Wheat Bran Hydrolysate Culture Medium Design for Talaromyces purpureogenus CFRM02 Pigment Production and Colour Characteristics

Abstract

Wheat bran hydrolysate (WBH) in combination with carbon and nitrogen was utilized as substrate for pigment production by Talaromyces purpureogenus CFRM02. Pigment yield was significantly increased (≈threefold: OD units and ≈twofold: redness [a* value]) by xylose supplementation with WBH compared to other carbon sources, whereas 1% xylose supplementation increased pigment production (1.57 ± 0.05 OD units and 49 ± 1.62 a* value). Pigment yield was low when WBH supplemented with 0.3% nitrogen sources. However, significant increase (≈2–2.5 fold, OD units and a* value) was observed, when yeast extract (1.2%), nitrate of sodium (1.2%) and potassium (1.6%) were supplemented. Accordingly, 16 WBH media were designed by supplementing carbon and nitrogen. Interestingly, the pigment production was significantly increased (1.59 OD units and 32 a* value) in the medium supplemented with 4% carbon and 0.9–1.2% nitrogen. T. purpureogenus CFRM02 was able to co-utilize xylose, fructose and glucose in WBH medium. The CIE Lab values indicated that pigment characteristics differed significantly among the media. Apparently, T. purpureogenus CFRM02 possesses alternative gene(s) or pathway(s) for xylose metabolism and channelled towards pigment biosynthesis. Comparative results revealed that 1% xylose supplementation to WBH makes the fermentation process economically competitive for pigment production.