Preparation and characterization of new silica-based heterofunctional biocatalysts utilizing low-cost lipase Eversa^® Transform 2.0 and evaluation of their catalytic performance in isoamyl esters production from <i>Moringa oleifera</i> Lam oil

Due to the need to replace lubricants derived from polluting processes and inputs, bioprocesses and raw materials such as vegetable oils have been used for the production of biolubricants. In this study, the synthesis of esters with lubricating potential was conducted through enzymatic hydroesterification. For complete hydrolysis of Moringa oleifera Lam. seed oil (MOSO), Candida rugosa lipase was applied under conditions already established in the literature. Subsequently, the synthesis of esters of industrial interest was carried out through esterification using a lipase (Eversa Transform 2.0 (ET2.0)) immobilized by different functional groups on heterofunctional silica-based supports: epoxy-silica (Epx), glyoxyl-silica (Gly), and amino-glutaraldehyde-silica (AmG). Two drying pre-treatment techniques were used to improve the immobilization yield of the ET2.0 lipase on different pre-treated supports: evaporation in a drying oven (with improvements ranging from 15% to 46%) and pressure difference in a desiccator (with improvements ranging from 24% to 43%). The immobilizing supports and biocatalysts were characterized to verify their morphologies, structures, and topographies. Deconvolution was performed to evaluate the secondary structure of the ET2.0 lipase and showed increases in the α-helix and β-sheet regions for all biocatalysts after the immobilization process. In a solvent-free medium, the AmG-70h support performed best in the esterification reaction, at around 90% conversion, with a load of 1.65 mg of protein in the reaction. Moreover, it obtained a productivity around 4.45 times that of free ET2.0 lipase, maintaining its original activity until the fourth cycle. This work offers the opportunity to understand and synthesize new biocatalysts with a low-cost genetically modified lipase using a renewable raw material, opening new possibilities to fill gaps that still exist in the use of lipases for biolubricant production

CUBES: a UV spectrograph for the future

In spite of the advent of extremely large telescopes in the UV/optical/NIR range, the current generation of 8-10m facilities is likely to remain competitive at ground-UV wavelengths for the foreseeable future. The Cassegrain U-Band Efficient Spectrograph (CUBES) has been designed to provide high-efficiency (>40%) observations in the near UV (305-400 nm requirement, 300-420 nm goal) at a spectral resolving power of R>20,000, although a lower-resolution, sky-limited mode of R ~ 7,000 is also planned. CUBES will offer new possibilities in many fields of astrophysics, providing access to key lines of stellar spectra: a tremendous diversity of iron-peak and heavy elements, lighter elements (in particular Beryllium) and light-element molecules (CO, CN, OH), as well as Balmer lines and the Balmer jump (particularly important for young stellar objects). The UV range is also critical in extragalactic studies: the circumgalactic medium of distant galaxies, the contribution of different types of sources to the cosmic UV background, the measurement of H2 and primordial Deuterium in a regime of relatively transparent intergalactic medium, and follow-up of explosive transients. The CUBES project completed a Phase A conceptual design in June 2021 and has now entered the Phase B dedicated to detailed design and construction. First science operations are planned for 2028. In this paper, we briefly describe the CUBES project development and goals, the main science cases, the instrument design and the project organization and management

CUBES: the Cassegrain U-band Efficient Spectrograph

In the era of Extremely Large Telescopes, the current generation of 8-10m facilities are likely to remain competitive at ground-UV wavelengths for the foreseeable future. The Cassegrain U-Band Efficient Spectrograph (CUBES) has been designed to provide high-efficiency (> 40%) observations in the near UV (305-400 nm requirement, 300-420 nm goal) at a spectral resolving power of R >20, 000 (with a lower-resolution, sky-limited mode of R ~7, 000). With the design focusing on maximizing the instrument throughput (ensuring a Signal to Noise Ratio (SNR) ~20 per high-resolution element at 313 nm for U ~18.5 mag objects in 1h of observations), it will offer new possibilities in many fields of astrophysics, providing access to key lines of stellar spectra: a tremendous diversity of iron-peak and heavy elements, lighter elements (in particular Beryllium) and light-element molecules (CO, CN, OH), as well as Balmer lines and the Balmer jump (particularly important for young stellar objects). The UV range is also critical in extragalactic studies: the circumgalactic medium of distant galaxies, the contribution of different types of sources to the cosmic UV background, the measurement of H2 and primordial Deuterium in a regime of relatively transparent intergalactic medium, and follow-up of explosive transients. The CUBES project completed a Phase A conceptual design in June 2021 and has now entered the detailed design and construction phase. First science operations are planned for 2028

Tuning of Lecitase features via solid-phase chemical modification: Effect of the immobilization protocol

Lecitase Ultra (a quimeric fosfolipase commercialized by Novozymes) has been immobilized via two different strategies: mild covalent attachment on cyanogen bromide agarose beads and interfacial activation on octyl-agarose beads. Both immobilized preparations have been submitted to different individual or cascade chemical modifications (amination, glutaraldehyde or 2,4,6-trinitrobenzensulfonic acid (TNBS) modification) in order to check the effect of these modifications on the catalytic features of the immobilized enzymes (including stability and substrate specificity under different conditions). The first point to be remarked is that the immobilization strongly affects the enzyme catalytic features: octyl-Lecitase was more active versus p-nitrophenylbutyrate but less active versus methyl phenylacetate than the covalent preparations. Moreover, the effects of the chemical modifications strongly depend on the immobilization strategy used. For example, using one immobilization protocol a modification improves activity, while for the other immobiled enzyme is even negative. Most of the modifications presented a positive effect on some enzyme properties under certain conditions, although in certain cases that modification presented a negative effect under other conditions. For example, glutaraldehyde modification of immobilized or modified and aminated enzyme permitted to improve enzyme stability of both immobilized enzymes at pH 7 and 9 (around a 10-fold), but only the aminated enzyme improved the enzyme stability at pH 5 by glutaraldehyde treatment. This occurred even though some intermolecular crosslinking could be detected via SDS-PAGE. Amination improved the stability of octyl-Lecitase, while it reduced the stability of the covalent preparation. Modification with TNBS only improved enzyme stability of the covalent preparation at pH 9 (by a 10-fold factor).We gratefully recognize the support from the Spanish Government, grant CTQ2009-07568, grant VIE cod 5706 (UIS-Colombia) and CNPq (Brazil). The predoctoral fellowships for Ms. García-Galán (Spanish Government) and Mr dos Santos (CNPq, Brazil) are also recognized. Dr Pereira thanks Fundación Carolina and UNIFAL-MG.Peer Reviewe