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Aims To investigate the molecular basis of biofilm formation in a recombinant lab strain of Deinococcus radiodurans with a plasmid harbouring gfp and kanR that acquired the biofilm-forming ability. Methods and results Deinococcus radiodurans R1 is known as a nonbiofilm former bacterium and so far there are no reports on its biofilm-producing capabilities. In this study, we investigated the molecular basis of biofilm formation in a recombinant strain of D. radiodurans using classical biofilm assays, confocal laser scanning microscopy and real-time PCR. Biochemical analysis of D. radiodurans biofilm matrix revealed that it consisted predominantly of protein and carbohydrate complexes with a little amount of extracellular DNA (eDNA). Furthermore, studies showed that D. radiodurans biofilm formation was enhanced in the presence of 25 mM Ca2+, which enhanced the exopolysaccharide and protein content in the biofilm matrix. Enzymatic treatments with proteinase K, alginate lyase and DNase I indicated the involvement of some proteinaceous components to be critical in the biofilm formation. RT-PCR studies showed that increased expression of a surface layer protein SlpA conferred the biofilm ability to D. radiodurans. Conclusion Overexpression of SlpA in D. radiodurans conferred the biofilm formation ability to the bacterium, in which a partial role was also played by the recombinant plasmid pKG. It was also shown that the presence of Ca2+ in the growth medium enhanced SlpA production, thus improving biofilm stability and biofilm maturation of D. radiodurans. Significance and Impact This study shows how biofilm formation can be augmented in D. radiodurans. The finding has implications for the development of D. radiodurans biofilm-based biotechnological applications.

In this study, a comprehensive in silico characterization was performed on Bap-family proteins to develop novel approaches to deal with Staphylococcus biofilms with a better understanding of the functional, structural, and topological features of Bap proteins. This study showed that Bap-like proteins in staphylococci are highly acidic, large, and cell-wall anchored proteins with tandem repeats. Structurally, Bap-family proteins have two distinct parts. N terminal part, which contains at least 2-3 calcium-binding EF-hand motifs that play a regulatory role in Bap functioning. Whereas the C-terminal part which predominantly consists of tandem repeats (TR), plays a functional as well as structural role. Bioinformatic analysis of Bap proteins and other homologous proteins revealed the presence of an amyloidogenic heptapeptide (STVTVTF) in the hydrophobic core of TRs of protein, responsible for the protein-protein interactions. The synthetic heptapeptide was tested if the masking effect on surface proteins could inhibit the S. aureus biofilm development and act as an 'antibiofilm-peptide'. The results clearly showed that the heptapeptide was able to inhibit early adhesion as well as biofilm development in the S. aureus biofilms. This approach has a promising potential to treat persistent biofilm-based S. aureus infections where Bap-like proteins do play a significant role.

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 μm

Deinococcus radiodurans is the most radiation-tolerant organism ever known. It has gained importance in recent years as a potential candidate for bioremediation of heavy metals, especially the radioactive type. This study investigates the efficiency of a recombinant D. radiodurans (DR1-bf

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 (D

Background: Food colors are used to give an attractive appearance to food articles. Food colors are categorized as permitted and non-permitted colors. Use of non-permitted food colors has led to loss of real quality of food. Adulteration of food products is a cause of concern these days. Objective: The objective was to detect the presence of non-permitted food colors in edibles using preliminary color test and thin layer chromatography. Materials and methods: Four types of samples i.e. turmeric, jelly, green peas and namkeen were collected from different locations for analysis. 20 samples of each were collected from different locations to be analysed for adulteration with most commonly used food colors i.e metanil yellow and malachite green. Non permitted food colors in collected edibles were detected using preliminary color test and thin layer chromatography. Results: The colour change and Rf values of the test samples were analysed and it was observed that 46% of food products tested were adulterated with metanil yellow whereas adulteration with malachite green was about 44% of the tested samples. Conclusion: The used methods of detection can be used in the area of food quality control to detect such harmful and banned colors in edibles without massive instrumentation.