For the screening of siderophore biosynthesis-defective mutants, Pseudomonas sp. PY002 cells were mutagenized with transposon Tn5 harbored in a plasmid, pRZ102. Mutants defective in the biosynthesis of the yellow-green-fluorescent siderophore
were
screened under iron limitation condition. From the screening, finally 32 mutants were isolated on CAS and/or MKB agar plate containing 500μM of dipyridyl and/or 1 mg/ml of ethylene di(o-hydroxypheny1 acetic acid). On the plate, the mutant MP128
was
isolated neither produce siderophore nor exhibit fluorescent To identify siderophore-producing clones, MP128 was (Flu-/Sid-) was complemented by using triparental conjugation method. From the complementation experiments, pCOM97 was able to
exhibit
Flu+/Sid+ phenotype. The restriction map of insert DNA from the pCOM97 was constructed using the restriction enzymes such as EcoRⅠ, HindⅢand XhoⅠ. By subcloning, it was revealed that HindⅢand XhoⅠfragment (3 kb) of pCOM97 could complement
siderophoredefective mutant MP128.
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