scholarly journals Analysis of the lipid extraction performance in a cascade process for Scenedesmus almeriensis biorefinery

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
I. Papachristou ◽  
S. Akaberi ◽  
A. Silve ◽  
E. Navarro-López ◽  
R. Wüstner ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Proteolytic Enzymes ◽  
Lipid Extraction ◽  
Protein Hydrolysis ◽  
Cascade Process ◽  
Disruptive Effect ◽  
Total Lipids ◽  
Water Fraction ◽  
Wide Range ◽  
Scenedesmus Almeriensis

Abstract Background Microalgae have attracted considerable interest due to their ability to produce a wide range of valuable compounds. Pulsed Electric Fields (PEF) has been demonstrated to effectively disrupt the microalgae cells and facilitate intracellular extraction. To increase the commercial viability of microalgae, the entire biomass should be exploited with different products extracted and valorized according to the biorefinery scheme. However, demonstrations of multiple component extraction in series are very limited in literature. This study aimed to develop an effective lipid extraction protocol from wet Scenedesmus almeriensis after PEF-treatment with 1.5 MJ·kgDW−1. A cascade process, i.e., the valorization of several products in row, was tested with firstly the collection of the released carbohydrates in the water fraction, then protein enzymatic hydrolysis and finally lipid extraction. Biomass processed with high pressure homogenization (HPH) on parallel, served as benchmark. Results Lipid extraction with ethanol:hexane (1:0.41 vol/vol) offered the highest yields from the different protocols tested. PEF-treatment promoted extraction with almost 70% of total lipids extracted against 43% from untreated biomass. An incubation step after PEF-treatment, further improved the yields, up to 83% of total lipids. Increasing the solvent volume by factor 2 offered no improvement. In comparison, extraction with two other systems utilizing only ethanol at room temperature or elevated at 60 °C were ineffective with less than 30% of total lipids extracted. Regarding cascade extraction, carbohydrate release after PEF was detected albeit in low concentrations. PEF-treated samples displayed slightly better kinetics during the enzymatic protein hydrolysis compared to untreated or HPH-treated biomass. The yields from a subsequent lipid extraction were not affected after PEF but were significantly increased for untreated samples (66% of total lipids), while HPH displayed the lowest yields (~ 49% of total lipids). Conclusions PEF-treatment successfully promoted lipid extraction from S. almeriensis but only in combination with a polar:neutral co-solvent (ethanol:hexane). After enzymatic protein hydrolysis in cascade processing; however, untreated biomass displayed equal lipid yields due to the disruptive effect of the proteolytic enzymes. Therefore, the positive impact of PEF in this scheme is limited on the improved reaction kinetics exhibited during the enzymatic hydrolysis step.

scholarly journals Rapid extraction of total lipids and lipophilic POPs from all EU-regulated foods of animal origin: Smedes’ method revisited and enhanced

2020 ◽  
Vol 32 (1) ◽  
Author(s):  
Johannes Haedrich ◽  
Claudia Stumpf ◽  
Michael S. Denison
Keyword(s):  
Milk Fat ◽  
Lipid Extraction ◽  
Poultry Meat ◽  
Animal Origin ◽  
Infant Food ◽  
Total Lipids ◽  
Analytical Results ◽  
Official Control ◽  
Wide Range ◽  
Chicken Eggs

Abstract Background Persistent organic pollutants (POPs) such as dioxins, dioxin-like chemicals and non-dioxin-like PCBs causing adverse effects to human health bio-accumulate through the food web due to their affinity for adipose tissues. Foods of animal origin are therefore the main contributors to human dietary exposure. The European Union’s (EU) food safety policy requires checking of a wide range of samples for compliance with legal limits on a regular basis. Several methods of varying efficiency are applied by official control laboratories for extraction of the different classes of lipids and associated POPs, bound to animal tissue and animal products in varying degrees, sometimes leading to discrepancies especially in fresh weight based analytical results. Results Starting from Smedes’ lipid extraction from marine tissue, we optimized the extraction efficiency for both lipids and lipophilic pollutants, abandoning the time-consuming centrifugation step. The resulting modified Smedes extraction (MSE) method was validated based on multiple analyses of a large number of real-world samples, matrix calibration and performance assessment in proficiency testing utilizing both instrumental and bioanalytical methodologies. Intermediate precision in 12 different foods was below 3% in chicken eggs, egg powder, animal fat, fish, fish oil, poultry, whole milk, milk fat and milk powder, and below 5% in bovine meat, liver, and infant food. In comparison to Twisselmann hot extraction, results presented here show an increased efficiency of MSE by + 25% for bovine liver, + 14% for chicken eggs, + 13% for poultry meat, + 12% for fish, 8% for bovine meat, and 6% for infant food. Conclusions For the first time, a fast and reliable routine method is available that enables the analyst to reproducibly extract "total" lipids from any EU-regulated food sample of animal origin within 6 to 8 min. Increased efficiency translates into a considerable increase in both lipid and wet weight-based analytical results measured for associated POPs, reducing the risk of false non-compliant results. Compared to a 4 h Twisselmann extraction, the extraction of 1000 samples using MSE would result in annual savings of about 250 h or 32 working days. Our MSE procedure contributes to the European Commission's objective of harmonizing analytical results across the EU generated according to Commission Regulation (EU) 2017/644.

scholarly journals Individual Expression of Hepatitis A Virus 3C Protease Induces Ferroptosis in Human Cells In Vitro

2021 ◽  
Vol 22 (15) ◽  
pp. 7906
Author(s):  
Alexey A. Komissarov ◽  
Maria A. Karaseva ◽  
Marina P. Roschina ◽  
Andrey V. Shubin ◽  
Nataliya A. Lunina ◽  
...  
Keyword(s):  
Cell Death ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Proteolytic Enzymes ◽  
Morphological Changes ◽  
Human Cells ◽  
Mitochondrial Potential ◽  
3C Protease ◽  
Wide Range

Regulated cell death (RCD) is a fundamental process common to nearly all living beings and essential for the development and tissue homeostasis in animals and humans. A wide range of molecules can induce RCD, including a number of viral proteolytic enzymes. To date, numerous data indicate that picornaviral 3C proteases can induce RCD. In most reported cases, these proteases induce classical caspase-dependent apoptosis. In contrast, the human hepatitis A virus 3C protease (3Cpro) has recently been shown to cause caspase-independent cell death accompanied by previously undescribed features. Here, we expressed 3Cpro in HEK293, HeLa, and A549 human cell lines to characterize 3Cpro-induced cell death morphologically and biochemically using flow cytometry and fluorescence microscopy. We found that dead cells demonstrated necrosis-like morphological changes including permeabilization of the plasma membrane, loss of mitochondrial potential, as well as mitochondria and nuclei swelling. Additionally, we showed that 3Cpro-induced cell death was efficiently blocked by ferroptosis inhibitors and was accompanied by intense lipid peroxidation. Taken together, these results indicate that 3Cpro induces ferroptosis upon its individual expression in human cells. This is the first demonstration that a proteolytic enzyme can induce ferroptosis, the recently discovered and actively studied type of RCD.

STUDYING OF ACTIVITY OF INHIBITORS OF PROTEOLYTIC ENZYMES IN PRODUCTS OF PROCESSING OF GRAIN HARICOT (PHASEOLUS VULGARIS)

2018 ◽  
Author(s):  
Н.Т. ШАМКОВА ◽  
А.М. АБДУЛХАМИД
Keyword(s):  
Phaseolus Vulgaris ◽  
Liquid Medium ◽  
Proteolytic Enzymes ◽  
Trypsin Inhibitors ◽  
Milk Whey ◽  
Fine Grinding ◽  
Bean Flour ◽  
Wide Range ◽  
Mashed Potatoes

Определено содержание ингибиторов протеолитических ферментов в фасолевой муке, в пюре из зерновой фасоли, сваренной в воде, и в пюре из зерновой фасоли, сваренной после замачивания в воде в молочной сыворотке. Обосновано использование молочной сыворотки в качестве жидкой среды для варки зерновой фасоли после замачивания. Разработана технология полуфабриката в виде фасолевого пюре, предусматривающая замачивание фасоли в воде, варку в молочной сыворотке, грубое измельчение доведенной до готовности фасоли, последующее тонкое измельчение и охлаждение. Установлено, что в фасолевом пюре активность ингибиторов трипсина значительно ниже, чем в муке из фасоли, что делает пюре более предпочтительным полуфабрикатом для производства широкого ассортимента кулинарной продукции. The content of inhibitors of proteolytic enzymes in bean flour, in puree from beans harvested in water and in puree from cereal beans welded in milk whey after soaking in water is determined. The use of whey as a liquid medium for cooking grain beans after soaking is substantiated. The technology of semi-finished product in the form of bean puree, providing for soaking beans in water, cooking in milk whey, coarse grinding of the bean brought to the ready, subsequent fine grinding and cooling is developed. It has been found that the activity of trypsin inhibitors in bean puree is much lower than in bean flour, which makes mashed potatoes a more preferred semi-finished product for the production of a wide range of culinary products.

scholarly journals Digestive Alkaline Proteases from Zosterisessor ophiocephalus, Raja clavata, and Scorpaena scrofa: Characteristics and Application in Chitin Extraction

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Rim Nasri ◽  
Islem Younes ◽  
Imen Lassoued ◽  
Sofiane Ghorbel ◽  
Olfa Ghorbel-Bellaaj ◽  
...  
Keyword(s):  
Proteolytic Enzymes ◽  
Tween 20 ◽  
Sodium Perborate ◽  
Alkaline Proteases ◽  
Shrimp Waste ◽  
Wide Range ◽  
Raja Clavata ◽  
Shrimp Wastes ◽  
Scorpaena Scrofa ◽  
Zosterisessor Ophiocephalus

The aim of this work was to study some biochemical characteristics of crude alkaline protease extracts from the viscera of goby (Zosterisessor ophiocephalus), thornback ray (Raja clavata), and scorpionfish (Scorpaena scrofa), and to investigate their applications in the deproteinization of shrimp wastes. At least four caseinolytic proteases bands were observed in zymogram of each enzyme preparation. The optimum pH for enzymatic extracts activities of Z. ophiocephalus, R. clavata, and S. scrofa were 8.0-9.0, 8.0, and 10.0, respectively. Interestingly, all the enzyme preparations were highly stable over a wide range of pH from 6.0 to 11.0. The optimum temperatures for enzyme activity were 50∘C for Z. ophiocephalus and R. clavata and 55∘C for S. scrofa crude alkaline proteases. Proteolytic enzymes showed high stability towards non-ionic surfactants (5% Tween 20, Tween 80, and Triton X-100). In addition, crude proteases of S. scrofa, R. clavata, and Z. ophiocephalus were found to be highly stable towards oxidizing agents, retaining 100%, 70%, and 66%, respectively, of their initial activity after incubation for 1 h in the presence of 1% sodium perborate. They were, however, highly affected by the anionic surfactant SDS. The crude alkaline proteases were tested for the deproteinization of shrimp waste in the preparation of chitin. All proteases were found to be effective in the deproteinization of shrimp waste. The protein removals after 3 h of hydrolysis at 45∘C with an enzyme/substrate ratio (E/S) of 10 were about 76%, 76%, and 80%, for Z. ophiocephalus, R. clavata, and S. scrofa crude proteases, respectively. These results suggest that enzymatic deproteinization of shrimp wastes by fish endogenous alkaline proteases could be applicable to the chitin production process.

scholarly journals ENZYMATIC HYDROLYSIS KINETIC ANALYSIS OF THE VARIOUS SOURCE PROTEINS

2013 ◽  
Vol 17 (2) ◽  
pp. 15-20
Author(s):  
Aleksey Vinnov ◽  
Dmitro Prasol
Keyword(s):  
Chemical Composition ◽  
Enzymatic Hydrolysis ◽  
Kinetic Analysis ◽  
Protein Concentration ◽  
Proteolytic Enzymes ◽  
Sunflower Meal ◽  
Microbial Enzyme ◽  
Michaelis Constants ◽  
Plant Enzyme ◽  
Complex Dispersion

Abstract The chemical composition marble goby and sunflower meal is presented. The experimental results of enzymatic hydrolysis velocity in dependence of the protein concentration in substrate systems are set. Michaelis constants values for industrial proteolytic enzymes Corolase ® L10 and Corolase ® L7089 are calculated. The application experimental - theoretical kinetic analysis for protease / proteins congeniality determine in complex dispersion substrate systems expediency was confirmed. It is determined that microbial enzyme drag Corolase ® L7089 has a higher congeniality to proteins of all the tested substrates than plant enzyme drag Corolase ® L10

scholarly journals Approximate multifractal correlation and products of universal multifractal fields, with application to rainfall data

2020 ◽  
Vol 27 (1) ◽  
pp. 133-145
Author(s):  
Auguste Gires ◽  
Ioulia Tchiguirinskaia ◽  
Daniel Schertzer
Keyword(s):  
Liquid Water Content ◽  
Relative Strength ◽  
Rainfall Data ◽  
Second Step ◽  
Cascade Process ◽  
Suggested Approach ◽  
Single Scale ◽  
Starting Point ◽  
Wide Range ◽  
Joint Multifractal Analysis

Abstract. Universal multifractals (UMs) have been widely used to simulate and characterize, with the help of only two physically meaningful parameters, geophysical fields that are extremely variable across a wide range of scales. Such a framework relies on the assumption that the underlying field is generated through a multiplicative cascade process. Derived analysis techniques have been extended to study correlations between two fields not only at a single scale and for a single statistical moment as with the covariance, but across scales and for all moments. Such a framework of joint multifractal analysis is used here as a starting point to develop and test an approach enabling correlations between UM fields to be analysed and approximately simulated. First, the behaviour of two fields consisting of renormalized multiplicative power law combinations of two UM fields is studied. It appears that in the general case the resulting fields can be well approximated by UM fields with known parameters. Limits of this approximation will be quantified and discussed. Techniques to retrieve the UM parameters of the underlying fields as well as the exponents of the combination have been developed and successfully tested on numerical simulations. In a second step tentative correlation indicators are suggested. Finally the suggested approach is implemented to study correlation across scales of detailed rainfall data collected with the help of disdrometers of the Fresnel platform of Ecole des Ponts ParisTech (see available data at https://hmco.enpc.fr/portfolio-archive/taranis-observatory/, last access: 12 March 2020). More precisely, four quantities are used: the rain rate (R), the liquid water content (LWC) and the total drop concentration (Nt) along with the mass weighed diameter (Dm), which are commonly used to characterize the drop size distribution. Correlations across scales are quantified. Their relative strength (very strong between R and LWC, strong between DSD features and R or LWC, almost null between Nt and Dm) is discussed.

Steps in the reactions of proteolytic enzymes with their substrates

1970 ◽  
Vol 257 (813) ◽  
pp. 105-110 ◽  
Keyword(s):  
Active Sites ◽  
Dissociation Constants ◽  
Proteolytic Enzymes ◽  
Substrate Binding ◽  
Hydrolytic Enzymes ◽  
Dimensional Structure ◽  
Chemical Information ◽  
Substrate Interaction ◽  
Enzyme Substrate ◽  
Wide Range

Kinetic experiments should be designed to answer specific questions about a reaction mechanism. The present paper is intended to show how a number of specific questions have been answered. Chymotrypsin and trypsin are mainly used to illustrate the different approaches, but many of the arguments used are equally applicable to the reactions of other hydrolytic enzymes with serine-OH or cysteine-SH at the active site. T he recognition of serine-OH and cysteine-SH as essential groups at the active sites of different hydrolytic enzymes did not rest on kinetic evidence. This was deduced from the correlation of enzyme activity with the extent of modification of specially reactive groups. The investigation of proton dissociation equilibria and the assignment of dissociation constants to groups with specified functions in substrate binding, catalysis or protein conformation was the first objective of serious kinetic studies of enzyme reactions. Steady state rate measurements over a wide range of pH showed that groups with p K 6.25 and 6.85 respectively are involved in the catalytic activity of trypsin and chymotrypsin with certain specific substrates (Hammond & Gutfreund 1955). In the case of chymotrypsin it was also shown by Hammond & Gutfreund (1955) that a group with a more alkaline pK is involved in substrate binding. This latter group was subsequently identified and its function was elucidated through the elegant experiments of Oppenheimer, Labouresse & Hess (1966). The identification of histidine as the group with p K A near neutrality, involved in the catalytic mechanism of trypsin and chymotrypsin, was subsequently confirmed by direct chemical methods by Schoelmann & Shaw (1963). Only kinetic analysis can demonstrate the involvement of proton donors or acceptors with specific properties in enzyme-substrate interaction or in catalysis. The clear identification of chemical groups capable of performing such functions is coming from the crystallographic analysis of the three-dimensional structure at the site of enzyme-substrate interaction, as illustrated in other papers presented in this discussion. Very interesting chemical information is obtained when the effect of structure on reactivity is synthesized from the composite of crystallographic and kinetic data.

SUSCEPTIBILITY OF PROTEINS USED IN CALF MILK REPLACERS TO HYDROLYSIS BY VARIOUS PROTEOLYTIC ENZYMES

1980 ◽  
Vol 60 (4) ◽  
pp. 907-914 ◽  
Author(s):  
K. J. JENKINS ◽  
S. MAHADEVAN ◽  
D. B. EMMONS
Keyword(s):  
Trichloroacetic Acid ◽  
Proteolytic Enzymes ◽  
Milk Proteins ◽  
In Vitro Study ◽  
Enzyme Treatment ◽  
Protein Hydrolysis ◽  
Protein Substrates ◽  
Optimum Ph ◽  
Milk Replacers

An in vitro study was conducted to assess the hydrolytic susceptibility of various milk and non-milk proteins (soybean, rapeseed, fish) used in calf milk replacers to endogenous and commercial proteolytic enzymes. Extent of protein hydrolysis (%) was calculated from the reduced amount of protein precipitated by 10% trichloroacetic acid following enzyme treatment. All of the enzymes tested hydrolyzed the milk proteins more extensively than the non-milk proteins both at their optimum pH, and at the pH (6.1) of calf abomasal contents immediately after feeding. At both optimum pH and pH 6.1, the highest average hydrolysis value for all protein substrates was obtained with pronase followed by papain, trypsin, pancreatin, chymotrypsin, Mucor miehei rennet andchymosin (calf rennet). All substrates were hydrolyzed extensively by pepsin at pH 2.0 but, as expected, very little hydrolysis occurred with this enzyme atpH6.1.

scholarly journals Development of a recipe for a multicomponent mixture "Solodok +" to improve the consumer properties of bakery products

ScienceRise ◽  
2021 ◽  
pp. 18-24
Author(s):  
Olena Bilyk ◽  
Yulia Bondarenko ◽  
Oksana Kochubei-Lytvynenko ◽  
Liudmyla Burchenko
Keyword(s):  
Multicomponent Mixture ◽  
Proteolytic Enzymes ◽  
Experimental Studies ◽  
Optimal Dose ◽  
Bakery Products ◽  
Milk Whey ◽  
Baked Goods ◽  
Wide Range ◽  
Scientific Results ◽  
Technological Product

The object of research is the technology of bakery products enriched with a mixture of germinated grains of wheat, corn, barley and oats. Investigated problem: The problem of using a mixture of germinated grains is the formation of a closure sticky crumb in baked goods with a mixture. The reason for this is the high activity in the mixture of amylolytic and proteolytic enzymes. The solution to the problem consists in the developed multicomponent mixture (MM) to improve the consumer properties of bakery products, the formulation of which includes 15 % of the flour mass of the germinated grain mixture. Main scientific results: On the basis of experimental studies, the formulation of the "Solodok+" multicomponent mixture has been developed. The mixture contains: chicory inulin, dry milk whey enriched with Mg and Mn, apple pectin, phosphatide concentrate, enzyme preparation Deltamalt FN-A 50 and ascorbic acid. The optimal dose of the "Solodok+" MM for bakery products is 2.5 % by weight of flour. The area of practical use of the research results: "Solodok+" MM is recommended to be used in the production of bakery products enriched with sprouted grains at enterprises of the bakery industry of various capacities. An innovative technological product: "Solodok+" MM helps not only to reduce the stickiness of the crumb, improve its porosity, increase the volume of products, but also lengthen the freshness of unpackaged products. Scope of application of the innovative technological product: Bakery products with a mixture of sprouted grains and "Solodok+" MM have increased nutritional value, high consumer properties and are intended for a wide range of consumers.

scholarly journals Correlation between the emulsion oligomerization parameters for C9 fraction and the characteristics of hydrocarbon resins

2021 ◽  
Vol 3 (6 (111)) ◽  
pp. 6-11
Author(s):  
Roman Subtelnyy ◽  
Dariia Kichura ◽  
Bohdan Dzinyak
Keyword(s):  
Reaction Temperature ◽  
Softening Temperature ◽  
Oil Refining ◽  
Variable Yield ◽  
Water Fraction ◽  
Film Forming ◽  
Wide Range ◽  
Bromine Number ◽  
The Relationship ◽  
Mean Molecular Weight

This paper investigates the production of hydrocarbon resins by emulsion oligomerization of the С9 fraction hydrocarbons in liquid by-products of oil refining. Such oligomers have a wide range of applications as film-forming agents in paints and anti-color coatings. Emulsion oligomerization was carried out using emulsifiers of the first and second kind. The study was performed at different values of the reaction temperature of the reaction duration, the intensity of agitation; concentrations of the emulsifier; С9:water fraction ratio. The resulting products were estimated according to the following indicators: the yield, unsaturation degree, softening temperature, mean molecular weight, color. Statistical analysis was carried out, the correlation of parameters of emulsion oligomerization and the yield and characteristics of oligomers was established. Given that, it would be possible to establish the optimal conditions for emulsion oligomerization and predict the properties of the products obtained. Specifically, it was established that the yield of hydrocarbon resins does not correlate with the reaction temperature (0.15 and 0.30) and the concentration of emulsifiers (0.08 and 0.03). It was proven that in the intervals studied the variable yield of oligomers depends on the duration of the reaction (correlation 0.88 and 0.81). In the case of oligomerization in the reverse emulsion, a significant correlation with the yield is also demonstrated by agitation intensity (0.51) and a С9:water fraction ratio (0.51). That has made it possible to derive an equation of the yield multiple linear regression dependent on the most significant process parameters. The high values of the yield and bromine number correlation (0.94 and 0.93) give grounds to argue about the progress of oligomerization reaction. The relationship among the characteristics of oligomers has been confirmed. This indicates the possibility of directed adjustment of certain characteristics of hydrocarbon resins.

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