Dyeing of silk fabric with phenazine from Pseudomonas species

Phenazines, namely oxychlororaphin and pyorubin, were extracted from Pseudomonas sp., purified and their dyeing potential as colorants for silk dyeing were examined. The effects of the process variables, such as phenazine concentration, pH, temperature, time, type of mordant, relative colour strength and fastness properties have been studied. The results showed that the optimum condition for dyeing was 90 degrees C at pH 3 and dyeing time 90 min for oxychlororaphin, and 70 degrees C at pH 3 and dyeing time 60 min for pyorubin. The K/S value of a pre-mordanted silk fabric with oxychlororaphin was high when compared to that with the pyorubin. The antimicrobial activity of a dyed silk fabric was tested against Salomonella paratyphi, Escherichia coli and Shigella flexneri.