Extract from a mutant Rhodobacter sphaeroides as an enriched carotenoid source

  • ChihChiang Wang
  • Shangwu Ding
  • Kuo-Hsun Chiu
  • Wen-Sheng Liu
  • Tai-Jung Lin
  • Zhi-Hong Wen


Background: The extract Lycogen™ from the phototrophic bacterium Rhodobacter sphaeroides (WL-APD911) has attracted significant attention because of its promising potential as a bioactive mixture, attributed in part to its anti-inflammatory properties and anti-oxidative activity.

Objective: This study aims to investigate the components of Lycogen™ and its anti-inflammatory properties and anti-oxidative activity.

Design and results: The mutant strain R. sphaeroides (WL-APD911) whose carotenoid 1,2-hydratase gene has been altered by chemical mutagenesis was used for the production of a new carotenoid. The strain was grown at 30°C on Luria–Bertani (LB) agar plates. After a 4-day culture period, the mutant strain displayed a 3.5-fold increase in carotenoid content, relative to the wild type. In the DPPH test, Lycogen™ showed more potent anti-oxidative activity than lycopene from the wild-type strain. Primary skin irritation test with hamsters showed no irritation response in hamster skins after 30 days of treatment with 0.2% Lycogen™. Chemical investigations of Lycogen™ using nuclear magnetic resonance (NMR) 1H, 13C, and COSY/DQCOSY spectra have identified spheroidenone and methoxyneurosporene. Quantitative analysis of these identified compounds based on spectral intensities indicates that spheroidenone and methoxyneurosporene are major components (approximately 1:1); very small quantities of other derivatives are also present in the sample.

Conclusions: In this study, we identified the major carotenoid compounds contained in Lycogen™, including spheroidenone and methoxyneurosporene by high-resolution NMR spectroscopy analysis. The carotenoid content of this mutant strain of R. sphaeroides was 3.5-fold higher than that in normal strain. Furthermore, Lycogen™ from the mutant strain is more potent than lycopene from the wild-type strain and does not cause irritation in hamster skins. These findings suggest that this mutant strain has the potential to be used as an enriched carotenoid source.

Keywords: anti-oxidative; Rhodobacter sphaeroides; LycogenTM; phototrophic bacteria; carotenoid; methoxyneurosporene

(Published: 31 March 2016)

Citation: Food & Nutrition Research 2016, 60: 29580 - http://dx.doi.org/10.3402/fnr.v60.29580


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How to Cite
Wang C., Ding S., Chiu K.-H., Liu W.-S., Lin T.-J., & Wen Z.-H. (2016). Extract from a mutant <em>Rhodobacter sphaeroides</em&gt; as an enriched carotenoid source. Food & Nutrition Research, 60. https://doi.org/10.3402/fnr.v60.29580
Original Articles