Editor: Wolfgang Kneifel
Antimicrobial activities of amino acid derivatives of monascus pigments
Article first published online: 12 SEP 2006
FEMS Microbiology Letters
Volume 264, Issue 1, pages 117–124, November 2006
How to Cite
Kim, C., Jung, H., Kim, Y. O. and Shin, C. S. (2006), Antimicrobial activities of amino acid derivatives of monascus pigments. FEMS Microbiology Letters, 264: 117–124. doi: 10.1111/j.1574-6968.2006.00451.x
- Issue published online: 13 SEP 2006
- Article first published online: 12 SEP 2006
- Received 15 November 2005; revised 19 June 2006; accepted 8 August 2006.First published online 12 September 2006.
- Monascus pigment;
- amino acid derivatives;
- antimicrobial activity
Amino acid derivatives of monascus pigments were produced by fermentation, and their antimicrobial activities were determined. Thirty-nine l- and d-forms of amino acids were added as a precursor to the fermentation medium for derivation of pigments. Derivatives with l-Phe, d-Phe, l-Tyr, and d-Tyr exhibited high activities against Gram+ and Gram− bacteria with MIC values of c. 4–8 μg mL−1. The control red pigment exhibited minimal inhibitory concentration (MIC) values higher than 32 μg mL−1. Derivatives with l-Asp, d-Asp, l-Tyr, and d-Tyr were effective against the filamentous fungi Aspergillus niger, Penicillium citrinum, and Candida albicans. Monascus derivatives of amino acids having a phenyl ring like Phe and Tyr derivatives showed high antimicrobial activities. Incubation of the l-Phe derivative with Bacillus subtilis caused cells to aggregate with formation of pellets. Easy adsorption of the l-Phe pigment derivative to the surface of Escherichia coli cells was observed via SEM and TEM. Addition of monascus pigment derivatives decreased the oxygen uptake rate of E. coli in culture. The antimicrobial activities of pigment derivatives are considered to be related to the reduced availability of oxygen for the cells adsorbed with pigment.