Manipulation of the Regulatory Genes ppsR and prrA in Rhodobacter sphaeroides Enhances Lycopene Production
12
Citation
49
Reference
10
Related Paper
Citation Trend
Abstract:
Rhodobacter sphaeroides is a non-sulfur purple bacterium with great metabolic versatility, capable of producing a variety of valuable compounds that include carotenoids and CoQ10. In order to enhance lycopene production, we deleted the photosynthetic gene cluster repressor ppsR from a lycopene-producing Rb. sphaeroides strain (RL1) constructed in a previous study to break the control of carotenoid synthesis by the oxygen level. Also, lycopene production was further increased by overexpression of the activator prrA. The superior lycopene producer DppsR/OprrA thus obtained had a high growth rate and a lycopene production of 150.15 mg/L with a yield of 21.45 mg/g dry cell weight (DCW) under high oxygen conditions; these values were ≥6.85-fold higher than those of RL1 (19.13 mg/L; 3.32 mg/g DCW). Our findings indicate that elimination of oxygen repression led to more efficient lycopene production by DppsR/OprrA and that its increased productivity under high oxygen conditions makes it a potentially useful strain for industrial-scale lycopene production.Keywords:
Rhodobacter sphaeroides
Bacterial strain
Abstract Lycopene is the major carotenoid in tomatoes. Tomatoes contain a matrix of many bioactive components, including vitamin C, vitamin E, other carotenoids (a‐, β‐, γ‐ carotene, lutein), and flavonoids. Their synergistic interactions, when used in combination, may be responsible for the observed beneficial effects of tomato‐based products. This study investigated the synergistic antioxidant activity of lycopene in combination with β‐carotene, vitamin E, and lutein. A liposome system was used to test the synergistic antioxidant activity. The carotenoid mixtures were more efficient in protecting liposome from oxidation than the individual carotenoid. Mixtures of lycopene and vitamin E appear to have the greatest synergistic antioxidant activity.
beta-Carotene
Carotene
Cite
Citations (89)
Bacterial conjugation
Cite
Citations (7)
The most abundant carotenoids present in tomato-based products were taken into account. Several samples coming from Italian stores have been analysed by using an RP – HPLC method. These products show a free carotenoids content proportional to the intensity of the manufacturing processes to which their are subjected. Among the carotenoids lycopene isomerises in various cis forms under different chemical – physical conditions. The lycopene antioxidant activity appears to be related to its trans – cis isomerisation degree, and the stability and the relative abundance of the isomers were investigated by applying heating and illumination. The cooking process seems to increase the total lycopene availability, whereas a prolonged exposure to a light source appears to be the best way to obtain the cis isomers. β-carotene is partially subjected to degradative processes, and do not shows an appreciable isomerisation degree under the same conditions.
Cite
Citations (0)
Carotenoids analysis is complicated by their tendency to react with radical species, resulting in oxidative breakdown and isomerization during extraction. Hence, analysis methods should be rapid and avoid unnecessary exposure to high temperature, acids, and so on. The aim of this work to estimate carotenoid contents of processed tomato products non-destructively. The mean values obtained by visible and near-infrared Vis/NIR spectroscopy and by high performance liquid chromatography (HPLC) for eight carotenoid contents (ß-carotene, 5-cis lycopene, 13-cis lycopene, 9-cis lycopene, all-trans lycopene, zeaxanthin, lycoxanthin and total carotenoids) in four processed tomato products from five different brands were compared. The carotenoid contents were measured using HPLC, and these results were then used to develop partial least squares regression (PLSR) models to predict carotenoid components from Vis/NIR spectra of the same samples. A good correlation was found between HPLC measurements and the Vis/NIRs (590-790 nm) predictions for ß-carotene (RP2= 0.88), 9-cis lycopene (RP2= 0.86), total carotenoids (RP2= 0.84), 13-cis lycopene (RP2= 0.83), 5-cis lycopene (RP2=0.80), zeaxanthin (RP2= 0.80) to passable for all-trans lycopene (RP2= 0.70), but there was only a poor correlation (RP2= 0.20) for the lycoxanthin component. The overall results indicated that Vis/NIRs could be applied to assess carotenoid contents of different processed tomato products.
Cite
Citations (19)
Rhodobacter sphaeroides
Rhodospirillaceae
Strain (injury)
Rhodospirillales
Poly-3-hydroxybutyrate
Bacterial strain
Rhodobacter
Cite
Citations (0)
Previously, Rhodobacter sphaeroides strain HJ was isolated to obtain a purple nonsulfur bacterium with the ability to produce high levels of hydrogen from acetate. However, the genome of this strain has not been previously sequenced. Therefore, the complete genome sequence of R. sphaeroides strain HJ is presented in this report.
Rhodobacter sphaeroides
Rhodospirillaceae
Rhodospirillales
Strain (injury)
Purple bacteria
Bacterial strain
Cite
Citations (1)
Diets containing plant-food, with a wide variety of phytochemical compounds such as flavonoids, carotenoids, monoterpens, isothiocyanates, and phytosterols, have been associated with health benefit effects. Carotenoids are natural pigments from plants and micro-organisms. Although the nutritional importance has been confined to those possessing pro-vitamin A activity, nowadays other carotenoids such as lycopene, have also emerged as nutritional compounds according to their biological properties. Lycopene is present in tomato, watermelon, papaya, apricot and pink grapefruit, providing tomato and tomato products the highest content in the diet. The health effects of lycopene derived from its free radical scavenging capacity, which is higher to those evaluated in other carotenoids, such as has been described in in vitro and in vivo studies. The epidemiological studies implicate the lycopene with the prevention of cardiovascular diseases and epithelial cancers. This review summarizes the importance of lycopene in the diet, its chemical and biological properties, and health benefit effects, remarking the aspects associated with the presence in tomarto and tomato comsuption.
Phytochemical
Health Benefits
Cite
Citations (7)
Watermelon contains lycopene, a red carotenoid pigment that has strong antioxidant properties. The lycopene content of watermelon is substantial, contributing 8−20 mg per 180 g serving. There are no reports on carotenoid changes in whole watermelon during storage. Three types of watermelon, open-pollinated seeded, hybrid seeded, and seedless types, were stored at 5, 13, and 21 °C for 14 days and flesh color, composition, and carotenoid content were compared to those of fruit not stored. Watermelons stored at 21 °C had increased pH, chroma, and carotenoid content compared to fresh fruit. Compared to fresh fruit, watermelons stored at 21 °C gained 11−40% in lycopene and 50−139% in β-carotene, whereas fruit held at 13 °C changed little in carotenoid content. These results indicate that carotenoid biosynthesis in watermelons can be affected by temperature and storage. Keywords: Lycopene; β-carotene; chilling injury; triploid watemelon; Citrullus lanatus (Thunb Matsum & Nakai)
Flesh
beta-Carotene
Carotene
Citrullus lanatus
Cite
Citations (61)
Fruits of the lutescent tomato genetic line were exposed to γ-radiation at different stages of maturity to determine the effect of ionizing radiation on carotenoid synthesis in the ripening fruit. Irradiation generally resulted in the inhibition of carotenogenesis. The effect was more pronounced at the higher dosage and in less mature fruit. Lycopene synthesis was inhibited more extensively than β-carotene synthesis. The total carotenoid content was also generally lower in irradiated fruits. It was proposed that the β-carotene in the tomato fruit is formed by a pathway not involving lycopene.
Carotene
beta-Carotene
Cite
Citations (6)