Background: In recent years, Antarctica has become a key source of biotechnological resources. Native
microorganisms have developed a wide range of survival strategies to adapt to the harsh Antarctic environment,
including the formation of biofilms. Alginate is the principal component of the exopolysaccharide matrix in
biofilms produced by
Pseudomonas, and this component is highly demanded for the production of a wide
variety of commercial products. There is a constant search for efficient alginate-producing organisms.
Results: In this study, a novel strain of
Pseudomonas mandelii isolated from Antarctica was characterized and found
to overproduce alginate compared with other good alginate producers such as
Pseudomonas aeruginosa
and
Pseudomonas fluorescens
. Alginate production and expression levels of the alginate operon were highest at 4°C.
It is probable that this alginate-overproducing phenotype was the result of downregulated MucA, an anti-sigma
factor of AlgU.
Conclusion: Because biofilm formation is an efficient bacterial strategy to overcome stressful conditions, alginate
overproduction might represent the best solution for the successful adaptation of
P. mandelii to the extreme
temperatures of the Antarctic. Through additional research, it is possible that this novel
P. mandelii strain could
become an additional source for biotechnological alginate production.
