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The genome of Pseudomonas putida KT2440 encodes five proteins of the phosphoenolpyruvate-earbohydrate phosphotransferase system. Two of these (FruA and FruB) form a dedicated system for fructose intake, while enzyme [I.sup.Ntr] (E[I.sup.Ntr]; encoded by ptsP), NPr (ptsO), and EI[I.sup.Ntr] (ptsN) act in concert to control the intracellular accumulation of polyhydroxyalkanoates, a typical product of carbon overflow.

Cr(VI) chromate is a known environmental contaminant because of the widespread use of chromium compounds by tanning, corrosion control or plating industries but bacteria can reduce chromate to the insoluble and less toxic Cr(III), thus making chromate bioremediation a matter of great interest. Studies were conducted on chromate reductase activities of two electophoretically soluble bacterial flavoproteins.

Chemotaxis to the aromatic acid 4-hydroxybenzoate (4-HBA) by Pseudomonas putida is mediated by PcaK, a membrane-bound protein that also acts as a 4-HBA transporter. To determine if PcaK has functional requirements similar to those of other major facilitator superfamily transport proteins and to study the relationship between the transport and chemotaxis functions of PcaK, strains with mutations in amino acid residues in the 2-3 and 8-9 loops of PcaK were generated. Findings showed that conserved amino acids in the 2-3 and 8-9 loops of PcaK are needed for 4-HBA transport.

A study was conducted to show that the expression of the Gef protein or the X174 E protein in Pseudomonas putida brings about cell death resulting from the formation of membrane holes. Killing efficiency was evaluated with a liquid medium while P. putida cells were determined by centrifugation. Results indicated that the expression of the proteins in P. putida cells made the cell envelope of the heterologous host lose its integrity. It also facilitated the release of cytoplasmic content to the extracellular medium.

A study is conducted to determine the effectiveness of the XylR protein in controlling expression from the TOL plasmid upper pathway operon promoter of Pseudomonas putida. Results indicate the dose dependence of the activation of transcription from Pu using the protein. These results to varying induction kinetics with different effectors. The productive or unproductive transcriptional state of XylR is dependent upon the nature of the substituent on the aromatic ring of the effector.

Two-dimensional polyacrylamide electrophoretic analysis of the responses of Pseudomonas putida KT2442 to nutrient starvation shows that carbon deprivation causes the production of starvation- and stress-induced proteins. The recovery phase begins when glucose is added to this carbon-starved culture and is characterized by the introduction of a new type of transiently expressed proteins and the suppression of starvation-induced proteins.

Combinatorial methods are adopted to control reporter gene expression at the transcriptional level in Methylobacterium extorquens in order bestow inducibility upon the cloned [P.sub.maxF] promoter in expression vectors. It is the first documented example of an inducible and tightly regulated expression of heterologous genes in Methylobacterium extorquens.

Nuclear magnetic resonance spectroscopy was used to describe the three-dimensional structure of the pyoverdin G4R-Ga(III) complex from Pseudomonas putida and the features of the structure responsible for iron complexation and receptor binding. The complex was found to be tightly defined with a compact structure. The site of the complexation of the iron ion was located on the surface of the molecule, showing that the ion can be released without large conformational changes.

A novel reporter system was constructed for the monitoring of cellular growth activity. By constructing an expression cassette consisting of the novel green fluorescent protein gene expressed from an Escherichia coli rRNA promoter, the reporter system was derived, generating green fluorescence in fast-growing cells of both E coli and Pseudomonas putida. Results indicate that the dynamics of biofilm growth activity can be traced to the level of individual cells, cell clusters and microcolonies.

A study has been conducted to investigate the 15N backbone dynamics of putidaredoxin (Pdx) as a function of its oxidation state, where the motions studied are in the picoseconds to nanoseconds time scale. Among these motions include the concerted motions of several atoms, rotation of surface side chains and torsional vibrations. The order parameters of the reduced Pdx and oxidized Pdx were calculated to determine the entropy change within the oxidation of reduced Pdx.