Nanomaterials as adsorbents for As(III) and As(V) removal from water: A review.

Freshwater demand will rise in the next couple of decades, with an increase in worldwide population growth and industrial development. The development activities, on one side, have increased the freshwater demand. However, the ground water has been degraded. Among the various organic and inorganic contaminants, arsenic is one of the most toxic elements. Arsenic contamination in ground waters is a major issue worldwide, especially in South and Southeast Asia. Various methods have been applied to provide a remedy to arsenic contamination, including adsorption, ion exchange, oxidation, coagulation-precipitation and filtration, and membrane filtration. Out of these methods, adsorption of As(III)/As(V) using nanomaterials and biopolymers has been used on a wide scale. The present review focuses on recently used nanomaterials and biopolymer composites for As(III)/As(V) sorptive removal. As(III)/As(V) adsorption mechanisms have been explored for various sorbents. The impacts of environmental factors such as pH and co-existing ions on As(III)/As(V) removal, have been discussed. Comparison of various nanosorbents and biopolymer composites for As(III)/As(V) adsorption and regeneration of exhausted materials has been included. Overall, this review will be useful to understand the sorption mechanisms involved in As(III)/As(V) removal by nanomaterials and biopolymer composites and their comparative sorption performances.

Clean approach for chromium removal in aqueous environments and role of nanomaterials in bioremediation: Present research and future perspective.

Chromium is an insidious ecological pollutant that is of huge value for its toxicity. The existing ecological objective to lower the heights of toxic materials in marine systems and to stimulate the existing water to recycle after suitable treatment of wastewater. Chromium is a hazard element that appears in discharges of numerous industries that must be diminished to accomplish the goals. Nearly all of the findings described in the literature related to the usage of various materials such as fungal, algal, bacterial biomass, and nanomaterials for chromium adsorption. The current work evaluates the findings of research commenced in the preceding on the use of a variety of adsorbents to decrease chromium concentrations in contaminated waters. This review article focuses on the issue of chromium contamination, its chemistry, causes, consequences, biological agent remediation techniques, and the detailed process of chromium detoxification in microbial cells. It also lists a description of the in situ and ex situ chromium bioremediation methods used. This can help design more effective Cr(VI) removal methods, thus bridging the difference between laboratory discoveries and industrial chromium remediation applications.

Ultrasound-assisted synthesis of mixed calcium magnesium oxide (CaMgO2) nanoflakes for photocatalytic degradation of methylene blue.

In the present study, mixed calcium magnesium oxide (CaMgO2) nanoflakes were synthesized using an ultrasound-assisted co-precipitation method. The physicochemical, structural and functional properties and elemental composition of the nanoflakes had been characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), High-resolution transmission electron microscopy (HR-TEM), Fourier Transform Infrared spectroscopy (FTIR), UV-VIS spectroscopy, X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Moreover, the photocatalytic actions of the nanoflakes were evaluated by the removal rates of methylene blue (MB) and p-nitrophenol (4-NP) under UV irradiation at room temperature. SEM-EDS studies revealed that the nanoflakes consisted of mixed oxide such as magnesium oxide (MgO) and calcium oxide (CaO) particles. The size of the nanoflakes was found to be in the range of 10-30 nm and the average size was 25 nm as confirmed by HR-TEM analysis. XRD revealed that the standard crystal size was calculated to be 25 nm. The synthesized nanoflakes had a strong photocatalytic activity for methylene blue (MB) and p-nitrophenol (4-NP) degradation in the presence of H2O2 under UV light irradiation within 60 min and 30 min, respectively. Hence, the present study proposes that the CaMgO2 nanoflakes can be employed for the removal of dyes from wastewater.

Green synthesis of cobalt-oxide nanoparticle using jumbo Muscadine (Vitis rotundifolia): Characterization and photo-catalytic activity of acid Blue-74.

In the recent years, plant and microbial extract based nanoparticles (NPs) have become a sophisticated technology serving as an alternative strategy for the purpose of developing materials functionalized by structural diversity and enhanced energy efficiencies. Cobalt oxide nanoparticles (GCoO-NPs) have wide applications in several sectors due to their high resistance to corrosion as well as oxidation, ecofriendly nature, cost effectiveness and nontoxic potential. Plant based particles are credible alternatives as they reduce the burden of complicated and laborious protocols of physiochemical reliance. In this study, GCoO-NPs were synthesized using the grape Jumbo Muscadine (Vitis rotundifolia) using co-precipitation. The synthesized GCoO-NPs were characterized by UV-Vis spectrophotometer, Fourier transform infrared spectroscopy (FTIR), Powder X-ray diffraction (PXRD) and Scanning electron microscopy (SEM). The photocatalytic activity of the GCoO-NPs was estimated by the degradation of Acid Blue-74 (AB-74) dye and the complete degradation of 98% was accomplished at the reaction time of 150 min at pH 10 and 60 mg/100 mL concentration. The outcomes of this study indicated the excellent performance of the GCoO-NPs on par with some of the earlier findings and this can be an appealing aspirant of extreme potential to be employed as a catalyst alternative to the conventional wastewater treatment methods.

Enzyme therapy: a forerunner in catalyzing a healthy society?

INTRODUCTION: The use of enzymes in various industries has been prevalent for centuries. However, their potency as therapeutics remained latent until the late 1950 s, when scientists finally realized the gold mine they were sitting on. Enzyme therapy has seen rapid development over the past few decades and has been widely used for the therapy of myriad diseases, including lysosomal storage disorders, cancer, Alzheimer's disease, irritable bowel syndrome, exocrine pancreatic insufficiency, and hyperuricemia. Enzymes are also used for wound healing, the treatment of microbial infections, and gene therapy. AREAS COVERED: This is a comprehensive review of the therapeutic use of enzymes that can act as a guidepost for researchers and academicians and presents a general overview of the developments in enzyme therapy over the years, along with updates on recent advancements in enzyme therapy research. EXPERT OPINION: Although enzyme therapy is immensely beneficial and induces little auxiliary damage, it has several drawbacks, ranging from high cost, low stability, low production, and hyperimmune responses to the failure to cure a variety of the problems associated with a disease. Further fine-tuning and additional clinical efficacy studies are required to establish enzyme therapy as a forerunner to catalyzing a healthy society.

Biosynthesized silver nanoparticles using Bacillus amyloliquefaciens; Application for cytotoxicity effect on A549 cell line and photocatalytic degradation of p-nitrophenol.

The present study reports the biosynthesis of silver nanoparticles (AgNPs) using Bacillus amyloliquefaciens MSR5. The cellfree supernatant of B. amyloliquefaciens acted as a stabilizing agent for the synthesis of AgNPs. The synthesized AgNPs were characterized using UV-vis spectrophotometer, PXRD, FTIR, SEM-EDX, DLS, and TEM. TEM image showed the spherical shape of the biosynthesized AgNPs and it was found to be 20-40 nm in range. In this study, the AgNPs were prepared by ultrasonic irradiation. The stability of the AgNPs was found to be -33.4 mV using zeta potential. The catalytic 4-nitrophenol (4-NP) degradation by AgNPs was examined under solar irradiation and furthermore, the effects of several degradation parameters were studied. The biosynthesized AgNPs exhibited a strong chemocatalytic action with a comprehensive degradation (98%) of 4-NP to 4-aminophenol (4-AP) using NaBH4 within 15 min. In addition, MTT assay was performed to evaluate the cytotoxicity of the biosynthesized AgNPs (10 - 200 µg). The results have shown that the AgNPs exhibited significant activity on A549 cells, which was dosedependent. The study elucidates the AgNPs synthesized using cellfree culture supernatant can be used for the elimination of hazardous pollutants from wastewater.

Recombinant l-Asparaginase II from Lactobacillus casei subsp. casei ATCC 393 and Its Anticancer Activity.

l-asparaginases from bacterial origin are employed extensively in leukemic treatment and food industry. The present study focuses on the characterization of the recombinant l-asparaginase II from Lactobacillus casei subsp. casei ATCC 393 cloned into Escherichia coli expression system and purified using Ni-NTA chromatography. The recombinant l-asparaginase as a monomer had a molecular weight of 35 kDa. The enzyme was active from 10 to 80 °C with the optimum at 40 °C. The enzyme retained its activity at 28 °C and 37 °C up to 24 h. The enzyme had optimum pH of 6 and retained 50% activity till 18 h. The Km of the recombinant enzyme was 0.01235 mM and Vmax 1.576 mM/min. The half life of recombinant l-asparaginase II in human serum was 44 h and trypsin was for 15 min. The LC-MS/MS analysis revealed the molecular weight of 35,050 and pI of 5.64. The secondary structure prediction using CD spectroscopy for the recombinant enzyme showed 33.5% α-helix, 66.5% turn and 0% ß sheets. The cytotoxicity of the recombinant enzyme was analysed against MOLT 3, Jurkat E6.1 and K-562 with the IC 50 value of 30, 62.5 and 50 µg/ml.

A computational method to characterize the missense mutations in the catalytic domain of GAA protein causing Pompe disease.

Pompe disease is an autosomal recessive lysosomal storage disease caused by acid α-glucosidase (GAA) deficiency, resulting in intralysosomal accumulation of glycogen, including cardiac, skeletal, and smooth muscle cells. The GAA gene is located on chromosome 17 (17q25.3), the GAA protein consists of 952 amino acids; of which 378 amino acids (347-726) falls within the catalytic domain of the protein and comprises of active sites (518 and 521) and binding sites (404, 600, 616, and 674). In this study, we used several computational tools to classify the missense mutations in the catalytic domain of GAA for their pathogenicity and stability. Eight missense mutations (R437C, G478R, N573H, Y575S, G605D, V642D, L705P, and L712P) were predicted to be pathogenic and destabilizing to the protein structure. These mutations were further subjected to phenotyping analysis using SNPeffect 4.0 to predict the chaperone binding sites and structural stability of the protein. The mutations R437C and G478R were found to compromise the chaperone-binding activity with GAA. Molecular docking analysis revealed that the G478R mutation to be more significant and hinders binding to the DNJ (Miglustat) compared with the R437C. Further molecular dynamic analysis for the two mutations demonstrated that the G478R mutation was acquired higher deviation, fluctuation, and lower compactness with decreased intramolecular hydrogen bonds compared to the mutant R437C. These data are expected to serve as a platform for drug design against Pompe disease and will serve as an ultimate tool for variant classification and interpretations.

Kinetic studies on exploring lactose hydrolysis potential of ß galactosidase extracted from Lactobacillus plantarum HF571129.

A novel intracellular ß-galactosidases produced by Lactobacillus plantarum HF571129, isolated from an Indian traditional fermented milk product curd was purified and characterized. The ß-galactosidases is a hetrodimer with a molecular weight of 60 kDa (larger subunit) and 42 kDa (smaller subunit), as estimated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme was purified 7.23 fold by ultrasonication, ultrafiltration and gel filtration chromatography with an overall recovery of 30.41 %. The optimum temperature for hydrolysis of its preferred substrates, o-nitrophenyl- ß-D-galactopyranoside (ONPG) and lactose, are 50 °C (both), and optimum pH for these reactions is 6.5 and 7.5, respectively. The ß-galactosidases showed higher affinity for ONPG (Km, 6.644 mM) as compared to lactose (Km, 23.28 mM). Galactose, the end product of lactose hydrolysis was found to be inhibited (47 %). The enzyme activity was drastically altered by the metal ion chelators EDTA, representing that this enzyme is a metalloenzyme. The enzyme was activated to a larger extent by Mg(2+) (73 % at 1 mM), while inhibited at higher concentrations of Na(+) (54 % at 100 mM), K(+) (16 % at 100 mM) and urea (16 % at 100 mM). The thermal stability study indicated an inactivation energy of Ed = 171.37 kJ mol(-1). Thermodynamic parameters such as ∆H, ∆S and ∆G, were determined as a function of temperature. About 88 % of lactose was hydrolyzed at room temperature within 1 h. The study suggested that this enzyme showed its obvious superiority in the industrial lactose conversion process.

Immobilization of ß-galactosidase from Lactobacillus plantarum HF571129 on ZnO nanoparticles: characterization and lactose hydrolysis.

ß-Galactosidase from Lactobacillus plantarum HF571129 was immobilized on zinc oxide nanoparticles (ZnO NPs) using adsorption and cross-linking technique. Immobilized ß-galactosidase showed broad-spectrum pH optima at pH 5-7.5 and temperature 50-60 °C. Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM) showed that ß-galactosidase successfully immobilized onto supports. Due to the limited diffusion of high molecular weight substrate, K m of immobilized enzyme slightly increased from 6.64 to 10.22 mM, while V max increased from 147.5 to 192.4 µmol min(-1) mg(-1) as compared to the soluble enzyme. The cross-linked adsorbed enzyme retained 90 % activity after 1-month storage, while the native enzyme showed only 74 % activity under similar incubation conditions. The cross-linked ß-galactosidase showed activity until the seventh cycle and maintained 88.02 % activity even after the third cycle. The activation energy of thermal deactivation from immobilized biocatalyst was 24.33 kcal/mol with a half-life of 130.78 min at 35 °C. The rate of lactose hydrolysis for batch and packed bed was found to be 0.023 and 0.04 min(-1).

Studies on heavy metal removal efficiency and antibacterial activity of chitosan prepared from shrimp shell waste.

Chitosan, a natural biopolymer composed of a linear polysaccharide of α (1-4)-linked 2-amino 2-deoxy ß-D glucopyranose was synthesized by deacetylation of chitin, which is one of the major structural elements, that forms the exoskeleton of crustacean shrimps. The present study was undertaken to prepare chitosan from shrimp shell waste. The physiochemical properties like degree of deacetylation (74.82 %), ash content (2.28 %), and yield (17 %) of prepared chitosan indicated that that shrimp shell waste is a good source of chitosan. Functional property like water-binding capacity (1,136 %) and fat-binding capacity (772 %) of prepared chitosan are in total concurrence with commercially available chitosan. Fourier Transform Infra Red spectrum shows characteristic peaks of amide at 1,629.85 cm-1 and hydroxyl at 3,450.65 cm-1. X-ray diffraction pattern was employed to characterize the crystallinity of prepared chitosan and it indicated two characteristic peaks at 10° and 20° at (2θ). Scanning electron microscopy analysis was performed to determine the surface morphology. Heavy metal removal efficiency of prepared chitosan was determined using atomic absorption spectrophotometer. Chitosan was found to be effective in removing metal ions Cu(II), Zn(II), Fe(II) and Cr(IV) from industrial effluent. Antibacterial activity of the prepared chitosan was also determined against Xanthomonas sp. isolated from leaves affected with citrus canker.