Aβ-Carotene Ketolase Gene NfcrtO from Subaerial Cyanobacteria Confers Drought Tolerance in Rice

Nostoc flagelliforme is a terrestrial cyanobacterium that can resist many types of stressors,including drought,ultraviolet radiation,and extreme temperatures.In this study,we identified the drought tolerance gene NfcrtO,which encodes aβ-carotene ketolase,through screening the transcriptome of N.flagelliforme under water loss stress.Prokaryotic expression of NfcrtO under 0.6 mol/L sorbitol or under 0.3 mol/L NaCl stress significantly increased the growth rate of Escherichia coli.When NfcrtO was heterologously expressed in rice,the seedling height and root length of NfcrtO-overexpressing rice plants were significantly higher than those of the wild type(WT)plants grown on½Murashige and Skoog solid medium with 120 mmol/L mannitol at the seedling stage.Transcriptome analysis revealed that NfcrtO was involved in osmotic stress,antioxidant,and other stress-related pathways.Additionally,the survival rate of the NfcrtO-overexpression lines was significantly higher than that of the WT line under both hydroponic stress(24%PEG and 100 mmol/L H_(2)O_(2))and soil drought treatment at the seedling stage.Physiological traits,including the activity levels of superoxide dismutase,peroxidase,catalase,total antioxidant capacity,and the contents of proline,trehalose,and soluble sugar,were significantly improved in the NfcrtO-overexpression lines relative to those in the WT line under 20%PEG treatment.Furthermore,when water was withheld at the booting stage,the grain yield per plant of NfcrtO-overexpression lines was significantly higher than that of the WT line.Yeast two-hybrid analysis identified interactions between NfcrtO and Dna J protein,E3 ubiquitin-protein ligase,and pyrophosphate-energized vacuolar membrane proton pump.Thus,heterologous expression of NfcrtO in rice could significantly improve the tolerance of rice to osmotic stress,potentially facilitating the development of new rice varieties.

Dietary Supplementation of β-Carotene Reveals miRNAs Involved in the Regulation of Carotenoid Metabolism in Crassostrea gigas

Carotenoids play crucial physiological roles in animals.A comprehensive investigation into the mechanism of carotenoid metabolism in oysters will establish a theoretical foundation for further development of its carotenoid-rich traits.However,the information on the function of miRNA in β-carotene metabolism in oysters is limited.To elucidate the mechanisms underlying miRNA regulation of carotenoid metabolism in oysters,we compared the expressions of miRNA in digestive gland tissues of Pacific oyster(Crassostrea gigas)fed with aβ-carotene supplemented diet and a normal diet,respectively.A total of 690 candidate miRNAs in the Pacific oyster digestive gland tissues were identified,including 590 known miRNAs and 111 unknown miRNAs.Three differentially expressed miRNAs were obtained in the carotenoid-fed and normal groups,associated to 137 differentially expressed target genes.Moreover,the GO enrichment analysis revealed that the differentially expressed target genes were mainly involved in transmembrane transport activity.KEGG enrichment showed that the differentially expressed target genes were involved in ABC transport.Analysis of the mRNA-miRNA network revealed that novel0025 played a central role in carotenoid metabolism,and it was negatively correlated with the expression of 46 mRNAs.In addition,down-regulated expression of novel0025 upregulated the expression of the lipoprotein gene LOC105342186,suggesting a potential regulatory role in carotenoid metabolism.Our results provide useful information for elucidating the miRNA regulation mechanism during carotenoids metabolism in the Pacific oyster.

Study on the interaction between β-carotene and gut microflora using an in vitro fermentation model

β-Carotene,a typical non-oxygenated carotenoid,is the most efficient source of retinol(VA).The low bio-availability ofβ-carotene lead to large accumulation in colon;however,the relationship betweenβ-carotene and gut microflora remains unclear.This study intends to explore the interaction betweenβ-carotene and gut microflora using an in vitro fermentation model.After 24 h fermentation,the degradation rate ofβ-carotene was(64.28±6.23)%,which was 1.46 times that of the group without gut microflora.Meanwhile,the production of VA was nearly 2 times that of the group without gut microflora,indicating that the gut microflora can metabolizeβ-carotene into VA.β-Carotene also influences the production of short-chain fatty acids(SCFAs),the production of total SCFAs in 0.5 mg/mLβ-carotene(BCM)group was(44.00±1.16)mmol/L,which was 2.26 times that of the blank control(BLK)group.Among them,the production of acetic acid in BCM group was(19.06±0.82)mmol/L,which was 2.64 time that of the BLK group.Furthermore,β-carotene significantly affected the structure and composition of gut microflora,increasing the abundance of Roseburia,Parasutterella and Lachnospiraceae,and decreasing the abundance of Dialister,Collinsella and Enterobacter(P<0.05).This study provides a new way to understand howβ-carotene works in human body with gut microflora.

Dynamic Accumulation of β-carotene and Dry Matter in Orange-fleshed Sweetpotato [Ipomoea batatas(L.) Lam] and Their Correlation Analysis

Using three orange-fleshed sweetpotato varieties as experimental materials,16 economic traits at 60 d,75 d,90 d,105 d,120 d and 135 d after planting were measured,so as to revealing the dynamic variations of β-carotene and dry matter accumulation in roots and their relationships with economic traits in orangefleshed sweetpotato.The results showed that the dynamic variations of β-carotene accumulation in tubers varied hugely among different varieties.Interesting,the βcarotene content of all three varieties showed a significant decrease after 120 d,while the dry matter content of them performed a similar ＂fluctuation-type＂.Correlation analysis indicated that β-carotene content of three orange-fleshed sweetpotato varieties had no significant correlation with dry matter content and photosynthetic parameters,but the correlation with other economic traits also varied among varieties.

Isomerization and degradation of all-trans-β-carotene during in-vitro digestion

To investigate the behavior of all-trans-β-carotene during digestion,in-vitro digestion coupled with HPLC-DAD,Raman spectroscopy and Fourier transform-infrared spectroscopy were used to monitor it.All-trans-β-carotene reduced by 75%during the in-vitro digestion and had a highest degradation during intestinal digestion compared with oral and gastro digestion.All-trans-β-carotene occurred isomerization and degradation during oral digestion and occurred degradation during gastro and intestinal digestion.Isomers were identifi ed as 15-cis-β-carotene and 9-cis-β-carotene,degradation products were compounds with function group of C—O,C—O—C or C=C—C=C.The biological fate ofβ-carotene during digestion was clarifi ed,and one of the reasons for low bioavailability ofβ-carotene was explained by high degradation rate during digestion.

Observation of Fundamental and High Order Raman Modes of β-Carotenes in Pd OECC Thin Film by SERS

Raman spectra of purified oxygen evolution core complexes (Pd OECC) thin films on silver mirror substrates have been taken over the frequency range of 250-3100 cm -1 by surface enhanced Raman scattering (SERS). Besides the fundamental frequency modes of β_carotene in Pd OECC, many weak peaks are observed. According to the selection rules of overtone and combination bands, most of them are attributed to the second_order Raman spectra of β_carotene. Compared with the SERS of normal Pd OECC, the SERS of Pd OECC after strong illumination shows a decrease in scattering intensity and an increase in line widths, indicating changes of conformation and micro_environment of β_carotene. The results of SERS are consistent with the changes of absorption spectrum of Pd OECC induced by strong illumination. There are no changes that can be ascribed to new vibration bands, so it is deduced that Pd OECC on the silver mirror is identical to that in the solution. In summary, SERS proved a good method to study the photodamage mechanism of photosynthesis.

Measurement and Influence Factors of the Flowability of Microcapsules with High-content β-Carotene

The flowability of five kinds of microencapsulation powders,with differentβ-carotene contents and by two alternative particle-forming technologies i.e.spray-drying and starch-catching beadlet technology,was meas- ured.The actual flow properties of the five powders were compared based on bin-flow test,and three flow indexes (Hausner ratio,repose angle and flow index)were measured.It was found that the repose angle is the most suitable index to reflect the flowability of these powders for the particle properties would not be altered due to compaction or tapping during the measuring process.Particle size and particle size distribution play most important roles in the flowability of these granular materials,which was also influenced by other factors like shape,surface texture,sur- face roughness,etc.Microcapsules with wall material of gelatin and a layer of modified starch absorbed on the sur- face showed excellent flowabilities and good mechanical properties,and they are favorable for tabletting to supply β-carotene.

Biochemical changes in phenols,flavonoids,tannins,vitamin E,β-carotene and antioxidant activity during soaking of three white sorghum varieties

Objective:To investigate the changes in total phenols,flavonoids,tannins,vitamin E, β-carotene and antioxidant activity during soaking of three white sorghum varieties.Methods: The changes in total phenols,total ilavonoids,tannins,phenolic acids compounds,flavonoid components,vitamin E,P-carotene and antioxidant activity during soaking of sorghum grains were determined.Results:Total phenols,total flavonoids,tannins,vitamin E,P-carotene and antioxidant activity in raw sorghum were ranged from 109.21 to 116.70,45.91 to 54.69,1.39 to 21.79 mg/100 g,1.74 to 5.25,0.54 to 1.19 mg/kg and 21.72%to 27.69%and 25.29%to 31.97%,respectively. The above measured compounds were significantly decreased after soaking.p-Hydroxybenzoic acid,vanillic acid,syringic acid and cinnamic acid represent the major phenolic acids in Dorado variety.While ferulic acid,p-coumaric acid,gallic acid and caffeic acid represent the major phenolic acids in Shandaweel-6.On the other hand,protocatechuic acid represents the major phenolic acids in Giza-15.Regarding flavonoids components,Dorado was the highest variety in kampferol and naringenin while Shandaweel-6 was the highest variety in luteolin, apigenin,hypersoid,quercelin and christen.Finally,Giza-15 was the highest variety in catechin. Phenolic acids,flavonoid compounds and antioxidant activities were decreased after soaking. Conclusions:Sorghum varieties have moderate quantities from total phenols,total flavonoids, tannins,phenolic acids compounds,flavonoid components,vitamin E,P-carotene and antioxidant activity which decreased after soaking.

Application of derivative ratio spectrophotometry for determination of β-carotene and astaxanthin from Phaffia rhodozyma extract

A derivative ratio spectrophotometric method was used for the simultaneous determination of β-carotene and astaxanthin produced from Phaffia rhodozyma. Absorbencies of a series of the standard carotenoids in the range of 441 nm to 490 nm demonstrated that their absorptive spectra accorded with Beer’s law and that the additivity when the concentrations of β-carotene and astaxanthin and their mixture were within the range of 0 to 5 μg/ml, 0 to 6 μg/ml, and 0 to 6 μg/ml, respectively. When the wavelength interval (?λ) at 2 nm was selected to calculate the first derivative ratio spectra values, the first derivative amplitudes at 461 nm and 466 nm were suitable for quantitatively determining β-carotene and astaxanthin, respectively. Effect of divisor on derivative ratio spectra could be neglected; any concentration used as divisor in range of 1.0 to 4.0 μg/ml is ideal for calculating the derivative ratio spectra values of the two carotenoids. Calibration graphs were established for β-carotene within 0?6.0 μg/ml and for astaxanthin within 0?5.0 μg/ml with their corresponding regressive equations in: y=?0.0082x?0.0002 and y=0.0146x?0.0006, respectively. R-square values in excess of 0.999 indicated the good linearity of the calibration graphs. Sample recovery rates were found satisfactory (>99%) with relative standard deviations (RSD) of less than 5%. This method was suc- cessfully applied to simultaneous determination of β-carotene and astaxanthin in the laboratory-prepared mixtures and the extract from the Phaffia rhodozyma culture.

Mutation Breeding of β-carotene Producing Strain B. trispora by Low Energy Ion Implantation

Ion beam bioengineering technology as a new mutation approach has been widely used in the biological breeding field. In this paper the application of low energy nitrogen ion implantation in the β-carotene producing strain, Blakeslea trispora（-） was investigated. The effects of different fermentation conditions on β-carotene production by a high yield strain were examined. Results showed that two β-carotene high yielding strains B.trispora（-） BH3-701 and BH3-728 were screened out and the averaged production of β-carotene was raised by 178.7% and 164.6% respectively after five passages in the shaking flasks. Compared with the original strain, the highest yield strain BH3-701 was potent in accumulating β-carotene, especially in the later stage, and greatly increased production efficiency.

Combining Ability and Parent-Offspring Correlation of Maize(Zea may L.) Grain β-Carotene Content with a Complete Diallel

Vitamin A deficiency has become a worldwide problem.Biofortified foods can potentially be an inexpensive,locally adaptable,and long-term solution to dietary-nutrient deficiency.In order to improve the β-carotene content in maize grain by breeding and minimize vitamin A deficiency,a complete diallel cross was designed with eight inbred lines of maize,and 64 combinations were obtained in this study.The experimental combinations were planted in Yunnan and Sichuan provinces,respectively,with a random complete block design.The β-carotene contents in the grains of the experimental materials were analyzed by high-performance liquid chromatography.Among the tested materials,the effect difference of general combining ability of the β-carotene content was significant;however,the effect difference of the special combining ability and the reciprocal effect were not significant.The β-carotene content of maize grain was not influenced significantly by the cross and the reciprocal cross.There was a significant correlation about the β-carotene content in the maize grains between the F 1 and their parents.The combinations with high β-carotene content were obviously influenced by the environment,and the mean value of β-carotene content for the experimental materials planted in Ya＇an of Sichuan was higher than that planted in Yuanjiang of Yunnan,with the results being significant at the 0.01 level.

Experimental measurement and correlation of solubility of β-carotene in pure and ethanol-modified subcritical water

For the first time,the solubility ofβ-carotene in pure and ethanol-modified subcritical water(SW)using the static method was determined.The experimental runs were performed at a temperature ranging from 298.15 to 403.15 K and 0–10%(w/w)of ethanol as a modifier at a constant pressure of 5 MPa.Samples were analyzed by UV–vis spectrophotometer.The solubility ofβ-carotene was found to range from 1.084×10^-8 to 227.1×10^-8 mol fractions in the subcritical water in above mentioned conditions.The obtainedβ-carotene solubility data were correlated using the linear model and modified Apelblat model.The obtained results showed the modified Apelblat model was better for estimating the solubility ofβ-carotene in SW.The values of the rootmean-square deviation(RMSD)between experimental and correlated data were calculated and used as the index of validity and accuracy for the model.Also,thermodynamic properties of the solution such as the Gibbs free energy of solution,enthalpy,and entropy of solution were estimated.

Stimulated supercontinuum-radiation generation of carbon disulfide by all-trans-β-carotene fluorescence enhancement effect in liquid core optical fibre

We demonstrate stimulated supercontinuum-radiation of carbon disulfide （CS2） influenced by biological molecules all-trans-stimulated Raman scattering, stimulated Brillouin scattering, all-trans-β-carotene, liquid core optical fibre-carotene in liquid core optical fibre （LCOF）. By virtue of the broad fluorescence characteristics and large third-order optical nonlinearities of all-trans-β-carotene, the high-order Stokes lines of stimulated Raman scattering （SRS） and the multi-order Stokes lines of stimulated Brillouin scattering （SBS） excitated by SRS are observed at low input-laser energies. The results indicate that the fluorescence not only enhances the SRS, but also the SBS. These Stokes lines generate the SRS-SBS supercontinuum radiation （RBSR）. A flat-amplitude bandwidth of 110 nm from 515 nm to 625 nm is observed when a frequency-doubled Nd：YAG laser at 532 nm with an energy of 0.86 mJ is used. This result is expected to be useful for the multi-wavelength fibre laser.

EFFECT OF NITRATE AND PHOSPHATE ON ACCUMULATION OF β-CAROTENE ISOMERS IN DUNALIELLA SALINA

DunaIiella salina, a halotolerent unicellular green alga, can accurmulate a Iarge amount of β-caroteneunder environmental conditions. The isorners of β-carotene extIacted from D. salina culturedin medium with different nitrate and phosphate concentrations were analysed by HPLC with Alox-Talumins column. At least six isomers were found in different proportions depending on the culture me-dia’s nitrate and/or phosphate concentrations. Nitrate and/or phosphae defidency was conducive tothe accumulation of totaI cis isomers but not of al1 trans isomer. lt is sUggeSted that 1 mmol/L KNO3and 0.1 mmol/L KH2, PO4 are favourable for accumulation of total cis β-carotene.

Study of second-order nonlinear hyperpolarisability of all-trans-β-carotene in solutions by linear spectroscopic technique

This paper demonstrates the second-order nonlinear hyperpolarisability γ of all-trans-β-carotene in different solvents by linear spectroscopic technique that is based on resonance Raman scattering and UV-VIS （Ultraviolet-visible） absorption spectroscopy. Owing to the two-level model well describing the link that exists between the resonance Raman scattering and stimulated Raman scattering, the stimulated Raman polarisability αR can be calculated through the two-photon resonance system. The value of γ of all-trans-β-carotene in carbon bisulfide solution is 6.435×10^-33 esu （1 esu of resistance = 8.98755×10^11Ω） that is close to the true value, because the solution of all-trans-β-carotene in carbon bisulfide satisfies the rigid resonance Raman scattering condition. This method is expected to be worthy of applications to measure the second-order nonlinear hyperpolaxisability of a conjugate organic molecule.

Difference in effect of temperature on absorption and Raman spectra between all-trans-β-carotene and all-trans-retinol

Temperature dependencies （81 ℃- 18 ℃） of visible absorption and Raman spectra of all-trans-β-carotene and all-trans-retinol extremely diluted in dimethyl sulfoxide are investigated in order to clarify temperature effects on different polyenes. Their absorption spectra are identified to be redshifted with temperature decreasing. Moreover, all-trans-β-carotene is more sensitive to temperature due to the presence of a longer length of conjugated system. The characteristic energy responsible for the conformational changes in all-trans-β-carotene is smaller than that in all-transretinol. Both of the Raman scattering cross sections increase with temperature decreasing. The results are explained with electron-phonon coupling theory and coherent weakly damped electron-lattice vibrations model.

Solvent effects on the S_0→S_2 absorption spectra of β-carotene

Absorption spectra of β-carotene in 31 solvents are measured in ambient conditions. Solvent effects on the 0-0 band energy, the bandwidth, and the transition moment of the S0 → S2 transition are analysed. The discrepancies between published results of the solvent effects on the 0-0 band energy are explained by taking into account microscopic solutesolvent interactions. The contributions of polarity and polarizability of solvents to 0-0 band energy and bandwidth are quantitatively distinguished. The 0- 0 transition energy of the S2 state at the gas phase is predicted to locate between 23000 and 23600 cm^-1.

Production of β-Carotene by a Newly Isolated Rhodotorula Glutinis UCP1555 Strain and Cytotoxic Effect Evaluation

Carotenoids have attracted greater attention due to the beneficial role on human health. It is an essential nutrient and has some biological functions such as species-specific coloration, photoprotection, light absorbing, which is an important component because of its role as precursor of vitamin A. In this study was performed the production of fl-Carotene by Rhodotorula glutinis UCP/WFCC 1555 in presence and absence of blue and white using LED （light-emitting diodes） and evaluation of the cytotoxic effect. The production was investigated in low cost medium constituted by different concentrations of CG （crude glycerin） and CSL （corn steep liquor） from the CCD （Central Composite Design） and the identification and yield of the β-Carotene was investigated by chromatographic profile （HPLC）. Additionally, the fl-Carotene produced was tested to evaluate its cytotoxic effect in human tumor cells MCF-7 （breast cancer） and HL-60 （promyelocytic leukemia） and healthy cells of macrophages. The results showed that in the medium composed by 6% glycerin and 0.6% corn steep liquor, in the absence of light, occurred the maximum production of total carotenoids with values of 160μg·g-1 and these 100.60μg·g-1 correspond to the β-Carotene that showed ability in inhibit cell growth in several tumor cells such as MCF-7 cells （breast cancer） and HL-60 （promyelocytic leukemia）.

Removal of Carbonyl-Containing Effluents by Photodegradation Using β-Carotene Embedded onto Zinc Oxide Particles

Environmental pollution especially in the form of effluent wastewater from industries has been a major challenge. Carbonyl-containing organic standards and sewage sample were effectively photo degraded. ZnO nanoparticles were prepared by emulsification of zinc-carbamate solution using 1 N NaOH and grafted chemically by Molecular Layer Doping method at 180 °C with β-carotene extracted using methanol by refluxing at 50 °C at varying concentrations. Intrinsic and grafted β-carotene ZnO were characterized using FTIR (Fourier transform infrared spectroscopy) and their spectra differed in an additional peak at around 1,435 nm corresponding to the organ metallic bond Zn-C. UV-Vis spectra of the two composites indicated a blue shift in the grafted samples. This translated to a reduced band gap from 3.5 eV to 3.4 eV. Comparison in the rates of photodegradation of pure organic compounds, organic effluents and color change of dyes was in the order 1% grafted, 0.5% grafted, intrinsic ZnO and blank sample. When 10.0 mL of sewerage water was photo degraded using both sunlight and UV-Lamp for 40 minutes, the amount of carbonyls present decreased by 28.5% for β-carotene grafted ZnO, 24.5% for intrinsic ZnO and 0.6% for a blank sample.

The Protective Role of β-Carotene and Hesperidin on Some Hematological and Myocardial Measurements against Imidacloprid Toxicity in Albino Rats

Neonicotinoids including IM （Imidacloprid） are widely used as plant systemic insecticides. Several studies have indicated that pesticide toxicity may be associated with the enhanced production of ROS （reactive oxygen species）. Both β-carotene （I3C） and hesperidin （H） have an antioxidant property and quench free radicals. This study aimed to clarify the protective role of β-carotene and hesperidin as natural antioxidants on IM induced toxicity in hematological parameters and markers of cardiac muscle activity in male albino rats. The treatment of rats with IM showed a significant decrease in hemoglobin （Hb %）, MCH （mean corpuscular hemoglobin）, MCHC （mean corpuscular hemoglobin concentration）, HCT （hematocrit） values and RBCs count comparing with control group. On the other hand, MCV （mean corpuscular volume）, WBCs （white blood cells） and Pits （platelets） count pronounced a significant increase in IM group comparing to control. Also, αFP （plasma alpha fetoprotein）, CEA （carcinoembryonic antigen）, CK （creatine kinase）, CK-MB （creatine phosphokinase myocardial band） and LDH （lactate dehydrogenase） clarify a significant increase in IM group comparing to control. Both β-carotene and hesperidin mitigate the deleterious effects of IM on previous parameters. β-Carotene and hesperidin may protect hematopoietic system and heart muscle against toxicity of IM. These improvements of the results clarify the protective effect of the used antioxidants. Conclusion： β-carotene and hesperidin, natural antioxidants, have a protective effect against IM evoked hematological and biochemical changes.