Characterization, catalytic, and recyclability studies of nano-sized spherical palladium particles synthesized using aqueous poly-extract (turmeric, neem, and tulasi).

Green synthesis of noble metal nanoparticles (NPs) has gained immense significance compared to other metal ions owing to their unique properties. Among them, palladium 'Pd' has been in the spotlight for its stable and superior catalytic activity. This work focuses on the synthesis of Pd NPs using the combined aqueous extract (poly-extract) of turmeric (rhizome), neem (leaves), and tulasi (leaves). The bio-synthesized Pd NPs were characterized to study its physicochemical and morphological features using several analytical techniques. Role of Pd NPs as nano-catalysts in the degradation of dyes (1 mg/2 mL stock solution) was evaluated in the presence of a strong reducing agent (sodium borohydride; SBH). In the presence of Pd NPs and SBH, maximum reduction of methylene blue (MB), methyl orange (MO), and rhodamine-B (Rh-B) dyes was observed under 20nullmin (96.55 ± 2.11%), 36nullmin (96.96 ± 2.24%), and 27nullmin (98.12 ± 1.33%), with degradation rate of 0.1789 ± 0.0273 min-1, 0.0926 ± 0.0102 min-1, and 0.1557 ± 0.0200 min-1, respectively. In combination of dyes (MB + MO + Rh-B), maximum degradation was observed under 50nullmin (95.49 ± 2.56%) with degradation rate of 0.0694 ± 0.0087 min-1. It was observed that degradation was following pseudo-first order reaction kinetics. Furthermore, Pd NPs showed good recyclability up to cycle 5 (72.88 ± 2.32%), cycle 9 (69.11 ± 2.19%) and cycle 6 (66.21 ± 2.72%) for MB, MO and Rh-B dyes, respectively. Whereas, up to cycle 4 (74.67 ± 0.66%) during combination of dyes. As Pd NPs showed good recyclability, they can be used for several cycles thus influencing the overall economics of the process.

Effect of size on physicochemical, antibacterial, and catalytic properties of Neolamarckia cadamba (burflower-tree) synthesized silver/silver chloride nanoparticles.

Aqueous extract of Neolamarchia cadamba leaves were used in the synthesis of silver/silver chloride nanoparticles (Ag/AgCl NPs). Further they were separated based on their using step-wise centrifugation approach at 09,000, 12,000, and 15,000 rpm. Thus obtained NPs were characterized for their physicochemical features. NPs showed maximum absorbance at 455 nm, 415 nm, and 402 nm. All the NPs were found to be crystalline in nature with average crystallite size (nm) of 58.31, 23.43, and 09.56. Particle size distribution (nm) of NPs was observed to 435.43, 276.75, and 105.49, Surface charge (-mV) of NPs was observed to be 14.59, 23.90, and 32.17. Ag/AgCl NPs-rpm@15,000 showed antibacterial activity against Escherichia coli, coagulase-negative Staphylococci, and Staphylococcus aureus with zone of inhibition (mm) of 16.65, 13.69, and 14.02 at 50 µg per well, respectively. Ag/AgCl NPs-rpm@15,000 showed excellent catalytic activity in degradation of methyl red, methylene blue, rhodamine-B, and methyl orange dyes in the presence of sodium borohydride under 4, 6, 5, and 4 min with pseudo-first order rate constant (min-1) of 0.981 (96.4%), 0.666 (97.1%), 0.905 (98.1%), and 1.032 (96.6%), respectively. Furthermore, Ag/AgCl NPs-rpm@15,000 showed good catalytic efficiency even under different dye combinations. Total combination was degraded under 18 min.

Role of metagenomics in prospecting novel endoglucanases, accentuating functional metagenomics approach in second-generation biofuel production: a review.

As the fossil fuel reserves are depleting rapidly, there is a need for alternate fuels to meet the day to day mounting energy demands. As fossil fuel started depleting, a quest for alternate forms of fuel was initiated and biofuel is one of its promising outcomes. First-generation biofuels are made from edible sources like vegetable oils, starch, and sugars. Second-generation biofuels (SGB) are derived from lignocellulosic crops and the third-generation involves algae for biofuel production. Technical challenges in the production of SGB are hampering its commercialization. Advanced molecular technologies like metagenomics can help in the discovery of novel lignocellulosic biomass-degrading enzymes for commercialization and industrial production of SGB. This review discusses the metagenomic outcomes to enlighten the importance of unexplored habitats for novel cellulolytic gene mining. It also emphasizes the potential of different metagenomic approaches to explore the uncultivable cellulose-degrading microbiome as well as cellulolytic enzymes associated with them. This review also includes effective pre-treatment technology and consolidated bioprocessing for efficient biofuel production.

Microbial cancer therapeutics: A promising approach.

The success of conventional cancer therapeutics is hindered by associated dreadful side-effects of antibiotic resistance and the dearth of antitumor drugs' selectivity and specificity. Hence, the conceptual evolution of anti-cancerous therapeutic agents that selectively target cancer cells without impacting the healthy cells or tissues, has led to a new wave of scientific interest in microbial-derived bioactive molecules. Such strategic solutions may pave the way to surmount the shortcomings of conventional therapies and raise the potential and hope for the cure of wide range of cancer in a selective manner. This review aims to provide a comprehensive summary of anti-carcinogenic properties and underlying mechanisms of bioactive molecules of microbial origin, and discuss the current challenges and effective therapeutic application of combinatorial strategies to attain minimal systemic side-effects.

Biogenic synthesis of novel platinum-palladium bimetallic nanoparticles from aqueous Annona muricata leaf extract for catalytic activity.

This work reports the fast and effective bio-fabrication of novel platinum-palladium bimetallic nanoparticles (Pt-Pd BNPs) along with their counterparts Pt and Pd monometallic NPs (MNPs) through aqueous Annona muricata leaf extract. The bio-fabrication of the NPs was achieved within 2 h at 100 °C and pH 7 which was established by the occurrence of dark brown color for Pt MNPs and black color for Pd MNPs and Pt-Pd BNPs. NPs were evaluated for their catalytic activity in the reduction of methyl orange (MO), rhodamine-B (rh-B), and methylene blue (MB) textile dyes in presence of sodium borohydride as a reducing agent. Pt-Pd (1:3) BNPs showed higher MO dye degradation (96.84 ± 2.05% in 50 min) followed by Pd MNPs (97.07 ± 1.46% in 60 min), Pt-Pd (3:1) BNPs (97.34 ± 1.17% in 70 min) and Pt-Pd (1:1) BNPs (98.12 ± 1.04% in 80 min). Pd MNPs showed significant catalytic activity in the reduction of rh-B dye by 97.27 ± 1.14% in 12 min followed by Pt-Pd (3:1) BNPs (96.76 ± 2.17% in 18 min), Pt-Pd (1:3) BNPs (96.53 ± 1.97% in 33 min) and Pt-Pd (1:1) BNPs (97.11 ± 2.09% in 39 min). Pt-Pd (1:3) BNPs also showed higher MB dye degradation (96.95 ± 1.57% in 40 min) followed by Pd MNPs (96.22 ± 2.36% in 55 min), Pt-Pd (3:1) BNPs (97.29 ± 1.22% in 75 min) and Pt-Pd (1:1) BNPs (96.45 ± 2.19% in 105 min). However, Pt MNPs showed no catalytic activity. Standard disc diffusion method was used to evaluate the NPs toxicity towards Escherichia coli and Staphylococcus aureus, which showed no inhibitory zones. NPs showed less toxicity compared to potassium dichromate (control) against Artemia nauplii. Among the NPs studied, Pt-Pd (1:1) BNPs showed less toxicity with 100% mortality only at 100 µg/mL concentration followed by Pt MNPs (≥ 80 µg/mL), Pt-Pd (1:3) BNPs (≥ 60 µg/mL), Pt-Pd (3:1) BNPs (≥ 60 µg/mL) and Pd MNPs (≥ 40 µg/mL) after 72 h exposure. These evaluations support the application of bio-fabricated Pt-Pd BNPs as nano-catalysts in textile dyes degradation. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02935-0.

Novel buffalo rumen metagenome derived acidic cellulase Cel-3.1 cloning, characterization, and its application in saccharifying rice straw and corncob biomass.

Lignocellulosic biomass (LCB) is a prominent option for second-generation biofuels production. Cellulase hydrolyses cellulose, a component of LCB by attacking the ß-1,4-glycosidic bonds, thus liberating mono, di, and oligosaccharides, which subsequently, can be converted to biofuel. In this study, a novel cellulase (Cel-3.1) of 1593 bp which encodes a 530 amino acid protein was identified from buffalo rumen metagenomic fosmid library, and functional expression was achieved through transformation into Escherichia coli. The molecular weight was estimated as 58 kDa on SDS-PAGE. Cel-3.1 belongs to glycosyl hydrolase family-5 (GH-5) and is predicted to have 14 α-helices and 15 ß-strands. The optimal temperature and pH for Cel-3.1 were experimentally determined as 5.0 and 50 °C respectively. The synergistic effect of Ca2+ with K+ ions improved Cel-3.1 activity significantly (25%) and 1% Polyethylene Glycol (PEG-400), 1% ß-mercaptoethanol enhanced the relative activity Cel-3.1 by 31.68%, 12.03% respectively. Further, the enzymatic (Cel-3.1) hydrolysis of pretreated rice straw and corncob released 13.41 ± 0.26 mg/mL and 15.04 ± 0.08 mg/mL reducing sugars respectively. High Performance Liquid Chromatography (HPLC), Scanning Electron Microscope (SEM), and Fourier Transformation Infrared spectroscopy (FTIR) analysis revealed the capability of Cel-3.1 for the breakdown and hydrolysis of both rice straw and corncob to generate various fermentable sugars.

Reducing sugars production from corncobs: a comparative study of chemical and biotechnological methods.

Two commonly used chemical pretreatment processes, sulphuric acid, and sodium hydroxide, were tested to provide comparative performance data. A connection between solid to liquid ratio (S/L) and sugars released was observed with an increase in S/L ratio between 0.02 and 0.2. Enzymatic digestibility of 1 M of NaOH-pretreated corncobs were released 210.7 mg ml(-1) of sugars. Further, compared with different concentrations of acid pretreatments at 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, and 0.5 M concentrations, sodium hydroxide pretreatment of corncob substantially increased accessibility and digestibility of cellulose. Another additional observation made was whole-cell and crude enzymatic hydrolysis of different concentrations of acid and NaOH (0.05, 0.1, 0.25 M)-treated materials released lower amount of sugars compared with the sugars released (310.9 mg ml(-1)) with whole-cell hydrolysis of 1 M of NaOH-treated corncobs. NaOH-pretreated corncobs contained higher content of sugars and which is more suitable for production of reducing sugars.

Role of signaling pathways in mesenchymal stem cell differentiation.

Mesenchymal Stem Cells (MSCs) are self-renewing cells with ability to differentiate into organized, functional network of cells. In recent past research in developing clinical applications for MSCs has increased significantly. MSCs exhibit multi potential proliferation, and are capable of differentiating into cartilage, bone, neuronal cells and adipocytes, etc. Signaling pathways, transcription factors and growth factors modulate the differentiation of MSCs into different cell lineages. Besides, physical factors may regulate the molecular differentiation of stem cells. The main theme of this paper is to review the signaling pathways related to bone morphogenetic proteins (BMPs), epidermal growth factors (EGF), transforming growth factors (TGF), wingless type MMTV integration site (wnt) proteins, fibroblastic growth factor (FGF), and transcriptional regulating factors significance in the MSCs differentiation.

Significance of biotic factors in mesenchymal stem cell fate in regenerative medicine.

Stem and progenitor cell research is a complex and exciting field which promises curative discoveries in numerous areas including cancer, diabetes, and regenerative medicine. Use of biotic factors or growth factors has played an essential role in the development of stem cell research. These biologically active components have been administered into stem cells either to improve or maintain the stem cell proliferation, or to encourage controlled differentiation into more defined cell types. Small molecules such as 6-Bromoindirubin-3´-oxime (BIO), cardiogenol-C, etc can help stem cell research by controlling or influencing the regulatory changes in a controlled manner and to help understand the mechanisms during stem cell differentiation. Extra cellular matrix (ECM) is another significant biotic factor, which mediates cell and tissue behavior by influencing cell-matrix interactions. Thus, in this review we would like to emphasize significance of various growth factors in stem cell research.

Influence of dilute acid and alkali pretreatment on reducing sugar production from corncobs by crude enzymatic method: a comparative study.

In the present study, two commonly used catalysts in chemical pretreatment, sulfuric acid and sodium hydroxide, were tested to evaluate the effect of solid-to-liquid ratio on pretreatment and enzymatic hydrolysis. Solid to liquid ratio (S/L) was influential on sugars released with an increase in the S/L ratio between 0.03 and 0.2. Enzymatic digestibility of 0.25 M H2SO4 pretreated corncobs were released more sugars (415.12 mg/mL); whereas, corncobs pretreated with NaOH released 350.12 mg/mL of reducing sugars at S/L 0.05. Further, in comparison with NaOH pretreated corncobs, acid treated material substantially increased the accessibility and digestibility of cellulose during crude enzymatic hydrolysis (28.96 FPU) and released 398.95 mg/mL reducing sugars.

Optimization of amorphadiene production in engineered yeast by response surface methodology.

Isoprenoids are among the most diverse bioactive compounds synthesized by biological systems. The superiority of these compounds has expanded their utility from pharmaceutical to fragrances, including biofuel industries. In the present study, an engineered yeast strain Saccharomyces cerevisiae (YCF-AD1) was optimized for production of Amorpha-4, 11-diene, a precursor of anti-malarial drug using response surface methodology. The effect of four critical parameters such as KH2PO4, methionine, pH and temperature were evaluated both qualitatively and quantitatively and further optimized for enhanced amorphadiene production by using a central composite design and model validation. The "goodness of fit" of the regression equation and model fit (R2) of 0.9896 demonstrate this study to be an effective model. Further, this model will be used to validate theoretically and experimentally at the higher level of amorphadiene production with the combination of the optimized values of KH2PO4 (4.0), methionine (1.49), pH (5.4) and temperature (33 °C).

Combination of ERG9 Repression and Enzyme Fusion Technology for Improved Production of Amorphadiene in Saccharomyces cerevisiae.

The yeast strain (Saccharomyces cerevisiae) MTCC 3157 was selected for combinatorial biosynthesis of plant sesquiterpene amorpha-4,11-diene. Our main objective was to overproduce amorpha 4-11-diene, which is a key precursor molecule of artemisinin (antimalarial drug) produced naturally in plant Artemisia annua through mevalonate pathway. Farnesyl diphosphate (FPP) is a common intermediate metabolite of a variety of compounds in the mevalonate pathway of yeast and leads to the production of ergosterols, dolichol and ubiquinone, and so forth. In our studies, FPP converted to amorphadiene (AD) by expressing heterologous amorphadiene synthase (ADS) in yeast. First, ERG9 (squalane synthase) promoter of yeast was replaced with repressible methionine (MET3) promoter by using bipartite gene fusion method. Further to overcome the loss of the intermediate FPP through competitive pathways in yeast, fusion protein technology was adopted and farnesyldiphosphate synthase (FPPS) of yeast has been coupled with amorphadiene synthase (ADS) of plant origin (Artemisia annua L.) where amorphadiene production was improved by 2-fold (11.2 mg/L) and 4-fold (25.02 mg/L) in yeast strains YCF-002 and YCF-005 compared with control strain YCF-AD (5.5 mg/L), respectively.

Physical and degradation properties of PLGA scaffolds fabricated by salt fusion technique.

Tissue engineering scaffolds require a controlled pore size and interconnected pore structures to support the host tissue growth. In the present study, three dimensional (3D) hybrid scaffolds of poly lactic acid (PLA) and poly glycolic acid (PGA) were fabricated using solvent casting/particulate leaching. In this case, partially fused NaCl particles were used as porogen (200-300µ) to improve the overall porosity (≥90%) and internal texture of scaffolds. Differential scanning calorimeter (DSC) analysis of these porous scaffolds revealed a gradual reduction in glass transition temperature (Tg) (from 48°C to 42.5°C) with increase in hydrophilic PGA content. The potential applications of these scaffolds as implants were further tested for their biocompatibility and biodegradability in four simulated body fluid (SBF) types in vitro. Whereas, simulated body fluid (SBF) Type1 with the optimal amount of HCO3 (-) ions was found to be more appropriate and sensible for testing the bioactivity of scaffolds. Among three combinations of polymer scaffolds, sample B with a ratio of 75:25 of PLA: PGA showed greater stability in body fluids (pH 7.2) with an optimum degradation rate (9% to 12% approx). X-ray diffractogram also confirmed a thin layer of hydroxyapatite deposition over sample B with all SBF types in vitro.

Study on osteoblast like behavior of umbilical cord blood cells on various combinations of PLGA scaffolds prepared by salt fusion.

The osteogenic potential of mesenchymal stem cells (MSCs) from umbilical cord blood (UCB) on porous poly lactide-co-glycolide (PLGA) scaffolds have been reported to differentially support osteogenic differentiation based on polymer composition (80:20, 75:25 and 70:30 percent of PLA: PGA, respectively). Along with polymer composition; fused NaCl crystal matrix prior to solvent casting improves the porosity and pore interconnectivity in 3D scaffolds, which has significant impact on cell proliferation. FTIR and XRD studies of PLGA scaffolds also verified the intermolecular interactions, phase distribution and crystallinity in scaffolds. Among three scaffold combinations, sample B (75:25) has showed maximum porosity with optimum water uptake/retention abilities. Impact of polymer composition and porosity on cell proliferation was investigated through MTT assay, where sample B was observed to be supporting better cell proliferation,due to its internal structure. The above results were further confirmed by ALP and Col-I gene expression studies using RT-PCR. Immuno fluorescent studies also revealed the extracellular filamentous actin organization over the scaffolds, where cell adhesion and proliferation was found to be higher with increase in PGA content, which is a hydrophilic polymer.

Enhanced proliferation and osteogenic differentiation of human umbilical cord blood stem cells by L-ascorbic acid, in vitro.

The multilineage potentiality of cord blood stem cells has been experimentally proven in a number of cell based therapies. Umbilical cord blood (UCB) derived mesenchymal stem cells (MSCs), on prolonged exposure with Lascorbic acid have been successfully differentiated in to osteoblasts (bone forming cells) without altering the phenotype of the cells. In this case study, the role of L-ascorbic acid on collagen biosynthesis and mineral deposition in MSCs has been assessed, which are ultimately matured in to an insoluble extra cellular matrix (ECM), giving mechanical strength to the bone cells. Moreover, up to specific concentration of L-ascorbic acid (250µM), proliferation as well as differentiation potential of the cells remains unaltered. Further increase in concentrations of L-ascorbic acid (500 µM) reduced the cell proliferation and subsequently leads to morphological changes in the cultures. This may be due to an immature antioxidant defense system, which can be overcome by treating the cell cultures with antioxidants. Our final results conclude that Lascorbic acid has positive effect on the ostogenic differentiation of cord blood stem cells, and the concentration of ascorbic acid is vital in cell proliferation and differentiation.

Simultaneous pretreatment and sacchariffication of rice husk by Phanerochete chrysosporium for improved production of reducing sugars.

Phanerochete chrysosporium, the white-rot fungus, (a best source for lignolytic enzymes system) was used in the biological pretreatment of rice husk for reducing sugars production. Usually reducing sugar production through biochemical process involves two steps: solid state fermentation (SSF) of fungal pretreatment for delignification, subsequently pretreated biomass subjected to enzymatic hydrolysis. During the fungal pretreatment of rice husk for reducing sugar production along with cellulase and xylanse, the activities of lignin degradation-related enzymes such as lignin peroxidases (LiP), GLOX (glyoxidase), and aryl alcohol oxidases (AAO), were observed. The fungal pretreated rice husk produced highest (895.9 mg/ml/2g of rise husk) reducing sugars on 18th day of fungal treatment. This method may be good alternative to avoid operational costs associated with washing and the removal of inhibitors during the conventional pretreatment methods.

Mixing of acid and base pretreated corncobs for improved production of reducing sugars and reduction in water use during neutralization.

Pretreatment of biomass for bioethanol production makes it necessary to use large amounts of water for removing inhibitors and neutralization. In order to reduce water usage, separate batches of corncobs were hydrolyzed in 1M NaOH and 0.05 M H(2)SO(4), respectively, and the hydrolysis products were mixed to achieve a pH of 7. This approach lowered water usage by 10-fold compared with neutralization by distilled and recycling wash water. Mixing of the pretreated biomasses (121°C, 20 min) increased release of reducing sugars during enzymatic hydrolysis with cellulases (38.49 FPU(IU)) produced by Phanerochaete chrysosporium NCIM 1106 by 2- and 15-fold compared with the sugars released from the unmixed NaOH- and H(2)SO(4)-treated corncobs, respectively. Enzymatic hydrolysis (EH, cell free extract) of the mixed material released 395.15 mg/ml of sugars during 48 h, slightly less than what was achieved by microbial hydrolysis (whole cell hydrolysis), 424.50mg after 120 h.

Development of petri net-based dynamic model for improved production of farnesyl pyrophosphate by integrating mevalonate and methylerythritol phosphate pathways in yeast.

In this case study, we designed a farnesyl pyrophosphate (FPP) biosynthetic network using hybrid functional Petri net with extension (HFPNe) which is derived from traditional Petri net theory and allows easy modeling with graphical approach of various types of entities in the networks together. Our main objective is to improve the production of FPP in yeast, which is further converted to amorphadiene (AD), a precursor of artemisinin (antimalarial drug). Natively, mevalonate (MEV) pathway is present in yeast. Methyl erythritol phosphate pathways (MEP) are present only in higher plant plastids and eubacteria, but not present in yeast. IPP and DAMP are common isomeric intermediate in these two pathways, which immediately yields FPP. By integrating these two pathways in yeast, we augmented the FPP synthesis approximately two folds higher (431.16 U/pt) than in MEV pathway alone (259.91 U/pt) by using HFPNe technique. Further enhanced FPP levels converted to AD by amorphadiene synthase gene yielding 436.5 U/pt of AD which approximately two folds higher compared to the AD (258.5 U/pt) synthesized by MEV pathway exclusively. Simulation and validation processes performed using these models are reliable with identified biological information and data.