Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2024Scopus SJRQ3/r/bayburt/13154
  Optimization of asymmetric bioreduction conditions of 1-indanone by Leuconostoc mesenteroides N6 using a face-centered design-based multi-objective optimization model

  Alamoudi, Mohammed; Özdemir, Akın; Dertli, Enes; Bolubaid, Mohammed; Alidrisi, Hassan M.; Taylan, Osman; Yılmaz, Mustafa Tahsin; Şahin, Engin

  There has been an increasing interest in biocatalysts over the past few decades in order to obtain high efficiency, high yield, and environmentally benign procedures aiming at the manufacture of pharmacologically relevant chemicals. Lactic Acid Bacteria (LAB), a microbial group, can be employed as biocatalysts while performing asymmetric reduction of prochiral ketones. In this study, Leuconostoc mesenteroides N6 was used for the asymmetric bioreduction 1-indanone. And then, a novel and innovative face-centered design-based multi-objective optimization model was used to optimize experimental conditions. Also, the experimental design factors were defined as agitation speed, incubation period, pH, and temperature for optimization to acquire the maximum enantiomeric excess (ee) and conversion rate (cr) values. When using the face-centered design-based multi-objective optimization model, the optimum culture conditions corresponded to 96.34 and 99.42%, ee and cr responses, respectively, were pH = 5.87, incubation temperature = 35 °C, incubation period = 50.88 h, and agitation speed = 152.60 rpm. Notably, the validation experiment under the optimum model conditions confirmed the model results. This study demonstrated the importance of the optimization and the efficiency of the face-centered design-based multi-objective model.

  AtıfScopus1·WoS9·OpenAlex1

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• MakaleAçık Erişim2023Scopus SJRQ3/r/bayburt/13050
  Isolation and characterization of yogurt starter cultures from traditional yogurts and growth kinetics of selected cultures under lab-scale fermentation

  Kayacan Çakmakoğlu, Selma; Vurmaz, Melike; Bezirci, Emine; Kaya, Yasemin; Dikmen, Hilal; Göktaş, Hamza; Demirbaş, Fatmanur; Encu, Betül; Acar Soykut, Esra; Alemdar, Filiz

  The development of new starter cultures is a crucial task for the food industry to meet technological requirements and traditional products are important reservoirs for new starter cultures. In this respect, this study aimed to isolate, identify, and determine the technological characteristics of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus strains originated from traditional yogurt samples. Genotypic discrimination of 200 isolates revealed the presence of distinct 19 S. thermophilus and 11 Lb. delbrueckii subsp. bulgaricus strains as potential starter cultures. Strain-specific properties determined the acidification capacity of the yogurt starter cultures and a higher acidification capacity was observed for S. thermophilus strains compared to Lb. delbrueckii subsp. bulgaricus strains. Proteolytic activity was found between 0.012–0.172 and 0.078–0.406 for S. thermophilus and Lb. delbrueckii subsp. bulgaricus strains, respectively. 4 of S. thermophilus and 3 of Lb. delbrueckii subsp. bulgaricus strains were found resistant to all tested bacteriophages. The antibiotic susceptibility tests of the isolates revealed that a very low antibiotic resistance was observed for the yogurt starter cultures. Finally, the growth kinetics of selected strains were determined and the maximum specific growth rate of selected S. thermophilus and Lb. delbrueckii subsp. bulgaricus was calculated as 0.527 h−1 and 0.589 h−1, respectively.

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  AtıfScopus8·WoS10·OpenAlex11

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• MakaleAçık Erişim2023Scopus SJRQ3/r/bayburt/11617
  Optimization of asymmetric bioreduction conditions of 1-(thiophen-2-yl)ethanone by Weissella cibaria N9 using a desirability function-embedded face-centered optimization model

  Bolubaid, Mohammed; Özdemir, Akın; Dertli, Enes; Alamoudi, Mohammed; Taylan, Osman; Karaboğa, Derviş; Yılmaz, Mustafa Tahsin; Şahin, Engin

  Prochiral ketones can be effectively bio-reduced to chiral secondary alcohols by whole-cell biocatalysts, which are possible useful precursors to synthesize physiologically active chemicals and natural products. When whole-cell biocatalysts strains are used, bioreduction process can be influenced by various cultural factors, and it is vital to optimize these factors that affect selectivity, conversion rate, and yield. In this study, Weissella cibaria N9 was used as whole-cell biocatalyst for bioreduction of 1-(thiophen-2-yl)ethanone, and cultural design factors were optimized using a desirability function-embedded face-centered optimization model. For this, effects of pH (4.5–5.5–6.5, x 1), (2) temperature (25–30–35 °C, x 2), (3) incubation period (24–48–72 h, x 3), and (4) agitation speed (100–150–200 rpm, x 4) on two response variables; (1) ee (%) and (2) cr (%) were tested. Next, desirability function-embedded face-centered optimization model revealed that a pH of 6.43, a temperature of 26.04 °C, an incubation period of 52.41 h, and an agitation speed of 150 rpm were the optimum levels and the estimated ee and cr responses were 99.31% and 98.16%, respectively. Importantly, the actual experimental ee and cr responses were similar to the estimated values indicating the capability of the offered desirability function-embedded face-centered optimization model when using the optimum cultural conditions.

  AtıfScopus1·WoS1·OpenAlex3

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• MakaleYalnız künye2022Scopus SJRQ3/r/bayburt/12016
  Optimization of asymmetric reduction conditions of 1-(benzo [d] [1,3] dioxol-5-yl) ethanone by Lactobacillus fermentum P1 using D-optimal experimental design-based model

  Özdemir, Akın; Dertli, Enes; Şahin, Engin

  The biocatalytic asymmetric reduction of prochiral ketones is a significant transformation in organic chemistry as chiral carbinols are biologically active molecules and may be used as precursors of many drugs. In this study, the bioreduction of 1-(benzo [d] [1,3] dioxol-5-yl) ethanone for the production of enantiomerically pure (S)-1-(1,3-benzodioxal-5-yl) ethanol was investigated using freeze-dried whole-cell of Lactobacillus fermentum P1 and the reduction conditions was optimized with a D-optimal experimental design-based optimization methodology. This is the first study using this optimization methodology in a biocatalytic asymmetric reduction. Using D-optimal experimental design-based optimization, optimum reaction conditions were predicted as pH 6.20, temperature 30 °C, incubation time 30 h, and agitation speed 193 rpm. For these operating conditions, it was estimated that the product could be obtained with 94% enantiomeric excess (ee) and 95% conversion rate (cr). Besides, the actual ee and cr were found to be 99% tested under optimized reaction conditions. These findings demonstrated that L. fermentum P1 as an effective biocatalyst to obtain (S)-1-(1,3-benzodioxal-5-yl) ethanol and with the D-optimal experimental design-based optimization, this product could be obtained with the 99% ee and 99% cr. Finally, the proposed mathematical optimization technique showed the applicability of the obtained results for asymmetric reduction reactions.

  AtıfScopus6·WoS6·OpenAlex7

  İncele
• MakaleYalnız künye2021Scopus SJRQ3/r/bayburt/13465
  Synthesis of silver nanoparticles prepared with a dextran-type exopolysaccharide from Weissella cibaria MED17 with antimicrobial functions

  İspirli, Hümeyra; Sagdic, Osman; Dertli, Enes

  Microbial polysaccharides can find distinct applications as stabilizer agents including synthesis of nanoparticles. In this study, a dextran-type exopolysaccharide (EPS) was used as the stabilizer agent for the green synthesis of silver nanoparticles (AgNPs-Dex) with antimicrobial characteristics. UV–vis spectroscopy analysis was used to test the formation of AgNPs-Dex. The uniform morphology at around 10 nm size was observed for AgNPs-Dex by TEM analysis and importantly EDX analysis demonstrated the embedment of Ag+ ions within dextran as the stabilizer agent. XRD analysis confirmed the crystalline nature of AgNPs-Dex and FTIR analysis demonstrated the interactions of dextran functional groups with silver. DSC and TGA analysis showed the alteration in the thermal stability of AgNPs-Dex compared to the stabilizer dextran. The antibacterial and antifungal activities of AgNPs-Dex were determined against food originated pathogenic bacteria and fungi and important inhibition levels were observed at 1 mg ml−1 concentration of AgNPs-Dex and this activity was observed to be concentration dependent.

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  AtıfScopus17·WoS13·OpenAlex15

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• MakaleAçık Erişim2021Scopus SJRQ3/r/bayburt/12176
  Synthesis of alternan-stabilized zinc nanoparticles: morphological, thermal, antioxidant and antimicrobial characterization

  Yücel, Nur; İspirli, Hümeyra; Mercan, Emin; Erdoğan, Ümmügülsüm; Dertli, Enes

  This study aimed to synthesize zinc nanoparticles with antimicrobial and antioxidant activities using alternan (ZnNPs-Alt) produced by Lactobacillus reuteri E81 as the stabilizing agent. For the characterization of the ZnNPs-Alt, UV–vis spectroscopy, SEM, TEM and EDX analysis, XRD, FTIR and DSC analysis were applied. The functional role of ZnNPs-Alt was tested by determination of their antioxidant activities by DPPH and CUPRAC methodologies and their antibacterial and antifungal activities. Results of this study demonstrated that alternan was utilized as a successful stabilizer to produce crystalline, thermally stabile ZnNPs-Alt with a particle size of ∼ 100 nm. Importantly, strong antioxidant and antimicrobial activities were observed for ZnNPs-Alt in a concentration dependent manner. These findings confirmed the role of alternan as a stabilizing agent for the production of ZnNPs-Alt with functional roles.

  AtıfScopus6·WoS6·OpenAlex8

  İncele
• MakaleAçık Erişim2020Scopus SJRQ3/r/bayburt/11983
  Determining the optimum model parameters for oligosaccharide production efficiency using response surface integrated particle swarm optimization method: an experimental validation study

  Şensoy, Abdullah Tahir; İspirli, Hümeyra; Dertli, Enes

  Glucansucrases (GTFs) catalyzes the synthesis of α-glucans from sucrose and oligosaccharides in the presence of an acceptor sugar by transferring glucosyl units to the acceptor molecule with different linkages. The acceptor reactions can be affected by several parameters and this study aimed to determine the optimal reaction parameters for the production of glucansucrase-based oligosaccharides using sucrose and maltose as the donor and acceptor sugars, respectively via a hybrid technique of Response Surface Method (RSM) and Particle Swarm Optimization (PSO). The experimental design was performed using Central Composite Design and the tested parameters were enzyme concentration, acceptor:donor ratio and the reaction period. The optimization studies showed that enzyme concentration was the most effective parameter for the final oligosaccharides yields. The optimal values of the significant parameters determined for enzyme concentration and acceptor:donor ratio were 3.45 U and 0.62, respectively. Even the response surface plots for input parameters verified the PSO results, an experimental validation study was performed for the reverification. The experimental verification results obtained were also consistent with the PSO results. These findings will help our understanding in the role of different parameters for the production of oligosaccharides in the acceptor reactions of GTFs.

  AtıfScopus6·WoS6·OpenAlex6

  İncele
• MakaleYalnız künye2019Scopus SJRQ3/r/bayburt/13752
  Response surface methodology as optimization strategy for asymmetric bioreduction of acetophenone using whole cell of Lactobacillus senmaizukei

  Çolak, Nida Sezin; Şahin, Engin; Dertli, Enes; Yilmaz, Mustafa Tahsin; Taylan, Osman

  Whole cell applications are one of the main methodologies for the bioreduction of prochiral ketones to obtain enantiomerically rich chiral secondary alcohols which are mainly affected by the culture parameters of the whole cell. In this study, whole cell of Lactobacillus senmaizukei as a safe Lactic Acid Bacteria (LAB) was used for the reduction of acetophenone and Response Surface Methodology (RSM) application was used to optimize the culture parameters in terms of temperature, pH, incubation time, and agitation level to obtain the highest enantiomeric excess (ee) and conversion rate. The predicted optimum conditions for the bioreduction with whole cell Lactobacillus senmaizukei were found to be pH of 5.25, temperature of 25 °C, incubation time of 72 hr, and agitation level of 100 rpm. Importantly, the efficiency of the reduction of the acetophenone was significantly affected by the linear and quadratic effects of culture parameters. These findings are important to show the role of culture parameters for the bioreduction reactions and also the efficiency of the RSM technique to optimize these parameters.

  AtıfScopus10·WoS10·OpenAlex11

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