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1.
Ammonium to nitrate ratios of 0:30, 5:25, 10:20, 15:15, 20:10, 25:5, and 30:0 mM were tested to determine the optimal NH(4)(+) :NO(3)(-) ratio for improving biomass and bioactive compound production in Eleutherococcus koreanum Nakai adventitious roots using 3-L bulb-type bubble bioreactors. A high ammonium nitrogen ratio had a negative effect on root growth, and the highest fresh and dry weights were obtained when NH(4)(+):NO(3)(-) ratios were 5:25 and 10:20 (mM) after 5 weeks of culture. Although the total production of eleutherosides B and E was slightly higher at the 10:20 ratio than at the 5:25 ratio (NH(4)(+):NO(3)(-)), we proposed that the optimal NH(4)(+):NO(3)(-) ratio was 5:25 mM. This ratio achieved both the highest total production of five target bioactive compounds (eleutherosides B and E, chlorogenic acid, total phenolics, and flavonoids) and the highest root biomass. Furthermore, increasing NH(4)(+):NO(3)(-) ratios to 10:20 decreased pH in the medium, interrupted the absorption of essential minerals from the culture medium, and resulted in low biomass and increased relative oxidative stress levels, which were evaluated by determining 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity. Therefore, nitrate rather than ammonium nitrogen was more essential not for only biomass production but also for bioactive compound production in E. koreanum adventitious root cultures. The optimal nitrogen source ratio produced 5.63 g L(-1) of biomass and 24.41 mg of the five total bioactive compounds per gram of biomass (dry weight basis). The development of such in vitro culture technology will benefit the pilot-scale production of E. koreanum-based bioactive compounds for commercialization.  相似文献   

2.
Present investigation involves hairy root cultivation of Azadirachta indica in a modified stirred tank reactor under optimized culture conditions for maximum volumetric productivity of azadirachtin. The selected hairy root line (Az-35) was induced via Agrobacterium rhizogenes LBA 920-mediated transformation of A. indica leaf explants (Coimbatore variety, India). Liquid culture of the hairy roots was developed in a modified Murashige and Skoog medium (MM2). To further enhance the productivity of azadirachtin, selected growth regulators (1.0?mg/l IAA and 0.025?mg/l GA3), permeabilizing agent (0.5?% v/v DNBP), a biotic elicitor (1?% v/v Curvularia (culture filtrate)) and an indirectly linked biosynthetic precursor (50?mg/l cholesterol) were added in the growth medium on 15th day of the hairy root cultivation period in shake flask. Highest azadirachtin production (113?mg/l) was obtained on 25th day of the growth cycle with a biomass of 21?g/l DW. Further, batch cultivation of hairy roots was carried out in a novel liquid-phase bioreactor configuration (modified stirred tank reactor with polyurethane foam as root support) to investigate the possible scale-up of the established A. indica hairy root culture. A biomass production of 15.2?g/l with azadirachtin accumulation in the hairy roots of 6.4?mg/g (97.28?mg/l) could be achieved after 25?days of the batch cultivation period, which was ~27 and ~14?% less biomass and azadirachtin concentration obtained respectively, in shake flasks. An overall volumetric productivity of 3.89?mg/(l?day) of azadirachtin was obtained in the bioreactor.  相似文献   

3.
We investigated different concentrations of auxins (1AA, IBA, NAA), the strength of the MS medium, sucrose and ammonium/nitrate contents, initial medium pH, and inoculum size to determine their effects on biomass increase and the accumulation of total phenols and flavonoids in adventitious roots ofEchinacea angustifolia. These roots were cultured under darkness in shake flasks for 4 weeks. IBA proved the best auxin for inducing root proliferation. Root growth was inhibited when the initial pH was maintained below 5.0 or above 6.0. Nitrate, rather than ammonium, was more necessary for root growth and phenolics accumulations. Overall, biomass increased and total phenol and flavonoid contents were maximized under the following conditions: half-strength MS medium supplemented with 2 mg L-1 IBA, 5% (w/v) sucrose, 5:25 (mM) ammonium/nitrate ratio, pH adjusted to 6.0 before autoclaving, and an inoculum size of 10 g L-1 FW. These results indicate that the type ofin vitro environment strongly affects growth and the accumulation of phenolics from adventitious root cultures ofE. angustifolia. Such optimization is beneficial to large-scale production of biomass and secondary metabolites in that species.  相似文献   

4.
Summary Callus culture ofDioscorea deltoidea produced diosgenin and sterols during stationary phase. Ammonium nitrate (420 mg Nitrogen/l) as sole nitrogen source supported better growth than a combination of ammonium nitrate and potassium nitrate (totally equivalent to 840 mg Nitrogen/l). The production of diosgenin increased under low phosphate concentration (100 mg/l) whereas high phosphate concentration (240 mg/l) promoted growth. Micronutrients, when used at 1 1/2 strength, enhanced growth and diosgenin production. Depletion of nitrogen increased the diosgenin synthesis by a factor of 2. Adoption of a two stage culture method enhanced the diosgenin production in cultured cells by eight-fold.  相似文献   

5.
Medium nutrients such as calcium, phosphorus, nitrogen and nitrate to ammonium ratio have significant influence on the growth, biosynthetic and biochemical characteristics of polysaccharides produced by Silene vulgaris (M.) G. cell culture. Cell growth and production of polysaccharides was limited by an absence of any of these components in the medium. Optimal growth of the callus and production of arabinogalactan were achieved at 1.5-4.5 microM calcium while the optimal production of pectin named silenan was observed at 3.0-4.5 microM. The phosphate contents in the medium in the range of 0.63-3.75 microM were favorable for callus growth. Production of silenan was maximal at 1.25-3.75 microM phosphate. Optimal growth of the callus was achieved at 30-90 microM nitrogen. Maximal production of silenan was observed at 60 microM nitrogen while the optimal production of arabinogalactan was at 90 microM nitrogen (at ratio of NH(4)(+):NO(3)(-) as 1:2). A presence both of nitrate and ammonium is needed for the silenan biosynthesis (the NH(4)(+):NO(3)(-) ratio as 1:1 and 1:2). Yields and volumetric production of arabinogalactan were maximal at deletion of ammonium from the nutrient medium (ratio 0:1). Absence of calcium or nitrogen in the medium leads to a decrease of the galacturonic acid residues in silenan. The galactose residues contents in arabinogalactan were decreased in the absence of nitrogen and calcium in the medium.  相似文献   

6.
4-Androstene-3,17-dione (AD) and 1,4-androstadiene-3,17-dione (ADD) are the main precursors in the production of steroidal drugs from phytosterols. To carry out the bioconversion, different inoculation strategies have been proposed. We compared the use of whole fermented broth and of free resting cells of two mutant strains of Mycobacterium sp. (DSMZ2966 and DSMZ2967) in shake flasks. Also the effect of the nitrogen source (ammonium sulfate, ammonium chloride and ammonium nitrate) and the sterol to biomass ratio at high substrate concentrations (19.2 g/l and 48.1 g/l) was evaluated. We found that the bioconversion with free resting cells (cell pellets) is more efficient than that with whole fermented broth, increasing both AD and ADD production. The use of ammonium nitrate in the culture medium and low substrate to biomass ratios (close to 1.0) increased the production yield. We also found that the bioconversion can be run at high substrate concentration under non-sterile conditions.  相似文献   

7.
The effect of major medium ingredients (sugar, nitrogen source and phosphate) in Podophyllum hexandrum suspension cultures was investigated in order to increase the production of podophyllotoxin, the raw material in the synthesis of anticancer drugs. Amongst B5, Eriksson, MS, Nitsch, Street and White's medium, MS medium resulted in high growth and podophyllotoxin accumulation. The optimum level of nitrogen was found to be 60 mM, with a combination of ammonium salts and nitrate in the ratio of 1:2. The highest level of podophyllotoxin was obtained at 60 g glucose/l and at 1.25 mM phosphate after 30 days. Statistical design was adopted to determine the optimum levels of the parameters for cell growth and podophyllotoxin production.  相似文献   

8.
To date enormous attempts have been devoted to improve Taxol production exploiting various methodologies from bioprocess engineering to biotechnological and synthetic approaches. We have developed a 2-stage suspension cell culture of Taxus baccata L. using modified B5 medium in order to improve cell growth as well as productivity. After callus induction and cell line selection, B5 medium was supplemented with vanadyl sulfate (0.1 mg/l), silver nitrate (0.3 mg/l) and cobalt chloride (0.25 mg/l) at the first day of stage I culture to maximize cell growth. This medium was further supplemented with sucrose (1%) and ammonium citrate (50 mg/l) on day 10 and sucrose (1%) and phenylalanine (0.1 mM) on day 20 (i.e., biomass growth medium). At stage II (day 25), two different concentrations of several elicitors such as methyl jasmonate (10 or 20 mg/l), salicylic acid (50 or 100 mg/l) and fungal elicitor (25 or 50 mg/l) were added to the biomass growth medium with the aim of improving cellular productivity. For morphological analysis, microscopic inspection was carried out during cultivation. Cell-associated and extracellular amount of Taxol were detected and measured using HPLC methodology. At stage I, overall Taxol amount of biomass growth medium was 13.75 mg/l (i.e., 5.6-fold higher than that of untreated B5 control). At stage II, treated cells with methyl jasmonate (10 mg/l), salicylic acid (100 mg/l) and fungal elicitor (25 mg/l) produced the highest amount of Taxol (39.5 mg/l), which is 16-fold higher than that of untreated B5 control (2.45 mg/l). Microscopic analyses of Taxus cells in suspension cultures showed various positional auto-fluorescence showing direct correlation with Taxol production. Our studies revealed that intervallic supplementation of B5 medium with combination of biomass growth factors at stage I and mixture of elicitors at stage II could significantly increase Taxol production. Thus, we suggest that the exploitation of this methodology may improve the production of Taxol since demands for Taxol pharmaceuticals are increasingly growing and resource paucities have limited its direct harvesting from Taxus trees.  相似文献   

9.
The effects of nitrate, ammonium, and urea as nitrogen sources on the heterotrophic growth of Chlorella protothecoides were investigated using flask cultures. No appreciable inhibitory effect on the algal growth was observed over a nitrogen concentration range of 0.85-1.7 g l(-)(1). In contrast, differences in specific growth rate and biomass production were found among the cultures with the various nitrogen compounds. The influence of different nitrogen sources at a concentration equivalent to 1.7 g l(-)(1) nitrogen on the heterotrophic production of biomass and lutein by C. protothecoides was investigated using the culture medium containing 40 g l(-)(1) glucose as the sole carbon and energy source in fermentors. The maximum biomass concentrations in the three cultures with nitrate, ammonium, and urea were 18.4, 18.9, and 19.6 g l(-)(1) dry cells, respectively. The maximum lutein yields in these cultures were between 68.42 and 83.81 mg l(-)(1). The highest yields of both biomass and lutein were achieved in the culture with urea. It was therefore concluded that urea was the best nitrogen source for the production of biomass and lutein. Based on the experimental results, a group of kinetic models describing cell growth, lutein production, and glucose and nitrogen consumption were proposed and a satisfactory fit was found between the experimental results and predicted values. Dynamic analysis of models demonstrated that enhancing initial nitrogen concentration in fermentor cultures, which correspondingly enhances cell growth and lutein formation, may shorten the fermentation cycle by 25-46%.  相似文献   

10.
The effect of a revised Linsmaier-Skoog (LS) medium on betacyanin production was investigated in suspension cultures of table beet (Beta vulgaris L.). The effects of a high iron concentration and low concentration of zinc on betacyanin production were not cumulative. The composition of the new revised medium for high betacyanin production was established by reducing the concentration of inorganic nitrogen (30 mM), modifying the ratio of ammonium to nitrate (1:14), reducing the concentration of zinc (0.0003 mM), and removing copper and cobalt. The revised LS medium enabled the maximum betacyanin yield of 550 mg/l to be obtained from a 14-day culture. This medium promoted the betacyanin production in three types of cell line differing in the betacyanin productivity. The betacyanin productivity (40 mg/l x day) was higher than that quoted in any other previous reports.  相似文献   

11.
Extensive spreading of liquid manure onto agricultural fields causes eutrophication of ground and surface water and also pollution of the atmosphere due to the high ammonium nitrogen content. A poly(gamma-glutamic acid) (PGA)-producing strain of Bacillus licheniformis was isolated in this study and investigated for its ability to reduce the ammonium nitrogen by converting ammonium into biomass and PGA as depot forms of nitrogen. In batch cultivations swine manure and an optimized mineral salts medium were used for PGA production. For example the cultivation of B. licheniformis strain S2 in liquid manure, which was modified by adding of 18 g citrate and 80 g glycerol l(-1) and exhibited a carbon to nitrogen ratio of 15.5:1, led to severe reduction of the ammonium content from 2.83 to 0.1 g x l(-1) and to the production of 0.16 g PGA and 7.5 g cell dry mass l(-1) within 410 h. Approximately 28% (w/w) of the total nitrogen was converted into cellular biomass, whereas 0.1% (w/w) was used for the production of PGA. In addition, approximately 33% (w/v) of the original ammonium was lost by stripping.  相似文献   

12.
Studies on the biotransformation of phosphogypsum (a waste product formed in the course of the production of phosphorous fertilizers) with the use of sulfate reducing bacteria (SRB) demonstrated that it is a good source of sulfates and biogenic elements for these bacteria, though the addition of organic carbon and nitrogen is necessary. The aim of this study was to investigate the form of nitrogen and C:N ratio in the medium on the growth of SRB community in cultures containing phosphogypsum. Batch community cultures of sulfate reducing bacteria were maintained in medium with phosphogypsum (5.0 g/l), different concentrations of sodium lactate (1.6 - 9.4 g/l) and different forms (NH4CI, CO(NH2)2, KNO3) and concentrations (0 - 250 mg/l) of nitrogen. The growth of SRB was studied in the C:N ratio of from 2:1 to 300:1. It was found that: 1 - the best source of nitrogen for SRB is urea, followed by ammonium, the worst were nitrates; 2 - the bacteria were also able to grow in medium without nitrogen but their activity was then by approximately 15% lower than in optimal growth conditions; 3 - in medium with KNO3 inhibition of sulfate reduction by approx. 50% was observed; 4 - the highest reduction of nitrates (removal of nitrate) in media with phosphogypsum and nitrates was at limiting concentrations of sodium lactate. This is probably caused by the selection under these conditions (low concentration of hydrogen sulfide) of denitrifying bacteria or sulfate reducing bacteria capable of using nitrates as an electron acceptor.  相似文献   

13.
A cell suspension culture of table beet (Beta vulgaris L.) was established for efficient betacyanin production from violet callus induced from the hypocotyls of aseptic seedlings. This suspension culture produced large amounts of betacyanins. The betacyanin content increased with increasing cell growth during the log phase. Reducing the total nitrogen concentration (30 mM) and modifying the ratio of ammonium to nitrate (1:14) resulted in an increased betacyanin content. Supplementation of Fe2+ to the LS medium also promoted betacyanin production. The maximal betacyanin yield was achieved with a 2 mM Fe2+ concentration. Combining these conditions, we established a revised LS medium to improve betacyanin productivity (250 mg/l for a 14-day culture).  相似文献   

14.
Azadirachtin, a well-known biopesticide, is a secondary metabolite extracted from the seeds of Azadirachta indica. In the present study, azadirachtin was produced in hairy roots of A. indica, generated by Agrobacterium rhizogenes-mediated transformation of leaf explants. Liquid cultures of A. indica hairy roots were developed with a liquid-to-flask volume ratio of 0.15. The kinetics of growth and azadirachtin production were established in a basal plant growth medium containing MS medium major and minor salts, Gamborg’s medium vitamins, and 30 g l−1 sucrose. The highest azadirachtin accumulation in the hairy roots (up to 3.3 mg g−1) and azadirachtin production (∼44 mg l−1) was obtained on Day 25 of the growth cycle, with a biomass production of 13.3 g l−1 dry weight. To enhance the production of azadirachtin, a Plackett–Burman experimental design protocol was used to identify key medium nutrients and concentrations to support high root biomass production and azadirachtin accumulation in hairy roots. The optimal nutrients and concentrations were as follows: 40 g l−1 sucrose, 0.19 g l−1 potassium dihydrogen phosphate, 3.1 g l−1 potassium nitrate, and 0.41 g l−1 magnesium sulfate. Concentrations were determined by a central composite design protocol and verified in shake-flask cultivation. The optimized medium composition yielded a root biomass production of 14.2 g l−1 and azadirachtin accumulation of 5.2 mg g−1, which was equivalent to an overall azadirachtin production of 73.84 mg l−1, 68% more than that obtained under non-optimized conditions.  相似文献   

15.
The increasing demand of diosgenin for high‐revenue synthesis of steroid hormones by the pharmaceutical industries has driven researchers to look for other alternatives. Solasodine which was reported to be present in Solanum mammosum is known to be a potential source. The present study highlighted that added methyl jasmonate, cholesterol and l ‐arginine into the modified liquid full‐strength Murashige and Skoog (MS) medium (with ammonium to nitrate ratio 10.3 mM: 39.4 mM, and 4% (w/v) sucrose) could influence the solasodine production in the hairy roots of S. mammosum. The findings showed that both hairy root line‐ATCC31798 and line‐A4 (which were separately induced by Agrobacterium rhizogenes strain ATCC31798 and A4) acquired solasodine productivity of 4.5 mg/g dry weight roots with average dry biomass of 190 mg after 32 days culture, when using 50 mg fresh weight roots as initial inoculum size, with 100 mM cholesterol, 1000 μM l ‐arginine and 300 μM methyl jasmonate added simultaneously into the culture medium on day 20 of culture. The amount of solasodine obtained was five times higher than those without both the elicitor and precursor treatment. The improved solasodine production with a high‐biomass growth could reduce the production cost of steroid synthesis in the long run.  相似文献   

16.
Summary Lactic acid was produced by Rhizopus arrhizus using waste potato starch as the substrate. The aim of this study was to identify the role of nitrogen sources and their impact on the formation of lactic acid and associated byproducts. Ammonium sulphate, ammonium nitrate, urea, yeast extract and peptone were assessed in conjunction with various ratios of carbon to nitrogen (C:N). Fermentation media with a low C:N ratio enhanced the production of lactic acid, biomass and ethanol, while a high C:N ratio favoured the production of fumaric acid. Ammonium nitrate appeared to be the most suitable nitrogen source for achieving a high and stable lactic acid yield, and minimizing the production of byproducts such as biomass and ethanol, while urea proved to be the least favourable nitrogen source. Yeast extract and peptone appeared to improve fungal cell growth. The kinetics data revealed that a high concentration of ammonium nitrate enhanced the lactic acid productivity. The maximum lactic acid concentration of 36.4 g/l, representing a yield of 91%, was obtained with addition of 0.909 g/l ammonium nitrate in 32 h.  相似文献   

17.
Two lines of the red and pale yellow cell suspension cultures, prepared fromPrunus x yedoensis Matsum. callus induced by Murashige and Skoog's (1962) basal medium supplemented with 2, 4-dichlorophenoxyacetic acid (2, 4-D, 1.0 mg/l), kinetin (0.1 mg/l) and sucrose (30 g/l), were maintained on Schenk and Hildebrandt medium as modified by Mitchell and Gildow (1975). The red cell suspension culture produced cyanidin 3-monoglucoside, 5, 4′-dihydroxy-7-methoxyisoflavone 4′-glucoside (prunetrin), isoquercitrin, catechin, epicatechin, and procyanidin B-1, B-2, B-3 and B-4, while the pale yellow cells produced only a small amount of catechin and epicatechin as main flavonoids. These flavonoid compounds found in the red cell culture were present also in maturePrunus leaves. Maximum growth and maximum amount of total phenol and proanthocyanidin (procyanidins) were obtained with 0.3 mg/l of both 2,4-D and kinetin. Maximum concentration of anthocyanin was also obtained with 0.3 mg/l 2, 4-D regardless of kinetin concentration. Accumulation of proanthocyanidin was markedly stimulated by low concentrations of phosphate, which reduced growth by about half, and also by high concentrations of inorganic nitrogen. Production of both anthocyanin and proanthocyanidin was reduced by lowered nitrogen levels. Cell growth and production of all phenolics were inhibited when ammonium ion replaced nitrate in the medium.  相似文献   

18.
一株高效解磷真菌新菌株的筛选鉴定及解磷特性   总被引:2,自引:0,他引:2  
从辽宁省辽中县多年耕种的日光温室番茄根际土壤中筛选出一株解磷真菌,通过菌落形态特征和ITS rDNA序列对比,鉴定该菌株为草酸青霉菌的一株新菌株,将其命名为PSF1.该菌株能利用葡萄糖、蔗糖、乳糖、半乳糖、可溶性淀粉等多种碳源和硫酸铵、氯化铵、硝酸铵、硝酸钾、尿素等多种氮源进行生长代谢并表现出较强的解磷能力,在C/N 10∶1~60∶1、初始pH 7~8的条件下生长情况较好且解磷能力较高.该菌株有很强的产酸能力,在培养过程中培养液pH由7.00~7.50下降至2.06~4.87;在4种磷源培养液中的最高解磷量分别为磷酸三钙(869.62 mg·L^-1)>磷矿粉(233.56 mg·L^-1)>磷酸铝(44.77 mg·L^-1)>磷酸铁(28.42 mg·L^-1).Pearson相关分析表明,菌株在磷酸三钙、磷矿粉和磷酸铁培养液中的解磷量与pH的变化之间呈极显著负相关关系,在磷酸铝培养液中无显著相关关系.菌株PSF1解磷能力强,生长条件广,推测其在土壤中有较强的解磷能力.  相似文献   

19.
在林肯链霉菌生物合成林可霉素代谢调节的研究中,发现硝酸盐可明显促进林可霉素的生物合成.加入硝酸钾0.8%,林肯链霉菌合成林可霉素的产量可增加37%.在发酵96h之前加入硝酸盐均能促进林可霉毒的合成,但产量的增加随加入时间的延迟而降低.硝酸钾在促进产量的同时,使菌体生长减少,看来硝酸盐对林可霉素的合成与菌体生长之间起着调节作用.洗涤菌体试验指出,硝酸盐的加入诱导了林可霉素合成所需要的酶系,这可能是加入硝酸盐后,产生进一步氮代谢的结果;蛋白胨不能代替硝酸盐,进一步说明硝酸钾的作用并不是作为氮源利用.在蛋白质合成抑制剂氯霉素存在下,硝酸盐不再能促进林可霉素的合成,说明氯霉素抑制了硝酸盐或其代谢中间物所诱导的酶系的合成.同时还报导了镁盐促进林可霉素生物合成现象的初步观察结果.硫酸镁在促进林可霉素产量提高的同时,使菌体生长延迟.硫酸镁的这种作用机制可能是通过磷酸镁铵沉淀,降低了培养基中游离氨和可溶性磷酸盐浓度,解除了铵盐和磷酸盐对林可霉素合成的抑制.  相似文献   

20.
The effect of a revised Linsmaier-Skoog (LS) medium on betacyanin production was investigated in suspension cultures of table beet (Beta vulgaris L.). The effects of a high iron concentration and low concentration of zinc on betacyanin production were not cumulative. The composition of the new revised medium for high betacyanin production was established by reducing the concentration of inorganic nitrogen (30 mM), modifying the ratio of ammonium to nitrate (1:14), reducing the concentration of zinc (0.0003 mM), and removing copper and cobalt. The revised LS medium enabled the maximum betacyanin yield of 550 mg/l to be obtained from a 14-day culture. This medium promoted the betacyanin production in three types of cell line differing in the betacyanin productivity. The betacyanin productivity (40 mg/l?day) was higher than that quoted in any other previous reports.  相似文献   

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