Sequestration of cobalt and nickel by biofilm forming bacteria isolated from spent nuclear fuel pool water.

In the current study, six bacterial types, isolated from spent nuclear fuel (SNF) pool facility, were investigated for their ability to sequester heavy metals (cobalt and nickel). Biofilm formation by the six bacterial isolates, viz., Bacillus subtilis, Staphylococcus species, Staphylococcus arlettae, Staphylococcus epidermidis, Staphylococcus auricularis, and Chryseobacterium gleum, were assayed, and they were found to have significant biofilm forming property. Their biofilms were characterised using confocal scanning laser microscopy, and their potential to accumulate Co2+ and Ni2+ from bulk solutions was analysed with respect to time. A comparative assessment of bioaccumulation capacity was done using biofilms, planktonic cells, and live vs dead cells. The strains accumulated Co2+ and Ni2+ in the range of 4 × 10-4 to 1 × 10-5 g/mg of cell biomass. It is interesting to note that dead biomass also showed significant removal of the two metal ions, suggesting an alternative process for metal removal. This study suggests that hostile environments can be a repertoire of putative bacterial species with potential heavy metals and other contaminants remediation properties.

Microbiota of spent nuclear fuel pool water with emphasis on their biofilm forming ability on stainless steel (SS-304L).

Spent nuclear fuel (SNF) pool is an essential unit of a nuclear power plant infrastructure, where radioactive fuel rods are kept for cooling and shielding, before reprocessing. This study explored the presence of bacteria in SNF pool water with emphasis on their capability to form biofilms on pool wall cladding material stainless steel (SS-304L). Bacteria were isolated from SNF pool water and were characterized using 16S rRNA gene sequencing. The six bacterial isolates (Bacillus subtilis, Staphylococcus sps., S. arlettae, S. epidermidis, S. auricularis and Chryseobacterium gleum) can grow and form biofilms at very low nutrient condition as well as in chronic radioactivity. The bacterial isolates formed biofilm on SS-304L and glass. However, the biofilm parameters assessed by CLSM microscopy showed that the strains preferred SS-304L surface for biofilm formation. On SS-304L, the maximum biomass (0.45 l µm3/l µm2) was formed by S. arlettae when compared to maximum biomass (0.054 l µm3/l µm2) by Staphylococcus sp., on glass. Maximum biofilm thickness on SS- 304L was observed by Staphylococcus sp. (8.81 l µm) when compared to that of S. epidermidis (4.16 l µm) on the glass surface. The biofilm formation on SS-304L surface suggests the possible risk of microbial-induced corrosion of SNF pool cladding material. This study highlights the need for mandatory monitoring of microbial biofilm formation in an extreme environment such as SNF pool.

Isolation and characterization of culturable bacteria present in the spent nuclear fuel pool water.

A spent nuclear fuel (SNF) pool is a key facility for safe management of nuclear waste, where spent nuclear fuel rods are stored in a water pool. The spent fuel rods carry a significant amount of radioactivity; they are either recycled or stored for further processing. Pool water acts as a heat sink as well as a shield against the radiation present in spent/burned fuel rods. The water used in these pools is filtered by an ultra-filtration process which makes certain the purity of water. As the life span of these pools is approximately 20 to 40 years, the maintenance of pure water is a big challenge. A number of researchers have shown the presence of bacterial communities in this ultrapure water. The bacterial types present in SNF pool water is of increasing interest for their potential bioremediation applications for radioactive waste. The present study showed the isolation of six bacterial species in the SNF pool water samples, which had significant radio-tolerance (D10 value 248 Gy to 2 kGy) and also biofilm-forming capabilities. These strains were also investigated for their heavy metal removal capacity. Maximum biofilm-mediated heavy metal (Co and Ni) removal (up to 3.8 µg/mg of biomass) was observed by three isolates (FPB1, FPB4, and FPB6). The ability of these bacterial isolates to survive in radioactive environments can be of great interest for remediation of radioactive contaminants.

Biomarker for Cancer: A great Promise for Future.

Cancer is an uncontrolled growth of a cell due to failure in the cell growth signaling system. Cure of cancer is done only by the complete removal of cancerous cells from the body, the process may sound simple but its implementation is almost impossible. There are number of problems regarding its treatment such as its early detection. Science is progressing every second and so are our expectations. This review is about present scenario and future promises about the development of biomarkers. It is a big challenge whose completion will be beneficial in the early detection of cancer. As early detection is half victory in any disease, especially cancer, this kind of research will be advantageous in the field of cancer treatment.