Genome sequence and functional genomic analysis of the oil-degrading bacterium Oleispira antarctica

M.K. and P.N.G. designed the work; T.N.C. performed physiological studies; M.K., M.F., Y.A.-R., A.B., N.L.-C., M.E.G., O.R.K., T.Y.N., S.K., I.L., O.V.G., M.M.Y. R.R. and P.N.G. were associated with genome annotation; H.J.H. performed lipids and FAME analysis; M.F., M-l.F., S.J., S.C. and J.P.A performed chaperonin anti-proteome analysis; A.-x. S., O.K., O.E., P.A.P., P.S. and Y.K. were associated with structural proteomics; A.T. and R.F. were associated with functional proteomics; H.L. performed electron microscopy; R.D. performed real-time PCR; M.M.-G. and M.F. performed DIGE proteome analysis; M.G. was involved in siderophore production; O.N.R. performed genomic islands’ analysis; H.T. performed storage lipid compounds’ analysis; P.N.G. coordinated manuscript writing.Accession Codes: The genome sequence of Oleispira antarctica RB-8 has been deposited in GenBank under accession core FO203512. Protein structures have deposited in PDB under accession codes 3QVM (a/b hydrolase, OLEAN_C08020), 3QVQ (phosphodiesterase, OLEAN_C20330), 3M16 (transaldolase, OLEAN_C18160), 3LQY (isochorismatase, OLEAN_C07660), 3LNP (amidohydrolase, OLEAN_C13880), 3V77/3L53 (fumarylacetoacetate isomerase/hydrolase, OLEAN_C35840), 3VCR/3LAB (2-keto-3-deoxy-6-phosphogluconate aldolase, OLEAN_C25130), 3IRU (phoshonoacetaldehyde hydrolase, OLEAN_C33610), 3I4Q (inorganic pyrophosphatase, OLEAN_C30460), 3LMB (protein with unknown function, OLEAN_C10530).Ubiquitous bacteria from the genus Oleispira drive oil degradation in the largest environment on Earth, the cold and deep sea. Here we report the genome sequence of Oleispira antarctica and show that compared with Alcanivorax borkumensis—the paradigm of mesophilic hydrocarbonoclastic bacteria—O. antarctica has a larger genome that has witnessed massive gene-transfer events. We identify an array of alkane monooxygenases, osmoprotectants, siderophores and micronutrient-scavenging pathways. We also show that at low temperatures, the main protein-folding machine Cpn60 functions as a single heptameric barrel that uses larger proteins as substrates compared with the classical double-barrel structure observed at higher temperatures. With 11 protein crystal structures, we further report the largest set of structures from one psychrotolerant organism. The most common structural feature is an increased content of surface-exposed negatively charged residues compared to their mesophilic counterparts. Our findings are relevant in the context of microbial cold-adaptation mechanisms and the development of strategies for oil-spill mitigation in cold environments.We acknowledge the funding from the EU Framework Program 7 to support Projects MAMBA (226977), ULIXES (266473), MAGIC PAH (245226) and MICROB3 (287589) This work received the support of the Government of Canada through Genome Canada and the Ontario Genomics Institute (grant 2009-OGI-ABC-1405 to A.F.Y. and A.S.), and the U.S. Government National Institutes of Health (grants GM074942 and GM094585 (to A.S. through Midwest Center for Structural Genomics). The study was supported by the Max Planck Society and the Deutsche Forschungsgemeinschaft through project KU 2679/2-1 and BU 890/21-1. We thank the sequencing team of the AG Reinhardt for technical assistance and Alfred Beck for computational support. The skilful work of electron microscopic sample preparation by Mrs. Ingeborg Kristen (Dept. VAM, HZI Braunschweig) is gratefully acknowledged. Authors thank Professor Ken Timmis for his critical reading the manuscript and useful comments.http://www.nature.com/naturecommunicationsam201

Layer-by-Layer coated tyrosinase: An efficient and selective synthesis of catechols

Agaricus bisporous tyrosinase was immobilized on commercial available epoxy-resin Eupergit (R) C250L and then coated by the Layer-by-Layer method (LbL). The two novel heterogeneous biocatalysts were characterized for their morphology, pH and storage stability, kinetic properties (K-m, V-max, V-max/K-m) and reusability. These biocatalysts were used for the efficient and selective synthesis of bioactive catechols under mild and environmental friendly experimental conditions. Ascorbic acid was added in the reaction medium to inhibit the formation of ortho-quinones, thus avoiding the known enzyme suicide inactivation process. Catechols were obtained mostly in quantitative yields and conversion of substrate. Tyrosinase immobilized on Eupergit (R) C250L and coated by the LbL method showed better catalytic activities, higher pH and storage stability, and reusability with respect to immobilized uncoated tyrosinase. Since chemical procedures to synthesize catechols are often expensive and with high environmental impact, the use of immobilized tyrosinase represents an efficient alternative for the preparation of this family of bioactive compounds. (C) 2011 Elsevier Ltd. All rights reserved

Four years' follow-up results of three different percutaneous treatments for male varicocele

Objective: To evaluate the efficacy of three different interventional radiological procedures for the treatment of venous reflux in symptomatic male varicocele. Design: Prospective study with a 48-month colour duplex ultrasound (CD) follow-up. Setting: Department of Radiology, Tor Vergata University of Pome. Patients: From January 1991 to December 1993, 45 symptomatic patients with third- to fourth-degree varicocele, according to Sarteschi's CD classification, were randomly divided into three equal groups (15 patients each). Interventions: The first group received sclerotherapy (Athoxysclerol), the second underwent embolisation (Gianturco coils), while the third group received combined sclero-embolisation therapy (Athoxysclerol and Gianturco coils). Main outcomes measures: The frequency of recurrence for each procedure. Results: Two recurrences (13%) after 1 and 2 years occurred in patients who underwent sclerotherapy. In the embolisation group, two patients showed residual varices (13%). Neither recurrence nor-residue was seen in the third group, who received combined therapy. Conclusions: Sclerotherapy provides good immediate results but drug dilution may cause a relapse shortly after treatment. Embolisation has a lower immediate success but better long-term success. Combined treatment provides the highest long-term success-rate

Dye Degradation by Layer by Layer Immobilized Peroxidases/Redox Mediator Systems

Horseradish peroxidase (HRP) was immobilised on Eupergit C250L resin coated with poly-electrolytes, or by entrapment inside pre-formed layer-by-layer (LbL) micro-capsules of poly-electrolytes. In these systems, namely HRP/E-LbL, HRPm/LbL and HRPm/LbLp, the native enzyme retained its catalytic activity. Immobilised HRP showed a significant activity in the oxidation of selected azo, quinoline and fluorone dyes with H2O2 as the primary oxidant under mild experimental conditions, and HRPm/LbL was the best catalyst. A comparison between the catalytic efficiency of different redox mediators for HRP activity was made by using 1-hydroxybenzotriazole (HOBt), violuric acid (VLA) and veratrylic alcohol (VA). As a general trend, azo dyes were degraded in higher yields, and HOBt was the best mediator for the oxidation. The degradation yield increased on increasing the reaction time and reached the highest value after 12h, which is comparable with that observed for native HRP. Notably, HRPm/LbL retained its catalytic activity for more runs