Doctoral Student
Molecular Engineering Research Group (ENGMOL)
Universitat Politècnica de Catalunya (UPC)

G1, ETSEIB, UPC Campus Diagonal Sud
Avinguda Diagonal 647, Barcelona, Spain - 08028
Email: jenifar.das at upc.edu

Bacteria generally produce pigments (light-absorbing compounds) in their lifecycle for survival. Pigments have vast industrial and medical applications, such as organic food colourants, textiles colourants, fluorescence-based indicators, etc. This work assessed Arctic stone samples with pigmented spots to isolate and identify pigment-producing bacteria. We have isolated five potential pigment-producing bacterial strains. Our study confirmed that four bacterial strains have the potential to produce pigments (1^st strain produces yellow pigment, 2^nd strain produces red pigment, 3^rd strain produces pink pigment, and the 4^th strain produces cream coloured pigment). We optimised the conditions such as growth medium (nutrient broth), temperature (25℃) and pH (alkaline) for the growth of the strains and the production of pigments. The morphology of bacterial cells was identified using different microscopes. The pigments were extracted by solvent extraction and analysed by scanning the absorbance with a UV-Vis spectrophotometer. Then the strains were characterised using different biochemical tests and 16S rDNA sequencing.

Pseudomonas aeruginosa is one of the most frequently found bacterial pathogens in patients with chronic infections, such as chronic wounds, cystic fibrosis, etc. The persistence of P. aeruginosa in these infections is enabled by its ability to form biofilms. Standard antibiotic treatments that are effective against bacteria living as single cells are generally unsuccessful against biofilms. Understanding the physiological adaptations of bacterial biofilms will make it possible to design specific countermeasures and treatments for biofilm-based persistent infections. In this work, we investigated conditions underlying biofilm formation using parameters such as time, cell numbers, etc. We observed that the quantity of biofilm content increases with time and cell number. Our analysis provides insights into the conditions in which P. aeruginosa regulates its metabolism to synthesise molecules that are important for biofilm formation. Based on these insights, we conclude that a new cell signalling pathway may be targeted to develop anti-biofilm drugs.

Wound healing is the process by which skin and other body tissue repair themselves after injury. The temperature of the wound bed optimal for healing lies between the range of 33 and 42 ℃. Wound healing is delayed when the temperature is below or above this range. Thus there is a necessity for a device that accurately and continuously monitors the temperature of the wound. We made a device using an LM35 temperature sensor, an analog data logger, a rechargeable battery, a USB flash drive and some connecting wires. The device was tested first with cold water in a beaker and then on the intact skin of a human subject. The data was stored and interpreted using MS Excel. A graph was plotted to show the variations in temperature with time. This data logger can continuously measure the temperature at the wound bed, which could help optimise the healing process.