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1.
The recombinant β-carotene 15,15′-monooxygenase from chicken liver was purified as a single 60 kDa band by His-Trap HP and Resource Q chromatography.
It had a molecular mass of 240 kDa by gel filtration indicating the native form to be tetramer. The enzyme converted β-carotene under maximal conditions (pH 8.0 and 37°C) with a k
cat of 1.65 min−1 and a K
m of 26 μM and its conversion yield of β-carotene to retinal was 120% (mol mol−1). The enzyme displayed catalytic efficiency and conversion yield for β-carotene, β-cryptoxanthin, β-apo-8′-carotenal, β-apo-4′-carotenal, α-carotene and γ-carotene in decreasing order but not for zeaxanthin, lutein, β-apo-12′-carotenal and lycopene, suggesting that the presence of one unsubstituted β-ionone ring in a substrate with a molecular weight greater than C30 seems to be essential for enzyme activity. 相似文献
2.
3.
Kim YS Kim NH Kim HJ Lee JK Kim SW Oh DK 《Applied microbiology and biotechnology》2007,76(6):1339-1345
The gene encoding β-carotene 15,15′-monooxygenase from Mus musculus (house mouse), which cleaves β-carotene into two molecules of retinal, was cloned and expressed in Escherichia coli. The expressed enzyme was purified by His-tag affinity and resource Q ion exchange chromatography columns to a final specific
activity of 0.51 U mg−1. The optimum pH, temperature, substrate and detergent concentrations, and enzyme amount for effective retinal production
were determined to be 9.0, 37°C, 200 mg l−1 β-carotene, 5% (w/v) Tween 40, and 0.2 U ml−1 enzyme, respectively. Under optimum conditions, the recombinant enzyme produced 72 mg l−1 retinal in a 15-h reaction time, with a conversion yield of 36% (w/w). The specific activity of the purified enzyme and retinal
production obtained in the present study were the highest results ever reported. 相似文献
4.
To produce recombinant β-carotene in vitro, synthetic operons encoding genes governing its biosynthesis were engineered into Escherichia coli. Constructs harboring these operons were introduced into either a high-copy or low-copy cloning vector. β-Carotene production from these recombinant E. coli cells was either constitutive or inducible depending upon plasmid copy number. The most efficient β-carotene production was with the low-copy based vector. The process was increased incrementally from a 5 l to a 50 l fermentor and finally into a 300 l fermentor. The maximal β-carotene yields achieved using the 50 l and 300 l fermentor were 390 mg l−1 and 240 mg l−1, respectively, with overall productivities of 7.8 mg l−1 h−1 and 4.8 mg l−1 h−1. 相似文献
5.
Fungi produce and accumulate various carotenoids. Mycelia of the ZygomyceteBlakeslea trispora contained β-carotene and its precursors γ-carotene and lycopene. When strains of opposite sex grew together, the β-carotene
concentration increased fourfold, that of γ-carotene remained unchanged, and other intermediates practically disappeared.
The inhibitors nicotine, 2-(4-chlorophenylthio)-triethylamine, α-picoline, and imidazole increased the concentrations of lycopene
and γ-carotene and decreased those of β-carotene. From our quantitative results, we conclude thatBlakeslea has two pathways for lycopene metabolism, of which other fungi have only one or the other. The main one, two cyclizations
from lycopene to β-carotene, is carried out by an enzyme dimer, is stimulated by sexual interaction, and is sensitive to the
inhibitors. The other pathway, a cyclization to γ-carotene is not affected by mating or the inhibitors. 相似文献
6.
Summary In the present study Dunaliella sp. that could grow in the Johnson medium was isolated from hypersaline Lake Tuz and its β-carotene production was studied in a batch system, in order to determine the optimal conditions required for the highest β-carotene accumulation. In the experiments with light intensity, the cell numbers and β-carotene content were maximum at pH 9, with 20% of NaCl concentration and 48 kerg cm−2 s−1 light intensity. At this light intensity, the β-carotene content of Dunaliella sp. ranged between 0.177 and 1.095 mg/ml for the culture broth and 0.119 to 0.261 ng/cell on a per cell basis under the nitrogen limitation. At the end of the experiments, the maximum β-carotene accumulation and the cell number were obtained at pH 7, 5 mM NaNO3 and 20% NaCl concentrations as 0.261 ng/cell, 4.2×106 cell/ml, respectively. 相似文献
7.
Enrique A. Iturriaga Antonio Velayos Arturo P. Eslava 《Biotechnology and Bioprocess Engineering》2000,5(4):263-274
Carotenoids are widely distributed natural pigments which are in an increasing demand by the market, due to their applications
in the human food, animal feed, cosmetics, and pharmaceutical industries. Although more than 600 carotenoids have been identified
in nature, only a few are industrially important (β-carotene, astaxanthin, lutein or lycopene). To date chemical processes
manufacture most of the carotenoid production, but the interest for carotenoids of biological origin is growing since there
is an increased public concern over the safety of artificial food colorants. Although much interest and effort has been devoted
to the use of biological sources for industrially important carotenoids, only the production of biological β-carotene and
astaxanthin has been reported. Among fungi, several Mucorales strains, particularlyBlakeslea trispora, have been used to develop fermentation process for the production of β-carotene on almost competitive cost-price levels.
Similarly, the basidiomycetous yeastXanthophyllomyces dendrorhous (the perfect state ofPhaffia rhodozyma), has been proposed as a promising source of astaxanthin. This paper focuses on recent findings on the fungal pathways for
carotenoid production, especially the structure and function of the genes involved in the biosynthesis of carotenoids in the
Mucorales. An outlook of the possibilities of an increased industrial production of carotenoids, based on metabolic engineering
of fungi for carotenoid content and composition, is also discussed. 相似文献
8.
Emmanouil H. Papaioannou Nikolaos G. Stoforos Maria Liakopoulou-Kyriakides 《World journal of microbiology & biotechnology》2011,27(4):851-858
Blakeslea trispora produces carotenoids mixtures consisting mainly of lycopene, γ-carotene and β-carotene, together with trace amounts of other
carotenoid precursors. The yield of these carotenoids and their composition are greatly affected by culture substrate. The
scavenging capacity of carotenoids extract from cultures of B. trispora growing in various substrates was estimated using the 2,2-diphenyl-1-picrylhydrazyl method. Fractions enriched in β-carotene,
γ-carotene and lycopene, obtained after column chromatography in alumina basic II, were also examined. Substrates containing
starch and oils mixture, Ni2+, and that with pantothenic acid presented higher antioxidant activity. An increase in the antioxidant activity of the crude
carotenoid extract compared to that of the isolated fractions enriched in β-carotene, γ-carotene and lycopene respectively,
observed in most samples, indicated a possible synergistic effect. The results are of interest and by expanding this study
to more substrates and other microorganisms- producing antioxidants, a formulation of extract with high free radical scavenging
potential could be produced. 相似文献
9.
V. M. Hanchinal S. A. Survase S. K. Sawant U. S. Annapure 《Plant Cell, Tissue and Organ Culture》2008,93(2):123-132
Plants are a valuable source of a vast array of chemical compounds including fragrances, flavours, food additives, colours,
natural sweeteners, industrial feedstocks, anti-microbials and pharmaceuticals. The present study reports on application of
Response Surface Methodology (RSM) in media optimization for suspension culture for the production of β-carotene. Growth kinetics
of carrot cells in suspension culture has been carried out to understand the relationship between growth and β-carotene formation.
The maximum production of β-carotene obtained using the optimized medium was 13.614 μg/g dry weight cell mass. The μ (specific growth rate) and t
d
(doubling time) were found to be higher for 20 g DW/l inoculum size. 相似文献
10.
Two-year-old rosemary (Rosmarinus officinalis L.) plants were subjected to severe stress by exposure to prolonged drought during a Mediterranean summer. Severely stressed
plants recovered completely after the autumn rainfalls although the relative water content remained below 35% for 3 months
and the chlorophyll content of leaves was reduced by up to 85% during the drought. In severe stress: (i) α-tocopherol increased
9-fold per g dry weight and 20-fold per unit of chlorophyll; (ii) lutein and β-carotene contents decreased on a dry-weight
basis, but an 80% increase in lutein and constant levels of β-carotene were observed on a chlorophyll basis; (iii) there were
transient and sustained increases in the de-epoxidation state of the xanthophyll cycle; and (iv) the highly oxidised abietane
diterpene isorosmanol increased 8-fold as a result of the oxidation of carnosic acid. With the autumn rainfalls, water status,
α-tocopherol and violaxanthin recovered first and the levels of photosynthetic pigments and abietane diterpenes increased
later. The photoprotection conferred by the xanthophyll cycle and the antioxidant function of tocopherols, lutein and diterpenes
may help to avoid irreversible damage in severe drought, making possible the recovery of functional membranes after the autumn
rainfalls. Besides, chlorophyll loss reduces the amount of photons absorbed by leaves, which enhances the photoprotective
and antioxidant capacity of leaves per amount of photons absorbed, since the ratios of xanthophylls, α-tocopherol and abietane
diterpenes to chlorophyll increase.
Received: 12 July 1999 / Accepted: 25 November 1999 相似文献
11.
Tozzi R Mulinacci N Storlikken K Pasquali I Vincieri FF Bettini R 《AAPS PharmSciTech》2008,9(2):693-700
The purpose of this research was to preliminary assess the suitability of a new method for the preparation of a solid formulation
in form of powder composed by β-cyclodextrin and the supercritical extract of Rosa canina hips. The method implies the extraction of carotenoids, in particular β-carotene, from freeze dried fruits of R. canina with supercritical CO2 at 70 °C and 300 bar, in the presence of varying quantity of ethanol as entrainer. The obtained supercritical solution is
then expanded at ambient conditions into an aqueous solution of β-cyclodextrin to favour the interaction between β-cyclodextrin
and the lipophilic components of the extract. β-carotene solubility (mole fraction) in supercritical CO2 or in supercritical CO2/ethanol mixtures were in the order of 1 10−7. The β-carotene extracted from R. canina fruits (nearly 10 μg/g of dry matrix), interacts almost quantitatively with β-cyclodextrin affording a solid phase, which
presents a low apparent solubility in water. Finally the interaction with β-cyclodextrin results in a higher concentration
of the β-carotene trans- form relative to the cis- form in the extracted product when collected in an aqueous solution of β-cyclodextrin with respect to the extract in n-hexane. 相似文献
12.
In animals, β-carotene 15,15′-monooxygenase (BCMO) is the key enzyme involved in the metabolism of plant β-carotene to retinal.
In the present study, we utilized β-carotene-producing Escherichia coli to screen for mutants with higher BCMO activity which was monitored by color changes derived from β-carotene cleavage. Recombinant
wild-type and T381L mutant BCMO proteins were purified to near homogeneity in E. coli, and their enzymatic activities were determined by HPLC analysis. The catalytic efficiency for β-carotene and retinal production
of the mutant were 1.5-fold and 1.7-fold higher than those of wild-type, respectively. Further BCMO function in mammalian
cells was analyzed by a retinoic acid receptor reporter assay, which responds to the metabolic conversion of β-carotene to
retinoic acid in vivo. Overall, these tools can be used to screen more active BCMO for the industrial and pharmacological
purpose of retinal production from β-carotene. 相似文献
13.
Cheng Q 《Journal of industrial microbiology & biotechnology》2006,33(7):552-559
Many new carotenoid synthesis genes have recently been identified through genomic sequencing or functional cloning. Some of them exhibit novel structures and/or novel functions. This review describes such examples in the families of lycopene β-cyclases, putative homologues of phytoene dehydrogenases and new carotenoid hydroxylases. Both the functionally novel lycopene β-monocyclases and structurally novel fusion-type of lycopene β-cyclases were described. Another newly discovered sequence of lycopene β-cyclase described might represent a new class of lycopene β-cyclases previously not identified in several cyanobacteria. Three examples of putative homologues of phytoene dehydrogenases were described, however, they were confirmed to encode different and/or new functions such as β-carotene ketolase, 4,4′-diapolycopene oxygenase or prolycopene isomerase. Two new carotenoid hydroxylase genes were described that encoded the new function of 2,2′-β-ionone ring hydroxylase or 3,3′-isorenieratene hydroxylase. Phylogenetic analysis of these genes shed light on their possible evolutionary origins. These new genes also provide tools for synthesis of novel and desirable carotenoids by genetic engineering. 相似文献
14.
Juan Luis Gómez-Pinchetti Ziyadin Ramazanov Agustín Fontes Guillermo García-Reina 《Journal of applied phycology》1992,4(1):11-15
Photosynthetic characteristics of Dunaliella salina with high (red form) and low β-carotene (green form) concentrations were studied. D. salina growing in brine saltworks exhibited a high level of β-carotene (15 pg cell−1). The rate of oxygen evolution as a function of irradiance was higher in the red than in the green form (on chlorophyll basis).
Photosynthetic inhibition of the green form was observed above 500 μmol m−2 s−1. The red form appeared more resistant to high irradiance and no inhibition in O2 evolution was observed up 2000 μmol m−2 s−1. However, when these results are expressed on a cell number basis the rate of oxygen evolution was significantly higher in
the green form.
Carbonic anhydrase (CA) activity (total, soluble, membrane bound) was found in red and green forms. CA was higher in the red
form on a chlorophyll basis, but lower if expressed on a protein basis. The light dependent rate of oxygen evolution and photoinhibition
depends on the concentration of β-carotene in D. salina cells. 相似文献
15.
16.
Parkhi V Rai M Tan J Oliva N Rehana S Bandyopadhyay A Torrizo L Ghole V Datta K Datta SK 《Molecular genetics and genomics : MGG》2005,274(4):325-336
A single Agrobacterium strain harbouring two binary plasmids was successfully used for the first time to develop a marker-free transgenic rice of
improved nutritional value. Sixty-eight T0 co-transformants were obtained in three indica rice cultivars—two popular high-yielding Bangladeshi varieties (BR28 and BR29), and one high-iron rice cultivar (IR68144).
Marker-free lines were obtained from 14 out of 24 selected co-transformants screened in the T1 generation. The accumulation of total carotenoids in polished T2 rice seeds of the primary transgenic VPBR29-17-37 reached levels of up to 3.0 μg/g, with the level of β-carotene reaching
1.8 μg/g. In the cultivars BR28 and IR68144, total carotenoid levels in the transformants reached 2.0 μg/g of polished rice
seeds. The levels of lutein and other carotenoids in the seeds were also significantly enhanced. T1 plants obtained from primary transgenics with simple gene-integration patterns tended to have a lower carotenoid content
than the original parental lines. This study describes the development of marker-free transgenic rice lines containing high
levels of carotenoids, and addresses the relationship between the rearrangement of transgenes and the presence of metabolic
end products in transgenic rice. 相似文献
17.
Blanco AM Moreno J Del Campo JA Rivas J Guerrero MG 《Applied microbiology and biotechnology》2007,73(6):1259-1266
The growth performance of the chlorophycean microalga Muriellopsis sp. outdoors in open tanks agitated with a paddlewheel and its ability to accumulate carotenoids have been evaluated throughout
the year. The cells grown in the open system had free lutein as the main carotenoid, with violaxanthin, β-carotene, and neoxanthin
also present. Lutein content of the dry biomass ranged from 0.4 to 0.6%, depending on the growth and environmental conditions.
In addition, the biomass of Muriellopsis sp. had a high content in both protein and lipids with about half of the fatty acids being of the polyunsaturated type, with
α-linolenic acid accounting for almost 30% of the total fatty acids. The effect of determinant parameters on the performance
of the cultures in open tanks was evaluated. Operating conditions that allow the maintenance of productive cultures were established
under semicontinuous regime for 9 months throughout the year. Biomass and lutein yields in the open system were not far from
those in closed tubular photobioreactors, and reached productivity values of 20 g dry biomass, containing around 100 mg lutein
m−2 day−1 in summer. The outdoor culture of Muriellopsis sp. in open ponds thus represents a real alternative to established systems for the production of lutein. 相似文献
18.
A carotenoid synthesis gene cluster was isolated from a marine bacterium Algoriphagus sp. strain KK10202C that synthesized flexixanthin. Seven genes were transcribed in the same direction, among which five of them were involved in carotenoid synthesis. This cluster had a unique gene organization, with an isoprenoid gene, ispH (previously named lytB), being present among the carotenoid synthesis genes. The lycopene β-cyclase encoded by the crtY
cd
gene appeared to be a fusion of bacterial heterodimeric lycopene cyclase CrtYc and CrtYd. This was the first time that a fusion-type of lycopene β-cyclase was reported in eubacteria. Heterologous expression of the Algoriphagus crtY
cd
gene in lycopene-accumulating Escherichia coli produced bicyclic β-carotene. A biosynthesis pathway for monocyclic flexixanthin was proposed in Algoriphagus sp. strain KK10202C, though several of the carotenoid synthesis genes not linked with the cluster have not yet been cloned. 相似文献
19.
Vertical and horizontal development of the root system of carrots following green manure 总被引:5,自引:0,他引:5
Cover crops grown as green manure or for other purposes will affect nitrogen (N) distribution in the soil, and may thereby
alter root growth of a succeeding crop. During two years, experiments were performed to study effects of nitrogen supply by
green manure on root development of carrots (Daucus carota L). Total root intensity (roots cm−2 on minirhizotrons) was significantly affected by the green manures, and was highest in the control plots where no green manure
had been grown. Spread of the root system into the interrow soil was also affected by green manure treatments, as the spread
was reduced where spring topsoil Nmin was high. Although N supply and distribution in the soil profile differed strongly among the treatments, no effect was observed
on the rooting depth of the carrot crops. Across all treatments the rooting front penetrated at a rate of 0.82 and 0.68 mm
day−1 °C−1 beneath the crop rows and in the interrow soil, respectively. The minirhizotrons only allowed measurements down to 1 m, and
the roots reached this depth before harvest. Extrapolating the linear relationship between temperature sum and rooting depth
until harvest would lead to rooting depths of 1.59 and 1.18 m under the crop rows and in the interrow soil respectively. Soil
analysis showed that the carrot crop was able to reduce Nmin to very low levels even in the 0.75 to 1.0 m soil layer, which is in accordance with the root measurements. Still, where
well supplied, the carrots left up 90 kg N ha−1 in the soil at harvest. This seemed to be related to a limited N uptake capacity of the carrots rather than to insufficient
root growth in the top metre of the soil.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
20.
Dynamic changes of neoxanthin (NEO), violaxanthin (VIO), anteraxanthin (ANT), zeaxanthin (ZEA), chlorophyll (Chl) a, Chl b, α-carotene, β-carotene, and their behaviour under increasing duration of high irradiance (HI) were investigated in the soybean
hypocotyl callus culture. The calli were induced on solid (1.1 % agar) MS medium (pH 5.8) supplemented with 4.52 μM 2,4-D,
2.32 μM kinetin, and 3 % sucrose. After 30 d of culture, the green calli were irradiated with “white light” (133W m−2) for 0, 3.5, and 24 h. HPLC profiles were separated on a C18 column. With increasing duration of HI, the content of total carotenoids (Cars) increased, but the ratio of Chl a+b/Cars decreased. With lengthening the duration of HI, there was induction of ZEA. Contents of ANT, α-carotene, and β-carotene
remained nearly constant, but ratio of ZEA/Chl a+b increased with lengthening the HI duration.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献