Extract from a mutant Rhodobacter sphaeroides as an enriched carotenoid source

Chih-Chiang Wang; Shangwu Ding; Kuo-Hsun Chiu; Wen-Sheng Liu; Tai-Jung Lin; Zhi-Hong Wen

doi:10.3402/fnr.v60.29580

Extract from a mutant Rhodobacter sphaeroides as an enriched carotenoid source

Food Nutr Res. 2016 Mar 31:60:29580. doi: 10.3402/fnr.v60.29580. eCollection 2016.

Authors

Chih-Chiang Wang^{1

2}, Shangwu Ding³, Kuo-Hsun Chiu⁴, Wen-Sheng Liu^{1

4

5}, Tai-Jung Lin⁶, Zhi-Hong Wen⁷

Affiliations

¹ Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan.
² Department of Medicine, Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan.
³ Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan.
⁴ Department and Graduate Institute of Aquaculture, National Kaohsiung Marine University, Kaohsiung, Taiwan.
⁵ Asia-Pacific Biotech Developing, Inc., Kaohsiung, Taiwan.
⁶ Department of Pharmacy and Graduate Institute of Pharmaceutical Technology, Tajen University, Pingtun County, Taiwan.
⁷ Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan; wzh@mail.nsysu.edu.tw.

Abstract

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) (1)H, (13)C, 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: Lycogen™; Rhodobacter sphaeroides; anti-oxidative; carotenoid; methoxyneurosporene; phototrophic bacteria.