Search

Brazil has the second-highest COVID-19 death rate worldwide, and Rio de Janeiro is among the states with the highest rate in the country. Although vaccine coverage has been achieved, it is anticipated that COVID-19 will transition into an endemic disease. It is concerning that the molecular mechanisms underlying clinical evolution from mild to severe disease, as well as the mechanisms leading to long COVID-19, are not yet fully understood. NMR and MS-based metabolomics were used to identify metabolites associated with COVID-19 pathophysiology and disease outcome. Severe COVID-19 cases (n = 35) were enrolled in two reference centers in Rio de Janeiro within 72 h of ICU admission, alongside 12 non-infected control subjects. COVID-19 patients were grouped into survivors (n = 18) and non-survivors (n = 17). Choline-related metabolites, serine, glycine, and betaine, were reduced in severe COVID-19, indicating dysregulation in methyl donors. Non-survivors had higher levels of creatine/creatinine, 4-hydroxyproline, gluconic acid, and N-acetylserine, indicating liver and kidney dysfunction. Several changes were greater in women; thus, patients’ sex should be considered in pandemic surveillance to achieve better disease stratification and improve outcomes. These metabolic alterations may be useful to monitor organ (dys) function and to understand the pathophysiology of acute and possibly post-acute COVID-19 syndromes.

Candida rugosa lipase (CRL) was immobilized by the ionic gelling technique using alginate and chitosan as encapsulating agents. An immobilization yield of 99% and an immobilization efficiency of 51% were obtained. Maximum hydrolytic activity for free and immobilized CRL was detected at 40 °C and for synthesis activity at 35 °C. The optimum pH for immobilized and free CRL hydrolysis activity was 8.0. The Vmax obtained for the hydrolysis reaction was higher for free CRL (4121.4 μmol/min/g) compared to immobilized CRL (2359.13 μmol/min/g). A Vmax of 2.24 μmol/min/g was detected for the synthetic activity of free CRL. The Km obtained for the hydrolysis reaction was higher (660.02 μmol/L) for immobilized CRL than for free CRL (403.06 μmol/L). For the synthetic activity, a Km of 234.44 μmol/L was calculated. The conversion of β-sitosterol oleate ranged from 80.85 to 96.84% for free CRL, higher than the maximum found for immobilized CRL (32%). The scale-up (scale factor: 50) with the free CRL was successfully performed, achieving a high conversion value (92%) in a 500 mL bioreactor. This conversion value was within the range predicted by the mathematical model obtained using mini reactors. These mini reactors are good models to test several conditions of enzyme reactions that are intended for large scales.

Lipases are versatile enzymes widely used in the pharmaceutical, cosmetic, and food industries. They are green biocatalysts with a high potential for industrial use compared to traditional chemical methods. In recent years, lipases have been used to synthesize a wide variety of molecules of industrial interest, and extraordinary results have been reported. In this sense, this review describes the important role of lipases in the synthesis of phytosterol esters, which have attracted the scientific community’s attention due to their beneficial effects on health. A systematic search for articles and patents published in the last 20 years with the terms “phytosterol AND esters AND lipase” was carried out using the Scopus, Web of Science, Scielo, and Google Scholar databases, and the results showed that Candida rugosa lipases are the most relevant biocatalysts for the production of phytosterol esters, being used in more than 50% of the studies. The optimal temperature and time for the enzymatic synthesis of phytosterol esters mainly ranged from 30 to 101 °C and from 1 to 72 h. The esterification yield was greater than 90% for most analyzed studies. Therefore, this manuscript presents the new technological approaches and the gaps that need to be filled by future studies so that the enzymatic synthesis of phytosterol esters is widely developed.