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751.
Renato Capasso Antonio Evidente Ermenegildo Tremblay Andrea Sala Carmine Santoro Gennaro Cristinzio Francesco Scognamiglio 《Journal of chemical ecology》1994,20(5):1189-1199
Among the main polyphenols occurring in olive oil vegetation waters (VW), catechol showed the most deterrent action on the oviposition ofBactrocera oleae (Gmelin); 4-methylcatechol was less active, whereas hydroxytyrosol and tyrosol were inactive. In contrast, synthetico-quinone was found to be stimulant at 7.5 × 10–2 M. Two other synthetic derivatives of catechol, diacetylcatechol and guaiacol, were also deterrent, suggesting these compounds undergo a biochemical transformation into catechol by means of the bacterial symbionts ofB. oleae. VW and their phenolic extracts showed deterrence only when highly concentrated, while natural olive juice was strongly deterrent. Experiments carried out to evaluate the effect of olive juice and catechol on the fecundity ofB. oleae showed that they strongly reduce this function. Moreover, the possible utilization of VW and their bioactive polyphenols in protection of olives againstBatrocera oleae is discussed. 相似文献
752.
S. S. Kanwar S. Pathak H. K. Verma S. Kumar R. Gupta S. S. Chimni G. S. Chauhan 《应用聚合物科学杂志》2006,100(6):4636-4644
Four series of noble networks were synthesized with acrylic acid (AAc) copolymerized with varying amount of 2‐hydroxy propyl methacrylate or dodecyl methacrylate (AAc/HPMA or AAc/DMA; 5:1 to 5:5, w/w) in the presence of ethylene glycol dimethacrylate (EGDMA; 1, 5, 10, 15, and 20%, w/w) as a crosslinker and ammonium per sulfate (APS) as an initiator. Each of the networks was used to immobilize a purified lipase from Pseudomonas aeruginosa MTCC‐4713. The lipase was purified by successive salting out with (NH4)2SO4, dialysis, and DEAE anion exchange chromatography. Two of the matrices, E15a, i.e. [poly (AAc5‐co‐DMA1‐cl‐EGDMA15)] and I15c, i.e. [poly (AAc5‐co‐HPMA3‐cl‐EGDMA15)], that showed relatively higher binding efficiency for lipase were selected for further studies. I15c‐hydrogel retained 58.3% of its initial activity after 10th cycle of repetitive hydrolysis of p‐NPP, and I15c was thus catalytically more stable and efficient than the other matrix. The I15c‐hydrogel‐immobilized enzyme showed maximum activity at 65°C and pH 9.5. The hydrolytic activity of free and I15c‐hydrogel‐immobilized enzyme increased profoundly in the presence of 5 mM chloride salts of Hg2+, NH4+, Al3+, K+, and Fe3+. The immobilized lipase was preferentially active on medium chain length p‐nitrophenyl acyl ester (C:8, p‐nitrophenyl caprylate). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4636–4644, 2006 相似文献
753.
O. Mi Lee Jong Hyeok Oh Marie Libert Doo Seong Hwang Yun Dong Choi Jin Ho Park Un Soo Chung Byung Real Jo Min Ju Kim Sang-Joon Lee 《Korean Journal of Chemical Engineering》2008,25(4):787-792
The treatment of lagoon sludge is a serious task during the decommissioning of a uranium conversion plant. The main component
of the sludge is ammonium nitrate, which is a very explosive material. Therefore, biological removal of the ammonium nitrate
would be an attractive process. In this work, the bio-denitrification of the nitrate solution from lagoon sludge with a continuous
fermentation process was studied. The optimal conditions for removal of nitrate by Pseudomonas halodenitrificans in the continuous bio-reduction process were a C/N ratio and pH of 3.1 and 7.5, respectively, with CO2 gas control, and five times the microelements as used in a batch culture, at 30 °C. It was concluded that bio-denitrification
could be applicable to lagoon sludge waste, but with some limitations. 相似文献
754.
Pinaki Sar Stanislaus F D'Souza 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2001,76(12):1286-1294
The biosorptive uranium(VI) uptake capacity of live and lyophilized Pseudomonas cells was characterized in terms of equilibrium metal loading, effect of solution pH and possible interference by selected co‐ions. Uranium binding by the test biomass was rapid, achieving >90% sorption efficiency within 10 min of contact and the equilibrium was attained after 1 h. pH‐dependent uranium sorption was observed for both biomass types with the maximum being at pH 5.0. Metal uptake by live cells was not affected by culture age and the presence of an energy source or metabolic inhibitor. Sorption isotherm studies at a solution pH of either 3.5 or 5.0 indicated efficient and exceptionally high uranium loading by the test biomass, particularly at the higher pH level. At equilibrium, the lyophilized Pseudomonas exhibited a metal loading of 541 ± 34.21 mg g?1 compared with a lower value by the live organisms (410 ± 25.93 mg g?1). Experimental sorption data showing conformity to both Freundlich and Langmuir isotherm models indicate monolayered uranium binding by the test biomass. In bimetallic combinations a significant interference in uranium loading was offered by cations such as thorium(IV), iron(II and III), aluminium(III) and copper(II), while the anions tested, except carbonate, were ineffective. Uranium sorption studies in the presence of a range of Fe3+ and SO42? concentrations indicate a strong inhibition (80%) by the former at an equimolar ratio while more than 70% adsorption efficiency was retained even at a high sulfate level (30 000 mg dm?3). Overall data indicate the suitability of the Pseudomonas sp biomass in developing a biosorbent for uranium removal from aqueous waste streams. © 2001 Society of Chemical Industry 相似文献
755.
Shan Guobin Xing Jianmin Zhang Huaiying Liu Huizhou 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2005,80(4):420-424
Biodesulfurization is a promising technology for deep desulfurization. The remaining alkylated DBTs (dibenzothiophenes) in the HDS‐treated (hydrodesulfurized‐treated) diesel oil could be selectively and efficiently desulfurized by resting cells of Pseudomonas delafieldii R‐8, a Gram‐negative bacterium. The desulfurization activities of resting cells were greatly affected by W/O ratio (the volume ratio of aqueous phase to oil phase) and cell concentration. The desulfurization activity increased with the increase in the W/O ratio. When the W/O ratio and cell concentration were 2 and 25 mg cm?3, the desulfurization activity was as high as 0.41 mg(total sulfur) g?1(dry cell weight, DCW) h?1, ie higher than that reported previously. GC‐AED (gas chromatography with an atomic emission detector) analysis showed that the total reductions for all the C1DBTs and C2DBTs were approximately 100%, 94.63% for C3DBT, and 97.09% for C4DBT (designated CxDBT, where x is the number of alkyl groups attached). The rates of biodesulfurization relate to the number and position of alkyl groups attached to the DBT. Copyright © 2005 Society of Chemical Industry 相似文献
756.
Odafe F. P. Sideso Allison C. Marvier Nikolaos A. Katerelos & Peter W. Goodenough 《International Journal of Food Science & Technology》2001,36(6):693-698
Cell-free extracts (CFE) from Pseudomonas putida , cultured on caffeine as sole carbon and/or nitrogen source, contained proteins which demethylate caffeine. Caffeine metabolism correlated with production of two major proteins (43.5 and 36.6 kDa); we suggest that one or both of these are caffeine demethylase enzymes. HPLC analysis of caffeine degradation by P. putida showed that caffeine is converted to uric acid via 3–7-dimethylxanthine, 7-methylxanthine and xanthine. The stability of caffeine demethylase was greatly improved by the use of cryoprotectants and freeze drying to low moisture contents. Freeze-dried cell-free extracts maintained 83% of activity after 200 days of storage at 4 °C. 相似文献
757.
An extracellular lipase purified from Pseudomonas fluorescens MTCC 2421 was used to enrich sardine oil triglycerides with eicosapentaenoic acid (20:5 n−3) and linolenic acid (18:3 n−3) to 35.28% and 8.25%, respectively, after 6 h of hydrolysis. The corresponding n−6 fatty acids (18:2 n−6 and 20:4 n−6) exhibit a reduction (54.93% and 50%, respectively). Structure–bioactivity relationship analyses revealed that the lower hydrophobic (log P values) constants of 18:3 n−3 and 20:5 n−3 (5.65 and 5.85, respectively) result in their higher hydrolytic resistance towards lipase, leading to their enrichment in the triglyceride fraction after lipase-catalysed hydrolysis. Lipase-catalysed hydrolysis of sardine oil for 6 h followed by urea fractionation at 4 °C with methanol provided free fatty acids containing 42.50% 20:5 n−3 and 10.31% 18:3 n−3, respectively. Argentation neutral alumina column chromatography, using n-hexane/ethylacetate (2:1, v/v) resulted in 20:5 n−3 of high purity (83.62%), while 18:3 n−3 was found to be eluted with n-hexane/dichloromethane (4:1, v/v) as eluting solvent with a final purity of 75.31%. 相似文献
758.
Based on the properties of ozone as a strong germicidal agent, inactivation kinetics of Pseudomonas aeruginosa, Escherichia coli, Shigella sonnei and Salmonella typhimurium towards ozone in water were studied. The values of 90% inactivation (t90) obtained varied from 0.20 minutes (2.4 mg/L, Escherichia coli ATCC 25922) to 8.33 minutes (0.39 mg/L, Pseudomonas aeruginosa wild strain). First order inactivation kinetics with respect to both the concentrations of ozone and microorganisms were found, resulting an overall second order inactivation kinetics. The ATCC strains showed to be the most sensitive toward ozone among all. Meanwhile, the environmental isolation of Pseudomonas aeruginosa was the most resistant and Escherichia coli the most sensitive wild strain. The longest time required to achieve total inactivation was 35 minutes. 相似文献
759.
Immobilization of whole viable Pseudomonas fluorescens cells was achieved on a graphite electrode modified with a thiophene-based conducting polymer. Microbial electrodes were constructed by the entrapment of bacterial cells on conducting copolymer matrix using a dialysis membrane. The biosensor was characterized using glucose as the substrate. As well as analytical characterization, effects of electropolymerization time, pH and temperature on the sensor response were examined. Finally, operational stability was also tested. 相似文献
760.
Hakryul Kim Harold W. Gardner Ching T. Hou 《Journal of the American Oil Chemists' Society》2000,77(1):95-99
The new microbial isolate Pseudomonas aeruginosa (PR3) has been reported to produce from oleic acid a new compound, 7,10-dihydroxy-8(E)-octadecenoic acid (DOD), with 10-hydroxy-8-octadecenoic acid (HOD) being a probable intermediate. The production of DOD
involves the introduction of two hydroxyl groups at carbon numbers 7 and 10, and a rearrangement of the double bond from carbons
9–10 to 8–9. It has been shown that the 8–9 unsaturation of HOD was possibly in the cis configuration. Now we report that the rearranged double bond of HOD is trans rather than cis, as determined by spectral data. Also, it was found that the 10-hydroxyl was in the S-configuration as determined by gas chromatographic separation of R- and S-isomers after preparation of the (−)-menthoxycarbonyl derivative of the hydroxyl group followed by oxidative cleavage of
the double bond and methyl esterification. This latter result coincides with our recent finding that the main final product,
DOD, is in the 7(S),10(S)-dihydroxy configuration. In addition, a minor isomer of HOD (about 3%) with the 10(R)-hydroxyl configuration was also detected. From the data obtained herein, we concluded that 10(S)-hydroxy-8(E)-octadecenoic acid is the probable intermediate in the bioconversion of oleic acid to 7(S),10(S)-dihydroxy-8(E)-octadecenoic acid by PR3. 相似文献