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Guerrieri N Scippa S Maietti M de Vincentiis M Cerletti P 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2000,125(4):342-450
Proteolytic activity was studied in the fractionated blood cells of the vanadium accumulating ascidian P. mammillata by separating the cells before measuring their activity. Cells were separated to avoid vanadocyte breakdown and subsequent vanadium diffusion into the assay medium. Our study revealed activity in the morula cell extract that was obtained by sonication and Centricon concentration. After removing part of the extract for enzyme activity assay the remainder was kept at 0 degrees C; it was later found that much of the protein in this latter fraction formed a sediment whereas the protease remained in solution. The serine-protease substrate specificity of the enzyme was measured and the results are discussed in relation to serine protease involvement in immune defense. 相似文献
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Balboni G Congiu C Onnis V Maresca A Scozzafava A Winum JY Maietti A Supuran CT 《Bioorganic & medicinal chemistry letters》2012,22(9):3063-3066
An inhibition study of several carbonic anhydrase (CA, EC 4.2.1.1) isoforms with flavones and aminoflavones, compounds possessing a rather similar scaffold with the coumarins, recently discovered inhibitors of this enzyme, is reported. The natural product flavone and some of its hydroxylated derivatives did not show time-dependent inhibition of the CAs, sign that they are not hydrolyzed within the enzyme active site as the (thio)coumarins and lactones. These compounds were low micromolar inhibitors of hCA I, II, IX and XII, with K(I)s in the range of 1.88-9.07 μM. A series of substituted 2-amino-3-phenyl-4H-chromen-4-ones, incorporating chloro- and methoxy substituents in various positions of the heterocycle, were then prepared and assayed as hCA I and II inhibitors, showing activity in the micromolar range. Some of these derivatives, as well as cis+trans resveratrol, were then assayed for the inhibition of all catalytically active mammalian CA isoforms, hCA I, II, III, IV, VA, VB, VI, VII, IX, XII, XIII, XIV and mCA XV (h=human, m=murine enzyme). These derivatives inhibited these CAs in the submicromolar-low micromolar range. Flavones, although not as active as the coumarins, may be considered as interesting leads for the design of non-sulfonamide CA inhibitors. 相似文献
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P. Romano G. Palla A. Caligiani V. Brandolini A. Maietti G. Salzano 《Biotechnology letters》2000,22(24):1947-1951
The (R)/(S) ratios of acetoin were always higher in wines obtained by Saccharomyces cerevisiae than in those obtained by Kloeckera apiculata. A significantly different behaviour was determined between the two species as regards contents and ratios of 2,3-butanediols: S. cerevisiae produced more (R,R)-2,3-butanediol (about 80%), whereas K. apiculata produced more meso-form (about 90%). 相似文献
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Phytotoxic Effects and Phytochemical Fingerprinting of Hydrodistilled Oil,Enriched Fractions,and Isolated Compounds Obtained from Cryptocarya massoy (Oken) Kosterm. Bark
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Enrico Rolli Matteo Marieschi Silvia Maietti Alessandra Guerrini Alessandro Grandini Gianni Sacchetti Renato Bruni 《化学与生物多样性》2016,13(1):66-76
The hydrodistilled oil of Cryptocarya massoy bark was characterized by GC‐FID and GC/MS analyses, allowing the identification of unusual C10 massoia lactone ( 3 , 56.2%), C12 massoia lactone ( 4 , 16.5%), benzyl benzoate ( 1 , 12.7%), C8 massoia lactone (3.4%), δ‐decalactone ( 5 , 1.5%), and benzyl salicylate ( 2 , 1.8%) as main constituents. The phytotoxic activities of the oil, three enriched fractions (lactone‐rich, ester‐rich, and sesquiterpene‐rich), and four constituents (compounds 1, 2, 5 , and δ‐dodecalactone ( 6 )) against Lycopersicon esculentum and Cucumis sativus seeds and seedlings were screened. At a concentration of 1000 μl/l, the essential oil and the massoia lactone‐rich fraction caused a complete inhibition of the germination of both seeds, and, when applied on tomato plantlets, they induced an 85 and 100% dieback, respectively. These performances exceeded those of the well‐known phytotoxic essential oils of Syzygium aromaticum and Cymbopogon citratus, already used in commercial products for the weed and pest management. The same substances were also evaluated against four phytopathogenic bacteria and ten phytopathogenic fungi, providing EC50 values against the most susceptible strains in the 100–500 μl/l range for the essential oil and in the 10–50 μl/l range for compound 6 and the lactone‐rich fraction. The phytotoxic behavior was related mainly to massoia lactones and benzyl esters, while a greater amount of 6 may infer a good activity against some phytopathogenic fungi. Further investigations of these secondary metabolites are warranted, to evaluate their use as natural herbicides. 相似文献
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Saccharomyces cerevisiae wine strains differing in copper resistance exhibit different capability to reduce copper content in wine 总被引:1,自引:0,他引:1
Brandolini V. Tedeschi P. Capece A. Maietti A. Mazzotta D. Salzano G. Paparella A. Romano P. 《World journal of microbiology & biotechnology》2002,18(6):499-503
Two wine strains of Saccharomyces cerevisiae, characterized by a different degree of copper resistance, were tested in grape must fermentation in the presence of different copper concentrations. The sensitive strain SN9 was strongly affected by copper concentration (32 ppm, (32 mg/l)), whereas the resistant strain SN41 exhibited a good growth activity in presence of 32 ppm of copper and only a reduced activity in presence of 320 ppm. The different strain fermentation performance in response to the copper addition corresponded to a different capability to accumulate copper inside the cells. Both strains exhibited the capacity to reduce the copper content in the final product, eventhough a significantly greater reducing activity was exerted by the resistant strain SN41, which was able to reduce by 90% the copper concentration in the final product and to accumulate the metal in great concentrations in the cells. As high concentrations of copper can be responsible for wine alterations, the selection of S. cerevisiae strains possessing high copper resistance and the ability to reduce the copper content of wine has a great technological interest, in particular for the fermentation of biological products. From the results obtained, the technique proposed is not only suitable for the assay of copper residues in must, wine and yeast cells, but it also offers the advantage of easy sample preparation and low detection limit in the ppb (g/l) range. 相似文献
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Brandolini V. Salzano G. Maietti A. Caruso M. Tedeschi P. Mazzotta D. Romano P. 《World journal of microbiology & biotechnology》2002,18(5):481-485
A rapid and efficient analytical method for the determination of glycerol in wines is described. This method utilizes high-performance thin layer chromatography (HPTLC) plates coupled with an automated multiple development system with an elution gradient based on acetonitrile–acetone–hexane on silica gel layers. The absence of clean-up procedures, sometimes only centrifugation, makes this method suitable also for the large-scale control of alcoholic beverages. In particular the capacity of different wine yeast species (Saccharomyces cerevisiae, Zygosaccharomyces bailii, Kloeckera apiculata and Saccharomycodes ludwigii) to produce glycerol was determined. Generally, the strains of S. cerevisiae produced elevated amounts of glycerol together with Z. bailii, whereas K. apiculata strains formed the lowest amounts of glycerol, exhibiting also a great strain variability. 相似文献
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Incidence of antibiotic resistance and virulence determinants among Enterococcus italicus isolates from dairy products 总被引:1,自引:0,他引:1
The main objective of this work was to investigate the biosafety of Enterococcus italicus, a recently described enterococcal species widely diffused in dairy products. For this purpose, the antibiotic susceptibility and the incidence of virulence factors among 30 E. italicus isolates originating mainly from different Italian cheeses were tested. Although not all 30 isolates showed unique genotypes, PCR fingerprinting evidenced a notable genotypic diversity among the E. italicus collection under study. All isolates were susceptible to vancomycin, gentamicin, erythromycin, ampicillin, chloramphenicol and bacitracin. Five isolates corresponding to three unique genotypes exhibited phenotypic resistance to tetracycline with MICs ranging from 64-256mug/ml. By PCR-based detection, the genetic basis of the Tet(R) phenotype in these strains was linked to the tet(S) gene whereas detection of tet(L) and tet(M) genes and the integrase element int of the Tn916/Tn1545 family of transposons were negative. Likewise, none of the strains appeared to contain any of the tested virulence genes gelE, asaI, cpd, agg, cylA, cylB, cylM, ace and hyl(Efm). The results of this study warrant further research into the environmental dissemination of Tet(R)E. italicus and into the potential transferability of its tet(S) genes. 相似文献
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Fantin G Giovannini PP Guerrini A Maietti S Medici A Pedrini P 《Biotechnology letters》2006,28(11):805-810
Fungi from Amazonian forest soil (Ecuador) and an Italian factory were screened for Baeyer–Villiger (BV) oxidation of bicyclo
[3.2.0]hept-2-en-6-one to 2-oxabicyclo[3.3.0]oct-6-en-3-one (Corey’s lactone). Isolates of Fusarium sp. and F. solani produced the (+)-(1R,5S)-lactone while isolates of Aspergillus terricola and A. amazonicus afforded the (−)-(1S,5R)-lactone. Highest conversions (85% yield and 70% enantiomeric excess) were obtained with A. amazonicus grown in presence of 2.7 mM titanium dioxide. 相似文献
10.
Martina Giovanardi Lorenzo Ferroni Costanza Baldisserotto Paola Tedeschi Annalisa Maietti Laura Pantaleoni Simonetta Pancaldi 《Protoplasma》2013,250(1):161-174
Neochloris oleoabundans is considered one of the most promising oil-rich microalgae because of its ability to store lipids under nitrogen starvation. However, high biomass densities, required for applications on medium to large scale, are not reached in this condition of growth. As previous studies on other microalgae have shown that mixotrophy allows to obtain higher biomass in comparison to autotrophic cultures, we performed morphophysiological analyses in order to test the mixotrophic growth capability of N. oleoabundans. A carbon-rich manure derived from the apple vinegar production (AWP) was added to the medium. Cells were also cultivated under nutrient starvation (tap water), to observe the expected lipids accumulation, and combining AWP to water, to test the potential of this waste in a low-cost culture system. The results highlighted that AWP in the medium allowed to obtain the highest final cell density. Moreover, starch granules were stored inside chloroplast at the beginning of the experiment. The presence of AWP did not induce variations on light harvesting complex II (LHCII)–photosystem II (PSII) assembly, even if an interesting promotion of pigment synthesis in cells was observed. On the other hand, in starved cells, chloroplast degeneration, pigment content decrease, altered LHCII–PSII assembly and accumulation of high amount of lipid globules were observed, irrespective of the presence of AWP. The results suggest that mixotrophy promotes growth in N. oleoabundans and open up the possibility of using waste products from agri-food industries for this purpose. After growth, cells could be transferred under nutrient starvation to induce lipid accumulation. 相似文献