N. Tejo Prakash

Modulations in antioxidant enzymes in different tissues of marine bivalve Perna viridis during heavy metal exposure.

Lipid peroxidation induced by metals at sub-lethal levels, alter physiological and biochemical characteristics of biological systems. To counter the detrimental effects of the prooxidant activity of metals, a group of antioxidant enzyme systems function in the organisms. The present study was performed to investigate into the lipid peroxidation product formation due to the exposure to effects of the metals namely aluminium, lead and cadmium at sub-lethal concentrations and the biological response through protective antioxidant enzyme activity in the marine mussels,Perna viridis Lin. This organism is a known bioindicator and bioconcentrator of metals in the environment.The results of the present study were: (a) accumulation of lead showed a definite linear increase during the period of exposure whereas aluminium and cadmium showed fluctuations. Mantle and gill tissues showed greater accumulation of metals when compared to digestive gland; (b) lead and aluminium induced lipid peroxidation was greater in tissues than the peroxidation induced by cadmium. Cadmium induced peroxidation was observed only after the day 7 of the exposure; (c) anti-oxidant enzymes activity levels were significantly higher in digestive gland and mantle than gills; (d) mantle was observed to significantly contribute to the organismal response to lipid peroxidation as indicated by high activity levels of anti-oxidant enzymes.

Aerobic microbial manufacture of nanoscale selenium: exploiting nature’s bio-nanomineralization potential

The potential of the environment to yield organisms that can produce functional bionanominerals is demonstrated by selenium-tolerant, aerobic bacteria isolated from a seleniferous rhizosphere soil. An isolate, NS3, was identified as a Bacillus species (EU573774.1) based on morphological and 16S rRNA characterization. This strain reduced Se(IV) under aerobic conditions to produce amorphous α Se(0) nanospheres. A room-temperature washing treatment was then employed to remove the biomass and resulted in the production of clusters of hexagonal Se(0) nano-rods. The Se(0) nanominerals were analyzed using electron microscopy and X-ray diffraction techniques. This Bacillus isolate has the potential to be used both in the neutralizing of toxic Se(IV) anions in the environment and in the environmentally friendly manufacture of nanomaterials.

Bioaccessibility of selenium from Se-rich food grains of the seleniferous region of Punjab, India as analyzed by instrumental neutron activation analysis

In the present study, selenium (Se) bioaccessibility was measured in rice and maize cultivated in seleniferous soil of India using in vitro gastric (GA) digestion and gastro-intestinal (GI) digestion methods. The concentration of bioaccessible Se was determined by instrumental neutron activation analysis (INAA). The total Se was observed to be about 58.0 mg kg−1 and 29.0 mg kg−1 in flours of rice and maize, respectively. Total Se content in maize flour sample after GA and GI digestions were approximately 9.5 mg kg−1 and 15.0 mg kg−1, respectively; and in case of rice samples, the levels were about 32.0 mg kg−1 and 38.0 mg kg−1, respectively. The results indicate that the bioaccessibility of GI digestion (51% in maize and 65% in rice) was higher compared to GA digestion (32% and 52% in maize and rice, respectively). In addition, the bioaccessible levels of Se were significantly more in case of rice compared to maize.

Selenium Mobilization by Pseudomonas aeruginosa (SNT-SG1) Isolated from Seleniferous Soils from India

Selenium (Se) is a metalloid required at trace concentrations for normal metabolic activities of the cell. The bioavailable forms viz., selenate and selenite have been found in localized high concentrations in seleniferous environments. Studies are in progress on bacterial strains that were isolated from one such location in the North-West region of Punjab, India. A facultative anaerobe, identified as Pseudomonas aeruginosa by 16S rRNA gene homology, was isolated from the rhizosphere of crop plants from this region and was examined for selenium mobilization potential in the presence of selenium oxyanions. The isolate was observed to reduce 53 and 21% of sodium selenite and selenate to elemental selenium, respectively, and volatilize 4.7 and 5.1% within 72-hour duration. This is one of the few selenium tolerant aerobic bacteria isolated and reported from tropical seleniferous soils from India, and the first to show volatilization potential. These organisms are being considered for bioaugmenting Se-impacted soils for enhanced Se mobilization and removal.

Imbalance of dietary nutrients and the associated differentially expressed genes and pathways may play important roles in juvenile Kashin-Beck disease.

BACKGROUND Kashin-Beck disease (KBD) is a childhood-onset endemic osteoarthropathy in China. Nutrients including trace elements may play active roles in the development of KBD. OBJECTIVE This study aimed to estimate the nutrient intakes of children in endemic areas and to identify the imbalanced nutrients associated differentially expressed genes in the juvenile patients with KBD. METHODS In this cross-sectional study, a consecutive 3 day 24 h semi-quantitative dietary retrospect questionnaire was conducted to estimate the daily nutrient intakes of children using CDGSS 3.0 software. Gene profile analysis was employed to identify differentially expressed genes in peripheral blood mononuclear cells of children with KBD. GOC, CTD, KEGG, and REACTOME databases were used to establish the relationship between nutrients and nutrients-associated differentially expressed genes and pathways. Statistical analyses were accomplished by SPSS 18.0 software. RESULTS Daily Se intakes without supplementation of children were significantly lower in Se-supplemented (Se + ) KBD areas (29.3 ∼ 29.6 mg/d) and non-endemic area (27.8 ± 7.9 mg/d) compared to non-Se-supplemented (Se-) KBD area (32.9 ± 7.9 mg/d, c2 = 20.24, P < .01). Children in Se+ KBD areas were suffering more serious insufficient intake of multiple nutrients, including vitamins-B2/-C/-E, Ca, Fe, Zn and I. Gene profile analysis combined with bioinformatics technique identified 34 nutrients associated differentially expressed genes and 10 significant pathways which are related to the pathological changes in juvenile KBD. CONCLUSIONS Imbalance of dietary nutrients and nutrients-associated differentially expressed genes and pathways may play important roles in the development of juvenile KBD.

Fuel properties of blend and biodiesel generated from acid oil using whole cell biocatalyst

ABSTRACT Biodiesel was generated through whole cell catalyzed transesterification of acid oil, to the extent of up to 92%. The fuel properties of biodiesel (B100) and its blend (B20) were determined and compared with standard biodiesel as per American Society for Testing and Materials (ASTM) standard (ASTM D6751). B100 and B20 showed good pour point of −26°C and −29°C, respectively, indicating their operation viability in colder environment. Other properties of biodiesel are quite similar to petroleum diesel and ASTM standard. The results of this study reveal the potential use of acid oil as feedstock for generation of fuel grade biodiesel through biocatalyzed transesterification.

Quantification and In Vitro Bioaccessibility of Selenium from Osborne Fractions of Selenium-Rich Cereal Grains

Cereal crops cultivated in the seleniferous belt of Punjab, India, were observed to hyperaccumulate a significantly high concentration of selenium (20–123 µg/g). Selenium concentration (µg/g) in storage proteins of wheat, maize, and rice, namely, albumin (401, 280, and 29, respectively), globulin (264, 192, and 242, respectively), glutelin (563, 359, and 178, respectively), and prolamin (629, 339, and 257, respectively) indicated variable selenium levels, with prolamin contributing significantly higher levels of selenium when compared with other proteins with reference to the total concentration of the protein fraction. The simulated gastric and gastrointestinal digestion studies indicated better accessibility of selenium during intestinal digestion, with variability across proteins and cereal types. The observations provide an insight into the bioavailability of selenium in selenium-rich cereal grains, used in the study, and their potential use as source for selenium supplementation to deficient populati...

Selenium fortification and pro/anti oxidant responses in Allium cepa (onion) cultivated in Se supplemented soils.

Native plantlets of Allium cepa (onion) were cultivated in selenium (Se)-supplemented soils to observe dose- and time-dependent uptake and associated pro/anti-oxidant activity. Allium plantlets were grown in soils supplemented with Se at 2.5, 5.0 and 7.5 mg kg −1 as selenite (Na 2 SeO 3 ) and selenate (Na 2 SeO 4 ) for 40–120 days. The effect of different concentrations of Se oxyanions on the growth and accumulation profile in plants in relation to glutathione peroxidase activity and thiobarbituric acid reactive substances was studied. Total Se concentrations in plantlets were determined by instrumental neutron activation analysis. The accumulation of Se in plant was observed to be dose dependent in the case of selenite, but, no definite correlation between accumulation levels and exposed concentration was observed. The changes in pro/anti-oxidant properties were observed to be dependent on the accumulation of Se in plant.

The Level of Toxic Elements in Edible Crops from Seleniferous Area (Punjab, India)

The primary objective of the present study was to assess the level of selenium and toxic trace elements in wheat, rice, maize, and mustard from seleniferous areas of Punjab, India. The content of selenium (Se) and toxic trace elements, including aluminum (Al), arsenic (As), cadmium (Cd), mercury (Hg), nickel (Ni), lead (Pb), and tin (Sn), in crop samples was assessed using inductively coupled plasma mass-spectrometry after microwave digestion of the samples. The obtained data demonstrate that cultivation of crops on seleniferous soils significantly increased Se level in wheat, mustard, rice, and maize by a factor of more than 590, 111, 85, and 64, respectively. The study also showed that Se exposure affected toxic metal content in crops. In particular, Se-rich wheat was characterized by a significant decrease in Al, As, Ni, Pb, and Sn levels. The level of As, Cd, Ni, Pb, and Sn was significantly decreased in Se-rich rice, whereas As content was increased. In turn, the decrease in Al, As, Cd, Ni, Pb, and Sn levels in Se-rich maize was associated with a significant elevation of Hg content. Finally, Se-rich mustard was characterized by a significant increase in Al, As, and Hg levels, while the content of Ni, Pb, and Sn was significantly lower than the control levels. These findings should be taken into account while developing the nutritional strategies for correction of Se status. At the same time, the exact mechanisms underlying the observed differences are to be estimated.

Biocatalyzed esterification of oleic acid using cell suspension and dried biomass of Aspergillus sp. RBD01

Abstract Esterification is an industrially important reaction in the field of food and fuel industries. In biofuel and allied industries, long-chain alkyl esters are generally produced from different fat rich feedstocks including non-edible oils, acid oils, and tallow, using a variety of catalysts. Amongst these, whole cell systems have prominently been explored in recent past. The present study focused on the use of Aspergillus sp. RBD01 as a whole cell catalyst, in dry and whole cell suspension, to esterify oleic acid with different alcohols as acyl acceptors. Esterification with dried biomass resulted in better conversion of oleic acid to its respective ester as compared to cell suspension. Further, increase in chain length of alcohol resulted in decrease in the yield from ethyl oleate (98% EO) to decyl oleate (77% DO) with alcohols having an even number of carbon atoms giving better yield of esters over alcohols with odd numbers.