Showing papers by "Ashoke Ranjan Thakur published in 2007"

Studies on Metal Microbe Interaction of Three Bacterial Isolates From East Calcutta Wetland

Abstract: The present paper put forth the isolation and complete characterization of three bacterial isolates from different sites of East Calcutta Wetland (ECW). These isolates show tolerance to heavy metals like Ag, Al, Cu, Cr, Co, Ni, Pb and were found to be efficient metal accumulators as evident from Energy Dispersive X Ray Fluorescence (EDXRF) analysis and Transmission Electron Microscopy (TEM). Beyond intracellular accumulation, these isolates also show metal deposition in form of particles inside the cells which can further open up the area of microbe fabricated nanoparticle generation. The heavy metal accumulation in the cell can trigger different response mechanism such as change in cell morphology which was observed by scanning electron microscopy (SEM). The metal uptake property of these isolates can be applied for the heavy metal removal and recovery from industrial effluents.

Integrated Resource Recovery at East Calcutta Wetland: How Safe is These?

Abstract: East Calcutta Wetland (ECW) is an example of wise use of cities solid and liquid waste through integrated resource recovery, mainly for pisciculture, vegetable as well as paddy cultivation and manure production. Amaranthus caudatus, Amaranthus blithum and Spinacia oleracea grown at ECW were analyzed for their accumulation of elements using Energy Dispersive X Ray Fluorescence (EDXRF) and compared to those grown in south eastern parts of West Bengal (Midnapur). The objective was to analyze the health hazard, if any, underlying the use of wastewater and solid waste for cultivation of green leafy vegetables at ECW. The following results were obtained upon comparing the data collected from the two different sites: (a) higher accumulation in ECW grown plants of elements like Ca, Cu and Pb in Amaranthus caudatus; of Ca in Amaranthus blithum; of Cl and Cu in Spinacia oleracea, (b) for the same species grown in non-ECW site, higher concentration of elements like Mn and Fe in Amaranthus caudatus; of Cl, Mn and Br in Amaranthus blithum; of Ca, Mn, Fe and Br in Spinacia oleracea. The net consumption of the aforementioned elements per person per day was calculated and found to be much below the Recommended Dietary Allowance (RDA) levels in all cases. Thus the vegetables grown out of integrated resource recovery mechanism at East Calcutta Wetland appear to be safe for human consumption. This further corroborated by the healthy appearance of these vegetables. This result has profound implications of far reaching significance for environmental management and health economics.

Characterization of Bacterial Strains Isolated Through Microbial Profiling of Urine Samples

Abstract: The present study was conducted to determine the microbial profile in urine samples. Differential and selective chromogenic culture media were used for the rapid detection, identification and enumeration of urinary tract pathogens namely, E. coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, Enterococcus faecalis, Proteus mirabilis. Urine samples of normal healthy individuals as well as patients with Urinary Tract Infection (UTI) were screened on hicrome agar plates. The cultivable bacteria present in urine were isolated based on chromogenic detection. Antibiotic sensitivity assay, morphological characterization and biochemical tests, namely protease, oxidase, catalase, lipase, DNase and lecithinase assay were performed with the 15 isolates obtained from urine samples. The molecular analyses of the isolates were done through partial sequencing of the 16SrDNA gene; six of them were found to be novel and submitted in GenBank under the accession numbers EF644491-96. Phylogenetic tree of the isolates were constructed by neighbour joining method.

Current Status and Future Trends of Nanoscale Technology and Its Impact on Modern Computing, Biology, Medicine and Agricultural Biotechnology

Abstract: Nanoscale technologies have gone from being just an ambitious concept to being a rapidly advancing area of interdisciplinary science with immense practical importance. Feynman's vision on nanoscience provided great impetus to the development of nanophysics, nanochemistry, nanoelectronics and nanotechnology in general. High resolution microscopic devices such as scanning tunneling microscope, transmission electron microscope and atomic force microscope etc. in mid 1980s allowed researchers to see individual atoms on surfaces and arrange them. The authors (nanobiologists, computer scientists, biotechnologists and material scientists) attempt to provide a review of the state of the art in the field of nanoscale technologies and its impact on various fields of research like computation, basic biology, medicine and agricultural biotechnology. Imprints of memory mechanisms in living systems operating at different levels (e.g. biochemical, immunological and neuronal) have provided inputs to design and fabricate 'bio-inspired' nanoelectronic devices suitable for various applications. Several examples of such nanoscale technology based frameworks and devices are presented in the scenario of their potential role in the development of future nanoscale technologies. Nanoscale technologies might finally revolutionize computational intelligence and thinking. The power and limits of computing processes govern the intelligence, knowledge acquisition and thinking process of human and machine. Present computational methods and models provide us courage to study the problem, but these tools are not yet sufficient to answer the following riddles of machine intelligence - what can computers do better than humans? What can humans do better than computers? And the most important one - what is computable? The authors try to present evidences that show bio-inspired nanoscale technologies might gain the power in helping us to go deeper into these challenges of research in future