The aim of this study was the valorization of coffee industry residues, namely spent coffee grounds (SCG) as a source of oil, and silverskin (CS) as a source of both oil and biomass, under the concept of the circular economy. Therefore, crude oil from SCG was used to produce low-calorie structured lipids (SL) for food and pharmaceutical industries, and CS to produce biochar by pyrolysis for biotechnological uses. SL were obtained by acidolysis with caprylic or capric acid, or interesterification with ethyl caprylate or ethyl caprate, in solvent-free media, catalyzed by immobilized sn-1,3 regioselective lipases. Silverskin biochar (BIO) was directly used as enzyme carrier or to produce hybrid organic-silica (HB) supports for enzyme immobilization. Rhizopus oryzae lipase (ROL) immobilized on Amberlite (AMB), silica (SIL), BIO or HB, and the commercial immobilized Thermomyces lanuginosus (Lipozyme TL IM) and Rhizomucor miehei (Lipozyme RM IM) lipases were tested. Lipozyme RM IM showed better results in SL production than Lipozyme TLIM or ROL on BIO, SIL or HB. About 90% triacylglycerol conversion was attained after 7 h acidolysis or interesterification. Lipozyme RM IM was more stable in interesterification (80% and 65% activity with ethyl caprylate or ethyl caprate) than in acidolysis (first-order decay) after 10 reuses.

This work presents a framework for evaluating hybrid nanoflowers using Burkholderia cepacia lipase. It was expanded on previous findings by testing lipase hybrid nanoflowers (hNF-lipase) formation over a wide range of pH values (5–9) and buffer concentrations (10–100 mM). The free enzyme activity was compared with that of hNF-lipase. The analysis, performed by molecular docking, described the effect of lipase interaction with copper ions. The morphological characterization of hNF-lipase was performed using scanning electron microscopy. Fourier Transform Infrared Spectroscopy performed the physical–chemical characterization. The results show that all hNF-lipase activity presented values higher than that of the free enzyme. Activity is higher at pH 7.4 and has the highest buffer concentration of 100 mM. Molecular docking analysis has been used to understand the effect of enzyme protonation on hNF-lipase formation and identify the main the main binding sites of the enzyme with copper ions. The hNF-lipase nanostructures show the shape of flowers in their micrographs from pH 6 to 8. The spectra of the nanoflowers present peaks typical of the amide regions I and II, current in lipase, and areas with P–O vibrations, confirming the presence of the phosphate group. Therefore, hNF-lipase is an efficient biocatalyst with increased catalytic activity, good nanostructure formation, and improved stability.

The present research aims to study the process of immobilization of lipase from Burkholderia cepacia by physical adsorption on graphene oxide derived (GO) from grape seed biochar. Additionally, the modified Hummers method was used to obtain the graphene oxide. Moreover, Fourier transform infrared spectroscopy, Raman spectrum, X-ray diffraction, and point of zero charge were used for the characterization of the GO. The influences of pH, temperature, enzyme/support concentration on the catalytic activity were evaluated for the immobilized biocatalyst. The best immobilization was found (543 ± 5 U/g of support) in the pH 4.0. Considering the biochemical properties, the optimal pH and temperature were 3.0 and 50 °C, respectively, for the immobilized biocatalyst. Reusability studies exhibited that the immobilized lipase well kept 60% of its original activity after 5 cycles of reuse. Overall, these results showed the high potential of graphene oxide obtained from biochar in immobilization lipase, especially the application of nanobiocatalysts on an industrial scale.

The influence of the microenvironment within enzyme-support complexes on the activity of Burkholderia cepacia lipase (BCL) immobilized on silica (SiO₂-BCL) remains insufficiently understood. Without data on these interactions, it is challenging to determine whether modifications to the support material or immobilization protocols are needed for optimal enzyme activity and stability. Besides evaluating catalytic performance in esterification reactions, enzyme-support interactions were characterized using ²⁹Si NMR, FTIR, BET, DSC, TGA, SEM-EDS, and molecular docking simulations. In this study, NMR²⁹Si-based structural analysis revealed significant protein-surface (pore wall) interaction networks. The immobilization resulted in 88.6% efficiency and a protein loading of 17.72 mg·g^-1, enabling further structural and functional characterization. Molecular docking elucidated the interaction mechanisms between silica functional groups (Qⁿ sites) and BCL binding residues. Docking simulations indicated that the Q3 group interacts with the catalytic residue Ser87, potentially hindering substrate access to the active site. Spectroscopic and morphological analyses confirmed this interaction and correlated it with a significant decrease in enzymatic activity. Experimental evidence and FTIR analyses demonstrated that the increase in the α-helix content of SiO₂-BCL correlated with the observed decrease in catalytic productivity. BCL exhibited a significantly higher esterification productivity (150.82 μmol·h^-1·mg^-1) than SiO₂-BCL (28.10 μmol·h^-1·mg^-1), confirming the importance of optimal enzyme conformation for catalytic efficiency. The results highlight that, beyond the support's composition, the spatial orientation and specific interactions with functional groups are critical determinants of catalytic efficiency. This integrative approach may guide the rational design of enzyme-based biocatalysts using mesoporous materials.