Precursor-feeding and altered-growth conditions reveal novel blue pigment production by Rubrivivax benzoatilyticus JA2.

OBJECTIVE: To explore the secondary metabolite biosynthetic potential of Rubrivivax benzoatilyticus JA2 using a new metabolite mining strategy.

RESULTS: Combination of precursor-feeding and altered growth conditions were used to mine new biomolecules. Strain JA2 utilised L-phenylalanine as sole source of nitrogen and showed pigments production only under phenylalanine-amended aerobic cultures. Stable isotope based precursor feeding studies indicated the blue pigment consists of 4-phenyl rings derived from L-phenylalanine. The purified blue pigment displayed characteristic visible-absorption and pH-dependent color variations. Precursor-feeding under altered growth conditions activated the plausible novel aromatic pigment production in strain JA2.

CONCLUSION: Our approach unraveled the previously unknown pigment synthesis in strain JA2 and demonstrated the potential of mining strategy in discovering the hidden secondary metabolite repertoire in microorganisms.