Isolation and growth of rhizobia

This chapter describes basic techniques for the isolation and growth of rhizobia, some of which have been used for more than a century. While these techniques re¬tain their importance, the success of current and future rhizobiology studies and enterprises will depend on the training, skills and techniques described in this chapter. A note of caution: nodules (particularly those collected from the field) are not always occupied by a single rhizobial isolate nor even by a single micro-or¬ganism. Nodules of pea and lupin, for example, have been described as containing both the nitrogen-fixing symbiont and associative organisms such as Micromono¬spora (Trujillo et al. 2010). Hence, we must be prepared for a range of organisms to appear on growth plates during isolation procedures. Recognition of rhizobia when growing on a solid medium is an essential skill in rhizobiology