  Let $(\mathcal{M}, Q)$ be a dg manifold. The space of vector fields with
shifted degrees $(\mathcal{X}(\mathcal{M})[-1], L_Q)$ is a Lie algebra object
in the homology category
$\mathrm{H}((C^{\infty}_{\mathcal{M}},Q)\mathrm{-}\mathbf{mod})$ of dg modules
over $(\mathcal{M},Q)$, the Atiyah class $\alpha_{\mathcal{M}}$ being its Lie
bracket. The triple $(\mathcal{X}(\mathcal{M})[-1], L_Q; \alpha_{\mathcal{M}})$
is also a Lie algebra object in the Gabriel-Zisman homotopy category
$\Pi((C^{\infty}_{\mathcal{M}},Q)\mathrm{-}\mathbf{mod})$.
  In this paper, we describe the universal enveloping algebra of
$(\mathcal{X}(\mathcal{M})[-1], L_Q; \alpha_{\mathcal{M}})$ and prove that it
is a Hopf algebra object in
$\Pi((C^{\infty}_{\mathcal{M}},Q)\mathrm{-}\mathbf{mod})$. As an application,
we study Fedosov dg Lie algebroids and recover a result of Sti\'enon, Xu, and
the second author on the Hopf algebra arising from a Lie pair.
