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Bioprospecting for fungal enzymes for applications in microalgal-biomass based biorefineries

ABSTRACT: Microalgal biomass is a promising feedstock for biofuels, feed/food and biomaterials. However, while production and commercialization of single-product commodities is still not economically viable, obtaining multiple products in a biomass biorefinery faces several techno- economic challenges. The aim of this study was to identify a suitable source of hydrolytic enzymes for algal biomass saccharification. Screening of twenty-six fungal isolates for secreted enzymes activity on Chlamydomonas reinhardtii biomass resulted in the identification of Aspergillus niger IB-34 as a candidate strain. Solid state fermentation on wheat bran produced the most active enzyme preparations. From sixty-five proteins identified by LC-MS, the majority corresponded to predicted secreted proteins belonging to the Gene Ontology categories of catalytic activity/hydrolase activity on glycosyl and O-glycosyl compounds. Defatted biomass of the more biotechnologically relevant strains towards the production of commodities, Chlorella sorokiniana and Scenedesmus obliquus, was fully saccharified after a mild pretreatment at 80 °C for 10 min, at a high biomass load of 10 % (w/v). Deffated and 2 saccharified biomass of both strains was further converted into ethanol by fermentation with Saccharomyces cerevisiae at a theoretical maximum efficiency, either by separated or simultaneous sccharification and fermentation. The resulting insoluble protein after biomass defatting with an organic solvent and enzymatic saccharification resulted in a high digestibility in an in vitro digestion assay. Proof-of-concept is presented for an enzyme-assisted biomass biorefinery which recovered 81% of the main biomass fractions in a likely active form for the conversion of lipids and carbohydrates into biofuels and proteins into feed/food.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Aspergillus Niger Cbs 101883

SUBMITTER: Araceli Bader

LAB HEAD: Fabiana Consolo

PROVIDER: PXD034998 | Pride | 2023-03-10

REPOSITORIES: Pride

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Bioprospecting for fungal enzymes for applications in microalgal biomass biorefineries.

Bader Araceli Natalia AN Sanchez Rizza Lara L Consolo Verónica Fabiana VF Curatti Leonardo L

Applied microbiology and biotechnology 20221217 2-3

Microalgal biomass is a promising feedstock for biofuels, feed/food, and biomaterials. However, while production and commercialization of single-product commodities are still not economically viable, obtaining multiple products in a biomass biorefinery faces several techno-economic challenges. The aim of this study was to identify a suitable source of hydrolytic enzymes for algal biomass saccharification. Screening of twenty-six fungal isolates for secreted enzymes activity on Chlamydomonas rein ...[more]

PMID: 36527478

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