@article{mbs:/content/journal/micro/10.1099/00221287-132-7-1951, author = "Koizumi, Jun-Ichi and Min, Zhang and Imanaka, Tadayuki and Aiba, Shuichi", title = "Temperature-dependent Plasmid Integration into and Excision from the Chromosome of Bacillus stearothermophilus", journal= "Microbiology", year = "1986", volume = "132", number = "7", pages = "1951-1958", doi = "https://doi.org/10.1099/00221287-132-7-1951", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-132-7-1951", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", abstract = "Summary: A Transformant of Bacillus stearothermophilus carrying a recombinant plasmid, pLP11 (9.5 MDa), on which the penicillinase gene (penP) and kanamycin resistance gene (kan) were located was subjected to mutagenesis, and a mutant plasmid (9.5 MDa; penP kan), designated pTRA 117, 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 deteeted 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 1.2 MDa DNA fragment of the host chromosome, and this was confirmed by Southern hybridization. pTRZ90 (7.9 MDa; kan) was constructed from pTRZ117 by the deletion of a 2.8 MDa DNA fragment that contained penP. Fresh transformants of B. stearothermophilus that carried either pTRZ117 or pTRZ90 could grow at 65 °C.", }