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The cellular levels of the alternative sigma factor [[sigma].sup.54] of Pseudomonas putida have been examined in a variety of growth stages and culture conditions with a single-chain Fv antibody tailored for detection of scarce proteins. The levels of [[sigma].sup.54] were also monitored in P. putida strains with knockout mutations in ptsO or ptsN, known to be required for the C-source control of the [[sigma].sup.54]-dependent Pu promoter of the TOL plasmid. Our results show that ~80 [+ or -] 26 molecules of [[sigma].sup.54] exist per cell. Unlike that in relatives of Pseudomonas (e.g., Caulobacter), where fluctuations of [[sigma].sup.54] determine adaptation and differentiation when cells face starvation, [[sigma].sup.54] in P. putida remains unexpectedly constant at different growth stages, in nitrogen starvation and C-source repression conditions, and in the ptsO and ptsN mutant strains analyzed. The number of [[sigma].sup.54] molecules per cell in P. putida is barely above the predicted number of [[sigma].sup.54]-dependent promoters. These figures impose a framework on the mechanism by which Pu (and other [[sigma].sup.54]-dependent systems) may become amenable to physiological control.

Research has been conducted on DEH transposon from Pseudomonas putida strain PP3. The function, the structure of this transposon and the full sequence of DEH element, including ISPpu12, have been investigated, and the results from the experiments studying its transposition and associated effects are presented.

Research has been conducted on Pseudomonas putida mt-2 archetypal tolyene-xylene catabolic plasmid pWW0. The identification of the insertion sequence ISPpu12 on this plasmid has been carried out, and the details are reported.

Research has been conducted on the physiological changes of the plant saprophyte Pseudomonas putida. The effect of the 6 h of attachment to a silicon surface on the physiological changes of R. putida has been investigated via the protein profile analysis and mRNA expression patterns and the results are reported.

Research has been conducted on the recombinant phage antibody Phab. The strategy for the selection of this antibody which recognizes both XylR and other members of XylR class of regulators has been developed and the results demonstrate that this strategy helped to visualize the fluctuations in the intracellular XylR levels of Pseudomonas putida.

Research has been conducted on the Pseudomonas putida transposon Tn4652. Results indicate that the Tn4652 transposase promoter's transcription is controlled by the stationary-phase-specific sigma factor sigma (super)S.

Research has been conducted on arylketone monooxygenase purified from Pseudomonas putida JD1 by ion exchange and affinity chromatography. Results indicate that this monooxygenase has characteristics of the Baeyer-Villiger-type monooxygenase.

Research has been conducted on mandelate metabolic pathway enzymes which allow Pseudomonas putida ATCC 12633 to utilize mandalate enantiomers as a carbon source. The authors report the isolation and expression of open reading frame genes coding for mandalate dehydrogenase, mandalate racemase and benzylformate decarboxylase in Escherichia coli, and reveal that the purified gene products have been characterized as mandelamide hydrolase and NAD(P) (super)+ -dependent benzaldehyde dehydrogenase.

Research has been conducted on bacterial nitrous oxide reductase generating dinitrogen from N (sub)2 O. The study of the indispensable proteins carried out via expressing nos genes from Pseudomonas stutzeri in the nondenitrifying organism Pseudomonas putida is described.