Study on free and entangled binary metal nanocatalysts for removal of 2,4,6-trichlorophenol in aqueous phase: a comparative study.

The present study highlights the comparative catalytic removal of 2,4,6-trichlorophenol (TCP) in the aqueous phase by binary nanoparticles in free as well as entangled forms. In brief, binary nanoparticles comprising Fe-Ni are prepared, characterized, and subsequently entangled in reduced graphene oxide (rGO) for better performances. Optimization studies on the mass of free and rGO-entangled binary nanoparticles with respect to TCP concentration and other environmental factors were carried out. Results suggested that free binary nanoparticles at 40 mg ml-1took 300 min to dechlorinate 600 ppm of TCP, whereas rGO-entangled Fe-Ni particles at the same mass took only 190 min to dechlorinate when the pH was maintained at near neutral. In addition, experiments on the reuse of the catalyst with respect to removal efficiency were carried out, and the results implied that, compared to free form, rGO-entangled nanoparticles exemplify more than 98% of removal efficacy even after 5 times of exposure to 600 ppm TCP concentration. The reduction in percentage removal was observed after the sixth exposure. A sequential dechlorination pattern was assessed and confirmed using high-performance liquid chromatography. Further, the phenol-enriched aqueous phase is exposed toBacillus licheniformisSL10, which degrades the phenol effectively within 24 h. In conclusion, the prepared binary nanoparticles, both in free as well as in rGO-entangled forms, effectively dechlorinate 2,4,6-TCP contaminations in the aqueous phase, but with differences in removal duration. Entanglement also makes it easier to reuse the catalyst. Furthermore, microbial phenol degradation allows the aqueous phase to be free of 2, 4, and 6-TCP contamination and allows for the reuse of treated water.

In vitro antibacterial activity of plumbagin isolated from Plumbago zeylanica L. against methicillin-resistant Staphylococcus aureus.

Plumbagin (5-hydroxy-2-methyl-1,4-napthoquinone) is a bicyclic naphthoquinone, found in three major plant families viz. Plumbaginaceae, Ebenceae and Droseraceae. The phytochemical is reported to exhibit various pharmacological properties. In this study, plumbagin isolated from Plumbago zeylanica L. was investigated for its in vitro activity against methicillin-resistant Staphylococcus aureus (MRSA). Against 100 MRSA isolates that included multi-drug-resistant phenotypes, plumbagin showed consistent activity with a narrow minimum inhibitory concentration (MIC) range of 4-8 µg ml-1 . The time-kill study revealed 99% kill of a reference MRSA strain, 8 h after exposure to plumbagin. In the combination MIC study using the reference MRSA strain, plumbagin showed synergistic effect with ciprofloxacin and piperacillin while additive or indifference effect with other commonly used antibiotics. The transmission electron micrograph of the reference MRSA strain treated with plumbagin confirmed cell wall and cytoplasmic changes. Our results demonstrated potent anti-MRSA activity of plumbagin which was not impacted by multi-drug resistance. This is a first ever study that evaluated in vitro anti-MRSA activity of plumbagin employing large number of MRSA isolates. The findings of this study support the need for the further investigation on this phytochemical agent for therapeutic application. SIGNIFICANCE AND IMPACT OF THE STUDY: This study revealed phytochemical plumbagin's potent and consistent in vitro antibacterial activity against clinically problematic methicillin-resistant Staphylococcus aureus (MRSA) including multi-drug-resistant (MDR) phenotypes. The study results support further research to assess the clinical scope of plumbagin.

Pre-treatment of extracellular water soluble pigmented secondary metabolites of marine imperfect fungus protects HDF cells from UVB induced oxidative stress.

The present study explores the UVB-induced oxidative stress protective efficacy of the pigmented fungal metabolite (identified as DHICA: 5,6-dihydroxyindole-2-carboxylic acid - a melanin precursor) using human dermal fibroblast (HDF) cells. DHICA is a water soluble pigment of the marine Aspergillus nidulans strain SG 28. Preliminary compatibility studies revealed 95% HDF cell viability with 600 µM concentration of DHICA. HDF cells were exposed to UVB irradiation with and without DHICA pre-treatment and the morphological, physiological and molecular level changes were observed accordingly. The results suggested that UVB exposure increases reactive oxygen species (ROS) generation and subsequent DNA damage in HDF cells, whereas DHICA pre-treatment appreciably reduces ROS generation and DNA damage. DHICA pre-treatment upregulates the antioxidant enzyme expressions and reduces the number of cells in the sub-Go/G1 phase. Gene expression analysis of TNF-α, IL-6, COX-2, NF-κB, Bax and Caspase 3 suggested that pre-treatment with DHICA downregulates the above-mentioned genes and simultaneously upregulates Bcl2 expression. In vivo experiments with BALB/c mice suggested that the topical application of DHICA protected mice skin from UVB-induced oxidative stress (which increases the epidermal thickness as evidenced in the skin sectioning). Thus, DHICA application protects the cells from UVB induced oxidative stress and may find applications in sunscreen cosmetic preparations.

A molecular technique to explore the relationship between Porphyromonas gingivalis and severity of chronic periodontitis: A clinical approach.

Relationship between clinical severities of periodontal disease and the expression of the associated pathogens serve as good indicators of real time disease activity and progression. A double blind study using Image J software carried out to assess the density of the amplified band for Porphyromonas gingivalis in periodontally healthy and disease subjects. Results on image densities of P. gingivalis showed a statistical significance (p < 0.005) between healthy and diseased subjects and also within the various groups of periodontal disease severity. Thus, assessment of relative gel image density can be a simple yet valuable tool to monitor real time periodontal disease activity.

Efficacy of free and encapsulated Bacillus lichenformis strain SL10 on degradation of phenol: A comparative study of degradation kinetics.

The present study exemplifies phenol degradation efficacy of the free and encapsulated bacterial isolate, explored the degradation kinetics and storage stability in detail. In brief, isolation, identification and phenol degradation potential of the bacterial made from wastewater treated sludge samples. The organism identified as B. licheniformis demonstrates phenol degradation at a concentration more than 1500 ppm. Optimization of environmental parameters reduces the time taken for degradation considerably. The organism has further been encapsulated using whey protein and the efficacy of encapsulated species suggested that encapsulation protects the cells from high concentration of phenol and at the same time expedite the degradation of the chosen pollutant at appreciable level. The encapsulated species effectively degrade 3000 ppm concentration of phenol within 96 h of incubation. Both pH and temperature stability observed in the encapsulated species suggests the effectiveness of the encapsulation. The encapsulated cells displayed storage stability for a four week period at 4 C and reusability up to three exposures. Degradation effected through intracellular catechol 2,3 dioxygenase. In conclusion, encapsulation of B. licheniformis (i) protects the cells from direct exposure to toxic pollutants; (ii) facilitates the field scale application and (iii) eliminate the practical difficulties in handling wet biomass in field application and assures the best possible way of remediating the phenol contaminated soil.

In vitro profiling of antimethicillin-resistant Staphylococcus aureus activity of thymoquinone against selected type and clinical strains.

UNLABELLED: This study explores antimethicillin-resistant Staphylococcus aureus (MRSA) activity of a bioactive phytochemical constituent, thymoquinone obtained from the medicinal herb, Nigella sativa Linn. Based on initial assessment on crude extract of seeds of Nigella sativa Linn, the pure active constituent was employed in the study. A total of 99 MRSA strains which comprised of 40 types and 59 clinical strains were selected for the study. Minimum inhibitory concentration (MIC), bactericidal activity, postantibiotic effect (PAE) and propensity to select resistant mutants were determined using standard protocols. Results revealed that thymoquinone exhibited MIC in the range of 8-16 µg ml(-1) and MIC90 of 16 µg ml(-1) against MRSA strains. It was bactericidal to MRSA by demonstrating >3 log kill. It showed a longer PAE of 3·2 ± 0·2 h. Upon exposure to high-density inoculum of MRSA, it did not select resistant mutants. Transmission electron microscopy of thymoquinone-treated MRSA showed no lysis but damage to cell wall and cell membrane which corroborated well with the salt tolerance and bacteriolysis assays. In conclusion, MIC90 , bactericidal property, longer PAE, absence of resistant mutant selection and damages in cell membrane and cell wall imply a promising anti-MRSA activity of thymoquinone. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first detailed report on anti-MRSA activity of thymoquinone. The assessment was made with both type and clinical strains. Thymoquinone may be a potential lead compound which can be further optimized to discover novel anti-MRSA agents.

Rejoining of cut wounds by engineered gelatin-keratin glue.

BACKGROUND: Rejoining of cut tissue ends of a critical site challenges clinicians. The toxicity, antigenicity, low adhesive strength, flexibility, swelling and cost of the currently employed glue demands an alternative. Engineered gelatin-keratin glue (EGK-glue) described in the present study was found to be suitable for wet tissue approximation. METHODS: EGK-glue was prepared by engineering gelatin with caffeic acid using EDC and conjugating with keratin by periodate oxidation. UV-visible, (1)H NMR and circular dichroism analyses followed by experiments on gelation time, rheology, gel adhesive strength (in vitro), wet tissue approximation (in vivo), H&E staining of tissue sections at scheduled time intervals and tensile strength of the healed skin were carried out to assess the effectiveness of the EGK-glue in comparison with fibrin glue and cyanoacrylate. RESULTS: Results of UV-visible, NMR and CD analyses confirmed the functionalization and secondary structural changes. Increasing concentration of keratin reduces the gelation time (<15s). Lap-shear test demonstrates the maximum adhesive strength of 16.6±1.2kPa. Results of hemocompatibility and cytocompatibility studies suggested the suitability of the glue for clinical applications. Tissue approximation property assessed using the incision wound model (Wistar strain) in comparison with cyanoacrylate and fibrin glue suggested, that EGK-glue explicitly accelerates the rejoining of tissue with a 1.86 fold increase in skin tensile strength after healing. CONCLUSIONS: Imparting quinone moiety to gelatin-keratin conjugates through caffeic acid and a weaker oxidizing agent provides an adhesive glue with appreciable strength, and hemocompatible, cytocompatible and biodegradable properties, which, rejoin the cut tissue ends effectively. GENERAL SIGNIFICANCE: EGK-glue obtained in the present study finds wide biomedical/clinical applications.

Preparation and characterization of malonic acid cross-linked chitosan and collagen 3D scaffolds: an approach on non-covalent interactions.

The present study emphasizes the influence of non-covalent interactions on the mechanical and thermal properties of the scaffolds of chitosan/collagen origin. Malonic acid (MA), a bifuncitonal diacid was chosen to offer non-covalent cross-linking. Three dimensional scaffolds was prepared using chitosan at 1.0% (w/v) and MA at 0.2% (w/v), similarly collagen 0.5% (w/v) and MA 0.2% (w/v) and characterized. Results on FT-IR, TGA, DSC, SEM and mechanical properties (tensile strength, stiffness, Young's modulus, etc.) assessment demonstrated the existence of non-covalent interaction between MA and chitosan/collagen, which offered flexibility and high strength to the scaffolds suitable for tissue engineering research. Studies using NIH 3T3 fibroblast cells suggested biocompatibility nature of the scaffolds. Docking simulation study further supports the intermolecular hydrogen bonding interactions between MA and chitosan/collagen.

Fibrous protein composite scaffolds (3D) for tissue regeneration: An in vitro study on skeletal muscle regeneration.

The present study explores the differentiation of myoblasts in bioengineered 3D composite scaffolds containing keratin and gelatin. Based on the composition and rheological properties three different scaffolds namely HM1, HM2 and HM3 were prepared, characterized and employed for the present study. The scaffolds were then subjected to C2C12 myoblasts differentiation under in vitro conditions as per the standard protocols. Results reveal a wide variation in the elastic modulus, water uptake and degradation rate of the scaffolds significantly impact the myogenesis processes. Composite scaffolds HM2 and HM3 ease the myogenesis compared to HM1, wherein, results in nil myogenesis. Among HM2 and HM3, accelerated myogenesis and the significant expression of myogenin mRNA levels along with extensive myotube development were observed in the HM3 scaffold. In conclusion, scaffolds modulus play a vital role in myogenesis and the observations of the present study provide a possible strategy for better skeletal muscle regeneration using composite scaffolds.

Bonding interactions and stability assessment of biopolymer material prepared using type III collagen of avian intestine and anionic polysaccharides.

The present study demonstrate bonding interactions between anionic polysaccharides, alginic acid (AA) and type III collagen extracted from avian intestine used for the preparation of thermally stable and biodegradable biopolymer material. Further the study describes, optimum conditions (pH, temperature and NaCl concentration) required for the formation of fibrils in type III collagen, assessment on degree of cross-linking, nature of bonding patterns, biocompatibility and biodegradability of the cross-linked biomaterial. Results revealed, the resultant biopolymer material exhibit high thermal stability with 5-6 fold increase in tensile strength compared to the plain AA and collagen materials. The degree of cross-linking was calculated as 75%. No cytotoxicity was observed for the cross-linked biopolymer material when tested with skin fibroblast cells and the material was biodegradable when treated with enzyme collagenase. With reference to bonding pattern analysis we found, AA cross-linked with type III collagen via (i) formation of covalent amide linkage between -COOH group of AA and ε-NH2 group of type-III collagen as well as (ii) intermolecular multiple hydrogen bonding between alginic acid -OH group with various amino acid functional group of type-III collagen. Comparisons were made with other cross-linking agents also. For better understanding of bonding pattern, bioinformatics analysis was carried out and discussed in detail. The results of the study emphasize, AA acts as a suitable natural cross-linker for the preparation of wound dressing biopolymer material using collagen. The tensile strength and the thermal stability further added value to the resultant biopolymer.

Preparation, characterization and cell response studies on bioconjugated 3D protein hydrogels with wide-range stiffness: An approach on cell therapy and cell storage.

The present study emphasizes the preparation and characterization of bioconjugated keratin-gelatin (KG) 3D hydrogels with wide-range stiffness to study cell response for cell therapy and cell storage applications. In brief, human hair keratin and bovine gelatin at different ratios bioconjugated using EDC/NHS provide five hydrogels (KG-1, KG-2.5, KG -5, KG-7.5 and KG-9) with modulus ranging from 0.9 ±â€¯0.1 to 10.9 ±â€¯0.4 kPa. Based on swelling, stability, porosity, and degradation parameters KG-5 and KG-9 are employed to assess the human dermal fibroblast (HDF) cell response, cell delivery and cell storage respectively. Characterization studies revealed the concentration of keratin determines the modulus/stiffness of the hydrogels, whereas gelatin concentration plays a vital role in porosity, swelling percentage, and degradation properties. HDF cell behaviour in the chosen hydrogels assessed based on cell adhesion, cell proliferation, PCNA expression, MTT assay, and DNA quantification. We observed the best cell behaviour in KG-5 hydrogels than in the KG-9 matrix. In cell storage and cell delivery studies, the KG-9 matrix displayed promising results. Thus, the present study concludes bioconjugated keratin-gelatin 3D hydrogel with modulus below 3.0 kPa facilitates the proliferation of HDFs, whereas matrix above 10 kPa modulus supports cell storage and cell recovery. The observations of the present study suggest the suitability of bioconjugated fibrous protein 3D hydrogel for cell therapy and cell storage.

Elucidation of 2, 4-Dichlorophenol degradation by Bacillus licheniformis strain SL10.

2,4-Dichlorophenol (2,4-DCP) is a priority pollutant according to US Environmental Protection Agency. Its use in various chemical industries and its presence in the effluent necessitate effective removal studies. The present study focuses on degradation of 2,4-DCP by phenol adapted bacteria Bacillus licheniformis strain SL10 (MTCC 25059) at a relatively faster rate. The organism exhibited tolerance to 150 ppm of 2,4-DCP and showed a linear relationship between the growth and substrate concentration (µmax 0.022/h) and the inhibitory concentration was 55.74 mg/L. The degradation efficiency of the organism was 74% under optimum conditions but increased to 97% when the growth medium containing nil sodium chloride. The degradation of 2,4-DCP was effected by the action of extracellular cocktail enzyme containing Catechol 2, 3 dioxygenase (C23DO), phenol hydroxylase and Catechol, 1,2 dioxygenase (C12DO). In vitro enzymatic degradation studies exhibit 98% degradation of 50 ppm of 2,4-DCP within 2 h. Analyses of degradation products infer that the chosen organism followed a meta-cleavage pathway while degrading 2,4-DCP. In conclusion, the bacteria Bacillus licheniformis strain SL10 finds potential application in the remediation of 2,4-DCP.

Dysregulation of miR-146a by periodontal pathogens: A risk for acute coronary syndrome.

BACKGROUND: Periodontitis is a polymicrobial, chronic inflammatory disease leading to loss of tooth-supporting structures. The bacteremia, endotoxemia, and systemic low-grade inflammation associate periodontitis with systemic illnesses such as diabetes mellitus and coronary artery disease. Periodontal pathogens have been detected from atheromatous plaque by amplification of the genetic material by using specific oligonucleotide primers in polymerase chain reaction. Though the association between periodontitis and cardiovascular diseases has been ascertained by systematic reviews and meta-analyses, its pathophysiology is not lucid. MicroRNAs are currently implicated in the regulation of many cellular processes including inflammation and may play a vital role in our understanding of this disease association. In this case-control study, we explored the role of the inflammatory microRNA, miR-146a, in acute coronary syndrome (ACS) subjects with and without chronic periodontitis (CP) and its regulation of the innate immune host response to periodontal pathogens. METHODS: Three groups each comprising 66 patients each, namely group 1 (ACS patients without CP), group 2 (ACS patients with CP) and group 3 (CP only) formed the study population. Subgingival plaque samples and serum samples were subjected to quantitative Polymerase Chain Reaction (qPCR) for detection of Porphyromonas gingivalis, a keystone pathogen and to assess the levels of circulating miR-146a and associated proinflammatory cytokines. RESULTS: miR-146a associated significantly in group 2 subjects with an odds ratio 1.434, 95% confidence interval 1.013-2.030, P < 0.042, and a predictive percentage of 83.3% and group 1 with a predictive percentage of 76.0.% The associated cytokines interleukin-6 (IL-6), tumor necrosis factor-α, and IL-1ß also showed an upregulation with statistical significance (P < 0.05). CONCLUSION: microRNA-146a is a key molecule associating periodontitis with acute coronary syndrome.

Synthesis, antibacterial and antifungal activities of some N-nitroso-2,6-diarylpiperidin-4-one semicarbazones and QSAR analysis.

A series of N-nitroso-2,6-diarylpiperidin-4-one semicarbazones and thiosemicarbazones were synthesized, characterized by IR, NMR and elemental analysis. All the compounds were screened for their antibacterial activity against Gram-positive bacteria Bacillus subtilis, Staphylococcus aureus and Gram-negative bacteria Escherichia coli and fungi Candida albicans. These compounds have showed moderate and very good antibacterial activity. Quantitative Structure Activity Relationship (QSAR) analysis was performed for these compounds by the application of Semiempirical calculations and molecular modeling. Different logP values were also evaluated to further the analysis.

Invivo studies on evaluation of potential toxicity of unspent tannins using albino rats (Rattusnorvegicus).

The present study emphasizes the effect of unspent tannins on liver, kidney and heart of albino rats. Oral administration of unspent tannins at three different concentrations was made for a period of seven days. Carbon tetrachloride served as positive control. Tissues were removed carefully followed by sacrifice and were subjected to sectioning and H&E staining. Histopathological examination of the sections showed, major tissue damage with the highest concentration of tannins (1500mg/kg body weight) irrespective of their nature and source, followed by moderate damage with the 1000mg/kgbw and zero damage with 500mg/kgbw. However, complete damage was observed with the tissues of positive control group. Lipid peroxidase assay using post-mitochondrial supernatant of liver, kidney and heart showed appreciable levels of malondialdehyde release at higher concentrations of tannins.

Marine fungal DHICA as a UVB protectant: Assessment under in vitro and in vivo conditions.

The present study explores UVB protective role of a melanin precursor namely DHICA (5,6- Dihydroxyindole-2-carboxylic acid) expressed by the marine imperfect fungus Aspergillus nidulans. In brief, A. nidulans grown in a modified growth medium for the period of 5 days at 25 °C under shaking conditions and the extracellular medium free from fungal biomass used for the extraction of DHICA. The extracted DHICA further exposed to partial purification and subjected to UVB protection studies using HaCaT cells and Balb/c mice independently. DHICA obtained in the present study found soluble in water. Experiments on HaCaT cell compatibility revealed nil cell death up to 500 µM concentration of DHICA. UVB protection studies under in vitro conditions emphasizes DHICA significantly protect HaCaT cells from UVB exposure by quenching the generated ROS, reducing cell apoptosis, maintain the cellular integrity and sequentially down regulating the LPO (Lipid peroxidation) and up-regulating the antioxidant enzyme (SOD (Superoxide Dismutase), Catalase, GPx (Glutathione peroxidase)) respectively. Further, experiments on cell cycle arrest analysis, gelatin zymography, and western blot analysis on COX-2 and TNF-alpha, IHC (Immunohistochemistry) on apoptotic markers (Bax, Bcl2) substantiate the protective role of DHICA. Furthermore, in vivo studies on BALB/c mice carried out and compared with the sunscreen cream with sun protective factor (SPF) of 20. Analysis of skin sections of experimental samples revealed that an appreciable reduction in the epidermal thickness of the skin samples of mice pre-exposed to DHICA followed by UVB exposure compared to UVB exposure alone. RT-PCR results on various inflammatory apoptotic markers also suggested that DHICA has UVB protective potential. The observations made in the present study explore the possible application of DHICA alone as a sun-protective agent for skin care.

Preparation, characterization and reusability efficacy of amine-functionalized graphene oxide-polyphenol oxidase complex for removal of phenol from aqueous phase.

The present study explores the preparation, characterization and reusability efficacy of an amine-functionalized graphene oxide and polyphenol oxidase complex for the removal of phenol from aqueous phase. In brief, graphene oxide (GO) is synthesized according to modified Hummer's method using graphite powder and functionalized with amine using the Bucherer's method (GO-NH2). Partially purified polyphenol oxidase (PP-PPO) enzyme extracted from Solanum tuberosum is used for the preparation of the complex. The resultant GO-NH2-(PP-PPO) complex is used for the phenol degradation studies. The samples of GO, GO-NH2, and GO-NH2-(PP-PPO) complex are characterized using various instrumental techniques. Spectral UV data and FTIR and XRD diffraction patterns confirm the amine functionalization on GO. Raman spectrum, SEM micrograph and thermogravimetric (TG) analyses authenticate the linked enzyme on GO-NH2. GO-NH2-(PP-PPO) complex demonstrates >90% enzyme stability at all the studied temperatures (4 °C, -20 °C, RT and 37 °C). Phenol degradation studies show >99% removal of 1000 ppm of phenol within 5 hours from the start of the experiment at the optimized pH of 5.0 and temperature of 30 °C, as inferred from HPLC analysis. Catechol and hydroquinone compounds are identified as intermediates during the removal of phenol. Furthermore, studies on the reuse of GO-NH2-(PP-PPO) complex suggest that the complex can be used effectively for the removal of phenol up to maximum 7 cycles. In conclusion, the observations made in the present study show that the complex containing amine-functionalized graphene oxide and phenoloxidase is effective for the removal of phenol with appreciable reusability.

Exploring the UVB-protective efficacy of melanin precursor extracted from marine imperfect fungus: Featuring characterization and application studies under in vitro conditions.

The present study explores the production, characterization, and application of a potentially stable melanin precursor from marine imperfect non-spore-forming Aspergillus nidulans sp. strain SG 28. Growth of the culture in artificial seawater with galactose and monosodium glutamate, pH at 7.2-7.5, and temperature at 35 ± 0.5 °C exhibits pigment production with the yield of 0.700-0.800 g/L. The characterization studies revealed that the pigment is orange reddish pink in color, soluble in water, insoluble in both polar and non-polar organic solvents, and decolorized when exposed to H2O2, KMnO4, and K2Cr2O7. UV-visible spectrum exhibits maximum absorption peak at 330 nm and mild shoulders at 400 and 500 nm. The pigment displayed both antioxidant and reducing power properties when exposed with ABTS and ferricyanide, respectively. The sun protection factor of the pigment was determined as 9.9. The cytocompatibility of the obtained pigment studied using HaCaT cells revealed that the cells are viable up to 500 µM. Experiments on UVB protection of the pigment using HaCat cells demonstrated the appreciable protective effect by reducing the ROS generation upon UVB exposure. In conclusion, the pigment obtained from the marine imperfect fungus showed structural similarity with DHICA which is confirmed by LC-MS. The presence of metal ions in the growth medium mediates the reaction to proceed towards DHICA formation. The SPF analysis, antioxidant property, and the UVB protection studies authenticate the potential use of pigment for skin care.

Surface active gold nanoparticles biosynthesis by new approach for bionanocatalytic activity.

In the present day, nanotechnology is one of the most promising leading scientific and potentials areas in modern key technology development toward to the humankind. The synthesis of noble metal nanoparticles (NPs) is an expanding research area due to the possible applications for the development of bio-medical applications. Eco-friendly approach for the biosynthesis of gold nanoparticles (AuNPs) using the aqueous extract from Ruellia tuberosa and Phyllanthus acidus (leaf and twig) for the first time. Surface active AuNPs were characterized by UV-Vis spectroscopy, FTIR (Fourier transform infrared) spectroscopy, DSC (differential scanning colorimetry), DLS (dynamic light scattering) and environmental SEM (scanning electron microscope) analysis at room temperature (RT). Enhanced surface plasmon resonance (SPR) absorbance UV visible optical spectra were detected in the range of 552, 548, 558 and 536 nm. SEM and DLS (transmission mode) analysis confirmed the morphology of the nanoparticles to be spherical with the average size in the range of 88.37, 94.31, 82.23 and 81.36 nm. Further they have enhanced the enzyme activity on α-amylase, cellulase, and xylanase. The results suggest that the phyto-fabricated AuNPs from R. tuberosa and P. acidus is simple, less expensive, eco-friendly, green synthesis and also can be exploited for the potential future industrial and bio-medical applications.

Biodegradability of leathers through anaerobic pathway.

Leather processing generates huge amounts of both solid and liquid wastes. The management of solid wastes, especially tanned leather waste, is a challenging problem faced by tanners. Hence, studies on biodegradability of leather become imperative. In this present work, biodegradability of untanned, chrome tanned and vegetable tanned leather under anaerobic conditions has been addressed. Two different sources of anaerobes have been used for this purpose. The effect of detanning as a pretreatment method before subjecting the leather to biodegradation has also been studied. It has been found that vegetable tanned leather leads to more gas production than chrome tanned leather. Mixed anaerobic isolates when employed as an inoculum are able to degrade the soluble organics of vegetable tanned material and thus exhibit an increased level of gas production during the initial days, compared to the results of the treatments that received the anaerobic sludge. With chrome tanned materials, there was not much change in the volume of the gas produced from the two different sources. It has been found that detanning tends to improve the biodegradability of both types of leathers.