A closed-loop circularity in wood sugar as a renewable carbon source for fungal pigment production and application of pigments in wood colouration

Abstract

The main objective is to demonstrate closed-loop circularity in the production of fungal pigment from renewable wood sugar hydrolysate (WSH) and impregnation of colour pigment into wood. Talaromyces sp 43 M, isolated from a New Zealand vineyard, was identified as Talaromyces ruber (TR) using multi-gene phylogenetic analysis. A mild pretreatment followed by ball milling was used to prepare Pinus radiata pulp which was enzymatically hydrolysed to generate WSH. Malt 30 g/L or WSH 40 g/L were optimum carbon sources when supplemented with peptone 10 g/L and meat extract 1 g/L as optimum nitrogen sources giving maximum production of extracellular pigment. TR completely metabolizes multiple carbon sources as well as fermentation inhibitors to elicit pigment production. The CIELAB colour characteristics of the pigment vary as a response to carbon sources (malt vs WSH) and fermentation time. The fluorescent pigment produced in malt and WSH medium were efficiently impregnated into wooden blocks.