Abstract: A plasmid pOA15 in isolated form having the property of conferring pock-forming ability on Streptomyces griseus (ATCC 10137) and a molecular length of about 10 kb, and showing such sensitivity that(a) it has one restriction site recognized by BamHI,(b) it has one restriction site recognized by EcoRI,(c) it has 7 restriction sites recognized by SalI, and(d) it is not cleaved by BglII, HindIII, KpnI, PstI and XbaI,and a biologically pure culture of a microorganism containing the above plasmid.

Abstract: A power steering apparatus comprises a housing, a gerotor mechanism having a rotor and a stator, and a rotary valve mechanism constituted by a rotary spool disposed within the central interior of the housing and connected to the rotor of the gerotor mechanism and a rotary sleeve freely rotatably attached to the outside of the rotary spool so as to allow insertion of the rotary spool thereinto. Rotation of the sleeve relative to the spool due to a steering operation switches over the flow paths for pressurized liquid to the gerotor mechanism to thereby rotate the rotor of the gerotor mechanism in the direction corresponding to the steering operation. The pressurized liquid in an amount proportional to the degree of the steering operation is supplied from the liquid chambers of the gerotor mechanism contracted by the rotation of the rotor to actuators of a steering mechanism.