Now that’s a title of a paper for you. I confess, it baffled me. At a minimum, I had to look up disproportionation. What is it? Also known as dismutation, this refers to a redox reaction in which a compound that is partly oxidized converts to two compounds, one of higher and one of lower oxidation state. In the sulfur business, compounds become simultaneously reduced and oxidized to sulfide and sulfite. Disproportionable (a term I just coined) sulfur compounds are abundant in the ocean and especially near hydrothermal vents. So are the bacteria that can carry out these reactions. Some 30 species that can do this are known and they use a variety of enzymes in these processes. The importance of these in their environment remains to be determined, but they are likely to be quite relevant to the complex sulfur cycles in the oceans.
Now for the rest of the title. Exergonic, as you likely know, means that a process is accompanied by the release of energy. The title is now crystal clear, no?