A response surface model to examine the reactive red 239 sorption behaviors on Rhizoclonium hieroglyphicum: isotherms, kinetics, thermodynamics and toxicity analyses.

The present study is an attempt to investigate the potentiality of Rhizoclonium hieroglyphicum in the removal of reactive red 239 (RR239) from aqueous solution and to assess the toxicity of the treated dye solution. Optimisation of the process variables namely dye and biosorbent concentrations, pH, temperature and incubation time for RR239 removal was performed using Response Surface Methodology (RSM) assisted Box Behnken Design (BBD) model. The recycling and regeneration efficiency of the dye adsorbed alga was evaluated using different eluents under optimized conditions. Further to understand the adsorption mechanism, isotherms, kinetics and thermodynamic studies were performed. UV-vis and FT-IR spectroscopy was employed to confirm the interaction between the adsorbate and biosorbent. The nature of the treated dye solution was assessed using phyto, microbial and brine shrimp toxicity studies. On the basis of quadratic polynomial equation and response surfaces given by RSM, 90% decolorization of RR239 was recorded at room temperature under specified optimal conditions (300 mg/L of dye, 500 mg/L of biosorbent, pH 8 and 72 h of contact time). Desorption experiments demonstrated 88% of RR239 recovery using 0.1 N acetic acid as an eluent and 81% of dye removal in regeneration studies. The data closely aligned with Freundlich isotherm (R2 - 0.98) and pseudo-second-order kinetic model (R2 - 0.9671). Thermodynamic analysis revealed that the process of adsorption was endothermic, spontaneous, and favorable. UV-Vis and FT-IR analyses provided evidence for adsorbate-biosorbent interaction, substantiating the process of decolorization. In addition, the results of phyto, microbial and brine shrimp toxicity assays consistently confirmed the non-toxic nature of the treated dye. Thus, the study demonstrated that R. hieroglyphicum can act as a potent bioremediation agent in alleviating the environmental repercussions of textile dyeing processes.

Ecofriendly Approach on the Removal of Reactive Orange 107 from Aqueous Solutions Using Cladophora Species as a Novel Biosorbent.

The efficiency of Cladophora species for the removal of Reactive Orange 107 (RO107) from the aqueous solution was evaluated through batch adsorption studies by optimising various process parameters such as pH (3-8), dye concentration (100-500 mg/l), biosorbent concentration (100-500 mg/l), temperature (25-45 °C) and contact time (12-108 h). The results revealed that the optimum conditions for RO107 decolourisation (87%) was found on 72 h of incubation with 100 mg/l dye concentration amended with 200 mg/l biosorbent at pH 6 at 25 °C. The mechanism of dye adsorption was evaluated using isotherms, kinetics and thermodynamic models. The experimental data fitted well with Langmuir isotherm and pseudo-second-order kinetic models. Thermodynamic studies revealed that the adsorption process was endothermic, spontaneous and feasible in nature. Recovery of RO107 from the Cladophora sp. was maximum when 0.1 M HNO3 was used as an eluent. UV-Visible, FT-IR and SEM analyses reveal the interaction between the biosorbent-adsorbate and confirm the process of decolourisation by Cladophora sp. In order to evaluate the nature of the untreated and treated dye solutions, toxicological studies were conducted and the results revealed that the treated dye solution was non- toxic as compared with untreated dye solution. The results of the docking study proved that there was a substantial binding energy between RO107 and the protein (Cytochrome C6) of Cladophora sp. Hence, Cladophora sp. proves to be a promising biosorbent to decolourise RO107 and its potential can be explored in the textile sectors.

Exploring the Potential of Nickel Oxide Nanoparticles Synthesized from Dictyota bartayresiana and its Biological Applications.

The present study validates the impact of nickel oxide nanoparticles (NiONPs) biosynthesized from the brown seaweed Dictyota bartayresiana (DB) and its biological applications. The phytochemicals analyzed in the seaweed extract served as a reducing, capping or stabilizing agent in the formation of nanoparticles. UV visible spectrum of nickel oxide nanoparticles synthesized from DB (DB-NiONPs) represented a prominent peak at 392 nm which validates its formation. Fourier Transmission Infrared Spectroscopy (FT-IR) showcased the presence of functional groups in the biomolecules which aids in the stabilization of DB-NiONPs. The X-ray diffractometry (XRD) revealed the crystalline nature of DB-NiONPs and the particle size was calculated as 18.26 nm. The Scanning electron microscope (SEM) illustrates the irregularly shaped DB-NiONPs and the desired elements were depicted in energy dispersive X-ray (EDX) spectrum which confirms the purity of DB-NiONPs. The DB-NiONPs efficiently decolorised the Black B133 (BB133) dye to 86% in 25 min. The data of adsorption studies well fitted into Langmuir isotherm and pseudo-second order kinetic model. The thermodynamic study substantiated the spontaneous, feasible and endothermic process of adsorption. DB-NiONPs revealed enhanced antimicrobial, larvicidal and nematicidal activities against the selected microbes, larva of Culex pipens and juveniles of Meloidogyne incognita respectively. The phytotoxicity studies revealed the DB-NiONPs had a positive impact on the germination and growth of green gram seedlings.

Unraveling the Interaction Mechanism of the Compounds From Cladophora sp to Recognize Prospective Larvicidal and Bactericidal Activities: In vitro and In Silico Approaches.

The present investigation aims to validate the larvicidal and antibacterial potential of Cladophora sp through in vitro and in silico approaches. The presence of phytoconstituents, functional groups and the compounds responsible for antibacterial and larvicidal activity were assessed through FT-IR and GC-MS analyses which unveiled the existence of active secondary metabolites, hydroxyl, alkane and carbonyl groups. The larvicidal and antibacterial activity of algal extract were examined and revealed complete mortality and substantial zone of inhibition was observed against Culex quinquefasciatus and E. coli. To support the in vitro investigation in silico studies were performed. Molecular docking investigations of the selected compounds from GC-MS which exhibited favorable agreement with drug likeness and ADMET properties indicated robust interactions with the larvicidal and bacterial proteins showcasing considerable binding affinities. Notably, 1,2,4-Oxadiazole, 3-(1,3-benzodioxol-5-yl)-5-[(4-iodo-1H-pyrazol-1-yl) methyl]- exhibited strong interactions with the target proteins. Density Functional Theory revealed that the energy gap of the lead compound was reduced and substantiates the occurrence of intermolecular charge transfer. Molecular Dynamic simulations confirms the stability and flexibility of the lead compound. Hence, this investigation offers computational perspectives on the molecular interactions of Cladophora sp, suggesting its suitability as a promising biocontrol agent.

Sodium hydroxide pre-treated Aspergillus flavus biomass for the removal of reactive black 5 and its toxicity evaluation.

The present study was focused on the removal of Reactive Black 5 (RB5) from aqueous solution using pre treated Aspergillus flavus as a biosorbent. Pre-treatment of fungal biomass with 0.1 M sodium hydroxide facilitated the removal of dye effectively when compared to untreated fungal biomass. Optimum biosorption conditions for RB5 removal was determined as a function of dye concentration (50-400 mg/L), biosorbent concentration (100-500 mg/L), incubation time (1-7hrs), pH (3-8) and temperature (20-50 °C). At the optimum conditions, the maximum removal efficiency of RB5 achieved by NaOH pretreated A. flavus was 91%. The dye removal was studied kinetically and it obeys the pseudo-second order model and the experimental equilibrium data well fitted the Langmuir isotherm indicating monolayer adsorption of dye molecules on the biosorbent. The thermodynamic parameters such as a change in free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) were calculated and negative values of ΔG suggested that the dye removal process was spontaneous at all temperatures. Furthermore, the values of ΔH revealed that the adsorption process was endothermic. Recovery of RB5 from the fungal biomass was effective using 0.1 M Na2CO3 as an eluent. The interaction of adsorbate with biosorbent was analyzed using UV-Vis and FT-IR spectroscopy, SEM and XRD analyses. Phytotoxicity and microbial toxicity studies revealed the non-toxic nature of the treated dye solution. Hence, the fungal biomass pretreated with NaOH was efficient in decolorizing RB5 as well as composite raw industrial effluent generated from dyeing industries.

Cytogenotoxicity assessment in Allium cepa roots exposed to methyl orange treated with Oedogonium subplagiostomum AP1.

The present study is an attempt to assess the cytogenotoxic effect of untreated and methyl orange treated with Oedogonium subplagiostomum AP1 on Allium cepa roots. On the fifth day, root growth, root length, mitotic index, mitotic inhibition/depression, and chromosomal abnormalities were measured in root cells of Allium cepa subjected to untreated and treated methyl orange dye solutions. Roots exposed to treated dye solution exhibited maximum root growth, root length and mitotic index, whereas roots exposed to untreated dye solution had the most mitotic inhibition and chromosomal abnormalities. Allium cepa exposed to untreated dye solution revealed chromosomal aberrations such as disoriented and abnormal chromosome grouping, vagrant and laggard chromosomes, chromosomal loss, sticky chain and disturbed metaphase, pulverised and disturbed anaphase, chromosomal displacement in anaphase, abnormal telophase, and chromosomal bridge at telophase, spindle disturbances and binucleate cells. The comet test was used to quantify DNA damage in the root cells of A. cepa subjected to untreated and treated methyl orange solutions in terms of tail DNA (percent) and tail length. The results concluded that A. cepa exposed to methyl orange induced DNA damage whereas meager damage was noted in the treated dye solution. As a result, the research can be used as a biomarker to detect the genotoxic effects of textile dyes on biota.

Decolorization of safranin using Fissidens species and its ecotoxicological assessments: An in vitro and in silico approach.

Decolorization of safranin was investigated using Fissidens species in a batch system under optimized conditions. The decolorization efficiency was improved by optimizing the conditions such as initial pH (3-9), temperature (25-45 °C), initial dye concentration (10-50 mg/L), biosorbent dosage (100-500 mg/L) and contact time (1-6 days). Maximum decolorization (95%) was recorded at initial pH of 6 with dye concentration of 20 mg/L, biosorbent dosage of 200 mg/L at 30 °C and contact time of 2 days. Desorption studies revealed 0.1 N NaOH as the best desorbing agent with 92% recovery on third day. Experimental data well fitted to Langmuir isotherm and Pseudo-second order kinetic model. The negative values of ΔGo and positive value of ΔSo and ΔHo indicates that the reaction is spontaneous, favorable and endothermic. The biosorbent - dye interactions were confirmed using UV-Vis, FT-IR, XRD and FE-SEM with EDX studies. The detoxified nature of the dye degraded metabolites was confirmed by the significant growth of green gram. The color fastness and color strength of the fabrics dyed using Fissidens species treated dye solution were compared with the tap water dyed fabrics which indicated the reuse potential of treated water in textile sector. The decolorization efficiency was further confirmed through in silico approach, where safranin well docked with the active sites of Photosystem II protein D1 of the Fissidens species. Thus, the present study proves that Fissidens species is a promising biosorbent for safranin decolorization and will lay a platform for the control and management of environmental pollution.

Antibacterial activity of Aegle marmelos against leaf, bark and fruit extracts.

The antibacterial activity of the methanol, chloroform and aqueous extracts from the leaves, bark and fruit of A. marmelos was studied using disc diffusion method against Bacillus subtilis, Staphylococcus aureus (Gram Positive), Klebsiella pneumoniae, Proteus mirabilis, Escherichia coli, Salmonella paratyphi A and Salmonella paratyphi B (Gram Negative). Results suggest that the methanolic extract has significant antibacterial activity against tested bacteria. The present study justifies the claimed uses of A. marmelos in the traditional system of medicine to treat various infectious diseases.

ANTIBACTERIAL ACTIVITY OF LEAF EXTRACT OF Abutilon indicum.

Chloroform, ethanol and aqueous extracts of the leaves of Abutilon indicum were investigated for antibacterial activity against Bacillus subtilis, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli and Salmonella typhi. Among the various extracts, maximum antibacterial activity was exhibited by ethanol extract (14, 25, 14, 25, 17, 18 mm) followed by chloroform extract (13, 17, 8, 15, 15, 20 mm) while aqueous extract, showed no activity.