraction (MAE) as an efficient sample preparation technique. The HPLC conditions were Agilent C18 column using acetonitrile–isopropanol (60:40, v/v) as mobile phase at a flow rate of 1 ml/min. ELSD conditions were optimized at nebulizer-gas flow rate of 1.5 l/min and drift tube temperature of 65 °C. The method was validated to achieve the satisfactory precision and recovery, and the calibration range was 0.1–1.5 mg/ml. The developed analytical procedure was successfully applied to determine solanesol content in tobacco samples from different growing regions in China.
Co-reporter:Ying Liu, Chen Guo, Chun-Zhao Liu
Journal of Molecular Catalysis B: Enzymatic (March 2014) Volume 101() pp:23-27
Publication Date(Web):1 March 2014
DOI:10.1016/j.molcatb.2013.12.011
•Solvent structure affects resolution performance of (R, S)-2-octanol by lipase.•Acyclic linear solvent resulted in efficient enantioselectivity and enzymatic activity.•Mixture of acetone and carbon tetrachloride was developed for enhancing enzymatic resolution.In order to find a suitable reaction system for the enzymatic resolution of (R, S)-2-octanol, the effects of the molecular structure of the solvent on the enantioselectivity (E) and enzymatic activity of Yarrowia lipolytica lipase (YLL) immobilized onto magnetic nanoparticles were systematically analyzed. Both the E and enzymatic activity of the reaction in an acyclic, structurally linear solvent were higher than those in the corresponding branched chain solvent or cyclic solvent. In a mixed solvent system with acetone and carbon tetrachloride (v/v = 3:7), the immobilized YLL exhibited high enantioselectivity, activity, and reusability. The thermodynamic analysis showed that the enantiomer discrimination was enthalpy-driven at all temperatures tested. These results present new opportunities and challenges for understanding and intensifying the enzymatic resolution process of (R, S)-2-octanol by designing suitable solvent system.Download full-size image
Co-reporter:Shan-shan He, Chun-zhao Liu, Praveen K. Saxena
Scientia Horticulturae (5 June 2007) Volume 113(Issue 1) pp:82-86
Publication Date(Web):5 June 2007
DOI:10.1016/j.scienta.2007.01.014
Goldenseal (Hydrastis canadensis L.) is an endangered medicinal plant used to treat sore eyes and mouths, cold and flu and also as a dye. The objective of this study was to develop an efficient in vitro propagation protocol for goldenseal. Significantly more shoots (26 shoots per leaf explants) were induced on a medium containing 2.5 μM thidiazuron (TDZ) and 5.0 μM 1-naphthaleneacetic acid (NAA) than any other treatment. Sub-culturing regenerated shoots on a medium with 5.0 μM 6-benzylaminopurine (BA) induced the maximum rate of shoot multiplication. Growth of the regenerated shoots in a temporary immersion bioreactor resulted in significant increases in biomass, shoot height and shoot multiplication. The regenerated shoots from the temporary immersion bioreactor formed roots when transferred onto a medium with 1.0–2.0 μM indole-3-butyric acid (IBA). Regenerated whole plantlets were acclimatized and maintained in standard greenhouse conditions for further growth. The regeneration protocol developed in this study provides a basis for germplasm conservation and for further investigation of this rare, medicinally important species.
Co-reporter:Feng Wang, Chen Guo, Hui-Zhou Liu, Chun-Zhao Liu
Journal of Molecular Catalysis B: Enzymatic (3 September 2007) Volume 48(Issues 1–2) pp:1-7
Publication Date(Web):3 September 2007
DOI:10.1016/j.molcatb.2007.05.003
Magnetic Cu2+-chelated particles, prepared by cerium initiated graft polymerization of tentacle-type polymer chains with iminodiacetic acid (IDA) as chelating ligand, were employed for glucoamylase immobilization. The particles had an obvious high adsorption capacity of glucoamylase with a great activity recovery of 84.0% after immobilization. The immobilized glucoamylase exhibited improved stability in reaction conditions over a wide pH region (pH 3.5–6.0) and a broad temperature range (45–75 °C). The value of the Michaelis constant (Km) of the immobilized glucoamylase (1.77 mg/ml) was higher than that of the free one (1.07 mg/ml), whereas the maximum velocity (Vmax) was lower for the adsorbed glucoamylase. Storage stability and temperature endurance of the immobilized glucoamylase were found to increase greatly, and the immobilized glucoamylase retained 75.7% of its initial activity after 30 successive batch reactions. The magnetic Cu2+-chelated particles also exhibited excellent reusability, indicating the advantage of the magnetic metal-chelated particles in biocatalytic applications.
Co-reporter:Rui Liu, Wei Li, Li-Yang Sun, Chun-Zhao Liu
Biochemical Engineering Journal (15 January 2012) Volume 60() pp:62-66
Publication Date(Web):15 January 2012
DOI:10.1016/j.bej.2011.10.001
An efficient ultrasound-stimulation strategy was developed for improving the hairy root growth and caffeic acid derivatives (CADs) biosynthesis in the hairy root cultures of Echinacea purpurea L. The 15-day-old hairy roots stimulated every 5 days by ultrasound for 6 min produced the highest amount of CADs after 30 days of culture among all ultrasound treatment experiments. The obvious increase of CADs production in E. purpurea hairy roots stimulated by ultrasound was related to the increase of both rolB-regulated endogenous indole-3-acetic acid biosynthesis and phenylalanine ammonium lyase (PAL) activity. These results provided a basis for understanding of improving growth and secondary metabolism in the process of hairy root culture stimulated by ultrasound.Highlights► An efficient ultrasound-intensified strategy has been developed for improving CADs biosynthesis in E. purpurea hairy roots. ► The ultrasound-stimulated root growth was related to the increase of rolB gene expression for endogenous IAA biosynthesis. ► The ultrasound-stimulated CADs accumulation in the hairy roots was due to increasing phenylalanine ammonium lyase activity. ► The results presented new opportunities for understanding the hairy root culture process by ultrasound stimulation.
