3.4.21.B50 D113A mutant exhibits 97.5% reduction in activity 690548 3.4.21.B50 H83A mutant exhibits 93.4% reduction in activity 690548 3.4.21.B50 additional information engineering of a xylose-inducible DegQ strain SQR9XYQ to improve the biocontrol activity. In this strain, the phosphorylation of DegU can be gradually activated by xylose, and biofilm formation, antibiotic expression, colonization activity, and biocontrol efficiency are improved compared with the wild-type strain -, 775034 3.4.21.B50 S187A protease-deficient mutant that retains chaperone-like activity 718408 3.4.21.B50 S188A mutant exhibits 91.8% reduction in activity 690548