Induction of the viable but non-culturable condition in Xanthomonas campestris pv. campestris in liquid microcosms and sterile soil

Abstract

Xanthomonas campestris pathovar campestris was examined for the ability to enter the viable but non-culturable (VBNC) state. When nutrients were removed from a bacterial culture, the culturability dropped to undetectable levels within 6 weeks while the concentration of viable cells remained above 10(5) cells ml(-1). Addition of cupric sulfate facilitated this process. When bacteria were placed in autoclaved soil, culturability dropped by at least four logs within 5 days of the experiment while the concentration of viable cells remained at least two logs higher. These results indicate that the plant pathogen X. campestris can enter the VBNC condition in sterile soil and in liquid cultures and that cupric sulfate decreases the time for entry into the VBNC condition.