Directional co-immobilization of artificial multimeric-enzyme complexes as a robust biocatalyst for biosynthesis curcumin glucosides and regeneration of UDP-glucose.

Site-directed protein immobilization allows the homogeneous orientation of proteins while maintaining high activity, which is advantageous for various applications. In this study, the use of SpyCatcher/SpyTag technology and magnetic nickel ferrite (NiFe2O4 NPs) nanoparticles were used to prepare a site-directed immobilization of BsUGT2m from Bacillus subtilis and AtSUSm from Arabidopsis thaliana for enhancing curcumin glucoside production with UDP-glucose regeneration from sucrose and UDP. The immobilization of self-assembled multienzyme complex (MESAs) enzymes were characterized for immobilization parameters and stability, including thermal, pH, storage stability, and reusability. The immobilized MESAs exhibited a 2.5-fold reduction in UDP consumption, enhancing catalytic efficiency. Moreover, the immobilized MESAs demonstrated high storage and temperature stability over 21 days at 4 °C and 25 °C, outperforming their free counterparts. Reusability assays showed that the immobilized MESAs retained 78.7 % activity after 10 cycles. Utilizing fed-batch technology, the cumulative titer of curcumin 4'-O-ß-D-glucoside reached 6.51 mM (3.57 g/L) and 9.45 mM (5.18 g/L) for free AtSUSm/BsUGT2m and immobilized MESAs, respectively, over 12 h. This study demonstrates the efficiency of magnetic nickel ferrite nanoparticles in co-immobilizing enzymes, enhancing biocatalysts' catalytic efficiency, reusability, and stability.

A comprehensive review on biological funnel mechanism in lignin valorization: Pathways and enzyme dynamics.

Lignin, a significant byproduct of the paper and pulp industry, is attracting interest due to its potential utilization in biomaterial-based sectors and biofuel production. Investigating biological methods for converting lignin into valuable products is crucial for effective utilization and has recently gained growing attention. Several microorganisms effectively decomposed low molecular weight lignins, transforming them into intermediate compounds via upper and lower metabolic pathways. This review focuses on assessing bacterial metabolic pathways involved in the breakdown of lignin into aromatic compounds and their subsequent utilization by different bacteria through various metabolic pathways. Understanding these pathways is essential for developing efficient synthetic metabolic systems to valorize lignin and obtain valuable industrial aromatic chemicals. The concept of "biological funneling," which involves examining key enzymes, their interactions, and the complex metabolic pathways associated with lignin conversion, is crucial in lignin valorization. By manipulating lignin metabolic pathways and utilizing biological routes, many aromatic compounds can be synthesized within cellular factories. Although there is insufficient evidence regarding the complete metabolism of polyaromatic hydrocarbons by particular microorganisms, understanding lignin-degrading enzymes, regulatory mechanisms, and interactions among various enzyme systems is essential for optimizing lignin valorization. This review highlights recent advancements in lignin valorization, bio-funneling, multi-omics, and analytical characterization approaches for aromatic utilization. It provides up-to-date information and insights into the latest research findings and technological innovations. The review offers valuable insights into the future potential of biological routes for lignin valorization.

Immediate health risk: Concentration of heavy metals in contaminated freshwater fishes from the river channel of Turag-Tongi-Balu.

The consumption of contaminated finfish from the polluted river channel of Turag-Tongi-Balu, Kamarpara site, Dhaka poses significant health hazards to humans. We used mass spectrometry on chemically digested liquid samples from five fish species from Turag-Tongi-Balu to estimate the concentrations of 10 elements (Cr, Mn, Ni, Cu, Zn, As, Se, Cd, Fe, and Pb). Except M. vittatus, the mean concentrations of Cd, Mn, Pb, and Se exceeded the Food Safety Guideline (FSG) value in all fish species. Among the species studied, L. rohita, C. punctata, C. batrachus, H. fossilis, and M. vittatus exhibited higher Mn concentrations surpassing the FSG threshold, thus elevating the non-carcinogenic risk across all species. There were statistically significant differences (p < .05) in the mean concentrations of heavy metals among fish species. The Target Hazard Quotient (THQ) value of Mn poses a significant non-carcinogenic risk to human health, while the hazard of other metals is negligible. Except for M. vittus, the Hazard Index value (HI ≥ 1) revealed the risk that all metals exceed the limit and pose a threat to human health. Cd, As, and Ni metals pose a significant carcinogenic risk to human health from the consumption of fish samples, which is a particularly alarming target cancer risk (TCR). In conclusion, regular dietary consumption of fish from this polluted ecosystem of the Turag-Tongi-Balu River channel's Kamarpara site poses a significant health risk and is indicated as cancer. This study emphasizes the significance of monitoring heavy metal contamination in finfish and minimizing the risk to human health with effective measures.

Ectoine Globally Hypomethylates DNA in Skin Cells and Suppresses Cancer Proliferation.

Epigenetic modifications, mainly aberrant DNA methylation, have been shown to silence the expression of genes involved in epigenetic diseases, including cancer suppression genes. Almost all conventional cancer therapeutic agents, such as the DNA hypomethylation drug 5-aza-2-deoxycytidine, have insurmountable side effects. To investigate the role of the well-known DNA protectant (ectoine) in skin cell DNA methylation and cancer cell proliferation, comprehensive methylome sequence analysis, 5-methyl cytosine (5mC) analysis, proliferation and tumorigenicity assays, and DNA epigenetic modifications-related gene analysis were performed. The results showed that extended ectoine treatment globally hypomethylated DNA in skin cells, especially in the CpG island (CGIs) element, and 5mC percentage was significantly reduced. Moreover, ectoine mildly inhibited skin cell proliferation and did not induce tumorigenicity in HaCaT cells injected into athymic nude mice. HaCaT cells treated with ectoine for 24 weeks modulated the mRNA expression levels of Dnmt1, Dnmt3a, Dnmt3b, Dnmt3l, Hdac1, Hdac2, Kdm3a, Mettl3, Mettl14, Snrpn, and Mest. Overall, ectoine mildly demethylates DNA in skin cells, modulates the expression of epigenetic modification-related genes, and reduces cell proliferation. This evidence suggests that ectoine is a potential anti-aging agent that prevents DNA hypermethylation and subsequently activates cancer-suppressing genes.

Evaluation of a dye-decolorizing peroxidase from Comamonas serinivorans for lignin valorization potentials.

Although dye-decolourising peroxidases (DyPs) are well-known for lignin degradation, a comprehensive understanding of their mechanism remains unclear. Therefore, studying the mechanism of lignin degradation by DyPs is necessary for industrial applications and enzyme engineering. In this study, a dye-decolourising peroxidase (CsDyP) gene from C. serinivorans was heterologously expressed and studied for its lignin degradation potential. Molecular docking analysis predicted the binding of 2, 2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), veratryl alcohol (VA), 2, 6-dimethylphenol (2, 6- DMP), guaiacol (GUA), and lignin to the substrate-binding pocket of CsDyP. Evaluation of the enzymatic properties showed that CsDyP requires pH 4.0 and 30 °C for optimal activity and has a high affinity for ABTS. In addition, CsDyP is stable over a wide range of temperatures and pH and can tolerate 5.0 mM organic solvents. Low NaCl concentrations promoted CsDyP activity. Further, CsDyP significantly reduced the chemical oxygen demand decolourised alkali lignin (AL) and milled wood lignin (MWL). CsDyP targets the ß-O-4, CO, and CC bonds linking lignin's G, S, and H units to depolymerize and produce aromatic compounds. Overall, this study delivers valuable insights into the lignin degradation mechanism of CsDyP, which can benefit its industrial applications and lignin valorization.

Antioxidant and Anticancer Assessment and Phytochemical Investigation of Three Varieties of Date Fruits.

Date palm (Phoenix dactylifera L.) fruits contain high concentrations of phenolic compounds, particularly flavonoids and other micronutrients, which impact human health due to their potent antioxidant, anti-inflammatory, and anticancer characteristics. In the present study, the effect of ethyl acetate, hydroethanol, hydromethanol, and aqueous extract from three date palm varieties (i.e., Ajwa, Siwi, and Sukkari) on phytochemical profiles and antioxidant and anticancer activities was investigated. Fruit extracts were screened for their antioxidant activity using the DPPH· method. Phenolic constituents were quantified and identified using HPLC-DAD. Extracts (ethyl acetate, hydroethanol, and hydromethanol) were assessed for cytotoxicity on nine human cancer cell lines, i.e., MG-63, HCT116, MCF7, MDA-MB-231, HEPG2, HUH7, A549, H460, and HFB4, using the sulphorhodamine-B (SRB) assay. Results showed that the ethyl acetate extract of the Sukkari fruits has the greatest antioxidant potential with an IC50 value of 132.4 ± 0.3 µg·mL-1, while the aqueous extract of Ajwa date fruits exhibited the lowest antioxidant effect with an IC50 value of 867.1 ± 0.3 µg·mL-1. The extracts exhibited potent to moderate anticancer activities against the investigated cancer cell line in a source-dependent manner. Methanol extract of Siwi fruits exhibited the most potent anticancer activity (IC50 = 99 ± 1.6 µg·mL-1), followed by the same extract of Sukkari fruits with an IC50 value of 119 ± 3.5 µg·mL-1 against the cell line of human breast cancer (MDA-MB-231). Additionally, principal component analysis (PCA) was investigated to determine the relationship among the investigated traits and treatments. Our findings reveal that date palm fruit-derived extracts are excellent sources of biologically active constituents and substantiate their potential use in new anticancer strategies from natural resources.

Highly Efficient Biosynthesis of Glycyrrhetinic Acid Glucosides by Coupling of Microbial Glycosyltransferase to Plant Sucrose Synthase.

Glycyrrhetinic acid (GA) is a principal bioactive pentacyclic triterpenoid from Glycyrrhiza uralensis. Uridine diphosphate-dependent glycosyltransferases (UGTs) have been widely used to catalyze glycosylation of diverse nature products for the development of potential therapeutic compounds. In this study, we have characterized a UGT109A3 from Bacillus subtilis, which can glycosylate both the free C3 hydroxyl and C30 carboxyl groups of GA to yield a unique 3, 30-O-ß-D-diglucoside-GA. By coupling the microbial UGT109A3 to plant sucrose synthase (SUS), GA-diglucoside could be biosynthesized in an efficient and economical way. With a fed-batch glycosylation, a large scale of GA-diglucoside (6.26 mM, 4.98 g/L in 8 h) could be enzymatically transformed from GA. The obtained GA-diglucoside showed a significant water solubility improvement of around 3.4 × 103 fold compared with that of the parent GA (29 µM). Moreover, it also exhibited dose-dependent cytotoxicity toward human colon carcinoma Caco-2 cell line according to MTT assay, having an IC50 at 160 µM. This study not only establishes efficient platform for producing GA-glucosides, but is also valuable for developing further the biosynthesis of other complex glycosylated natural products.

Ordered Coimmobilization of Multimeric Enzyme Arrays with Enhanced Biocatalytic Cascade Performance.

Multiple enzyme coimmobilizations mimicking nature cascade enzymatic pathways have potential applications in diverse fields. We have developed a strategy for orderly coimmobilizing multienzymes by combining hierarchically self-assembled multimeric enzymes with specifically abundant polyhistidine tag affinity-mediated immobilization. Using this strategy, an ordered coimmobilization of the glycosyltransferase UGT51 mutant and sucrose synthase was constructed to realize the regeneration of costly sugar donor UDP-glucose that was used in the biosynthesis of the rare ginsenoside Rh2. The ordered coimmobilization array not only significantly boosted the immobilization and catalysis efficiency but also improved UDP-glucose regeneration, storage stability, and reusability compared to those of random coimmobilization and free enzyme-assembly systems. This study provides a great promise for fabricating enzyme arrays and highlights the synergistic benefits of nanocomplexes in enhancing biocatalytic cascade performance.

In vivo genotoxicity assessment of sunset yellow and sodium benzoate in female rats.

The use of additives in different food products is growing up. It has attracted the attention towards the relation between the mutagenic potential of human diseases and food additives. Sunset yellow (SY) and sodium benzoate (NaB) are used as colorant and food additives worldwide. In the present study, genotoxic effects of different combinations of SY and NaB were assessed in vivo in female rats. Different combinations of SY and NaB were dissolved in water and administered daily to six animals groups for 12 weeks. Group 1 (control) received water, Group 2 received 5 mg/kg body weight (bw) SY plus 10 mg/kg bw NaB, group 3 received 5 mg/kg SY plus 100 mg/kg NaB, group 4 received 50 mg SY plus 100 mg/kg NaB, group 5 received 50 mg/kg SY plus 10 mg/kg NaB, group 6 received 200 mg/kg SY plus 750 mg/kg NaB, and group 7 received 20 mg/kg SY plus 75 mg/kg NaB. Genotoxicity investigations (Chromosomal aberration of bone marrow cells, Comet assay and DNA profile of liver cells) were carried out at the end of the experiment. Administration of 200 mg/kg SY plus 750 mg/kg NaB (group 6) induced the highest abnormalities percentage (1.5%) and showed structural abnormalities including end-to-end association, fragmentation, chromatid break, ring chromosome, and centric fusion break of chromosomes. Different combinations of SY and NaB induced an increase in the frequency of tailed nuclei (DNA damage) in liver cells. A concentration-dependent distinct DNA smear pattern was observed in the DNA isolated from liver cells of animals administered SY and NaB. In addition, administration of SY plus NaB resulted in an abnormal distribution of serum proteins. The results showed that the SY plus NaB could have genotoxic potential. With the increase applications of food additives, this study reported important data about screening the potential impacts.