Production of violacein pigment using solid state fermentation

Abstract

Natural pigment from Chromobacterium violaceum, violacein is highly in demand due to its pharmacological properties. Submerged fermentation of Chromobacterium violaceum results in low yield of violacein due to extraction problems. Hence, solid state fermentation is proposed where separation of pigments is easier. Solid state fermentation of Chromobacterium violaceum UTM5 on sugarcane bagasse was tested in shake flask and a column system. Crude violacein was extracted using ethyl acetate and characterized using UV-Visible Spectrophotometer and Fourier Transform Spectroscopy (FTIR). Highest violacein production (5.11 mg/g SCB) was observed in sugarcane bagasse supplemented with 100 mg/L of L-tryptophan at 30 °C for three days. The violacein observed at 556 nm using UV-Vis spectra and within the range of λ_max as reported by other researchers. FTIR spectrum of violacein showed a weak band of OH stretching at 3215.98 cm^-1 which might overlap with the N-H band. Two stretching bands at 1603.98 cm^-1 and 1702.85 cm^-1 were assigned to the C=O amide groups. Intermediate C-N band was observed at 1203.62 cm^-1. This study showed that the violacein produced in solid state fermentation was quite similar as that produced using submerged fermentation.