Aqueous biphasic systems (ABSs) based on sodium polyacrylate (NaPA), ethylene oxide/propylene oxide (EO/PO) polymers, and (EO) x -(PO) y -(EO) x triblock copolymers were prepared and applied aiming at continuous fructooligosaccharide (FOS) production and separation. EO/PO hydrophilicity/hydrophobicity balance had a significant effect on ABS formation. To develop an integrated process including the continuous enzymatic (levansucrase) production of FOSs and their purification while improving the production yield by further glucose separation, the potential of these novel polymer-based ABSs as alternative platforms was investigated. They were used for the partitioning of different carbohydrates (FOS, sucrose, d-fructose, and d-glucose) and levansucrase. Results revealed a highly polymer-dependent partition of carbohydrates and a poorly dependent one of the enzymes. Changing EO/PO and copolymers, FOS was purified with high yields (72.94–100.0%). Using polypropylene glycol 400 + NaPA 8000-based ABS, the FOS was precipitated in the interphase and separated from the other components. Pluronic PE-6800 + NaPA 8000 was identified as the best ABS for FOS continuous production and in situ purification, while minimizing levansucrase inhibition by d-glucose. This system allowed selective partition of FOSs and d-glucose toward the top phase and that of levansucrase and its substrates toward the bottom one. COnductor-like Screening MOdel for Real Solvent (COSMO-RS) suggested that ABS formation may have been due to NaPA and polymer/copolymer competition to form hydrogen bonds with water molecules. Moreover, the partition of FOSs and sugar may have been the result of a subtle balance between hydrogen bonding of sugar and polymer/copolymer and electrostatic misfit of solute with NaPA. Finally, two integrated processes were proposed to be applied with real FOS extracts obtained by chemical or enzymatic hydrolysis of inulin or by transfructosylation of concentrated sucrose solutions using bacterial levansucrases.

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Background: Lignocellulosic biomass is an advantageous alternative to produce biofuels, despite its recalcitrant characteristic. There are microorganisms in nature capable of efficiently degrade biomass, such as the filamentous fungi. Among them, Aspergillus fumigatus var. niveus (AFUMN) has a wide variety of carbohydrate-active enzymes (CAZymes), especially hydrolases, but a low number of oxidative enzymes in its genome. To confirm the enzymatic profile of this fungus, this work analyzed the secretome of AFUMN cultured in sugarcane bagasse as sole carbon source. As expected, the secretome showed a predominance of hydrolytic enzymes compared to the oxidative activity. However, it is known that hydrolytic enzymes act in synergism with oxidative proteins to efficiently degrade cellulose polymer, such as the LPMOs (Lytic Polysaccharide Monooxygenases). Results: Thus, three LPMOs from the fungus Thermothelomyces thermophilus (TtLPMO9D, TtLPMO9H, and TtLPMO9O) were selected, heterologous expressed in Aspergillus nidulans, purified, and used to complement the AFUMN secretome aiming to evaluate the supplementation effect in the saccharification of sugarcane bagasse process. The saccharification assay was carried out using different concentrations of AFUMN secretome supplemented with recombinant T. thermophilus LPMOs, as well as ascorbic acid as reducing agent for oxidative enzymes. Conclusions: Through a statistic design created by Design-Expert software, we were capable to analyze a possible cooperative effect between these components. The results obtained indicated that, in general, the addition of TtLPMO9D and ascorbic acid did not favor the conversion process in this study, while TtLPMO9O had a highly significant cooperative effect in bagasse saccharification compared to the control using only AFUMN secretome.