Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleYalnız künye2024Scopus SJRQ1Effective biocatalytic synthesis of enentiopure (R)-1,2-diphenylethanol as a pharmaceutical precursor using whole-cell biocatalyst
Çakmak, Fadile; Özdemir, Akın; Dertli, Enes; Şahin, Engin
Optically active alcohols are crucial precursors. 1,2-Diarylethanols and their analogues constitute a significant group of substances of biological significance. The biocatalytic synthesis of (R)-1,2-diphenylethanol ((R)-2), which can be utilized as a precursor to important drugs, is still not at the desired level in terms of substrate amount and production process. This study asymmetrically reduced 1,2-diphenylethanone (1) using the Lactobacillus paracasei BD87E6 biocatalyst and a novel orthogonal quadratic design-embedded optimization approach. The following reaction optimization conditions were determined using the suggested optimization technique: pH = 6, temperature = 31 °C, incubation period = 48 h, and agitation speed=134 rpm. In addition, the reaction conversion was estimated to be 99.38 %, and the product's enantiomeric excess (ee) was estimated to be 99.12 %. Further, (R)-2 was produced with >99 % ee, >99 % conversion, and 98 % yield in the experimental investigation under the established optimum conditions. This study is the first attempt to reduce substrate 1 to (R) or (S)-2 using a mathematical optimization method in the presence of a biocatalyst. Furthermore, on a high-gram scale, 1 (15.70 g) was entirely transformed into (R)-2 (15.54 g, 98 % isolated yield). Notably, this study is also the first to perform the gram-scale production of (R)-2 using a novel optimization approach and a biocatalyst. Finally, the innovative and novel orthogonal quadratic design-embedded optimization technique has been demonstrated as an efficient, cost-effective, and environmentally friendly biocatalytic procedure for synthesizing (R)-2.
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İncele - MakaleAçık Erişim2023Geleneksel yollarla üretilmiş turşu örneklerinden laktik asit bakterilerinin izolasyonu, moleküler yöntemler kullanılarak tanımlanması ve bazı fonksiyonel özelliklerinin belirlenmesi
Dertli, Enes; Ispırlı, Hümeyra
Bu çalışmada ülkemizin farklı illerinden toplanmış 17 adet geleneksel turşu örneğinden Laktik Asit Bakterileri (LAB) izole edilip tanımlanmış ve izolatların fonksiyonel nitelikleri karakterize edilmiştir. Genotipik ayrıştırma sonucunda 9 farklı türe ait 21 suş tespit edilmiştir. Takiben bu 21 suşun potansiyel probiyotik değerlendirmeleri safra tuzlarına direnç ve düşük pH’da gelişim açısından test edilmiş ve Lactiplantibacillus plantarum ve Levilactobacillus brevis suşlarının yüksek canlılık gösterdiği tespit edilmiştir. İzolatlarının antibiyotik dirençlerinin ise oldukça düşük seviyede olduğu gözlenmiştir. Önemli olarak antifungal aktivite açısından suş spesifik etki gözlenirken, antibakteriyel aktivite noktasında oldukça güçlü aktivite sergilemişlerdir. Son olarak turşu izolatlarının GABA üretim potansiyelleri açığa çıkarılmış ve Levilactobacillus brevis VB13 suşunun 0.628±0.11 mg/mL GABA üretebildiği gösterilmiştir. Elde ettiğimiz sonuçlar turşuda bulunan LAB çeşitliliğini ve bu suşların fonksiyonel etki potansiyelini göstermesi bakımından önem arz etmektedir.
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İncele - MakaleAçık Erişim2023Scopus SJRQ2Characterisation of dextran AP-27 produced by bee pollen isolate Lactobacillus kunkeei AP-27
Yilmaz, Mustafa T.; İspirli, Hümeyra; Alidrisi, Hassan; Taylan, Osman; Dertli, Enes
An exopolysaccharide (EPS) produced by bee pollen isolate Lactobacillus kunkeei AP-27 was characterised in this study. EPS monomeric composition of strain AP-27 was characterised by High-performance liquid chromatography (HPLC) analysis and glucose was the only sugar in the EPS repeating unit. Structural analysis of glucan AP27 by 1H and 13C Nuclear magnetic resonance (NMR) analysis demonstrated that this glucan was a dextran ((1→6)-linked α-D-glucose units as the main body) consisting very low level of (1 → 4)-linked α-D-glucose units (∼ 0.5 %). Dextran AP-27 had a degradation temperature of 308 °C that revealed its superior thermal strength identified by Thermogravimetric (TGA) and Differential scanning calorimetry (DSC) analysis. The molecular weight of dextran AP-27 was determined to be 25 kDa by Gel Permeation Chromatography (GPC) analysis. Crystallographic properties of dextran AP-27 was determined by X-ray diffraction (XRD) analysis that divulged its amorphous feature. Scanning Electron Microscopy (SEM) analysis was applied for microstructural characterisation of dextran AP-27 which revealed its regular sphere like characteristics. These findings suggest that Lactic Acid Bacteria (LAB) strains from different environments such as bee products can be the source for distinct EPS producer strains.
AtıfScopus9WoS8OpenAlex7İncele - MakaleAçık Erişim2023Scopus SJRQ3Isolation 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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İncele - MakaleAçık Erişim2023Scopus SJRQ2Characterization of Bee Bread Produced with Defined Starter Cultures Mimicking the Natural Fermentation Process
Poyraz, Fatmanur; Yalmanci, Dilara; İspirli, Hümeyra; Dertli, Enes
Bee bread is a product with unique properties for humans and bees that is produced through the fermentation of pollen in the honeycomb, mainly caused by lactic acid bacteria (LAB) and yeast strains present in the environment. It is a rich source of nutrients such as proteins, polyphenols and vitamins. Despite the potential nutritional value of bee bread, it is consumed at low levels, as harvesting bee bread from the hives is costly and difficult. This study aimed to produce a standard bee bread by using different strains of the fructophilic lactic acid bacteria (FLAB) Lactobacillus kunkeei and the yeasts Starmeralla magnolia MP-2 and Zygosaccharomyces siamensis MP-14, previously isolated from bee products. In this context, bee bread was produced from pollen by solid-state fermentation using selected FLAB and yeast species, which were then compared with spontaneously developed and commercially available bee bread in terms of microbial stability, physicochemical properties, total phenolic component amounts, in vitro digestibility and amino acid profiles. As a result, it was determined that bee bread made from bee pollen fermented with starter cultures showed improved characteristics than commercial bee bread and was more advantageous in terms of absorption as well as production processes.
AtıfScopus19WoS17OpenAlex18İncele - MakaleAçık Erişim2023Scopus SJRQ3Optimization 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.
AtıfScopus1WoS1OpenAlex3İncele - MakaleAçık Erişim2023Scopus SJRQ1Structural characterization of potato starch modified by a 4,6-α-glucanotransferase B from Lactobacillus reuteri E81
Hassanein, Wael S.; İspirli, Hümeyra; Dertli, Enes; Yilmaz, Mustafa Tahsin
The recent reports have revealed that increase in amount of α-1,6 linkages by modification of potato starch with enzyme (glycosyltransferases) treatment gains slowly digestible properties to the starch; however, the formation of new α-1,6-glycosidic linkages diminish the thermal resistance of the starch granules. In this study, a putative GtfB-E81, (a 4,6-α-glucanotransferase-4,6-αGT) from L. reuteri E81 was firstly used to produce a short length of α-1,6 linkages. NMR results revealed that external short chains mostly comprised of 1–6 glucosyl units were newly produced in potato starch, and the α-1,6 linkage ratio was significantly increased from 2.9 % to 36.8 %, suggesting that this novel GtfB-E81 might have potentially an efficient transferase activity. In our study, native and GtfB-E81 modified starches showed fundamental similarities with respect to their molecular properties and treatment of native potato starch with GtfB-E81 did not remarkably change thermal stability of the potato starch, which seems to be very prominent for the food industry given the significantly decreased thermal stability results obtained for the enzyme modified starches reported in the literature. Therefore, the results of this study should open up emerging perspectives for regulating slowly digestible characteristics of potato starch in future studies without a significant change in the molecular, thermal, and crystallographic properties.
AtıfScopus14WoS14OpenAlex18İncele - MakaleYalnız künye2023Scopus SJRQ1Utilisation of an active branching sucrase from Lactobacillus kunkeei AP-37 to produce techno-functional poly-oligosaccharides
İspirli, Hümeyra; Korkmaz, Kader; Arioglu-Tuncil, Seda; Bozkurt, Fatih; Sağdıç, Osman; Tunçil, Yunus Emre; Narbad, Arjan; Dertli, Enes
Glucansucrase AP-37 was extracted from the culture supernatant of Lactobacillus kunkeei AP-37 and characteristics of the glucan produced by the active glucansucrase in terms of structural and functional roles were determined in this study. A molecular weight around 300 kDa was observed for glucansucrase AP-37 and its acceptor reactions with maltose, melibiose and mannose were also conducted to unveil the prebiotic potential of the poly-oligosaccharides formed via these reactions. The core structure of glucan AP-37 was determined by 1H and 13C NMR and GC/MS analysis which revealed that glucan AP-37 was a highly branched dextran composing of high levels of (1 → 3)-linked α-D-glucose units with low levels of (1 → 2)-linked α-D-glucose units. The structural features of the glucan formed, demonstrated that glucansucrase AP-37 was an α-(1 → 3) branching sucrase. Dextran AP-37 was further characterised by FTIR analysis and XRD analysis demonstrated its amorphous nature. A fibrous compact morphology was observed for dextran AP-37 with SEM analysis whereas TGA and DSC analysis revealed its high stability as no degradation was observed up to 312 °C. Finally, the prebiotic potential of the dextran AP-37 and the gluco-oligosaccharides produced with the acceptor reaction of α-(1 → 3) branching sucrase AP-37 were determined and promising results were found for the gluco-oligosaccharides to act as prebiotics.
AtıfScopus13WoS12OpenAlex13İncele - MakaleAçık Erişim2023Scopus SJRQ3The characterization of the non-starter lactic acid bacteria and yeast microbiota and the chemical and aromatic properties of traditionally produced Turkish White Cheese
Macit, Emine; Yücel, Nur; Dertli, Enes
Turkish White Cheese is a brined (or pickled) cheese with a salty, acidic flavor and a soft or semi-hard texture. It is the most produced and consumed type of cheese in Turkey. The purpose of this study was to determine the non-starter lactic acid bacteria and yeast microbiota of traditionally produced Turkish White Cheese and analyze the chemical properties and the aroma profile of the cheese. The results of the study identified 27 distinct strains belonging to 14 the non-starter lactic acid bacteria species and 49 different strains belonging to 11 yeast species. Lactobacillus plantarum was found to be the dominant species among the lactic acid bacteria, while Candida zeylanoides was the dominant yeast species in the White Cheese samples. In addition, Kluyveromyces lactis and Debaryomyces hansenii were prominent yeast species in cheese samples. Turkish White Cheese samples had different aromatic properties. The study is highly significant as it anaylzed both non-starter lactic acid bacteria and yeast microbiota of traditionally produced Turkish White Cheese through molecular methods. It also determined and analyzed a number of chemical and aromatic properties of White Cheese.
AtıfScopus6WoS6OpenAlex5İncele - MakaleAçık Erişim2022Scopus SJRQ3Optimization of lactose derivative hetero-oligosaccharides production using whey as the acceptor molecule by an active glucansucrase
Kabli, Mohammad; İspirli, Hümeyra; Balubaid, Mohammed; Taylan, Osman; Yılmaz, Mustafa Tahsin; Dertli, Enes
Glucansucrases are capable of synthesis of distinct oligosaccharides using different acceptor molecules and in this study lactose derivative hetero-oligosaccharides were shown to be produced by an active glucansucrase in its acceptor reaction with sucrose and whey as the donor-acceptor molecules, respectively. Following the monitoring of the reaction products by TLC analysis, the effects of reaction parameters in terms of enzyme concentration, sucrose/whey ratio and reaction temperature on final oligosaccharide yields (OY) were optimized by Response Surface Methodology (RSM). Results indicated that increment of enzyme concentration and reaction temperature decreased the OY in a particular reaction time whereas the OY increased with the increment of sucrose/whey ratio in the acceptor reactions of glucansucrase E81 with whey as the acceptor molecule. A low level of glucansucrase E81 concentration was sufficient to obtain the highest OY in the tested conditions. These findings demonstrated the importance of the optimisation of the reaction parameters for the acceptor reactions of the glucansucrases.
AtıfScopus2WoS4OpenAlex6İncele - MakaleAçık Erişim2022Scopus SJRQ1Optimization of Asymmetric Bioreduction Conditions of 2-methyl-1-phenylpropan-1-one by Lactobacillus fermentum BY35 Using I-Optimal Design-Based Model
Aksuoğlu, Selmani; Özdemir, Akın; Serencam, Hüseyin; Dertli, Enes; Şahin, Engin
The bioreduction of prochiral ketones offers efficient access to chiral secondary alcohols, which are potentially beneficial precursors for producing many biologically active compounds and natural products. This bioreduction process can be affected by different parameters when whole-cell of biocatalysts such as Lactic Acid Bacteria strains are applied. In this context, this paper proposed an I-optimal design-based model to optimize culture parameters such as temperature, pH, incubation period, and agitation speed for asymmetric bioreduction of 2-methyl-1-phenylpropan-1-one (1) with Lactobacillus fermentum BY35 as a biocatalyst while achieving the highest conversion rate (cr) and enantiomeric excess (ee). The optimum settings of the four culture parameters and the cr and ee values were found using the proposed optimization model as follows: pH = 6.5, temperature = 25 °C, incubation period = 38.5 h, agitation speed = 200 rpm, the ee value = 98.78%, and the cr value = 98.92%. After the validation of the process, the cr and ee values were found to be > 99% and > 99%, respectively, while using the optimum operating conditions from the optimization model. Thus, the results of the optimization model are consistent with the results of the validation experiment. It is also noted that this paper is the first to optimize culture parameters using the proposed I-optimal design-based model for an asymmetric reduction.
AtıfScopus3WoS3OpenAlex3İncele - MakaleAçık Erişim2022Scopus SJRQ1Optimization of Biocatalytic Production of Enantiopure (S)-1-(4-Methoxyphenyl) Ethanol with Lactobacillus senmaizuke Using the Box–Behnken Design-Based Model
Kavi, Mervenur; Özdemir, Akın; Dertli, Enes; Şahin, Engin
Enantiomerically pure (S)-1-(4-methoxyphenyl) ethanol is a significant molecule for the production of various drug intermediates. (S)-1-(4-methoxyphenyl) ethanol was synthesized from 4-methoxyacetophenone using Lactobacillus senmaizuke as a biocatalyst. In addition, optimization of experimental conditions is important to analyze the role of culture parameters for catalytic bioreduction reactions. For this particular purpose, the experimental conditions of pH, incubation period, temperature, and agitation speed were investigated with the Box–Behnken experimental design-based proposed optimization model. (S)-1-(4-methoxyphenyl) ethanol, which can be used for the synthesis of antihistamines, including diphenhydramine hydrochloride and loratadine cycloalkyl [b] indoles that have the treatment function for an allergic response, was obtained in > 99% conversion, > 99% enantiomeric excess and 96% yield with whole cells of L. senmaizukei at this optimization conditions: pH = 5.80, the temperature = 29 °C, incubation period = 50 h, and agitation speed = 155 rpm. The bioreduction of 4-methoxyacetophenone efficiency was importantly affected by the quadratic and linear effects of experimental design parameters. Besides, the results demonstrate the importance of design parameters for catalytic bioreduction reactions. It is also concluded that the results show the effectiveness of the Box–Behnken experimental design-based proposed model to obtain optimum operating conditions of design parameters for catalytic bioreduction reactions.
AtıfScopus4WoS4OpenAlex4İncele - MakaleYalnız künye2022Scopus SJRQ1Bioactive and technological properties of an α-D-glucan synthesized by Weissella cibaria PDER21
Yilmaz, Mustafa Tahsin; Ispirli, Humeyra; Taylan, Osman; Alamoudi, Mohammed; Dertli, Enes
A slimy-mucinous-type colony of EPS-producing Weissella cibaria PDER21 was isolated and identified. The monomer composition was glucose, showing that the EPS is a glucan type homopolysaccharide, The core structure of (1 → 6)-linked α-D-glucose units including (1 → 3)-linked α-D-glucose branches at a ratio of 93.4/6.6 was revealed by 1H and 13C NMR spectra and confirmed by FTIR analysis. The glucan showed a superior thermal stability with almost no degradation in structure up to 300 °C. XRD analysis revealed the amorphous structure while SEM analysis confirmed the layer-like morphology. The glucan had an antioxidant activity (89.5%), water-holding capacity (103.7%) and water solubility index (80.7%) values, suggesting that the glucan had a strong level of antioxidant properties; good water binding capacity and excellent solubility. The glucan PDER21 is a polysaccharide possessing a good combination of technical and functional attributes, suggesting a great deal of potential for use in the food industry.
AtıfScopus42WoS41OpenAlex40İncele - MakaleAçık Erişim2022Scopus SJRQ4Isolation of Distinct Lactobacillaceae spp. with Functional Characteristics from Traditional Sourdough Samples; [Geleneksel Ekşi Hamur Örneklerinden Fonksiyonel Özelliklere Sahip Farklı Lactobacillaceae spp. İzolasyonu]
İspirli, Hümeyra; Dertli, Enes
Lactic Acid Bacteria (LAB) were isolated from traditional sourdough samples, and functional properties of selected LAB species were determined. Five distinct strains Limosilactobacillus fermentum LR1, Lacticaseibacillus rhamnosus LR2, Levilactobacillus senmaizukei CE37, Lactiplantibacillus plantarum CE48 and Limosilactobacillus reuteri KD44A were identified following the genotypic discrimination of hundred isolates. Presence of bacteriocin genes in identified species was determined by PCR, and sourdough isolates have been shown to carry bacteriocin genes although they vary according to species. Exopolysaccharide (EPS) production tests showed that the amount of EPS production varies in different media and different incubation conditions. Antimicrobial effects of 5 different LAB species were determined against Bacillus cereus BC 6830, which cause rop problems, and other pathogen species and also molds isolated from bread. Amylolytic activities of isolates, which are important in terms of technological roles, were determined genotypically and phenotypically. Finally, the phytase and phosphatase activities of these species were studied. This study was aimed to unveil the functional sourdough LAB species to be used for industrial purposes.
AtıfScopus4OpenAlex3İncele - MakaleYalnız künye2022Scopus SJRQ1Characterisation and functional roles of a highly branched dextran produced by a bee pollen isolate Leuconostoc mesenteroides BI-20
Yilmaz, Mustafa Tahsin; İspirli, Hümeyra; Taylan, Osman; Taşdemir, Volkan; Sagdic, Osman; Dertli, Enes
Lactic Acid Bacteria (LAB) from different niches can be responsible for the production of distinct exopolysaccharides (EPS) that might possess important structural and technological features. In this respect, the aim of this study was to isolate an EPS producer LAB strain from bee pollen environment. Leuconostoc mesenteroides BI-20 with a slimy-mucoid colony morphology was identified from bee pollen and the structural, technological and functional characteristics of EPS produced by this strain were determined. EPS BI-20 was a highly branched dextran containing 20% (1 → 3)-linked α-D-glucose branches determined by 1H and 13C NMR analysis. The presence of (1 → 6)/(1 → 3)-linked α-D-glucose linkages in dextran BI-20 was also confirmed by FTIR analysis. Dextran BI-20, with a molecular weight of 1 × 108 Da, possessed strong thermal properties, amorphous nature and highly branched and fibrous microstructural characteristics determined by DSC, TGA, XRD and SEM analysis, respectively. In terms of functional roles, dextran BI-20 demonstrated strong antioxidant capacity detected by ABTS and CUPRAC tests. Finally, no digestion was observed in dextran BI-20 under simulated gastric conditions. Results of this study unveiled techno-functional characteristics of dextran BI-20 produced by a bee pollen isolate LAB strain.
AtıfScopus39WoS36OpenAlex39İncele - MakaleYalnız künye2022Scopus SJRQ2The effect of flours of different immature cereal grains on sourdough and sourdough bread: Microbiological, rheological, textural and sugar profiles
Alkay, Zühal; Yılmaz, Mustafa Tahsin; Can, Aslı Muslu; İspirli, Hümeyra; Dertli, Enes
In this study, the utilization of LAB (Lactiplantibacillus plantarum, Levilactobacillus brevis, Furfurilactobacillus rossiae, Weissella cibaria) cultures with selected flours of different immature cereal grains (wheat, barley, oat and rye) on sourdough and sourdough bread was investigated. In total, 16 different sourdough breads were produced and microbiological, pH, TTA and rheological properties of sourdoughs at 0, 8 and 24 h were determined. At the beginning of the fermentation, while sourdoughs showed elasticity, they showed viscoelastic properties after 24 h of fermentation. The sugar profile of cereal grains at the stage of milk formation and the sugar groups presented in EPSs isolated from sourdoughs were revealed by HPLC analysis. The sugar groups in sourdoughs were glucose, xylose and arabinose, while the sugars in the immature cereal grains were glucose, fructose and mannose. The highest EPS production level (1882.69 ± 8.16) was observed in immature barley flour and Lpb. plantarum containing sourdough and all sourdoughs were found to contain glucan type EPSs. It was observed that the amount of EPS produced by the related species differed significantly under different grain conditions. Besides, it was observed that the sourdough breads produced were harder than the control bread. Novelty Impact Statement: Wheat, barley, oat and rye immature grains and four distinct LAB strains were used during sourdough fermentation. Immature grain type and LAB strain used were determinants for in situ exopolysaccharide (EPS) production. Viscoelastic properties of sourdough and textural properties of sourdough bread were affected by grains and LAB strain utilized.
AtıfScopus5WoS2İncele - MakaleYalnız künye2022Scopus SJRQ1Structural and bioactive characteristics of a dextran produced by Lactobacillus kunkeei AK1
Yilmaz, Mustafa Tahsin; İspirli, Hümeyra; Taylan, Osman; Bilgrami, Anwar L.; Dertli, Enes
In this study, structural and techno-functional characteristics of an exopolysaccharide (EPS) produced by Lactobacillus kunkeei AK1 were determined. High-performance liquid chromatography (HPLC) analysis demonstrated that EPS AK1 was composed of only glucose units. 1H and 13C Nuclear magnetic resonance (NMR) analysis revealed that EPS AK1 was a dextran type EPS containing 4.78% (1 → 4)-linked α-D-glucose branches. The molecular weight of EPS AK1 was determined to be 45 kDa by Gel Permeation Chromatography (GPC) analysis. A high level of thermal stability up to 280 °C was determined for dextran AK1 detected by Differential scanning calorimetry (DSC) and Thermogravimetric analysis (TGA). Dextran AK1 appeared as regular spheres with compact morphology and as irregular particles in the solution with no clear cross-linking between the chains of the polysaccharide observed by Scanning electron microscopy (SEM) and Atomic force microscopy (AFM) analysis, respectively. X-ray diffraction analysis (XRD) analysis demonstrated that dextran AK1 had a crystalline structure. A relatively strong antioxidant activity was observed for dextran AK1 determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging and cupric reducing antioxidant capacity (CUPRAC) tests. Finally, only a digestion ratio of 3.1% was observed for dextran AK1 following the in vitro simulated gastric digestion test.
AtıfScopus43WoS39OpenAlex41İncele - MakaleYalnız künye2022Scopus SJRQ3Biocatalytic asymmetric synthesis of (S)-1-indanol using Lactobacillus paracasei BD71
Kalay, Erbay; Dertli, Enes; Şahin, Engin
Enantiopure benzo-fused cyclic alcohols have been used as a building block of a drug for Parkinson’s disease. Biocatalytic reduction of ketones is one of the most promising and significant routes to prepare optically active alcohols. In this study, the reductive capacity of seven lactic acid bacteria (LAB) strains were investigated as whole-cell biocatalyst in the enantioselective reduction of 1-indanone (1). Lactobacillus paracasei BD71 was found to have the best reductive capacity. Effects of different parameters such as pH, incubation time, agitation speed and temperature, on enantiomeric excess (ee) and conversion were investigated in a bioconversion. (S)-1-indanol ((S)-2) could be used as precursor for the synthesis of rasagiline mesylate TVP1012 for the therapy of Parkinson’s illness. It was produced in gram-scale (5.24 g), high yield (93%) and enantiomerically pure form using L. paracasei BD71 whole-cell biocatalysts. Also, to our knowledge, this is the first report on production of (S)-2 using whole-cell catalyst in enantiopure form, excellent yield, conversion and gram scale. This is a cheap, clean and eco-friendly process for production of (S)-2 compared to chemical processes.
AtıfScopus6WoS6OpenAlex6İncele - MakaleYalnız künye2022Scopus SJRQ3Optimization 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.
AtıfScopus6WoS6OpenAlex7İncele - MakaleYalnız künye2022Scopus SJRQ1Comparison of the probiotic characteristics of Lactic Acid Bacteria (LAB) isolated from sourdough and infant feces
Kaya, Yasemin; Erten, Tayyibe; Vurmaz, Melike; İspirli, Hümeyra; Şimşek, Ömer; Dertli, Enes
Probiotics are beneficial microorganisms with certain characteristics such as survival under gastrointestinal conditions, adhesion to intestinal surface and different functions which result in several health benefits to host. With this regards, this study aimed to isolate Lactic Acid Bacteria (LAB) from sourdough and human feces as two different environments and to test their potential probiotic functions. In total nine distinct isolates were assessed with several probiotic functions such as in vitro adhesion to human colon cells, antimicrobial activities and survival under harsh gastrointestinal conditions. In general, distinct strains showed strong antimicrobial activity against the pathogenic and fungal strains tested in this study. Importantly, the adhesion levels to HT29 cells were determined between 0.29 % and 9.54% and Lactobacillus paracasei F7B showed the highest adhesion. All isolates tolerated the bile salt after 24 h and the infant feces isolates showed good survival characteristics at pH 4.
AtıfScopus18WoS15OpenAlex18İncele