Production of succinic acid from pineapple peel waste

Abstract

Background: Succinic acid is a crucial platform chemical for production of various industrially significant compounds. For a sustainable and eco-friendly process, succinic acid synthesis has been shifted towards the fermentative route using renewable biomass substrates. Pineapple consumption and processing generate an immense amount of waste from its non-edible peel portion. As a carbon source, pineapple peel can be valorized for succinic acid bioproduction. Results: The hydrothermal pretreatment (121°C, 15 min) of pineapple peel waste resulted in the highest sugar release of 35.22 g/L (18 g/L glucose and 17 g/L fructose). The subsequent fermentation of pineapple peel hydrolysate was performed by a natural succinic acid producer, Actinobacillus succinogenes TISTR 1994. When the non-detoxified hydrolysate was used as a sole carbon source, 6.21 g/L of succinic acid was produced from 26.16 g/L of sugars. Additional supplementation of 9 g/L mixed nitrogen source enhanced the formation of succinic acid to 9.96 g/L from roughly the same amount of sugar. The current production conditions using mainly hydrolysate-based medium gave the succinic acid yield of 0.39 g/g sugar suggesting feasibilities for further improvement. Conclusion: Bio-based succinic acid production was attempted for the first time using the solid pineapple waste as a main starting material. Results demonstrated a proof of concept that the abundant pineapple peel waste can serve as a renewable substrate for a low-cost, value-added bioconversion to succinic acid. Optimization of nutritional composition in hydrolysate is necessary to enhance the yield of succinic acid in future studies.