Secretome profile of Cellulomonas sp. B6 growing on lignocellulosic substrates

Abstract

Aims Lignocellulosic biomass deconstruction is a bottleneck for obtaining biofuels and value‐added products. Our main goal was to characterize the secretome of a novel isolate, Cellulomonas sp. B6, when grown on residual biomass for the formulation of cost‐efficient enzymatic cocktails. Methods and Results We identified 205 potential CAZymes in the genome of Cellulomonas sp. B6, 91 of which were glycoside hydrolases (GH). By secretome analysis of supernatants from cultures in either extruded wheat straw (EWS), grinded sugar cane straw (SCR) or carboxymethylcellulose (CMC), we identified which proteins played a role in lignocellulose deconstruction. Growth on CMC resulted in the secretion of two exoglucanases (GH6 and GH48) and two GH10 xylanases, while growth on SCR or EWS resulted in the identification of a diversity of CAZymes. From the 32 GHs predicted to be secreted, 22 were identified in supernatants from EWS and/or SCR cultures, including endo‐ and exoglucanases, xylanases, a xyloglucanase, an arabinofuranosidase/β‐xylosidase, a β‐glucosidase and an AA10. Surprisingly, among the xylanases, seven were GH10. Conclusions Growth of Cellulomonas sp. B6 on lignocellulosic biomass induced the secretion of a diverse repertoire of CAZymes. Significance and Impact of the Study Cellulomonas sp. B6 could serve as a source of lignocellulose‐degrading enzymes applicable to bioprocessing and biotechnological industries.

Optimisation of xylanases production by two Cellulomonas strains and their use for biomass deconstruction

“…The most abundant putative CAZymes in the WB secretome were a GH62 α-L-arabinofuranosidase (a debranching enzyme), two GH10 xylanases, a GH6 exoglucanase and a GH9 endoglucanse. As in previous studies, a high abundance of extracellular components of putative ABC transporters were also identified (Piccinni et al 2019). By culture in PWP, C. fimi secreted 4 GH10 (out of the 5 GH10 encoded in the genome) and 1 GH11 (the only one predicted).…”

“…Hydrolysis reactions were carried out at 40 °C, 400 rpm for 10 min. These conditions were established in a previous work (Piccinni et al 2019 ). Reducing sugars released from the reactions were measured by dinitrosalicylic acid (DNS) method (Miller 1959 ) using glucose or xylose standard curves.…”

“…Secretomic analysis was performed using flasks cultures of Cellulomonas sp. B6 in WB and C. fimi in PWP, in duplicate according to the protocol previously described by Piccinni et al ( 2019 ). Briefly, total proteins contained in cell-free supernatants were quantified by Bradford assay (Promega, Biodynamics, CABA, Argentina), precipitated with 10% w/w trichloroacetic acid and then resuspended in ultrapure water (resistivity of 18.2 MΩ × cm) to a final concentration of 1 mg/mL.…”

“…The (hemi)cellulolytic potential of strains belonging to the Cellulomonas genus, such as Cellulomonas fimi ATCC 484 (Wakarchuk et al 2016 ) and Cellulomonas sp. B6 (Piccinni et al 2019 ) has been demonstrated.…”

Digestive activity and organic compounds of Nezara viridula watery saliva induce defensive soybean seed responses

“…Samples were reduced with 20 mM DTT (Dithiothreitol) for 45 min at 56 °C, alkylated with 55 mM C 2 H 4 INO (iodoacetamide) for 45 min in the dark and digested with trypsin (Promega V5111) overnight at 37 °C. NanoLC was carried out as previously described 43 . For data acquisition XCalibur 3.0.63 (Thermo Scientific) software was used.…”