All of the following are true except-

Proteus does not form uric acid stones. Option 1 E. coli is an aerobe and facultative anaerobe. Option 2 Uric acid stone formation takes place in acidic urine. Proteus produces ammonia and contributes to alkalinity. It does not thus lead to formation of uric acid stones. The alkalinity leads to necrosis of renal tubular epithelium & precipitation of phosphate stones. Option 3 E. coli are motile by peritrichous flagella. Option 4 The distinctive character of Proteus genus is deamination of phenylalanine to phenylpyruvic acid (PPA test positive). Refer to the image below. - Green colour in test tube indicates PPA test positive.