Secretomic analysis of cheap enzymatic cocktails of Aspergillus niger LBM 134 grown on cassava bagasse and sugarcane bagasse

ABSTRACT

Currently, agroindustrial wastes are little used for generating value-added products; hence, their use of these waste to produce enzymatic cocktails for the conversion of lignocellulosic biomass to fermentable sugars is a very interesting alternative in the second-generation bioethanol process. The Ascomycota fungus Aspergillus niger LBM 134 produces hydrolytic enzymes in large proportions. In this work, A. niger LBM 134 was grown on sugarcane and cassava bagasses under optimized conditions. To identify the extracellular enzymes involved in the degradation of these agroindustrial wastes, the secretomes of the culture supernatants of the fungus were analyzed and validated by biochemical assays of the enzymatic activities. A. niger LBM 134 secreted higher quantities of xylanases and accessory hemicellulases when it grew on sugarcane bagasse, whereas more cellulases, amylases, and pectinases were secreted when it grew on cassava bagasse. These findings suggest two promising enzyme cocktails for the hydrolysis of lignocellulose carbohydrate polymers to fermentable sugars. These bioinformatic analysis were functional validates through enzymatic biochemical assays that confirm the biotechnological potential of A. niger LBM 134 for the bioconversion of hemicellulosic substrates such as sugarcane and cassava bagasses.

GRAPHICAL ABSTRACT

KEYWORDS:

• Aspergillus niger
• cassava bagasse
• functional validation
• glycoside hydrolases
• secretomic analysis
• sugarcane bagasse

Supplemental Material

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ACKNOWLEDGMENTS

We would like to acknowledge to Chemical and Biological Studies by Mass Spectrometry Center (CEQUIBIEM) for proteomic analysis carried out under the direction of Silva Moreno, PhD. We also thank Silvana Maidana, PhD (Department of Science and Food Technology, Faculty of Exact, Chemical and Natural Sciences, National University of Misiones), for biochemical determination of pectinases.