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1.
Chia-Hung Su Liang-Jung Chien James Gomes Yu-Sheng Lin Yuan-Kun Yu Jhang-Song Liou Rong-Jhih Syu 《Journal of applied phycology》2011,23(5):903-908
Reserve lipids of microalgae are promising for biodiesel production. However, optimization of cultivation conditions for both
biomass yield and lipid production of microalgae is a contradictory problem because required conditions for both targets are
different. In this study, a two-stage cultivation strategy is proposed to enhance lipid production of the microalga Nannochloropsis oculata. Biomass growth and lipid production were carried out in two separate and non-interacting stages. In first-stage cultivation,
microalgae were cultivated in optimal conditions for cell growth. Then, microalgae were harvested and transferred into a growth-limited
environment, thus enhancing lipid production of microalgae. Here, optimization of the lipid production stage (second stage)
with respect to different levels of inoculum concentration, salinity of culture broth, and intensity of irradiance was performed.
The results show that irradiance exhibits a significant influence on lipid production. The highest lipid productivity of 0.324 g L−1 day−1 was obtained with an inoculum concentration of 2.3 g L−1, a salinity of 35 g L−1, and an irradiance of 500 μmol photons m−2 s−1. The final yield of lipid obtained from the two-stage process was 2.82-times higher than that from traditional single-stage
batch cultivation systems. 相似文献
2.
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
3.
Li Liu Xiaoli Fan Junwei Zhang Meiling Yan Manzhu Bao 《In vitro cellular & developmental biology. Plant》2009,45(6):673-680
In this study, we have demonstrated that Zoysia japonica callus induced from mature seeds can produce high frequencies of plant regeneration and somatic embryogenesis, even following
a prolonged period of subculturing. Initial callus cultures were induced from mature seeds of Japanese lawngrass (Z. japonica Steud.) incubated on a medium containing major N6 medium salts, minor Murashige and Skoog (MS) medium salts, and modified MS medium organic elements supplemented with 3 mg
L−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.01–0.02 mg L−1 6-benzyladenine. Compact callus were selected and subcultured monthly on a medium containing 2 mg L−1 2,4-D, 0.5 mg L−1 kinetin, 500 mg L−1 casein hydrolysate, 500 mg L−1 proline, and 500 mg L−1 myoinositol. Callus maintained in vitro for 18 mo could be induced to regenerate plantlets with a frequency of >90%. By contrast, 36-mo-old callus cultures failed
to produce normal shoot regeneration. However, the addition of CuSO4 to the subculture media maintained >90% regeneration frequencies in such long-term callus cultures. Histological observations
revealed that plant regeneration occurred both through somatic embryogenesis and organogenesis pathways. The ability to sustainable
regeneration in long-term callus cultures will be valuable to the program of genetic transformation and somaclonal variant
selection. 相似文献
4.
Chris J. Hulatt Aino-Maija Lakaniemi Jaakko A. Puhakka David N. Thomas 《Bioenergy Research》2012,5(3):669-684
Mass culture of microalgae is a potential alternative to cultivation of terrestrial crops for bioenergy production. However, microalgae require nitrogen fertiliser in quantities much higher than plants, and this has important consequences for the energy balance of these systems. The effect of nitrogen fertiliser supplied to microalgal bubble-column photobioreactor cultures was investigated using different nitrogen sources (nitrate, urea, ammonium) and culture conditions (air, 12% CO2). In 20 L cultivations, maximum biomass productivity for Chlorella vulgaris cultivated using nitrate and urea was 0.046 and 0.053 g L−1 day−1, respectively. Maximum biomass productivity for Dunaliella tertiolecta cultivated using nitrate, urea and ammonium was 0.033, 0.038 and 0.038 g L−1 day−1, respectively. In intensive bubble-column photobioreactors using 12% CO2, maximum productivity reached 0.60 and 0.83 g L−1 day−1 for C. vulgaris and D. tertiolecta, respectively. Recycling of nitrogen within the photobioreactor system via algal exudation of nitrogenous compounds and bacterial activity was identified as a potentially important process. The energetic penalty incurred by supply of artificial nitrogen fertilisers, phosphorus, power and CO2 to microalgal photobioreactors was investigated, although analysis of all energy burdens from biomass production to usable energy carriers was not conducted. After subtraction of the power, nitrogen and phosphorus energy burdens, maximum net energy ratios for C. vulgaris and D. tertiolecta cultivated in bubble columns were 1.82 and 2.10. Assuming CO2 was also required from a manufactured source, the net energy ratio decreased to 0.09 and 0.11 for C. vulgaris and D. tertiolecta, so that biomass production in this scenario was unsustainable. Although supply of nitrogen is unlikely to be the most energetically costly factor in sparged photobioreactor designs, it is still a very significant penalty. There is a need to optimise both cultivation strategies and recycling of nitrogen in order to improve performance. Data are supported by measurements including biochemical properties (lipid, protein, heating value) and bacterial number by epifluorescence microscopy. 相似文献
5.
Jonny E. Scherwinski-Pereira Rodrigo S. da Guedes Paulo César P. FerminoJr Tatiane L. Silva Frederico Henrique S. Costa 《In vitro cellular & developmental biology. Plant》2010,46(4):378-385
An efficient procedure has been developed for inducing somatic embryogenesis and regeneration of plants from tissue cultures
of oil palm (Elaeis guineensis Jacq.). Thin transverse sections (thin cell layer explants) of different position in the shoot apex and leaf sheath of oil
palm were cultivated in Murashige and Skoog (MS) (Physiol Plant 15:473–497, 1962) medium supplemented with 0–450 μM picloram and 2,4-D with 3.0% sucrose, 500 mg L−1 glutamine, and 0.3 g L−1 activated charcoal and gelled with 2.5 g L−1 Phytagel. Embryogenic calluses were evaluated 12 wk after inoculation. Picloram (450 μM) was effective in inducing embryogenic
calluses in 41.5% of the basal explants. Embryogenic calluses were maintained on a maturation medium composed of basal media,
plus 0.6 μM NAA and 12.30 μM 2iP, 0.3 g L−1 activated charcoal, and 500 mg L−1 glutamine, with subcultures at 4-wk intervals. Somatic embryos were converted to plants on MS medium with macro- and micronutrients
at half-strength, 2% sucrose, and 1.0 g L−1 activated charcoal and gelled with 2.5 g L−1 Phytagel. 相似文献
6.
Sirisansaneeyakul S Singhasuwan S Choorit W Phoopat N Garcia JL Chisti Y 《Marine biotechnology (New York, N.Y.)》2011,13(5):928-941
The microalgae Chlorella protothecoides UTEX 25, Chlorella sp. TISTR 8991, and Chlorella sp. TISTR 8990 were compared for use in the production of biomass and lipids under photoautotrophic conditions. Chlorella sp. TISTR 8990 was shown to be potentially suitable for lipid production at 30°C in a culture medium that contained only
inorganic salts. For Chlorella sp. TISTR 8990 in optimal conditions in a stirred tank photobioreactor, the lipid productivity was 2.3 mg L−1 h−1 and after 14 days the biomass contained more than 30% lipids by dry weight. To attain this, the nitrogen was provided as
KNO3 at an initial concentration of 2.05 g L−1 and chelated ferric iron was added at a concentration of 1.2 × 10−5 mol L−1 on the ninth day. Under the same conditions in culture tubes (36 mm outer diameter), the biomass productivity was 2.8-fold
greater than in the photobioreactor (0.125 m in diameter), but the lipid productivity was only 1.2-fold higher. Thus, the
average low-light level in the photobioreactor actually increased the biomass specific lipid production compared to the culture
tubes. A light-limited growth model closely agreed with the experimental profiles of biomass production, nitrogen consumption,
and lipid production in the photobioreactor. 相似文献
7.
High-throughput screening of microalgae for use as a potential feedstock for biodiesel requires a reliable method for the
rapid detection of intracellular neutral lipid content. In this study, we report a modified and improved Nile Red (NR) fluorescence
staining procedure for use as a rapid and sensitive screening tool to estimate levels of intracellular neutral lipid in the
picopleustonic microalgae, Nannochloropsis sp. Addition of either glycerol or dimethyl sulfoxide (DMSO) into microalgae cultures greatly enhances lipid staining efficiency
and increases the fluorescence intensity of stained cells. The optimized procedure requires glycerol and DMSO at the concentration
of 0.1 and 0.165 g mL−1, respectively, for peak fluorescence in a live culture of Nannochloropsis sp. Incubation for 5 min for glycerol-NR staining and 10 min for DMSO-NR staining at room temperature, in darkness, is used for
the NR concentration of 0.3 and 0.7 μg mL−1 for glycerol and DMSO, respectively. For the selection of lipid-rich cells of Nannochloropsis sp. using flow cytometric cell sorting, the glycerol-NR procedure is recommended as glycerol, unlike DMSO, does not inhibit
subsequent growth of sorted cells. 相似文献
8.
Juan Wang Wenyuan Gao Jian Zhang Tao Huang Tiantian Wen Liming Zhang Luqi Huang 《Plant Growth Regulation》2011,63(3):217-223
In this article, ginsenosides and polysaccharide contents in suspension cells and native roots of Panax quinquefolium L. were studied. In order to enhance the contents of ginsenosides and polysaccharide in P. quinquefolium suspension cells, we tested the effects of lactoalbumin hydrolysate on the growth of P. quinquefolium suspension cell, synthesis of ginsenosides and polysaccharide in flask and bioreactor. In flask culture, cells growth ratio
was significantly enhanced by the addition of lower concentration of lactoalbumin hydrolysate. Addition of 100 mg L−1 lactoalbumin hydrolysate significantly enhanced the contents of total saponins (5.44 mg g−1 DW) and the contents were 3.89-fold over the control group. Addition of lactoalbumin hydrolysate significantly promoted the
accumulation of polysaccharide, except 200 mg L−1 lactoalbumin hydrolysate. The highest total saponins yield (36.72 mg L−1 DW) and polysaccharide yield (0.83 g L−1 DW) were obtained at 100 mg L−1 lactoalbumin hydrolysate. In a 5-L stirred tank bioreactor, the highest contents of total saponins and TRb group ginsenosides
were achieved on day 26, while the effect of lactoalbumin hydrolysate on the contents of TRg group ginsenosides were insignificant.
This result suggests that lactoalbumin hydrolysate might have triggered the enzyme activities for the synthesis of TRb group
ginsenosides. Overall, the highest total saponins yield (31.37 mg L−1 DW) and polysaccharide yield (1.618 g L−1 DW) were obtained on day 26 and day 24 respectively and the polysaccharide yield was 1.95-fold higher than the shake flask
culture (0.83 g L−1 DW). These results provided theoretical reference for two-stage culture in suspension cells of P. quinquefolium in bioreactor. 相似文献
9.
Survase SA Jurgens G van Heiningen A Granström T 《Applied microbiology and biotechnology》2011,91(5):1305-1313
Clostridium beijerinckii DSM 6423 was studied using different continuous production methods to give maximum and stable production of isopropanol and
n-butanol. In a single-stage continuous culture, when wood pulp was added as a cell holding material, we could increase the
solvent productivity from 0.47 to 5.52 g L−1 h−1 with the yield of 54% from glucose. The overall solvent concentration of 7.51 g L−1 (39.4% isopropanol and 60.6% n-butanol) with the maximum solvent productivity of 0.84 g L−1 h−1 was obtained with two-stage continuous culture. We were able to run the process for more than 48 overall retention times
without losing the ability to produce solvents. 相似文献
10.
Plant gum as an elicitor for guggulsterone production in cell cultures of Commiphora wightii is reported for the first time. Guggulsterone production increased 2.4 fold in the cell cultures by gum Arabic (100 mg l−1), while mesquite gum elicited 2 fold. The cells treated with gum Arabic at 7th and 9th day accumulated enhanced guggulsterones
within 24 h, which increased further up to 48 h and then declined. The cells treated at 9th day accumulated higher amount
(218 μg l−1) of guggulsterones after 48 h of elicitation as compared to cells treated at 7th day (164 μg l−1). The optimized elicitation conditions were used in vessels of varying capacity where maximum yield of 285 μg l−1 of guggulsterones was recorded in 3 l shake flasks. These experiments enabled highest guggulsterones yield in a short duration
of 11 days in cell cultures of C. wightii. 相似文献
11.
Clemens G. Borkenstein Josef Knoblechner Heike Frühwirth Michael Schagerl 《Journal of applied phycology》2011,23(1):131-135
The present study reviews the options of cultivating the green alga, Chlorella emersonii, under photoautotrophic conditions with flue gas derived from a cement plant. It was conducted in the Lafarge Perlmooser
plant in Retznei, Austria, where stone coal and various surrogate fuels such as used tyres, plastics and meat-and-bone meal
are incinerated for heating limestone. During 30 days of cultivation, flue gas had no visible adverse effects compared to
the controls grown with pure CO2. The semi-continuous cultivation with media recycling was performed in 5.5-L pH-stat photobioreactors. The essay using CO2 from flue gas yielded a total of 2.00 g L−1 microalgal dry mass and a CO2 fixation of 3.25 g L−1. In the control, a total of 2.06 g L−1 dry mass was produced and 3.38 g L−1 CO2 was fixed. Mean growth rates were between 0.10 day−1 (control) and 0.13 day−1 (flue gas). No accumulation of flue gas residues was detected in the culture medium. At the end of the experiment, however,
the concentration of lead was three times higher in algal biomass compared to the control, indicating that cultures aerated
with this type of flue gas should not be used as food supplements or animal feed. 相似文献
12.
Continuous production of acetone, n-butanol, and ethanol (ABE) was carried out using immobilized cells of Clostridium acetobutylicum DSM 792 using glucose and sugar mixture as a substrate. Among various lignocellulosic materials screened as a support matrix,
coconut fibers and wood pulp fibers were found to be promising in batch experiments. With a motive of promoting wood-based
bio-refinery concept, wood pulp was used as a cell holding material. Glucose and sugar mixture (glucose, mannose, galactose,
arabinose, and xylose) comparable to lignocellulose hydrolysate was used as a substrate for continuous production of ABE.
We report the best solvent productivity among wild-type strains using column reactor. The maximum total solvent concentration
of 14.32 g L−1 was obtained at a dilution rate of 0.22 h−1 with glucose as a substrate compared to 12.64 g L−1 at 0.5 h−1 dilution rate with sugar mixture. The maximum solvent productivity (13.66 g L−1 h−1) was obtained at a dilution rate of 1.9 h−1 with glucose as a substrate whereas solvent productivity (12.14 g L−1 h−1) was obtained at a dilution rate of 1.5 h−1 with sugar mixture. The immobilized column reactor with wood pulp can become an efficient technology to be integrated with
existing pulp mills to convert them into wood-based bio-refineries. 相似文献
13.
Liu J Zhang Z Liu Z Zhu H Dang H Lu J Cui Z 《Marine biotechnology (New York, N.Y.)》2011,13(5):837-844
The aim of this work was to optimize the fermentation parameters in the shake-flask culture of marine bacterium Wangia sp. C52 to increase cold-adapted amylase production using two statistical experimental methods including Plackett–Burman
design, which was applied to find the key ingredients for the best medium composition, and response surface methodology, which
was used to determine the optimal concentrations of these components. The results showed starch, tryptone, and initial pH
had significant effects on the cold-adapted amylase production. A central composite design was then employed to further optimize
these three factors. The experimental results indicated that the optimized composition of medium was 6.38 g L−1 starch, 33.84 g L−1 tryptone, 3.00 g L−1 yeast extract, 30 g L−1 NaCl, 0.60 g L−1 MgSO4 and 0.56 g L−1 CaCl2. The optimized cultivation conditions for amylase production were pH 7.18, a temperature of 20°C, and a shaking speed of
180 rpm. Under the proposed optimized conditions, the amylase experimental yield (676.63 U mL−1) closely matched the yield (685.60 U mL−1) predicted by the statistical model. The optimization of the medium contributed to tenfold higher amylase production than
that of the control in shake-flask experiments. 相似文献
14.
Production of hexanoic acid from d-galactitol by a newly isolated Clostridium sp. BS-1 总被引:1,自引:0,他引:1
Byoung Seung Jeon Byung-Chun Kim Youngsoon Um Byoung-In Sang 《Applied microbiology and biotechnology》2010,88(5):1161-1167
In a study screening anaerobic microbes utilizing d-galactitol as a fermentable carbon source, four bacterial strains were isolated from an enrichment culture producing H2, ethanol, butanol, acetic acid, butyric acid, and hexanoic acid. Among these isolates, strain BS-1 produced hexanoic acid
as a major metabolic product of anaerobic fermentation with d-galactitol. Strain BS-1 belonged to the genus Clostridium based on phylogenetic analysis using 16S rRNA gene sequences, and the most closely related strain was Clostridium sporosphaeroides DSM 1294T, with 94.4% 16S rRNA gene similarity. In batch cultures, Clostridium sp. BS-1 produced 550 ± 31 mL L−1 of H2, 0.36 ± 0.01 g L−1 of acetic acid, 0.44 ± 0.01 g L−1 of butyric acid, and 0.98 ± 0.03 g L−1 of hexanoic acid in a 4-day cultivation. The production of hexanoic acid increased to 1.22 and 1.73 g L−1 with the addition of 1.5 g L−1 of sodium acetate and 100 mM 2-(N-morpholino)ethanesulfonic acid (MES), respectively. Especially when 1.5 g L−1 of sodium acetate and 100 mM MES were added simultaneously, the production of hexanoic acid increased up to 2.99 g L−1. Without adding sodium acetate, 2.75 g L−1 of hexanoic acid production from d-galactitol was achieved using a coculture of Clostridium sp. BS-1 and one of the isolates, Clostridium sp. BS-7, in the presence of 100 mM MES. In addition, volatile fatty acid (VFA) production by Clostridium sp. BS-1 from d-galactitol and d-glucose was enhanced when a more reduced culture redox potential (CRP) was applied via addition of Na2S·9H2O. 相似文献
15.
Md. Abdullahil Baque Abdullah Elgirban Eun-Jung Lee Kee-Yoeup Paek 《Acta Physiologiae Plantarum》2012,34(2):405-415
The effect of initial sucrose concentration was investigated in root suspension cultures of Morinda citrifolia to improve root growth and secondary metabolites production, i.e. anthraquinone, phenolics and flavonoids. Besides, oxidative
stress level, antioxidant enzymes activity and membranes damage under different sucrose concentration were estimated. A 5%
sucrose supply was shown to be optimal for the production of root dry mass, but higher sucrose concentrations of 7–9% inhibited
the accumulation of root dry weight (DW). However, the maximum production of anthraquinone (251.89 g L−1 DW), phenolics (165.14 g L−1 DW) and flavonoids (163.56 g L−1 DW) were achieved at 1% sucrose-treated culture, which may be a source carbon skeletons for secondary metabolism. At the
same time was observed low oxidative damage, which could be associated with high levels of secondary metabolites and the increased
activity of catalase. Although, catalase (CAT) activity were stimulated at 7–9% sucrose-treated cultures, high accumulation
of hydrogen peroxide (H2O2) and peroxidation of lipid (MDA) was induced. The observed high activity of CAT and guaiacol peroxidase (G-POD) were not
sufficient enough to mitigate the toxic effect of H2O2. 相似文献
16.
Juan Wang Wen-Yuan Gao Jian Zhang Tao Huang Tian-Tian Wen Lu-Qi Huang 《Acta Physiologiae Plantarum》2011,33(3):861-866
Lactoalbumin hydrolysate (LH) at 100 mg L−1 with methyl jasmonate (MJ) at 2 mg L−1 synergistically stimulated ginsenoside accumulation in Panax quinquefolium cells compared with 100 mg L−1 LH. Combination elicitors led to higher ginsenoside productivity (45.93 mg L−1) than single treatment of 100 mg L−1 LH (31.37 mg L−1). This present result will be helpful in providing a tool for enhancing the productivity of ginsenoside by Panax quinquefolium cell cultures on a commercial scale. 相似文献
17.
Arabidopsis halleri is increasingly employed as a model plant for studying heavy metal hyperaccumulation. With the aim of providing valuable
tools for studies on cellular physiology and molecular biology of metal tolerance and transport, this study reports the development
of successful and highly efficient methods for the in vitro regeneration of A. halleri plants and production of stable cell suspension lines. Plants were regenerated from leaf explants of A. halleri via a three-step procedure: callus induction, somatic embryogenesis and shoot development. Efficiency of callus proliferation
and regeneration depended on the initial callus induction media and was optimal in the presence of 1 mg L−1 2,4-dichlorophenoxyacetic acid, and 0.05 mg L−1 benzylaminopurine. Subsequent shoot and root regeneration from callus initiated under these conditions reached levels of
100% efficiency. High friability of the callus supported the development of cell suspension cultures with minimal cellular
aggregates. Characterization of regenerated plants and cell cultures determined that they maintained not only the zinc tolerance
and requirement of the whole plant but also the ability to accumulate zinc; with plants accumulating up to 50.0 μmoles zinc
g−1 FW, and cell suspension cultures 30.9 μmoles zinc g−1 DW. Together this work will provide the experimental basis for furthering our knowledge of A. halleri as a model heavy metal hyperaccumulating plant. 相似文献
18.
Guggulsterone, a hypolipidemic natural agent, is produced in resin canals of the plant Commiphora wightii. In this study, the stimulatory effects of growth retardants [ALAR (N,N-dimethylaminosuccinamic acid) and CCC (chlormequat chloride)] and fungal elicitor on guggulsterone accumulation in cell cultures
of C. wightii are reported. CCC at 1 mg l−1 enhanced guggulsterone content (~123 μg l−1) when added on the fifth day after inoculation, while ALAR at 2.5 mg l−1 increased guggulsterone content (~116 μg l−1) when added on the tenth day. In a two-stage fed-batch process, combined treatment with fungal elicitor and growth retardant
caused a significant increase (~353 μg l−1) in guggulsterone content in cell cultures after 17 days of growth. This represents an approximately fivefold increase over
the guggulsterone contents in initial cultures of this plant. 相似文献
19.
N Kiran Sree M Sridhar K Suresh I M Banat L Venkateswar Rao 《Journal of industrial microbiology & biotechnology》2000,24(3):222-226
A repeated batch fermentation system was used to produce ethanol using an osmotolerant Saccharomyces cerevisiae (VS3) immobilized in calcium alginate beads. For comparison free cells were also used to produce ethanol by repeated batch fermentation.
Fermentation was carried for six cycles with 125, 250 or 500 beads using 150, 200 or 250 g glucose L−1 at 30°C. The maximum amount of ethanol produced by immobilized VS3 using 150 g L−1 glucose was only 44 g L−1 after 48 h, while the amount of ethanol produced by free cells in the first cycle was 72 g L−1. However in subsequent fed batch cultures more ethanol was produced by immobilized cells compared to free cells. The amount
of ethanol produced by free cells decreased from 72 g L−1 to 25 g L−1 after the fourth cycle, while that of immobilized cells increased from 44 to 72 g L−1. The maximum amount of ethanol produced by immobilized VS3 cells using 150, 200 and 250 g glucose L−1 was 72.5, 93 and 87 g ethanol L−1 at 30°C. Journal of Industrial Microbiology & Biotechnology (2000) 24, 222–226.
Received 16 September 1999/ Accepted in revised form 22 December 1999 相似文献
20.
Andreazza R Okeke BC Pieniz S Brandelli A Lambais MR Camargo FA 《Biological trace element research》2011,143(2):1182-1192
Environmental copper contamination is a serious human health problem. Copper reductase is produced by microorganisms to facilitate
copper uptake by ATPases into the cells increasing copper biosorption. This study assessed the reduction of Cu(II) by cell-free
extracts of a highly copper-resistant bacterium, Pseudomonas sp. strain NA, isolated from vineyard soil contaminated with copper. Both intact cells and cell-free extract of Pseudomonas sp. strain NA displayed substantial reduction of Cu(II). Intact cells reduced more then 80 mg L−1 of Cu(II) from medium amended with 200 mg L−1 of copper after 24 h of incubation. Cell-free extract of the isolate reduced more than 65% of the Cu(II) at initial copper
concentration of 200 mg L−1 after 24 h. Soluble protein production was high at 72 h of incubation at 100 mg L−1 of copper, with more then 60 μg L−1 of total soluble protein in cell-free extract recorded. Cu(II) reduction by isolate NA was increased when copper concentration
increased for both intact cells and cell-free extract. Results indicate that Pseudomonas sp. strain NA produces copper reductase enzyme as the key mechanism of copper biotransformation. 相似文献