Recent advances in molecular biology have extended our understanding of the metabolic processes related to microbial transformation of petroleum hydrocarbons. The physiological responses of microorganisms to the presence of hydrocarbons, including cell surface alterations and adaptive mechanisms for uptake and efflux of these substrates, have been characterized. New molecular techniques have enhanced our ability to investigate the dynamics of microbial communities in petroleum-impacted ecosystems. By establishing conditions which maximize rates and extents of microbial growth, hydrocarbon access, and transformation, highly accelerated and bioreactor-based petroleum waste degradation processes have been implemented. Biofilters capable of removing and biodegrading volatile petroleum contaminants in air streams with short substrate-microbe contact times ( 2 S and sulfoxides from petrochemical waste streams. Microbes also have potential for use in removal of nitrogen from crude oil leading to reduced nitric oxide emissions provided that technical problems similar to those experienced in biodesulfurization can be solved. Enzymes are being exploited to produce added-value products from petroleum substrates, and bacterial biosensors are being used to analyze petroleum-contaminated environments.

Recent Advances in Petroleum Microbiology

Metal–salen complexes as efficient catalysts for the oxygenation of heteroatom containing organic compounds—synthetic and mechanistic aspects

A screening for dye-decolorizing alkali-thermophilic microorganisms resulted in a Bacillus sp. strain isolated out of the wastewater drain of a textile finishing company. An NADH-dependent azoreductase of this strain, Bacillus sp. strain SF, was found to be responsible for the decolorization of azo dyes. This enzyme was purified by a combination of ammonium sulfate precipitation and anion-exchange and affinity chromatography and had a molecular mass of 61.6 kDa and an isoelectric point at pH 5.3. The pH optimum of the azoreductase depended on the substrate and was within the range of pHs 8 to 9, while the temperature maximum was reached at 80°C. Decolorization only took place in the absence of oxygen and was enhanced by FAD, which was not consumed during the reaction. A 26% similarity of this azoreductase to chaperonin Cpn60 from a Bacillus sp. was found by peptide mass mapping experiments. Substrate specificities of the azoreductase were studied by using synthesized model substrates based on di-sodium-(R)-benzyl-azo-2,7-dihydroxy-3,6-disulfonyl-naphthaline. Those dyes with NO2 substituents, especially in the ortho position, were degraded fastest, while analogues with a methyl substitution showed the lowest degradation rates.

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A New Alkali-Thermostable Azoreductase from Bacillus sp. Strain SF

Triboelectric nanogenerators (TENGs) have been invented as a new technology for harvesting mechanical energy, with enormous advantages. One of the major themes in their development is the improvement of the power output, which is fundamentally determined by the triboelectric charge density. Besides the demonstrated physical surface engineering methods to enhance this density, chemical surface functionalization to modify the surface potential could be a more effective and direct approach. In this paper, we introduced the method of using self-assembled monolayers (SAMs) to functionalize surfaces for the enhancement of TENGs' output. By using thiol molecules with different head groups to functionalize Au surfaces, the influence of head groups on both the surface potential and the triboelectric charge density was systematically studied, which reveals their direct correlation. With amine as the head group, the TENG's output power is enhanced by ∼4 times. By using silane-SAMs with an amine head group to modify the silica surface, this approach is also demonstrated for insulating triboelectric layers in TENGs. This research provides an important route for the future research on improving TENGs' output through materials optimization.

Molecular surface functionalization to enhance the power output of triboelectric nanogenerators

A coordination chemistry approach towards ternary M/14/16 anions

SULFUR BONDING. INTRODUCTION. PROPERTIES OF SULFUR BONDS. PARTICIPATION OF 3D ORBITALS IN SULFUR BONDING. BONDING IN TRI- AND TETRACOORDINATE SULFUR. WHY ARE "a-DISULFOXIDES" SO UNSTABLE? s-SULFURANE-HYPERVALENCY. HYPERVALENT INTERACTIONS. THE STEREOELECTRONIC EFFECTS OF SULFUR GROUPS. INTRODUCTION. DICOORDINATE SULFUR GROUPS. Electron-Releasing Conjugative Effects. Electron-Sharing Conjugative Effects. Electron-Accepting Conjugative Effects. TRICOORDINATE AND TETRACOORDINATE SULFUR GROUPS. NEIGHBORING GROUP EFFECTS OF SULFUR GROUPS. Dicoordinate Sulfur Groups. Sulfoxides. STEREOCHEMISTRY. INTRODUCTION. TRICOORDINATE SULFUR COMPOUNDS. Structure and Pyramidal Inversion. Sulfoxides. Sulfinate and Thiosulfinate Esters. Sulfonium and Alkoxysulfonium Salts. Sulfilimine and Related Derivatives. Other Tricoordinate Sulfur Compounds. TETRACOORDINATE SULFUR COMPOUNDS. PENTACOORDINATE AND POLYCOORDINATE SULFUR COMPOUNDS. STEREOCHEMISTRY OF a-SULFINYL CARBANIONS. STEREOCHEMISTRY OF a-SULFONYL CARBANIONS. SUBSTITUTION. INTRODUCTION. DICOORDINATE SULFUR COMPOUNDS. Nucleophilic Substitution. Free Radical Substitution. TRICOORDINATE SULFUR COMPOUNDS. Nucleophilic Substitution by SN1-Type Reactions. Nucleophilic Substitution by Ligand Exchange. NUCLEOPHILIC SUBSTITUTIONS ON TETRACOORDINATE SULFUR ATOM-POSSIBLE INVOLVEMENT OF HYPERVALENT INTERMEDIATES. Mode of Bond Fission and Electronic Effects. Effect of Ring Size. Neighboring Group Participation. Reactions at the a-Carbon. PENTACOORDINATE SULFUR COMPOUNDS. LIGAND COUPLING REACTIONS WITHIN HYPERVALENT SPECIES. CONCEPT OF LIGAND COUPLING WITHIN s-SULFURANE INTERMEDIATES. STEREOCHEMISTRY OF LIGAND COUPLING ON SULFUR. LIGAND COUPLING AND LIGAND EXCHANGE ON SULFUR. LIGAND COUPLING AND PSEUDOROTATION. OTHER EXAMPLES. LIGAND COUPLING ON OTHER ATOMS. OXIDATION OF SULFOXIDES WITH METAL OXIDES. REDUCTION OF SULFILIMINES WITH METAL HYDRIDES. OXIDATION AND OXYGENATION. INTRODUCTION. OXIDATION OF THIOLS TO DISULFIDES. Air Oxidation. Metal Oxides and Metallic Ions. Sulfoxides, Amine N-Oxides and Peroxides. Halogens and Halogenating Agents. Nitrogen Compounds. Flavin Derivatives. Photo-Oxidation. OXIDATION OF THIOLS AND DISULFIDES TO SULFUR SPECIES OF HIGHER OXIDATION STATES. Nucleophilic Oxidation. Electrophilic Oxidation. Oxygenation with Enzymes. OXIDATION AND OXYGENATION OF SULFIDES AND SULFOXIDES. Electrophilic Oxidation. Nucelophilic Oxidation. One-Electron Transfer Oxygenation-A Comparison of Cytochrome P-450 and FAD-Containing Monooxygenase. Stereochemistry. REDUCTION. INTRODUCTION. REDUCTION OF DISULFIDES TO THIOLS. Metal Hydrides. Electron Transfer and Photolysis. Thiols and Selenols. Formamidinesulfinic Acid. Tricoordinate Phosphorus Compounds. REDUCTION OF SULFENIC ACID AND SULFENIC ACID DERIVATIVES. Thiols. Electrode Reduction. Silicon and Tin Hydrides. REDUCTION OF SULFINIC ACID AND SULFINIC ACID DERIVATIVES. Phosphorus Compounds. Hydrogen Halides and Trimethylsilyl Iodide. Lithium Aluminum Hydride. Hydrazine. Trichlorosilane. Sodium Metal. Thiols. Grignard Reagents. REDUCTION OF THIOLSULFINATES. Thiols. Phosphines. Cyanide. REDUCTION OF SULFOXIDE, SULFILIMINE AND SULFONIUM YLIDES. Metal Hydrides. Carbenes. Metal and Metal Complexes. Tricoordinate Phosphorus Compounds. Iodide Ion. Sulfur Compounds. Other Procedures. REDUCTION OF SULFONES AND SULFOXIMINES. Elemental Sulfur. Metal Hydrides. Zinc and Hydrochloric Acid and Samarium Iodide. Aryldiazonium Salts. Metals-Reductive Cleavage. Electrochemical Reduction. Nitrosation of Sulfoximines. Carbenes. REDUCTION OF SULFONYL DERIVATIVES. Sodium Sulfite. Halide Ions. Lithium Aluminum Hydride. Metals and Metal Salts. One-Electron Transfer Reactions. Electrochemical Reduction. Free Radical Reductions. Tricoordinate Phosphorus Compounds. Thiols. Other Procedures. REDUCTION OF SULFONIC ACIDS. Nickel-Aluminum. Electrochemical and One-Electron Transfer Reductions. Iodide/Trifluoroacetic Anhydride. Triphenyl Phosphine with Iodine or Disulfides. Borane Derivatives. Polyphosphoric Acid Derivatives with Iodide. Phosphorus Pentasulfide. REDUCTION OF SULFURIC ACID AND SULFATE. REARRANGEMENTS. INTRODUCTION. THE STEVENS REARRANGEMENT. THE SOMMELET-HAUSER OR THE MOFFATT-PFITZNER REARRANGEMENT. THE PUMMERER REARRANGEMENT. SIGMATROPIC REARRANGEMENTS. [1,j]-Sigmatropic Reactions. [3,3]-Sigmatropic Reactions. [2,3]-Sigmatropic Reactions. OTHER REARRANGEMENTS.

Shigeru Oae

Papers

Organic Sulfur Chemistry: Structure and Mechanism