Effect of Bas2108-2109 Two Component System on Multicellular Behavior of Bacillus anthracis

Bacillus anthracis, a threating bioterror agent causing anthrax
is endowed with 41 Two-Component Systems (TCS). TCS in
B. anthracis shares significant similarity with TCS present in Bacillus
subtilis. We have recently reported BAS2108-2109 TCS as an
ortholog of DegUS TCS and it was shown to be important in the
regulation of proteases in B. anthracis. DegUS TCS have been
implicated for their role in the regulation of multicellular behavior
in other bacteria. In this study, the role of BAS2108-2109 TCS in
regulating multicellular behavior in B. anthracis was investigated.
B. anthracis overexpressing BAS2109 was found to exhibit retarded
swarming motility, biofilm and pellicle formation indicating its role
in complex colony formation. Overexpression of BAS2109 also
augmented sporulation in B. anthracis, although it reduced spore
germination. Invasion and adherence of the B. anthracis overexpressing
BAS2109 was higher as compared to the wildtype,
further suggesting the role of this system in the pathogenesis of
B. anthracis. Together, our results demonstrate the role of BAS2108-
2109 in controlling various multicellular behavioral responses in
B. anthracis.