Salt Medium Research Articles

Development of an efficient expression system for human chaperone BiP in Pichia pastoris: production optimization and functional validation

BackgroundHuman BiP, or GRP78, is a molecular chaperone mainly found in the endoplasmic reticulum (ER). However, a growing amount of data also associates BiP with many distinct functions in subcellular locations outside the ER. Notably, several diseases have been BiP-related, so the protein could potentially be used for therapeutic purposes. This study aimed to optimize a high cell-density fermentation process for the production of recombinant human BiP (rhBiP) in yeast Pichia pastoris in a mineral medium.ResultsP. pastoris cells successfully synthesized and secreted full-length rhBiP protein in a complex growth medium. However, secreted rhBiP titer was considerably lower when P. pastoris was cultivated in a defined mineral basal salt medium (BSM). During rhBiP synthesis optimization in shake flasks, it was found that the addition of reducing compounds (DTT or TCEP) to mineral BSM medium is essential for high-yield rhBiP production. Furthermore, rhBiP secretion in the BSM medium was significantly increased by feeding yeast with an additional carbon source. The addition of 2 mM DTT and 0.5-1.0% of glucose/glycerol to the BSM medium increased rhBiP titer ~ 8 times in the shake flasks. Glucose/methanol mixture feeding with added 2 mM DTT before induction was applied in high-density P. pastoris fermentation in bioreactor. Oxygen-limited fermentation strategy allowed to achieve ~ 70 mg/L rhBiP in BSM medium. Hydrophobic interaction and anion exchange chromatography were used for rhBiP protein purification. Approximately 45 mg rhBiP was purified from 1 L growth medium, and according to SDS-PAGE, ~ 90% purity was reached. According to data presented in this study, rhBiP protein derived from P. pastoris is a full-length polypeptide that has ATPase activity. In addition, we show that P. pastoris-derived rhBiP effectively inhibits neurodegenerative disease-related amyloid beta 1–42 (Aβ42) peptide and alpha-synuclein (α-Syn) protein aggregation in vitro.ConclusionsA scalable bioprocess to produce rhBiP in P. pastoris was developed, providing a high yield of biologically active protein in a chemically defined mineral medium. It opens a source of rhBiP to accelerate further therapeutic applications of this important protein.

Screening and characterization of PHA producing bacteria from sewage water identifying Bacillus paranthracis RSKS-3 for bioplastic production

Polyhydroxyalkanoate (PHA) as bioplastic is considered a replacement for conventional plastic due to its more beneficial properties. The ability of PHA to biodegrade in a shorter period is a major advantage. Different sewage water samples were collected from the Budha Nala near the Maheru regions of Punjab. PHA-producing bacteria were isolated using minimal salt media supplemented with Nile blue. Further screening was carried out using Sudan Black B stain and Nile red stain. The positive isolates were characterized for gram reaction, motility, and biochemical tests. The individual isolates were later screened for maximum PHA accumulation using minimal salt supplemented with glucose. The extracted PHA was characterized using FTIR, XRD, SEM, UV spectroscopy, NMR, and TGA. Twenty-six different PHA-producing bacteria were isolated on minimal salt media supplemented with Nile blue. Upon Sudan Black B stain and Nile red stain, nineteen isolates showed black granules and orange fluorescence bodies under 100X magnification that confirmed polyhydroxyalkanoates. The biochemical tests partially characterized isolates belonging to the Bacillus genus. All the isolates produced PHA in granular form, however, isolate P-3 showed maximum production of 0.068 g/L. The extracted PHA was characterized using FTIR and XRD for its chemical and crystallinity studies and the UV spectroscopy confirmed the extracted PHA by analyzing absorption spectra at 235 nm of standard crotonic acid and sulfuric acid conversion of PHA to crotonic acid. The isolated P-3, Bacillus paranthracis RSKS-3 is the first reported bacterium to produce polyhydroxyalkanoates. Further studies is necessary to optimize the production efficiency of the bacterium for maximum PHA yield.

One-Pot Synthesis of Fluorescent 3-Amino-2-arylquinolin-4(1H)-ones from Isatoic Anhydride and 1-(2-Oxo-2-arylethyl)pyridinium Salts

A one-pot method was proposed for the synthesis of 3-amino-2-arylquinolin-4(1H)-ones based on intermolecular cyclocondensation of isatoic anhydride and 1-(2-oxo-2-arylethyl)pyridinium salts in a basic medium followed by decomposition of pyridinium to amine by the action of hydrazine hydrate. Solutions of all the obtained amines emit in the blue-green region of the visible spectrum with a fluorescence quantum yield of up to 0.59 when irradiated with ultraviolet or violet light.

Potential of newly isolated strain Pseudomonas aeruginosa MC-1/23 for the bioremediation of soil contaminated with selected non-steroidal anti-inflammatory drugs.

The widespread usage of non-steroidal anti-inflammatory drugs (NSAIDs) has resulted in their significant accumulation in the environment, necessitating the development of effective methods for their removal. This study primarily isolated a bacterial strain capable of degrading specific NSAIDs and evaluated its potential for eliminating these drugs from contaminated soil through bioaugmentation. The objectives were achieved by assessing the degradation rates of ibuprofen (IBF), diclofenac (DCF), and naproxen (NPX) in liquid media and soil samples inoculated with a newly identified strain, Pseudomonas aeruginosa MC-1/23. In addition, the effect of natural soil microflora and abiotic conditions on the breakdown of the tested NSAIDs was examined. The findings revealed that strain MC-1/23 could metabolize these compounds in a mineral salt medium, utilizing them as carbon and energy sources, suggesting metabolic degradation. When nonsterile soil was augmented with the P. aeruginosa MC-1/23 strain, the degradation rates of the drugs significantly improved, as evidenced by reductions in t1/2 values by 5.3-, 1.4-, and 5.8-fold for IBF, DCF, and NPX, respectively, compared with soil containing only natural microflora. These results confirm that the introduced strain enhances the catabolic potential of existing microflora. Thus, the strain’s degradation and bioremediation capabilities offer valuable applications for remediating NSAID-contaminated soils.

Effects of biogenic and commercially available iron-oxide nanoparticles on algal and bacterial growth in freshwater and marine water.

We investigated the potential toxic effects of iron oxide magnetic nanoparticles (IOMNPs) of varied size, synthesized through biological and chemical methods on freshwater and marine microalgae and bacterial species. The study provides insights into pollution and ecological impacts of NPs. IOMNPs of two sizes, 20-50nm (quasi-spherical) synthesized using a cell-free fungal extract (biogenic method), and 104nm (spherical) obtained from a commercial source (chemical method), were tested for aggregation, bioavailability, and toxicity at multiple concentrations (12.5, 25, 50, 100, and 125µg mL-1). Microalgal growth media (Bold's basal media and sea salt media [SSM]) was used for aggregation analysis of IOMNPs using dynamic light scattering (DLS) technique. DLS analysis showed similar aggregation patterns for both type of IOMNPs, with relatively larger aggregate formation in SSM. Toxicity assessments showed that biogenic IOMNPs of smaller size 20-50nm were non-toxic, while commercial IOMNPs of large size (104nm) significantly reduced bacterial cell density and microalgal lipid and carotenoid content at higher concentrations. Further, transmission electron microscopy and X-ray fluorescence analysis confirmed IOMNP uptake by microalgae. TEM images showed more pronounced structural damage caused by the uptake of commercial IOMNPs. Our findings provide crucial insights into the differential impacts of IOMNPs based on their size and synthesis methods on key aquatic microorganisms and their potential to mitigate issues related to NP pollution.

Selective and Sensitive Detection of 2,4,6 Trinitrophenol (TNP) by Imidazolium Salt in Aqueous Medium

Selective and Sensitive Detection of 2,4,6 Trinitrophenol (TNP) by Imidazolium Salt in Aqueous Medium

Isolation, Identification, and Characterization of Putative Dye-Degrading Bacteria from Polluted Soil: Bioremediation Investigations

The residual dye within the soil from the synthetic dye manufacturing and fabric industries is a global state of affairs. The discharge consists of an excessive content of pigments and other components, creating complicated structures. It leads to damage to the soil structure and its fertility. Amid existing amputation methods, microbial remediation takes significant consideration owing to its subordinate charge, sophisticated proficiency, and fewer influences on the milieu. The current study was premeditated for the seclusion and portrayal of azo dye- dye-decolorizing bacteria, which is a criterion for emerging a microorganism-facilitated treatment of adulterating dyes. In this present investigation, twenty sorts of bacteria that were talented to decolorize seven kinds of azo dyes (Crystal Violet, Methylene Blue, Safranine, Congo Red, Methyl Orange, Malachite Green, and Carbol Fuchsin) were isolated from dye-polluted soil from the dying industry near the railway station; in Calicut. Based on 16S rDNA scrutiny, the most resourceful decolourizing bacteria for these azo dyes was identified as Priestia megaterium strain NRBC 15308. After characterization, Priestia megaterium was found to be optimally nurtured at 35°C, on a pH of 7, with a 1.5% glucose concentration in a minimal salt medium. 100% decolorization of a 6% dye solution was found at optimal conditions by Priestia megaterium. Priestia megaterium can decolorize cotton and gauze suspended in the dye solution in 24 hours. Bioremediation studies with the isolate proved that the inhibition effect of the dye solution on seed germination could be removed by the application of Prestia megaterium. The isolation of Priestia megaterium strain NRBC 15308 as a dye-degrading bacterium holds immense promise for remediating dye-contaminated soil.

Mechanisms Underlying Phase Transition and Regulation of Tantalum Powder Properties During Magnesium Thermal Reduction of Ta2O5 in a Molten Salt Medium.

Magnesium reduction of Ta2O5 (tantalum pentoxide) is a metallurgical process widely used to extract metallic tantalum powder from its oxide form using magnesium as a reducing agent in a molten salt medium. This study explores the mechanisms and patterns of phase transformation during the magnesium reduction of Ta2O5 in a molten salt medium, focusing on the influence of temperature and time on the physical and chemical properties of the resulting tantalum powder. The results reveal that under various reaction conditions in a molten salt medium, the magnesium reduction of Ta2O5 follows four distinct pathways: Ta2O5 → Ta, Ta2O5 → MgTa2O6 → Ta, Ta2O5 → MgTa2O6 → Mg4Ta2O9 → Ta, and Ta2O5 → Mg4Ta2O9 → Ta. Each pathway significantly affects the physical and chemical properties of the resulting tantalum powder. Using a uniform mixing method, the reaction proceeds directly from Ta2O5 to Ta powder in a single step. As the reaction temperature increases from 600 °C to 900 °C, the average particle size of the tantalum powder enlarges from 30 nm to 150 nm, with the product phase transitioning from a mixture of Ta and Ta2O to a single Ta phase. Additionally, prolonged holding time improves the uniformity of the tantalum powder's particle distribution. This study accomplishes directional control over the phase transformation and the properties of tantalum powder during the reduction process, thus offering valuable guidance for the preparation of high-performance tantalum powder.

Corrosion inhibition of bis-isoQuinolinium salts derivatives for mild steel A283 Grade C in sulfuric media: an experimental and theoretical investigation

This work examines the efficiency of four bis-isoQuinolinium compounds in preventing the corrosion of A283 Grade C steel in a 0.5 M H2SO4 solution. The performance of these corrosion inhibitors was examined at various concentrations using weight loss, electrochemical impedance spectroscopy, and potentiodynamic polarization. Using gravimetric weight loss, the efficiency (IE%) reached a high value of 97.32, 98.14, 97.94, and 98.14% when the concentration reached 5 mM of bis-isoQuinolinium salts EtiQuiBr, PriQuiBr, BuiQuiBr, and PniQuiBr, respectively. According to the different investigations, the bis-isoQuinolinium salts are mixed-type inhibitors with slight predominance of cathodic inhibition. The adsorption of all studied inhibitors on the metal surface of A283 Grade C mild steel followed the Langmuir adsorption isotherm and the inhibition efficiencies decreased with temperature. The thermodynamic parameters, such as Ea, Kads, and ΔG°ads were determined. The negative values of ΔG°ads suggested a favorable adsorption of all inhibitors on steel surface. The order of IE determined from experimental measurements is: EtiQuiBr < PriQuiBr < BuiQuiBr < PniQuiBr. Furthermore, microscopic surface analyses, such as SEM and AFM were used to characterize the surface morphology of the steel specimens. Moreover, the Density Functional Theory (DFT) calculations were performed to correlate the electronic molecular structure of the studied inhibitors with their inhibition efficiency. The tested compounds can be effectively used as corrosion inhibitors for steel in sulfuric acid and the findings of this work shed more light on the corrosion inhibition of steel by ammonium salts in acidic medium.

Morpho-physiological, Biochemical, and Transcript Analysis Revealed Differential Behavior of Chickpea Genotypes Towards Salinity.

Till now, limited information was available on salt tolerance chickpea genotypes. Therefore, in comparison to CSG 8962 (check for salinity tolerance), an experiment on nine chickpea genotypes with different background (BG 1103, DCP 92-3, S7, ICCV 10, BG 256, KWR 108, JG 16, K 850, and ICC 4463) was conducted under medium salt stress of ECiw ~6 dS m-1and high salt stress of 9 dS m-1 to evaluate their salt tolerance potential. Different morphological, physiological, biochemical, and molecular traits were studied to characterize these genotypes. It was also noted that growth of all the genotypes was affected by salinity, but more reduction was shown by the genotypes BG 256, DCP 92-3, and ICC 4463. Irrigation water loaded with salts disrupted the water relations as displayed by the reducing values of RWC, waterpotential, and osmotic potential. Chlorophyll content, when compared with control, reduced in the range of 7.06 to 28.93% at moderate salinity level (ECiw ~6 dS m-1) and 23.71 to 55.83% at higher salinity level (ECiw ~9 dS m-1). S7, ICCV 10, KWR 108, and CSG 8962 (salt-tolerant check) maintained optimum gas exchange traits, i.e., photosynthetic rate, stomatal conductance, and transpiration rate with increasing salinity and osmoregulatory compounds, imino acid proline, and total soluble sugars were also higher in these genotypes. Na+/K+ ratio at control was 0.084 and it enhanced with increasing salinity and noted mean genotypic values of 0.399 and 0.758 at moderate and higher salinity levels, respectively. Antioxidative defense mechanism was quite active in the genotypes (S7, ICCV 10, KWR 108, and check CSG 8962) because higher values of antioxidative enzymes and low increment in the content of hydrogen peroxide and malondialdehyde were noted in these genotypes. Based on the results, genotypes with salinity contrasting response (KWR 108 as tolerant and ICC 4463 as sensitive) were selected, and gene expression studies were conducted along with CSG 8962 (the check). It was found that KWR 108 showed higher expression of Δ1-pyrroline-5-carboxylate synthetase (P5CS), pyrroline-5-carboxylate reductase (P5CR), Na+/H+ antiporter (NHX1), and sodium transporter HKT1 and downregulation of proline dehydrogenase gene than the genotype CSG 8962 (salt-tolerant check). So, it was concluded that genotypes, i.e., S7, KWR 108, and ICCV 10, maintained higher physiological and biochemical efficiency in terms of lower ψw, ψs, and membrane stability, higher RWC, photosynthetic rate, and osmolyte accumulation as well as antioxidative enzyme activities in comparison to the salt-tolerant check used in the study. Further, these results were validated through gene expression studies which revealed similar results that categorized these genotypes to be salt tolerant.

ASSESSING THE BIOTECHNOLOGICAL INFLUENCE OF ENVIRONMENTAL STRESSORS ON SYNERGISTIC MICROBIAL PLASTIC WASTE DEGRADATION

Background: Plastic pollution is a critical environmental issue due to the persistence of synthetic polymers in natural ecosystems. Conventional waste management approaches are inefficient in addressing this challenge, necessitating sustainable alternatives. Microbial degradation has emerged as a promising biotechnological solution, as specific bacterial and fungal strains possess enzymatic capabilities to degrade plastics. However, the efficiency of microbial plastic biodegradation is highly dependent on environmental factors, including temperature, pH, and oxygen availability. This study evaluates how these stressors influence the degradation of polyethylene (PE) and polyethylene terephthalate (PET) to optimize microbial plastic waste management strategies. Objective: This study aimed to assess the impact of temperature, pH, and oxygen availability on microbial plastic degradation efficiency and to determine the optimal environmental conditions that enhance biodegradation rates. Methods: Following ethical approval (ERC144/23) from Punjab University Lahore, plastic-degrading microbial strains were isolated from landfill sites and aquatic environments. These isolates were cultured in a controlled laboratory setting using minimal salt medium supplemented with PE and PET as the sole carbon sources. The experiment was conducted over four weeks, with plastic samples incubated at 25°C, 35°C, and 45°C under pH conditions of 5, 7, and 9. Oxygen availability was controlled to create aerobic and anaerobic conditions. Plastic degradation efficiency was assessed by weight loss measurements, surface morphology analysis via scanning electron microscopy, and microbial growth monitoring through optical density (OD600) measurements. Statistical analyses were performed using one-way ANOVA and t-tests, with p-values &lt; 0.05 considered significant. Results: Microbial degradation efficiency was significantly influenced by environmental stressors (p &lt; 0.05). The highest degradation rates were observed at 35°C and pH 7, with PE and PET weight loss reaching 8.5 ± 0.5% and 7.0 ± 0.4%, respectively. Lower degradation occurred at 25°C (4.2 ± 0.3% for PE, 2.8 ± 0.2% for PET) and 45°C (3.1 ± 0.2% for PE, 1.9 ± 0.2% for PET). Similarly, microbial activity was highest at pH 7 (OD600 = 1.41 ± 0.07) and declined under acidic (pH 5) and alkaline (pH 9) conditions. Oxygen availability significantly affected degradation rates, with aerobic conditions yielding 10.1 ± 0.6% PE degradation and 7.8 ± 0.5% PET degradation, whereas anaerobic conditions resulted in markedly lower values (3.8 ± 0.3% for PE, 2.5 ± 0.2% for PET) (p &lt; 0.05). Conclusion: This study confirms that temperature, pH, and oxygen availability significantly impact microbial plastic degradation. Optimal conditions of 35°C, pH 7, and aerobic environments yielded the highest degradation efficiency. These findings support the development of biotechnological strategies to enhance microbial plastic biodegradation, contributing to sustainable waste management solutions.

An in vitro Evaluation of Periodontal Ligament Cell Viability in Honey as a Transport Medium for an Avulsed Tooth

Abstract Background Dental avulsion is the most severe form of injury to a tooth, and its prognosis is majorly affected by the type of the storage medium prior to re-implantation. Honey is a readily available household substance with anti-inflammatory properties. However, there is paucity of data regarding its use as a transport medium for avulsed teeth. Therefore, this study aims to evaluate the viability of periodontal Ligament (PDL) cells stored in honey and other recommended transport media. Materials and Methods An in vitro study involving the culture of PDL cells, harvested from premolars freshly extracted for orthodontic reasons. The cells were exposed to Dulbecco’s Minimum Essential Medium (DMEM), honey, and Hanks Balanced Salt Solution (HBSS) at room temperature, and their viability was tested with the tetrazolium salt-based colorimetric (MTT) assay after 30 min, 2 h, and 24 h. The Optical Density (OD) of the cells were assessed with a spectrophotometer. The Mean Optical Density (MOD) of the cells stored in DMEM was compared with those of cells in other media at each interval with the independent t-test at P &lt; 0.05 Results The MOD of cells stored in DMEM, honey, and HBSS over the 24-h period ranged between 0.32 ± 0.04 −0.31 ± 0.05; 0.30 ± 0.07−0.28 ± 0.07, and 0.23 ± 0.0−0.21 ± 0.01, respectively. The mean difference between the OD of cells stored in honey and those in DMEM at the end of the study period was 0.03 (t = 1.37; P = 0.18). Conclusion There was no difference in the viability of PDL cells stored in honey and DMEM over the study period.

Enhanced Salt Tolerance of Pea (Pisum sativum L.) Seedlings Illuminated by LED Red Light

Light quality is an important variable affecting plant growth, so we aimed to explore the impact of light quality on plants under salt stress. The salt tolerance of pea (Pisum sativum L.) seedlings illuminated by LED red light and 4:1 of red/blue light in a hydroponic system was evaluated at three salinity levels (0, 50, and 100 mmol/L of NaCl) for their morphological and physiological parameters and their root growth characteristics in response to salt stress. Results demonstrated that, as salt stress intensified, the plant height, aboveground fresh/dry mass, root growth indices, and chlorophyll content of pea seedlings exhibited a decreasing trend, while the malondialdehyde (MDA) content and the activity of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in leaves increased. Also, more sodium (Na⁺) but less potassium (K⁺) ions were detected due to the change in electrolyte balance. Compared with pea seedlings under no salt stress, the growth rate, plant height, and K⁺ ion content significantly increased with the red light treatments, but both lights did not affect the aboveground fresh/dry mass, chlorophyll content, or root growth index. Under medium salt stress (50 mmol/L), red light helped generate more chlorophylls by 17.06%, accelerate leaf electrolyte exudation by 23.84%, accumulate more K⁺ ions by 46.32%, and increase the K⁺/Na⁺ ratio by 45.45%. When pea seedlings were stressed by 100 mmol/L salinity stress, red light was able to maintain the leaf chlorophyll level by 114.66%, POD enzyme activity by 157.78%, MDA amount by 14.16%, leaf and stem electrolyte leakage rate by 38.76% and 21.80%, respectively, K⁺ ion content by 45.47%, and K⁺/Na⁺ ratio by 69.70%. In conclusion, the use of red light has proven to enhance the salt tolerance of pea seedlings in a hydroponic system, which can and should be a promising approach to prime pea seedlings for more salt tolerance.

Glyphosate Tolerant Bacteria from Rhizosphere of Kangkong (Ipomoea reptans Poir.) and Soybean (Glycine max L.)

The use of organophosphate pesticides has some risks for human health and environment. One of the organophosphate pesticides is glyphosate. Various methods used to detoxify organophosphates including chemical methods, incineration, and landfills, produce acid and alkaline compounds, leaching pesticides around land and groundwater areas, as well as toxic emissions to the environment. The bacteria with this ability can be isolated from areas contaminated with glyphosate. Kangkong (Ipomoea reptans) and soybean (Glycine max) were chosen because of these plants are commonly found in rice fields which are areas that are frequent exposure to pesticide. The interaction between rhizosphere bacteria and plants as well as the composition of existing bacteria are closely related to the remediation occured. Kangkong and soybeans (2 weeks) were treated with glyphosate 377 mM. Soil pH was measured in third and seventh days after treat with glyphosate. The bacteria were isolated a week after treatment with glyphosate, and cultured in NA medium containing 5 mM and 10 mM glyphosate. The growing bacteria were selected and re-cultured in NA + glyphosate 10 mM medium. The selected isolates were tested for glyphosate degradation ability in Mineral Salt Media containing glyphosate 5 mM and glucose 50 mg/L. Eight isolates of bacteria grew in media containing glyphosate, i.e. Kd1, Kd2, Kd3, Kd4, Kd5 from soybeans rhizosphere, and K1, K3, K4 from spinach rhizosphere. The isolate Kd4 and K4 grew more abundantly compared the other isolates, exhibited good tolerant of glyphosate. From glyphosate degrading test, the isolate from soybean rhizosphere showed more tolerance than the isolate from kangkong rhizosphere. The molecular identification revealed that both isolates belong to species Bacillus mycoides.

P-1087. Novel Antisense Wide-Range Peptide Nucleic Acids Coated on Polystyrene Plates to Prevent Bacterial Biofilm

Abstract Background Biofilms are three dimensional communities of microorganisms that are encased in self-produced extracellular polymeric substances. Biofilms play a key role in device-associated infections, including catheter-associated urinary tract infections, largely because they protect microorganisms from standard antimicrobial therapies. Antisense synthetic peptide nucleic acids (PNAs) are an emerging approach to inhibiting specific components of gene expression. Several regulatory and motility genes are relatively conserved across biofilm forming Gram-negative bacilli, such as rpoS, amrZ, rsmA, and motA. In the present study, wide range PNAs (wrPNAs) were developed by our group to exploit these conserved targets, offering a mechanism for precise, yet broad, biofilm inhibition. The impact of wrPNAs on Gram-negative biofilms and bacterial viability were investigated. Methods wrPNAs: Antisense-wrPNAs (patent pending) were designed using NCBI Blast to select a region inclusive of the start codon. The wrPNAs ranged from 12 to 14 basepairs, conjugated with a cell-penetrating peptide and O-linker, and were synthesized by PNA Bio (Figure 1). Quantify biofilm biomass: Bacterial isolates were grown in a 96-well polystyrene plate in minimal salt medium with wrPNA treatment (10 µM each) and incubated at 30˚C for 24hr in a humid chamber. Biofilms were stained with 0.1% crystal violet, solubilized in 33% glacial acetic acid, and measured at OD590 nm. Quantify bacterial viability: 10-fold serial dilutions and direct stamping onto agar plates. Statistical analysis: P values were determined using unpaired t-tests or one-way ANOVA with followup tests comparing the mean of each column to the control column (alpha = 0.05). Results wrPNA treatment significantly reduced biofilm biomass for their intended species (Figure 2). A cocktail of PNAs had a bactericidal effect on Pseudomonas aeruginosa, but wrPNA treatment had minimal effect on bacterial viability for the other Gram-negative bacilli tested (Figure 2). Conclusion wrPNAs against global regulator genes and a motility regular gene reduced biofilm biomass for their intended species. Future work will look at combination therapy to improve bactericidal effects as well as methods for coating treatments onto catheter and device surfaces. Disclosures All Authors: No reported disclosures

Biodegradation potential of low-density polyethylene (LDPE) using Aspergillus niger and Phanerochaete chrysosporium

Low-density polyethylene (LDPE) is one of the most predominant and widely used plastic types on earth. This study investigated the degradation of low-density polyethylene (LDPE) with two fungal species. Aspergillus niger and Phanerochaete chrysosporium were the two fungal species that were isolated from garbage soil and screened in two medium broths independently i.e. Czapek-Dox broth (CDB) and Mineral salt medium (MSM). The broth was used to inoculate both fungi species in flasks where LDPE polymer as source of carbon. Non pre-treatment LDPE samples were incubated for a 20-day biodegradation process. Microbial population, biomass layer, pH were maintained during the process. The final biodegradation percentage after 20 days was 40% in CDB and minimum degradation rate in MSM. The morphological, structural and functional group alterations on LDPE were assessed using scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR). DSC analytical method confirmed the LDPE polymer chain breakdown. LDPE exposed to fungi species was reported to show crystallinity and crystal size differences with peak intensity at 21.4°. Through the analysis of FTIR peaks were observed at 2927 and 2523 cm−1. This research highlights the potential of both fungi for biodegradation of LDPE. However, with these findings adaptive metabolic pathways for LDPE biodegradation need to be linked and studied.Graphical

Interaction between nitrate and trichloroethene bioreduction in mixed anaerobic cultures.

Bioremediation of trichloroethene (TCE)-contaminated sites often leads to groundwater acidification, while nitrate-polluted sites tend to generate alkalization. TCE and nitrate often coexist at contaminated sites; however, the pH variation caused by nitrate self-alkalization and TCE self-acidification and how these processes affect nitrate reduction and reductive dichlorination, have not been studied. This study investigated the interaction between nitrate and TCE, two common groundwater co-contaminants, during bioreduction in serum bottles containing synthetic mineral salt media and microbial consortia. Our results showed that TCE concentrations up to 0.3 mM stimulated nitrate reduction, while the effect of nitrate on TCE reductive dechlorination was more complex. Nitrate primarily inhibited the reduction of TCE to dichloroethene (DCE) but enhanced the reduction of vinyl chloride (VC) to ethene. Mechanistic analysis suggested that this inhibition was due to the thermodynamic favorability of nitrate reduction over TCE reduction, while the promotion of VC reduction was linked to pH stabilization via self-alkalization. As the initial nitrate concentration increased from 0 to 3 mM, the relative abundance of putatively denitrifying genera, such as Petrimonas and Trichlorobacter, increased. However, the abundance of fermentative Clostridium sharply declined from 31.11 to 1.51%, indicating strong nitrate inhibition. Additionally, the relative abundance of Dehalococcoides, a genus capable of reducing TCE to ethene, slightly increased from 23.91 to 24.26% at nitrate concentrations up to 0.3 mM but decreased to 18.65% as the nitrate concentration increased to 3 mM, suggesting that Dehalococcoides exhibits a degree of tolerance to high nitrate concentrations under specific conditions. Overall, our findings highlight the potential for simultaneous reduction of TCE and nitrate, even at elevated concentrations, facilitated by self-regulating pH control in anaerobic mixed dechlorinating consortia. This study provides novel insights into bioremediation strategies for addressing co-contaminated sites.

Exploring the intricate studies on low-density polyethylene (LDPE) biodegradation by Bacillus cereus AP-01, isolated from the gut of Styrofoam-fed Tenebrio molitor larvae.

This study aims to investigate the biodegradation potential of a gut bacterial strain, Bacillus cereus AP-01, isolated from Tenebrio molitor larvae fed Styrofoam, focusing on its efficacy in degrading low-density polyethylene (LDPE). The biodegradation process was evaluated through a series of assays, including clear zone assays, biodegradation assays, and planktonic cell growth assessments in mineral salt medium (MSM) over a 28-day incubation period. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were employed to characterize the alterations in LDPE pellets, followed by molecular characterization. Over three months, sterile soil + LDPE pellets were treated with different concentrations of gut bacterial strain. The degradation capabilities were assessed by measuring pH, total microbial counts, carbon dioxide evolution, weight loss, and conducting phase contrast microscopy and mechanical strength tests. Results demonstrated that MSM containing LDPE as a carbon source with gut bacterial strain produced a clear zone and enhanced planktonic cell growth. FTIR analysis revealed the formation of new functional groups in the LDPE, while SEM images displayed surface erosion and cracking, providing visual evidence of biodegradation. Molecular characterization confirmed the strain as Bacillus cereus AP-01 (NCBI Accession Number: OR288218.1). A 10% inoculum concentration of Bacillus cereus AP-01 exhibited increased soil bacterial counts, carbon dioxide evolution, and pH levels, alongside a notable weight loss of 30.3% in LDPE pellets. Mechanical strength assessments indicated substantial reductions in tensile strength (7.81 ± 0.84 MPa), compression (4.92 ± 0.53 MPa), hardness (51.96 ± 5.62 shore D), flexibility (10.62 ± 1.15 MPa), and impact resistance (14.79 ± 0.94 J). These findings underscore the biodegradation potential of Bacillus cereus AP-01, presenting a promising strategy for addressing the global LDPE pollution crisis.

Anthracene-Conjugated Steroidal Amphiphiles: Soft Functional Materials Exhibiting Supramolecular Aggregation Induced Enhanced Emission with Potential Applications as Drug Carriers and Fluorescent Bioprobes.

Bile salts (BS) are naturally occurring steroidal biosurfactants. The ease of functionalization of BSs has boosted their use as inexpensive building blocks for the fabrication of a broad set of value-added soft functional materials. In the present work, three fluorescent bile acid (FBA) derivatives have been synthesized by conjugating anthracene at the side chain of lithocholic acid, deoxycholic acid, and cholic acid to understand the effect of the nature of the steroid nucleus on their physicochemical properties. In an aqueous medium, the FBAs showed a strong supramolecular aggregation propensity, even in the micromolar concentration range, which is in contrast to their BS analogues that form micelles mostly in the millimolar range. The FBA aggregation leads to a prearranged geometry in the ground state with a favorable orientation of anthracene units for excimer formation on excitation, leading to supramolecular aggregation-induced enhanced emission (AIEE). A detailed investigation reveals the pivotal role of the steroidal skeleton in their aggregation propensity and optical behavior. The FBA assemblies, with ordered structures plus anthracene being a part of their building blocks, are endowed with interesting properties different from those in dilute organic media, which makes them extremely attractive for diverse applications, e.g., as potential drug carriers owing to their ability to serve as efficient hosts for the protective encapsulation of hydrophobic guests; as membrane probes and bioimaging agents due to their efficient membrane permeability and cell-imaging ability; and as system probes because of their remarkable sensitivity toward the aggregation process of natural bile salts in the aqueous medium. Therefore, the present study not only enhances the fundamental understanding of this unique class of amphiphiles but also opens new prospects in tailoring novel self-assembled soft functional materials. Moreover, it offers a benchmark for developing BS-based fluorescent derivatives with unique photophysical characteristics for applications as potential bioprobes.

Physico‐Chemical Investigation of Clouding Behavior, Thermodynamics, and Interaction Forces for Triton X‐100 and Tetracaine Hydrochloride Mixture: Assessment of Effects of Electrolytes

AbstractAssessment of clouding development and thermodynamic parameters of the surfactant‐drug mixtures are crucial for chemists, industrialists, and researchers because of the numerous possible uses of this combined mixture in the pharmaceutical sectors. Cloud point (CP) of the surfactant triton X‐100 (TX‐100) and tetracaine hydrochloride (TCH) drug mixed system was explored in aqueous and aqueous inorganic salts (NaCl, NaBr, Na2SO4, and Na3PO4) media. In an aqueous medium, an enhanced pattern in the CP values of amphiphile used was observed with rising concentration of TCH drug. On the contrary, the CP values of study mixture were followed to be reduced through the growth of inorganic salts concentration and follows the sequential order as: . The decreased CP indicates the reduction of solubility of the investigation system in salts media in comparison to aqueous medium. Different thermodynamic parameters were determined at CP and discussed properly. Entropy () and enthalpy () values for clouding of TX‐100 + TCH mixtures were obtained positive in aqueous media and negative in electrolytes media. According to the magnitudes of and , the electrostatic and hydrophobic interactions are the main forces operating between TX‐100 and TCH. In this instance, the intrinsic enthalpy ) and compensation temperature (Tc) were assessed, compared, and discussed logically.