48 research outputs found
Development and economic evaluation of an eco-friendly biocatalytic synthesis of emollient esters.
©. This manuscript version is made available under the CC-BY-NC-ND license http://creativecommons.org/licenses/ccby-nc-nd/4.0/
This document is the Accepted version of a Published Work that appeared in final form in [Bioprocess and Biosystems Engineering]. To access the final edited and published work see [https://doi.org/ 10.1007/s00449-019-02243-1]During the last decades the understanding and prospects of enzyme-catalysed reactions
have been massively widened and there are a number of implemented large-scale enzymatic
processes mainly based in the use of commercial biocatalysts. As it might happen that the
same process can be successfully carried out by different commercial lipases, the election
of the biocatalyst must rely on productivity and economic considerations. This work
presents productiveness and direct operation cost evaluation as a key tool for the selection
between two commercial lipase catalysts, the versatile but expensive Novozym® 435 and a
much more economical option, Lipozyme® TL IM, in the synthesis of spermaceti, a mixture
of emollient esters with cosmetic applications. Proving that Novozym® 435 leads to
minimum savings of 10% with respect to the cheapest immobilized derivative, biocatalyst
cost does not appear to be the major contribution to the economics of the processes under
study, due to their great capacity to be recovered and reused. At laboratory scale, the
biggest economic investment is caused by substrates, which can be massively reduced at
industrial scale by using bulk reagents. In such case, energy cost may be the major
contribution to the process economy. This work proposes an optimized process ready to be
scaled-up in order to accurately determine the energetic requirements of the possible
industrial enzymatic synthesis
Esters in the Food and Cosmetic Industries: An Overview of the Reactors Used in Their Biocatalytic Synthesis
©2024. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
This document is the, Published, version of a Published Work that appeared in final form in Materials. To access the final edited and published work see https://doi.org/10.3390/ma17010268Esters are versatile compounds with a wide range of applications in various industries due to their unique properties and pleasant aromas. Conventionally, the manufacture of these compounds has relied on the chemical route. Nevertheless, this technique employs high temperatures and inorganic catalysts, resulting in undesired additional steps to purify the final product by removing solvent residues, which decreases environmental sustainability and energy efficiency. In accordance with the principles of “Green Chemistry” and the search for more environmentally friendly methods, a new alternative, the enzymatic route, has been introduced. This technique uses low temperatures and does not require the use of solvents, resulting in more environmentally friendly final products. Despite the large number of studies published on the biocatalytic synthesis of esters, little attention has been paid to the reactors used for it. Therefore, it is convenient to gather the scattered information regarding the type of reactor employed in these synthesis reactions, considering the industrial field in which the process is carried out. A comparison between the performance of the different reactor configurations will allow us to draw the appropriate conclusions regarding their suitability for each specific industrial application. This review addresses, for the first time, the above aspects, which will undoubtedly help with the correct industrial implementation of these processes
Sustainable Biocatalytic Synthesis of a Second-Generation Biolubricant
©. This manuscript version is made available under the CC-BY license http://creativecommons.org/licenses/by/4.0/
This document is the Published, version of a Published Work that appeared in final form in [Sustainability]. To access the final edited and published work see [https://doi.org/10.3390/su16041615]Background: Biolubricants represent a category of lubricating substances derived from
sustainable sources such as vegetable oils, animal fats, and other bio-based materials. They are considered
more environmentally friendly than mineral-based lubricants because they are biodegradable
and nontoxic. Biolubricants derived from vegetable oils or animal fats were used as first-generation
biolubricants. They have limited performance at extreme temperatures, both high and low, as well as
low oxidative stability. Substitution of the double bonds by branching improves the performance and
stability of the resulting second-generation biolubricants. Methods: In the past, the production of
these compounds has relied on the chemical pathway. This method involves elevated temperatures
and inorganic catalysts, leading to the necessity of additional purification steps, which decreases
environmental sustainability and energy efficiency. A more environmentally friendly alternative,
the enzymatic route, has been introduced, in accordance with the principles of “Green Chemistry”.
Results: In this paper, the esterification of 2-methylhexanoic acid with 2-octyl-1-dodecanol and its
optimization were developed for the first time. The synthesis was conducted within a jacketed batch
reactor connected to a thermostatic bath in a solvent-free reaction medium and using Lipozyme® 435
as biocatalyst. Conclusions: The high viscosity index value of this new hyperbranched ester (>200,
ASTM D2270) suggests that it may be an excellent biolubricant to be used under extreme temperature
conditions. Regarding sustainability, the main green metrics calculated point to an environmentally
friendly process
Green Production of a High-Value Branched-Chain Diester: Optimization Based on Operating Conditions and Economic and Sustainability Criteria
©. This manuscript version is made available under the CC-BY license http://creativecommons.org/licenses/by/4.0/
This document is the Published version of a Published Work that appeared in final form in [Applied Sciences]. To access the final edited and published work see [https://doi.org/ 10.3390/app13106177]Featured Application: In the last years, consumers’ and administrations’ demand for more sustainable products and processes has been increasing. This work develops a new sustainable way to obtain a branched ester for cosmetic applications (neopentylglycol dilaurate) and demonstrates that this new production route can be economically competitive. Branched-chain esters (BCEs) have found a large number of applications in cosmetics. Among them, neopentyl glycol dilaurate (NPGDL) stands out as an emollient, emulsifier, and skin-conditioning agent. This work presents the synthesis of NPGDL in a solvent-free medium using the two most common immobilized lipases: Novozym® 40086 (Rml) and Novozym® 435 (CalB). Results proved that the former biocatalyst has lower activity and certain temperature deactivation, although conversions ≥ 90% were obtained at 60 °C and 7.5% of catalyst. On the other hand, optimal reaction conditions for Novozym® 435 are 3.75% w/w of the immobilized derivative at 80 °C. Under optimal conditions, the process productivities were 0.105 and 0.169 kg NPGDL/L h, respectively. In order to select the best conditions for NPGDL production, studies on the reuse of the derivative and cost estimation have been performed. Economic study shows that biocatalytic processes can be competitive when lipases are reused for five cycles, yielding biocatalyst productivities of 56 and 122 kg NPGDL/kg biocatalyst using Novozym® 40086 and Novozym® 435, respectively. The final choice will be based on both economic and sustainability criteria. Green metric values using both biocatalysts are similar but the product obtained using Novozym® 40086 is 20% cheaper, making this alternative the best option
Neuropeptide precursor VGF is genetically associated with social anhedonia and underrepresented in the brain of major mental illness: its downregulation by DISC1
In a large Scottish pedigree, disruption of the gene coding for DISC1 clearly segregates with major depression, schizophrenia and related mental conditions. Thus, study of DISC1 may provide a clue to understand the biology of major mental illness. A neuropeptide precursor VGF has potent antidepressant effects and has been reportedly associated with bipolar disorder. Here we show that DISC1 knockdown leads to a reduction of VGF, in neurons. VGF is also downregulated in the cortices from sporadic cases with major mental disease. A positive correlation of VGF single-nucleotide polymorphisms (SNPs) with social anhedonia was also observed. We now propose that VGF participates in a common pathophysiology of major mental disease
Enhancement of PLA-PVA surface adhesion in bilayer assemblies by PLA aminolisation
Data Availability: The raw/processed data required to reproduce these
findings cannot be shared at this time due to legal or ethical reasons.Poly(lactic acid) (PLA) and poly(vinyl alcohol) (PVA) present complementary barrier properties, and their combination in multilayer assemblies (laminates) could provide materials with more effective barrier capacity for food packaging purposes. However, their low chemical affinity compromises adequate polymer adhesion. Surface free energy modification of thermo-processed PLA films through treatment with 1,6-hexanediamine was used to enhance adhesion with polar PVA aqueous solutions. Treatments of 1 and 3 min increased the polar component of the solid surface tension, while treatments above 10 min provoked a corrosive effect in the films structure. Extensibility analyses of PVA solutions loaded with carvacrol (15 wt.%) and different Tween 85 ratios on PLA-activated surfaces allowed the selection of the 1-min aminolysed surface for obtaining PLA-PVA bilayers, by casting PVA solutions on the PLA films. This study revealed that despite aminolisation enhancing the PLA surface affinity for aqueous PVA solutions, casting-obtained bilayers presented limited oxygen barrier effectiveness due to heterogeneous thickness of PVA layer in the laminates.The authors acknowledge the financial support provided by the Ministerio de Economia y Competitividad (MINECO) of Spain (project AGL2016-76699-R). The author A. Tampau thanks MINECO for the pre-doctoral research grant #BES-2014-068100.info:eu-repo/semantics/publishedVersio
The presence of extracellular matrix degrading metalloproteinases during fetal development of the intervertebral disc
Matrix metalloproteinases (MMPs) regulate connective tissue architecture and cell migration through extracellular matrix (ECM) degradation and are associated with both physiological and pathological processes. Although they are known to play a role in skeletal development, little is known about the role of MMPs in intervertebral disc (IVD) development. Sixteen fetal human lumbar spine segments, obtained at autopsy, were compared with five normal, non-fetal L4–L5 IVDs. Intensity and/or localization of immunohistochemical staining for MMP-1, -2, -3 and -14 were evaluated by three independent observers. MMP-2 production and activation was quantified by gelatin zymography. MMP-1 and -14 were abundantly present in the nucleus pulposus (NP) and notochordal (NC) cells of the fetal IVDs. In non-fetal IVDs, MMP-1 and -14 staining was significantly less intense (p = 0.001 and p < 0.001, respectively). MMP-3 was found in almost the entire IVD with no significant difference from non-fetal IVDs. MMP-2 staining in the NC and NP cells of the fetal IVD was moderate, but weak in the non-fetal IVD. Gelatin zymography showed a negative correlation of age with MMP-2 activity (p < 0.001). MMP-14 immunostaining correlated positively with MMP-2 activity (p = 0.001). For the first time, the presence of MMP-1, -2, -3 and -14 in the fetal human IVD is shown and the high levels of MMP-1, -2 and -14 suggest a role in the development of the IVD. In particular, the gradual decrease in MMP-2 activation during gestation pinpoints this enzyme as key player in fetal development, possibly through activation by MMP-1 and -14
Cerebrovascular events and outcomes in hospitalized patients with COVID-19: The SVIN COVID-19 Multinational Registry
© 2020 World Stroke Organization.[Background]: Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has been associated with a significant risk of thrombotic events in critically ill patients.
[Aim]: To summarize the findings of a multinational observational cohort of patients with SARS-CoV-2 and cerebrovascular disease.
[Methods]: Retrospective observational cohort of consecutive adults evaluated in the emergency department and/or admitted with coronavirus disease 2019 (COVID-19) across 31 hospitals in four countries (1 February 2020–16 June 2020). The primary outcome was the incidence rate of cerebrovascular events, inclusive of acute ischemic stroke, intracranial hemorrhages (ICH), and cortical vein and/or sinus thrombosis (CVST).
[Results]: Of the 14,483 patients with laboratory-confirmed SARS-CoV-2, 172 were diagnosed with an acute cerebrovascular event (1.13% of cohort; 1130/100,000 patients, 95%CI 970–1320/100,000), 68/171 (40.5%) were female and 96/172 (55.8%) were between the ages 60 and 79 years. Of these, 156 had acute ischemic stroke (1.08%; 1080/100,000 95%CI 920–1260/100,000), 28 ICH (0.19%; 190/100,000 95%CI 130–280/100,000), and 3 with CVST (0.02%; 20/100,000, 95%CI 4–60/100,000). The in-hospital mortality rate for SARS-CoV-2-associated stroke was 38.1% and for ICH 58.3%. After adjusting for clustering by site and age, baseline stroke severity, and all predictors of in-hospital mortality found in univariate regression (p < 0.1: male sex, tobacco use, arrival by emergency medical services, lower platelet and lymphocyte counts, and intracranial occlusion), cryptogenic stroke mechanism (aOR 5.01, 95%CI 1.63–15.44, p < 0.01), older age (aOR 1.78, 95%CI 1.07–2.94, p ¼ 0.03), and lower lymphocyte count on admission (aOR 0.58, 95%CI 0.34–0.98, p ¼ 0.04) were the only independent predictors of mortality among patients with stroke and COVID-19.
[Conclusions]: COVID-19 is associated with a small but significant risk of clinically relevant cerebrovascular events, particularly ischemic stroke. The mortality rate is high for COVID-19-associated cerebrovascular complications; therefore, aggressive monitoring and early intervention should be pursued to mitigate poor outcomes