Decolorization and detoxification of direct blue 5B by a Marinobacter-dominated halo-thermoalkalophilic consortium.

Azo dye-containing sewage is commonly detected at high salinity, temperature and pH. In this study, a halo-thermoalkalophilic azo dye decolorization consortium was enriched and named "consortium HL". Consortium HL which was dominated by Marinobacter (84.30%), Desulfocurvibacter (1.89%), and Pseudomonas (1.85%), was able to completely decolorize Direct Blue 5B (DB5) during incubation with the material at 5% salinity, 50 °C, and pH 9 for 30 h. The decolorization mechanism was proposed based on combined metagenomic analysis, GC‒MS, and enzymatic activity detection. The action of the consortium HL showed great tolerance to variations in salinity, temperature and pH. A phytotoxicity study indicated that the metabolic intermediates showed no significant toxicity to the generation of Cucumis sativus and Oryza sativa seeds. This study, in which azo dye decolorization and degradation under high-salt, high-temperature and high-alkalinity conditions were investigated and deeply analyzed by metagenomic information, is the first report regarding the ability of Marinobacter to decolorize azo dyes at high temperatures.

Methyl Red degradation by a subseafloor fungus Schizophyllum commune 15R-5-F01: efficiency, pathway, and product toxicity.

Synthetic dyes pose a significant environmental threat due to their complex structures and resistance to microbial degradation. S. commune 15R-5-F01 exhibited over 96% degradation efficiency of Methyl Red in a medium with 100 mg L-1 Methyl Red within 3 h. The fungus demonstrated adaptability to various environmental conditions, including different pH levels, temperatures, oxygen concentrations, salinity, and heavy metals. S. commune 15R-5-F01 is capable of achieving repeated cycles of Methyl Red reduction with sustained degradation duration minimum of 6 cycles. It showed a maximum Methyl Red biodegradation capacity of at least 558 mg g-1 dry mycelia and a bioadsorption capacity of 57 mg g-1. Gas chromatography-mass spectrometry analysis confirmed the azo reduction of Methyl Red into N,N-dimethyl-p-phenylenediamine and 2-aminobenzoic acid. Enzymatic activity assays indicated the involvement of lignin peroxidases, laccases, and manganese peroxidase in the biodegradation process. Phytotoxicity tests on Triticum eastivum, Oryza sativa, and Vigna umbellata seeds revealed reduced toxicity of the degradation products compared to Methyl Red. This study identifies S. commune 15R-5-F01 as a viable candidate for the sustainable degradation of synthetic dyes in industrial wastewater.

Heterologous expression and characterization of a dye-decolorizing peroxidase from Ganoderma lucidum, and its application in decolorization and detoxifization of different types of dyes.

Dye-decolorizing peroxidases (DyPs) belong to a novel superfamily of heme peroxidases that can oxidize recalcitrant compounds. In the current study, the GlDyP2 gene from Ganoderma lucidum was heterologously expressed in Escherichia coli, and the enzymatic properties of the recombinant GlDyP2 protein were investigated. The GlDyP2 protein could oxidize not only the typical peroxidase substrate ABTS but also two lignin substrates, namely guaiacol and 2,6-dimethoxy phenol (DMP). For the ABTS substrate, the optimum pH and temperature of GlDyP2 were 4.0 and 35 °C, respectively. The pH stability and thermal stability of GlDyP2 were also measured; the results showed that GlDyP2 could function normally in the acidic environment, with a T50 value of 51 °C. Moreover, compared to untreated controls, the activity of GlDyP2 was inhibited by 1.60 mM of Mg2+, Ni2+, Mn2+, and ethanol; 0.16 mM of Cu2+, Zn2+, methanol, isopropyl alcohol, and Na2EDTA·2H2O; and 0.016 mM of Fe2+ and SDS. The kinetic constants of recombinant GlDyP2 for oxidizing ABTS, Reactive Blue 19, guaiacol, and DMP were determined; the results showed that the recombination GlDyP2 exhibited the strongest affinity and the most remarkable catalytic efficiency towards guaiacol in the selected substrates. GlDyP2 also exhibited decolorization and detoxification capabilities towards several dyes, including Reactive Blue 19, Reactive Brilliant Blue X-BR, Reactive Black 5, Methyl Orange, Trypan Blue, and Malachite Green. In conclusion, GlDyP2 has good application potential for treating dye wastewater.

Robust peroxidase from Bacillus mojavensis TH309: Immobilization on walnut shell hydrochar and evaluation of its potential in dye decolorization.

Peroxidases have received considerable attention as a cost-effective and environmentally friendly catalyst for bioremediation. Their rapid activity loss under harsh environmental conditions and inability to be used repetitively limit their exploitation in real-world wastewater treatment. First, a peroxidase was produced extracellularly by Bacillus mojavensis TH309 and purified 8.12-fold with a final yield of 47.10 % using Sephadex G-100 superfine resin. The pure peroxidase (BmPer) possessed a relatively low molecular weight of ~21 kDa and was active against L-DOPA on acrylamide gel after electrophoresis. BmPer was immobilized by adsorption functionalized walnut shell hydrochar (WsH) with 61.99 ±â€¯1.34 % efficiency and 37.07 ±â€¯4.16 % activity loss. BmPer and its immobilized form (WsH-BmPer) exhibited maximum activity at 50 °C and pH 9. WsH-BmPer exhibited 3.23-, 2.37-, 1.65-, and 2.25-fold longer half-life than BmPer at 50, 60, 70, and 80 °C, respectively. Immobilization significantly enhanced the stability of the enzyme under acidic conditions. BmPer and WsH-BmPer showed maximal activity in the presence of 1 % salt and retained more than 85 % of their activity even after pre-incubation with 2.5 M salt for 60 min at 50 °C. Their catalytic efficiency was significantly stimulated by pre-incubation with Triton X-100 (1 mM), Tween20 (1 mM), and Mg2+ (1 and 10 mM). Immobilization strongly reduced the loss of activity caused by inhibitors including Ba2+, Hg2+, and Cu2+. Moreover, both forms of the enzyme were compatible with solvents. The Michaelis constant (Km) values of BmPer and WsH-BmPer were 0.88 and 2.66 mM for 2,4 DCP, respectively. WsH-BmPer peroxidase maintained about 82 % and 85 % of its activity when stored at 4 °C for 30 days and reused for up to 10 cycles, respectively. Furthermore, it decolorized Cibacron red (CR), Poly R-478 (PR), Remazol Brilliant Blue R (RBBR), and Methyl red (MR) dyes by 60.13 %, 91.34 %, 86.41 %, and 50.51 % within 60 min, respectively.

Potential of halophiles and alkaliphiles in bioremediation of azo dyes-laden textile wastewater: a review.

Azo dye-laden textile wastewater must be treated before release due to various health and environmental concerns. Bioremediation of textile wastewater, however, is a challenge owing to its alkaline and saline nature as mesophilic microbes, in general, are either not able to thrive or show less efficiency under such hostile environment. Thus, pre-treatment for neutralization or salinity removal becomes a prerequisite before applying microbes for treatment, causing extra economical and technical burden. Extremophilic bacteria can be the promising bioremediating tool because of their inherent ability to survive and show toxicants removal capability under such extreme conditions without need of pre-treatment. Among extremophiles, halophilic and alkaliphilic bacteria which are naturally adapted to high salt and pH are of special interest for the decolorization of saline-alkaline-rich textile wastewater. The current review article is an attempt to provide an overview of the bioremediation of azo dyes and azo dye-laden textile wastewater using these two classes of extremophilic bacteria. The harmful effects of azo dyes on human health and environment have been discussed herein. Halo-alkaliphilic bacteria circumvent the extreme conditions by various adaptations, e.g., production of certain enzymes, adjustment at the protein level, pH homeostasis, and other structural adaptations that have been highlighted in this review. The unique properties of alkaliphiles and halophiles, to not only sustain but also harboring high dye removal competence at high pH and salt concentration, make them a good candidate for designing future bioremediation strategies for the management of alkaline, salt, and azo dye-laden industrial wastewaters.

Decolorization of Lignin for High-Resolution 3D Printing of High Lignin-Content Composites.

Lignin, one of the most abundant biomaterials and a large-scale industrial waste product, is a promising filler for polymers as it reduces the amount of fossil resources and is readily available. 3D printing is well-known for producing detailed polymer structures in small sizes at low waste production. Especially light-assisted 3D printing is a powerful technique for production of high-resolution structures. However, lignin acts as a very efficient absorber for UV and visible light limiting the printability of lignin composites, reducing its potential as a high-volume filler. In this work, the decolorization of lignin is presented for high-resolution 3D printing of biocomposites with lignin content up to 40 wt.%. Organosolv lignin (OSL) is decolorized by an optimized low-energy process of acetylation and subsequent UV irradiation reducing the UV absorbance by 71%. By integration of decolorized lignin into bio-based tetrahydrofurfuryl acrylate (THFA), a lignin content of 40 wt.% and a resolution of 250 µm is achieved. Due to the reinforcing properties of lignin, the stiffness and strength of the material is increased by factors of 15 and 2.3, respectively. This work paves the way for the re-use of a large amount of lignin waste for 3D printing of tough materials at high resolution.

New bacterial strains isolated from Tunisian biotopes: A sustainable enzymatic approach for decolorization and detoxification of Congo Red and Malachite Green.

Seven bacterial strains, isolated from various Tunisian biotopes, were investigated for Congo Red (CR) and Malachite Green (MG) decolorization. The isolated strains underwent morphological and biochemical tests, including assessments for antibiotic sensitivity as well as biofilm formation. One selected strain, ST11, was partially identified as Paenibacillus sp. strain ST11. The newly isolated crude bacterial filtrates (NICBFs) effectively decolorized CR and MG. Specifically, six and seven NICBFs were found to be effective for degrading CR (150 mg l-1) and MG (50 mg l-1), respectively. Under non-optimized conditions, CR and MG could be decolorized up to 80% within 6-12 h. The degradation products of CR and MG, characterized by UV-visible and FT-IR techniques, demonstrated both decolorization and transformation, highlighting the role of enzymes in dye degradation. Phytotoxicity and cytotoxicity studies evaluated the impact of treated and untreated CR and MG. Some NICBFs showed promise as powerful biological tools, reducing and sometimes detoxifying CR and MG, commonly used as fertilizers. The potential applications of these NICBFs in decolorization and bioremediation of dye-rich textile effluents were explored. The screening also identified environmentally friendly, cost-effective bacterial strains adaptable to various conditions through phytotoxicity and cytotoxicity studies.

Regulation of dye-decolorizing peroxidase gene expression in Pleurotus ostreatus grown on glycerol as the carbon source.

Dye-decolorizing peroxidases (DyPs) (E.C. 1.11.1.19) are heme peroxidases that catalyze oxygen transfer reactions similarly to oxygenases. DyPs utilize hydrogen peroxide (H2O2) both as an electron acceptor co-substrate and as an electron donor when oxidized to their respective radicals. The production of both DyPs and lignin-modifying enzymes (LMEs) is regulated by the carbon source, although less readily metabolizable carbon sources do improve LME production. The present study analyzed the effect of glycerol on Pleurotus ostreatus growth, total DyP activity, and the expression of three Pleos-dyp genes (Pleos-dyp1, Pleos-dyp2 and Pleos-dyp4), via real-time RT-qPCR, monitoring the time course of P. ostreatus cultures supplemented with either glycerol or glucose and Acetyl Yellow G (AYG) dye. The results obtained indicate that glycerol negatively affects P. ostreatus growth, giving a biomass production of 5.31 and 5.62 g/L with respective growth rates (micra; m) of 0.027 and 0.023 h-1 for fermentations in the absence and presence of AYG dye. In contrast, respective biomass production levels of 7.09 and 7.20 g/L and growth rates (µ) of 0.033 and 0.047 h-1 were observed in equivalent control fermentations conducted with glucose in the absence and presence of AYG dye. Higher DyP activity levels, 4,043 and 4,902 IU/L, were obtained for fermentations conducted on glycerol, equivalent to 2.6-fold and 3.16-fold higher than the activity observed when glucose is used as the carbon source. The differential regulation of the DyP-encoding genes in P. ostreatus were explored, evaluating the carbon source, the growth phase, and the influence of the dye. The global analysis of the expression patterns throughout the fermentation showed the up- and down- regulation of the three Pleos-dyp genes evaluated. The highest induction observed for the control media was that found for the Pleos-dyp1 gene, which is equivalent to an 11.1-fold increase in relative expression (log2) during the stationary phase of the culture (360 h), and for the glucose/AYG media was Pleos-dyp-4 with 8.28-fold increase after 168 h. In addition, glycerol preferentially induced the Pleos-dyp1 and Pleos-dyp2 genes, leading to respective 11.61 and 4.28-fold increases after 144 h. After 360 and 504 h of culture, 12.86 and 4.02-fold increases were observed in the induction levels presented by Pleos-dyp1 and Pleos-dyp2, respectively, in the presence of AYG. When transcription levels were referred to those found in the control media, adding AYG led to up-regulation of the three dyp genes throughout the fermentation. Contrary to the fermentation with glycerol, where up- and down-regulation was observed. The present study is the first report describing the effect of a less-metabolizable carbon source, such as glycerol, on the differential expression of DyP-encoding genes and their corresponding activity.

Harnessing iron materials for enhanced decolorization of azo dye wastewater: A comprehensive review.

Highly colored azo dye-contaminated wastewater poses significant environmental threats and requires effective treatment before discharge. The anaerobic azo dye treatment method is a cost-effective and environmentally friendly solution, while its time-consuming and inefficient processes present substantial challenges for industrial scaling. Thus, the use of iron materials presents a promising alternative. Laboratory studies have demonstrated that systems coupled with iron materials enhance the decolorization efficiency and reduce the processing time. To fully realize the potential of iron materials for anaerobic azo dye treatment, a comprehensive synthesis and evaluation based on individual-related research studies, which have not been conducted to date, are necessary. This review provides, for the first time, an extensive and detailed overview of the utilization of iron materials for azo dye treatment, with a focus on decolorization. It assesses the treatment potential, analyzes the influencing factors and their impacts, and proposes metabolic pathways to enhance anaerobic dye treatment using iron materials. The physicochemical characteristics of iron materials are also discussed to elucidate the mechanisms behind the enhanced bioreduction of azo dyes. This study further addresses the current obstacles and outlines future prospects for industrial-scale application of iron-coupled treatment systems.

Synergistic enhancement of microbes-to-pollutants and inter-microbes electron transfer by Fe, N modified ordered mesoporous biochar in anaerobic digestion.

Extracellular electron transfer was essential for degrading recalcitrant pollutants by anaerobic digestion (AD). Therefore, existing studies improved AD efficiency by enhancing the electron transfer from microbes-to-pollutants or inter-microbes. This study synthesized a novel Fe, N co-doped biochar (Fe, N-BC), which could enhance both the microbes-to-pollutants and inter-microbes electron transfer in AD. Detailed characterization data indicated that Fe, N-BC has an ordered mesoporous structure, high specific surface area (463.46 m2/g), and abundant redox functional groups (Fe2+/Fe3+, pyrrolic-N), which translate into excellent biocompatibility and electrochemical properties of Fe, N-BC. By adding Fe, N-BC, the stability and efficiency of the medium-temperature AD system in the treatment of methyl orange (MO) wastewater were improved: obtained a high degradation efficiency of MO (96.8 %) and enhanced the methane (CH4) production by 65 % compared to the control group. Meanwhile, Fe, N-BC reduced the accumulation of volatile fatty acids in the AD system, and the activity of anaerobic granular sludge electron transport system and coenzyme F420 was enhanced. In addition, Fe, N-BC showed positive enrichment of azo dyes decolorization bacteria (Georgenia) and direct interspecies electron transfer (DIET) synergistic partners (Syntrophobacter, Methanosarcina). Overall, the rapid degradation of MO and enhanced CH4 production in AD systems by Fe, N-BC is associated with enhancing two electronic pathways, i.e., microbes to MO and DIET between syntrophic bacteria and methanogenic archaea. This study introduced an enhanced "two-pathways of electron transfer" theory, realized by Fe, N-BC. These findings provided new insights into the interactions within AD systems and offer strategies for enhancing their performance with recalcitrant pollutants.

Insights on kraft lignin degradation in an anaerobic environment.

Lignin is an aromatic macromolecule and one of the main constituents of lignocellulosic materials. Kraft lignin is generated as a residual by-product of the lignocellulosic biomass industrial process, and it might be used as a feedstock to generate low molecular weight aromatic compounds. In this study, we seek to understand and explore the potential of ruminal bacteria in the degradation of kraft lignin. We established two consortia, KLY and KL, which demonstrated significant lignin-degrading capabilities. Both consortia reached maximum growth after two days, with KLY showing a higher growth and decolorization rate. Additionally, SEM analysis revealed morphological changes in the residual lignin from both consortia, indicating significant degradation. This was further supported by FTIR spectra, which showed new bands corresponding to the C-H vibrations of guaiacyl and syringyl units, suggesting structural transformations of the lignin. Taxonomic analysis showed enrichment of the microbial community with members of the Dickeya genus. Seven metabolic pathways related to lignin metabolism were predicted for the established consortia. Both consortia were capable of consuming aromatic compounds such as 4-hydroxybenzoic acid, syringaldehyde, acetovanillone, and syringic acid, highlighting their capacity to convert aromatic compounds into commercially valuable molecules presenting antifungal activity and used as food preservatives as 4-hydroxyphenylacetic, 3-phenylacetic, and phenylacetic acids. Therefore, the microbial consortia shown in the present work are models for understanding the process of lignin degradation and consumption in bacterial anaerobic communities and developing biological processes to add value to industrial processes based on lignocellulosic biomass as feedstock.

Exploring the decolorization efficiency and biodegradation mechanisms of different functional textile azo dyes by Streptomyces albidoflavus 3MGH.

Efficiently mitigating and managing environmental pollution caused by the improper disposal of dyes and effluents from the textile industry is of great importance. This study evaluated the effectiveness of Streptomyces albidoflavus 3MGH in decolorizing and degrading three different azo dyes, namely Reactive Orange 122 (RO 122), Direct Blue 15 (DB 15), and Direct Black 38 (DB 38). Various analytical techniques, such as Fourier Transform Infrared (FTIR) spectroscopy, High-Performance Liquid Chromatography (HPLC), and Gas Chromatography-Mass Spectrometry (GC-MS) were used to analyze the degraded byproducts of the dyes. S. albidoflavus 3MGH demonstrated a strong capability to decolorize RO 122, DB 15, and DB 38, achieving up to 60.74%, 61.38%, and 53.43% decolorization within 5 days at a concentration of 0.3 g/L, respectively. The optimal conditions for the maximum decolorization of these azo dyes were found to be a temperature of 35 °C, a pH of 6, sucrose as a carbon source, and beef extract as a nitrogen source. Additionally, after optimization of the decolorization process, treatment with S. albidoflavus 3MGH resulted in significant reductions of 94.4%, 86.3%, and 68.2% in the total organic carbon of RO 122, DB 15, and DB 38, respectively. After the treatment process, we found the specific activity of the laccase enzyme, one of the mediating enzymes of the degradation mechanism, to be 5.96 U/mg. FT-IR spectroscopy analysis of the degraded metabolites showed specific changes and shifts in peaks compared to the control samples. GC-MS analysis revealed the presence of metabolites such as benzene, biphenyl, and naphthalene derivatives. Overall, this study demonstrated the potential of S. albidoflavus 3MGH for the effective decolorization and degradation of different azo dyes. The findings were validated through various analytical techniques, shedding light on the biodegradation mechanism employed by this strain.

The performance of quaternary-ammonium chitosan in wastewater treatment: The overlooked role of solubility.

Quaternary-ammonium chitosan (CT-CTA) is a popular water treatment agent, and its electropositivity and cation strength are improved compared with chitosan. The use of CT-CTA is widely advocated to remove suspended particles and organic matter from wastewater. However, the solubility of CT-CTA is an important factor affecting the performance of CT-CTA, which is a neglected problem in previous studies. In the study, CT-CTA with different solubilities were prepared by adjusting pH from 2 to 7 in preparation, and their applications were explored in wastewater. When the pH was 2, 2.5, or 3, the obtained CT-CTA was a dissolved state. The turbidity and color removal were 95 % - 98 % and 60 % - 74 %, respectively. When the pH was 4, 5, 6, or 7, the obtained CT-CTA was a solid state. The turbidity and color removal were 30 % - 63 % and 90 % - 97 %, respectively. For domestic-wastewater treatment, CT-CTA in a dissolved state removed 92 % of turbidity and 50 % of chemical oxygen demand (COD). CT-CTA in a solid state removed 86 % of turbidity and 64 % of COD with poly aluminum chloride (PAC). The results illustrated the performance of CT-CTA with different solubilities, which can broaden its application in wastewater treatment.

New magnetic nanocomposites based on hexafrite and keggin-type -type heteropolyanions: Synthesized and characterized for removal of environmental pollutants.

This research paper details the creation of innovative nanocomposites using the sol-gel technique, incorporating polyoxometalates SiW9Ba3 to stabilize ceramic particles of strontium ferrite (SrFe12O19) polymer and Chitosan (CS). The identification and confirmation of the nanocomposites obtained at each stage were carried out through the use of FT-IR, EDX, XRD, and FESEM analyses. To evaluate their ability to remove organic dyes, we analyzed the catalytic activity of these nanocomposites during photocatalytic detoxification procedures. With its exceptional photocatalytic properties, the nanocomposite (SiW9Ba3@SrFe12O19@Cs) was able to remove estamipride poison at an impressive rate of 85 % and xylene dye solution at an even higher rate of 98 %. In addition, an extensive examination was undertaken to explore the primary variables that influence process efficiency. The study suggests that ceramic nanocomposites incorporating heteropolyoxometalate may offer a viable approach to effectively eradicate pollutants from the environment.

Isolation and characterization of Stenotrophomonas pavanii GXUN74707 with efficient flocculation performance and application in wastewater treatment.

The identification of microorganisms with excellent flocculants-producing capability and optimization of the fermentation process are necessary for the wide-scale application of bioflocculants. Therefore, we isolated and identified a highly efficient flocculation performance strain of Stenotrophomonas pavanii GXUN74707 from the sludge. The optimal fermentation and flocculation conditions of strain S. pavanii GXUN74707 was in fermentation medium with glucose and urea as the carbon and nitrogen sources, respectively, at pH 7.0 for 36 h, which treatment of kaolin suspension with 0.5 mL of the fermentation broth resulted in a flocculation rate of 99.0%. The bioflocculant synthesized by strain S. pavanii GXUN74707 was found mainly in the supernatant of the fermentation broth. Chemical analysis revealed that the pure bioflocculant consisted of 79.70% carbohydrates and 14.38% proteins. The monosaccharide components of MBF-GXUN74707 are mainly mannose (5.96 µg/mg), galactose (1.86 µg/mg), and glucose (1.73 µg/mg). Infrared spectrometric analysis showed the presence of carboxyl (COO-), hydroxyl (-OH) groups. The SEM images showed clumps of rod-shaped bacteria with adhesion of extracellular products. Furthermore, the strain decolored dye wastewater containing direct black, direct blue, and Congo red by 89.2%, 95.1%, 94.1%, respectively. The chemical oxygen demand (COD) and biological oxygen demand (BOD) removal rates after treatment of aquaculture wastewater with the fermentation broth were 68% and 23%, respectively. This study is the first to report the performance and application of strain Stenotrophomonas pavanii in wastewater flocculation. The results indicate that strain S. pavanii is a good candidate for the production novel bioflocculants and demonstrates its potential industrial practicality in biotechnology processes.

Genome-Scale Investigation of the Regulation of azoR Expression in Escherichia coli Using Computational Analysis and Transposon Mutagenesis.

Bacterial azoreductases are enzymes that catalyze the reduction of ingested or industrial azo dyes. Although azoreductase genes have been well identified and characterized, the regulation of their expression has not been systematically investigated. To determine how different factors affect the expression of azoR, we extracted and analyzed transcriptional data from the Gene Expression Omnibus (GEO) resource, then confirmed computational predictions by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Results showed that azoR expression was lower with higher glucose concentration, agitation speed, and incubation temperature, but higher at higher culture densities. Co-expression and clustering analysis indicated ten genes with similar expression patterns to azoR: melA, tpx, yhbW, yciK, fdnG, fpr, nfsA, nfsB, rutF, and chrR (yieF). In parallel, constructing a random transposon library in E. coli K-12 and screening 4320 of its colonies for altered methyl red (MR)-decolorizing activity identified another set of seven genes potentially involved in azoR regulation. Among these genes, arsC, relA, plsY, and trmM were confirmed as potential azoR regulators based on the phenotypic decolorization activity of their transposon mutants, and the expression of arsC and relA was confirmed, by qRT-PCR, to significantly increase in E. coli K-12 in response to different MR concentrations. Finally, the significant decrease in azoR transcription upon transposon insertion in arsC and relA (as compared to its expression in wild-type E. coli) suggests their probable involvement in azoR regulation. In conclusion, combining in silico analysis and random transposon mutagenesis suggested a set of potential regulators of azoR in E. coli.

Production of Camellia oleifera Abel Seed Oil for Injection: Extraction, Analysis, Deacidification, Decolorization, and Deodorization.

Camellia seed oil (CSO), as a nutrient-rich edible oil, is widely used in foods, cosmetics, and other fields. In this work, the extraction, deacidification, decolorization, and deodorization processes of CSO were respectively optimized for meeting injectable oil standards. The results showed that the CSO extraction rate reached the highest level of 94% at optimized conditions (ultrasonic time, 31.2 min; reaction pH, 9.2; and reaction time, 3.5 h). The physicochemical indexes of CSO and 10 other vegetable oils were evaluated by the principal component analysis method, and the overall scores of vegetable oils were ranked as camellia seed oil > olive oil > rice oil > peanut oil > sesame oil > corn oil > soybean oil > sunflower oil > rapeseed oil > walnut oil > flaxseed oil. The physicochemical indicators of CSO were the most ideal among the 11 vegetable oils, which means that CSO is suitable as an injectable oil. Through the optimized processes of the deacidification, decolorization, and deodorization, the CSO acid value was reduced to 0.0515 mg KOH/g, the decolorization rate reached a maximum of 93.86%, and the OD430 was 0.015, meeting the requirement (≤0.045 of OD430) of injectable oil. After the deodorization process, these parameters of the refractive index, acid value, saponification value, iodine value, absorbance, unsaponifiable, moisture and volatiles, fatty acid composition, and heavy metal limits all met the pharmacopoeia standards of injectable oil in many countries and regions. The possibility of CSO as an injectable oil was first verified through refining-process optimization and nutritional index analysis, providing an important technical reference for the high-value utilization of vegetable oil.

Inhibition of Proliferation and Induction of Apoptosis in Prostatic Carcinoma DU145 Cells by Polysaccharides from Yunnan Rosa roxburghii Tratt.

OBJECTIVE: This study aimed to investigate methodologies for the extraction and purification of polysaccharides from Rosa roxburghii Tratt fruits and their impact on various cellular processes in prostate cancer DU145 cells, including survival rate, migration, invasion, cell cycle, and apoptosis. RESULTS: Compared to the control group, the polysaccharide exhibited a significant reduction in the viability, migration, and invasion rates of DU145 cells in a time- and dose-dependent manner within the polysaccharide-treated groups. Additionally, it effectively arrested the cell cycle of DU145 cells at the G0/G1 phase by downregulating the expressions of CDK-4, CDK-6, and Cyclin D1. Furthermore, it induced apoptosis by upregulating the expressions of Caspase 3, Caspase 8, Caspase 9, and BAX. METHODS: Polysaccharides were extracted from Rosa roxburghii Tratt sourced from Yunnan, China. Extraction and decolorization methods were optimized using response surface methodology, based on a single-factor experiment. Polysaccharide purification was carried out using DEAE-52 cellulose and Sephadex G-100 column chromatography. The optimal dosage of R. roxburghii Tratt polysaccharide affecting DU145 cells was determined using the CCK-8 assay. Cell migration and invasion were assessed using transwell and scratch assays. Flow cytometry was employed to analyze the effects on the cell cycle and apoptosis. Western blotting and Quantitative real-time PCR were utilized to examine protein and mRNA expressions in DU145 cells, respectively. CONCLUSIONS: Rosa roxburghii Tratt polysaccharides, consisting of D-mannose, L-rhamnose, N-acetyl-D-glucosamine, D-galacturonic acid, D-glucose, D-galactcose, D-xylose, L-arabinose, and L-fucose, possess the ability to hinder DU145 cell proliferation, migration, and invasion while inducing apoptosis through the modulation of relevant protein and gene expressions.

Microalgal and activated sludge processing for biodegradation of textile dyes.

The textile industry contributes substantially to water pollution. To investigate bioremediation of dye-containing wastewater, the decolorization and biotransformation of three textile azo dyes, Red HE8B, Reactive Green 27, and Acid Blue 29, were considered using an integrated remediation approach involving the microalga Chlamydomonas mexicana and activated sludge (ACS). At a 5 mg L-1 dye concentration, using C. mexicana and ACS alone, decolorization percentages of 39%-64% and 52%-54%, respectively, were obtained. In comparison, decolorization percentages of 75%-79% were obtained using a consortium of C. mexicana and ACS. The same trend was observed for the decolorization of dyes at higher concentrations, but the potential for decolorization was low. The toxic azo dyes adversely affect the growth of microalgae and at high concentration 50 mg L-1 the growth rate inhibited to 50-60% as compared to the control. The natural textile wastewater was also treated with the same pattern and got promising results of decolorization (90%). Moreover, the removal of BOD (82%), COD (72%), TN (64%), and TP (63%) was observed with the consortium. The HPLC and GC-MS confirm dye biotransformation, revealing the emergence of new peaks and the generation of multiple metabolites with more superficial structures, such as N-hydroxy-aniline, naphthalene-1-ol, and sodium hydroxy naphthalene. This analysis demonstrates the potential of the C. mexicana and ACS consortium for efficient, eco-friendly bioremediation of textile azo dyes.

Green biocatalyst for decolorization of azo dyes from industrial wastewater: Coriolopsis trogii 2SMKN laccase immobilized on recycled brewer's spent grain.

This study presents an innovative approach for the reuse and recycling of waste material, brewer's spent grain (BSG) for creating a novel green biocatalyst. The same BSG was utilized in several consecutive steps: initially, it served as a substrate for the cultivation and production of laccase by a novel isolated fungal strain, Coriolopsis trogii 2SMKN, then, it was reused as a carrier for laccase immobilization, aiding in the process of azo dye decolorization and finally, reused as recycled BSG for the second successful laccase immobilization for six guaiacol oxidation, contributing to a zero-waste strategy. The novel fungal strain produced laccase with a maximum activity of 171.4 U/g after 6 days of solid-state fermentation using BSG as a substrate. The obtained laccase exhibited excellent performance in the decolorization of azo dyes, both as a free and immobilized, at high temperatures, without addition of harmful mediators, achieving maximum decolorization efficiencies of 99.0%, 71.2%, and 61.0% for Orange G (OG), Congo Red, and Eriochrome Black T (EBT), respectively. The immobilized laccase on BSG was successfully reused across five cycles of azo dye decolorization process. Notably, new green biocatalyst outperformed commercial laccase from Aspergillus spp. in the decolorization of OG and EBT. GC-MS and LC-MS revealed azo-dye degradation products and decomposition pathway. This analysis was complemented by antimicrobial and phytotoxicity tests, which confirmed the non-toxic nature of the degradation products, indicating the potential for safe environmental disposal.