  In this note we give an explicit formula for the preserved Killing spinors in
deformed string theory backgrounds corresponding to integrable Yang--Baxter
deformations realized via (sequences of) TsT transformations. The Killing
spinors can be expressed only in terms of the bi-vector $\Theta$ which encodes
the deformation. This formula is applicable to deformed backgrounds related to
$r$-matrices of various ranks, including those that do not satisfy the
unimodularity condition and give rise to backgrounds in generalized
supergravity. We conjecture that our formula also remains valid for integrable
deformations which are not realized via TsT transformations and motivate this
conjecture by explicit examples.
