| Budget Amount *help |
¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 1987: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1986: ¥2,800,000 (Direct Cost: ¥2,800,000)
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| Research Abstract |
A transformant of Bacillus stearothermophilus carrying a recombinant plasmid,pLP11(9.5MDa), on which the penicillinase gene (penP)and kanamycin resistance (Kan)were located was subjected to mutagenesis,and a mutant plasmid(9.5MDa;penP kan),designated pTRA117,was obtained.A transformant of B.stearothermophilus carrying pTRA117 could grow at 63゜C in medium containing kanamycin,whereas a transformant carrying pLP11 could not. Although pTRA117 was detected as covalently closed circular(ccc)DNA when it was extracted from transformants cultured at 48゜C,it was integrated into the host chromosome when the culture temperature was shifted up to 63゜C.If the culture temperature was lowered to 48゜C from 63゜C,a new plasmid (10.7 MDa;penP kan),designated pTRZ117,could be detected as ccc DNA;the size of this plasmid suggested that it was pTRA117 plus a 1.2MDa DNA fragment of the host chromosome,and this was confirmed by Southern hybridization.pTRZ90(7.9MDa; kan) was constructed from pTRZ117 by the deletion of a 2.8 MDA fragment that contained penP. Fresh transformants of B.stearothermophilus that carried either pTRZ117 or pTRZ90 could grow at 65゜C.
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