gene variant mutant Hha24E9 variant of Hha colombos:hha_b0460.24E9_VARIANT PMID: 21255366 a gene variant mutant with one substitution: K62X. Hha24E9 decreases biofilm formation fourfold compared with wild-type Hha in E. coli BW25113 hha. Hha24E9 reduces biofilm formation by inducing acid resistance, glycerol-3-phosphate metabolism and phosphonate metabolism.