Efficient and repeated production of succinic acid by turning sugarcane bagasse into sugar and support

Abstract

Here we reported an endeavor in making full use of sugarcane bagasse for biological production of succinic acid. Through NaOH pre-treatment and multi-enzyme hydrolysis, a reducing sugar solution mainly composed of glucose and xylose was obtained from the sugarcane bagasse. By optimizing portions of cellulase, xylanase, β-glucanase and pectinase in the multi-enzyme "cocktail", the hydrolysis percentage of the total cellulose in pre-treated sugarcane bagasse can be as high as 88.5%. A. succinogenes CCTCC M2012036 was used for converting reducing sugars into succinic acid in a 3-L bioreactor with a sugar-fed strategy to prevent cell growth limitation. Importantly, cells were found to be adaptive on the sugarcane bagasse residue, offering possibilities of repeated batch fermentation and replacement for MgCO3 with soluble NaHCO3 in pH modulation. Three cycles of fermentation without activity loss were realized with the average succinic acid yield and productivity to be 80.5% and 1.65g·L(-1)·h(-1).

Keywords: Fermentation; Hydrolysis; Succinic acid; Sugarcane bagasse.