Search

Currently, the chemically synthesized carotenoid pigments, fulfill the needs of the consumers and industries. However, owing to their toxic effects, the use of such chemical oriented pigment products have limitations by restrictions of usage; and such restrictions have necessitated finding ecofriendly alternative pigments. By the way, bacteria, fungi and plants are the prospective alternative natural resources for the production of pigments, similar to carotenoids. Carotenoids are natural pigments that are used widely in nutraceutical, food and pharma industries. Lately, the biological production of carotenoids from microbes has been receiving greater attention and in this aspect, the studies on bacterial sources are emerging proportionally. During a screening process of pigmented strains, the bacterial strain, Dietzia maris AURCCBT01 was isolated and on further study found it to be a producer of canthaxanthin. The process parameters for biomass and canthaxanthin production were statistically optimized using response surface methodology. The effect of process parameters, namely glucose (5–20 g/L), NaCl (0.2 – 1.0 g/L) and pH (5 – 7) on the biomass and canthaxanthin production were studied. The optimal conditions for biomass and canthaxanthin production were glucose, 12.5 g/L; NaCl, 0.6 g/L and pH, 7 resulting in the highest canthaxanthin yield of 2997 µg/L and biomass of 3.03 g/L. The results exposed that these three process variables had greater influence on the production of canthaxanthin by the strain Dietzia maris AURCCBT01. The scale-up study was carried out in a jar fermenter under the optimized conditions. The maximum production for canthaxanthin and biomass was 3103 µg/L, 3.2 g/L was achieved respectively, and the results are encouraging for optimization under industrial conditions.

The objective of this study was to evaluate the effects of the dietary supplementation of canthaxanthin and cholecalciferol (25OHD3) to broiler breeders and their progenies on their performance. Eighty 25-wk-old Cobb 500 broiler breeders were distributed according to a completely randomized design in 2 experimental treatments, with 10 replicates of 4 birds each. The treatments consisted of the supplementation or not of a corn–soybean meal diet with canthaxanthin + 25OHD3 to broiler breeders fed from 25 to 62 wk of age. Egg production, fertility, hatchability, hatchability of fertile eggs, embryonic mortality, and egg specific gravity were evaluated. Breeders were inseminated at 35, 45, and 62 wk of age, the eggs were incubated, and the performance of the progenies was evaluated. From the progeny of each breeder age, 300 male chicks were distributed according to a completely randomized design in a 2 × 2 factorial arrangement (chicks from breeders supplemented or not with canthaxanthin + 25OHD3 and chicks supplemented or not with canthaxanthin + 25OHD3), totaling 4 treatments with 5 replicates of 15 birds each. Canthaxanthin + 25OHD3 were supplied to the chicks until 21 D of age. The combination of canthaxanthin and 25OHD3, containing 69mg of 25OHD3 and 6g of canthaxanthin, was supplemented at 1kg/t of feed. Breeders supplemented with canthaxanthin + 25OHD3 showed higher egg production, total hatchability, hatchability of fertile eggs, and lower early embryo mortality compared with those fed the control diet. Broilers from breeders fed canthaxanthin + 25OHD3 and supplemented with this additive up to 21 D of age presented a better feed conversion ratio and higher carcass and breast yields than those derived from nonsupplemented breeders.

Two new scallop strains, the ‘QN Orange’ scallop and the ‘Bohai Red’ scallop, were selected from the hybrid cohort between the bay scallop (Argopecten irradians irradians) and the Peruvian scallop (Argopecten purpuratus) to improve the bay scallop stock, which has suffered from significant inbreeding depression characterized by poor growth and high mortality. Although both strains were originated from the same hybrid cohort, the ‘QN Orange’ scallops possess orange adductor muscles while the ‘Bohai Red’ scallops have white adductor muscles. To explore the pigment profiles of adductor muscle coloration in these two scallop strains, an optimized method based on liquid chromatography coupled with triple quadrupole mass spectrometry (HPLC-QqQ-MS) with atmospheric pressure chemical ionization (APCI) was established to determine chlorophyll (chlorophyll a and chlorophyll b) and carotenoids (including α-carotene, β-carotene, e-carotene, γ-carotene, ζ-carotene, lutein, fucoxanthin, zeaxanthin, canthaxanthin, pectenoxanthin, and pectenolone). The results showed that the total contents of carotenoids in the adductor muscle, gill, and mantle of ‘QN Orange’ scallops were 82.68, 105.49, and 100.49 μg g−1, which were 49.88, 3.26, and 4.18 times higher than those in the ‘Bohai Red’ scallops, respectively. In particular, the contents of the pigments pectenolone, pectenoxanthin, fucoxanthin, zeaxanthin, and lutein in the ‘QN Orange’ scallops were 171.58, 61.67, 3.87, 22.16 and 23.27 μg g−1, which were 6.92, 3.38, 27.64, 15.75, and 13.00 times higher than those in the ‘Bohai Red’ scallops, respectively. These results suggest that the orange coloration in the ‘QN Orange’ scallops might be caused by the accumulation of carotenoids.

Impacts of different pre-treatments of cephalothorax from Pacific white shrimp before ultrasound assisted extraction (UAE) on yield and characteristics of lipids were studied. Autolysis at 50 °C for 3 h in the absence and presence of 0.1% tannic acid (TA), a lipase inhibitor, was implemented. Pre-heating of cephalothorax containing 0.1% TA at 95 °C for different times (15–45 min) was also carried out. When UAE was used to extract the lipids at the ultrasonic amplitude of 80% for 25 min in continuous mode, samples with pre-heating rendered the highest lipid yield (13.3g-14.1 g/100 g sample). Pre-heating along with TA addition resulted in suppression of lipid oxidation as evidenced by decrease in peroxide value (PV) and thiobarbituric acid reactive substances (TBARS). Free fatty acid (FFA) content was also found to be lower, whereas the control (without pre-treatment) had higher FFA. Fourier transform infrared (FTIR) spectra confirmed lower oxidation in lipid from pre-heated samples added with TA. Lipid contained astaxanthin, astaxanthin monoester, astaxanthin diester, canthaxanthin and β-carotene. Overall, the combination of pre-heating and addition of TA was a promising means to increase the yield and maintain the quality of lipid from cephalothorax using UAE.

Apples may suffer sunburn during growing season because of photooxidation damage. Astaxanthin have a stronger antioxidant activity against photooxidation compared to its precursors zeaxanthin and β-carotene. Here, we transferred β-carotene ketolase (bkt) and β-carotene hydroxylase (crtR-B), two genes encoding key enzymes for astaxanthin biosynthesis, into “Brookfield Gala” apple plants using pCAMBIA1302-bkt-crtR-B via transformation mediated by Agrobacterium tumefaciens EHA105. We aimed to confer a stronger antioxidant ability against sunburn to apple plants by regulating metabolic pathways of carotenoids. RT-PCR and qPCR analysis confirmed that bkt and crtR-B genes were expressed simultaneously in transgenic plants. Southern blotting analysis confirmed that the transgene was stably integrated and determined transgene copy number. Transgenic plants synthesized novel ketocarotenoids, resulting in an accumulation of astaxanthin up to 12.06 μg/g and of canthaxanthin up to 6.38 μg/g per leaf fresh weight. The light antioxidant ability of transgenic plantlets was stronger than that of non-transgenic ones in high light conditions. We speculate that the transgenic apples accumulating astaxanthin are resistant to photooxidation and can therefore prevent sunburn.

Canthaxanthin is widely used as a feed additive to improve skin and yolk color in poultry. It is insoluble in water and sensitive to oxidation, so commercial canthaxanthin is often microencapsulated with wall materials to improve its solubility and stability. The objective of this study was to evaluate the effects of canthaxanthin microencapsulation on yolk color and canthaxanthin deposition in egg yolk of laying hens. A total of 288 Hyline Brown laying hens (48 wk of age) were allocated to 4 groups with 6 replicates of 12 hens each, and fed a basal diet or the basal diet supplemented with 5 mg/kg canthaxanthin microencapsulated with modified starch (CMMS), gelatin (CMG), and sodium lignosulfonate (CMSL), respectively. Canthaxanthin supplementation did not affect laying performance of hens, but improved (P0.05) yolk color of fresh, fried, boiled, and stored (4 and 25°C) eggs. The improvement of yolk color of fresh eggs was greatest in the CMSL group and least in the CMG group (P0.05). Both CMMS and CMSL resulted in higher (P0.05) yolk canthaxanthin concentration than CMG. The CMSL resulted in higher (P0.05) yolk color score of fried eggs than CMMS and CMG and higher (P0.05) yolk color score of boiled eggs than CMG, but no difference was observed in stored eggs among three canthaxanthin groups. In conclusion, CMMS and CMSL were more effective in yolk pigmentation than CMG, and CMSL was slightly better than CMMS.

For nine symmetric natural carotenoids, a comprehensive thermodynamics study of processes associated with their radical scavenging activity is proposed. We have investigated the hydrogen atom transfer (HAT) from the parent carotenoid, mono-radical species, radical cations and radical anions. Electron transfer and proton transfer reactions were also studied. Terminal units and carbon atoms in their vicinity were identified as thermodynamically favoured reaction sites of the HAT mechanism. Rhodoxanthin, canthaxanthin and astaxanthin, as strong antioxidants, without any pro-oxidative effect, were found to have bond dissociation enthalpies (BDE) higher than 300 kJ mol −1 and the most negative electron affinities. The electron transfer to a carotenoid is exothermic, while other studied reactions are endothermic. In solvent, the electron transfer reactions may be preferred instead of hydrogen atom transfer.

International audience; Thraustochytrids are marine protists highly ecologically relevant in mangrove environments. The family Thraustochytriaceae underwent profound taxonomical rearrangements in the last decade, with the description and emendation of several genera. Here, we identified two new thraustochytrid strains (CCAP 4062/1 and CCAP 4062/3) collected from the same mangrove environment in Mayotte Island (Indian Ocean) and representative of two sister clades in the phylogenetic Aurantiochytrium super Glade. Phylogenomic (on 2389 genes) and phylogenetic analyses on 18S rDNA sequences led us to propose the description of a new genus, Hondaea gen. nov. (CCAP 4062/3), closely related and pseudo-cryptic to Aurantiochytrium (CCAP 4062/1). Compared to Aurantiochytrium, Hondaea did not produce amoeboid cells and its zoospores were smaller. Chemotaxonomical traits, such as fatty acid, sterol, and carotenoid profiles measured along the growth curves, validated the new genus description. Genome sequencing and manual annotation of lipid metabolism genes revealed similar pathways in both strains. However, such pathways showed different dynamics during the growth phases. Aurantiochytrium accumulated carotenoids (canthaxanthin) and large amounts of triacylglycerols enriched in omega 3-docosahexaenoic acid in the stationary phase, while squalene and free cholesterol increased during the early exponential phase. In contrast, Hondaea accumulated low amounts of triacylglycerols enriched in odd and saturated fatty acids during the early exponential phase, whereas free-sterol and carotenoid contents were little affected. These results suggest that these genera evolved independently, although phylogenetically and ecologically closely related. This comparative study also showed that the biotechnological potential of thraus-tochytrids cannot be deduced solely from phylogenetic and genomic analyses.

Carotenoids are valuable natural colorants that exhibit numerous health promoting properties, and thus are widely used in food, feeds, pharmaceutical and nutraceuticals industries. In this study, we isolated and identified novel microbial sources that produced high-value carotenoids using high throughput screening (HTS). A total of 701 pigmented microbial strains library including marine bacteria and red yeast was constructed. Carotenoids profiling using HPLC-DAD-MS methods showed 88 marine bacterial strains with potential for the production of high-value carotenoids including astaxanthin (28 strains), zeaxanthin (21 strains), lutein (1 strains) and canthaxanthin (2 strains). A comprehensive 16S rRNA gene based phylogenetic analysis revealed that these strains can be classified into 30 species belonging to five bacterial classes (Flavobacteriia, α-Proteobacteria, γ-Proteobacteria, Actinobacteria and Bacilli). Importantly, we discovered novel producers of zeaxanthin and lutein, and a high diversity in both carotenoids and producing microbial strains, which are promising and highly selective biotechnological sources for high-value carotenoids.

Three experiments were conducted to investigate the effects of maternal dietary canthaxanthin (CX) and 25-hydroxycholecalciferol (25-OH-D3) supplementation on antioxidant status and calcium-phosphate metabolism of progeny ducks. Cherry Valley duck breeders (38 wk old) were fed either a control diet or the same diet plus CX (6 mg/kg) and 25-OH-D3 (0.069 mg/kg) for 32 weeks. Experiments 1, 2, and 3 were conducted with progeny ducks hatched from eggs laid by duck breeder hens at 54, 62, and 70 wk of age, respectively. Progeny ducks from both maternal treatments were fed with the same NRC (1994) vitamin regimen starter (1 to 14 d) and finisher (15 to 35 d) diets in experiments 1 and 2, and fed with the same high vitamin regimen starter (1 to 14 d) and finisher (15 to 35 d) diets in experiments 3. High vitamin regimen had higher levels of all vitamins, except biotin, than the NRC (1994) vitamin regimen. In experiment 1, maternal CX and 25-OH-D3 increased (P < 0.05) shank pigmentation and tibiotarsus ash and tended to decrease (P < 0.1) liver total superoxide dismutase activity (T-SOD) of one-day-old progeny ducks; and increased (P < 0.05) shank pigmentation, decreased (P = 0.05) liver protein carbonyl, and tended to increase (P < 0.1) liver total antioxidant capacity (T-AOC) of 14-day-old progeny ducks. In experiment 2, maternal CX and 25-OH-D3 increased (P < 0.05) shank pigmentation and liver T-AOC and decreased (P < 0.05) liver protein carbonyl of one-day-old progeny ducks, but increased (P < 0.05) the serum phosphate level of 14-day-old progeny ducks. In experiment 3, maternal CX and 25-OH-D3 increased (P < 0.05) shank pigmentation of one-, 14-, and 35-day-old progeny ducks and tended to increase (P < 0.1) liver T-SOD and tibiotarsus ash, but decrease (P < 0.1) liver malondialdehyde of one-day-old progeny ducks. It can be concluded that progeny dietary high vitamin regimen could partially prevent maternal CX-derived progeny shank pigmentation from bleaching. Maternal CX- and 25-OH-D3-derived effects are influenced by the hen's age and progeny's dietary vitamin regimen.

Cellulosic nanocrystals from different origins were made to stabilize the canthaxanthin (CTX) in pickering emulsion. Nanocrystals were obtained by hydrochloric acid hydrolysis. Dynamic light scattering (DLS) demonstrated that the length of solid particles were in the range of 112nm-4000nm. AFM indicated the needle-like shape of the cotton cellulose nanocrystals (CCNs) and bacterial cellulose nanocrystals (BCNs) and also illustrated the thickness of the particles to be 6 and 7nm respectively. The crystallinity of both BCNs and CCNs was higher than the cellulose source they were isolated (CL: 75.4%, CCNs: 86.6; BC: 79.2%, BCNs: 88.5%). Effects of different factors such as temperature, pH and ionic concentration on stability were investigated. The results revealed that an increase in both temperature and pH was accompanied by an improvement in emulsion stability in all tested samples. However, increase in ionic concentration resulted in emulsions with less stability. In all the samples, CCN emulsions had better stability than the BCN emulsions, which was associated to smaller particle size and more coverage ability. Test of stability to light showed that CCN emulsions can preserve CTX better than BCN against the light.

Picochlorum celeri has among the fastest photoautotrophic growth rates (~2 h doubling time in optimal conditions) reported to date for a marine alga. This study comprehensively analyzes the levels of Picochlorum celeri photosynthetic pigments, which can reach up to ~13% of the total particulate organic carbon (POC) under light-limiting conditions. The main Picochlorum celeri pigments identified include: chlorophyll a, chlorophyll b, lutein, β-carotene, canthaxanthin, violaxanthin, neoxanthin, zeaxanthin and antheraxanthin. The ketocarotenoid canthaxanthin can accumulate up to 120 mg L−1 in Picochlorum celeri liquid culture; ~12% of it was found in an extracellular polysaccharide matrix. Using a solar-simulating automated photobioreactor, we monitor the photoacclimation of cultures maintained in unshaded conditions (

Astaxanthin is a red-colored carotenoid, used as food and feed additive. Astaxanthin is mainly produced by chemical synthesis, however, the process is expensive and synthetic astaxanthin is not approved for human consumption. In this study, we engineered the oleaginous yeast Yarrowia lipolytica for de novo production of astaxanthin by fermentation. First, we screened 12 different Y. lipolytica isolates for β-carotene production by introducing two genes for β-carotene biosynthesis: bi-functional phytoene synthase/lycopene cyclase ( crtYB ) and phytoene desaturase ( crtI ) from the red yeast Xanthophyllomyces dendrorhous . The best strain produced 31.1 ± 0.5 mg/L β-carotene. Next, we optimized the activities of 3-hydroxy-3-methylglutaryl-coenzyme A reductase ( HMG1 ) and geranylgeranyl diphosphate synthase ( GGS1/crtE ) in the best producing strain and obtained 453.9 ± 20.2 mg/L β-carotene. Additional downregulation of the competing squalene synthase SQS1 increased the β-carotene titer to 797.1 ± 57.2 mg/L. Then we introduced β-carotene ketolase ( crtW ) from Paracoccus sp. N81106 and hydroxylase ( crtZ ) from Pantoea ananatis to convert β-carotene into astaxanthin. The constructed strain accumulated 10.4 ± 0.5 mg/L of astaxanthin but also accumulated astaxanthin biosynthesis intermediates, 5.7 ± 0.5 mg/L canthaxanthin, and 35.3 ± 1.8 mg/L echinenone. Finally, we optimized the copy numbers of crtZ and crtW to obtain 3.5 mg/g DCW (54.6 mg/L) of astaxanthin in a microtiter plate cultivation. Our study for the first time reports engineering of Y. lipolytica for the production of astaxanthin. The high astaxanthin content and titer obtained even in a small-scale cultivation demonstrates a strong potential for Y. lipolytica -based fermentation process for astaxanthin production.

Electrochemical impedance spectroscopy technique was applied to study bilayer membranes formed with egg yolk phosphatidylcholine containing as an additional component one of two carotenoid pigments: canthaxanthin or β -carotene. The results show that both carotenoids present in the lipid membranes at relatively low concentration modify significantly electrical capacitance and electrical resistance of the membranes. Domain structures appear as a result of interactions between components within analyzed bilayers. The equilibrium of domain formation can explain the deviation from the additivity rule. This equilibrium was described by mathematical equations as well as verified experimentally. Moreover, the surface area of domains was calculated and their stoichiometry was proposed.

In this study, canthaxanthin (CTX) was produced by Dietzia natronolimnaea HS-1 using beetroot molasses as substrate and used for encapsulation in proniosome powders after extraction, with the aim of improving its stability. Proniosome powders were prepared with an equimolar ratio of span 60/cholesterol and four different carriers, namely maltodextrin, mannitol, lactose and pullulan. The properties of these formulations as both proniosomal powders and resulted niosomal dispersions were evaluated. The type of carriers had significant effects on the micrometric properties of proniosome powders which were further confirmed by the results of SEM analysis. Although light and high temperatures affected the stability of CTX drastically, but encapsulation in proniosomes retarded its degradation. Among these samples, mannitol based proniosome powder (MAPP) produced small vesicles (mean diameter=175±3nmand polydispersity index=0.28±0.02) with the highest entrapment efficiency (74.1±2.7%). MAPP provided a promising formulation to increase CTX stability especially upon storage at high temperatures (45°C).

The colour of the ventral, anal and caudal fins of Eurasian perch can range from pale yellow to intense red. Within spatially separated populations, however, individuals are usually very uniform in colour. We fed astaxanthin- and canthaxanthin-enriched dry feed to juvenile perch from a yellow-finned and a red-finned population to compare the influence of dietary carotenoids on fin colour between these two populations. In this way we wanted to test whether fin colour in perch is predominantly a phenotypically plastic trait or whether differently coloured individuals represent colour morphs. The ventral fins of perch from the red-finned population always exhibited significantly more intense redness when their feed was supplemented with either one or both carotenoid additives. Perch from both populations deposited more canthaxanthin in their ventral fins than astaxanthin, red-finned perch in particular. Yellow-finned perch probably converted canthaxanthin into β-carotene, which was the dominant carotenoid in their ventral fins, whereas the fins of red-finned perch contained only trace amounts of β-carotene. We conclude that these two populations represent colour morphs that differ fundamentally in their ability to metabolise and deposit dietary carotenoids into their ventral fins. Considering the multiple physiological functions of carotenoids, these fundamental differences in carotenoid metabolism between perch colour morphs may have far-reaching consequences for the performance of different populations, for example in their response to parasite infections.

Hen age and nutrition influence chick innate immunity. The immunomodulatory antioxidant carotenoid canthaxanthin is transferred from the hen diet to the egg. Antioxidants could protect the chick from bactericidal oxidative species produced by the immune system. Broiler breeder hen diets were supplemented with 0 (Control), 6 (Low), or 12 (High) mg/kg canthaxanthin. Chick early growth and ex vivo innate immunity were measured at 31 to 33 (Early), 45 to 47 (Mid), and 57 to 59 (Late) wk of hen age. Escherichia coli (E. coli) bactericidal capacity, phagocyte activation (number of phagocytes containing at least one E. coli), phagocytic capacity (number of phagocytes containing one or more E. coli), and oxidative burst at 1 and 4 d of age were determined. Egg and chick liver canthaxanthin and chick plasma total antioxidant capacity were measured. Differences were considered significant at P ≤ 0.05. Breeder productivity was greatest for the Low hens; diet did not affect egg yolk, albumen, or shell proportions. Egg canthaxanthin increased with maternal supplementation and plateaued after 28 days, but was not affected by hen age. Chick liver canthaxanthin increased with maternal supplementation, but decreased as hens aged. Hen diet did not affect broiler chick performance to 21 days of age. Maternal canthaxanthin at 6 mg/kg increased chick E. coli bactericidal capacity and d 1 oxidative burst; phagocytosis was unaffected. E. coli bactericidal capacity decreased as hens aged, but increased from 1 to 4 d, indicating maturation of chick innate immunity. Plasma total antioxidant capacity at d 1 increased with maternal canthaxanthin in chicks from Mid and Late hens. Canthaxanthin possesses immuno-modulatory and antioxidant properties, and hen age affected chick innate immune development. Single-comb White Leghorn hens were fed the same levels of canthaxanthin to determine the rate of incorporation into eggs. Egg canthaxanthin reached a plateau after 7 d. Canthaxanthin in the hen diet at 6 mg/kg resulted in the greatest positive effect on hen performance, with little effect on the chick.

Carotenoids provide essential nutrients, increase pigmentation, antioxidants, reproductive performance and photoprotection for Eriocheir sinensis. The ovaries, hepatopancreas, and carapace of E. sinensis are usually colorful because of carotenoids deposition. In this study, the heritability, genetic, and phenotypic correlations of carotenoids in the carapace, hepatopancreas, and ovaries of E. sinensis were investigated, and the genetic, and phenotypic correlations between color parameters and carotenoids were estimated. Mature E. sinensis females (n = 309) with from 25 full-sib families were used. The results showed that the heritabilities of total carotenoids, astaxanthin, and zeaxanthin in the carapace were 0.07 ± 0.06, 0.08 ± 0.07, and 0.04 ± 0.06, respectively. The heritabilities of total carotenoids, astaxanthin, and β-carotene in the hepatopancreas were 0.08 ± 0.12, 0.06 ± 0.09, and 0.06 ± 0.20, respectively. The heritabilities of total carotenoids, astaxanthin, lutein, zeaxanthin, canthaxanthin and β-carotene in the ovaries were 0.14 ± 0.08, 0.11 ± 0.07, 0.10 ± 0.07, 0.09 ± 0.07, 0.01 ± 0.04, and 0.10 ± 0.07, respectively. The strongest phenotypic correlations were between total carotenoids and astaxanthin in the carapace and ovaries, and the strongest genetic correlations were between total carotenoids and β-carotene in the hepatopancreas. Redness (a*) was highly correlated with astaxanthin and canthaxanthin, whereas yellowness (b*) was strongly correlated with zeaxanthin and β-carotene. These results showed that the heritabilities of carotenoids in the carapace, hepatopancreas, and ovaries of E. sinensis females are very low. Therefore, carotenoid traits may be an ineffective targets in the selective breeding programs for E. sinensis.

A 120 days trial was conducted to investigate the effect of sea squirt (Halocynthia roretzi, Drasche 1884) tunic’s carotenoid to sea-reared rainbow trout (Oncorhynchus mykiss, Walbaum 1792) growth and muscle color. Sea-rearing was done at Tongyeong sea area, Korea. Three dietary treatments, namely control (C), CT, and AT, were administered to 6 groups of fish (n = 490-520). C was given basal diet which has contained 40 mg kg−1 of astaxanthin. A further inclusion of 10 mg kg−1 canthaxanthin was added to diet of CT, while AT’s feed was supplemented with 10 mg kg−1 H. roretzi tunics carotenoids extract. The result revealed that AT has the highest final weight (1119.2 ± 82.4 g) compare to those of C (881.0 ± 121.2 g) and CT (1068.2 ± 4.3 g). The specific growth rate (SGR) of AT (1.0 ± 0.07%/day) was significantly higher than C (0.7 ± 0.22%/day) and CT (0.7 ± 0.25%/day) while the feed conversion ratio (FCR) were 1.5 ± 0.6, 1.4 ± 0.6, and 1.2 ± 0.1 for C, CT and AT respectively. The hepatosomatic index (HSI) and Viscerosomatic index (VSI) of all groups showed no significant difference (p > 0.05). The muscle color was also positively affected by the treatments, CT and AT were significantly different from C (p

In this study, canthaxanthin (CTX) was extracted from Dietzia natronolimnaea HS-1 and encapsulated in niosomes, with the aim of improving its stability. Niosomal vesicles were prepared by hydrating mixtures of various nonionic surfactants, namely tween (60, 80) and span (60, 80), with cholesterol at different surfactant/cholesterol molar ratios (1.2:0.8, 1:1 and 0.8:1.2). Results showed vesicle mean diameter in the range 159–345 nm. All formulations showed a negative surface charge and entrapment efficiency in the range 32.7–81.2%. Niosomes prepared with span 60 in combination with cholesterol at 1:1 M ratio were small and uniform in size, with high entrapment efficiency values. The influence of pH (3, 5 and 7), light and temperature (4, 25 and 40 °C) on vesicle stability was evaluated by monitoring the CTX leakage on storage. Degradation of samples was found in all conditions, especially in the presence of light. The amount of CTX retained in the niosomes decreased on storage and was strongly affected by temperature. However, the addition of cholesterol to niosome formulations decreased degradation rate of CTX as a consequence of the reduced permeability of the niosomal bilayers. Overall results of the present study demonstrate a stability enhancement of CTX in niosomes.

This study evaluated the effects of dietary canthaxanthin (CX) and 25-hydroxycholecalciferol (25-OH-D3) supplementation on the antioxidant status and tibia quality of duck breeders and newly hatched ducklings. In total, 780 female and 156 male duck breeders were randomly allotted to 2 treatments. Duck breeders were fed either a commercial diet (containing 3,000 IU/kg vitamin D3) or the same diet plus a mixture of CX (6 mg/kg) and 25-OH-D3 (0.069 mg/kg) for 40 wk. The antioxidant status of duck breeders, egg yolk, and ducklings; tibia quality of duck breeders and ducklings; and shell quality of breeder eggs were investigated. The total antioxidant capacity of breeder female liver (P = 0.028), breeder male testis (P = 0.049), egg yolk (P = 0.032), one-day-old duckling liver (P = 0.024), and one-day-old duckling yolk sac (P = 0.012) were increased by dietary supplementation of the mixture of CX and 25-OH-D3 The inclusion of CX and 25-OH-D3 decreased liver protein carbonyl of breeder females (P = 0.030), and liver malonaldehyde (P = 0.050) and protein carbonyl (P = 0.030) of breeder males. Yolk (P0.001), shank (P0.001), and yolk sac pigmentation (P0.001) of one-day-old ducklings were increased by the supplementation of the CX and 25-OH-D3 mixture. No differences (P0.05) were observed in tibia quality or eggshell quality between treatments. In conclusion, the inclusion of the mixture of CX and 25-OH-D3 in a diet sufficient in vitamin D3 increased antioxidant status but not tibia quality of duck breeders and newly hatched ducklings.

This trial studied the effects of maternal dietary vitamin premixes, and the mixture of canthaxanthin (CX) and 25-hydroxycholecalciferol (25-OH-D3) on the performance of progeny ducklings. Four maternal diets were used under a 2 × 2 factorial arrangement with 2 kinds of vitamin premixes (Regular and High; High premix had higher levels of all vitamins except K3 than the Regular premix), and with or without the addition of the mixture of CX (6 mg/kg) and 25-OH-D3 (0.069 mg/kg). Cherry Valley duck breeders (38-wk-old) were fed with corn-wheat flour-soybean meal-based diets for 8 wk, and then eggs were collected and hatched. Healthy ducklings (equal number of female and male) from each maternal group were randomly selected and received the same commercial starter (1 to 14 d) and grower (15 to 35 d) pellet diet for 35 d. Maternal High vitamin premix increased shank pigmentation (1 d, P = 0.001), BW (1 d, P < 0.001 and 14 d, P = 0.006), BW gain (1 to 14 d, P = 0.008), G:F ratio (1 to 14 d, P = 0.007), superoxide dismutase (SOD; 1 d liver, P = 0.027 and 14 d serum, P = 0.031), and total antioxidant capacity (1 d liver, P < 0.001); and decreased protein carbonyl (14 d serum, P = 0.011) of ducklings. The mixture of CX and 25-OH-D3 increased yolk pigmentation (P < 0.001); increased shank pigmentation (1 d, P < 0.001 and 14 d, P < 0.001), BW (1 d, P < 0.001), feed intake (15-35 d, P = 0.014), SOD (1 d liver, P = 0.032), and tibia ash (14 d, P = 0.010) of ducklings; and decreased malondialdehyde (P < 0.001) and protein carbonyl (P = 0.044) of yolks, and malondialdehyde (14 d serum, P < 0.001) of ducklings. In conclusion, either maternal High vitamin premix or maternal supplementation of the CX and 25-OH-D3 mixture improves growth performance and antioxidant status of ducklings.

The aim of this work was to undertake an extensive study on the bioactive compounds and inhibition of the α-amylase of Litopenaeus vannamei and Ucides cordatus residues and report the effect of gastrointestinal digestion on the phenolic content and antioxidant activity of its extracts. The carotenoid astaxanthin was quantified in all the residues, while canthaxanthin was identified only in L. vannamei (0.240 mg/g). Naringenin was the major phenolic compound quantified in L. vannamei (17,389.74 μg/g) and U. cordatus (171.45 μg/g), while the succinic acid was the only organic acid detected. The α-amylase inhibitory activity was evaluated and the U. cordatus residue ethanolic extract exhibited the highest inhibitory activity (50%). Approximately 8.14–54.52% of phenolic compounds were bioaccessible. FRAP and ORAC assays showed an increase after the gastrointestinal process. To the best of our knowledge, for the first time, the bioaccessibility of these residues was reported in association with antidiabetic effects. Thus, the L. vannamei and U. cordatus residues can be potentially explored for biotechnological functional processes.

Coelastrella astaxanthina Ki-4, a eukaryotic microalga belonging to the family Scenedesmaceae, survives for long periods under severe photo-oxidative stress conditions associated with the accumulation of water-soluble astaxanthin-binding glycoprotein, named AstaP. It is a novel carotenoprotein in photosynthetic organisms and is involved in photo-oxidative stress protection, but its expression profile during cell survival and relationship with the biosynthesis of the cofactor astaxanthin are almost unknown. In this study, based on the analysis of photosynthesis during cell survival under photo-oxidative stress conditions, we classified the recovery periods of photosynthesis into the following three stages: recovery, tolerance, and cyst stages. Although C. astaxanthina Ki-4 promptly decreased the activity of photosynthesis after the start of photo-oxidative stress treatment, the activity recovered in the early recovery stage, where the expression of the transcript encoding AstaP was significantly upregulated. In the tolerant stage, red-coloration and enlargement of cells were gradually increased, and the accumulation of the AstaP protein was also significantly increased. C. astaxanthina Ki-4 cells presented a large amount of lutein before the stress treatment, which was decreased with the gradual increase in secondary carotenoids, such as canthaxanthin, adonixanthin, and astaxanthin. Although astaxanthin was quantified to be almost equal to that of the other secondary carotenoids, astaxanthin was detected as the main carotenoid binding to AstaP. These results suggest that AstaP preferentially binds to astaxanthin in vivo and contributes to photo-oxidative stress protection mainly in the tolerance stage.

Echinenone and canthaxanthin are important carotenoid pigments with food and industrial applications. Biosynthesis of echinenone and/or canthaxanthin is catalyzed by β-carotene ketolase (CrtO), with β-carotene as the substrate. In this study, we generated transgenic Nostoc sp. PCC 7120 overexpressing a heterologous crtO gene from Nostoc flagelliforme and evaluated the productivity of both pigments. Normal (BG11 medium, 30 °C) and osmotic stress (BG11 medium supplemented with 0.4 M mannitol, 30 °C) conditions were used for cultivation. As compared to control strain, production of echinenone and canthaxanthin in transgenic strain were respectively increased by more than 16 % and 80 %, under either normal or osmotic stress conditions. Especially upon the stress condition, higher proportion of echinenone and canthaxanthin in total pigments was achieved, which should be beneficial for downstream separation and purification. In addition, transgenic strain showed drought tolerance and could revive from desiccation treatment after rewetting. Thus, this study provided technical clues for production of both pigments in engineered cyanobacteria as well as for cyanobacterial anhydrobiotic engineering.

Ethnopharmacological relevance The multidrug-resistant (MDR) pathogen, Mycobacterium tuberculosis, still remains as one of the major threat to mankind, despite the availability of a live attenuated vaccine and effective antibiotics. Marine microalgae, at all times, act as a key resource for valuable therapeutic compounds with limited side effects. Aim of the study The present explorative attempt is to isolate the biomolecules of pharmacological importance from the marine microalgae, Chlorella vulgaris, and to evaluate its effect on the ever dreadful disease, Tuberculosis. The study is also aimed to develop an economically feasible methodology for by-products extraction from microalgae. Materials and methods Fatty acids-carotenoid complexes (FACC), namely, FACC-1 (red oil) and FACC-2 (brown oil) were isolated, in addition to lipid and lutein from the Chlorella Growth Factor (CGF, a protein fraction enriched with vitamins, minerals and carbohydrates)-extracted spent biomass through column chromatography. Results FACC-1 is a complex of fatty acids such as oleic and linoleic acids, and carotenoids such as canthaxanthin and neoxanthin. FACC-2 is a complex of oleic, linoleic and linolenic acids and carotenoids (cryptoxanthin and echinenone). Initial screening for evaluation of minimum bactericidal concentration (MBC) of FACC-1 and -2 was performed against Mycobacterium tuberculosis strains such as H37Rv, SHRE sensitive clinical isolate and SHRE resistant clinical isolate. MBC was noted at 10 μg/mL by FACC-1 and at 5 μg/mL by FACC-2, determined using colony forming and Lucipherase Reporter Mycobacteriophages (LRP) assay. Testing in the PAN sensitive isolates indicated that the MBC was noted at 5 μg/mL by FACC-1 and at 2.5 μg/mL by FACC-2. Complete inhibition (100%) was observed at 100 μg/mL by FACC-1 and at 50 μg/mL by FACC-2. Testing of FACC-1 and FACC-2 individually as well as in combination on two different types of MDR strains confirmed the efficacy of the algal oils, wherein in MDR-strain 1, FACC-1 revealed 50% inhibition at 10 μg/mL, while FACC-2 exhibited the same at 5 μg/mL. Conversely, in the case of MDR strain-2, MBC of FACC-1 was at 500 μg/mL and MBCof FACC-2 to be at 250 μg/mL. No significant synergistic effect was observed on combining both the oils. Conclusion The study signifies the development of a potent therapeutic agent comprising of a complex of anti-TB agent (fatty acids) and antioxidants (carotenoids) from the CGF-extracted spent biomass of C. vulgaris.

Light is a pivotal environmental factor that affects the growth and productivity of photosynthetic organisms. Microalgae have evolved complex photoprotective mechanisms to circumvent damage from high light. Nannochloropsis produce approximately 4–5% eicosapentaenoic acid (EPA) of dry cell weight (dwt) under favorable growth conditions, and accumulate triacylglycerol (TAG) at up to 60% of dwt under nutrient-depletion and high light intensities. Nannochloropsis is becoming a strong research model for oleaginous microalgae and an excellent candidate for biofuel production. To study the photoprotective mechanisms of Nannochloropsis, proteomic and physiological dynamics were tested under different light intensities. When exposed to high light stress N. oceanica IMET1 cells showed a 45% and 38% decrease in total protein and sugar content, respectively, and a 44% increase in total lipid content; the growth of cells was not affected. Cell pigment content varied substantially: chlorophyll a and violaxanthin concentrations decreased by >50%, while β-carotene, zeaxanthin, astaxanthin, and canthaxanthin increased transiently by >2-fold. Isobaric tags for relative and absolute quantification (iTRAQ) was used to label samples, and 452 proteins were identified from tandem mass spectrometry data. In response to high light stress, 150 of these proteins were significantly up-regulated and 58 were significantly down-regulated. The proteins were involved in pathways that include photosynthesis, pyruvate metabolism, and fatty acid biosynthesis. Results also indicate that photochemical adjustments in carbon metabolism, in particular, glycolysis, the Calvin cycle, and the citric acid (TCA) cycle, were activated to divert more acetyl-CoA towards carotenoid biosynthesis. This could be to scavenge reactive oxygen species to alleviate photodamage. A regulatory photoprotective model for N. oceanica IMET1 was proposed, which includes strategies of down-regulating light-harvesting antenna proteins, up-regulating oxidases, enhancing de-epoxidation within the xanthophyll cycle, accumulation of antioxidants, modulation of photosynthetic apparatus, and repartitioning of photosynthetic carbon into storage carbon.

This study was conducted to determine the effect of dietary supplement of bacterial lycopene (BL) produced by Escherichia coli on the egg quality and blood characteristics of laying quails. The antioxidant activity measurement showed that BL exhibited 100% 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging capacity at a concentration of 4.65 μg/ml, which was more effective than butylated hydroxytoluene (BHT) and commercial lycopene (CL). Moreover, seven dietary groups of laying quails consisting of 10 100-day-old quails (Coturnix coturnix japonica) each were fed with the basal diet supplemented with BL, CL or canthaxanthin (CA) for 4 weeks. Consequently, the triglyceride content of yolk was significantly lower in the group with BL and CL supplement. The serum malondialdehyde (MDA) level of the BL- and CA-supplemented groups at 18 mg/kg was lower than the control group. In conclusion, BL has a high antioxidant activity and is promising as a feed additive in the diet of laying quails.

The profile of the three classes of pigments (carotenoids, chlorophylls and phycobiliproteins) and the peroxyl radical scavenger capacity of extracts from microalgae Phormidium autumnale were determined. Twenty-four carotenoids, three phycobiliproteins and two chlorophylls were identified. The major carotenoids of biomass were all-trans-β-carotene (225.44 μg·g− 1), all-trans-lutein (117.56 μg·g− 1) and all-trans-zeaxanthin (88.46 μg·g− 1). Furthermore, characteristic carotenoids in cyanobacteria such as echinenone (79.07 μg.g− 1), myxoxanthophyll (18.83 μg.g− 1) and canthaxanthin (1.89 μg·g− 1) were found. The chlorophyll a (2.700 μg·g− 1) and C-phycocyanin (2.05 × 105 μg·g− 1) were predominant pigments in the other fractions of color compounds from biomass. The carotenoid and chlorophyll extracts were shown to be potent scavengers of peroxyl radical, being almost 28 and 85 times more potent α-tocopherol respectively, and for phycobiliproteins, the antioxidant capacity was 274 μmol trolox·g− 1 (dry wt).

A feed trail was conducted to evaluate the efficiency of Streptocephalus simplex as a live feed in freshwater ornamental fish culture. The efficiency of live feed was compared with that of artificial/pellet diet to determine the growth rate biochemical parameters and carotenoid concentration of Carassius auratus for a period of 45 days. As a result the proximate composition on the S. simplex indicates that they are rich in protein, lipids, essential amino acids and fatty acids. Availability of these growth factors was perfectly reflected on the successful growth rate of C. auratus. Moreover, presence of carotenoids viz., astaxanthin (36.4 ± 2.4), canthaxanthin (23.6 ± 1.7), and β-carotene (1.7 ± 0.6) has improved the intensity of the skin color of commercially important ornamental fish C. auratus after feeding with S. simplex.

A novel carotenoid producing strain of Dietzia maris NIT-D was isolated from soil and cultured in shake flasks, employing sugarcane bagasse hydrolysate (SCBH) as the carbon source, under optimized conditions. The pigment was identified as trans -canthaxanthin. The purified pigment extracts were submitted to temperature and pH stability analysis and results obtained were fitted into the fractional conversion model and the first order kinetic model respectively. Canthaxanthin showed maximum stability at 30 °C and at a near-neutrality pH value of 6.5. The pure pigment extract was introduced in 2 model systems and stored at different temperatures and illumination conditions for 32 days. Storage studies showed that canthaxanthin was sensitive to light and temperature of storage. Maximum stability was observed when purified canthaxanthin was stored in dark at 4 °C. Results also showed that canthaxanthin was more stable in Aloe vera solution than in bovine serum albumin solution. The modified logarithmic model aptly justified the pigment stability under storage. Canthaxanthin, produced from low-cost agro-industrial waste, may be used as colorant under mild process conditions.

Elucidating the processes that create species differences is a central goal of evolutionary biology. The Northern Flicker (Colaptes auratus) exists as two well-differentiated subspecies groups in North America, the Yellow-shafted (auratus group) and Red-shafted Flickers (cafer group), which differ strikingly in the color of the underside and rachises of flight feathers, and of malar and nuchal patches. We investigated the physiological basis of these conspicuous phenotypic differences by identifying and quantifying the pigments involved. The yellow feathers of auratus contained carotenoids commonly found in nature (lutein, β-cryptoxanthin, zeaxanthin and β-carotene). The orange to red shafts/vanes of cafer and hybrids contained these carotenoids as well as mono- and diketo-carotenoids (notably adonirubin, α-doradexanthin, canthaxanthin, astaxanthin), representing oxygenated products at carbon C4(4') of the carotenoids present in auratus. Oxygenation of feather carotenoids at C4(4') correlated closely with shaft/vane redness. Carotenoid hydroxylation at C3(3') and the proportion of carotenoids with ε end-rings also varied with color and belie differences in the activity of several carotenoid-modifying enzymes between the two subspecies groups. Curiously, occasional yellow feathers in red-shafted individuals had the carotenoids of auratus, hence the differences are not constitutive in cafer, underscoring regulatory differences. The red malar stripe of cafer, the black malar stripe and red nuchal patch of auratus all contained similar types and amounts of carotenoids, mostly 3-hydroxy-4-keto-carotenoids. The biochemical differences between two strongly differentiated forms we uncovered shed light on how plumage coloration can change over evolutionary time and point to further avenues of research.

Liposomes have become an attractive alternative to encapsulate carotenoids to improve their solubility, stability and bioavailability. The interaction mechanism of carotenoid with lipid bilayer is one of the major concerns in improving the delivery efficiency of liposomes. In this study, the microstructure and carotenoid encapsulation efficiency of liposomes composed of native phospholipid (egg yolk phosphatidylcholine, EYPC) and nonionic surfactant Tween 80 were investigated by atomic force microscopy, dynamic light scattering, and Raman spectroscopy, respectively. Subsequently, the effects of carotenoid incorporation on the physical properties of liposomal membrane were performed by Raman spectroscopy, fluorescence polarization, and electron paramagnetic resonance. Results showed that the incorporation of carotenoids affected the liposomes morphology, size and size distribution to various extents. Analysis on the Raman characteristic peaks of carotenoids revealed that lutein exhibited the strongest incorporating ability into liposomes, followed by β-carotene, lycopene, and canthaxanthin. Furthermore, it was demonstrated that carotenoids modulated the dynamics, structure and hydrophobicity of liposomal membrane, highly depending on their molecular structures and incorporated concentration. These modulations were closely correlated with the stabilization of liposomes, including mediating particle aggregation and fusion. These findings should guide the rationale designing for liposomal encapsulation technology to efficiently deliver carotenoids in pharmaceutics, nutraceuticals and functional foods.

The low bioaccessibility of carotenoids is currently a challenge to their incorporation in pharmaceutics, nutraceuticals and functional foods. The aim of this study was to evaluate the modulating effects of liposome encapsulation on the bioaccessibility, and its relationship with carotenoid structure and incorporated concentration. The physical stability of liposomes, lipid digestibility, carotenoids release and bioaccessibility were investigated during incubation in a simulated gastrointestinal tract. Analysis on the liposome size and morphology showed that after digestion, the majority of particles maintained spherical shape with only an increase of size in liposomes loading β-carotene or lutein. However, a large proportion of heterogeneous particles were visible in the micelle phase of liposomes loading lycopene or canthaxanthin. It was also found that the release of lutein and β-carotene from liposomes was inhibited in a simulated gastric fluid, while was slow and sustained in a simulated intestinal fluid. By contrast, lycopene and canthaxanthin exhibited fast and considerable release in the gastrointestinal media. Both carotenoid bioaccessibility and micellization content decreased with the increase of incorporated concentration. Anyway, the bioaccessibility of carotenoids after encapsulated in liposomes was in the following order: lutein>β-carotene>lycopene>canthaxanthin. Bivariate correlation analysis revealed that carotenoid bioaccessibility depended strongly on the incorporating ability of carotenoids into a lipid bilayer, loading content, and nature of the system.

An Acutodesmus microalga of the Scenedesmaceae family isolated from the Algerian Sahara was characterized for its ability to produce lipids, fatty acids (FA) and carotenoids under nitrate starvation, osmotic stress and a varying level of oxidative stress. The FA produced by this strain isolated from an environment typified by extreme heat showed a lower degree of unsaturation than those of other Scenedesmus which have been isolated from cold or temperate water environments, with no unsaturated C16 FA and more than 92% of the FA profile being comprised of FA with less than three unsaturated bonds. According to the degree of unsaturation and the cetane number, the FA profile from this strain is highly favorable for biofuel production. Lipogenesis and carotenogenesis were easily reversible upon removal of the stress. These results constitute an advance in developing strains suitable for industrial-scale production of biofuels.

A fundamental study on the phase-solubility, storage stability and antioxidant activity of the inclusion complex of 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) with canthaxanthin (CTX) biosynthesized by Dietzia natronolimnaea HS-1 in a continuous bioreactor was designed. A variety of in vitro chemical methods including reducing power (RP), nitrite-scavenging activity (NSA), and 1,1-diphenyl-2-picryl-hydrazyl (DPPH), 2,2′-azinobis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) and hydroxyl radicals scavenging capacities was used to determine antioxidant activities of the CTX and CTX/HP-β-CD complex. Results revealed that the apparent stability constant of the inclusion complex was 669 M−1 in a 1:1 stoichiometric ratio. The complexation of CTX with HP-β-CD significantly improved its water solubility and storage stability. An increased dose-dependent manner was found for the NSA and RP values of the CTX and CTX/HP-β-CD complex. The CTX/HP-β-CD complex showed higher scavenging capacity than native CTX against DPPH, ABTS and hydroxyl radicals. It can be used as a promising strategy to improve the food application of CTX.

Secondary carotenoids are high-valued anti-oxidants which can be produced by some algae when exposed to an environmental stress (e.g. nutrient deprivation, high light intensities). To this end, we characterized the stress-induced carotenoid production of a new microalgal strain, Dactylococcus dissociatus MT1, which was isolated from the Sahara Desert of Algeria. Nitrate starvation, oxidative stress and varying light intensities were applied to determine the effect of illumination on carotenogenesis. Canthaxanthin was the main secondary carotenoid and light intensity had an important influence on the rate of its accumulation. The addition of NaCl also enhanced canthaxanthin production while nitrate depletion had more of an effect on lipid production. However, these two stresses in combination synergistically increased the production of both. Our results represent a step toward the development of strains suitable for secondary carotenoid production at the industrial scale.

Dunaliella viridis is a green microalga containing β-carotene, which is the precursor of astaxanthin, the most active antioxidant in Haematococcus pluvialis. Two key enzymes of H. pluvialis, β-carotene hydroxylase (CRTR-B) and β-carotenoid ketolase (BKT), are required for converting β-carotene to astaxanthin in D. viridis via the astaxanthin biosynthetic pathway. Considering the location of β-carotene in the chloroplast of D. viridis, the two modified genes encoding BKT and CRTR-B in H. pluvialis were integrated via homologous recombination into the chloroplast genome, in this study. In the chloroplast, the homologous recombination vector pMD-bkt-crtr (16S-TrnA-atpA-bkt-crtR-B-rbcL-psbA-bar-TrnI-23S), bkt and crtR-B were regulated by the atpA promoter in a polycistron. The presence of astaxanthin in the D. viridis mutant expressing BKT and CRTR-B was verified using high performance liquid chromatography (HPLC), and the maximum content of total astaxanthin and canthaxanthin after high light induction were 77.5 ± 7.7 and 50.1 ± 0.8 μg g−1 in dry weight, respectively. Our results indicate that D. viridis can be used as a cell factory for astaxanthin production.

In this study, two kinds of functional dairy products were developed using microencapsulated natural canthaxanthin (CX). Microbial CX was produced and then microencapsulated in Alginate (Alg) and Alg-High methoxyl pectin (HMP) through O/W/O multiple emulsion/external gelation method. The microcapsules were used as colorant and antioxidant agents and their influences were evaluated on antioxidant activity, color and apparent viscosity of final products during storage. Control samples (formulated with free CX) showed the highest antioxidant activity and color at day 0, but these parameters decreased during storage (from 23.07 ± 0.12 to 5.74 ± 0.15 and from 7.61 ± 0.01to 2.01 ± 0.01 in flavored milk (M-B) and from 22.22 ± 0.02 to 2.15 ± 0.17 and from 7.02 ± 0.04 to 1.08 ± 0.09 in flavored fermented milk (FM-B) for antioxidant activity and color (a*), respectively). In treatments with microparticles, the decrease in antioxidant activity was slower and even in flavored milks with Alg-HMP microcapsules (M-Alg & HMP) differences were not significant (from 23.03 ± 0.21 to 20.51 ± 0.13 after 7 days storage). Alg-HMP microcapsules led to treatments with acceptable characteristics. In conclusion, encapsulated CX by Alg-HMP could be satisfactorily used as a coloring agent as well as a functional ingredient in flavored milk and flavored fermented milk drink.

Pigment-depletion in the fillets of farmed Atlantic salmon (Salmo salar) arises after periods of elevated water temperatures with voluntary starving. This study tested the effects of dietary pre-loading with different pigment carotenoids (astaxanthin and/or canthaxanthin) combined with two α-tocopherol levels (normal and high: 500 and 1000 mg/kg, respectively) on pigment-depletion in vivo in Atlantic salmon after four weeks of challenge. We also tested whether oxidative stress manifested as an underlying depletion mechanism. Carotenoid levels in whole fillet homogenates were not decreased significantly post-challenge but fillet α-tocopherol concentrations were increased significantly in contrast to decreased oxidative stress indices. However, image analysis revealed localised fillet pigment-depletion following all dietary treatments. These data imply that localised pigment-depletion was not prevented by pre-loading of the fillet with different carotenoid-types/mixtures and increased of α-tocopherol levels from normal to high, respectively. Further, we suggest that oxidative stress might not facilitate pigment-depletion in vivo.

Recent analyses of the orange, red, and purple plumages of cotingas (Cotingidae) and broadbills (Eurylaimidae) revealed the presence of novel carotenoid molecules, suggesting that the diversity of pigments and the metabolic transformations they undergo are not yet fully understood. Two Old World orioles, the Black-and-Crimson Oriole Oriolus cruentus, and the Maroon Oriole Oriolus traillii, exhibit plumage colors that are similar to those of some cotingas and broadbills. To determine if these oriole plumage colors are produced by the same carotenoids or with other molecules, we used high-performance liquid chromatography (HPLC), mass spectrometry, and chemical analyses. The data show that the bright red feathers of O. cruentus contain a suite of keto-carotenoids commonly found in avian plumages, including canthaxanthin, adonirubin, astaxanthin, papilioerythrinone, and α-doradexanthin. The maroon feathers of O. traillii were found to contain canthaxanthin, α-doradexanthin, and one novel carotenoid, 3',4-dihydroxy-ε,ε-carotene-3-one, which we have termed "4-hydroxy-canary xanthophyll A." In this paper we propose the metabolic pathways by which these pigments are formed. This work advances our understanding of the evolution of carotenoid metabolism in birds and the mechanisms by which birds achieve their vivid plumage colorations.

Canthaxanthin (CXN) is a red pigment, which is broadly used in broiler chickens for skin pigmentation, in laying hens for the coloration of egg yolks and in poultry breeders for improving the antioxidant status of eggs. In order to investigate the safety of this feed additive under conditions of an accidental oversupply, studies in all target poultry categories were performed, comparing a non-supplemented control to treatments with the respective recommended dietary supplementation of CXN and a ten times overdose of the recommended CXN level. Performance, mortality and a number of hematological and blood biochemical variables as well as post-mortem evaluations were taken as parameters to assess the effects of CXN overdosing. In broilers performance was not influenced by treatment with CXN at 25 or 250 mg/kg feed. The hematological traits of the CXN groups were either not different from the control or remained within the normal physiological range. Concentration of CXN in blood plasma increased (P

For the first time in this study, the antioxidant effects of pigment produced by Dietzia natronolimnaea HS-1 in terms of 1,1-diphenyl-2-picryl-hydrazyl (DPPH), 2,2′-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and hydroxyl radicals scavenging capacities, reducing power (RP) and nitrite scavenging activity (NSA) in batch, fed-batch and continuous cultivation systems were compared. HPLC analysis showed that this bacterium accumulated canthaxanthin (CTX) as the predominant carotenoid. Continuous cultivation was found to be the best bioprocess for extracting biomass dry weight (BDW, 12.65 g/L), total carotenoid (21.52 mg/L) and CTX (19.58 mg/L) with the favorable antioxidant characteristics when compared to the batch and fed-batch cultivations. The synthesized CTX in this culture effectively scavenged DPPH, ABTS and hydroxyl radicals, and higher concentrations of this pigment indicated potent RP and NSA in a dose-dependent manner. The antioxidant activity in the DPPH assay was strongly correlated with ABTS radical-scavenging ( r 2 = 0.867), NSA ( r 2 = 0.906) and RP ( r 2 = 0.860) values ( p

Four aerial microalgae were isolated from the surface of rocks in mountainous districts of Japan and identified as Scenedesmus sp. KGU-Y002, Scenedesmus sp. KGU-D002, and Coelastrella sp. KGU-H001 of the class Chlorophyceae and Vischeria helvetica KGU-Y001 of the class Eustigmatophyceae based on 18S rDNA analysis. Algal carotenogenesis was enhanced by increasing the light intensity from 40 to 214 μmol photons m − 2 s − 1 , with more or less decrease in the total chlorophyll content. Culture of these microalgae under high-light conditions resulted in production of astaxanthin (free and esters), adonixanthin (free and esters), lutein, canthaxanthin, and β-carotene as the major carotenoids. Under high-light culture conditions, strains KGU-Y002, KGU-D002, KGU-H001, and KGU-Y001 accumulated 5.75, 10.45, 2.60, and 11.50 mg g − 1 dry weight cells (dwc) of total carotenoids when the total chlorophyll contents were 3.51, 5.88, 2.91, and 7.17 mg g − 1 dwc, respectively. The astaxanthin produced might primarily be synthesized from β-carotene via accumulation of zeaxanthin and adonixanthin in strains KGU-Y002, KGU-D002, and KGU-H001. Strain KGU-Y001 was found to accumulate astaxanthin and violaxanthin with large amounts of β-carotene. These results revealed that the biosynthesis pathways for astaxanthin in these isolates were significantly different from those of astaxanthin in green microalgae.

The physical stability of the ultrasonically prepared emulsions containing canthaxanthin (CX) produced by Dietzia natronolimnaea HS-1 strain was maximized using a face central composite design (FCCD) of response surface methodology (RSM). The linear and interaction effects of main emulsion components (whey protein isolate (WPI, 0.4-1.2 wt%), psyllium husk gum (PHG, 1.5-4.5 wt%) and coconut oil (CO, 5-10 wt%)) on the stability were studied. The density, turbidity and droplet size of emulsions were also characterized to interpret the stability data. A significant second-order polynomial model was established (p0.0001). Maximum stability of 98.8% was predicted at the optimum levels of formulation variables (WPI concentration 1.20 wt%, PHG content 3.30 wt%, CO concentration 5.43 wt%). The results also demonstrated that CO and WPI concentration had greater effect on the droplet size and density values, whereas the PHG:WPI ratio had a rather greater effect on the turbidity values.

CrtW and CrtO are two distinct non-homologous β-carotene ketolases catalyzing the formation of echinenone and canthaxanthin. CrtO belongs to the CrtI family which comprises carotene desaturases and carotenoid oxidases. The CrtO protein from Synechocystis sp. PCC 6803 has been heterologously expressed, extracted and purified. Substrate specificity has been determined in vitro. The enzyme from Synechocystis is basically a mono ketolase. Nevertheless, small amounts of diketo canthaxanthin can be formed. The poor diketolation reaction could be explained by the low relative turnover numbers for the mono keto echinenone. Also other carotenoids with an unsubstituted β-ionone ring were utilized with low conversion rates by CrtO regardless of the substitutions at the other end of the molecule. The CrtO ketolase was independent of oxygen and utilized an oxidized quinone as co-factor. In common to CrtI-type desaturases, the first catalytic step involved hydride transfer to the quinone. The stabilization reaction of the resulting carbo cation was a reaction with OH(-) forming a hydroxy group. Finally, the keto group resulted from two subsequent hydroxylations at the same C-atom and water elimination. This reaction mechanism was confirmed by in vitro conversion of the postulated hydroxy intermediates and by their enrichment and identification as trace intermediates during ketolation.

Canthaxanthin has significant commercial value due to its use as an antioxidant and feed additive in aquaculture and poultry farms. The biological production of high-value carotenoids, such as canthaxanthin, represents a significant challenge. Presented here is an Escherichia coli bioprocess, which includes the recombinant production of a strain, a novel medium and a fermentation process, for the efficient biosynthesis of canthaxanthin. The chromosomal overexpression of the E. coli genes Idi , Dxs and Dxr increased the carbon flux into the plasmid-based canthaxanthin biosynthetic pathway, achieving a total carotenoid productivity of 11.7 mg/g (91% canthaxanthin). The development of a novel culture medium increased the productivity 2.9-fold to 78.2 mg/L total carotenoids. This high-titer platform was subsequently employed for the analysis of mutations known to be advantageous to carotenoid biosynthesis, providing the first such evaluation in a high titer background. This demonstrated that thee increased expression of IspB or the deletion of PykF , PykA or YtjC improved the total carotenoid yield, whereas the increased expression of Pps and Ppc , was not improve productivity. This analysis resulted in an increase in the carotenoid yield to 16.1 mg/g. The use of 1 L lab-scale fermentations allowed for further improvements in productivity, and 170 mg/L total carotenoids was obtained.

The large amount of fish feed involved in salmon aquaculture results in high nutrient loading to the surrounding environment. The near-field effects of this loading are well documented but the full zone of influence, or far-field effect, remains poorly understood. We investigated the potential of the carotenoid canthaxanthin, a common additive in farmed Atlantic salmon diets, as a biochemical tracer to identify this zone of influence in two benthic invertebrate species that are locally abundant around salmon farms: the blue mussel Mytilus edulis (or Mytilus trossulus ), a suspension feeder, and the green sea urchin Strongylocentrotus droebachiensis , an omnivorous grazer. To measure persistence of canthaxanthin in the digestive gland of mussels or the gonad of sea urchins, both species were individually fed three levels of salmon feed (6, 13, 26 mg d − 1 for mussels; 70, 150, 300 mg d − 1 for sea urchins) for 13 d to measure pigment uptake rates, followed by a non-pigmented diet for 7 d to measure pigment loss rates. Mussels exhibited a relatively rapid uptake of canthaxanthin (1 to 3 d), which subsequently declined to zero within 3 d following cessation of the pigmented diets. The sea urchins exhibited slower initial uptake (4 to 10 d) and the pigment signal lasted up to 46 d, suggesting retention of canthaxanthin. To examine the scale of dispersion of feed-derived particulate material in nature, canthaxanthin uptake by sea urchins was measured at fixed intervals along a transect extending 1 km from a salmon cage in Passamaquoddy Bay, New Brunswick, Canada. Pigment concentration in the gonad dropped from ~ 5 to 0.5 μg g − 1 within the first 100 m from the cage and remained at this low level along the remainder of the transect, likely reflecting low background levels of salmon farm-derived particles within the bay. Our study demonstrates the potential of canthaxanthin as an organic tracer for salmon aquaculture, and the use of blue mussel digestive gland for short-term detection and sea urchin gonad for long-term detection, in accordance with the rapid ingestion and nutrient storage functions of the respective tissues.

The bacterium Dietzia natronolimnaea HS-1 is biotechnologically important due to its ability to biosynthesis the pigment canthaxanthin (CX). This study presents a promising direction to attain to the highest feasible levels in biomass dry weight (BDW), total carotenoid (TC) and CX by using the selection of superior mutant type in combination with optimization of nutrient medium components. The mutant strains were obtained using UV irradiation and ethyl methane sulfonate (EMS) treatment. Results showed that the mutants induced by EMS had higher survival and growth rates compared to UV mutants. EMS was effective mutagenic agent for strain improvement of D. natronolimnaea HS-1 for enhanced CX productivity. Also, preliminary batch experiments were carried out to achieve the suitable conditions for CX production analysis and found that d -glucose, mannose and Fe 3+ have significant influences on the CX biosynthesis and microorganism growth. The medium formulation in a batch bioreactor was optimized by a central composite design-response surface methodology (CCD-RSM). Second-order empirical equations with high R 2 (0.989–0.996) between the responses and independent variables were derived. The optimum conditions for the maximum of BDW (9.95 g/l), TC (7.67 mg/l) and CX (7.10 mg/l) amounts were: d -glucose (25 g/l), mannose content (15.12 g/l) and Fe 3+ concentration (36.77 ppm).