Cristina Abbate
University of Catania
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Featured researches published by Cristina Abbate.
Arid Land Research and Management | 2007
Mara Gennari; Cristina Abbate; Vincenza La Porta; Andrea Baglieri; Alessandro Cignetti
We studied the effects of increased electrical conductivity (EC) of a soil on the activity and structure of its microbial community. Dry soil samples were added with 0, 11, 22, and 45 g kg−1 of Na2SO4 and left to incubate for 40 d before microbial respiration, microbial biomass C (MBC), microbial biomass N (MBN), K2SO4-extractable C (Ext-C), K2SO4-extractable N (Ext-N), and potentially mineralizable N (PMN) were determined. Amplified ribosomal DNA restriction analysis (ARDRA) and denaturing gradient gel electrophoresis (DGGE) were applied on α-, β-proteobacterial, and actinomycete 16S rDNA fragments amplified by PCR from total DNA in order to better understand the effect of osmotic stress on the soil microbial communities. The increase in EC significantly reduced respiratory activity of the microbial biomass and lowered microbial C; moreover, it increased the soluble fraction of both C and N. Greater N mineralization was found in soils to which 11 and 22 g kg−1 of Na2SO4 had been added as compared with both the untreated soil, and that receiving 45 g kg−1 of Na2SO4. The two former soils were also richer in aerobic bacteria (107 CFU g−1 soil) than the other two soils (106 CFU g−1 soil), and the ARDRA and DGGE analyses showed an activation of the α-proteobacteria. No significant differences were found in the ARDRA and DGGE patterns of the β-proteobacteria and actinomyces groups, suggesting a no-detectable response of these microorganisms to the Na2SO4 addition within the concentration range in this study.
Journal of Hazardous Materials | 2009
Cristina Abbate; Maria Arena; Andrea Baglieri; Mara Gennari
The aim of this study was to evaluate the effects of the commercial organoclays, CLOISITE 30B, NANOFIL 804 and DELLITE 26C on soil eubacterial community. An enrichment test was carried out on Nutrient Broth containing the organoclay and the microorganisms previously isolated from soil. Four transfers were made, each after 7 days incubation. The molecular analyses on the eubacterial community were performed before treatment and 7 days after each transfer. DNA was extracted, amplified with eubacterial primers, finally analysed by amplified ribosomal DNA restriction analysis (ARDRA) and denaturing gradient gel electrophoresis (DGGE). The profiles of the samples treated with each organoclay showed the absence, the appearance and an increase in the intensity of some bands. These bands were excised from the gels, and the related microorganisms were identified by DNA sequencing, as Pseudomonas putida, Alcaligenes xylosoxidans, Pseudomonas monteilii and Pseudomonas aeruginosa. NAN804 treatment did not have any influence on soil eubacterial community, CLO30B had a slight toxic effect only on P. putida, instead the DEL26C treatment had a stronger toxic effect on P. putida and a slight toxic effect on P. monteilii. Finally, all the tested organoclays stimulated the growth of both A. xylosoxidans and P. aeruginosa.
Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes | 2007
Cristina Abbate; Daniela Borzì; Pierluigi Caboni; Andrea Baglieri; Mara Gennari
A study was conducted to investigate fenhexamid (FEX) behavior in soil and in water. FEX proved to be rather stable at acid pH but showed slight degradation at neutral and alkaline pH. After 101 days of FEX spiking of a soil sample, 94% at pH 4, 12% at pH 7 and 23% at pH 9 of the active ingredient was still present. In natural water the rate of FEX disappearance appeared to be slow which may be due to abiotic rather than biotic processes. The soil degradation tests showed low persistence of the active ingredient if a good microflora activity is guaranteed (DT50 about 1 day). Moreover, in absence of microorganisms, FEX proved to be stable. Humidities of 25 and 50% of Water Holding Capacity (WHC) influenced in equal measure the rate of degradation. From the same soil, a bacterium was isolated and identified as Bacillus megaterium, which was able to metabolize FEX with the hydroxylation of the cyclohexane ring. Moreover, FEX showed an elevated affinity for humic acid (73%), smectite (31%), and ferrihydrite(20%) and low affinity for vermiculite (11%) and kaolinite (7%).
Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes | 2009
Andrea Baglieri; Daniela Borzì; Cristina Abbate; Michèle Negre; Mara Gennari
The ability of a sodium montmorillonite (CLONa) and two commercial available organoclays having interlayer organic cations possessing different functional groups (CLO20A and CLO30B) was investigated for adsorbing two pesticides namely fenexamid (FEX) and pyrimethanyl (PMT). The two organoclays displayed a higher affinity with the pesticides than the unmodified clay, but the improvement in adsorption capacity varied according to the characteristics of the pesticide and the interlayer organic cation. FEX was adsorbed to a greater extent than PMT by both organoclays, which may be due to the higher hydrophobicity of FEX thereby indicating considerable hydrophobic interaction between the adsorbent/adsorbate systems. Our findings may find application in the removal of water-soluble pesticides from aquifers.
Journal of Environmental Science and Health Part A-toxic\/hazardous Substances & Environmental Engineering | 2008
Michele Negre; Carlotta Boursier; Cristina Abbate; Andrea Baglieri; Mara Gennari
The effects of cyanobacteria aqueous extracts containing Microcystin-LR (MC-LR) on the seed germination and growth of Pisum sativum, Lens esculenta, Zea mays and Triticum durum were investigated. Experiments were carried out on a range of doses of the extract (equivalent to 0, 1.6, 2.9, 5.8, 8.7 and 11.6 mu g MC-LR/mL). The results confirm that these plants were sensitive to cell-free extracts of a toxic Microcystis and that germination inhibition was dose dependent. One-way analysis of variance (ANOVA) showed that P. sativum is the most sensitive tested species with a 97% germination rate reduction and L. esculenta was the most resistant. At the 8th day, the exposure to the microcystins (MC) resulted in a significant decrease of plant epicotyls length, roots length and a net inhibition of lateral root formation. It is concluded that MC could affect also terrestrial plants seedling germination and growth. Therefore, the use of water for irrigation contaminated by MC could exert negative biochemical effects on seed and plant metabolism which might influence the agricultural crops.
International Journal of Environmental Analytical Chemistry | 2007
Daniela Borzì; Cristina Abbate; Fabrice Martin-Laurent; Najoi El Azhari; Mara Gennari
The aim of this work was to evaluate the impact of the fungicide fenhexamid (FEX) on the genetic structure of soil bacterial communities using the Ribosomal Intergenic Spacer Analysis molecular technique. Using real-time PCR, we also tried to quantify the pcaH sequences which encode the dioxygenases involved in the degradation process of a variety of aromatic compounds. Soil taken from a vineyard in the Etna Park (Sicily, Italy) was treated with FEX in the ratio 2 µg g−1 soil every 7 days, the process being repeated four times. The analyses were carried out before treatment and 7 days after each further application of FEX. At the same time, the degradation rate was evaluated. The use of FEX determined a variation in the bacterial component of the soil which could be seen in an increase of some microbial strains and the inhibition of others. The pcaH sequence was already present in the genes of the soil microrganisms studied, but the use of FEX increased the number of the gene copies. These results suggest that the microbial population of the soil adapted to the presence of FEX with an increase in degradation potential. The measurements of the extent to which FEX was degraded confirm this hypothesis, showing that the molecule disappeared more quickly with successive applications.
Applied Biochemistry and Biotechnology | 2002
Riccardo N. Barbagallo; Giovanni Spagna; Cristina Abbate; Giuseppe Azzaro; Rosa Palmeri
Abstractβ-d-Glucopyranosidase (βG, EC 3.2.1.21) has been isolated from some collateral activities, α-l-arabinofuranosidase (Ara, EC3.2.1.55), α-l-rhamnopyranosidase (Rha, EC 3.2.1.40), and o-acetylesterase (Est, EC 3.1.1.53), using a commercial enzyme preparation and a simple method economically sustainable for the food industry. The procedure comprises precipitation of extraneous substances by adding ethanol and CaCl2, ultrafiltration, and adsorption, first on bentonite and then on chitosan. The results obtained were the complete isolation of βG from the above-mentioned activities, a drastic reduction in extraneous compounds, such as brown substances and polysaccharides, and a slight increase in purification.
Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes | 2009
Mara Gennari; Cristina Messina; Cristina Abbate; Andrea Baglieri; Carlotta Boursier
In the present work changes in the adsorption of the pesticide chlorpyrifos-methyl (CLP-m) on soil colloids induced by application of surfactants were determined using a batch equilibrium method. The surfactants used were sodium dodecyl sulphate (SDS), Tween 20, and dihexadecyldimethylammonium bromide (DHAB). The adsorption isotherms of CLP-m in aqueous medium and in surfactant solutions at concentration equal to the critical micelle concentration (CMC) fitted the Freunlich adsorption equation generally with R2 values greater than 0.96. While the addition of SDS and DHAB decreased the pesticide adsorption, the addition of Tween 20 increased the pesticide adsorption. The increases or decreases in the adsorption in the experiment revealed that the behavior of CLP-m in soil water-systems mainly depends on the type of surfactant. Moreover water solubility of CLP-m changes by the three surfactants below and above their CMC were studied. While the solubility of CLP-m was enhanced by SDS both below and above the CMC, the solubility of the pesticide was enhanced by DHAB only above the CMC. Tween 20 did not influence the solubility of CLP-m.
Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes | 2008
Mara Gennari; Cristina Abbate; Andrea Baglieri; Michèle Negre
The behavior and fate of triasulfuron (TRS) in water and soil systems were examined in laboratory studies. The degradation of TRS in both buffer solution and soil was highly pH-sensitive. The rate of degradation could be described with a pseudo first-order kinetic and was much faster at pH 4 than at pH 7 and 9. Aqueous hydrolysis occurred by cleavage of the sulfonylurea bridge to form 2-(2-chloroethoxy) benzenesulfonamide (CBSA) and [(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino] (AMMT). AMMT was unstable in aqueous solutions in any pH condition but it degraded more quickly at pH 4 and 9. CBSA did not degrade in aqueous solutions or in enriched cultures but it underwent a quick degradation in the soil. The rates of TRS degradation in sterile and non-sterile soils were similar, suggesting that microorganisms played a minimal role in the breakdown process. This hypothesis is supported by the results of studies on the degradation of TRS by enriched cultures during which the molecule underwent a prevalently chemical degradation.
Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes | 2011
Andrea Baglieri; Mara Gennari; Maria Arena; Cristina Abbate
To evaluate the feasibility of using compost to prepare substrates for the disposal of pesticide residues, adsorption and degradation studies were carried out on three widely used agricultural pesticides: chlorpyriphos-methyl, pendimethalin and metalaxyl. Obtained from solid urban waste, this compost has been shown to be able to adsorb high levels of chlorpyriphos-methyl and pendimethalin (85 %, 100 %) whereas metalaxyl was only adsorbed at a level of 37 %. However, adding smectite to the compost increased the adsorption of metalaxyl by 117 %. Chlorpyriphos-methyl and pendimethalin degraded quickly with half-lives of 1.7 and 14.5 days, respectively, whereas metalaxyl proved more persistent (a half-life of 84 days). Adding ammonium nitrate to the compost accelerated metalaxyl degradation to a half-life of 15 days.