The review examines literature relevant to environmental fate, transformation, and toxicity, and human exposure and health risks of neonicotinoid insecticides.

Genes for the subunits of particulate methane monooxygenase, PmoABC, have been sequenced from the y-proteobacterial methanotroph Methylococcus capsulatus Bath. M. capsulatus Bath contains two complete copies of pmoCAB, as well as a third copy of pmoC. The two pmoCAB regions were almost identical a t the nucleotide sequence level, differing in only 13 positions in 3183 bp. A t the amino acid level, each translated gene product contained only one differing residue in each copy. However, the pmOC3 sequence was more divergent from the two other pmoC copies a t both the far N-terminus and far C-terminus. Chromosomal insertion mutations were generated in all seven genes. Null mutants could not be obtained for pmOC3, suggesting that it may play an essential role in growth on methane. Null mutants were obtained for pmoCl, pmoC2, pmoAl, pmoA2, pmoBl and pmoB2. All of these mutants grew on methane, demonstrating that both gene copies were functional. Copy 1 mutants showed about two-thirds of the wild-type whole-cell methane oxidation rate, while copy 2 mutants showed only about one-third of the wildtype rate, indicating that both gene copies were necessary for wild-type particulate methane monooxygenase activity. It was not possible to obtain double null mutants that were defective in both pmo copies, which may indicate that some expression of pMMO is important for growth.

A green method for alkene epoxidation based on the chemo-enzymatic perhydrolysis of carboxylic acids and esters has been optimized using Novozyme 435, the immobilized form of Candida antarctica lipase B, and the complex urea-hydrogen peroxide (UHP). UHP, an anhydrous form of hydrogen peroxide, has the potential of releasing hydrogen peroxide in a controlled manner and thus avoids the need to add the aqueous hydrogen peroxide slowly to the reaction mixture. The absence of water in the reaction media was also beneficial, because it minimized undesired reactions of the oxidized products. A minimum amount of enzyme was necessary to show the catalytic effect. On recycling, the enzyme maintained its activity up to six rounds of epoxidations. A range of alkenes was epoxidized by this method providing yields ranging from 75 to 100 percent.

The extremely stable biomolecules manufactured by organisms from extreme environments are of great scientific and engineering interest in the development of robust and stable industrial biocatalysts. Identification of molecules that impart stability under extremes will also have a profound impact on our understanding of cellular survival. This review discusses isolation and characterization of archaeal tetraethers as well as target technologies for tetraether lipid application. The isolation and characterization of archaeal tetraether lipids has led to some interesting applications improving on ester lipid technologies. Potential applications include novel lubricants, gene-delivery systems, monolayer lipid matrices for sensor devices, and protein stabilization. Following this review, patent abstracts and additional literature pertaining to the isolation, characterization, and application of archaeal membrane lipids are listed.