Efficient biorefinery of whole cassava for citrate production using Aspergillus niger mutated by atmospheric and room temperature plasma and enhanced co-saccharification strategy.

Abstract

The non-grain crop cassava has attracted intense attention in the biorefinery process. However, efficient biorefinery of whole cassava is faced with some challenges due to the existence of strain inhibition and refractory cellulose during the citrate production process. Here, a novel breeding method - atmospheric and room temperature plasma (ARTP) - was applied for strain improvement of citrate-producing strain Aspergillus niger from whole cassava. The citrate yield of the mutant obtained using ARTP mutagenesis increased by 36.5% in comparison with the original strain. Moreover, citric acid fermentation was further improved on the basis of an enhanced co-saccharification strategy by supplementing glucoamylase and cellulase. The fermentation efficiency increased by 35.8% with a 17.0g L-1 reduction in residual sugar on a pilot scale. All these results confirmed that a combination of the novel breeding method and enhanced co-saccharification strategy could be used to efficiently refine whole cassava. The results also provide inspiration for the production of value-added products and waste disposal in agro-based industries. © 2021 Society of Chemical Industry.