I've been comparing the growth of recombinant enzyme-bearing E. coli and P. putida with their native counterparts. Contrary to expectation, the recombinant bacteria outgrow their native counterparts. The only difference was the inclusion of antibiotic and inducing agent in the culture of the recombinant cells.
What possibly could make a recombinant bacteria outgrow its native counterpart? Any reason and reference will be appreciated.
Thank you!
was your enzyme expressed as soluble protein or as inclusion bodies? I
It may be if the recombinant organisms are more fitter than the native ones. I would like to know about what recombinations have been done?
may be your growth conditions are not optimal for the native bacteria and are better for the recombinants, excess antibiotic used as C source?
@Alexandra Johnson, the enzymes were cellulases and the inducer was L-arabinose
@Alemu Tekewe , the enzymes were displayed (attached) on the surface of the bacteria.
@Sourav Maiti, the only critical alteration was the use of maximized autotransporter expression (MATE) system for the expression and display of the enzyme (passenger protein) on the surface of the bacteria.
@Herve Levesque, the E. coli (both native and recombinant) were cultured at 37 oC whereas that of P. putida was at 30 oC. These two reference temperatures are the most reported optimum temperatures for the respective bacteria.
This could be explaining. Pseudomonas are famous for multiple enzymes and these make them to survive in all conditions. Perhaps this new recombination has produced one fitter strain. If pathogenicity islands could be deleted, these can well be a weapon to be utilized as preventive measure for colonization by pathogenic strains by the principle of competition.
Most protein production strains of E. coli have the arabinose operon intact and will use it as a carbon source. E. coli generally loves simple carbohydrates and will grow really rapidly and to higher densities in complex media if you add a sugar it can digest. I don't know if P. putida can digest arabinose though.
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