An Overview of Recent Advancements in Microbial Polyhydroxyalkanoates (PHA) Production from Dark Fermentation Acidogenic Effluents: A Path to an Integrated Bio-Refinery.

Global energy consumption has been increasing in tandem with economic growth motivating researchers to focus on renewable energy sources. Dark fermentative hydrogen synthesis utilizing various biomass resources is a promising, less costly, and less energy-intensive bioprocess relative to other biohydrogen production routes. The generated acidogenic dark fermentative effluent [e.g., volatile fatty acids (VFAs)] has potential as a reliable and sustainable carbon substrate for polyhydroxyalkanoate (PHA) synthesis. PHA, an important alternative to petrochemical based polymers has attracted interest recently, owing to its biodegradability and biocompatibility. This review illustrates methods for the conversion of acidogenic effluents (VFAs), such as acetate, butyrate, propionate, lactate, valerate, and mixtures of VFAs, into the value-added compound PHA. In addition, the review provides a comprehensive update on research progress of VFAs to PHA conversion and related enhancement techniques including optimization of operational parameters, fermentation strategies, and genetic engineering approaches. Finally, potential bottlenecks and future directions for the conversion of VFAs to PHA are outlined. This review offers insights to researchers on an integrated biorefinery route for sustainable and cost-effective bioplastics production.

α-Cellulose Fibers of Paper-Waste Origin Surface-Modified with Fe3O4 and Thiolated-Chitosan for Efficacious Immobilization of Laccase.

The utilization of waste-paper-biomass for extraction of important α-cellulose biopolymer, and modification of extracted α-cellulose for application in enzyme immobilization can be extremely vital for green circular bio-economy. Thus, in this study, α-cellulose fibers were super-magnetized (Fe3O4), grafted with chitosan (CTNs), and thiol (-SH) modified for laccase immobilization. The developed material was characterized by high-resolution transmission electron microscopy (HR-TEM), HR-TEM energy dispersive X-ray spectroscopy (HR-TEM-EDS), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) analyses. Laccase immobilized on α-Cellulose-Fe3O4-CTNs (α-Cellulose-Fe3O4-CTNs-Laccase) gave significant activity recovery (99.16%) and laccase loading potential (169.36 mg/g). The α-Cellulose-Fe3O4-CTNs-Laccase displayed excellent stabilities for temperature, pH, and storage time. The α-Cellulose-Fe3O4-CTNs-Laccase applied in repeated cycles shown remarkable consistency of activity retention for 10 cycles. After the 10th cycle, α-Cellulose-Fe3O4-CTNs possessed 80.65% relative activity. Furthermore, α-Cellulose-Fe3O4-CTNs-Laccase shown excellent degradation of pharmaceutical contaminant sulfamethoxazole (SMX). The SMX degradation by α-Cellulose-Fe3O4-CTNs-Laccase was found optimum at incubation time (20 h), pH (3), temperatures (30 °C), and shaking conditions (200 rpm). Finally, α-Cellulose-Fe3O4-CTNs-Laccase gave repeated degradation of SMX. Thus, this study presents a novel, waste-derived, highly capable, and super-magnetic nanocomposite for enzyme immobilization applications.

A comprehensive overview and recent advances on polyhydroxyalkanoates (PHA) production using various organic waste streams.

Polyhydroxyalkanoates (PHA) are appealing as an important alternative to replace synthetic plastics owing to its comparable physicochemical properties to that of synthetic plastics, and biodegradable and biocompatible nature. This review gives an inclusive overview of the current research activities dealing with PHA production by utilizing different waste fluxes generated from food, milk and sugar processing industries. Valorization of these waste fluxes makes the process cost effective and practically applicable. Recent advances in the approaches adopted for waste treatment, fermentation strategies, and genetic engineering can give insights to the researchers for future direction of waste to bioplastics production. Lastly, synthesis and application of PHA-nanocomposites, research and development challenges, future perspectives for sustainable and cost-effective PHB production are also discussed. In addition, the review addresses the useful information about the opportunities and confines associated with the sustainable PHA production using different waste streams and their evaluation for commercial implementation within a biorefinery.

Efficient Biofilms Eradication by Enzymatic-Cocktail of Pancreatic Protease Type-I and Bacterial α-Amylase.

Removal of biofilms is extremely pivotal in environmental and medicinal fields. Therefore, reporting the new-enzymes and their combinations for dispersal of infectious biofilms can be extremely critical. Herein, for the first time, we accessed the enzyme "protease from bovine pancreas type-I (PtI)" for anti-biofilm properties. We further investigated the anti-biofilm potential of PtI in combination with α-amylase from Bacillus sp. (αA). PtI showed a very significant biofilm inhibition effect (86.5%, 88.4%, and 67%) and biofilm prevention effect (66%, 64%, and 70%), against the E. coli, S. aureus, and MRSA, respectively. However, the new enzyme combination (Ec-PtI+αA) exhibited biofilm inhibition effect (78%, 90%, and 93%) and a biofilm prevention effect (44%, 51%, and 77%) against E. coli, S. aureus, and MRSA, respectively. The studied enzymes were found not to be anti-bacterial against the E. coli, S. aureus, and MRSA. In summary, the PtI exhibited significant anti-biofilm effects against S. aureus, MRSA, and E. coli. Ec-PtI+αA exhibited enhancement of the anti-biofilm effects against S. aureus and MRSA biofilms. Therefore, this study revealed that this Ec-PtI+αA enzymatic system can be extremely vital for the treatment of biofilm complications resulting from E. coli, S. aureus, and MRSA.

Chitosan-Grafted Halloysite Nanotubes-Fe3O4 Composite for Laccase-Immobilization and Sulfamethoxazole-Degradation.

A surface-engineered nano-support for enzyme laccase-immobilization was designed by grafting the surface of halloysite nanotubes (HNTs) with Fe3O4 nanoparticles and chitosan. Herein, HNTs were magnetized (HNTs-M) by a cost-effective reduction-precipitation method. The synthesized HNTs-M were grafted with 0.25%, 0.5%, 1%, and 2% chitosan (HNTs-M-chitosan), respectively. Synthesized HNTs-M-chitosan (0.25%), HNTs-M-chitosan (0.5%), HNTs-M-chitosan (1%) and HNTs-M-chitosan (2%) were linked with glutaraldehyde (GTA) for laccase immobilization. Among these formulations, HNTs-M-chitosan (1%) exhibited the highest laccase immobilization with 95.13% activity recovery and 100.12 mg/g of laccase loading. The optimized material was characterized thoroughly by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), X-ray powder diffraction (XRD), thermal gravimetric analysis (TGA), and vibrating sample magnetometer (VSM) analysis. The immobilized laccase (HNTs-M-chitosan (1%)-GTA-Laccase) exhibited higher pH, temperature, and storage stabilities. The HNTs-M-chitosan (1%)-GTA-Laccase possesses excellent reusability capabilities. At the end of 10 cycles of the reusability experiment, HNTs-M-chitosan (1%)-GTA-Laccase retained 59.88% of its initial activity. The immobilized laccase was utilized for redox-mediated degradation of sulfamethoxazole (SMX), resulting in 41%, 59%, and 62% degradation of SMX in the presence of 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), guaiacol (GUA), and syringaldehyde (SA), respectively. Repeated SMX degradation (57.10% after the sixth cycle) confirmed the potential of HNTs-M-chitosan (1%)-GTA-Laccase for environmental pollutant degradation. Thus, we successfully designed chitosan-based, rapidly separable super-magnetic nanotubes for efficacious enhancement of laccase biocatalysis, which can be applied as nano-supports for other enzymes.

Supermagnetic Sugarcane Bagasse Hydrochar for Enhanced Osteoconduction in Human Adipose Tissue-Derived Mesenchymal Stem Cells.

Hydrothermally carbonized sugarcane bagasse (SCB) has exceptional surface properties. Looking at the huge amount of SCB produced, its biocompatible nature, cheap-cost for carbonization, and its easy functionalization can give impeccable nano-biomaterials for tissue engineering applications. Herein, sugarcane bagasse was converted into hydrochar (SCB-H) by hydrothermal carbonation. The SCB-H produced was further modified with iron oxide (Fe3O4) nanoparticles (denoted as SCB-H@Fe3O4). Facile synthesized nano-bio-composites were characterized by SEM, HR-TEM, XRD, FT-IR, XPS, TGA, and VSM analysis. Bare Fe3O4 nanoparticles (NPs), SCB-H, and SCB-H@Fe3O4 were tested for cytocompatibility and osteoconduction enhancement of human adipose tissue-derived mesenchymal stem cells (hADMSCs). The results confirmed the cytocompatible and nontoxic nature of SCB-H@Fe3O4. SCB-H did not show enhancement in osteoconduction, whilst on the other hand, Fe3O4 NPs exhibited a 0.5-fold increase in the osteoconduction of hADMSCs. However, SCB-H@Fe3O4 demonstrated an excellent enhancement in osteoconduction of a 3-fold increase over the control, and a 2.5-fold increase over the bare Fe3O4 NPs. Correspondingly, the expression patterns assessment of osteoconduction marker genes (ALP, OCN, and RUNX2) confirmed the osteoconductive enhancement by SCB-H@Fe3O4. In the proposed mechanism, the surface of SCB-H@Fe3O4 might provide a unique topology, and anchoring to receptors of hADMSCs leads to accelerated osteogenesis. In conclusion, agriculture waste-derived sustainable materials like "SCB-H@Fe3O44" can be potentially applied in highly valued medicinal applications of stem cell differentiation.

Thiolation of Chitosan Loaded over Super-Magnetic Halloysite Nanotubes for Enhanced Laccase Immobilization.

This study focuses on the development of a nanosupport based on halloysite nanotubes (HNTs), Fe3O4 nanoparticles (NPs), and thiolated chitosan (CTs) for laccase immobilization. First, HNTs were modified with Fe3O4 NPs (HNTs-Fe3O4) by the coprecipitation method. Then, the HNTs-Fe3O4 surface was tuned with the CTs (HNTs-Fe3O4-CTs) by a simple refluxing method. Finally, the HNTs- Fe3O4-CTs surface was thiolated (-SH) (denoted as; HNTs- Fe3O4-CTs-SH) by using the reactive NHS-ester reaction. The thiol-modified HNTs (HNTs- Fe3O4-CTs-SH) were characterized by FE-SEM, HR-TEM, XPS, XRD, FT-IR, and VSM analyses. The HNTs-Fe3O4-CTs-SH was applied for the laccase immobilization. It gave excellent immobilization of laccase with 100% activity recovery and 144 mg/g laccase loading capacity. The immobilized laccase on HNTs-Fe3O4-CTs-SH (HNTs-Fe3O4-CTs-S-S-Laccase) exhibited enhanced biocatalytic performance with improved thermal, storage, and pH stabilities. HNTs-Fe3O4-CTs-S-S-Laccase gave outstanding repeated cycle capability, at the end of the 15th cycle, it kept 61% of the laccase activity. Furthermore, HNTs-Fe3O4-CTs-S-S-Laccase was applied for redox-mediated removal of textile dye DR80 and pharmaceutical compound ampicillin. The obtained result marked the potential of the HNTs-Fe3O4-CTs-S-S-Laccase for the removal of hazardous pollutants. This nanosupport is based on clay mineral HNTs, made from low-cost biopolymer CTs, super-magnetic in nature, and can be applied in laccase-based decontamination of environmental pollutants. This study also gave excellent material HNTs-Fe3O4-CTs-SH for other enzyme immobilization processes.

Green-Synthesis of Anisotropic Peptone-Silver Nanoparticles and Its Potential Application as Anti-Bacterial Agent.

This study demonstrates a green-route-based synthesis of high-concentration suspensions of anisotropic silver nanoparticles (AgNPs) by peptone (Pep), a soluble protein hydrolysate and an abundantly used nutrient source in microbial-media. The transformation of Ag ions from solution into a high-concentration suspension of anisotropic Pep-AgNPs, at an extremely low concentration of peptone (0.02%), indicates that the present green-route synthesis method follows "low volume high concentration nano-synthesis", and, hence, enhances the economic significance of the process. Process optimization with different concentrations of AgNPs (1⁻5 mM), NaOH solution (5⁻40 mM), and peptone (0.004%⁻0.12%) gave the optimized Pep-AgNPs synthesis at 3 mM of AgNO3, 20 mM of NaOH, and 0.02% of the peptone concentrations. The green-route synthesized Pep-AgNPs were structurally characterized by the TEM, XPS, FT-IR, and XRD analyses. The Pep-AgNPs against the clinically relevant bacteria Escherichia coli and Staphylococcus aureus gave significant anti-bacterial properties, with a MIC (minimum inhibitory concentration) of 100 ppm. The colony counting and morphological observation of the bacterial cell under SEM corroborated an anti-bacterial potential of the Pep-AgNPs. Therefore, Pep-AgNPs are green-route synthesized, anisotropic, and have a significant anti-bacterial potential that can be used in many relevant applications.

Surface functionalization of halloysite nanotubes with supermagnetic iron oxide, chitosan and 2-D calcium-phosphate nanoflakes for synergistic osteoconduction enhancement of human adipose tissue-derived mesenchymal stem cells.

Halloysite nanotubes (HNTs) are known to be the highly emerging materials in nano-medicinal applications. However, comprehensive exploitation of HNTs for the regenerative medicinal applications is still necessary to be done. Therefore, towards enhancing the osteogenic potential of human adipose tissue-derived mesenchymal stem cells (hADMSCs), this study synthesized a novel and multifunctional nanoscaffold of chitosan (CTs) functionalized supermagnetic halloysite nanotubes (M-HNTs) decorated with the calcium phosphate 2-D nanoflakes (CaP) (termed as; M-HNTs-CTs-CaP). Stepwise modified nanoscaffolds were characterized by FE-SEM, FE-SEM-EDS, FE-HR-TEM, XPS, FT-IR and VSM analyses. The hADMSCs osteogenic potential was confirmed by calcification (Alizarin Red S staining), phosphate quantification and immunocytochemistry. Nanoscaffolds; CaP, M-HNTs-CaP and M-HNTs-CTs-CaP were significantly enhanced and up-regulated osteogenic potential compared to the HNTs, M-HNTs, M-HNTs-CTs. Among the nanoscaffolds studied, M-HNTs-CTs-CaP exhibited highest osteogenesis, due to the enhanced CaP distribution on M-HNTs-CTs surface, and synergistic osteoconduction contributed from Fe3O4, chitosan and CaP. Moreover, immunocytochemistry analysis and morphologically observation showed well differentiated osteoblast on the M-HNTs-CTs-CaP surface. Therefore, M-HNTs-CTs-CaP found to have a strong osteogenic potential of hADMSCs, and might be serve as highly applicable, next generation nanoscaffold for bone tissue engineering application.

Berberine-piperazine conjugates as potent influenza neuraminidase blocker.

In these studies, we analyzed substituted piperazine based berberine analogs conjugated through a pentyloxy side chain for their in vitro and in silico biological effects. All the final analogs were screened for their in vitro antiviral action against a collection of different influenza virus strains using the CPE assay and SRB assay. Moreover, their cytotoxicity towards non-cancer cell lines was examined employing Madin-Darby canine kidney (MDCK) cell lines. The anti-influenza activities of berberine-piperazine derivatives (BPD) were evaluated in the range from 35.16 µg/mL to 90.25 µg/mL of the IC50s along with cytotoxicity level which was observed in the range 44.8 µg/mL to 3890.6 µg/mL of CC50s towards MDCK cells. In an effort to know the mechanism of action of BPD1-BPD23, results of Neuraminidase inhibition assay and Molecular docking studies carried out against neuraminidase as the target enzyme revealed that titled compounds are potential neuraminidase inhibitors that merge to the active site of neuraminidase, with moderate to high binding energy.

Anti-proliferative applications of laccase immobilized on super-magnetic chitosan-functionalized halloysite nanotubes.

Owing to the ubiquitous availability and simple biocatalysis, the anti-proliferative laccase holds enormous opportunities for anti-cancer applications. However, accessing efficient and specific (super-magnetically targetable) new delivery system for anti-proliferative laccase is vital step towards laccase based anti-cancer approach. Therefore, in this investigation, super-magnetized (Fe3O4) and chitosan (CS) functionalized halloysite nanotubes (HNTs) (termed as Fe3O4-HNTs-CS) was facile synthesized. Further, laccase from Trametes versicolor was immobilized on Fe3O4-HNTs-CS (termed as Fe3O4-HNTs-CS-Lac). Then free laccase and Fe3O4-HNTs-CS-Lac were evaluated for anti-proliferative properties against cancer cell lines of liver (HepG2), lung (H460), cervix (Hela) and stomach (AGS). Laccase and Fe3O4-HNTs-CS-Lac gave significant cytotoxicity against all studied cancer cell lines. Moreover, the apoptosis analysis and FE-SEM morphology observations of cells support the anti-proliferative potential of laccase immobilized on Fe3O4-HNTs-CS. Therefore, investigated Fe3O4-HNTs-CS-Lac is natural and super-magnetic nano-biocatalyst, having the significant anti-proliferative potential and furthermore, Fe3O4-HNTs-CS can be used as efficient and specific delivery system for other anti-cancer enzymes.

Chitosan-functionalized supermagnetic halloysite nanotubes for covalent laccase immobilization.

Halloysite nanotubes (HNTs) were modified with supermagnetic Fe3O4 (M-HNTs) and functionalized with chitosan (CTA) (termed as M-HNTs-CTA). Furthermore, M-HNTs-CTA were cross-linked using glutaraldehyde and applied for covalent laccase immobilization (M-HNTs-CTA-Lac). Facile-synthesized modified HNTs were structurally characterized by scanning electron microscopy, high resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and thermogravimetric analyses. M-HNTs-CTA-Lac exhibited 92.74 mg/g of laccase immobilization capacity and 92% of activity recovery. Biochemical properties of M-HNTs-CTA-Lac exhibited higher pH and temperature stabilities, with exceptional reusability capabilities until the 11th cycle. Moreover, M-HNTs-CTA-Lac exhibited 87% of 2,2'-azinobis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS)-mediated Direct Red 80 (DR80) decolorization. By the 11th cycle, M-HNTs-CTA-Lac exhibited 33% DR80 decolorization. Therefore, M-HNTs-CTA can function as CTA-modified supermagnetic nonreactors for immobilization of biomacromolecules. The investigated M-HNTs-CTA-Lac are thus biocompatible and environment-friendly biocatalysts for degradation of textile waste, such as DR80, and can be rapidly retrieved from aqueous solution by a magnet after decontamination of environmental pollutants.

Paper waste extracted α-cellulose fibers super-magnetized and chitosan-functionalized for covalent laccase immobilization.

Enormous disposal of paper wastes (PW) causing number of environmental problems. PW is efficiently used to extract multifunctional α-cellulose fibers (αCFs). Thus, αCFs extraction from PW, and functionalization with Fe3O4 and chitosan were successfully performed for immobilization of laccase. Therefore, in this investigation, PW extracted αCFs were tuned with supermagnetic Fe3O4 (M) and functionalized with chitosan (CTA) (M-PW-αCF-CTA). Furthermore, M-PW-αCF-CTA was glutaraldehyde cross-linked for covalent laccase immobilization. The synthesized materials were characterized by FT-IR, TGA, FE-SEM, FE-HR-TEM and VSM analyzes. M-PW-αCF-CTA exhibited magnetic saturation value of 14.72 emu/g. Laccase immobilized on M-PW-αCF-CTA (M-PW-αCF-CTA-Lac) gave 92% of activity recovery and loading capacity of 73.30 mg/g. M-PW-αCF-CTA-Lac showed excellent pH, temperature, and storage stabilities with the exceptional reusability potential. Moreover, M-PW-αCF-CTA-Lac was applied for repeated removal of carcinogenic Direct Red 28 (DR28). Therefore, M-PW-αCF-CTA-Lac is green and economical biocatalyst with extraordinary separation potential can be enforced for environmental pollutants reclamation.

Synthesis and Evaluation of Antioxidant and Cytotoxicity of the N-Mannich Base of Berberine Bearing Benzothiazole Moieties.

BACKGROUND: Berberine, a quaternary ammonium salt from the protoberberine group of benzylisoquinoline alkaloids has drawn high attention for its several biological potencies. OBJECTIVE: To furnish new rationalized derivatives based on berberine core which can deliver promising antioxidant and cytotoxic activities. METHOD: The N-Mannich base of an isoquinoline alkaloid, berberine, bearing substituted benzothiazole moieties was obtained. Novel synthesized analogues were in vitro screened for antioxidant efficacy toward 2,2-diphenyl- 1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) free radicals and in vitro cytotoxicity towards cervical cancer cell lines (HeLa and CaSki), an ovarian cancer cell line (SK-OV-3) and human renal cancer cell line (Caki-2). Cytotoxicity of the compounds toward normal cell lines was examined using the Madin-Darby canine kidney (MDCK) non-cancer cell line. RESULTS: Analogues bearing a methoxy functional group (5e), acid functionality (5c), and a cyano group (5m) showed remarkable radical scavenging potential in DPPH and ABTS bioassays. Potent cytotoxicity exhibited by berberine against the HeLa cell line was attributable to the presence of a 2-aminobenzothaizole moiety (5a) and its 6-chloro congener (5g) on the berberine core, and the 6-cyano group (5m) on the benzothiazole ring revealed strong sensitivity for the CaSki cell line, whereas subjected scaffolds demonstrated diminished activity against the SK-OV-3 cell line. In addition, the compound with a 2-aminobenzothaizole moiety (5a), compound with methoxy functional group (5e) and compound with cyano group appeared with the most significant cytotoxicity effect in Caki-2 cell line. Their structures have been elucidated by FT-IR, 1H NMR, 13C NMR, and elemental analyses (CHN) essential research. CONCLUSION: N-Mannich bases of berberine were efficiently generated utilizing pharmacologically diverse substituted 2-aminobenzothiazole entities and final compounds were found remarkably active in antioxidant and cytotoxic assay. Hence, such types of compounds can be further studied or rationalized in future drug discovery studies.

Supermagnetically Tuned Halloysite Nanotubes Functionalized with Aminosilane for Covalent Laccase Immobilization.

Halloysite nanotubes (HNTs) were tuned with supermagnetic Fe3O4 (M-HNTs) and functionalized with γ-aminopropyltriethoxysilane (APTES) (A-M-HNTs). Gluteraldehyde (GTA) was linked to A-M-HNTs (A-M-HNTs-GTA) and explored for covalent laccase immobilization. The structural characterization of M-HNTs, A-M-HNTs, and A-M-HNTs-GTA-immobilized laccase (A-M-HNTs-GTA-Lac) was determined by X-ray photoelectron spectroscopy, field-emission high-resolution transmission electron microscopy, a magnetic property measurement system, and thermogavimetric analyses. A-M-HNTs-GTA-Lac gave 90.20% activity recovery and a loading capability of 84.26 mg/g, with highly improved temperature and storage stabilities. Repeated usage of A-M-HNTs-GTA-Lac revealed a remarkably consistent relative activity of 80.49% until the ninth cycle. The A-M-HNTs-GTA-Lac gave consistent redox-mediated sulfamethoxazole (SMX) degradation up to the eighth cycle. In the presence of guaiacol, A-M-HNTs-GTA-Lac gave elevated SMX degradation compared with 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) and syrinialdehyde. Therefore, the A-M-HNTs can serve as supermagnetic amino-functionalized nanoreactors for biomacromolecule immobilization. The obtained A-M-HNTs-GTA-Lac is an environmentally friendly biocatalyst for effective degradation of micropollutants, such as SMX, and can be easily retrieved from an aqueous solution by a magnet after decontamination of pollutants in water and wastewater.

Facile synthesis of pectin-stabilized magnetic graphene oxide Prussian blue nanocomposites for selective cesium removal from aqueous solution.

This work focused on the development of pectin-stabilized magnetic graphene oxide Prussian blue (PSMGPB) nanocomposites for removal of cesium from wastewater. The PSMGPB nanocomposite showed an improved adsorption capacity of 1.609mmol/g for cesium, compared with magnetic graphene oxide Prussian blue, magnetic pectin Prussian blue, and magnetic Prussian blue nanocomposites, which exhibited adsorption capacities of 1.230, 0.901, and 0.330mmol/g, respectively. Increased adsorption capacity of PSMGPB nanocomposites was attributed to the pectin-stabilized separation of graphene oxide sheets and enhanced distribution of magnetites on the graphene oxide surface. Scanning electron microscopy images showed the effective separation of graphene oxide sheets due to the incorporation of pectin. The optimum temperature and pH for adsorption were 30°C and 7.0, respectively. A thermodynamic study indicated the spontaneous and the exothermic nature of cesium adsorption. Based on non-linear regression, the Langmuir isotherm fitted the experimental data better than the Freundlich and Tempkin models.

Glutaraldehyde cross-linked magnetic chitosan nanocomposites: Reduction precipitation synthesis, characterization, and application for removal of hazardous textile dyes.

Magnetic chitosan nanocomposites (MCNCs) were synthesized by an inexpensive reduction precipitation technique using a glutaraldehyde cross-linking agent at room temperature. Successful chitosan coating of iron oxide nanoparticles was confirmed by X-ray photoemission spectroscopy. X-ray diffraction data revealed crystalline particle sizes for the iron oxide and MCNCs to be around 6-7 and 8-9 nm, respectively. In addition, the MCNCs exhibited supermagnetic properties having magnetic saturation of 17.5 emu/g. The synthesized MCNCs showed 91.60% absorption of Acid Red 2, while iron oxide 16.40% absorption; enhanced performance in MCNCs was resulted from presence of free amino and hydroxyl groups. Furthermore, the optimum pH and adsorbent concentration were 3 and 1.0 g/L, respectively. The Redlich-Peterson isotherm fit experimental data better than Langmuir and Freundlich models, based on non-linear regression. Finally, MCNCs showed 96% American Dye Manufacturing Institute (ADMI) value removal and gave recovery efficiency of 100%, making them attractive for further practical applications.

Application of novel consortium TSR for treatment of industrial dye manufacturing effluent with concurrent removal of ADMI, COD, heavy metals and toxicity.

The present study was aimed towards the effective bio-treatment of actual industrial effluent containing as high as 42,000 mg/L COD (chemical oxygen demand), >28,000 ADMI (American Dye Manufacturers Institute) color value and four heavy metals using indigenous developed bacterial consortium TSR. Mineral salt medium supplemented with as low as 0.02% (w/v) yeast extract and glucose was found to remove 70% ADMI, 69% COD and >99% sorption of heavy metals in 24 h from the effluent by consortium TSR. The biodegradation of effluent was monitored by UV-vis light, HPLC (high performance liquid chromatography), HPTLC (high performance thin layer chromotography) and FTIR (Fourier transform infrared spectroscopy) and showed significant differences in spectra of untreated and treated effluent, confirming degradation of the effluent. Induction of intracellular azoreductase (107%) and NADH-DCIP reductase (128%) in addition to extracellular laccase (489%) indicates the vital role of the consortium TSR in the degradation process. Toxicity study of the effluent using Allium cepa by single cell gel electrophoresis showed detoxification of the effluent. Ninety per cent germination of plant seeds, Triticum aestivum and Phaseolus mungo, was achieved after treatment by consortium TSR in contrast to only 20% and 30% germination of the respective plants in case of untreated effluent.

Zinc chloride as a coagulant for textile dyes and treatment of generated dye sludge under the solid state fermentation: hybrid treatment strategy.

Dye sludge generation is major drawback of coagulation process. Efficient hybrid technology by combining coagulation and solid state fermentation (SSF) has capacity to solve generated dye sludge problem. Coagulation of 100mg/L Reactive Red 120 (RR120) using ZnCl2 showed 99% color removal. Mixture of textile dyes (MTD) and textile wastewater (TW) showed 96% and 98% ADMI (American Dye Manufacturing Institute) removal after coagulation by ZnCl2. 92% and 94% ADMI removal from MTD and TW dye sludge and 96% decolorization of RR120 sludge was observed respectively by developed microbial consortium (DCM) in 72h under SSF. Scale up of coagulation process by coagulation reactor (CR) having 50L capacity operated for 30min/cycle. CR showed average 94% ADMI removal from TW in 10 successive cycles. Scale up of SSF composting bioreactor (CB) showed complete dye removal from dye sludge obtained from CR (500L of TW) in 30days.

Lichen Permelia perlata: a novel system for biodegradation and detoxification of disperse dye Solvent Red 24.

Lichen is a self-supporting symbiotic association of fungi and algae which was not yet explored for its bioremediation potential. Lichen Permelia perlata showed potential of decolorization and biodegradation of Solvent Red 24 (SR24). Optimum pH and temperature for decolorization was found to be 8 and 50°C, respectively. Induction in the activity of laccase in P. perlata during biodegradation of SR24 showed their involvement. HPTLC, FTIR and GC-HRMS analysis confirmed biodegradation of SR24 in to metabolites such as naphthalen-1-yldiazene, naphthalene, 1-(2-methylphenyl)-2-phenyldiazene and diphenyldiazene. Phytotoxicity and genotoxicity analysis revealed the reduction in toxicity of SR24 after its biodegradation.