  In this paper, we consider partially commutative metabelian Lie algebras
whose defining graphs are cycles. We show that such algebras are universally
equivalent iff the corresponding cycles have the same length. Moreover, we give
an example showing that the class of partially commutative metabelian Lie
algebras such that their defining graphs are trees is not separable by
universal theory in the class of all partially commutative metabelian Lie
algebras.
