Tapping the Role of Microbial Biosurfactants in Pesticide Remediation: An Eco-Friendly Approach for Environmental Sustainability

Pesticides are used indiscriminately all over the world to protect crops from pests and pathogens. If they are used in excess, they contaminate the soil and water bodies and negatively affect human health and the environment. However, bioremediation is the most viable option to deal with these pollutants, but it has certain limitations. Therefore, harnessing the role of microbial biosurfactants in pesticide remediation is a promising approach. Biosurfactants are the amphiphilic compounds that can help to increase the bioavailability of pesticides, and speeds up the bioremediation process. Biosurfactants lower the surface area and interfacial tension of immiscible fluids and boost the solubility and sorption of hydrophobic pesticide contaminants. They have the property of biodegradability, low toxicity, high selectivity, and broad action spectrum under extreme pH, temperature, and salinity conditions, as well as a low critical micelle concentration (CMC). All these factors can augment the process of pesticide remediation. Application of metagenomic and in-silico tools would help by rapidly characterizing pesticide degrading microorganisms at a taxonomic and functional level. A comprehensive review of the literature shows that the role of biosurfactants in the biological remediation of pesticides has received limited attention. Therefore, this article is intended to provide a detailed overview of the role of various biosurfactants in improving pesticide remediation as well as different methods used for the detection of microbial biosurfactants. Additionally, this article covers the role of advanced metagenomics tools in characterizing the biosurfactant producing pesticide degrading microbes from different environments.

Double-Chain Cationic Surfactants: Swelling, Structure, Phase Transitions and Additive Effects

Double-chain amphiphilic compounds, including surfactants and lipids, have broad significance in applications like personal care and biology. A study on the phase structures and their transitions focusing on dioctadecyldimethylammonium chloride (DODAC), used inter alia in hair conditioners, is presented. The phase behaviour is dominated by two bilayer lamellar phases, Lβ and Lα, with “solid” and “melted” alkyl chains, respectively. In particular, the study is focused on the effect of additives of different polarity on the phase transitions and structures. The main techniques used for investigation were differential scanning calorimetry (DSC) and small- and wide-angle X-ray scattering (SAXS and WAXS). From the WAXS reflections, the distance between the alkyl chains in the bilayers was obtained, and from SAXS, the thicknesses of the surfactant and water layers. The Lα phase was found to have a bilayer structure, generally found for most surfactants; a Lβ phase made up of bilayers with considerable chain tilting and interdigitation was also identified. Depending mainly on the polarity of the additives, their effects on the phase stabilities and structure vary. Compounds like urea have no significant effect, while fatty acids and fatty alcohols have significant effects, but which are quite different depending on the nonpolar part. In most cases, Lβ and Lα phases exist over wide composition ranges; certain additives induce transitions to other phases, which include cubic, reversed hexagonal liquid crystals and bicontinuous liquid phases. For a system containing additives, which induce a significant lowering of the Lβ–Lα transition, we identified the possibility of a triggered phase transition via dilution with water.

Amphiphilic Stilbene Derivatives Attenuate the Neurotoxicity of Soluble Aβ42 Oligomers by Controlling Their Interactions with Cell Membranes

<p>Misfolded proteins or polypeptides commonly observed in neurodegenerative diseases, including Alzheimer’s disease (AD), are promising drug targets for developing therapeutic agents. To target the amyloid-β (Aβ) plaques and oligomers, the hallmarks of AD, we have developed twelve amphiphilic small molecules with different hydrophobic and hydrophilic fragments. <i>In vitro</i> binding experiments (i.e., fluorescence saturation assays) demonstrated that these amphiphilic compounds show high binding affinity to both Aβ plaques and oligomers, and six of them exhibit even higher binding affinity toward Aβ oligomers. These amphiphilic compounds can also <a>label <i>ex vivo </i>Aβ species in the brain sections of transgenic AD mice, as shown by immunostaining with an Aβ antibody. </a>Molecular docking studies were performed to help understand the structure-affinity relationships. To our delight, four amphiphilic compounds can alleviate Cu²⁺-Aβ induced toxicity in mouse neuroblastoma N2a via cell toxicity assays. In addition, <a>confocal</a> fluorescence imaging studies provided evidence that compounds ZY-15-MT and ZY-15-OMe can disrupt <a>the interactions between Aβ oligomers and human neuroblastoma SH-SY5Y cell</a> membranes. Overall, these studies suggest that developing compounds with amphiphilic properties that target Aβ oligomers can be an effective strategy for small molecule AD therapeutics.</p>

Amphiphilic Stilbene Derivatives Attenuate the Neurotoxicity of Soluble Aβ42 Oligomers by Controlling Their Interactions with Cell Membranes

<p>Misfolded proteins or polypeptides commonly observed in neurodegenerative diseases, including Alzheimer’s disease (AD), are promising drug targets for developing therapeutic agents. To target the amyloid-β (Aβ) plaques and oligomers, the hallmarks of AD, we have developed twelve amphiphilic small molecules with different hydrophobic and hydrophilic fragments. <i>In vitro</i> binding experiments (i.e., fluorescence saturation assays) demonstrated that these amphiphilic compounds show high binding affinity to both Aβ plaques and oligomers, and six of them exhibit even higher binding affinity toward Aβ oligomers. These amphiphilic compounds can also <a>label <i>ex vivo </i>Aβ species in the brain sections of transgenic AD mice, as shown by immunostaining with an Aβ antibody. </a>Molecular docking studies were performed to help understand the structure-affinity relationships. To our delight, four amphiphilic compounds can alleviate Cu²⁺-Aβ induced toxicity in mouse neuroblastoma N2a via cell toxicity assays. In addition, <a>confocal</a> fluorescence imaging studies provided evidence that compounds ZY-15-MT and ZY-15-OMe can disrupt <a>the interactions between Aβ oligomers and human neuroblastoma SH-SY5Y cell</a> membranes. Overall, these studies suggest that developing compounds with amphiphilic properties that target Aβ oligomers can be an effective strategy for small molecule AD therapeutics.</p>

Features of Solubilizing Effect of Amphiphilic Compounds during Pulp Deresination

The necessity to improve the existing technology of pulp deresination, in particular, to reduce the surfactants consumption and decrease the environmental load, led to a combination of existing methods of resin removal with the use of enzymatic treatment. The basis of the pulp deresination mechanism by amphiphilic compounds is the solubilization of resinous substances. Thus, the establishment of the patterns of this process and its control predetermines the success of implementation of the selected technology. The features of solubilization of triolein and rosin in the lipase-based systems of individual nonionic surfactants, the enzyme, as well as their synergistic mixtures with the determination of solubilization capacities of micelles and the possible mechanism of solubilizate incorporation into them were studied using spectrophotometry, pH measurement and dynamic light scattering. It was found that synthamide-5 has a low deresination capability in spite of the high solubilization capacity of its micelles and the production of aggregates with a hydrodynamic radius up to 98 nm after diffusion of rosin into them. It is likely that compact micellar structures with a developed surface, which are implemented in mixed systems of amphiphilic compounds, including the presence of synthamide-5 in them, are more preferable for successful deresination of pulp semi-finished products. The addition of lipase leads to an increased solubilization capacity of mixed aggregates and an increase in the intensity of solubilizate molecules incorporation. Thus, depending on the nature of the amphiphilic compound, there is a different mechanism for solubilizate incorporation into micelles. Determination of the size of associates in mixed systems showed the absence of enzyme denaturation, which predicts the successful application of such cooperative systems for deresination of fiber semi-finished products. It is found that the solubilizing capability of the studied systems on resin modeling objects correlates with their deresination capability with respect to different fiber semi-finished products.

Thio-ether functionalized glycolipid amphiphilic compounds reveal a potent activator of SK3 channel with vasorelaxation effect

Sulfur analogues of Ohmline feature activation properties of SK3 ion channels. One compound exhibits promising endothelium dependent vasorelaxation.