COMPARISON OF ENZYMATIC AND IMMUNOCHEMICAL PROPERTIES OF 2,3-DIHYDROXYBIPHENYL-1,2-DIOXYGENASES FROM 4 PSEUDOMONAS STRAINS

A 2,3-dihydroxybiphenyl-1,2-dioxygenase gene has been cloned from chro mosomal DNA of Pseudomonas sp. DJ-12 which tan grow on biphenyl or 4-c hlorobiphenyl as the sole carbon and energy source. Enzymatic and immu nochemical properties of the cloned 2,3-dihydroxybiphenyl-1,2-dioxygen ase were characterized, and compared with those of P. pseudoalcaligene s KF707, Pseudomonas sp. KKS102, and P. putida OU83. The dioxygenase o f Pseudomonas sp. DJ-12 was similar to those of P. pseudoalcaligenes K F707, and Pseudomonas sp. KKS102, but significantly different from tha t of P. putida OU83 in electrophoretic mobilities on native PAGE and S DS-PAGE. The dioxygenases of Pseudomonas sp. DJ-12 and P. putida OU83 exhibited the highest ring-fission activity to 3-methylcatechol, and t hose of P. pseudoalcaligenes KF707 and Pseudomonas sp. KKS102 to 2,3-d ihydroxybiphenyl among 2,3-dihydroxybiphenyl, catechol, 3-methylcatech ol, 4-methylcatechol, and 4-chlorocatechol as substrates. 2,3-dihydrox ybiphenyl-1,2-dioxygenase of P. pseudoalcaligenes KF707 was immunochem ically related to that of Pseudomonas sp. KKS102, but was different fr om those of Pseudomonas sp. DJ-12 and P. putida OU83.