PURPOSE: Extremely compact plasmid pSL1 having a large number of copies suitable as a vector useful for gene recombination using Streptococcus lactis as a host, obtained from Streptococcus lactis.
CONSTITUTION: Plasmid pSL1 of duplex DNA having 1.74+0.2×106 dalton (about 2.6 kilo base), number of scission site by restricted enzyme and molecular weight of scission fraction (×106 dalton) of EcoR I 1(1.74), Hinf I 4(0.85, 0.69, 0.16, 0.07), HaeII 2(0.91, 0.83), EcoR I +Hinf I 5(0.69, 0.59, 0.21, 0.16, 0.07). Streptococcus lactis No128(FERMP-6666) separated from a great number of strains belonging to Streptococcus lactis is cultivated by settled culture in a common lactic acid bacteria medium at 20W40°C for 15W30hr, the prepared culture is centrifuged to collect a mold, which is washed, subjected to bacteriolysis, and purified to give plasmid pLS1.
KANEKO SHIYOUHEI
KANBE MICHIO
EBISAWA NAOYUKI
