g mgso4 7h20 0 3 g nahco3 0 1 g cacl 2 2 h20 0 03 g ferric ammonium citrate and 2 ml microelement solution with shaking at 150 rpm the microelement solution was produced by adding 0 556 g feso4 7h20 0 396 g mncl2 4h20 0 034 g cucl 2 2 h20 0 06 g h3bo3 0 006 g namoo4 2h20 0 562 g coso4 7h20 0 058 g znso4 7h20 and 0 004 g nicl2 6h20 to 200 ml of 0 5n hydrochloric acid when required antibiotics such as 100 u03bcg ml ampicillin 20 u03bcg ml kanamycin and 34 u03bcg ml chloramphenicol were added to the growth media standard dna manipulation techniques were used plasmid dna was prepared using miniprep extraction kit restriction enzymes and t4 dna ligase were purchased from new england biolabs polymerase chain reactions pcr using taq dna polymerase invitrogen were performed according to the manufacturer 39 s protocol oligonucleotide primers were purchased from genotech korea dna was sequenced using bigdye terminator sequencing kit applied biosystems on an automated dna sequencer model 310 perkin elmer transposon mutants were generated by conjugating p fluorescens bm07 with e coli s17 1 carrying the mariner transposon vector pkgl3 as follows recipient p fluorescens.