共查询到20条相似文献,搜索用时 15 毫秒
1.
Joshua Otieno Ogweno Wen Hai Hu Xing Shun Song Kai Shi Wei Hua Mao Yan Hong Zhou Jing Quan Yu 《Plant Growth Regulation》2010,60(3):175-182
Detached leaves of tomato (Lycopersicon esculentum Mill.) experienced photoinhibition associated with sharp reductions in net photosynthetic rate (Pn), quantum efficiency of
PSII (ΦPSII) and photochemical quenching (qP) even though they were exposed to mild light intensity (400 μmol m−2 s−1 PPFD) at 28°C. Photoinhibition and the reduction in Pn, ΦPSII and qP, however, were significantly alleviated by 1 mg l−1 ABA, 0.1 mg l−1
N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU) and 0.01 mg l−1 24-epibrassinolide (EBR). Higher concentrations, however, reduced the effects or even exacerbated the occurrence of photoinhibition.
Superoxide dismutase and ascorbate peroxidase activity in leaves increased with the increases in ABA concentration within
1–100 mg l−1, CPPU concentration within 0.1–10 mg l−1 and EBR concentration within 0.01–1.0 mg l−1. Catalase and guaiacol peroxidase activity also increased with the increase in EBR concentration but CPPU and ABA treatments
at higher concentrations caused a decrease. Malondialdehyde (MDA) content decreased with the increase in CPPU concentration.
ABA and EBR, however, decreased MDA concentration only at 1 and 0.01 mg l−1, respectively. In conclusion, detached leaves had increased sensitivity to PSII photoinhibition. Photoinhibition-induced
decrease in photosynthesis, however, was significantly alleviated by EBR, CPPU and ABA at a proper concentration. 相似文献
2.
The effects of humic acid (HA) on azo dye decolorization by Shewanella oneidensis MR-1 were studied. It was found that HA species isolated from different sources could all accelerate the decolorization of
Acid Red 27 (AR27). Anoxic and anaerobic conditions were required for the enhancement of azo dye decolorization by HA. In
the presence of 50 mg DOC L−1 Aldrich HA, 15–29% increases in decolorization efficiencies of azo dyes with different structures were achieved in 11 h.
The enhancing effects increased with the increase of HA concentrations ranging from 25 to 150 mg DOC L−1, and the decolorization rates were directly proportional to the HA concentrations when they were below 100 mg DOC L−1. Lactate and formate were good electron donors for AR27 decolorization in the presence of HA. Both nitrate (0.1–3.0 mM) and
nitrite (0.3–1.2 mM) inhibited AR27 decolorization in the presence of HA, and negligible decolorization was observed before
their removal. Soluble FeCl3 could accelerate the decolorization process in the presence of HA, whereas insoluble hematite could not. These findings may
affect the understanding of bioremediation of azo dye-polluted environments and help improve the treatment of azo dye wastewaters. 相似文献
3.
To identify the controls on dissolved organic carbon (DOC) production, we incubated soils from 18 sites, a mixture of 52 forest
floor and peats and 41 upper mineral soil samples, at three temperatures (3, 10, and 22°C) for over a year and measured DOC
concentration in the leachate and carbon dioxide (CO2) production from the samples. Concentrations of DOC in the leachate were in the range encountered in field soils (<2 to >50 mg l−1). There was a decline in DOC production during the incubation, with initial rates averaging 0.03–0.06 mg DOC g−1 soil C day−1, falling to averages of 0.01 mg g−1 soil C day−1; the rate of decline was not strongly related to temperature. Cumulative DOC production rates over the 395 days ranged from
less than 0.01 to 0.12 mg g−1 soil C day−1 (0.5–47.6 mg g−1 soil C), with an average of 0.021 mg g−1 soil C day−1 (8.2 mg g−1 soil C). DOC production rate was weakly related to temperature, equivalent to Q10 values of 0.9 to 1.2 for mineral samples and 1.2 to 1.9 for organic samples. Rates of DOC production in the organic samples
were correlated with cellulose (positively) and lignin (negatively) proportion in the organic matter, whereas in the mineral
samples C and nitrogen (N) provided positive correlations. The partitioning of C released into CO2–C and DOC showed a quotient (CO2–C:DOC) that varied widely among the samples, from 1 to 146. The regression coefficient of CO2–C:DOC production (log10 transformed) ranged from 0.3 to 0.7, all significantly less than 1. At high rates of DOC production, a smaller proportion
of CO2 is produced. The CO2–C:DOC quotient was dependent on incubation temperature: in the organic soil samples, the CO2–C:DOC quotient rose from an average of 6 at 3 to 16 at 22°C and in the mineral samples the rise was from 7 to 27. The CO2–C:DOC quotient was related to soil pH in the organic samples and C and N forms in the mineral samples. 相似文献
4.
Weihong Zhong Weijian Wang Zhuoyi Kong Bin Wu Li Zhong Xuanzhen Li Ji Yu Fuming Zhang 《Applied microbiology and biotechnology》2011,89(2):293-302
In a water-organic solvent, two-phase conversion system, CoQ10 could be produced directly from solanesol and para-hydroxybenzoic acid (PHB) by free cells of Sphingomonas sp. ZUTE03 and CoQ10 concentration in the organic solvent phase was significantly higher than that in the cell. CoQ10 yield reached a maximal value of 60.8 mg l−1 in the organic phase and 40.6 mg g−1-DCW after 8 h. CoQ10 also could be produced by gel-entrapped cells in the two-phase conversion system. Soybean oil and hexane were found to be
key substances for CoQ10 production by gel-entrapped cells of Sphingomonas sp. ZUTE03. Soybean oil might improve the release of CoQ10 from the gel-entrapped cells while hexane was the suitable solvent
to extract CoQ10 from the mixed phase of aqueous and organic. The gel-entrapped cells could be re-used to produce CoQ10 by a repeated-batch culture. After 15 repeats, the yield of CoQ10 kept at a high level of more than 40 mg l−1. After 8 h conversion under optimized precursor’s concentration, CoQ10 yield of gel-trapped cells reached 52.2 mg l−1 with a molar conversion rate of 91% and 89.6% (on PHB and solanesol, respectively). This is the first report on enhanced
production of CoQ10 in a two-phase conversion system by gel-entrapped cells of Sphingomonas sp. ZUTE03. 相似文献
5.
Ana Mendes-Ferreira Catarina Barbosa Virgílio Falco Cecília Leão Arlete Mendes-Faia 《Journal of industrial microbiology & biotechnology》2009,36(4):571-583
The aim of this study was to evaluate the combined effect of initial nitrogen content on the production of hydrogen sulphide
and other volatile compounds during alcoholic fermentation. For that propose, three commercial wine strains of Saccharomyces cerevisiae were used to ferment synthetic grape juice media under different nitrogen concentrations. H2S was measured throughout fermentations and other aroma compounds were analyzed at the end of the experiments. The trigger
levels at which an inverse relationship between the initial nitrogen present in media and total H2S production varied among the three strains tested. For UCD522 and PYCC4072, the highest H2S levels were produced in media with 267 mg N l−1 of initial nitrogen, whereas the lowest levels were detected with nitrogen limitation/starvation conditions (66 mg N l−1). Moreover, 21 other aroma compounds belonging to different chemical classes were identified and quantified by solid phase
micro-extraction (SPME) coupled to gas chromatography–mass spectrometry (GC–MS). The initial nitrogen concentration more than
yeast strain had a decisive effect on the final aroma composition, suggesting that modulation of nutrients emerges as a useful
tool for producing desired flavour and odour compounds. 相似文献
6.
Behzad Ahmadi Khoshnood Alizadeh Jaime A. Teixeira da Silva 《Plant Cell, Tissue and Organ Culture》2012,109(3):525-533
The effects of three periods of incubation (10, 20 and 30 min) at different levels of bleomycin (0, 0.1, 0.2, 0.3, 0.4 and
0.5 μg ml−1), as well as three periods of exposure (12, 24 and 48 h) to different levels of the anti-auxin p-chlorophenoxyisobutyric acid (PCIB), including 1, 2, 3, 4 and 5 mg l−1, on microspore embryogenesis of rapeseed cv. ‘Amica’ were investigated. Microspore embryogenesis was significantly enhanced
following 20 min treatment with 0.2 μg ml−1 bleomycin compared with untreated cultures. Highest embryo yield (163 embryos Petri dish−1) was observed with 24 h treatment of 4 mg l−1 PCIB. The highest percentage of secondary embryogenesis was observed on B5 medium containing 0.15 mg l−1 of gibberellic acid (GA3) and 0.2 mg l−1 6-benzyladenine (BA) in 4–6 mm microspore-derived embryos (MDEs). Most callus formed on B5 medium containing 0.15 mg l−1 GA3, 0.1 mg l−1 BA and 0.1 mg l−1 indole-3-acetic acid (IAA) when 4–6 mm embryos were used. Regeneration was highest on B5 medium containing 0.05 mg l−1 GA3 or 0.1 mg l−1 BA and 0.2 mg l−1 IAA with 2–4 mm embryos. Microspore embryogenesis and plant regeneration could be improved by both bleomycin and PCIB when
the appropriate MDE length and phytohormone level were selected. 相似文献
7.
Kim HT Ko HJ Kim N Kim D Lee D Choi IG Woo HC Kim MD Kim KH 《Biotechnology letters》2012,34(6):1087-1092
A gene, alg7D, from Saccharophagus degradans, coding for a putative alginate lyase belonging to the family of polysaccharide lyase-7, was overexpressed in Escherichia coli. The properties of the recombinant Alg7D were characterized. The enzyme endolytically depolymerized alginate by β-elimination
into oligo-alginates with degrees of polymerization of 2–5. Its activity was maximal at 50°C and pH 7 and was slightly increased
in the presence of Na+. The K
M
, V
max
, k
cat
, and k
cat
/K
M
values were: 3 mg ml−1, 6.2 U mg−1, 1.9 × 10−2 s−1, and 6.3 × 10−3 mg−1 ml s−1, respectively. 相似文献
8.
Jana Woelfel Rhena Schumann Florian Peine Anita Flohr Aleksandra Kruss Jaroslaw Tegowski Philippe Blondel Christian Wiencke Ulf Karsten 《Polar Biology》2010,33(9):1239-1253
During summer 2007, Arctic microphytobenthic potential primary production was measured at several stations around the coastline
of Kongsfjorden (Svalbard, Norway) at ≤5 m water depth and at two stations at five different water depths (5, 10, 15, 20,
30 m). Oxygen planar optode sensor spots were used ex situ to determine oxygen exchange in the overlying water of intact sediment
cores under controlled light (ca. 100 μmol photons m−2 s−1) and temperature (2–4°C) conditions. Patches of microalgae (mainly diatoms) covering sandy sediments at water depths down
to 30 m showed high biomass of up to 317 mg chl a m−2. In spite of increasing water depth, no significant trend in “photoautotrophic active biomass” (chl a, ratio living/dead cells, cell sizes) and, thus, in primary production was measured at both stations. All sites from ≤5 to
30 m water depth exhibited variable rates of net production from −19 to +40 mg O2 m−2 h−1 (−168 to +360 mg C m−2 day−1) and gross production of about 2–62 mg O2 m−2 h−1 (17–554 mg C m−2 day−1), which is comparable to other polar as well as temperate regions. No relation between photoautotrophic biomass and gross/net
production values was found. Microphytobenthos demonstrated significant rates of primary production that is comparable to
pelagic production of Kongsfjorden and, hence, emphasised the importance as C source for the zoobenthos. 相似文献
9.
Motomi Genkai-Kato Miyuki Onishi Hideyuki Doi Kentaro Nozaki Kenji Yoshino Hitoshi Miyasaka Koji Omori 《Ecological Research》2008,23(6):1025-1032
We investigated the photosynthesis–light intensity (P–I) relationships of phytoplankton collected from a sublittoral sand
bank in the Seto Inland Sea, Japan, under different temperature conditions. In spite of low chlorophyll a concentration (<3 mg m−3), phytoplankton had considerably high photosynthetic potential (>10 mg C (mg chl a)−1 h−1) in the study area. Based on the P–I relationships, we conducted numerical simulation of areal primary production using published
data on water temperature, chlorophyll a concentration, and irradiance. The areal primary production ranged between 159 and 187 g C m−2 year−1. This production was within the range of typical values reported previously in deeper areas of the Seto Inland Sea. The productivity
in the sand bank area was discussed in relation to water current, allochthonous resource input, and fisheries. 相似文献
10.
Copper (II) complex of formulation [Cu–Phen–Tyr](H2O)](ClO4) (Phen = 1,10-phenanthroline, l-Tyr = l-tyrosine), has been prepared, and their induced DNA oxidative cleavage activity studied. The complex binds to DNA by intercalation,
as deduced from the absorption and fluorescence spectral data. Scatchard plots constructed from the absorption titration data
gave binding constant 2.44 × 104 M−1 of base pairs. Extensive hypochromism, broadening, and red shifts in the absorption spectra were observed. Upon binding to
DNA, the fluorescence from the DNA–ethidium bromide system was efficiently quenched by the copper (II) complex. Stern–Volmer
quenching constant 0.61 × 103 M−1 obtained from the linear quenching plots. [Cu–Phen–Tyr] complex efficiently cleave the supercoiled DNA to its nicked circular
form with gallic acid as biological reductant at appropriate complex concentration. The gallic acid as reductant could observably
improve copper (II) complex to DNA damage. The pseudo-Michaelis–Menten kinetic parameters (k
cat, K
M) were calculated to be 1.32 h−1 and 5.46 × 10−5 M for [Cu–Phen–Tyr] complex. Mechanistic studies reveal the involvement of superoxide anions and hydroxyl radical (HO·) as the reactive species under an aerobic medium. 相似文献
11.
The objective of this study was to improve the biological water–gas shift reaction for producing hydrogen (H2) by conversion of carbon monoxide (CO) using an anaerobic thermophilic pure strain, Carboxydothermus hydrogenoformans. Specific hydrogen production rates and yields were investigated at initial biomass densities varying from 5 to 20 mg volatile
suspended solid (VSS) L−1. Results showed that the gas–liquid mass transfer limits the CO conversion rate at high biomass concentrations. At 100-rpm
agitation and at CO partial pressure of 1 atm, the optimal substrate/biomass ratio must exceed 5 mol CO g−1 biomass VSS in order to avoid gas–liquid substrate transfer limitation. An average H2 yield of 94 ± 3% and a specific hydrogen production rate of ca. 3 mol g−1 VSS day−1 were obtained at initial biomass densities between 5 and 8 mg VSS−1. In addition, CO bioconversion kinetics was assessed at CO partial pressure from 0.16 to 2 atm, corresponding to a dissolved
CO concentration at 70°C from 0.09 to 1.1 mM. Specific bioactivity was maximal at 3.5 mol CO g−1 VSS day−1 for a dissolved CO concentration of 0.55 mM in the culture. This optimal concentration is higher than with most other hydrogenogenic
carboxydotrophic species. 相似文献
12.
Araújo SM Silva CF Moreira JJ Narain N Souza RR 《Journal of industrial microbiology & biotechnology》2011,38(9):1161-1169
In Brazil, the use of cashew apple (Anacardium occidentale L.) to obtain new products by biotechnological process represents an important alternative to avoid wastage of a large quantity
of this fruit, which reaches about 85% of the annual production of 1 million tons. This work focuses on the development of
an alcoholic product obtained by the fermentation of cashew apple juice. The inoculation with two different strains of yeast
Saccharomyces cerevisiae viz. SCP and SCT, were standardized to a concentration of 107 cells ml−1. Each inoculum was added to 1,500 ml of cashew must. Fermentation was performed at 28 ± 3°C and aliquots were withdrawn every
24 h to monitor soluble sugar concentrations, pH, and dry matter contents. The volatile compounds in fermented products were
analyzed using the gas chromatography/mass spectrometry (GC/MS) system. After 6 days, the fermentation process was completed,
cells removed by filtration and centrifugation, and the products were stabilized under refrigeration for a period of 20 days.
The stabilized products were stored in glass bottles and pasteurized at 60 ± 5°C/30 min. Both fermented products contained
ethanol concentration above 6% (v v−1) while methanol was not detected and total acidity was below 90 mEq l−1, representing a pH of 3.8–3.9. The volatile compounds were characterized by the presence of aldehyde (butyl aldehyde diethyl
acetal, 2,4-dimethyl-hepta-2,4-dienal, and 2-methyl-2-pentenal) and ester (ethyl α-methylbutyrate) representing fruity aroma.
The strain SCT was found to be better and efficient and this produced 10% more alcohol over that of strain SCP. 相似文献
13.
Ki-Hyun Park O-Mi Lee Ho-Il Jung Jin-Ha Jeong Young-Dong Jeon Dae-Youn Hwang Chung-Yeol Lee Hong-Joo Son 《Applied microbiology and biotechnology》2010,86(3):947-955
We isolated and characterized novel insoluble phosphate (P)-solubilizing bacteria tolerant to environmental factors like high
salt, low and high pHs, and low temperature. A bacterium M6 was isolated from a ginseng rhizospheric soil and confirmed to
belong to Burkholderia vietnamiensis by BIOLOG system and 16S rRNA gene analysis. The optimal cultural conditions for the solubilization of P were 2.5% (w/v) glucose, 0.015% (w/v) urea, and 0.4% (w/v) MgCl2·6H2O along with initial pH 7.0 at 35°C. High-performance liquid chromatography analysis showed that B. vietnamiensis M6 produced gluconic and 2-ketogluconic acids. During the culture, the pH was reduced with increase in gluconic acid concentration
and was inversely correlated with P solubilization. Insoluble P solubilization in the optimal medium was about 902 mg l−1, which was approximately 1.6-fold higher than the yield in NBRIP medium (580 mg l−1). B. vietnamiensis M6 showed resistance against different environmental stresses like 10–45°C, 1–5% (w/v) salt, and 2–11 pH range. The maximal concentration of soluble P produced by B. vietnamiensis M6 from Ca3(PO4)2, CaHPO4, and hydroxyapatite was 1,039, 2,132, and 1,754 mg l−1, respectively. However, the strain M6 produced soluble P with 20 mg l−1 from FePO4 after 2 days and 100 mg l−1 from AlPO4 after 6 days, respectively. Our results indicate that B. vietnamiensis M6 could be a potential candidate for the development of biofertilizer applicable to environmentally stressed soil. 相似文献
14.
Chavan SP Lokhande VH Nitnaware KM Nikam TD 《Applied microbiology and biotechnology》2011,89(6):1701-1707
The present study examined the effects of plant growth hormones, incubation period, biotic (Trametes versicolor, Mucor sp., Penicillium notatum, Rhizopus stolonifer, and Fusarium oxysporum) and abiotic (NaCl, MgSO4, FeSO4, ZnSO4, and FeCl3) elicitors on cell growth and α-tocopherol and pigment (red and yellow) productions in Carthamus tinctorius cell cultures. The cell growth and α-tocopherol and pigment contents improved significantly on Murashige and Skoog (MS) liquid
medium containing 50.0 μM α-naphthalene acetic acid (NAA) and 2.5 μM 6-Benzyladenine (BA) at 28 days of incubation period.
Incorporation of T. versicolor (50 mg l−1) significantly enhanced the production of α-tocopherol (12.7-fold) and red pigment (4.24-fold). Similarly, supplementation
of 30 mg l−1
T. versicolor (7.54-fold) and 70 mg l−1
Mucor sp. (7.40-fold) significantly increased the production of yellow pigment. Among abiotic elicitors, NaCl (50–70 mg l−1) and MgSO4 (10–30 mg l−1) significantly improved production of α-tocopherol (1.24-fold) and red pigment (20-fold), whereas yellow pigment content
increased considerably by all the abiotic elicitor treatments. Taken together, the present study reports improved productions
of α-tocopherol and the pigment as a stress response of safflower cell cultures exposed to these elicitors. 相似文献
15.
Kinetics of styrene biodegradation by <Emphasis Type="Italic">Pseudomonas</Emphasis> sp. E-93486 总被引:1,自引:0,他引:1
The research into kinetics of styrene biodegradation by bacterial strain Pseudomonas sp. E-93486 coming from VTT Culture Collection (Finland) was presented in this work. Microbial growth tests in the presence
of styrene as the sole carbon and energy source were performed both in batch and continuous cultures. Batch experiments were
conducted for initial concentration of styrene in the liquid phase changed in the range of 5–90 g m−3. The Haldane model was found to be the best to fit the kinetic data, and the estimated constants of the equation were: μ
m = 0.1188 h−1, K
S = 5.984 mg l−1, and K
i = 156.6 mg l−1. The yield coefficient mean value
Y\textxs\textapp Y_{\text{xs}}^{\text{app}} for the batch culture was 0.72 gdry cells weight (gsubstrate)−1. The experiments conducted in a chemostat at various dilution rates (D = 0.035–0.1 h−1) made it possible to determine the value of the coefficient for maintenance metabolism m
d = 0.0165 h−1 and the maximum yield coefficient value
Y\textxs\textM = 0.913 Y_{\text{xs}}^{\text{M}} = 0.913 . Chemostat experiments confirmed the high value of yield coefficient
Y\textxs\textapp Y_{\text{xs}}^{\text{app}} observed in the batch culture. The conducted experiments showed high activity of the examined strain in the styrene biodegradation
process and a relatively low sensitivity to inhibition of its growth at higher concentrations of styrene in the solution.
Such exceptional features of Pseudomonas sp. E-93486 make this bacterial strain the perfect candidate for technical applications. 相似文献
16.
Luz Allende Guillermo Tell Horacio Zagarese Ana Torremorell Gonzalo Pérez José Bustingorry Roberto Escaray Irina Izaguirre 《Hydrobiologia》2009,624(1):45-60
Shallow lakes often alternate between two possible states: one clear with submerged macrophytes, and another one turbid, dominated
by phytoplankton. A third type of shallow lakes, the inorganic turbid, result from high contents of suspended inorganic material,
and is characterized by low phytoplankton biomass and macrophytes absence. In our survey, the structure and photosynthetic
properties (based on 14C method) of phytoplankton were related to environmental conditions in these three types of lakes in the Pampa Plain. The
underwater light climate was characterized. Clear-vegetated lakes were more transparent (K
d 4.5–7.7 m−1), had high DOC concentrations (>45 mg l−1), low phytoplankton Chl a (1.6–2.7 μg l−1) dominated by nanoflagellates. Phytoplankton productivity and photosynthetic efficiency (α ~ 0.03 mgC mgChla
−1 h−1 W−1 m2) were relatively low. Inorganic-turbid lakes showed highest K
d values (59.8–61.4 m−1), lowest phytoplankton densities (dominated by Bacillariophyta), and Chl a ranged from 14.6 to 18.3 μg l−1. Phytoplankton-turbid lakes showed, in general, high K
d (4.9–58.5 m−1) due to their high phytoplankton abundances. These lakes exhibited the highest Chl a values (14.2–125.7 μg l−1), and the highest productivities and efficiencies (maximum 0.56 mgC mgChla
−1 h−1 W−1 m2). Autotrophic picoplankton abundance, dominated by ficocianine-rich picocyanobacteria, differed among the shallow lakes independently
of their type (0.086 × 105–41.7 × 105 cells ml−1). This article provides a complete characterization of phytoplankton structure (all size fractions), and primary production
of the three types of lakes from the Pampa Plain, one of the richest areas in shallow lakes from South America.
Handling editor: J. Padisak 相似文献
17.
The influence of increasing concentrations (0.1, 1.0 and 5.0 mg l−1) of fluoranthene (FLT) on growth, endogenous abscisic acid (ABA) level and primary photosynthetic processes in 21-day-old
pea plants (Pisum sativum L.) in vitro was investigated. Murashige and Skoog’s (MS) medium, with or without FLT, was enriched with indole-3-acetic
acid (IAA; 0.1 mg l−1) or a combination of IAA (0.1 mg l−1) plus N6-benzyladenine (BA; 0.1 mg l−1). The level of endogenous ABA significantly increased with increasing FLT concentrations in the presence of both IAA and
IAA plus BA. An increased level of endogenous ABA was observed in plants treated with IAA alone. The growth of shoot, callus
and the content of photosynthetic pigments (chlorophyll a and b, carotenoids), in both IAA- and IAA plus BA-treated plants, were significantly stimulated by FLT at its lowest concentration
(0.1 mg l−1) assayed in this study. However, FLT at higher concentrations (1.0 and 5.0 mg l−1) significantly inhibited all these parameters. Chlorophyll fluorescence imaging showed that FLT only at the highest concentration
(5.0 mg l−1) in the presence of IAA (0.1 mg l−1) significantly increased F0, but decreased FV/FM and ΦII. 相似文献
18.
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
19.
M. E. Estrada-Zúñiga F. Cruz-Sosa M. Rodríguez-Monroy J. R. Verde-Calvo E. J. Vernon-Carter 《Plant Cell, Tissue and Organ Culture》2009,97(1):39-47
Plant tissue cultures represent a potential source for producing secondary metabolites. In this work, Buddleja cordata tissue cultures were established in order to produce phenylpropanoids (verbascoside, linarin and hydroxycinnamic acids),
as these metabolites are credited with therapeutic properties. Highest callus induction (76.4–84.3%) was obtained in five
treatments containing 2,4-Dichlorophenoxyacetic acid (2,4-d: 0.45–9.05 μM) with Kinetin (KIN: 2.32, 4.65 μM), whereas highest root induction (79.6%) corresponded to the α-Naphthaleneacetic
acid (9.05 μM) with KIN (2.32 μM) treatment. Verbascoside was the major phenylpropanoid produced in in vitro cultures (root,
white and green callus) [66.24–86.26 mg g−1 dry weight (DW)], while linarin and hydroxycinnamic acid production was low (0.95–3.01 mg g−1 DW). Verbascoside and linarin production were improved in cell suspension culture (116 mg g−1 DW and 8.12 mg g−1 DW, respectively). 相似文献
20.
Ehsan Ullah Khan Xing-Zheng Fu Ji-Hong Liu 《Plant Cell, Tissue and Organ Culture》2012,109(2):383-390
In this study, attempts were made to develop a protocol for regeneration of transgenic plants via Agrobacterium tumefaciens-mediated transformation of leaf segments from ‘Valencia’ sweet orange (Citrus sinensis L. Osbeck) using gfp (green fluorescence protein) as a vital marker. Sensitivity of the leaf segments regeneration to kanamycin was evaluated,
which showed that 50 mg l−1 was the best among the tested concentrations. In addition, factors affecting the frequency of transient gfp expression were optimized, including leaf age, Agrobacterium concentration, infection time, and co-cultivation period. Adventitious shoots regenerated on medium containing Murashige
and Tucker basal medium plus 0.1 mg l−1 α-naphthaleneacetic acid (NAA), 0.5 mg l−1 6-benzyladenine (BA) and 0.5 mg l−1 kinetin (KT). The leaf segments from 3-month-old in vitro seedlings, Agrobacterium concentration at OD600 of 0.6, 10-min immersion, and co-cultivation for 3 days yielded the highest frequency of transient gfp expression, shoots regeneration response and transformation efficiency. By applying these optimized parameters we recovered
independent transformed plants at the transformation efficiency of 23.33% on selection medium (MT salts augmented with 0.5 mg l−1 BA, 0.5 mg l−1 KT, 0.1 mg l−1 NAA, 50 mg l−1 kanamycin and 250 mg l−1 cefotaxime). Expression of gfp in the leaf segments and regenerated shoots was confirmed using fluorescence microscope. Polymerase chain reaction (PCR)
analysis using gfp and nptII gene-specific primers further confirmed the integration of the transgene in the independent transgenic plants. The transformation
methodology described here may pave the way for generating transgenic plants using leaf segments as explants. 相似文献