Maia M, Sanchez J M, Vela G R
Department of Biological Sciences, North Texas State University, Denton 76203.
J Bacteriol. 1988 Apr;170(4):1984-5. doi: 10.1128/jb.170.4.1984-1985.1988.
Four laboratory strains and two isolates of Azotobacter vinelandii were found to contain plasmids. Twenty-five laboratory strains which could fix nitrogen did not have free, covalently closed circular plasmid DNA. The plasmids varied in size from 9 to 52 megadaltons, and each strain yielded only one plasmid. No discernible differences in ability to fix nitrogen were found between plasmid-bearing and cured cultures.
发现四株实验室菌株和两株维涅兰德固氮菌分离株含有质粒。二十五株能够固氮的实验室菌株没有游离的、共价闭合环状质粒DNA。这些质粒大小从9到52兆道尔顿不等,并且每个菌株只产生一种质粒。在含有质粒的培养物和去除质粒的培养物之间,未发现固氮能力有明显差异。