Wild-type bacterium

Interestingly, it has been reported that common bean plants inoculated with a phaC mutant of R. etli show an increased nitrogen-fixation capacity and enhanced growlh in comparison with plants inoculated with the wild-type bacterium (CevaUos et al. 1996). An important difference between S. meliloti and/ , etli is that in the former. 

Unlike selenium there is no required biological role for tellurium in bacteria or plants that has been determined however, this may ultimately not be the whole story.111 Selenium was only viewed as a toxic metalloid with no necessary role for metabolism until at least the 1950s see above. While tellurite is less soluble than tellurate in aqueous solution, in general tellurite is probably more toxic to most organisms.190 The non Te-resistant wild type E. coli bacterium (Gramnegative) has MICs of 1 to 3 ppm for tellurite and tellurate.144,191,192 Tellurite is used to enrich and select for Staphylococcus aureus.169,193,194... 

The earliest work with this bacterium showed that PolyPs occurred in it in extremely low amounts, if at all, and were present not continually and often under specific conditions, usually under growth limitation by some nutrient sources. Indeed, study of the dynamics of PolyP accumulation during the growth of the wild-type strain E. coli K12 on a mineral... 

Scrutton, N. S., Packman, L. C., Mathews, F. S., Rohlfs, R. J., and Hille, R., 1994, Assembly of redox centers in the trimethylamine dehydrogenase of bacterium WjA,. Properties of the wild-type enzyme and a C30A mutant expressed from a cloned gene in Escherichia coli, J. Biol. Chem. 269 13942913950. 

The low-temperature kinetics data of these early difficult experiments did not have the time or spectral resolution to consider these possibilities. However, there is now an excellent set of temperature-dependent kinetics data for the similar bacterium Rp. viridis [16, 17]. These data clearly show multiphasic kinetics that can be resolved into very fast, fast and slow phases, most of which slow with temperature roughly an order of magnitude before reaching a temperature-independent plateau. What does change dramatically with temperature is the contribution of each of these phases, with the fast phases falling away dramatically at a temperature around 210 K for the wild-type Rp. viridis. Thus, the overall result is a dramatic decrease in half-time of the reaction with temperature, as Devault and Chance observed. 

In a classical study the lipase-catalysed enantioselective hydrolysis of racemic p-nitrophenyl-2-methyldecanoate was chosen as the test reaction [15] (Fig. 8). The p-nitrophenyl ester was employed in the kinetic resolution instead of the methyl or ethyl ester, in order to make screening possible [76] (see below). The lipase from the bacterium Pseudomonas aeruginosa PAOl [77] was used as the enzyme [ 15]. The wild-type enzyme shows an enantioselectivity (ee) of only 2 % in favour of the (S)-configured 2-methyldecanoic acid, which means that the enzyme had essentially no preference for either of the enantiomeric forms. 

Fig. 11. EPR Spectra of wild-type and mutant (T4) Rp. v/rid/s chromatophores at 4.5 K generated by one flash at room temperature prior to freezing in the dark. Presence or absence of DCMU is indicated in the figure. See text for discussion. Figure source Sinning, Michel, Mathis and Rutherford (1989) Terbutryn resistance in a purple bacterium can induce sensitivity toward plant herbtoide DCMU. FEBS Lett 256 193.

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