 For this reason, "Acetobacter aceti" has become a valuable resource for understanding the mechanisms by which proteins can attain acid stability.Studies of proteins adapted to low pH have revealed a few general mechanisms by which proteins can achieve acid stability.In most acid stable proteins (such as pepsin and the soxF protein from "Sulfolobus acidocaldarius"), there is an overabundance of acidic residues which minimizes low pH destabilization induced by a buildup of positive charge.