[Organotrophic growth and the synthesis of an autoregulatory factor in Pseudomonas carboxydoflava]

The organotrophic growth of Pseudomonas carboxydoflava Z-1107 was studied in media limited or non-limited with respect to carbon and nitrogen sources. The organotrophic growth was found to decelerate not only when carbon and nitrogen sources were exhausted but also when their content was high enough. At all of the growth phases, P. carboxydoflava could synthesize butanol-soluble substances capable of inhibiting the respiration and growth of the microorganism (the autoregulator factor d) and release them into the cultural broth. The dynamics of accumulation of the factor d in the cultural broth was determined using an arbitrary criterion (the inhibition of respiration in the control culture). The authors discuss a possibility to explain the deceleration of P. carboxydoflava organotrophic growth in a medium which is not limited with carbon and nitrogen sources in terms of the accumulation of the factor d in the culture, as well as possible reasons for the absence of a direct correlation between the activity of the factor and the growth rate of the culture.