APPLICATION OF EXTRACTION METHOD FOR ISOLATION OF BIOGENIC SURFACE-ACTIVE RHAMNOLIPIDS

Author(s):  
Іlоna KARPENKO ◽  
◽  
Galyna MIDYANA ◽  
Olena KARPENKO ◽  
Igor SEMENIUK ◽  
...  

The priority task of modern biotechnology is development of the rational technologies for the microbial synthesis of practically important products. Among these products, a significant place belongs to surfactants (biosurfactants), which are widely used in many sectors of the economy. The most problematic stage of the biosurfactants production is isolation from the post fermentative cultural liquid of bacteria-producers. Improving the efficiency of the biosurfactants production is highly dependent on rational approaches to the target products isolation. In this regard, there is an increasing need for rational, scientifically substantiated methods for their isolation and purification. Therefore, the aim of the presented work was to determine the optimal extractants for the isolation of rhamnolipid surfactants – metabolites of bacteria of Pseudomonas sp. PS-17 strain. For this purpose, the extraction process of rhamnolipids from the post fermentative cultural liquid supernatant has been investigated. The optimal extractants were selected among 13 organic solvents of different nature. Processing of the obtained experimental data by the method of multi-parameter equations of linearity of free energies (modified Koppel-Palm equation) made it possible to establish the relationship between the physicochemical properties of the extractants and amounts of the biosurfactants which were isolated from cultural liquid supernatant. It was shown that the data on the rhamnolipids extraction are adequately associated with the physicochemical characteristics of the solvents using a six-parameter linear equation. It was determined that the polarizability and molar volume are the main properties of solvents that affect the extraction process. The best extractants for the rhamnolipids isolation from cultural liquid supernatant of the Pseudomonas sp. PS-17 strain are the ethers. It can be explained by the presence of a lone pair of the electrons of oxygen in its molecule. The obtained results of the study are of scientific interest for isolation of the important and perspective biotechnological products – surface-active substances.

2021 ◽  
Vol 22 (7) ◽  
pp. 3634
Author(s):  
Beata Szefler ◽  
Przemysław Czeleń ◽  
Przemysław Krawczyk

Platinum compounds have found wide application in the treatment of various types of cancer and carboplatin is one of the main platinum-based drugs used as antitumor agents. The anticancer activity of carboplatin arises from interacting with DNA and inducing programmed cell death. However, such interactions may occur with other chemical compounds, such as vitamins containing aromatic rings with lone-pair orbitals, which reduces the anti-cancer effect of carboplatin. The most important aspect of the conducted research was related to the evaluation of carboplatin affinity to vitamins from the B group and the potential impact of such interactions on the reduction of therapeutic capabilities of carboplatin in anticancer therapy. Realized computations, including estimation of Gibbs Free Energies, allowed for the identification of the most reactive molecule, namely vitamin B6 (pyridoxal phosphate). In this case, the computational estimations indicating carboplatin reactivity were confirmed by spectrophotometric measurements.


2016 ◽  
Vol 69 (11) ◽  
pp. 1254 ◽  
Author(s):  
Jiequn Wu ◽  
Tianxiang Yin ◽  
Shaoxiong Shi ◽  
Weiguo Shen

The systematic investigation of the aggregation behaviours of newly synthesised surface-active ionic liquids 1-alkyl-3-methylimidazolium bis(2-ethylhexyl)sulfosuccinate ([Cnmim][AOT], n = 2, 3, 5, 6, 7) by various techniques is reported. The critical aggregation concentrations (CACs) and the standard Gibbs free energies of aggregation () were determined from measurements on conductivity, fluorescence, and surface tension, which suggested a stronger self-assembly ability in the bulk solution for [Cnmim][AOT] surfactants with longer alkyl chain cations. An interesting structure transition driven by the penetration of the imidazolium cation into the aggregate when n > 4 was found by analysis of the variations of the values of CAC, , the degree of counter ion binding (β), and the micropolarity (I1/I3) immediately after the CAC with changing alkyl chain length of the imidazolium cation, which was further confirmed by 1H NMR measurements.


2012 ◽  
Vol 39 (11) ◽  
pp. 21-27 ◽  
Author(s):  
L.I. Shal'nova ◽  
N.A. Lavrov ◽  
A.F. Nikolaev

The physicochemical properties and the formation, stability, and dissociation constants of complexes of poly acids with organic bases possessing physiological activity were determined by methods of potentiometric titration, conductometry, and equilibrium dialysis, and by biological methods. The relationship between the level of physicochemical characteristics of complexes and the possibility of predicting the prolonged pharmacological (antimicrobial, anaesthetising) action of physiologically active substances in complexes with polymers was established.


Microbiology ◽  
2005 ◽  
Vol 151 (5) ◽  
pp. 1403-1408 ◽  
Author(s):  
Daan van den Broek ◽  
Thomas F. C. Chin-A-Woeng ◽  
Guido V. Bloemberg ◽  
Ben J. J. Lugtenberg

Pseudomonas sp. strain PCL1171 undergoes reversible colony phase variation between opaque phase I and translucent phase II colonies, which is dependent on spontaneous mutations in the regulatory genes gacA and gacS. Mutation of the mutS gene and constitutive expression of rpoS increases the frequency at which gac mutants appear 1000- and 10-fold, respectively. Experiments were designed to study the relationship between gacS, rpoS and mutS. These studies showed that (i) a functional gac system is required for the expression of rpoS, (ii) RpoS suppresses the expression of mutS and therefore increases the frequency of gac mutants, and (iii) upon mutation of rpoS and gacS, the expression of mutS is increased. Mutation of gacS abolishes suppression of mutS expression in stationary growth, suggesting that additional gac-dependent factors are involved in this suppression. In conclusion, inefficient mutation repair via MutS, of which the expression is influenced by gacA/S itself and by rpoS in combination with other factors, contributes to the high frequency of mutations accumulating in gacA/S. The role of RpoS in the growth advantage of a gac mutant was analysed, and mutation of rpoS only reduced the length of the lag phase, but did not affect the growth rate, suggesting a role for both RpoS and a reduction of metabolic load in the growth advantage of a gac mutant.


2015 ◽  
Vol 6 (3) ◽  
pp. 423-425
Author(s):  
Justo Corti Varela

This section aims to update readers on decisions related to marketing products of modern biotechnology (e.g., GMOs, animal clones) at EU level and on national measures concerning their production. Special attention is devoted to problems of competence between Member States and the EU in regulating biotechnology issues; the institutional dynamics of decision making regarding products derived frommodern biotechnology; the relationship between the EFSA and the EU institutions on green biotech-related issues; the evolution of EU regulatory framework and of national attitudes towards the risks and benefits of biotechnology derived products and their production. This section will also delve into the interaction between the EU legislation and WTO law regarding advances in the application of biotechnology within the agri–food value chain.


Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 235 ◽  
Author(s):  
Rubén R. López ◽  
Ixchel Ocampo ◽  
Luz-María Sánchez ◽  
Anas Alazzam ◽  
Karl-F. Bergeron ◽  
...  

Liposomes nanoparticles (LNPs) are vesicles that encapsulate drugs, genes, and imaging labels for advanced delivery applications. Control and tuning liposome physicochemical characteristics such as size, size distribution, and zeta potential are crucial for their functionality. Liposome production using micromixers has shown better control over liposome characteristics compared with classical approaches. In this work, we used our own designed and fabricated Periodic Disturbance Micromixer (PDM). We used Design of Experiments (DoE) and Response Surface Methodology (RSM) to statistically model the relationship between the Total Flow Rate (TFR) and Flow Rate Ratio (FRR) and the resulting liposomes physicochemical characteristics. TFR and FRR effectively control liposome size in the range from 52 nm to 200 nm. In contrast, no significant effect was observed for the TFR on the liposomes Polydispersity Index (PDI); conversely, FRR around 2.6 was found to be a threshold between highly monodisperse and low polydispersed populations. Moreover, it was shown that the zeta potential is independent of TFR and FRR. The developed model presented on the paper enables to pre-establish the experimental conditions under which LNPs would likely be produced within a specified size range. Hence, the model utility was demonstrated by showing that LNPs were produced under such conditions.


Mathematics ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 689
Author(s):  
Won Keun Min

We introduce the notion of the reduct of soft contexts, which is a special notion of a consistent set for soft contexts. Then, we study its properties and show that this notion is well explained by the two classes, 1 0 and 2 0 , of independent attributes. In particular, we describe in detail how to extract a reduct from a given consistent set. Then, based on this extraction process, we propose a six-step method for constructing a reduct from a given consistent set. Additionally, to apply this method to formal contexts, we examine the relationship between the reducts of a given formal context and the reducts of the associated soft context. We finally illustrate the process of obtaining reducts in a formal context using this relationship and the six-step method using an example.


2010 ◽  
Vol 1 (2) ◽  
pp. 151-152
Author(s):  
Vessela Hristova

This section aims to update readers on decisions related to marketing products of modern biotechnology (e.g., GMOs, animal clones) at EU level and on national measures concerning their production. Special attention is devoted to problems of competence between Member States and the EU in regulating biotechnology issues; the institutional dynamics of decision making regarding products derived from modern biotechnology; the relationship between the EFSA and the EU institutions on green biotech-related issues; the evolution of EU regulatory framework and of national attitudes towards the risks and benefits of biotechnology derived products and their production. This section will also delve into the interaction between the EU legislation and WTO law regarding advances in the application of biotechnology within the agri-food value chain.


2011 ◽  
Vol 57 (8) ◽  
pp. 623-628 ◽  
Author(s):  
Nagissa Mahmoudi ◽  
Greg F. Slater ◽  
Roberta R. Fulthorpe

Molecular characterization of the microbial populations of soils and sediments contaminated with polycyclic aromatic hydrocarbons (PAHs) is often a first step in assessing intrinsic biodegradation potential. However, soils are problematic for molecular analysis owing to the presence of organic matter, such as humic acids. Furthermore, the presence of contaminants, such as PAHs, can cause further challenges to DNA extraction, quantification, and amplification. The goal of our study was to compare the effectiveness of four commercial soil DNA extraction kits (UltraClean Soil DNA Isolation kit, PowerSoil DNA Isolation kit, PowerMax Soil DNA Isolation kit, and FastDNA SPIN kit) to extract pure, high-quality bacterial and eukaryotic DNA from PAH-contaminated soils. Six different contaminated soils were used to determine if there were any biases among the kits due to soil properties or level of contamination. Extracted DNA was used as a template for bacterial 16S rDNA and eukaryotic 18S rDNA amplifications, and PCR products were subsequently analyzed using denaturing gel gradient electrophoresis (DGGE). We found that the FastDNA SPIN kit provided significantly higher DNA yields for all soils; however, it also resulted in the highest levels of humic acid contamination. Soil texture and organic carbon content of the soil did not affect the DNA yield of any kit. Moreover, a liquid–liquid extraction of the DNA extracts found no residual PAHs, indicating that all kits were effective at removing contaminants in the extraction process. Although the PowerSoil DNA Isolation kit gave relatively low DNA yields, it provided the highest quality DNA based on successful amplification of both bacterial and eukaryotic DNA for all six soils. DGGE fingerprints among the kits were dramatically different for both bacterial and eukaryotic DNA. The PowerSoil DNA Isolation kit revealed multiple bands for each soil and provided the most consistent DGGE profiles among replicates for both bacterial and eukaryotic DNA.


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