sentence: 4 The enzymes can be divided into four types , including biphenyl dioxygenase ( BphA ) , dihydrodiol dehydrogenase ( BphB ) , 2,3 - dihydroxybiphenyl dioxygenase ( BphC ) and hydrolase ( BphD ) .5 , 6 , 7 , 8, 9 , 10 , 11We previously investigated the distribution of PCB-utilizing bacteria in Shanghai .