  Subgraph enumeration problems ask to output all subgraphs of an input graph
that belongs to the specified graph class or satisfy the given constraint.
These problems have been widely studied in theoretical computer science. As
far, many efficient enumeration algorithms for the fundamental substructures
such as spanning trees, cycles, and paths, have been developed. This paper
addresses the enumeration problem of bipartite subgraphs. Even though bipartite
graphs are quite fundamental and have numerous applications in both theory and
application, its enumeration algorithms have not been intensively studied, to
the best of our knowledge. We propose the first non-trivial algorithms for
enumerating all bipartite subgraphs in a given graph. As the main results, we
develop two efficient algorithms: the one enumerates all bipartite induced
subgraphs of a graph with degeneracy $k$ in $O(k)$ time per solution. The other
enumerates all bipartite subgraphs in $O(1)$ time per solution.
