ABSTRACT
The study was aimed to determine the concentrations of organochlorine pesticides (OCPs) in bovine milk (both branded and unbranded) collected from in and around Tiruchirappalli city, Southern India. The results of the present investigation indicated that these milk specimens were found to be contaminated with 7 different pesticides. Mirex (higher incidence), Heptachlor, o,p’-DDD, o,p’- DDE, Aldrin, cis and trans-chlordane were detected in the milk samples. The residues were quantitatively determined using Gas Chromatograph-Mass Spectrometer-Quadrupole on electron ionization (EI) mode. The study showed that unbranded milk samples contained higher concentrations of residues than branded. The derived average daily intake of aldrin and DDT has exceeded WHO’s Acceptable Daily Intake.
ABSTRACT
Metals are an inherent component of the environment that pose a potential hazard to human beings and animals. The consumption of fish from the polluted site may result in bioaccumulation of persistent pollutants in ultimate recipient of the food web. In the present investigation muscle tissue, gill and liver of six species of fish collected from Anaikarai dam (11°8’N latitude and 79°27’E longitude) of River Kaveri, South India were analyzed to study the metal accumulation in various tissues. The mean concentrations of Co, Cr, Mn and Zn were found to be higher in gills, but Cu, Ni and Fe were more in liver of all fishes. The mean concentrations of Cr (11.8 μg g-1), Mn (4.4 μg g-1) and Fe (139 μg g-1) in the muscle were exceeding the permissible limit of FAO and WHO which is 1, 0.5 – 1.2 and 1.0 – 4.5 μg g-1 for Cr, Mn and Fe respectively. The fish Parastromateus niger has shown higher concentration of zinc in all the tissues and thus it can be used as a bioindicator species for zinc pollution in aquatic environment.
ABSTRACT
Removal of heavy metal chromium was carried out using the fungus Fusarium oxysporum NCBT-156 strain isolated from soil of leather tanning effluent in in situ condition using potassium dichromate solution with 10 per cent Czapek-dox liquid medium. Biosorbent matrix was developed using Carica papaya plant dry stem to colonize the fungal strain to facilitate bioabsorption process. Bioabsorption of chromium was by metabolically mediated intracellular accumulation process. Maximum efficiency of chromium removal by biosorption upto 90 per cent was achieved at the end of 5th day of incubation (120 h of contact time) for 100 and 200 ppm concentration, upto 80 per cent for 300 and 400 ppm, and upto 65 per cent for 500 ppm to 1000 ppm concentrations with pH ranging from 5.8, 5.6, 5.5, 5.4 and 5.2, respectively for 100, 200, 300, 400, 500-1000 ppm concentration. SDS-PAGE protein profile showed significant difference in 34 kDa protein band after chromium absorption by the fungus. ftir spectroscopic analysis revealed that the main functional groups involved in the uptake of chromium by F. oxysporium strain were carbonyl, carboxyl, amino and hydroxyl groups.
ABSTRACT
Biosynthesis of gold nanoparticles by Streptomycetes from Himalayan Mountain was undertaken for the first time. Out of 10 actinomycete strains tested, four strains (D10, HM10, ANS2 and MSU) showed evidence for the intracellular biosynthesis of gold nanoparticles, among which the strain HM10 showed high potency. Presence of spherical and rod shaped gold nanoparticles in mycelium of the strain HM10 was determined by transmission electron microscopy (TEM) and X-ray diffraction analysis. The average particle size ranged from 18-20 nm. UV spectral analysis indicated that the reduction of chloroauric acid (HAuCl4) occurred within 24 h of reaction period. Further, the strain HM10 showed enhanced growth at 1 and 10 mM concentration of HAuCl4. The gold nanoparticles synthesized by the strain HM10 showed good antibacterial activity against S. aureus and E. coli in well-diffusion method. The potential actinomycete HM10 strain was phenotypically characterized and identified as Streptomyces viridogens (HM10). Thus, actinomycete strain HM10 reported in this study is a newly added source for the biosynthesis of gold nanoparticles.