Biosynthesis of a novel C30 carotenoid in Bacillus firmus isolates
Article first published online: 2 AUG 2012
© 2012 The Authors Journal of Applied Microbiology © 2012 The Society for Applied Microbiology
Journal of Applied Microbiology
Volume 113, Issue 4, pages 888–895, October 2012
How to Cite
Steiger, S., Perez-Fons, L., Fraser, P.D. and Sandmann, G. (2012), Biosynthesis of a novel C30 carotenoid in Bacillus firmus isolates. Journal of Applied Microbiology, 113: 888–895. doi: 10.1111/j.1365-2672.2012.05377.x
- Issue published online: 12 SEP 2012
- Article first published online: 2 AUG 2012
- Accepted manuscript online: 28 JUN 2012 03:47AM EST
- Manuscript Accepted: 16 JUN 2012
- Manuscript Revised: 13 JUN 2012
- Manuscript Received: 22 MAY 2012
- EU. Grant Number: 207948
- 4,4′ diapolycopene-dioate ester;
- antioxidative properties;
- C30 carotenoid biosynthesis pathway;
- red-pigmented Bacillus firmus isolates
Pigmented Bacillus spp. with probiotic properties have been isolated. In the yellow-/orange-coloured strains, the carotenoid pigments present have been characterized. In contrast, the carotenoids present in the Bacillus isolates coloured red await identification. The present article reports progress on the elucidation of the pigment biosynthetic pathway in these red-pigmented Bacillus firmus strains.
Methods and Results
A combination of UV/Vis, chromatographic and mass spectrometry (MS) has revealed the properties of the predominant pigment and the end-point carotenoid of the pathway to be methyl 4,4′-diapolycopene-dioate after transmethylation. The diglycosyl ester of 4,4′-diapolycopene-dioate persists in vivo prior to chemical treatment. Different mutants and inhibitor treatment were employed to establish the C30 biosynthesis pathway with all precursors and intermediates to 4,4′-diapolycopene-dioate detected, which include 4,4′-diapophytene and all desaturation intermediates to 4,4′-diapolycopene and 4,4′-diapolycopene-dialdehyde. To cultures synthesizing the 4,4′-diapolycopene-dioate derivative and those in which its formation was inhibited, oxidative stress was induced by peroxide treatment. Conditions that decreased the growth rate of the pigmented cells by only 30% caused a complete growth inhibition of the culture devoid of the 4,4′-diapolycopene-dioate derivative.
This finding demonstrates the diversity of C30 carotenoid biosynthesis in Bacillus species and the antioxidative function of the 4,4′-diapolycopene-dioate derivative in B. firmus cells.
Significance and Impact of the Study
It could be shown that the C30 4,4′-diapolycopene-dioate derivatives protect pigmented B. firmus from peroxidative reactions. Under oxidative conditions, this can be an ecological advantage over nonpigmented (=noncarotenogenic) strains that are equally abundant.