NTU Undergraduates' research April 2014 - Biosciences | Seite 43

Small colony variants of Pseudomonas aeruginosa do not seem to differ
phenotypically from their parent strain when observed outside of a biofilm
Michael M Lukumbuzya, School of Science and Technology Nottingham Trent University

Pseudomonas aeruginosa is one of the many bacterial species that have the ability to produce
biofilms. These biofilms have a host of functions ranging from protecting the bacteria to acquiring
nutrients. One of the more recently studied traits of biofilms is the diversification of the bacteria
into genetic variants that changes the overall behaviour of the biofilm. In this study we analysed
the differences of the small colony variants generated after they had gone back to planktonic
growth. They do not change in their individual cellular morphology and their biochemical profile
remains identical to that of the parent strain. In addition, there is no increase or decrease in the
small colony variants’ ability to resist antimicrobial agents. Furthermore, there are no differences
in the mutation frequency of the small colony variants and the parent strains. This data would
suggest that, although being morphologically different on agar, all the other phenotypic traits of
small colony variants only present themselves upon biofilm growth.