Type II glyoxalase that catalyzes the hydrolysis of (R)-S-lactoylglutathione to (R)-lactate and glutathione (PubMed:25670698, PubMed:17196158). Is more efficient than the isozyme GloC, and plays a major contribution to methylglyoxal (MG) detoxification in E.coli (PubMed:25670698). The two isoenzymes have additive effects and ensure maximal MG degradation (PubMed:25670698). an S-(2-hydroxyacyl)glutathione + H2O = a 2-hydroxy carboxylate + glutathione + H(+) (R)-S-lactoylglutathione + H2O = (R)-lactate + glutathione + H(+) Binds 2 Zn(2+) ions per subunit. Mn(2+) and Co(2+) can substitute for zinc in reconstitution experiments. Is inhibited by Cu(2+). kcat is 53 sec(-1) for the hydrolysis of (R)-S-lactoylglutathione (PubMed:17196158). kcat is 15.6 sec(-1) for the hydrolysis of (R)-S-lactoylglutathione (PubMed:25670698). Secondary metabolite metabolism; methylglyoxal degradation; (R)-lactate from methylglyoxal: step 2/2. Monomer. Cells lacking this gene show decreased methylglyoxal tolerance. A double deletion mutant lacking both gloB and gloC exhibits almost no resistance to exogenously supplied methylglyoxal, and is unable to grow at MG concentrations as low as 0.1 mM. Belongs to the metallo-beta-lactamase superfamily. Glyoxalase II family.