| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2001: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2000: ¥2,500,000 (Direct Cost: ¥2,500,000)
|
|---|
| Research Abstract |
Bacillus sp.JFS is thermophilic bacterium capable of degrading PCB. bphCgene encoding 23DHBPDO had been cloned from Bacillus sp. JF8.bphA.bphB, and bphD are sown to be located upstream of bpcC gene, and they are cloned and sequenced. bphR, bphD, bphA1, bphA2, and bphB genes were present upper stream of bphC. On the other hand, bphE, bphG, bphF genes were located downstream of bphC. Amino acid sequence ofBphAhad good similarity to known BphAofmethophilic PCB-degrading bacteria. However, BphD had similarity (about 35%) to XylF and TodEwhich are used in the monocyclic hydrocarbon degradation and had lower homology (about 20%) to BphD proteins responcible for the degradation ofPCB. This character ofBphD have tendency to that ofBphC.Interestingly, IS sequence and transposase were present upstream ofbphR and this result shows that these PCB-<iegrading genes might be transferred from other microorganisms. N-terminal amino acid sequences of23DHBPDO and HOPDA, which are purified from Bacillus sp.JFS grown on biphenyl, were identical to those of deduced amino acid sequences from nucleotide sequence of these proteins. This result indicate that these two proteins are responsible for the degradation ofbiphenyl.
BphCand BphD proteins have high stability toward temperature reflecting thermophilic bacterium, and toward inhibitors. BphC have broad substrate specificity, on the contrary BphD was specific for HOPDAnot for HMSAor HOHD. Both enzymes had low Km value (1/ 10) compared to mesophilic enzymes.Interestingly, BphChad Mn in theprotein instead ofFe, whichis used in 23DHBPDO of mesophilic bacteria.
|
