6 Genetic Methods in Clostridia

Publisher Summary Owing to the extreme diversity of the genus, the gene transfer methods described in this chapter will probably require optimization, refinement and even further development, for use with organisms and strains other than those for which they were specifically devised. It is worth stressing that in any experiment involving gene transfer to clostridia, the physiological state of the recipient is of cardinal importance. Since gene transfer frequencies are generally rather low (often below 10" per recipient), the methods and media employed must allow recovery of as many potential transformants or trans-conjugants as possible. Optimal survival of the recipient is of the utmost importance. Brief exposure to oxygen during manipulation at the laboratory bench may be perfectly acceptable for isolating and routinely subculturing some of these obligately anaerobic organisms, but this is usually a recipe for failure when attempting gene transfer. Unless the organism under investigation is unusually tolerant of exposure to oxygen, all manipulations should be carried out in an anaerobic workstation.