Doukara was hit with the suspension by the Football Association on Thursday over an incident in the second half of the 1-1 draw between Leeds and Fulham at Elland Road on February 23.
The Frenchman was accused of biting Amorebieta in the 54th minute and saw a charge of violent conduct upheld at an independent regulatory commission. Doukara had denied the claims against him.
His ban will come into immediate effect, ruling him out of United’s trip to Rotherham United on Saturday and forcing him to miss all but one of their nine remaining Championship games.
Doukara will return to contention for the club’s last fixture of the season at Preston North End on May 7.
On top of his suspension, he was fined £5,000 and warned about his future conduct.