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1.
Talita Aparecida Balzon Zanderluce Gomes Luis Jonny Everson Scherwinski-Pereira 《In vitro cellular & developmental biology. Plant》2013,49(1):41-50
We developed an efficient and simple system for inducing somatic embryogenesis and regenerating plantlets from mature zygotic embryos of oil palm. Embryogenic calli were induced from mature zygotic embryos of oil palm on modified Murashige and Skoog medium with 2,4-dichlorophenoxyacetic acid or picloram, alone or in combination with activated charcoal. The greatest frequency of embryogenic callus induction (97.5%) was obtained by culturing mature zygotic embryos on callus induction medium with 450 μM picloram and 2.5 g?L?1 activated charcoal. Embryogenic calli proliferated on a medium with a reduced concentration of picloram. Embryogenic calli were then subcultured on a medium supplemented with 12.3 μM 2-isopentenyladenine and 0.54 μM naphthaleneacetic acid, with subcultures at 4-wk intervals. Somatic embryos were regenerated on a medium with Murashige and Skoog macro- and micronutrients at half-strength concentrations supplemented with 20 g?L?1 sucrose, 2.5 g?L?1 activated charcoal, and 2.5 g?L?1 Phytagel. Detailed histological analysis revealed that somatic embryogenesis followed an indirect pathway. Primary calli were observed after 4–6 wk of culture and progressed to embryogenic calli at 12 wk. Embryogenic cells exhibited dense protoplasm, a high nucleoplasmic ratio, and small starch grains. Proembryos, which seemed to have a multicellular origin, formed after 16–20 wk of culture and successive cell divisions. Differentiated somatic embryos had a haustorium, a plumule, and the first and second foliar sheaths. In differentiated embryos, the radicular protrusion was not apparent because it generally does not appear until after the first true leaves emerge. 相似文献
2.
Embryogenic calli of Dioscorea bulbifera L. were successfully cryopreserved using an encapsulation-vitrification method. Embryogenic calli were cooled at 6°C for
5 days on solid MS medium (Murashige and Skoog 1962) containing 2 mg L−1 Kinetin (Kn), 0.5 mg L−1 α-naphthalene acetic acid (NAA) and 0.5 mg L−1 2,4-dichlorophenoxy-acetic acid (2,4-D). These were prior precultured on liquid basal MS medium enriched with 0.75 M sucrose
at 25 ± 1°C for 7 days. Embryogenic calli were osmoprotected with a mixture of 2 M glycerol and 1 M sucrose for 80 min at
25°C and dropped in a 0.1 M CaCl2 solution containing 0.4 M sucrose at 25 ± 1°C. After 15 min of polymerization, Ca-alginate beads (about 4 mm in diameter)
were dehydrated for 150 min at 0°C in a PVS2 solution [30% glycerol, 15% ethylene glycol, and 15% dimethyl sulfoxide (w/v)] containing 0.5 M sucrose. The encapsulated
embryogenic calli were then plunged directly into LN (liquid nitrogen) for 1 h. After rapid thawing in a water bath (37°C;
2 min), the beads were washed 3 times at 10-min intervals in liquid basal MS medium containing 1.2 M sucrose. Following thawing,
the embryogenic calli were transferred to fresh solid basal MS media supplemented with Kn 2 mg L−1, 0.09 M sucrose and 0.75% (w/v) agar (embryoid induction medium) and cultured under light conditions of 12-h photoperiod
with a light intensity of 36 μmol m−2 s−1 provided by white cool fluorescent tubes after a 2-day dark period at 25 ± 1°C. After 30 days, the embryoids developed from
embryogenic calli were transferred to fresh solid basal MS media supplemented with Kn 2 mg L−1, NAA 0.5 mg L−1, 3% (w/v) sucrose and 0.75% (w/v) agar (regeneration medium). After 60 days, the embryogenic calli developed normal shoots
and roots. No morphological abnormalities were observed after plating on the regeneration medium. The survival rate of encapsulated
vitrified embryogenic callus reached over 70%. This encapsulation-vitrification method appears promising as a routine and
simple method for the cryopreservation of Dioscorea bulbifera embryogenic callus. 相似文献
3.
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
4.
Dioscorea fordii Prain et Burk., a member of the family Dioscoreaceae, is an important tuberous food in China owing to its edible and medicinal
functions. However, the lack of healthy planting material has restricted its production. The present study was an attempt
to develop a protocol for in vitro propagation of D. fordii. In an initial two by two (22) factorial experiment, the effects of culture system and activated charcoal have been observed for axillary shoot proliferation
and tuberization of in vitro plantlets. Shoot length, frequency of proliferation, fresh weight and dry weight of shoots, frequency
of tuberization and mean number of tubers per plantlet (NTPs) were significantly (P ≤ 0.05) greater in liquid medium compared to semi-solid media. Secondly, an orthogonal experimental design [L9 (34)] was used to investigate the effects of the ratio of naphthalene acetic acid (NAA) to 6-benzyladenine (BA) (NAA/BA), paclobutrazol,
methyl jasmonate and sucrose concentration on tuberization. Sucrose concentration had the record effect on frequency of tuberization,
NTPs and frequency of proliferation. The preferred medium for axillary shoot proliferation and tuberization of D. fordii found to be MS basal medium (Murashige and Skoog in Physiol Plant 15:473–479, 1962) supplemented with 1.0 mg l−1 BA, 0.1 mg l−1 NAA, 30 g l−1 sucrose and 1.5 g l−1 AC in liquid culture. 相似文献
5.
Smita Srivastava Ashok Kumar Srivastava 《In vitro cellular & developmental biology. Plant》2012,48(1):73-84
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
6.
Yohana de Oliveira Fernanda Pinto André Luís Lopes da Silva Ivan Guedes Luiz Antonio Biasi Marguerite Quoirin 《In vitro cellular & developmental biology. Plant》2010,46(2):192-197
Melaleuca alternifolia is cultivated for the production of an essential oil useful in the cosmetic and pharmaceutical industries. Despite the economic
importance of this species, there is little knowledge about its in vitro propagation. The aim of this study was to establish an efficient protocol for micropropagation of M. alternifolia. With the goal of in vitro multiplication by axillary shoot proliferation, both solid and liquid MS and WPM media were tested with supplementation with
BA at 0, 0.55, 1.11, 2.22, 3.33, and 4.44 μM. The best result for shoot multiplication was obtained when either 0.55 μM BA
was added into solid MS medium or 1.11 μM BA was added into liquid MS medium, with 5.6 and 11.8 shoots per explant generated,
respectively. On solid or liquid WPM medium supplemented with 0.55 μM BA, the proliferation rates were 5.5 and 4.7, respectively.
Three auxins (NAA, IAA, and IBA) were tested at 0.53 and 2.64 μM during the rooting stage. Several sucrose concentrations
(15, 30, and 45 g L−1) were compared to a sucrose-free medium. Rooting performances on four culture media were then compared: MS, half-strength
MS (MS/2), MS + activated charcoal (AC), and MS/2 + AC. The results showed that auxin addition to culture medium is not necessary
for in vitro rooting. Rooted microcuttings from different culture media were acclimatized in a greenhouse, and the survival percentage was evaluated.
All shoots cultured in an auxin-free MS medium supplemented with sucrose (30 g L−1) produced roots, and all plants survived during acclimatization. Activated charcoal added in rooting medium reduced rooting
rates. 相似文献
7.
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
8.
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
9.
Jonny Everson Scherwinski-Pereira Rodrigo da Silva Guedes Ricardo Alexandre da Silva Paulo César Poeta FerminoJr. Zanderluce Gomes Luis Elínea de Oliveira Freitas 《Plant Cell, Tissue and Organ Culture》2012,109(3):501-508
An efficient and simple system for inducing somatic embryogenesis and regenerating plantlets from immature zygotic embryos of açaí palm (Euterpe oleracea) has been developed. Embryogenic calli (ECs) were induced from immature zygotic embryos of açaí palm on Murashige and Skoog (MS) modified medium with 2,4-dichlorophenoxyacetic acid and picloram. Embryogenic frequency was dependent on auxin type and concentration. The optimal concentration of picloram for the high-frequency induction of embryogenic calli (72%) was 225 μM. ECs were then subcultured on a differentiation and maturation medium composed of MS modified medium with 2-isopentenyladenine and naphthaleneacetic acid with subcultures at 4-week intervals. SEs were converted to plants on MS modified medium with half-strength macro- and micronutrients, 20 g l?1 sucrose, and 2.5 g l?1 activated charcoal and gelled with 2.5 g l?1 Phytagel. Detailed morpho anatomical changes during the different stages of somatic embryogenesis were characterized. The development of SEs was asynchronous, and ontogenic studies confirmed that the initial cell divisions occur in the epidermal and subepidermal regions of the zygotic embryos. Broad base attachment of SEs to the epidermis indicates the presence of a suspensor. 相似文献
10.
Mashitha Pise Jaishree Rudra Sunita Bundale Deovrat Begde Nandita Nashikkar Avinash Upadhyay 《In vitro cellular & developmental biology. Plant》2012,48(1):85-91
Asparagus racemosus is an important monocot medicinal plant that is in great demand for its steroidal saponins called shatavarins. This study
was initiated to optimize the conditions for production of shatavarins in cell cultures of A. racemosus in a modified Murashige and Skoog (MS) medium supplemented with six different combinations of growth regulators. Biomass
accumulation was correlated with saponin production over a 30-d culture cycle. Biomass and saponin accumulation patterns were
dependent on combinations of growth regulators and the pH of the medium. Maximum levels of saponin and biomass accumulation
were recorded on day 25 of the culture cycle within a pH range of 3.4 to 5.6. Total saponin produced by the in vitro cultures was 20-fold higher than amounts produced by cultivated plants. Saponin accumulation was not a biomass-associated
phenomenon; cultures which showed the highest biomass accumulation were not the highest saponin accumulators. Maximum biomass
(28.30 ± 0.29 g l−1) and maximum levels of shatavarin IV(11.48 ± 0.61 mg g−1) accumulation was found using a medium containing 2.0 mg l−1 2,4-D, 2 g l−1 casein hydrolysate and 0.005% pectinase. The highest levels of sarsapogenin, secreted and intracellular (4.02 ± 0.09 mg g−1), accumulated using a medium containing 1.0 mg l−1 NAA, 1.0 mg l−1 2,4-D, 0.5 mg l−1 BAP, 2 g l−1 casein hydrolysate and 0.005% pectinase, after 25 d. Shatavarins were secreted into the medium and can be isolated easily
for further purification. 相似文献
11.
I. A. Montalbán N. De Diego E. Aguirre Igartua A. Setién P. Moncaleán 《Plant biotechnology reports》2011,5(2):177-186
This study describes for the first time in Pinus genus a plant regeneration system via a combined pathway of somatic embryogenesis and organogenesis from immature seeds of
radiata pine. Somatic embryos were obtained from embryogenic line 2162 of Pinus radiata D. Don on EDM basal medium containing 60 μM ABA and 6% sucrose. The explants used for organogenesis experiments were either
freshly collected somatic embryos or somatic embryos germinated for 1 week. Germination medium was half-strength LP medium,
supplemented with 0.2% activated charcoal. Different induction periods and BA concentrations were assayed for shoot induction.
After induction treatments, explants were elongated on the same medium used for germination stage. Rooting medium was quarter-strength
LP medium supplemented with three different auxin treatments: 1.5 mg L−1 1-naphthalene acetic acid (NAA), 1.5 mg L−1 indole-3-butyric acid (IBA) and 1 mg L−1 IBA with 0.5 mg L−1 NAA (MIX). The effect of the photon flux (120 mmol m−2 s−1 and darkness) in the first week of the explants in the rooting media was also tested. This methodology could offer an alternative
to overcome some problems associated with somatic embryogenesis such as the seasonality of embryogenic tissue (ET) initiation
or a low embryo production from the ET, a particularly important issue in the case of genetically transformed ETs. 相似文献
12.
Candida peltata NRRL Y-6888 to ferment xylose to xylitol was evaluated under different fermentation conditions such as pH, temperature, aeration,
substrate concentration and in the presence of glucose, arabinose, ethanol, methanol and organic acids. Maximum xylitol yield
of 0.56 g g−1 xylose was obtained when the yeast was cultivated at pH 6.0, 28°C and 200 rpm on 50 g L−1 xylose. The yeast produced ethanol (0.41 g g−1 in 40 h) from glucose (50 g L−1) and arabitol (0.55 g g−1 in 87 h) from arabinose (50 g L−1). It preferentially utilized glucose > xylose > arabinose from mixed substrates. Glucose (10 g L−1), ethanol (7.5 g L−1) and acetate (5 g L−1) inhibited xylitol production by 61, 84 and 68%, respectively. Arabinose (10 g L−1) had no inhibitory effect on xylitol production.
Received 24 December 1998/ Accepted in revised form 18 March 1999 相似文献
13.
D. A. Steinmacher G. C. Cangahuala-Inocente C. R. Clement M. P. Guerra 《In vitro cellular & developmental biology. Plant》2007,43(2):124-132
The factors affecting the induction and development of somatic embryos and plantlet acclimatization of peach palm (Bactris gasipaes Kunth) were evaluated to establish an efficient regenerative protocol based on somatic embryogenesis. Mature zygotic embryos
were cultured in Murashige and Skoog (MS) medium supplemented with 0–40 μM of picloram (4-amino-3,5,6-trichloropicolinic acid)
and 0 or 5 μM of 2-isopentyladenine (6-dimethylaminopurine) (2-iP). After 5 mo. in culture embryogenic callus arose from primary
calli. Picloram (10 μM) was effective in inducing embryogenic calli in 9.8% of the explants. The use of 1 μM of AgNO3 enhanced embryogenic competence. Embryogenic calli showed an organized structure, a globular aspect, and were white to yellowish
in color. Histological analyses showed that cell proliferation arose from subepidermal cells adjacent to vascular bundles,
resulting in primary callus formed by a meristematic zone from which somatic embryos arose. Protein profile analyses revealed
two high molecular mass bands in these embryogenic calli, but not in other tissues. Embryogenic calli were transferred to
a culture medium containing 40 μM of 2,4-dichlorophenoxyacetic acid, 10 μM of 2-iP, plus 1 g l−1 of glutamine, hydrolyzed 0.5 g l−1 casein, and activated 1.5 g l−1 of charcoal. Morphogenetic responses achieved in this medium were the development of somatic embryos, rooting, and loss of
embryogenic capacity. Somatic embryos were converted to plantlets on MS medium plus 24.6 μM of 2-iP and 0.44 μM of naphthalene
acetic acid. Plantlets were maintained in MS medium with activated charcoal (1.5 g l−1) until they were 6 cm tall, and then acclimatized. After 16 wk, 84.2 ± 6.4% survival was observed.
M. P. Guerra and C. R. Clement are Fellows of the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Brasília,
DF. 相似文献
14.
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
15.
Ben Dhiab Rym Ghenim Nejeh Trabelsi Lamia Yahia Ali Challouf Rafika Ghozzi Khemissa Ammar Jihene Omrane Hela Ben Ouada Hatem 《Journal of applied phycology》2010,22(6):745-752
Combined effect of light intensity and glucose concentration on Arthrospira platensis growth and photosynthetic response was evaluated using a 32 factorial design. This design was carried out with light levels of 50, 100, and 150 μmol photons m−2 s−1 and glucose concentrations of 0.5, 1.5, and 2.5 g L−1. Results from the response surface methodology were that the highest level of light intensity and glucose concentration improved
biomass (1.33 g L−1), maximum specific growth rate (0.49 day−1), and net photosynthetic rate (139.89 μmol O2 mg Chl−1 h−1). Furthermore, the interaction of both factors showed that at low light, glucose had a low effect on maximum biomass and
maximal net photosynthetic rate. However, at the highest light levels, the effect of glucose was more sensitive and the increase
of glucose concentration increased the levels of all responses. The rates of the instantaneous relative growth, net photosynthesis,
and dark respiration of growth cultures showed two different phases in mixotrophic condition. The first was distinguished
by the preponderance of the photoautotrophic mode; the second was based mainly on photoheterotrophy. 相似文献
16.
Exopolysaccharide (EPS) production was compared among three strains of lactobacilli. Lactobacillus rhamnosus strain 9595M can be classified among the highest EPS-producing strains of lactic acid bacteria reported to date with a maximum
EPS production of 1275 mg L−1. Under controlled pH, no significant differences in the quantity of EPS produced could be detected between carbon source
(glucose or lactose) or fermentation temperature (32 or 37°C). In milk, strains ATCC 9595M and R produced more than 280 mg L−1 EPS whereas strain Type V produced less than 80 mg L−1 EPS. Journal of Industrial Microbiology & Biotechnology (2000) 24, 251–255.
Received 10 September 1999/ Accepted in revised form 22 December 1999 相似文献
17.
Delta-endotoxin production by a strain of Bacillus thuringiensis subsp kurstakion complex media based on crude gruel and fish meal was investigated. High proteolytic activities were concomitantly produced
with the bioinsecticide. In such complex media, the repressive regulation due to readily consumed carbon sources was partially
overcome. In order to improve substrate assimilation, 0.5 g L−1 sodium chloride and 0.1% Tween-80 were supplemented to the production medium, increasing delta-endotoxin yields when using
gruel concentrations below 59 g L−1. At and beyond 75 g L−1 gruel, delta-endotoxin yields were not affected in the presence of 0.5 g L−1 NaCl and 0.1% Tween-80, but proteolytic activity yields were remarkably reduced. Thus, the use of sodium chloride and Tween-80
allowed reduction of the initial gruel concentration to 42 g L−1 for the production of 3350 mg L−1 delta-endotoxin, while it was only 3800 mg L−1 with 92 g L−1 gruel. Moreover, similar to 0.5 g L−1 NaCl and 0.1% Tween-80, the use of 10 g L−1 sodium acetate significantly improved delta-endotoxin production and also reduced the proteolytic activity to 250 U ml−1.
Received 05 November 1998/ Accepted in revised form 19 August 1999 相似文献
18.
N. Selvaraj S. Kasthurirengan A. Vasudevan M. Manickavasagam C. W. Choi A. Ganapathi 《In vitro cellular & developmental biology. Plant》2010,46(4):329-337
Efficient Agrobacterium tumefaciens-mediated transformation and a higher recovery of transformed plants of cucumber cv. Poinsett76 were achieved via direct organogenesis
from cotyledon explants. Stable transformants were obtained by inoculating explants with A. tumefaciens strains EHA105 or LBA4404, both harboring the binary vector pME508, which contains the neomycin phosphotransferase II (nptII) and phosphinothricin resistance genes (bar) conferring resistance to kanamycin and PPT, respectively, as selectable markers and the sgfp-tyg gene for the green fluorescent protein (GFP) as a visual marker driven by the constitutive CaMV35S promoter in the presence
of acetosyringone (50 μM). Transformed shoots were obtained on MS Murashige and Skoog (Plant Physiol. 15: 473–497, 1962) medium supplemented with 1 mg L−1 benzyladenine (BA), 20 mg L−1
l-glutamine and 2 mg L−1 phosphinothricin (PPT) or 100 mg L−1 kanamycin. The regenerated shoots were examined in vivo using a hand-held long wave UV lamp for GFP expression. The GFP screening helped identify escapes and chimeric shoots at
regular intervals to increase the growth of transformed shoots on cotyledon explants. Elongation and rooting of putative transformants
were achieved on PPT (2 mg L−1) containing MS media with 0.5 mg L−1 gibberellic acid (GA3) and 0.6 mg L−1 indole butyric acid (IBA), respectively. PCR and Southern analyses confirmed the integration of the sgfp gene into the genome of T0 and the progenies. T1 segregation of transgenic progeny exhibited Mendelian inheritance of the transgene. The use of EHA105 resulted in 21% transformation
efficiency compared to 8.5% when LBA4404 was used. This higher rate was greatly facilitated by PPT selection coupled with
effective screening of transformants for GFP expression, thus making the protocol highly useful for the recovery of a higher
number of transgenic cucumber plants. 相似文献
19.
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
20.
Repetitive Somatic Embryogenesis of Ocotea catharinensis Mez. (Lauraceae): Effect of Somatic Embryo Developmental Stage and Dehydration 总被引:3,自引:1,他引:2
Claudete Santa Catarina Alessandra dos Santos Olmedo Geraldine de Andrade Meyer Jonice Macedo Wagner de Amorim Ana Maria Viana 《Plant Cell, Tissue and Organ Culture》2004,78(1):55-62
Repetitive embryogenesis of Ocotea catharinensis from globular/early cotyledonary somatic embryos was successfully supported by WPM supplemented with 22.7 g l−1 sorbitol, 20 g l−1 sucrose, 400 mg l−1 glutamine and 2 g l−1 Phytagel. The best medium to induce repetitive embryogenesis in cotyledonary somatic embryos was half strength WPM supplemented
with 20 g l−1 sucrose, 400 mg l−1 glutamine, 1.5 g l−1 activated charcoal and 2 g l−1 Phytagel. The mature somatic embryos gradually air dehydrated showed repetitive embryogenesis after subculture on half strength
B5 medium supplemented with 20 g l− sucrose, 20 g l−1 Phytagel, 1.5 g l−1 activated charcoal, 115.6 μM gibberellic acid and 214.8 μM naphthaleneacetic acid. The early cotyledonary, cotyledonary and
mature somatic embryos tolerated respectively 95, 86 and 54% fresh weight losses without losing their repetitive embryogenesis
potential. Cotyledonary and mature somatic embryos gradually air dehydrated in sealed Petri dishes showed 40–41% repetitive
embryogenesis respectively after 20 days and 12 weeks desiccation storage. Repetitive embryogenesis in cotyledonary somatic
embryos was significantly stimulated by chemical dehydration with 0.5 M sorbitol and 56% repetitive embryogenesis was achieved
even after exposure to 2 M sorbitol for 24 h. The cotyledonary somatic embryos when alginate-encapsulated showed 47% repetitive
embryogenesis even after chemical dehydration in 1.5 M sorbitol for 4 days followed by 1 h air dehydration, but failed to
survive to the same dehydration conditions without encapsulation. The optimized repetitive embryogenesis and desiccation protocols
offer the possibility to use in vitro techniques for continuous reliable somatic embryo production and short term germplasm storage. 相似文献