%0 Journal Article %A Pankhurst, C. E. %T Ineffective Rhizobium trifolii Mutants Examined by Immunediffusion, Gel-electrophoresis and Electron Microscopy %D 1974 %J Microbiology, %V 82 %N 2 %P 405-413 %@ 1465-2080 %R https://doi.org/10.1099/00221287-82-2-405 %I Microbiology Society, %X Summary: Antigens of 32 ineffective, antibiotic-resistant or antimetabolite-resistant mutants from two effective parent strains of Rhizobium trifolii (t1 and t42) were cross-reacted with antiserum prepared against the parent and six other strains of R. trifolii. Fifteen of the mutants were compared with the parent strains by gel- electrophoresis of soluble and cell envelope (bacterial wall plus plasma membrane) proteins and structural examination of nodules. Six mutants of t1 and three mutants of t42 appeared to have an altered cell envelope and released internal antigens more readily from intact rhizobia than did the parent strains. The same six mutants of t1 formed tumour-like growths on Trifolium pratense roots which contained no infection-threads or rhizobia. The three mutants of t42 formed ineffective nodules which differed in structure. Ineffective nodules produced by the other mutants were defective at various stages of development. No qualitative differences in soluble or cell envelope proteins were found between mutants and parent strains, but the cell envelope fraction of some mutants differed quantitatively. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-82-2-405