Sürdürülebilir Kalkınma Amaçları

Yazarlar

  • MakaleYalnız künye2019Scopus SJRQ2
    Biosynthesis of gold nanoparticles using marine bacteria and Box–Behnken design optimization

    Camas, Mustafa; Celik, Fatih; Sazak Camas, Anil; Ozalp, Hasan Baris

    Gold nanoparticles are exciting materials because of their potential applications in optics, electronics, biomedical, and pharmaceutical fields. In recent years, environmentally friendly, low-cost biosynthesis methods with bio-applicable features have continued to be developed for the synthesis of gold nanoparticles. In the present study, an actinobacterial strain was isolated from the Petrosia ficiformis (Poiret 1798) sponge, which was collected from a marine environment, and the gold nanoparticle synthesis was performed for the first time from the bacteria type belonging to the Citricoccus genus. The synthesis conditions were optimized using the Box–Behnken experimental design, with a statistical method that included three independent variables (temperature, time, and mixture ratio) to affect the synthesis at three levels (+1, 0, and −1). Accordingly, the conditions proposed for the biosynthesis of gold nanoparticles at the maximum optical density values that are specific for the Citricoccus sp. K1D109 strain were estimated as 35°C temperature, 24 h, and 1/5 mixture ratio (cell-free extract/HAuCl4 · 3H2O). When recommended conditions were applied, it was determined that the maximum absorbance of the synthesized gold nanoparticles is 1.258 at 545 nm, and their sizes are in the range of 25–65 nm, according to transmission electron microscopy (TEM) data.

    AtıfScopus33WoS30OpenAlex34
    ScopusWeb of Scienceİncele
  • MakaleAçık Erişim2019Scopus SJRQ2
    Optimization of microwave apple drying using response surface method; [Yanit yüzey metodu kullanarak mikrodalga ile elma kurutmanin optimizasyonu]

    Yoǧurtçu, Hakan

    In this study, the effects of microwave output power and slice thickness on microwave drying of apple slices were studied by using response surface method (RSM) in a modified domestic microwave oven. For experimental design, the central composite rotatable design approach was used. The values of response variables, effective diffusion coefficient, drying rate constant, color change, Hue angle, total drying time and energy consumption, were determined from the experiments performed under design conditions. It was seen that the obtained second order polynomial equations successfully represent the response variables. The results of analysis of variance (ANOVA) and response surface curves revealed that microwave output power and slice thickness were significantly effective on response variables. The effects of the independent variables on the responses and the significance level of these effects were evaluated statistically and the optimum drying conditions were determined for the aims of min color change, total drying time, energy consumption and max Hue angle. Verification experiments were performed with a maximum of 9.54% error at the recommended optimum test conditions. It has been shown that the response surface method can be successfully applied in the microwave drying of apples.

    AtıfScopus6WoS5OpenAlex3TR Dizin3
    ScopusWeb of ScienceTR Dizinİncele
  • MakaleÖn baskısı açık2016Scopus SJRQ1
    Determination of anthocyanins in cherry and cranberry by high-performance liquid chromatography-electrospray ionization-mass spectrometry

    Karaaslan, Nagihan M.; Yaman, Mehmet

    Anthocyanins are a group of widespread natural phenolic compounds in vegetables and fruits. The anthocyanins have a wide range of applications due to the antioxidant, anticancer and anti-inflammatory properties. In this study, anthocyanins (delphinidin-3-o-glucoside, cyanidin-3-o-glucoside, pelargonidin-3-o-glucoside and malvidin-3-o-glucoside) in cherry and cranberry were determined using high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS). The anthocyanins were separated using gradient elution and a reserved-phase analytical column before identification by high-performance liquid chromatography-electrospray ionization-mass spectrometry. A high-performance liquid chromatography-electrospray ionization-mass spectrometry method was optimized for the determination of anthocyanins in cherry and cranberry. Furthermore, in this study, we investigated extraction conditions of fruit samples as well as determination of optimum HPLC-ESI-MS conditions. This study is novel in terms of simultaneously examining both optimization of HPLC parameters and extraction conditions. Obtained optimum conditions were used for the determination as the quantitative and qualitative analysis of anthocyanins in cherry and cranberry. The content of anthocyanins on the basis of wet weight in cherry and cranberry samples was determined for delphinidin-3-o-glucoside < d.l. (detection limit) and < d.l., for cyanidin-3-o-glucoside varied from 3.5 +/- A 0.4 to 8.3 +/- A 1.1 mg kg(-1) (average 5.8 +/- A 0.8 mg kg(-1)) and 9.8 +/- A 1.4 to 18 +/- A 3.0 mg kg(-1) (average 13.2 +/- A 1.8 mg kg(-1)), for pelargonidin-3-o-glucoside < d.l. and varied from 136 +/- A 19 to 233 +/- A 35 mg kg(-1) (average 185.3 +/- A 28 mg kg(-1)), for malvidin-3-o-glucoside < d.l. and < d.l., respectively.

    • SDG 2 · Açlığa Son
    AtıfWoS25OpenAlex29
    Web of Scienceİncele
  • MakaleAçık Erişim2015Scopus SJRQ4
    Optimization of lipase production on agro-industrial residue medium by Pseudomonas fluorescens (NRLL B-2641) using response surface methodology

    Tanyol, Mehtap; Uslu, Gulsad; Yönten, Vahap

    The aim of our research was to explore the most cost-efficient and optimal medium composition for the production of lipase from Pseudomonas fluorescens (NRLL B-2641) culture grown on sunflower oil cake (SuOC) by applying response surface methodology (RSM). The oil cake was used instead of carbon sources. Peptone, ammonium sulphate and the carbon source (SuOC) were the most important factors as it is obligatory for microbial growth. Subsequently, the optimum values for the carbon source, peptone and ammonium sulphate were found to be 11.10% (w/v), 1.18% (w/v) and 0.83% (w/v), respectively. Experiments carried out under optimum conditions revealed a maximum lipase activity of 10.8 U mL(-1), which was achieved after 48 h of fermentation. The obtained results were finally verified with batch experiments carried out under the optimum conditions evaluated and it was demonstrated that the SuOC from agro-industrial residue as substrates can be used as an inexpensive base (carbon source) for the production of lipase by P. fluorescens (NRLL B-2641).

    AtıfWoS19
    Web of Scienceİncele
  • MakaleAçık Erişim2015Scopus SJRQ3
    Automatic Mining of Numerical Classification Rules with Parliamentary Optimization Algorithm

    Kiziloluk, Soner; Alatas, Bilal

    In recent years, classification rules mining has been one of the most important data mining tasks. In this study, one of the newest social-based metaheuristic methods, Parliamentary Optimization Algorithm (POA), is firstly used for automatically mining of comprehensible and accurate classification rules within datasets which have numerical attributes. Four different numerical datasets have been selected from UCI data warehouse and classification rules of high quality have been obtained. Furthermore, the results obtained from designed POA have been compared with the results obtained from four different popular classification rules mining algorithms used in WEKA. Although POA is very new and no applications in complex data mining problems have been performed, the results seem promising. The used objective function is very flexible and many different objectives can easily be added to. The intervals of the numerical attributes in the rules have been automatically found without any a priori process, as done in other classification rules mining algorithms, which causes the modification of datasets.

    AtıfWoS12OpenAlex18
    Web of Scienceİncele
  • MakaleYalnız künye2014Scopus SJRQ3
    EXPLORING THE OPTIMUM CONDITIONS FOR MAXIMIZING THE MICROBIAL GROWTH OF Candida intermedia BY RESPONSE SURFACE METHODOLOGY

    Yönten, Vahap; Aktas, Nahit

    Exploring optimum and cost-efficient medium composition for microbial growth of Candida intermedia Y-1981 yeast culture growing on whey was studied by applying a multistep response surface methodology. In the first step, Plackett-Burman (PB) design was utilized to determine the most significant fermentation medium factors on microbial growth. The medium temperature, sodium chloride and lactose concentrations were determined as the most important factors. Subsequently, the optimum combinations of the selected factors were explored by steepest ascent (SA) and central composite design (CCD). The optimum values for lactose and sodium chloride concentrations and medium temperature were found to be 18.4g/L, 0.161g/L, and 32.4 degrees C, respectively. Experiments carried out at the optimum conditions revealed a maximum specific growth rate of 0.090 1/hr; 42% of total lactose removal was achieved in 24h of fermentation time. The obtained results were finally verified with batch reactor experiments carried out under the optimum conditions evaluated.

    AtıfWoS14OpenAlex16
    Web of SciencePubMedİncele
  • MakaleYalnız künye2013Scopus SJRQ2
    DETECTING OPTIMUM AND COST-EFFICIENT OF MICROBIAL GROWTH RATE AND LACTOSE CONSUMPTION OF KLUYVEROMYCES LACTIS Y-8279 USING RSM

    Yönten, Vahap

    Exploring optimum and cost-efficient medium composition for microbial growth rate and lactose consumption of Kluyveromyces Lactis Y-8279 yeast culture growing on whey was studied by applying a multi-step response surface methodology (RSM). RSM is a combination of Plackett Burman (PB), Steepest-Ascent (SA) and Central Composite Design (CCD) Medium temperature, pH, yeast extract and lactose concentrations were evaluated the most effective operational factors through seven factors by applying PBD. These four factors were selected for SA program and SA experiments were carried out to find approximately maximum microbial concentration with lactose, pH, yeast extract and medium temperature. Then CCD was carried out with these factors (lactose, medium temperature, pH and yeast extract). Based on ANOVA test the optimum operational conditions of maximum growth rate were obtained as 18.8 g/L, 0.94 g/L, 5.2 and 27 degrees C, lactose concentration, yeast extract concentration, pH, and medium temperature, respectively. And then optimum operational conditions of lactose consumption were obtained as 13 g/L, 0.91 g/L, 8 and 27.5 degrees C, lactose concentration, yeast extract concentration, pH, and medium temperature, respectively too.

    AtıfWoS1
    Web of Scienceİncele