9 research outputs found
Differential attraction and repulsion of Staphylococcus aureus and Pseudomonas aeruginosa on molecularly smooth titanium films
Magnetron sputtering techniques were used to prepare molecularly smooth titanium thin films
possessing an average roughness between 0.18 nm and 0.52 nm over 5 μm × 5 μm AFM scanning
areas. Films with an average roughness of 0.52 nm or lower were found to restrict the extent
of P. aeruginosa cell attachment, with less than 0.5% of all available cells being
retained on the surface. The attachment of S. aureus cells was also limited on films
with an average surface roughness of 0.52 nm, however they exhibited a remarkable propensity
for attachment on the nano-smoother 0.18 nm average surface roughness films, with the
attachment density being almost twice as great as that observed on the nano-rougher film.
The difference in attachment behaviour can be attributed to the difference in morphology of
the rod-shaped P. aeruginosa compared to the spherical S. aureus cells
Enzymatic Depilation of Animal Hide: Identification of Elastase (LasB) from Pseudomonas aeruginosa MCM B-327 as a Depilating Protease
Conventional leather processing involving depilation of animal hide by lime and sulphide treatment generates considerable amounts of chemical waste causing severe environmental pollution. Enzymatic depilation is an environmentally friendly process and has been considered to be a viable alternative to the chemical depilation process. We isolated an extracellular protease from Pseudomonas aeruginosa strain MCM B-327 with high depilation activity using buffalo hide as a substrate. This 33 kDa protease generated a peptide mass fingerprint and de novo sequence that matched perfectly with LasB (elastase), of Pseudomonas aeruginosa. In support of this data a lasB mutant of MCM B-327 strain lacked depilatory activity and failed to produce LasB. LasB heterologously over-produced and purified from Escherichia coli also exhibited high depilating activity. Moreover, reintroduction of the lasB gene to the P. aeruginosa lasB mutant via a knock-in strategy also successfully restored depilation activity thus confirming the role of LasB as the depilating enzyme