Threat to food security under current levels of ground level ozone: A case study for Indian cultivars of rice

A higher ozone concentration in rural agricultural region poses threat to food production in developing countries. The present study was conducted to evaluate the growth, biomass accumulation and allocation pattern, quantitative and qualitative characteristics of grains for two tropical rice cultivars (Oryza sativa L. cv NDR 97 and Saurabh 950) at ambient O₃ concentrations at a rural site in the Indo Gangetic plains of India.Percent inhibition in number of leaves was higher for NDR 97, but in leaf area for Saurabh 950 grown in non filtered chambers (NFCs) compared to filtered chambers (FCs). Higher inhibition in root biomass was recorded in Saurabh 950 and in leaf and standing dead biomass for NDR 97. During vegetative phase, relative growth rate showed more percent inhibition in Saurabh 950, but at reproductive phase in NDR 97. Net assimilation rate showed higher values for Saurabh 950 than NDR 97 in NFCs but percent inhibition in leaf area ratio was higher for former than latter cultivar in NFCs. The ozone resistance was higher in NDR 97 during vegetative phase, but in Saurabh 950 at reproductive phase. Number of grains was higher in NDR 97 than Saurabh 950, but test weight and weight of grains m^?2 showed reverse trends. Concentrations of starch, protein, P, N, Ca, Mg and K decreased, while reducing and total soluble sugar increased in grains of both the cultivars in NFCs compared to FCs. The study concluded that under ambient condition of O₃ exposure, the two cultivars responded differently. Saurabh 950 favoured biomass translocation priority towards ear in reproductive phase and hence showed higher resistivity due to maintenance of higher test weight. NDR 97, however, showed better growth during vegetative period, but could not allocate efficiently to developing ears, hence higher number of unfilled grains in NFCs led lower test weight.     

Enhanced antimicrobial activity of the food-protecting nisin peptide by bioconjugation with silver nanoparticles

Nisin is an antimicrobial peptide widely used in the food industry. The efficacy of nisin has decreased due to the development of resistant bacteria. For instance, bacteria such as Staphylococcus aureus have resistance by digesting nisin using the nisinase enzyme. The efficacy of nisin could be improved using bioconjugation with metal nanoparticles. Here we synthesized silver nanoparticles using the extract of Cymbopogon citratus; then, we bioconjugated those silver nanoparticles with nisin to form a nanosilver bioconjugate. Silver nanoparticles and silver bioconjugate were characterized by UV–Vis spectroscopy, nanoparticle tracking analysis, zeta potential measurement and transmission electron microscopy. In vitro antimicrobial efficacy of both silver nanoparticles and silver bioconjugate was evaluated against selected food spoilage microorganisms such as Listeria monocytogenes, S. aureus, Pseudomonas fluorescens, Aspergillus niger and Fusarium moniliforme. Results show that the antimicrobial potential of nisin increased after bioconjugation with silver nanoparticles. Further, we developed agar film containing nanosilver bioconjugate and also evaluated its antimicrobial activity against selected food spoilage microorganisms. The agar film demonstrated maximum activity against P. fluorescens, of 19 mm, and the minimum against F. moniliforme, of 12 mm. Overall, agar film containing nisin and silver nanoparticles can be used against food spoilage microorganisms.     

Dissipation of sulfamethoxazole and trimethoprim antibiotics from manure-amended soils

In this study, the dissipation of two antibiotics, sulfamethoxazole (SMX) and trimethoprim (TRM), in three soils under both aerobic and anaerobic conditions are evaluated. Under aerobic conditions, SMX dissipated rapidly through biodegradation but TRM was more persistent. Within the first 20 days in biologically active soils, >50% of the SMX was lost from the clay loam and loamy sand soils, and >80% loss was noted in the loam soil. Anaerobic dissipation of both compounds was more rapid than aerobic dissipation. The addition of manure to the soil only slightly increased the initial dissipation rate of the two compounds. Little effect was found on glucose mineralisation in soil following the addition of SMX and TRM, even as mixtures at high concentrations.     

Miscibility Studies of Polysaccharide Xanthan Gum/PVP Blend

Miscibility characteristics of Xanthan gum and Poly (vinyl pyrrolidone) (PVP) in common solvent water were studied by viscometry, ultrasonic velocity and density techniques at 30 and 50 °C. Blend films of Xanthan gum/PVP were prepared by solution casting method and characterized by scanning electron microscopic (SEM) and differential scanning calorimeter (DSC) techniques. Using the viscosity data, interaction parameters of Chee’s (μ) and Sun’s (α) were computed to determine their miscibility. The values obtained revealed that blends were miscible when PVP content is up to 70% in blend at 30 °C. Xanthan gum/poly (vinyl pyrrolidone) blends showed miscibility in all composition at 50 °C. The results were then confirmed by ultrasonic velocity, density, and DSC techniques. Compatibility in the above compositions may be due to the formation of hydrogen bonding between the carbonyl group in PVP and hydroxyl group in Xanthan gum. Further, the results revealed that change in temperature had significant effect on the miscibility of Xanthan gum/Poly (vinyl pyrrolidone) blends.     

浅析海洋环境影响评价中公众参与存在的问题与对策

针对目前海洋环境影响评价中存在的公众参与意识不强,参与程度不够深入,公众意见的分析评价不够客观等问题,本文提出通过建立一个人员相对稳定且比例适宜的"公众参与库",方便工程部门、评价部门和公众之间进行交流沟通;对公众的调查意见采用"量化评价"的方法,消除分析评价中的主观干扰因素,从而客观判别项目的合理性和社会可接受性。     

Bioremediation of pulp and paper mill effluent with Phanerochaete chrysosporium

The present study reports on the treatment of pulp and paper mill effluent by Phanerochaete chlysosporium and the same has been compared at two different pH, 5.5 and 8.5. At both the pH, colour, COD, lignin content and total phenols of the effluent significantly declined after bioremediation. However, greater decolourisation and reduction in COD, lignin content and total phenols were observed at pH 5.5. Such bioremediated effluent of pulp and paper mill could gainfully be utilized for crop irrigation.     

On-line solid-phase extraction and fluorescence detection of selected endocrine disrupting chemicals in water by high-performance liquid chromatography

A high-performance liquid chromatographic method was developed to analyse selected endocrine disrupting chemicals in water by using automated on-line solid-phase extraction with a fluorescence detector. The excitation and emission wavelengths of the fluorescence detector were 230 nm and 290 nm, respectively. The selected endocrine disrupting chemicals include hormone steroids such as estradiol (E2), estriol (E3), ethynylestradiol (EE2), and ethynylestradiol 3-methyl ether (MeEE2) as well as nonylphenols (NP), octylphenols (OP), POE(1-2) nonyl phenol (NPE) and bisphenol A (BP). Three types of on-line cartridges (C18, PLRP-s and PRP-1) were tested to pre-concentrate the endocrine disruptors in deionised water. It was found that the recoveries of these chemicals at 1 microg/L were close to 100% except for 4-octyl phenol and 4-n-nonyl phenol, which had recoveries of about 40% to 80%. The two polymer cartridges (PLRP-s and PRP-1) gave higher recoveries than the C18 cartridges. The addition of methanol at 5% to 10% in water significantly improved the recovery of 4-octyl phenol and 4-n-nonyl phenol. The addition of methanol also led to an improvement in the recovery with C18 cartridges. With the addition of methanol in water samples, these three types of cartridges gave similar recoveries for the chemicals. The detection limits of this method ranged from 20 ng/L to 50 ng/L. A river water sample spiked with these chemicals was analysed using the above method and we found no interference with the peaks of the selected endocrine disrupting chemicals. The recoveries for these chemicals were more than 92% except for 4-NP with a recovery of 61%. This relatively simple method is useful for laboratory studies on the environmental fate of these endocrine disrupting chemicals in water.     

Toxic metals and organochlorine pesticides residue in single herbal drugs used in important ayurvedic formulation – ‘Dashmoola’

Herbal formulations are getting popularity throughout the world and commercialized extensively for various medicinal properties. WHO has emphasized the need for quality assurance of herbal products, including testing of heavy metals and pesticides residues. 'Dashmoola', a popular herbal formulation, with immunomodulator and febrifugal properties, consists of ten single root drugs. In view of WHO guidelines, single herbal drugs used in 'Dashmoola', were collected from different places of India for testing heavy metals and persistent pesticides residue. Although use of roots in 'Dashmoola' is prescribed in original ayurvedic literature but now many pharmacies use stem in place of roots. Therefore, in the present study both roots and stems were selected for estimation of six heavy metals namely arsenic (As), mercury (Hg), lead (Pb), cadmium (Cd), chromium (Cr) and nickel (Ni). Apart from these, the organochlorine pesticides residue viz. different metabolites of DDT, DDE, isomers of HCH and alpha-endosulfan were checked in total 40 samples of single crude drugs. Heavy metals except Hg, were present in most of the samples. In few samples Pb and Cd concentration were beyond the WHO permissible limits. Although alpha-HCH and gamma-HCH were present in almost all the samples, but other pesticides were not detected in these samples. DDT and DDE were found only in two samples.