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A new isolate, Gordonia sp. strain TY-5, is capable of growth on propane and n-alkanes with [C.sub.13] to [C.sub.22] carbon chains as the sole source of carbon. In whole-cell reactions, significant propane oxidation to 2-propanol was detected. A gene cluster designated prmABCD, which encodes the components of a putative dinuclear-iron-containing multicomponent monooxygenase, including the large and small subunits of the hydroxylase, an NADH-dependent acceptor oxidoreductase, and a coupling protein, was cloned and sequenced. A mutant with prmB disrupted (prmB::[Kan.sup.r]) lost the ability to grow on propane, and Northern blot analysis revealed that polycistronic transcription of the prm genes was induced during its growth on propane. These results indicate that the prmABCD gene products play an essential role in propane oxidation by the bacterium. Downstream of the prm genes, an open reading frame (adh1) encoding an NA[D.sup.+]-dependent secondary alcohol dehydrogenase was identified, and the protein was purified and characterized. The Northern blot analysis results and growth properties of a disrupted mutant (adh1::[Kan.sup.r]) indicate that Adh1 plays a major role in propane metabolism. Two additional NA[D.sup.+] -dependent secondary alcohol dehydrogenases (Adh2 and Adh3) were also found to be involved in 2-propanol oxidation. On the basis of these results, we conclude that Gordonia sp. strain TY-5 oxidizes propane by monooxygenase-mediated subterminal oxidation via 2-propanol.

Rhodococcus sp. strain MS11 was isolated from a mixed culture. It displays a diverse range of metabolic capabilities. During growth on 1,2,4-trichlorobenzene, 1,2,4,5-tetrachlorobenzene (1,2,4,5-TeCB) and 3-chlorobenzoate stoichiometric amounts of chloride were released. It also utilized all three isomeric dichlorobenzenes and 1,2,3-trichlorobenzene as the sole carbon and energy source. Furthermore, the bacterium grew well on a great number of n-alkanes ranging from n-heptane to n-triacontane and on the branched alkane 2,6,10,14-tetramethylpentadecane (pristane) and slowly on n-hexane and n-pentatriacontane. It was able to grow at temperatures from 5 to 30[degrees]C, with optimal growth at 20[degrees]C, and could tolerate 6% NaCl in mineral salts medium. Genes encoding the initial chlorobenzene dioxygenase were detected by using a primer pair that was designed against the [alpha]-subunit (TecA1) of the chlorobenzene dioxygenase of Ralstonia (formerly Burkholderia) sp. strain PS12. The amino acid sequence of the amplified part of the [alpha]-subunit of the chlorobenzene dioxygenase of Rhodococcus sp. strain MS11 showed > 99 % identity to the [alpha]-subunit of the chlorobenzene dioxygenase from Ralstonia sp. strain PS12 and the parts of both [alpha]-subunits responsible for substrate specificity were identical. The subsequent enzymes dihydrodiol dehydrogenase and chlorocatechol 1,2-dioxygenase were induced in cells grown on 1,2,4,5-TeCB. During cultivation on medium-chain-length n-alkanes ranging from n-decane to n-heptadecane, including 1-hexadecene, and on the branched alkane pristane, strain MS11 produced biosurfactants lowering the surface tension of the cultures from 72 to [less than or equal to]29 mN [m.sup.-1]. Glycolipids were extracted from the supernatant of a culture grown on n-hexadecane and characterized by [sup.1]H- and [sup.13]C-NMR-spectroscopy and mass spectrometry. The two major components consisted of [alpha],[alpha]-trehalose esterified at C-2 or C-4 with a succinic acid and at C-2' with a decanoic acid. They differed from one another in that one 2,3,4,2'-trehalosetetraester, found in higher concentration, was esterified at C-2, C-3 or C-4 with one octanoic and one decanoic acid and the other one, of lower concentration, with two octanoic acids. The results demonstrate that Rhodococcus sp. strain MS11 may be well suited for bioremediation of soils and sediments contaminated for a long time with di-, tri- and tetrachlorobenzenes as well as alkanes.

Expression of the genes of the alkane degradation pathway encoded in the Pseudomonas putida OCT plasmid are subject to negative and dominant global control depending on the carbon source used and on the physiological status of the cell. We investigated the signals responsible for this control in chemostat cultures under conditions of nutrient or oxygen limitation. Our results show that this global control is not related to the growth rate and responds to two different signals. One signal is the concentration of the carbon source that generates the repressing effect (true catabolite repression control). The second signal is influenced by the level of expression of the cytochome o ubiquinol oxidase, which in turn depends on factors such as oxygen availability or the carbon source used. Since under carbon limitation conditions the first signal is relieved but the second signal is not, we propose that modulation mediated by the cytochrome o ubiquinol oxidase is not classical catabolite repression control but rather a more general physiological control mechanism. The two signals have an additive, but independent, effect, inhibiting induction of the alkane degradation pathway.

Research has been conducted on the optically active amino alcohol preparation. The role of various fungi and yeasts in the 2-oxocycloalkanecarbonitrile stereoselective bioreduction has been investigated and the details are presented.

Research has been conducted on the 4,4'-(1,n-alkanediyl)bisbenzyl biradicals. The production of these compounds from the Norrish type-I reaction of [3,n]paracyclophan-2-ones in giving paracyclophans and the study of the biradicals' behavior are discussed.

Research has been conducted on the light alkanes and the alkyl side-chain of aromatic compounds. Nitration of these compounds with NO (sub)2 and HNO (sub)3 has been carried out under mild conditions via the use of N-hydroxyphthalimide catalyst and the details are reported.

Research has been conducted on the microbial enzymes, haloalkane dehalogenase. The cloning, sequencing and expression of the dhmA haloalkane dehalogenase gene from Mycobacterium avium subsp. avium N85 have been carried out and the results of DhmA biochemical characterization from crude extracts are reported.

Research has been conducted on the homoleptic aluminum thiolate complex. The preparation of this complex via the reaction of AlBr (sub)3 with NaS-t-Bu is described and the results indicate that the new compounds are thermally stable volatile liquids at moderate temperatures.

Research has been conducted on the molecular monolayers self-assembled on gold surfaces. The study of the mechanical properties, adhesion and friction of these monolayers carried out via the use of interfacial force microscopy is analyzed.

Research has been conducted on the gamma-irradiated CCl (sub)3 F/n-alkane solutions. The studies of these solutions carried out via the use of the electron paramagnetic resonance spectroscopy and gas chromatographic analysis after melting are discussed.

The authors review the publications on the radical and single-electron-transfer chemistry. The topics of interest include the mechanism of the alkane activation reaction, radical chemistry, traditional reagents and electrophilic radical-like species.

Research has been conducted on cyclodextrins, cyclic compounds consisting of glucose units. The study of the interactions of these compounds with such compounds as diaminobutane, diaminohexane and diaminooctane carried out in aqueous solutions via NMR diffusion measurements is described.

Research has been conducted on the hydrocarbon oxidation reaction mechanism. The use of the hybrid density functional method in studying the mechanism of this reaction is described.

Research has been conducted on Pseudomonas putida PAO1 alkane hydroxylases. The ability of the alkane hydroxylases to oxidize n-alkenes has been tested via the use of different recombination hosts and the results are reported.

Research has been conducted on rubredoxins. The sequence analysis and complementation studies indicate that these rubredoxins can be divided into AlkG1-type and AlkG2 rubredoxins and the mutagenesis results show which sequence elements determine whether rubredoxins can transfer electrons to alkane hydroxylase.

Research has been conducted on the wax ester production. The intracellular inclusion body ultrastructure and the metabolic pathway for the wax ester synthesis from n-alkanes have been investigated and the results are reported.

Research has been conducted on the chlorine atom/carbon disulfide complex. The structure and bonding of this complex which is involved in the photochlorination reactions have been carried out via the use of the transient resonance Raman spectroscopy and the results are reported.

Research has been conducted on the palladium-catalyzed-arylation of nitroalkenes.The general protocol for this arylation has been developed and the results indicate that the nitroalkene arylation can be effected over ketone and ester arylation.

Research has been conducted on the photochemical Wolff rearrangements in alkane solvents. The results of the the conventional UV and IR spectroscopic analysis indicate that these rearrangements have produced pentafulvenone, 2,3-benzopentafulvenone, dibenzopentafulvenone and 2,4-di-tert-butylpentafulvenone.

Research has been conducted on the OCT plasmid of Pseudomonas putida GPo1. The role of catabolite repression control in the catabolic repression of the alkane degradation pathway encoded in the OCT plasmid has been investigated and the results are reported.

An experiment shows students how the mass of certain molecules relates to the boiling point of liquids.

Research has been conducted on the alkanes and electron-deficient alkenes. The radical addition of alkanes and molecular oxygen to these electron-deficient alkenes has been carried out via the use of the N-hydroxyphthalimide in combination with the Co species as a catalyst and the results are reported.

Results demonstrate that diepoxybutane and diepoxyoctane target 5'-GNC sites for cross-linking in 5S DNA restriction fragments. However, the sites for both monoalkylation and interstrand cross-linking are similar in nucleosomal and free DNA. The cross-linked DNA is incorporated into the nuclosomal core particle structure.

Rhodococcus equi strains, deficient in biosurfactant formation, take up C(sub)16 alkanes by direct interfacial uptake during their growth on long-chain alkanes as revealed by the degradation kinetics of C(sub)16 alkanes.

Research has been conducted on the yeast Yarrowia lipolytica. The integrative vectors for gene expression in Y. lipolytica which carry long terminal repeat of the Y. lipolytica retrotransposon have been developed and described.

Results show that the alkane hydroxylase gene of Burkholderia cepacia RR10 exhibits catabolite repression in the presence of organic acids and sugars in complex media. Data indicate that transcription of the gene is induced by alkanes of 12 to 30 carbon chain length and by alkanols.

Research has been conducted on the polar and radical pathways in the trimethylstannylation of bridge-head-substituted halo polycyclic alkanes. The molecular factors affecting these pathways have been investigated and the results are discussed.

Research has been conducted on the gitonic and distonic alkanonium dications. The structure and stabilities of these dications have been investigated at the computational level and the results indicate that dimethylation is the favorable mode of dissociation.

Research describes the isolation and characterization of homologous genes from Acinetobacter sp. strains M-1 and ADP1. Results show that in the strain M-1, two genes encode alkane hydroxylases which are differentially induced depending on the n-alkane chain length.

Results demonstrate an unique anerobic oxidation of n-alkanes to form (1-methylpentylsuccinate) in a denitrifying bacterium growing on n-hexanes as the only organic substrate. Data reveal that n-hexane is activated by a radical reaction and added on to fumarate cosubstrate to give (1-methylpentylsuccinate).

Results show that axenic cultures of the two Mycobacterial species, fortuitum and ratisbonense, are capable of biodegrading squalane. Data further show that the degradation pathway involves beta-oxidation as indicated by acrylic acid inhibition of the squalane and squalene degradation.

Research embodies 16S rRNA sequence analyses of five gram-positive haloalkane-utilizing bacteria from geographically diverse regions. Results point out that regions of the haloalkane dehalogenase gene are clustered in a single catabolic gene cluster.

An alkane-degrading, sulfate-reducing bacterial strain has been isolated from a petroleum contaminated sediment and studied to find out about its alkane-metabolism mechanism. The strain, AK-01, can oxidize alkanes to carbon dioxide. Sulfate reduction also takes place. It appears that the alkanes are anaerobically oxidized to fatty acids. Exogenous carbon seems to be added initially to an alkane at the C-2 position in such a way that the original terminal carbon on the alkane becomes a methyl group on the fatty acid formed after that. The carbon-addition reaction seems not to be a direct carboxylation of inorganic bicarbonate.

The Rhodococcus sp. strain Q15 is a psychotrophic bacteria isolated from Lake Ontario in Canada. Characterization of the strain demonstrated its ability to degrade and mineralize n-alkanes and diesel fuel at low temperatures. In an effort to determine the strain's alkane catabolic pathway, biochemical and genetic analyses were then conducted. Polymerase chain reaction revealed that Q15 possesses an aliphatic aldehyde dehydrogenase gene. Although this gene could play a possible role in alkane degradation, additional research on the subject is still needed.

Research has been conducted on the aldehydes. The details of aldehyde refluxing with benzotriazole and benzylcarbamate in the presence of p-TsOH in producing benzyloxycarbonylamino-1-(1-benzotriazolyl)alkane are reported.

Research has been conducted on the ring-opening lactone halosilation. The halosilation of the lactones with different reagents, such as Et (sub)3 SiH/MeI(PdCl (sub)2) and Et (sub)3 SiH/AllylBr(PdCl (sub)2) has been explored.