Characterization of a novel strain of Aspergillus aculeatinus: From rhamnogalacturonan type I pectin degradation to improvement of fruit juice filtration

Catalina Duran Garzon , Olivier Habrylo (1) , Adrien Lemaire (2, 3, 4) , Anais Guillaume , Yoann Carre (5) , Clemence Millet , Catherine Fourtot-Brun , Pauline Trezel (2) , Pascal Le Blond , Aurore Perrin , Stephane George (6) , Magali Wagner (6) , Yves Coutel , Loic Levavasseur (1) , Corinne Pau-Roblot (3, 4) , Jerome Pelloux (3, 4)

1 Groupe Soufflet
2 BioEcoAgro - UMR transfrontalière INRAE 1158
3 BioEcoAgro BIOPI-UPJV
4 BioEcoAgro - Equipe 1 - Functioning and adaptation of the plant in interaction with its environment
5 UGSF - Unité de Glycobiologie Structurale et Fonctionnelle - UMR 8576
6 Centre Technique de la Conservation des Produits Agricoles

Aspergillus spp. are well-known producers of pectinases commonly used in the industry. Aspergillus aculeatinus is a recently identified species but poorly characterized. This study aimed at giving a comprehensive characterization of the enzymatic potential of the O822 strain to produce Rhamnogalacturonan type I (RGI)-degrading enzymes. Proteomic analysis identified cell wall degrading enzymes (cellulases, hemicellulases, and pectinases) that accounted for 92 % of total secreted proteins. Twelve out of fifty proteins were identified as RGI-degrading enzymes. NMR and enzymatic assays revealed high levels of arabinofuranosidase, arabinanase, galactanase, rhamnogalacturonan hydrolases and rhamnogalacturonan acetylesterase activities in aqueous extracts. Viscosity assays carried out with RGI-rich camelina mucilage confirmed the efficiency of enzymes secreted by O822 to hydrolyze RGI, by decreasing viscosity by 70 %. Apple juice trials carried out at laboratory and pilot scale showed an increase in filtration flow rate and yield, paving the way for an industrial use of enzymes derived from A. aculeatinus.

Mots clés: Solid-state fermentation; Juice filtration; Aspergillus aculeatinus; RGI-type pectins-degrading enzymes; Proteome

Domaines: Sciences du Vivant [q-bio]

Catalina Duran Garzon, Olivier Habrylo, Adrien Lemaire, Anais Guillaume, Yoann Carre, et al.. Characterization of a novel strain of Aspergillus aculeatinus: From rhamnogalacturonan type I pectin degradation to improvement of fruit juice filtration. Carbohydrate Polymers, 2021, 262, pp.117943. ⟨10.1016/j.carbpol.2021.117943⟩. ⟨hal-03610098⟩