Antibiotic resistant mutant - Antibiotic resistance in plant groth promoting bacteria. (Nov/17/2005 )

I have developed antibiotic resistance in some plant growth promoting bacteria like one Azospirillum species, one Phosphate solubilising bacteria(Bacillus pentathenicum) and one Azotobacter strain. And I got that the mutant strains produce more hormone(IAA) than the wild type. The nitrogenase enzyme actrivity also increase in both the Azospirillum & Azotobacter strain.
So I can conclude from my experiment that these mutant strains are more beneficial than the wild type strain. So, we can use as an useful biofertilizer agent.
I want to discuss in detail about my research work.
Thanking you
Dipnarayan

In what way are the strains mutant? Did you insert a chromosomally encoded antibiotic resistance gene into them, or is it plasmid borne, or did you select for spontaneous resistance? What antibiotic(s) are the strains resistant to? Do you know if the increase in enzyme production occurs in natural situations, or only in the laboratory setting? Is the growth rate of the mutants affected?