Short-chain carboxylates such as acetate are easily produced through mixed culture fermentation of many biological waste streams, although routinely digested to biogas and combusted rather than harvested. We developed a pipeline to extract and upgrade short-chain carboxylates to esters via membrane electrolysis and biphasic esterification. Carboxylate-rich broths are electrolyzed in a cathodic chamber from which anions flux across an anion exchange membrane into an anodic chamber, resulting in a clean acid concentrate with neither solids nor biomass. Next, the aqueous carboxylic acid concentrate reacts with added alcohol in a water-excluding phase to generate volatile esters. In a batch extraction, 96 ± 1.6% of the total acetate was extracted in 48 h from biorefinery thin stillage (5 g L(-1) acetate) at 379 g m(-2) d(-1) (36% Coulombic efficiency). With continuously regenerated thin stillage, the anolyte was concentrated to 14 g/L acetic acid, and converted at 2.64 g (acetate) L(-1) h(-1) in the first hour to ethyl acetate by the addition of excess ethanol and heating to 70 °C, with a final total conversion of 58 ± 3%. This processing pipeline enables direct production of fine chemicals following undefined mixed culture fermentation, embedding carbon in industrial chemicals rather than returning them to the atmosphere as carbon dioxide.
Enzymatic degumming trials were performed on crude extracted soybean (SBO) and rapeseed oils (RSO) with a microbial phospholipase A1 (Lecitase Ultra®). We obtained a degummed oil with a phosphorus content < 10 mg/kg when applying an enzyme dosage of 30 mg/kg and (feedstock dependent) a contact time of 10–120 min. While a good degumming efficiency can already be obtained after a relative short reaction time, it was observed that a longer reaction time (1–2 h) is required for complete degradation of the phospholipids (PL), which results in a yield increase. We demonstrated that Lecitase Ultra® has no specificity for a given PL, but that the rate of conversion depends on the PL composition of the crude oil. After 60 min, 80% of phosphatidyl ethanolamine (PE) was degraded to its lyso‐form while only 40% of phosphatidyl inositol (PI) was converted in the same time interval. The formation of glycerophospholipids (GPL) was only observed after 60 min reaction.
Practical applications: Practical advantages and disadvantages of the use of Lecithase Ultra for enzymatic degumming of oils is described, focusing on soybean oil and rapeseed oil. The information will be valuable and important for the oil refining industry.
Degumming of soybean and rapeseed oils with phospholipase A1 (Lecithase Ultra) was performed and it was demonstrated that there is no specificity for a given phospholipid. However, the conversion rate depends on the phospholipid composition of the crude oils.
BACKGROUND: There is an increased need to replace materials derived from fossil sources by renewables. Sugar-cane derived carbohydrates are very abundant in Brazil and are the cheapest sugars available in the market, with more than 400 million tons of sugarcane processed in the year 2007. The objective of this work was to study the preparation of sugar acrylates from free sugars and free acrylic acid, thus avoiding the previous preparation of protected sugar derivatives, such as glycosides, or activated acrylates, such as vinyl acrylate. RESULTS: Lipase catalyzed esterification of three mono-and two disaccharides with acrylic acid, in the presence or absence of molecular sieves was investigated. The reactions were monitored by high-performance liquid chromatography (HPLC) and the products were analyzed by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. The main products are mono-and diacrylates, while higher esters are formed as minor products. The highest conversion to sugar acrylates was observed for the D-glucose and D-fructose, followed by D-xylose and D-maltose. Molecular sieves had no pronounced effect on the conversion CONCLUSIONS: A feasible method is described to produce and to characterize sugar acrylates, including those containing more than two acrylate groups. The process for production of these higher esters could potentially be optimized further to produce molecules for cross-linking in acrylate polymerization and other applications. The direct enzymatic esterification of free carbohydrates with acrylic acid is unprecedented.
The spread of the new human coronavirus, SARS-CoV-2, has become a global health issue, causing millions of deaths due to complications associated with infections in the respiratory tract. 1 Person-to-person aerial transmission mechanism 2 places the use of masks among the three most important recommendations to contain the spread of COVID-19, a disease caused by SARS-CoV-2, along with social distancing and sanitation of hands and objects. A recent study suggests that masks could reduce disease severity since they can reduce viral load. 3 Surgery and homemade masks are employed worldwide due to their higher availability and lower price. However, they are prone to rapid contamination due to breathing, manipulation, and interpersonal contact. Virucidal coatings could be applied to the mask surface, enhancing both protection and durability.Several studies have shown the antimicrobial activity of metallic elements, including those from the copper group. 4 Tremiliosi and coworkers reported silver-nanoparticle-based coatings' capability to inhibit the replication of SARS-CoV-2
Antiviral and non-toxic effects of silver nanoparticles onto in vitro cells infected with coronavirus were evaluated in this study using High-Resolution Magic-Angle Spinning Nuclear Magnetic Resonance (HR-MAS NMR) spectroscopy. Silver nanoparticles were designed and synthesized using an orange flavonoid—hesperetin (HST)—for reduction of silver(I) and stabilization of as obtained nanoparticles. The bio-inspired process is a simple, clean, and sustainable way to synthesize biogenic silver nanoparticles (AgNP@HST) with diameters of ∼20 nm and low zeta potential (−40 mV), with great colloidal stability monitored for 2 years. The nanoparticles were used for the fabrication of two types of antiviral materials: colloids (AgNP@HST spray) and 3D flexible nanostructured composites. The composites, decorated with AgNP@HST (0.05 mmol L−1), were made using cellulose nanofibers (CNF) obtained from orange peel and graphene oxide (GO), being denominated CNF@GO@AgNP@HST. Both materials showed high virucidal activity against coronaviruses in cell infection in vitro models and successfully inhibited the viral activity in cells. HR-MAS 1H-NMR technique was used for determining nanomaterials’ effects on living cells and their influences on metabolic pathways, as well as to study viral effects on cells. It was proven that none of the manufactured materials showed toxicity towards the intact cells used. Furthermore, viral infection was reverted when cells, infected with the coronavirus, were treated using the as-fabricated nanomaterials. These significant results open possibilities for antiviral application of 3D flexible nanostructured composite such as packaging papers and filters for facial masks, while the colloidal AgNP@HST spray can be used for disinfecting surfaces, as well as a nasal, mouth, and eye spray.
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