100 research outputs found

    The Embioptera from the Strait of Sicily Islands: first records from Pantelleria and Lampedusa and new data from Lampione (Sicily, Italy)

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    The occurrence of Embioptera in the Strait of Sicily islands was up to date known only from Lampione (the smallest of the Pelagie islands), where the only species reported was provisionally assigned to Embia ramburi Rimski-Korsakow, 1905. Based on material recently collected by the authors, the presence of Embioptera is here reported for the first time in the Islands of Pantelleria (Sicily, Trapani) and Lampedusa (Sicily, Agrigento). In the Island of Pantelleria the occurrence of the typical small silky tunnels produced by Embioptera has been verified in many sites, from sea level to Montagna Grande (836 m). In many of these sites, several juveniles and some adult or subadult specimens were collected and reared, obtaining an adult male belonging to Cleomia guareschii Stefani, 1953. Moreover, a single adult male of E. ramburi was collected in Lampedusa, the largest of the Pelagian Islands. Finally, the fauna of Embioptera from Lampione remains still poorly known, as it was possible to examine only two females recently collected in the island, and identified as Embia sp

    Biological activity of Bacillus spp. evaluated on eggs and larvae of red palm weevil Rhynchophorus ferrugineus

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    This study was conducted to characterize the Bacillus populations associated with dead Rhynchophorus ferrugineus, to develop a biological control for the red palm weevil. Dead adult beetles, collected throughout Sicily, were used for isolating internal and external spore forming bacteria (SFB) microbiota. The isolates, preliminarily allotted to the Bacillaceae family, were tested at 4 concentrations (103 to 106 CFU/mL) for their ability to inhibit hatching of eggs of R. ferrugineus and were used at 106 CFU/mL to monitor their insecticidal activity against 10 day-old larvae. Total amounts of SFB measured outside the skeleton and in the inners part of the beetles were 5.59-6.94 and 5.17-7.05 Log CFU/g, respectively. Hatching was inhibited markedly by 9 isolates, representing 9 distinct strains of 7 species (Bacillus amyloliquefaciens, Bacillus cereus, Bacillus licheniformis, Bacillus megaterium, Bacillus pumilus, Bacillus subtilis, and Lysinibacillus sphaericus), especially by the strains B. pumilus GC43 and GC51, which exhibited lethal concentrations 50 (LC50) values of 1.60 × 103 and 9.84 × 103 CFU/mL, respectively. Among all the strains tested, only B. licheniformis CG62 exhibited significant insecticidal activity against red palm weevil larvae. The Bacillus isolates characterized and tested in this study inhibited the hatching of red palm weevils in a contact-dependent manner. Thus, these isolates can be used as a preventive rather than as a curative treatment. Keywords Bacillus, Rhynchophorus ferrugineus, hatching assays, larvae, Pal

    Hydrolysis of Chlorogenic Acid in Sunflower Flour Increases Consumer Acceptability of Sunflower Flour Cookies by Improving Cookie Color

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    Sunflower meal, a byproduct of sunflower oil pressing, is not commonly used in alkaline baking applications. This is because chlorogenic acid, the main phenolic antioxidant in sunflower seeds, reacts with protein, giving the baked product a green discoloration. Our group previously demonstrated that a chlorogenic acid esterase from Lactobacillus helveticus hydrolyzes chlorogenic acid in sunflower dough cookie formulations, resulting in cookies that were brown instead of green. This study presents a sensory analysis to determine the acceptability of enzymatically upcycled sunflower meal as an alternative protein source for those allergic to meals from legumes or tree nuts. We hypothesized that the mechanism of esterase-catalyzed chlorogenic acid breakdown does not influence the cookies’ sensory properties other than color and that consumers would prefer treated, brown cookies over non-treated cookies. Cookies made from sunflower meal were presented under green lights to mask color and tested by 153 panelists. As expected, the sensory properties (flavor, smell, texture, and overall acceptability) of the treated and non-treated cookies were not statistically different. These results corroborate proximate analysis, which demonstrated that there was no difference between enzymatically treated and non-treated cookies other than color and chlorogenic acid content. After the cookie color was revealed, panelists strongly preferred the treated cookies with 58% indicating that they “probably” or “definitely” would purchase the brown cookies, whereas only 5.9% would buy green, non-treated cookies. These data suggest that esterase-catalyzed breakdown of chlorogenic acid represents an effective strategy to upcycle sunflower meal for baking applications

    Preventing Chlorogenic Acid Quinone-Induced Greening in Sunflower Cookies by Chlorogenic Acid Esterase and Thiol-based Dough Conditioners

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    Sunflower seeds contain a high concentration of chlorogenic acid (CGA), which reacts with amino acids to form green pigments under alkaline conditions during food processing. Here, we present two approaches to prevent green pigment formation in sunflower cookies by (A) Addition of free thiols from cysteine and glutathione to sunflower cookie dough and (B) hydrolyzing CGA into caffeic acid and quinic acid with a CGA esterase from Lactobacillus helveticus. Greening occurred more slowly with cysteine; however, neither cysteine nor glutathione prevented greening in the cookies during storage. Chlorogenic acid esterase hydrolyzed CGA in both sunflower butter and flour, resulting in the complete elimination of greening in the sunflower cookies. CGA esterase treatment was efficient as the enzyme could be applied in low amounts (\u3c100 ppm) directly to the dough without needing to pretreat either sunflower butter or flour. Overall, our data indicate that CGA esterase treatment was an effective method of eliminating unwanted greening in sunflower cookies made with baking soda. Long term, these results may represent a method of increasing the use of sunflower butter and flour in high pH baking applications by enabling their use in neutrally colored baked products such as cookies and muffins

    Recent developments on precision beekeeping: A systematic literature review

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    The aim of this systematic review was to point out the current state of precision beekeeping and to draw implications for future studies. Precision beekeeping is defined as an apiary management strategy based on monitoring individual bee colonies to minimize resource consumption and maximize bee productivity. This subject that has met with a growing interest from researchers in recent years because of its environmental implications. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) was selected to conduct this review. The literature search was carried out in the Scopus database for articles published between 2015 and 2023, being a very recent issue. After two rounds screening and examination, 201 studies were considered to be analysed. They were classified based on the internal parameters of the hive, in turn divided by weight, internal temperature, relative humidity, flight activity, sounds and vibrations, gases, and external parameters, in turn divided by wind speed, rainfall and ambient temperature. The study also considered possible undesirable effects of the use of sensors on bees, economic aspects and applications of Geographic Information System technologies in beekeeping. Based on the review and analysis, some conclusions and further directions were put forward

    A Highly Active Esterase from \u3cem\u3eLactobacillus helveticus\u3c/em\u3e Hydrolyzes Chlorogenic Acid in Sunflower Meal to Prevent Chlorogenic Acid Induced Greening in Sunflower Protein Isolates

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    Chlorogenic acid (CGA) is an ester between caffeic and quinic acid. It is found in many foods and reacts with free amino groups in proteins at alkaline pH, leading to the formation of an undesirable green pigment in sunflower seed-derived ingredients. This paper presents the biochemical characterization and application of a highly active chlorogenic acid esterase from Lactobacillus helveticus. The enzyme is one of the most active CGA esterases known to date with a Km of 0.090 mM and a kcat of 82.1 s−1. The CGA esterase is easily expressed recombinantly in E. coli in large yields and is stable over a wide range of pH and temperatures. We characterized CGA esterase’s kinetic properties in sunflower meal and demonstrated that the enzyme completely hydrolyzes CGA in the meal. Finally, we showed that CGA esterase treatment of sunflower seed meal enables the production of pale brown sunflower protein isolates using alkaline extraction. This work will allow for more widespread use of sunflower-derived products in applications where neutrally-colored food products are desired

    A new signature of primordial non-Gaussianities from the abundance of galaxy clusters

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    The evolution with time of the abundance of galaxy clusters is very sensitive to the statistical properties of the primordial density perturbations. It can thus be used to probe small deviations from Gaussianity in the initial conditions. The characterization of such deviations would help distinguish between different inflationary scenarios, and provide us with information on physical processes which took place in the early Universe. We have found that when the information contained in the galaxy cluster counts is used to reconstruct the dark energy equation of state as a function of redshift, assuming erroneously that no primordial non-Gaussianities exist, an apparent evolution with time in the effective dark energy equation of state arises,characterized by the appearance of a clear discontinuity.Comment: 6 pages, 4 figures,1 table, as accepted for publication in MNRA

    CowN Sustains Nitrogenase Turnover in the Presence of the Inhibitor Carbon Monoxide

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    Nitrogenase is the only enzyme capable of catalyzing nitrogen fixation, the reduction of dinitrogen gas (N2) to ammonia (NH3). Nitrogenase is tightly inhibited by the environmental gas carbon monoxide (CO). Nitrogen-fixing bacteria rely on the protein CowN to grow in the presence of CO. However, the mechanism by which CowN operates is unknown. Here, we present the biochemical characterization of CowN and examine how CowN protects nitrogenase from CO. We determine that CowN interacts directly with nitrogenase and that CowN protection observes hyperbolic kinetics with respect to CowN concentration. At a CO concentration of 0.001 atm, CowN restores nearly full nitrogenase activity. Our results further indicate that CowN’s protection mechanism involves decreasing the binding affinity of CO to nitrogenase’s active site approximately tenfold without interrupting substrate turnover. Taken together, our work suggests CowN is an important auxiliary protein in nitrogen fixation that engenders CO tolerance to nitrogenase

    The Atacama Cosmology Telescope: Cosmological Parameters from the 2008 Power Spectra

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    We present cosmological parameters derived from the angular power spectrum of the cosmic microwave background (CMB) radiation observed at 148 GHz and 218 GHz over 296 deg^2 with the Atacama Cosmology Telescope (ACT) during its 2008 season. ACT measures fluctuations at scales 500<l<10000. We fit a model for the lensed CMB, Sunyaev-Zel'dovich (SZ), and foreground contribution to the 148 GHz and 218 GHz power spectra, including thermal and kinetic SZ, Poisson power from radio and infrared point sources, and clustered power from infrared point sources. The power from thermal and kinetic SZ at 148 GHz is estimated to be B_3000 = 6.8+-2.9 uK^2, where B_l=l(l+1)C_l/2pi. We estimate primary cosmological parameters from the 148 GHz spectrum, marginalizing over SZ and source power. The LCDM cosmological model is a good fit to the data, and LCDM parameters estimated from ACT+WMAP are consistent with the 7-year WMAP limits, with scale invariant n_s = 1 excluded at 99.7% CL (3sigma). A model with no CMB lensing is disfavored at 2.8sigma. By measuring the third to seventh acoustic peaks, and probing the Silk damping regime, the ACT data improve limits on cosmological parameters that affect the small-scale CMB power. The ACT data combined with WMAP give a 6sigma detection of primordial helium, with Y_P = 0.313+-0.044, and a 4sigma detection of relativistic species, assumed to be neutrinos, with Neff = 5.3+-1.3 (4.6+-0.8 with BAO+H0 data). From the CMB alone the running of the spectral index is constrained to be dn/dlnk = -0.034 +- 0.018, the limit on the tensor-to-scalar ratio is r<0.25 (95% CL), and the possible contribution of Nambu cosmic strings to the power spectrum is constrained to string tension Gmu<1.6 \times 10^-7 (95% CL).Comment: 20 pages, 13 figures. Submitted to ApJ. This paper is a companion to Hajian et al. (2010) and Das et al. (2010
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