Cellulose biosynthesis using simple sugars available in residual cacao mucilage exudate

Worldwide only 8% of the biomass from harvested cacao fruits is used, as cacao beans, in chocolate-based products. Cacao mucilage exudate (CME), a nutrient-rich fluid, is usually lost during cacao beans fermentation. CME's composition and availability suggest a potential carbon source for cellulose production. CME and the Hestrin and Schramm medium were used, and compared, as growth media for bacterial cellulose (BC) production with Gluconacetobacter xylinus. CME can be used to produce BC. However, the high sugar content, low pH, and limited nitrogen sources in CME hinder G. xylinus growth affecting cellulose yields. BC production increased from 0.55 +/- 0.16 g L-1 up to 13.13 +/- 1.09 g L-1 after CME dilution and addition of a nitrogen source. BC production was scaled up from 30 mL to 15 L, using lab-scale experiments conditions, with no significant changes in yields and production rates, suggesting a robust process with industrial possibilities.

Automated summary

Cacao mucilage exudate (CME) can be used to produce bacterial cellulose (BC), but high sugar content, low pH, and limited nitrogen sources in CME can hinder G. xylinus growth affecting cellulose yields. By diluting CME and adding a nitrogen source, BC production significantly increased. Scaling up BC production from 30 mL to 15 L under lab-scale conditions showed no significant changes in yields and production rates, suggesting industrial possibilities are feasible.