Lalit Varshney

An insight into the influence of low dose irradiation pretreatment on the microbial decolouration and degradation of Reactive Red-120 dye.

The influence of low dose irradiation pretreatment on the microbial decolouration and degradation of Reactive Red-120 (RR-120) dye was investigated in detail by using Pseudomonas sp. SUK1. About 27%, 56% and 66% decolouration of 150 ppm RR-120 dye solution was observed by applying 0, 0.5 and 1 kGy doses, respectively, in the first step followed by microbial treatment for 24 h under static condition. Similarly, about 70%, 88% and 90% TOC removal was observed by applying 0, 0.5 and 1 kGy doses, respectively, in the first step followed by the microbial treatment for 96 h under static condition. The radiation induced fragmented products of RR-120 at doses of 0.5 and 1 kGy were investigated by FTIR and electrospray ionization-MS analysis. The induction of the enzymes viz. laccase, tyrosinase, azoreductase and NADH-2,6-dichlorophenol indophenol reductase was studied in the decolourised solution obtained after irradiating 150 ppm RR-120 dye solution with 0 and 1 kGy doses followed by the microbial treatment for 96 h under static condition. The enzymatic degradation products were studied by FTIR, HPLC and GC-MS. The toxicity study of the treated dye solution on plants revealed the degradation of RR-120 into non-toxic products by combined radiation-microbial treatment. This study explores a reliable and promising way to use industrially viable dose (≤1 kGy) and microbial strain viz. Pseudomonas sp. SUK1 for permissible safe disposal of dye solutions from textile industries.

Cellulose based cationic adsorbent fabricated via radiation grafting process for treatment of dyes waste water.

A cationized adsorbent was prepared from cellulosic cotton fabric waste via a single step-green-radiation grafting process using gamma radiation source, wherein poly[2-(methacryloyloxy) ethyl]trimethylammonium chloride (PMAETC) was covalently attached to cotton cellulose substrate. Radiation grafted (PMAETC-g-cellulose) adsorbent was investigated for removal of acid dyes from aqueous solutions using two model dyes: Acid Blue 25 (AB25) and Acid Blue 74 (AB74). The equilibrium adsorption data was analyzed by Langmuir and Freundlich isotherms, whereas kinetic data was analyzed by pseudo first order, pseudo second order, intra particle diffusion and Boyds models. The PMAETC-g-cellulose adsorbent with 25% grafting yield exhibited equilibrium adsorption capacities of ∼ 540.0mg/g and ∼ 340.0mg/g for AB25 and AB74, respectively. Linear and nonlinear fitting of adsorption data suggested that the equilibrium adsorption process followed Langmuir adsorption isotherm model, whereas, the kinetic adsorption process followed pseudo-second order model. The multi-linearities observed in the intra-particle kinetic plots suggested that the intraparticle diffusion was not the only rate-controlling process in the adsorption of acid dyes on the adsorbent, which was further supported by Boyds model. The adsorbent could be regenerated by eluting the adsorbed dye from the adsorbent and could be repeatedly used.

Utilizing the γ-Irradiated Sodium Alginate as a Plant Growth Promoter for Enhancing the Growth, Physiological Activities, and Alkaloids Production in Catharanthus roseus L.

Abstract Sodium alginate is a polysaccharide that is largely obtained from the brown algae (Sargassum sp.). It has been used as a wonderful growth promoting substance in its depolymerized form for various plants. The aim of this study was to find out the effects of various concentrations of γ-irradiated sodium alginate (ISA), viz., deionized water (control, T0), 20 (T1), 40 (T2), 60 (T3), 80 (T4), and 100 ppm (T5) on the agricultural performance of Catharanthus roseus L. (Rosea) in terms of growth attributes, photosynthesis, physiological activities, and alkaloid production. The present work revealed that ISA applied as leaf-sprays at concentrations from 20 to 100 ppm might improve growth, photosynthesis, physiological activities, and alkaloid production in C. roseus L. significantly. Of the various ISA concentrations, 80 ppm proved to be the best one compared to other concentrations applied.

Depolymerized carrageenan ameliorates growth, physiological attributes, essential oil yield and active constituents of Foeniculum vulgare Mill.

Irradiated carrageenan (IC) elicits an array of plant defense responses and biological activities in plants. An experiment was carried out in the naturally illuminated conditions of net house in order to assess the effects of foliar spray of IC on agricultural performance of fennel (Foeniculum vulgare Mill.), which is a high-value essential oil bearing medicinal crop used in pharmaceutical, food and cosmetic industries. There were applied four IC concentrations (40, 60, 80 and 100 mg L(-1)) as foliar sprays. Application of IC significantly improved the growth attributes, physiological and biochemical parameters, essential oil yield and the contents of main components of essential oil of fennel. IC applied at 80 mg L(-1) enhanced these parameters maximally. Unirradiated carrageenan and deionized water had no effect on the attributes studied. Moreover, GLC analysis revealed a significant increase in the components of essential oil, viz. fenchone (4.48-7.82%) and anethole (78.38-86.08%) compared to the control.

Irradiated sodium alginate improves plant growth, physiological activities and active constituents in Mentha arvensis L.

Sodium alginate, irradiated by Co-60 gamma rays in solid state, elicits plant growth promoting responses in various plants. Irradiated sodium alginate (ISA) was applied as a foliar spray on mint (Mentha arvensis L.) to investigate its effect on plant growth, physiological attributes and herbage yield as well as on content and yield of essential oil and its components (menthol, L-menthone, isomenthone and methyl acetate). A simple pot experiment was conducted applying five concentrations of ISA, viz. 25, 50, 75, 100 and 125 mg L, as foliar sprays. GPC study revealed formation of lower molecular weight oligomer fractions in irradiated samples which could be responsible for plant growth promotion in the present work. Of the five ISA concentrations, 100 mg L proved the best. As compared to the control, the ISA applied at 100 mg L resulted in the highest values of all physiological parameters at 100 and 120 days after planting.

Effect of irradiated sodium alginate and phosphorus on biomass and artemisinin production in Artemisia annua.

It is now being realized that irradiation products of natural bioactive agents can also be beneficially utilized to impart value addition in agriculture by converting these bioactive agents into more useful form. Polysaccharides, such as sodium alginate, have proven to be wonderful growth promoting substances in their depolymerized form for various plants. Artemisinin has been increasingly popular as an effective and safe alternative therapy against malaria; also proved effective against the highly adaptable malaria parasite, which has already become resistant to many other drugs. The drug artemisinin can be extracted from the leafy tissues of Artemisia annua. Therefore, experiments were conducted with an aim to evaluate artemisinin production and overall plant development though depolymerized sodium alginate application and nutrient supply. In the present study, sodium alginate, irradiated by Co-60 gamma rays together with various phosphorus doses, was used to study their effect on growth, physiological and biochemical processes and production of artemisinin in A. annua. Among various applied doses of phosphorus fertilizer, P40 (40 kg Pha(-1)) together with ISA80 (80 mg L(-1)) significantly improved all the parameters studied. Increase in plant height as well as weight was noted at this treatment. Dry leaf yield, artemisinin concentration in leaves and artemisinin yield was also significantly enhanced by the treatment.

An insight into the effective advanced oxidation process for treatment of simulated textile dye waste water

The efficiencies of the advanced oxidation processes (AOP) viz. photocatalysis, ozonolysis and gamma radiolysis in the absence and presence of potassium persulfate (K2S2O8) were systematically investigated for the treatment of simulated textile dye waste water (STDWW) containing Reactive Red 120. The oxygen-equivalent chemical-oxidation capacities of photocatalysis, ozonolysis and gamma radiolysis in the absence and presence of K2S2O8 for 16% mineralization of STDWW were calculated as 4.02, 16.19, 0.13, 0.05 kg equiv. O2 m−3, respectively. The gamma radiolysis in the presence of K2S2O8 showed the maximum extent of mineralization among these three AOPs. The pulse radiolysis studies revealed that the favourable reaction of SO4˙− with SDBS (the most robust organic component of STDWW) producing benzyl and hydroxycyclohexadienyl type of radicals caused the enhancement in the extent of mineralization of STDWW during gamma radiolysis in the presence of K2S2O8. The COD of the STDWW was brought down to 1558 ppm from 3128 ppm by gamma radiolysis at 50 kGy dose in the presence of K2S2O8; though that index could not meet the allowed discharge limit (COD ≤ 250 ppm) of industrial effluent in the main water stream. Conversely, on replacing organic acid (CH3COOH) by inorganic acid (H2SO4) in the pH adjustment step, COD of STDWW was brought down to 245 ppm by gamma radiolysis at 60 kGy in the presence of K2S2O8. This paper recommends using H2SO4 in place of CH3COOH in the pH adjustment step followed by the gamma radiolysis of STDWW in the presence of K2S2O8 for an effective effluent treatment.

Designing tragacanth gum based sterile hydrogel by radiation method for use in drug delivery and wound dressing applications

Present article discusses synthesis and characterization of the sterile and pure hydrogel wound dressings which were prepared through radiation method by using polyvinyl alcohol (PVA), tragacanth gum (TG) and sodium alginate (SA). The polymer films were characterized by SEM, Cryo-SEM, FTIR, solid state C(13) NMR and XRD, TGA, and DSC. Some important biological properties such as O2 permeability, water vapor transmission rate, microbial permeability, haemolysis, thrombogenic behavior, antioxidant activity, bio-adhesion and mechanical properties were also studied. The hydrogel film showed thrombogenicity (82.43±1.54%), haemolysis (0.83±0.09%), oxygen permeability (6.433±0.058mg/L) and water vapor permeability (197.39±25.34g/m(2)/day). Hydrogel films were found biocompatible and impermeable to microbes. The release of antibiotic drug moxifloxacin occurred through non-Fickian mechanism and release profile was best fitted in Hixson-Crowell model for drug release. Overall, these results indicate the suitability of these hydrogels in wound dressing applications.

Design of sterile mucoadhesive hydrogels for use in drug delivery: Effect of radiation on network structure

Radiation induced graft copolymerization is pure, sterile and additive free method for the synthesis of hydrogels for biomedical applications. In the present work, attempt has been made to prepare the biocompatible, mucoadhesive hydrogels based on natural polysaccharide sterculia gum and polyvinylpyrrolidone (PVP) for use as drug delivery devices. The effect of gamma radiation on swelling and various network parameters of hydrogels such as the polymer volume fraction in the swollen state (ϕ), molecular weight of the polymer chain between two neighboring cross links (M¯c), crosslink density (ρ), and mesh size (ξ) have been studied. Hydrogels have been characterized with scanning electron micrographs (SEMs), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction study (XRD), thermo gravimetric analysis (TGA) and swelling studies. Swelling and mesh size decreased while gel strength and crosslink density increased with increase in radiation dose. The swelling of hydrogels and release of drug ciprofloxacin from drug loaded hydrogels occurred through non-Fickian diffusion mechanism. These hydrogels have been observed to have non-thrombogenic, haemo-compatible and mucoadhesive nature and could be used as mucoadhesive drug delivery system to deliver drug to gastro intestinal tract (GIT) in controlled manner.

Radiolytically depolymerized sodium alginate improves physiological activities, yield attributes and composition of essential oil of Eucalyptus citriodora Hook

Eucalyptus citriodora Hook. is highly valued for its citronellal-rich essential oil (EO) extracted from its leaves. Hence, escalated EO production of eucalyptus is the need of hour. Marine polysaccharides (sodium alginate) are processed through gamma radiation of particular intensity, to obtain the irradiated sodium alginate (ISA). A pot experiment was conducted to study the effect of foliar application of ISA on growth, biochemical, physiological, EO yield and composition of E. citriodora. The treatments were applied as: foliar spray of deionized water only (control), seed soaked with ISA (90 mg L(-1)) and foliar spray of ISA with 30, 60, 120 and 240 mg L(-1). The treatment 6 (spray of ISA at 120 mg L(-1)) showed the highest value for most of the parameters studied. It also enhanced the EO content (33.3%), EO yield (86.7%), citronellal content (63.4%) and citronellal yield (205.5%) as compared to the control.