Browsing by Subject "Aspergillus niger"

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    Effects of alternative current heating treatment on Aspergillus niger, pectin methylesterase and pectin content in tomato
    (2006) Yildiz H.; Baysal T.
    The main purpose of using alternative current (AC) heating treatment is to inactivate enzymes and microorganisms. The inactivation of pectin methylesterase (PME) and Aspergillus niger, and the changes in total pectin content by AC heating with different electric field strengths in the range of 36-108 V/cm for different treatment times in tomato fruit were investigated. PME activity decreased with an increase in treatment time at 108 V/cm. However PME activity increased by AC treatment at 48 V/cm for 5 s and at 36 V/cm for 5, 10, 15, and 30 s. compared to untreated control. The highest amount of total pectin was determined as 3.56% at 89 °C by AC treatment at 36 V/cm for 80 s. The A. niger inactivation was increased with increase in electric field strength and increased temperature. The concentration of A. niger (cfu/g) was determined to be <10 at 108, 68, 48, and 36 V/cm electric field strengths for the treatment times of 6, 12, 20 and 30 s, respectively. © 2005 Elsevier Ltd. All rights reserved.
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    Determination of microfungi Flora of soil polluted by industrial wastewater in Aydın, İzmir and Manisa city; [Aydın, İzmir ve Manisa i̇llerinde endüstriyel atıksular ile kirlenmiş toprakların mikrofungus Florasının belirlenmesi]
    (Cevkor Vakfi, 2011) Başbülbül G.; Biyik H.; Kalyoncu F.; Kalmiş E.; Oryaşin E.
    In this study, soil samples of 14 different localities polluted with industrial wastewaters around Aydi{dotless}n, İzmir and Manisa City were taken with seasonal intervals. The samples were brought to the laboratory and their microfungi were isolated and identified. The most frequently isolated genus from soil samples was found to be Aspergillus, followed by genus Penicillium. Among the isolated microfungi, Aspergillus niger is the most abundant species in soil. Microfungal concentrations of soil samples varied between 3,8 × 101 and 1,86 × 105 cfu/g. Depending on seasons, salinity of stations were measured between 0.004% and 0.56%, pH were between 6.36 and 9.81 and organic matter were between 0.13% and 29.15.
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    Biological decolorization of textile dyes from isolated microfungi
    (Triveni Enterprises, 2012) Biyik H.; Basbulbul G.; Kalyoncu F.; Kalmis E.; Oryasin E.
    In this study, biological decolorization of two textile dyestuff (Benazol black ZN and Cibacron black W-NN) was comparatively studied using 22 microfungi strains isolated from polluted industrial soil areas. The initial dye concentrations in the medium were 250 and 500 mg l-1. Benazol black ZN was the best decolorized by Haematonectria haematococca (HH1) (36.0%) and Cibacron black W-NN was the best decolorized by Aspergillus niger (AN1) (33.0%) at 250 mg l-1 dye concentration. At 500 mg l-1 dye concentration for two different dyes all microfungi strains used showed weak decolorization rates, maximum 13.0% for Benazol black ZN and 6.0% for Cibacron Black W-NN. © 2011 Triveni Enterprises.
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    Immobilization of amyloglucosidase onto macroporous cryogels for continuous glucose production from starch
    (Taylor and Francis Inc., 2015) Uygun M.; Akduman B.; Ergönül B.; Aktaş Uygun D.; Akgöl S.; Denizli A.
    Poly(methyl methacrylate-glycidyl methacrylate) [Poly(MMA-GMA)] cryogels were synthesized using monomers of methylmethacrylic acid and epoxy group bearing GMA via radical cryopolymerization technique. Synthesized cryogels were used for the immobilization of amyloglucosidase to the cryogel surface using epoxy chemistry. Characterizations of the free and immobilized amyloglucosidase were carried out by comparing the optimum and kinetic parameters of enzymes. For this, pH and temperature profiles of free and immobilized preparation were studied and, it was found that, optimum pH of enzyme was not change upon immobilization (pH 5.0), while optimum temperature of the enzyme shifted 10 °C to warmer region after immobilization (optimum temperatures for free and immobilized enzyme were 55 and 65 °C, respectively). Kinetic parameters of free and immobilized enzyme were also investigated and Km values of free and immobilized amyloglucosidase were found to be 2.743 and 0.865 mg/mL, respectively. Vmax of immobilized amyloglucosidase was found to be (0.496 mol/min) about four times less than that of free enzyme (2.020 mol/min). Storage and operational stabilities of immobilized amyloglucosidase were also studied and it was showed that immobilized preparation had much more stability than free preparation. In the present work, amyloglucosidase immobilized poly(MMA-GMA) cryogels were used for continuous glucose syrup production from starch for the first time. Efficiency of immobilized enzyme was investigated and released amount of glucose was found to be 2.54 mg/mL at the end of the 5 min of hydrolysis. The results indicate that the epoxy functionalized cryogels offer a good alternative for amyloglucosidase immobilization applications with increased operational and thermal stability, and reusability. Also, these cryogels can be used for immobilization of other industrially valuable enzymes beyond amyloglucosidase. © 2015 Taylor & Francis.