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11.
Gates RR 《Science (New York, N.Y.)》1910,31(794):425-426
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Béjà O Aravind L Koonin EV Suzuki MT Hadd A Nguyen LP Jovanovich SB Gates CM Feldman RA Spudich JL Spudich EN DeLong EF 《Science (New York, N.Y.)》2000,289(5486):1902-1906
Extremely halophilic archaea contain retinal-binding integral membrane proteins called bacteriorhodopsins that function as light-driven proton pumps. So far, bacteriorhodopsins capable of generating a chemiosmotic membrane potential in response to light have been demonstrated only in halophilic archaea. We describe here a type of rhodopsin derived from bacteria that was discovered through genomic analyses of naturally occuring marine bacterioplankton. The bacterial rhodopsin was encoded in the genome of an uncultivated gamma-proteobacterium and shared highest amino acid sequence similarity with archaeal rhodopsins. The protein was functionally expressed in Escherichia coli and bound retinal to form an active, light-driven proton pump. The new rhodopsin exhibited a photochemical reaction cycle with intermediates and kinetics characteristic of archaeal proton-pumping rhodopsins. Our results demonstrate that archaeal-like rhodopsins are broadly distributed among different taxa, including members of the domain Bacteria. Our data also indicate that a previously unsuspected mode of bacterially mediated light-driven energy generation may commonly occur in oceanic surface waters worldwide. 相似文献
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W Fiddler J W Pensabene R A Gates J M Foster W J Smith 《Journal of the Association of Official Analytical Chemists》1989,72(1):19-22
Dry-cured or "country-style" bacon is a low volume specialty product typically made by small producers whose production practices vary widely. These practices include the direct application of dry-cure formulations containing varying concentrations of salt, sugar, flavoring agents, sodium nitrite, and sometimes sodium nitrate, and the use of lengthy curing and processing times. Because of the possibility of generating higher levels of N-nitrosopyrrolidine (NPYR) after frying in this product type compared with pump-cured bacon, an investigation was carried out on dry-cured bacon obtained from cooperating state or federally inspected establishments. Three different samples from each of the 16 plants were analyzed. Only one sample from each of 2 different producers exceeded the Food Safety and Inspection Service (FSIS) action level of 17 ppb NPYR, indicating that the majority of samples tested were in compliance. A significant correlation (P less than 0.01) was found between residual NaNO2 prior to frying and NPYR after frying. The elimination of added nitrate in the dry-cure formulations is recommended. 相似文献
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Singh N Megharaj M Gates WP Churchman GJ Anderson J Kookana RS Naidu R Chen Z Slade PG Sethunathan N 《Journal of agricultural and food chemistry》2003,51(9):2653-2658
Hydrolysis of an insecticide/nematicide, fenamiphos [ethyl-3-methyl-4-(methylthio)phenyl-(1-methylethyl)phosphoramidate], immobilized through sorption by cetyltrimethylammonium-exchanged montmorillonite (CTMA-clay) by a soil bacterium, Brevibacterium sp., was examined. X-ray diffraction analysis, infrared spectra, and a negative electrophoretic mobility strongly indicated that fenamiphos was intercalated within the bacterially inaccessible interlayer spaces of CTMA-clay. The bacterium hydrolyzed, within 24 h, 82% of the fenamiphos sorbed by the CTMA-clay complex. There was a concomitant accumulation of hydrolysis product, fenamiphos phenol, in nearly stoichiometric amounts. During the same period, in abiotic (uninoculated) controls, 4.6% of the sorbed insecticide was released into the aqueous phase as compared to 6.0% of the sorbed fenamiphos in another abiotic control where activated carbon, a sink for desorbed fenamiphos, was present. Thus, within 24 h, the bacterium hydrolyzed 77% more fenamiphos sorbed by organo clay than the amounts desorbed in abiotic controls. Such rapid degradation of an intercalated pesticide by a bacterium has not been reported before. Evidence indicated that extracellular enzymes produced by the bacterium rapidly hydrolyzed the nondesorbable fenamiphos, even when the enzyme itself was sorbed. Fenamiphos strongly sorbed to an organo clay appears to be readily available for exceptionally rapid degradation by the bacterium. 相似文献
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D E Reed H Shave M E Bergeland C E Gates 《Journal of the American Veterinary Medical Association》1976,169(9):975-979
In a diagnostic survey of diseases in wild white-tailed deer (62 cases) and mule deer (12 cases) the most common findings were traumatic injury (20%), nontraumatic hemorrhage (13%), polioencephalomalacia (11%), and bacterial infections (9%). Although epizootic hemorrhagic disease was suspected in several cases, the virus was isolated from only 1 white-tailed deer. 相似文献
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P. J. Brooker P. S. Gates J. Gillon G. T. Newbold D. T. Saggers 《Pest management science》1972,3(6):735-744
A series of benzodioxolyl carbamates has been prepared and evaluated in the laboratory for insecticidal activity against a range of ten species. The results indicated that this was optimal with the 4-benzodioxolyl carbamates with a 2,2-dialkyl substitution. The most promising of these on the basis of cost-effectiveness was 2,2-dimethyl-1,3-benzodioxol-4-yl methylcarbamate, bendiocarb, which is being developed commercially for the control of household pests. 相似文献