Saponaria officinalis saponins as a factor increasing permeability of Candida yeasts' biomembrane.

Saponins are a large group of compounds, produced mostly by plants as a side product of their metabolic activity. These compounds have attracted much attention over the years mostly because of their surface activity and antibacterial, anti-inflammatory and antifungal properties. On the other hand, most of the hitherto research has concerned the action of saponins against microbial cells as a whole. Therefore, knowing the possible interaction of saponins with biomembrane, we decided to check in-vitro the influence of saponin-rich extract of Saponaria officinalis on spheroplasts of two Candida sp. The obtained results show that 10 mg L- 1 of extract increased the permeability of spheroplasts up to 21.76% relative to that of the control sample. Moreover, the evaluation of surface potential has revealed a decrease by almost 10 mV relative to that of the untreated samples. Such results suggest its direct correlation to integration of saponins into the biomembrane structure. The obtained results have proved the antifungal potential of saponins and their ability of permeabilization of cells. This proves the high potential of saponins use as additives to antifungal pharmaceutics, which is expected to lead to improvement of their action or reduction of required dosage.

Nanomechanical changes in probiotic bacteria under antibiotics exposure: Implications on Lactobacillus biofilm formation.

Recognition of the microbial cell's surface constituents' biophysical properties is an important research topic, allowing a better understanding of the cell's behaviour under different conditions. Atomic force microscopy (AFM) was employed in this study to analyse the basis of the nanomechanical changes in probiotic bacteria under nitrofurantoin, furazolidone, and nitrofurazone exposure. Recorded significant changes in the two Lactobacillus strains cells morphology, topography, and adhesion parameters resulted in the increase of the cells' longitude (up to 2.58 µm), profile height (by around 0.50 µm), and decrease in the adhesion force (up to 13.58 nN). Young's modulus and adhesion energy decreased within 96 h, however with no negative effect on the cells' morphology or loss of structural integrity. Observed modifications present the mode of action of the 5-nitrofuran derivative antibiotics on probiotic biofilm formation and suggest activation of the multilevel adaptation mechanisms to counteract unfavorable environments. A visual change in bacterial morphology such as an increased surface-to-volume ratio might be a link between molecular-level events and outcomes in individual cells and biofilms. This paper for the first time shows, that these antibiotics affect the properties of non-target microorganisms as lactobacilli, and might impair biofilm formation. However, the degree of such transformations depends on the delivered active substance.

Advances in electrospun materials for the adsorption and separation of environmental pollutants: A comprehensive review.

Despite a broad range of new techniques developed, adsorption methods remain one of the technologies of choice for the removal of contaminants. However, significant progress has also been made in these, which finds reflection in a new spectrum of adsorbents that can be used. This comprehensive review discusses properties, advantages, and perspectives on the use of custom-made electrospun adsorbents in the processes of heavy metals, agrochemicals, and microplastic contaminants removal from the environment. It presents the versatility and adaptability of materials that can be used as electrospun fibers matrix, also considering the mechanism and parameters of the sorption process carried out with them. The presented review proves, that due to the use of new, custom-made sorbents, such as electrospun materials, the adsorption processes still possess great application potential and development opportunities to provide an attractive and effective alternative to other remediation techniques.

Thermodynamic Consideration of the Solid Saponin Extract Drop-Air System.

The aim of this research was to elucidate the surface active properties of Saponaria officinalis (soapwort) extract containing the plant surfactants saponins. To this end, the advancing contact angle (θ) of water, formamide and diiodomethane on the glass, as well as θ of the aqueous solution of S. officinalis extract fractions on PTFE, PMMA and glass, were studied. Based on the obtained results, the wetting behaviour of saponins was considered with regard to the surface tension components and parameters of the solutions and solids. The investigations also involved the description of the θ isotherms, the dependences between the cosine of contact angle and/or the adhesion of the solution to the solid surfaces and solution surface tension, as well as the critical surface tension of PTFE, PMMA and glass wetting. These dependences were studied based on the saponin adsorption at the different interfaces, which was deduced from the dependence between the adhesion and surface tension of the solution, as well as using the Gibbs and Frumkin isotherm equations. This proved that the saponins are poor wetting agents and that the contact angle isotherm can be described by the exponential function of the second order as well as the Szyszkowski equation, but only for PTFE.

Co-interaction of nitrofuran antibiotics and the saponin-rich extract on gram-negative bacteria and colon epithelial cells.

Large-scale use of nitrofurans is associated with a number of risks related to a growing resistance to these compounds and the toxic effects following from their increasing presence in wastewater and the environment. The aim of the study was to investigate an impact of natural surfactant, saponins from Sapindus mukorossi, on antimicrobial properties of nitrofuran antibiotics. Measurements of bacterial metabolic activity indicated a synergistic bactericidal effect in samples with nitrofurantoin or furazolidone, to which saponins were added. Their addition led to more than 50% greater reduction in viable cells than in the samples without saponins. On the other hand, no toxic effect against human colon epithelial cell was observed. It was found that exposure to antibiotics and surfactants caused the cell membranes to be dominated by branched fatty acids. Moreover, the presence of saponins reduced the hydrophobicity of the cell surface making them almost completely hydrophilic. The results have confirmed a high affinity of saponins to the cells of Pseudomonas strains. Their beneficial synergistic effect on the action of antibiotics from the nitrofuran group was also demonstrated. This result opens promising prospects for the use of saponins from S. mukorossi as an adjuvant to reduce the emission of antibiotics into the environment.

3D printed polylactide scaffolding for laccase immobilization to improve enzyme stability and estrogen removal from wastewater.

This study reports a biocatalytic system of immobilized laccase and 3D printed open-structure biopolymer scaffoldings. The scaffoldings were computer-designed and 3D printed using polylactide (PLA) filament. The immobilization of laccase onto the 3D printed PLA scaffolds were optimized with regard to pH, enzyme concentration, and immobilization time. Laccase immobilization resulted in a small reduction in reactivity (in terms of Michaelis constant and maximum reaction rate) but led to significant improvement in chemical and thermal stability. After 20 days of storage, the immobilized and free laccase showed 80% and 35% retention of the initial enzymatic activity, respectively. The immobilized laccase on 3D printed PLA scaffolds achieved 10% improvement in the removal of estrogens from real wastewater as compared to free laccase and showed the significant reusability potential. Results here are promising but also highlight the need for further study to improve enzymatic activity and reusability.

Multi-faceted analysis of bacterial transformation of nitrofurantoin.

Excessive presence of antibiotics and their residues can be dangerous to the natural environment. To reduce this negative effect, efficient strategies to remove them from the ecosystem are required. This study aimed to explore the potential of bacterial strains to degrade nitrofurantoin (NFT). Single strains isolated from contaminated areas, namely Stenotrophomonas acidaminiphila N0B, Pseudomonas indoloxydans WB, and Serratia marcescens ODW152 were employed in this study. Degradation efficiency and dynamic changes within the cells during NFT biodegradation were investigated. For this purpose, atomic force microscopy, flow cytometry, zeta potential, and particle size distribution measurements were applied. Serratia marcescens ODW152 showed the highest performance in removal of NFT (96 % in 28 days). The AFM images revealed modifications of cell shape and surface structure induced by NFT. Zeta potential showed significant variations during biodegradation. Cultures exposed to NFT had a broader size distribution than the control cultures due to increased cells agglomeration or aggregation. 1-Aminohydantoin and semicarbazide were detected as nitrofurantoin biotransformation products. They showed increased cytotoxicity toward bacteria as determined by spectroscopy and flow cytometry. Results of this study suggest that nitrofurantoin biodegradation leads to formation of stable transformation products that significantly affect the physiology and structure of bacterial cells.

Study of Interactions between Saponin Biosurfactant and Model Biological Membranes: Phospholipid Monolayers and Liposomes.

The aim of this study was to determine the effect of saponins-rich plant extract on two model biological membranes: phospholipid monolayers and liposomes. The Langmuir monolayer technique was used to study the interactions of model phospholipid membranes with saponins. The π-A isotherms were determined for DPPE (1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine) monolayer with the addition of various concentrations of licorice saponins extracts and subjected to qualitative as well as quantitative analysis. Additionally, relaxation studies of the obtained monolayers were carried out and morphological changes were examined using Brewster angle microscopy. Moreover, changes in the structure of phospholipid vesicles treated with solutions of saponins-rich plant extracts were assessed using the FTIR technique. The size and zeta potential of the liposomes were estimated based on DLS methods. The obtained results indicated that the saponins interact with the phospholipid membrane formed by DPPE molecules and that the stability of the mixed DPPE/saponins monolayer strongly depends on the presence of impurities in saponins. Furthermore, it was found that the plant extract rich in saponins biosurfactant interacts mainly with the hydrophilic part of liposomes.

Potential negative effect of long-term exposure to nitrofurans on bacteria isolated from wastewater.

Nitrofurans are broad-spectrum bactericidal agents used in a large quantity for veterinary and human therapy. This study reports the long-term impact of two nitrofuran representatives, nitrofurantoin (NFT) and furaltadone (FTD) on the bacterial strains Sphingobacterium siyangense FTD2, Achromobacter pulmonis NFZ2, and Stenotrophomonas maltophilia FZD2, isolated from a full-scale wastewater treatment plant. Bacterial whole genome sequencing was used for preliminary strains characterization. The metabolomic, electrochemical, and culture methods were applied to understand changes in the bacterial strains after 12-month exposure to nitrofurans. The most significantly altered metabolic pathways were observed in amino acid and sugar metabolism, and aminoacyl-tRNA biosynthesis. Disrupted protein biosynthesis was measured in all strains treated with antibiotics. Prolonged exposure to NFT and FTD also triggered mutagenic effects, affected metabolic activity, and facilitated oxidative stress within the cells. Nitrofuran-induced oxidative stress was evidenced from an elevated activity of catalase and glutathione S-transferases. NFT and FTD elicited similar but not identical responses in all analyzed strains. The results obtained in this study provide new insights into the potential risks of the prolonged presence of antimicrobial compounds in the environment and contribute to a better understanding of the possible impacts of nitrofuran antibiotics on the bacterial cells.

Dynamics of microbial communities during biotransformation of nitrofurantoin.

The purpose of this research was to investigate the biodegradation of nitrofurantoin (NFT), a typical nitrofuran antibiotic of potential carcinogenic properties, by two microbial communities derived from distinct environmental niches - mountain stream (NW) and seaport water (SS). The collected environmental samples represent the reserve of the protected area with no human intervention and the contaminated area that concentrates intense human activities. The structure, composition, and diversity of the communities were analyzed at three timepoints during NFT biodegradation. Comamonadaceae (43.2%) and Pseudomonadaceae (19.6%) were the most abundant families in the initial NW sample. The top families in the initial SS sample included Aeromonadaceae (31.4%) and Vibrionaceae (25.3%). The proportion of the most abundant families in both consortia was remarkably reduced in all samples treated with NFT. The biodiversity significantly increased in both consortia treated with NFT suggesting that NFT significantly alters community structure in the aquatic systems. In this study, NFT removal efficiency and transformation products were also studied. The biodegradation rate decreased with the increasing initial NFT concentration. Biodegradation followed similar pathways for both consortia and led to the formation of transformation products: 1-aminohydantoin, semicarbazide (SEM), and hydrazine (HYD). SEM and HYD were detected for the first time as NFT biotransformation products. This study demonstrates that the structure of the microbial community may be directly correlated with the presence of NFT. Enchanced biodiversity of the microbial community does not have to be correlated with increase in functional capacity, such as the ability to biodegradation because higher biodiversity corresponded to lower biodegradation. Our findings provide new insights into the effect of NFT contamination on aquatic microbiomes. The study also increases our understanding of the environmental impact of nitrofuran residues and their biodegradation.

The Bioactivity and Physicochemical Properties of Emulsions Based on Tamanu, Moringa, and Inca Inchi Oils.

With increasing bacterial resistance to antibiotics, novel strategies for protection against microbial infections are crucial. Emulsions enhance the solubility of natural antibacterial oils and their uptake, making them promising drug delivery systems. However, it is important to find the right emulsifier to ensure that the oil has the right dispersion and does not adversely affect its antibacterial properties. Hence, this study investigated emulsions created from three vegetable oils: moringa oil from Moringa oleifera seeds, inca inchi oil from Plukenetia volubilis seeds, and tamanu oil from the Calophyllum inophyllum fruit. Emulsions were formed using two natural emulsifiers, lecithin and casein, at concentrations of 2.5%, 5%, and 10% (w/w). The study assessed the oil and emulsions' characteristics, including the zeta potential, creaming index, and particle size distribution. The antimicrobial properties of these oils and the most stable emulsions were examined. Gas chromatography was used to analyze the oil compositions. The potential antimicrobial properties of emulsions formulated with natural oils was proved. Particularly noteworthy were emulsions containing a 2.5% inca inchi or tamanu oil, stabilized with casein. The particle size ranged between 100 nm and 900 nm with the average size 300 nm. These emulsions also showed antibacterial activity against selected strains, and the strongest effect was observed for the system with inca inchi oil, which reduced S. epidermidis bacterial activity by more than 60%. Therefore, it can be expected that the completed research will allow the development of antibacterial systems based on inca inchi or tamanu oils for use in the food industry.

Factors Influencing the Bioavailability of Organic Molecules to Bacterial Cells-A Mini-Review.

The bioavailability of organic compounds to bacterial cells is crucial for their vital activities. This includes both compounds that are desirable to the cells (e.g., sources of energy, carbon, nitrogen, and other nutrients) and undesirable compounds that are toxic to the cells. For this reason, bioavailability is an issue of great importance in many areas of human activity that are related to bacteria, e.g., biotechnological production, bioremediation of organic pollutants, and the use of antibiotics. This article proposes a classification of factors determining bioavailability, dividing them into factors at the physicochemical level (i.e., those related to the solubility of a chemical compound and its transport in aqueous solution) and factors at the microbiological level (i.e., those related to adsorption on the cell surface and those related to transport into the cell). Awareness of the importance of and the mechanisms governing each of the factors described allows their use to change bioavailability in the desired direction.

Enzymatic membrane reactor in xylose bioconversion with simultaneous cofactor regeneration.

In this study, we present the concept of co-immobilization of xylose dehydrogenase and alcohol dehydrogenase from Saccharomyces cerevisiae on an XN45 nanofiltration membrane for application in the process of xylose bioconversion to xylonic acid with simultaneous cofactor regeneration and membrane separation of reaction products. During the research, the effectiveness of the co-immobilization of enzymes was confirmed, and changes in the properties of the membrane after the processes were determined. Using the obtained biocatalytic system it was possible to obtain 99% xylonic acid production efficiency under optimal conditions, which were 5 mM xylose, 5 mM formaldehyde, ratio of NAD+:NADH 1:1, and 60 min of reaction. Additionally, the co-immobilization of enzymes made it possible to improve stability of the co-immobilized enzymes and to carry out xylose conversion in six consecutive cycles and after 7 days of storage at 4 °C with over 90% efficiency. The presented data confirm the effectiveness of the co-immobilization, improvement of the stability and reusability of the biocatalysts, and show that the obtained enzymatic system is promising for use in xylose bioconversion and simultaneous regeneration of nicotinamide cofactor.

Biocatalytic System Made of 3D Chitin, Silica Nanopowder and Horseradish Peroxidase for the Removal of 17α-Ethinylestradiol: Determination of Process Efficiency and Degradation Mechanism.

The occurrence of 17α-ethinylestradiol (EE2) in the environment and its removal have drawn special attention from the scientific community in recent years, due to its hazardous effects on human and wildlife around the world. Therefore, the aim of this study was to produce an efficient enzymatic system for the removal of EE2 from aqueous solutions. For the first time, commercial silica nanopowder and 3D fibrous chitinous scaffolds from Aplysina fistularis marine sponge were used as supports for horseradish peroxidase (HRP) immobilization. The effect of several process parameters onto the removal mechanism of EE2 by enzymatic conversion and adsorption of EE2 were investigated here, including system type, pH, temperature and concentrations of H2O2 and EE2. It was possible to fully remove EE2 from aqueous solutions using system SiO2(HRP)-chitin(HRP) over a wide investigated pH range (5-9) and temperature ranges (4-45 °C). Moreover, the most suitable process conditions have been determined at pH 7, temperature 25 °C and H2O2 and EE2 concentrations equaling 2 mM and 1 mg/L, respectively. As determined, it was possible to reuse the nanoSiO2(HRP)-chitin(HRP) system to obtain even 55% EE2 degradation efficiency after five consecutive catalytic cycles.

Azole fungicides: (Bio)degradation, transformation products and toxicity elucidation.

The increasing consumption of azole antifungal agents leads to their uncontrolled release into the environment. Therefore, it is crucial to remove their residues from natural ecosystems. This study aimed to examine the biological and chemical degradation of four typical azole fungicides: fluconazole (Fc), clotrimazole (Cl), climbazole (Cb), and epoxiconazole (Ep). The biodegradation was investigated using activated sludge and two novel Gram-negative bacterial strains. The chemical degradation experiments aimed to assess the efficiency of fungicides removal through UV treatment, the Fenton reaction, and a combination of these methods. Transformation products of Cb, Ep, and Cl photocatalytic removal were identified by mass spectrometry. In addition, the AlamarBlue® Assay and the MTT Assay allowed careful evaluation of the toxicity of azole derivatives and their transformation products towards newly isolated strains, Stenotrophomonas maltophilia AsPCl2.3 and Pseudomonas monteilii LB2. Among all azole fungicides, Cb was the most susceptible to biological removal while Fc, Ep, and Cl were basically resistant to biodegradation. Cl and Ep showed a significant biosorption on the activated sludge. Under optimized photolysis conditions, the removal efficiency of Cl, Cb, and Ep was significantly higher than that of biodegradation. The Fenton reaction supported by the UV-irradiation offered the best results of fungicides elimination. After 1 min of the experiment, Cl was almost completely removed while Cb and Ep removal rates reached an average of 60%. The proposed main degradation route of azole fungicides during UV-irradiation includes halogen atoms substitution by hydroxyl moieties. The final degradation product was imidazole or triazole. Azole fungicides and their transformation products differently affected the metabolic activity of Gram-negative bacteria. Cl and Cb intermediates showed lower toxicity than parent compounds. The findings help better understand the environmental impact of azole fungicides, their degradation, and toxicity. They also stress the need for reducing their uncontrolled release to the environment.

Langmuir Monolayer Techniques for the Investigation of Model Bacterial Membranes and Antibiotic Biodegradation Mechanisms.

The amounts of antibiotics of anthropogenic origin released and accumulated in the environment are known to have a negative impact on local communities of microorganisms, which leads to disturbances in the course of the biodegradation process and to growing antimicrobial resistance. This mini-review covers up-to-date information regarding problems related to the omnipresence of antibiotics and their consequences for the world of bacteria. In order to understand the interaction of antibiotics with bacterial membranes, it is necessary to explain their interaction mechanism at the molecular level. Such molecular-level interactions can be probed with Langmuir monolayers representing the cell membrane. This mini-review describes monolayer experiments undertaken to investigate the impact of selected antibiotics on components of biomembranes, with particular emphasis on the role and content of individual phospholipids and lipopolysaccharides (LPS). It is shown that the Langmuir technique may provide information about the interactions between antibiotics and lipids at the mixed film surface (π-A isotherm) and about the penetration of the active substances into the phospholipid monolayer model membranes (relaxation of the monolayer). Effects induced by antibiotics on the bacterial membrane may be correlated with their bactericidal activity, which may be vital for the selection of appropriate bacterial consortia that would ensure a high degradation efficiency of pharmaceuticals in the environment.

New Biocomposite Electrospun Fiber/Alginate Hydrogel for Probiotic Bacteria Immobilization.

Biotechnological use of probiotic microorganisms involves providing them with appropriate conditions for growth, but also protection against environmental changes caused by an exchange of the medium, isolation of metabolites, etc. Therefore, the research on effective immobilization of probiotic microorganisms should be focused in this direction. The present study aimed to evaluate the effectiveness of an innovative hybrid immobilization system based on electrospun nanofibers and alginate hydrogel. The analyses carried out included the study of properties of the initial components, the evaluation of the degree and durability of cell immobilization in the final material, and their survival under stress conditions. Effective binding of microorganisms to the hydrogel and nanofibers was confirmed, and the collected results proved that the proposed biocomposite is an efficient method of cell protection. In addition, it was shown that immobilization on electrospun nanofibers leads to the preservation of the highest cell activity and the least cell growth restriction as compared to free or lyophilized cells only. The completed research opens new perspectives for the effective immobilization of microorganisms of significant economic importance.

Significance of the presence of antibiotics on the microbial consortium in wastewater - The case of nitrofurantoin and furazolidone.

Antibiotics in wastewater leads to migration of pollutants and disrupts natural processes of mineralization of organic matter. In order to understand the mechanism of this, research was undertaken on the influence of nitrofurantoin (NFT) and furazolidone (FZD), on the behaviour of a consortium of microorganisms present in a model wastewater in a bioreactor. Our study confirmed biodegradation of the antibiotics by the microbial consortium, with the degradation efficiency within 10 days of 65% for FZD, but only 20% for NFT. The kinetic study proved that the presence of analysed antibiotics had no adverse effect on the microbes, but the consortium behaviour differ significantly with the NFT reducing the consumption of organic carbon in wastewater and increasing the production of extracellular biopolymeric and volatile organic compounds, and the FZD reducing assimilation of other carbon sources to a less extent, at the expense of cellular focus on biodegradation of this antibiotic.

Nitrofurazone Removal from Water Enhanced by Coupling Photocatalysis and Biodegradation.

(1) Background: Environmental contamination with antibiotics is particularly serious because the usual methods used in wastewater treatment plants turn out to be insufficient or ineffective. An interesting idea is to support natural biodegradation processes with physicochemical methods as well as with bioaugmentation with efficient microbial degraders. Hence, the aim of our study is evaluation of the effectiveness of different methods of nitrofurazone (NFZ) degradation: photolysis and photodegradation in the presence of two photocatalysts, the commercial TiO2-P25 and a self-obtained Fe3O4@SiO2/TiO2 magnetic photocatalyst. (2) Methods: The chemical nature of the photocatalysis products was investigated using a spectrometric method, and then, they were subjected to biodegradation using the strain Achromobacter xylosoxidans NFZ2. Additionally, the effects of the photodegradation products on bacterial cell surface properties and membranes were studied. (3) Results: Photocatalysis with TiO2-P25 allowed reduction of NFZ by over 90%, demonstrating that this method is twice as effective as photolysis alone. Moreover, the bacterial strain used proved to be effective in the removal of NFZ, as well as its intermediates. (4) Conclusions: The results indicated that photocatalysis alone or coupled with biodegradation with the strain A. xylosoxidans NFZ2 leads to efficient degradation and almost complete mineralization of NFZ.

Evaluation of surface active and antimicrobial properties of alkyl D-lyxosides and alkyl L-rhamnosides as green surfactants.

The use of carbohydrates, as a part of surface-active compounds, has been studied due to their biodegradability and nontoxic profile. A series of alkyl glycosides containing d-lyxose and l-rhamnose with alkyl chains of 8-12 carbon atoms were investigated. The effects of structural variations on their physico-chemical and biological properties have been evaluated for a detailed understanding of their properties. Alkyl glycosides were tested on their toxicity against bacterial cells of the genus Pseudomonas (MTT assay), microbiological adhesion to hydrocarbons (MATH assay), cell surface hydrophobicity (Congo red assay), cell membrane permeability (crystal violet assay), and bacterial biofilm formation. Furthermore, their antifungal activity against two pathogenic microorganisms Candida albicans and Aspergillus niger was investigated using the disc diffusion method. Toxicological studies revealed that compounds could reduce the metabolic activity of bacterial cells only moderately but they increased the hydrophobicity of cell surface in Pseudomonas strains. In addition, alkyl glycosides changed the permeability of the cell membranes to the level of 30-40% for this strain. The compounds with an even number of carbon atoms in their alkyl chain promoted stronger bacterial biofilm formation on the glass surface. All studied derivatives demonstrated very strong antifungal activity against fungus A. niger but very small effect against C. albicans. Overall, the results showed that long-chain alkyl glycosides could be considered as inexpensive, biocompatible, nontoxic agents, and serve for the surface design to avoid bacterial adhesion as an alternative solution to antibiotic treatment.