Effect of the interrupted adaptation to D-methionine on the efficiency of Rhizobium meliloti strains

✍ Scribed by Hamdi, Yousef A.

• Publisher: Springer-Verlag
• Year: 1968
• Weight: 221 KB
• Volume: 63
• Category: Article
• ISSN: 0003-9276
• DOI: 10.1007/bf00412839

✦ Synopsis

meliloti strains 107-1, 111 and 152 were adapted to D-methionine in three ways: a) consecutive transfer in the presence of increasing amounts of ])-methionhle, b) alternate transfer between ~)-and L-methionine-containing media followed by final cultivation in the presence of each isomer, c) alternate transfer between D-methionine and medium 79 followed by cultivation in medium 79 or in I)-methionine-medium. At the end of the experiment efficiency of the strains was ascertained by a plant test.

Strain 111 lost efficiency when it was adapted consecutively to 0.125~ D-me. thionine or alternated between D-methionine and either L-methionine or medium 79-Strain 107-1 sucessively adapted to D-methionine lost efficiency within 16 weeks. On adaptation to D-methioninc alternated with L-methionine, efficiency was retained in L-methionine medium and lost in D-methionine medium. On alternate adaptation between D-methionine and medium 79, strain 107-1 lost efficiency in the D-methionine-medium but not in medium 79. Efficiency of strain 152 was lost by adaptation to 0.125~ D-methionine, but it was maintained on the alternate adaptation between ])-methionine and L-me~hionine or medium 79.