Jasmine R

Heavy metal toxicity can result in damaged or reduced mental and central nervous function, lower energy levels and damage to several internal organs. Several bacteria have naturally developed tolerance to a wide range of toxic heavy metals. Some bacteria have also evolved mechanisms to detoxify heavy metals. Among several metals, silver has been reported to possess medicinal property and hence used as an antibacterial agent. Inspite of this few silver resistant bacteria have been reported in clinical and environmental samples. Prevalence of silver resistance among several isolated strains provided the basis of the current investigation to determine the prevalence of silver resistance in clinical isolates. The goals of this study were 1) to isolate the uropathogens 2) to investigate the presence and prevalence of silver resistance of urine isolates taken from urinary tract infected patients and 3) to obtain the antibiogram pattern and 4) to determine the maximum tolerance range of silver by the isolated uropathogens, thereby standardize the concentration of silver as antibacterial agent.

Effluent discharge from textile and dyestuff industries to neighbouring water bodies and wastewater treatment systems is currently causing significant health concerns to environmental regulatory agencies. Color removal, in particular, has recently become of major scientific interest, as indicated by the multitude of related research reports. Microbial decolorization and degradation of dyes is seen as a cost-effective method for removing these pollutants from the environment. In this review we have examined biological decolorization of dyes used in textile industries. A simple spectrophotometric assay method was adapted to screen for the ability of Pseudomonas aeruginosa isolates from dye industry effluent to degrade the chosen dyes. They were checked for the extent of dye decolorization [Methyl Red, Methyl Blue & Malachite green] at three different concentrations as 40, 60 & 80ppm. Visual and spec decolonization indicated that decolorization was higher in 60ppm concentration of all three dyes, indicating that to be the optimum concentration for degradation by Pseudomonas aeruginosa isolates. We suggest that the addition of bacterium to the microbial mixture indicated that decolorization was higher in case of dyes in 60 ppm concentration. It can also reduce the bulking problems of the effluent by preventing the load of the organic matter from becoming too high.

  The present study deals with isolation, identification and characterization of heavy metal resistant bacteria isolated from sewage water collected in and around Trichy district, South India. Initially, among 26 of the total isolates screened from sewage water, one isolate was selected for study based on high level of heavy metal resistances. On the basis of morphological, biochemical, 16S rDNA gene sequencing and phylogeny analysis revealed that, the isolate was authentically identified as Pseudomonas aeruginosa. The sewage isolate exhibited resistance to Silver (Ag), Copper (Cu) and Zinc (Zn). The maximum tolerance concentration (MTC) of the isolate against Ag, Cu and Zn was determined in solid media. The uptake of heavy metals, present in sewage and detoxification of metal ions by bacteria provide an additional mechanism of environmental bioremediation. The identified heavy metal resistant bacteria could be useful for the bioremediation of heavy metal contaminated sewage and waste water. Key words: Heavy metals; copper; silver; zinc; metal tolerance

  With an intention to screen for bacterial isolates from wound infection exhibiting resistance to antibiotics, we also checked for the resistance to heavy metals, since both may be plasmid borne. Several bacteria have naturally developed tolerance to a wide range of antibiotics and toxic heavy metals. Some bacteria have also evolved mechanisms to detoxify heavy metals. Tolerance of zinc and copper by these bacteria were studied and it was found that gram positive bacteria were more resistant than gram negative bacteria. We could determine the common pattern of resistance of the isolates to both antibiotics and metals. Key words: antibiotics; heavy metals; copper; zinc; metal tolerance