Development of A Genetic Manipulation System and Screening of Magnetosome Deleted Mutants for Magnetospirillum gryphiswaldense
趋磁螺菌遗传操作体系的建立及磁小体缺失突变株的筛选

Progress in the genetic analysis of the mechanism of magnetosome biosynthesis in Magnetospirillum gryphiswaldense MSR 1 has been hampered by the lack of an appropriate genetic manipulation system and its antibiotic resistant mutants. Here reported on the establishment of a genetic manipulation system that can be used more readily than that of the others for Magnetospirillum. This system included method of solid medium plate enveloped with Parafilm to form colony, conjugational gene transfer in a selective medium, screening the nonmagnetic mutants by magnet adsorption technique. Two magnetosome deleted mutants were constructed by conjugative transposon mutagensis and the application of this genetic system. This system and the two nonmagnetic mutants will be very useful in study of the molecular mechanism of magnetosome biosynthesis in magnetotactic bacteria.