Seven rabbit antisera were obtained by immunization with either N-(l-naphthylacetyl)-6-aminohexanoic acid (3) or l-(l-naphthyl)-3-(5-carboxypentyl)urea (8) conjugated to keyhole limpet hemocyanin (KLH). From these sera Ab2114 (against 8KLH) was used for the optimization of an enzyme-linked immunosorbent assay (ELISA) for the determination of the insecticide carbaryl. An I50 of 2-5 ng/mL and a detection limit of 0.2 ng/mL were obtained using N-(2-naphthoyl)8-aminohexanoic acid (5) coupled to conalbumin as a coating antigen. No interference with naphthol, the main degradation product of carbaryl, was observed. An enzyme tracer was prepared by covalently linking hapten 5 with alkaline phosphatase. When the ELISA was performed using a format involving coating the plate with antibodies, an 150 of 0.4-0.6 ng/mL and a detection limit of 0.05 ng/mL were obtained. Preliminary studies with different samples showed that this immunoassay can be used for the determination of carbaryl in water, soil, body fluids, and food samples. This paper demonstrates the flexibility of using stable derivatives of a target compound such as carbaryl to generate antibodies and a sensitive ELISA for molecules containing functionalities susceptible to chemical hydrolysis and biodegradation.

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The stabilities and electronic properties of SrZrO3 (1 1 0) (1  ×  1) polar terminations were investigated systematically by the first-principles density functional theory method. Five possible polar surfaces, i.e. O-deficient, O-rich, stoichiometric, SrO-rich and SrO-deficient ones, were considered. The calculated results indicated that the charge neutralization and polarity compensation condition could be achieved by charge redistributions of surface atoms. For the O-deficient (1 1 0) termination, some filled electronic states were separated from the original conduction bands, while a surface reconstruction was found for the O-rich (1 1 0) surface. The remaining three (1 1 0) terminations remained insulated. Furthermore, a stability diagram involving seven different terminations was constructed using the surface grand potential technique, in which the effect of the chemical environment was included. The calculated results indicated that three (1 1 0) (O-rich, SrO-rich and stoichiometric) and 2 (0 0 1) (ZrO2 and SrO) terminations could be stabilized in distinct areas, whereas the O-deficient surface was unstable within the whole region. Finally, we drew a comparison of stability behaviors between SrZrO3 (1 1 0) (1  ×  1) polar surfaces and the counterparts of ATiO3 (A = Ba, Pb, Sr) and BaZrO3 materials.

Ketogulonicigenium vulgare is characterized by the efficient production of 2KGA from L-sorbose. Ketogulonicigenium vulgare Y25 is known as a 2-keto-L-gulonic acid-producing strain in the vitamin C industry. Here we report the finished, annotated genome sequence of Ketogulonicigenium vulgare Y25.Ketogulonicigenium vulgare Y25 is used in the production of vitamin C, which is responsible for the conversion reaction of L-sorbose to L-ketogulonic acid in mixed culture fermentation with Bacillus species 8. The entire genome of Ketogulonicigenium vulgare Y25 was sequenced to elucidate the metabolic pathway of sorbose and to obtained detailed insights into the growth potential of the organism.The complete genome sequence of Ketogulonicigenium vulgare Y25 was determined by the Beijing Genome Institute (Shenjun, China) using Solexa technology. A total of 221 million high-quality base pairs, giving 67.2-fold coverage of the genome, were assembled into 36 contigs using by SOAP software (http://soap.genomics.org.cn) 7. Then, the contigs were joined into 14 scaffolds using paired-end information. Gaps between contigs were closed by custom primer walks or by PCR amplification followed by DNA sequencing.The genome of Ketogulonicigenium vulgare Y25 consists of a circular chromosome and two plasmids. The chromosome is composed of 2,776,084 bp, with a GϩC content of 61.72%. One plasmid contains 268,675 bp, with a GϩC content of 61.35%, and the other contains 243,645 bp, with a GϩC content of 62.63%. Hence, the total size of the genome is 3,288,404 bp and the average GϩC content is 61.76%. There are a total of 3,290 putative open reading frames (2,807 [chromosome], 256 [pYP1], and 227 [pYP2]) using Glimmer, giving a coding intensity of 91.05%. A total of 59 tRNA genes for all 20 amino acids but tyrosine and five 16S-23S-5S rRNA operons were identified.Four genes encoding sorbose dehydrogenase were found in the chromosome. All of them were cloned and characterized. The result indicated that every one could transform L-sorbose into 2-keto-gulonic acid and required pyrroloquinoline quinine for the prosthetic groups in vitro (unpublished data). Sequence alignment analysis showed that they hadhigh homology in nucleic acid and amino acid sequences 1, 4, 9, and 10. It is estimated that multiple copies of the sorbose dehydrogenase gene can be attributed to highly efficient conversion of sorbose to 2-keto-gulonic acid. A pqqABCDE cluster of coenzyme PQQ biosynthesis has also been isolated. It shows the same arrangement of pqq genes as that in other species: a small pqqA gene with its own promoter followed by an operon with the other four genes2, 3, 5, 6. In addition, several genes encoding sorbitol dehydrogenase, sorbose reductase, sorbsone dehydrogenase, etc., were annotated in the genome.The Y25 genome sequence and its curated annotation are important assets to better understand the physiology and metabolic potential of Ketogulonicigenium vulgare and will open up new opportunities in the functional genomics of this species.Nucleotide sequ...

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