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Ağır metallerin değişik termofilik bakterilerdeki akümülasyonu, biyosorpsiyonu ve çevre biyoteknolojisinde kullanımı üzerine çalışmalar
(2017) Özdemir, Sadin; Güven, Kemal
Bu çalışmada Nicolaus B. ve arkadaşları tarafından izole edilen ve tanımlanan termofilik karakterdeki Geobacillus toebii sub sp. decanicus, Bacillus thermantarcticus, Anoxybacillus amylolyticus, ve Geobacillus thermoleovorans sub.sp. stromboliensis bakterilerin farklı metallere (Cd, Co, Cu, Mn, Zn ve Ni) karşı toleranslarını için minimum inhibisyon konsantrasyonları (MIC) katı besiyerinde tespit edildi. Ayrıca, farklı metal (Cd, Co, Cu, Mn, Zn ve Ni) konsantrasyonlarının Geobacillus toebii sub.sp. decanicus, Bacillus thermantarcticus, Anoxybacillus amylolyticus, ve Geobacillus thermoleovorans sub.sp. stromboliensis üremesine etkisi ve bu metallerin akümülasyonu sıvı besiyerinde incelendi. Bu bakterilerin sıvı besiyerinde katı besiyerine göre daha duyarlı oldukları tespit edildi. Çalışılan dört farklı termofilik varyeteleri farklı biyoakümülasyon kapasiteleri göstermiştir ve en yüksek Cd, Cu ve Zn biyoakümülasyon kapasitelerinin sırasıyla; 7196,2; 6862,1ve 36496 µg/g kuru bakteri ağırlığı olarak Geobacillus toebii sub.sp. decanicus ile elde edildiği, en yüksek Co biyoakümülasyon kapasitesinin 620,1 µg/g kuru bakteri ağırlığı olarak Bacillus thermoantarcticus ile elde edildiği, en yüksek Ni biyoakümülasyon kapasitesinin 977,2 µg/g kuru bakteri ağırlığı olarak Geobacillus thermoleovorans sub.sp. stromboliensis ile ve en yüksek Mn biyoakümülasyon kapasitesinin ise 28566 µg/g kuru bakteri ağırlığı olarak Anoxybacillus amylolyticus ile gerçekleştirildiği tespit edildi. Kurutulmuş ölü Bacillus thermantarcticus ve Anoxybacillus amylolyticus tarafından Cd, Co, Cu ve Mn Geobacillus thermoleovorans sub.sp. stromboliensis ve Geobacillus toebii sub.sp. decanicus tarafından Cd, Cu, Mn, Zn ve Ni biyosorpsiyonu üzerine pH (2,0-10,0), sıcaklık (30-80 οC) , başlangıç metal konsantrasyonu (10, 25, 50, 100, 200 and 300 mg/l), biyokütle miktarı (0,25, 0,5, 1,25, 2,5, 5 and 10 g/l), zaman (15, 30, 45, 60, 90, 120 min.) ve çalkalamanın biyosorpsiyon üzerine etkisi çalışıldı. Termofilik bakterilerde tüm metaller için optimum pH değerleri 4,0-6,0 arasında tespit edildi. Termofilik bakterilerde metal uzaklaştırılması için optimum sıcaklık bakterilerin kendi üreme sıcaklıklarına yakın değerde olduğu tespit edildi. Farklı Cd konsantrasyonlarına maruz kalan canlı ve kurutulmuş ölü Geobacillus toebii sub.sp. decanicus’un hücre membranında metal biyosorpsiyonu belirlendi. Ayrıca, Amberlit XAD-4 üzerine tutturulmuş ölü (Kurutulmuş) Geobacillus thermoleovorans sub.sp. stromboliensis’in ağır metal prekonsantrasyonu ve uzaklaştırılması için kullanılmıştır. Cd, Cu, Ni, Mn ve Zn için prekonsantrasyon faktörü 125 olarak tespit edildi. Cd, Cu, Mn ve Zn metalleri için geri kazanım yüzdeleri % 100 olarak, Ni için ise % 97,5 olarak tespit edildi. Anahtar Kelimeler: Termofilik bakteriler, Ağır metal, Minimum İnhibisyon Konsantrasyonu (MIC), biyoakümülasyon, biyosorpsiyon, immobilizasyon, prekonsantrasyon
Bioaccumulation, resistance, and remediation of Mn(II) and Cu(II) and their impacts on antioxidant enzymes of Anoxybacillus flavithermus
(Institute for Ionics, 2023) Özdemir, Sadin; Turkan, Zeynep; Kılınç, Ersin; Altuner, Elif Esra; Şen, Fatih
In this article, the effects of copper (Cu(II)) and manganese (Mn(II)) ions on the superoxide dismutase (SOD) and catalase enzymes (CAT) of the thermophilic Anoxybacillus flavithermus (A. flavithermus) were thoroughly examined. Results from experiments using the minimum inhibitory concentration (MIC) showed that A. flavithermus was less tolerant of ions in the liquid media than in the solid medium. In comparison to the control, the greatest percentage of bacterial growth was determined to be 20.4% including the addition of Mn(II) and 17.6% including the addition of Cu(II). Mn(II) bioaccumulation increases the total weight of the bacteria, while Cu(II) bioaccumulation specifically increases the weight of dry A. flavithermus (MDBW). The ability of A. flavithermus cell membrane to bioaccumulate ions was examined. At various ion concentrations, the CAT and SOD activities were examined. Any possible morphological alteration following the encounter with ions. The findings suggested that A. flavithermus may be used to extract and remove hazardous metals from industrial wastewaters. A. flavithermus is a potential bioindicator of hazardous metal-contaminated waters, according to antioxidative enzyme activity. Additionally, the activities of the antioxidant enzymes CAT and SOD increased with increasing ion concentrations up to 10.0 mg/L over a 48 h period. This indicates a protective response against oxidative stress caused by Cu(II) and Mn(II) ions.
Bioaccumulation, resistance, removal of U(VI) and Th(IV) and their rffects on antioxidant enzymes on thermophilic anoxybacillus flavithermus ST15
(Taylor & Francis, 2021) Acer, Ömer; Kılınç, Ersin; Özdemir, Sadin
In this research, a novel heavy metals resistance thermophilic Anoxybacillus flavithermus ST15 was isolated from a hot spring mud sample in Afyonkarahisar (Omer). 16S rRNA analyzing revealed that strain ST15 was 99.7% similar to Anoxybacillus flavithermus subsp. yunnanensis str. E13. We propose that U(VI) and Th(IV) have an effect on A. flavithermus at the cellular level and that this bacteria can be used as a bioindicator. Therefore, the effects of U(VI) and Th(IV) resistance, removal, and bioaccumulation on the antioxidant enzyme systems of thermophilic A. flavithermus have been thoroughly investigated. SOD and CAT activities were observed to be increased by different concentrations of U(VI) and Th(IV). A scanning electron microscope and fourier transform infrared spectroscopy were used to analyze changes in the surface macrostructure and functionality of A. flavithermus following interaction with U(VI) and Th(IV). The highest bioaccumulation efficiency amounts for U(VI) were 102.36 mg/g dried bacteria at 24 h at 12.5 mg/l concentration and 105.7 mg/g dried bacteria at 36 h at 12.5 mg/l concentration was detected for Th(IV). At the 24th h and 12.5 mg/l, the highest U(VI) and Th(IV) cell membrane bioaccumulation capacities of A. flavithermus were calculated as 307.08 and 289.52 mg metal/g wet membrane, respectively. This is the first research to examine U(VI) and Th(IV) resistance, removal, and bioaccumulation in thermophilic A. flavithermus.
Biosorption of 2,4-d, 2,4-DP, and 2,4-DB from aqueous solution by using thermophilic anoxybacillus flavithermus and analysis by high-performance thin layer chromatography: Equilibrium and kinetic studies
(Wiley, 2012) Özdemir, Sadin; Bekler, Fatma Matpan; Okumuş, Veysi; Dündar, Abdurrahman; Kılınç, Ersin; 0000-0001-8253-9568; 0000-0001-7384-7358; 0000-0002-5505-2700; 0000-0002-7930-1054; 0000-0001-5223-9919
In this study, the potential biosorption characteristics of the thermophilic Anoxybacillus flavithermus (A. flavithermus) was investigated for the removal of the chlorophenoxy acid derivates, namely, 2,4-dichlorophenoxy acetic acid (2,4-D), 2,4-dichlorophenoxy propanoic acid (2,4-DP or dichlorprop), and 2,4-dichlorophenoxy butyric acid (2,4-DB). The experiments were performed for the simultaneous biosorption of the studied pesticides. Optimum biosorption conditions were determined as a function of contact time, pH of the solution, amount of biomass, and initial pesticides concentrations. The concentrations of the pesticides in the remaining solutions were simultaneously analyzed by high performance thin layer chromatography. The optimum parameters were found as pH: 4.0 for biosorption medium, 60 min of contact time, 50 mg of bacteria, and 50 mg L-1 of initial pesticides concentrations. Langmuir and Freundlich models were applied to describe the biosorption isotherm of the pesticides by A. flavithermus as biomass. Biosorption of pesticides on to A. flavithermus showed pseudo first-order rate kinetics at different initial concentration of pesticides and different temperatures. The experimental adsorption data were fitted both the Langmuir and Freundlich adsorption models. Fourier-transform Infrared spectroscopy was used to understand the bonding mechanism of pesticides to biosorbent and surface functionality of the biosorbent The highest pesticide uptake was calculated from Langmuir isotherm and found to be 24.15 mg g-1 for 2,4-D. Among the studied pesticides, 2,4-DP showed difference adsorption behavior. According to in your comments the reason of this that 2,4-DP contain an asymmetric carbon atom, which provide a molecular chirality. (C) 2011 American Institute of Chemical Engineers Environ Prog, 2011
Determination of cytotoxic, anticholinesterase, antioxidant and antimicrobial activities of some wild mushroom species
(Informa Healthcare, 2016) Dündar, Abdurrahman; Okumuş, Veysi; Özdemir, Sadin; Çelik, Kadir Serdar; Boğa, Mehmet; Özçağlı, Eren; 0000-0002-5505-2700
In the performed study of methanol extraction of wild edible mushroom species; Agaricus arvensis, Agaricus campestris, Armillaria mellea, Fomes fomentarius, Coprinus micaceus, Coriolus versicolor and Lactarius deliciosus were examined for screening their cytotoxic, anticholinesterase, antioxidant and antimicrobial capacity. Phenolic acid composition of mushrooms was also analysed. L. deliciosus and F. fomentarius were generally showed the highest activities at antioxidant test systems (metal chelating, superoxide anion radical scavenging, total antioxidant, 2,2-diphenyl-1-picrylhydrazyl radical scavenging and reducing power activity tests). The highest activities at antimicrobial activity displayed by A. arvensis and as 18 ± 0.8 against to Staphylococcus aureus. The best IC50 values of mushroom methanol extracts at anticancer activities on HeLa and NRK-52E were 7.09 and 18.23 mg/mL exhibited by C. micaceus and A. campestris, respectively. The highest butyrylcholinesterase activity exhibited by L. deliciosus. Total amount of phenolic acids were found as 1,224.70 mg/kg at L. deliciosus.
A fungal functionalized magnetized solid phase extractor for preconcentrations of Pb(II), Mn(II), and Co(II) from real samples
(Elsevier Ltd., 2023) Özdemir, Sadin; Yalçın, Mustafa Serkan; Kılınç, Ersin; Soylak, Mustafa
Due to increasing industrialization and overpopulation, the amount of toxic metals is increasing in the environment, including air, soil, water, and food. Solid phase extraction is an efficient and ideal technique to preconcentrate the toxic metals before their measurements by analytical instruments. Russula brevipes was immobilized on γ-Fe2O3 magnetic nanoparticles and employed as a SPE sorbent to preconcentrate the trace level of Pb(II), Mn(II), and Co(II). To investigate the extraction conditions, significant experimental parameters were examined in details. LODs were calculated as 0.022, 0.015, and 0.024 ng mL− 1 for Pb(II), Mn(II), and Co(II), respectively. The biosorption capacities of R. brevipes immobilized γ-Fe2O3 were calculated as 43.1 mg g− 1 for Pb (II), 54.9 mg g− 1 for Mn(II), and 49.7 mg g− 1 for Co(II). Pb(II), Mn(II), and Co(II) in food samples at trace levels were preconcentrated by applying the developed method.
Investigations of Hg(II) and Pb(II) tolerance, removal and bioaccumulation and their effects on antioxidant enzymes on thermophilic Exiguobacterium profundum
(Taylor and Francis Inc., 2020) Akkoyun, Mahire Bayramoğlu; Özdemir, Sadin; Kılınç, Ersin; Birhanli, Emre
Hg(II) and Pb(II) tolerance, removal, bioaccumulation and effects on antioxidant enzymes of thermophilic Exiguobacterium profundum were investigated. The results indicated that Hg(II) was more toxic than Pb(II) to E. profundum. E. profundum was also more tolerant in solid medium than in liquid medium for Pb(II) and Hg(II). The bacterial growth was not significantly influenced at 1.0 and 2.5 mg/L Pb(II) and Hg(II) for 24 h. The highest Hg(II) and Pb(II) bioaccumulation amounts were determined as 37.56 and 54.35 mg metal/dried bacteria, respectively. Bioaccumulation capacities of the cell membrane of E. profundum for Hg(II) and Pb(II) were determined. The different concentrations of Pb(II) and Hg(II) enhanced the SOD and CAT enzymes. In addition, variations of the surface macrostructure and the functionality of E. profundum after the interaction with Hg(II) and Pb(II) were investigated by the scanning electron microscope (SEM) and the Fourier transform infrared spectroscopy (FT-IR), respectively. This investigation obviously showed that thermophilic E. profundum can also be applied for removal and recovery of toxic metals from industrial wastewater. Clearly, a further investigation should be utilized by thermophilic microorganisms. According to antioxidant enyzme activities, E. profundum can be also used as a bioindicator for the detection of toxic metal pollution in natural water samples.
Magnetic solid-phase extraction based on Coriolus versicolor-immobilized ? -Fe2O3 nanoparticles for preconcentration and determination of Al(III) in water
(2019) Yalçın, Mustafa Serkan; Özdemir, Sadin; Soylak, Mustafa; Kılınç, Ersin
A method for preconcentration of Al(III) prior to its determination by inductively coupled plasma-opticalemission spectrometry (ICP-OES) was developed because the sensitivity of ICP-OES is insufficient for trace-level measurement of Al(III). The method is based on the use of Coriolus versicolor-immobilized ? -Fe 2 O3 magnetic nanoparticles as a solid phase sorbent. The best experimental conditions were found as pH 6.0, 2.0 mL/min flow rate, 100 mg amount of C. versicolor on 150 mg of ? -Fe 2 O3 nanoparticles, and 500 mL of sample volume. The Al(III) absorbed on biosorbent was eluted with 5.0 mL of 1.0 mol/L HCl. Limit of detection, limit of quantitation, linear range, correlation coefficient, relative standard deviation, and preconcentration factor were achieved as 0.03 ng/mL, 0.11 ng/mL, 0.2 to 20 ng/mL, 0.9994, 3%, and 100, respectively. Al(III) was preconcentrated in different water and food samples after successful results were achieved in the case of certified reference samples.
Magnetic solid-phase extraction based on Coriolus versicolor-immobilized ?-Fe2O3 nanoparticles for preconcentration and determination of Al(III) in water and food samples
(TUBITAK, 2019) Özdemir, Sadin; Yalcın, Mustafa Serkan; Kılınç, Ersin; Soylak, Mustafa
A method for preconcentration of Al(III) prior to its determination by inductively coupled plasma-optical emission spectrometry (ICP-OES) was developed because the sensitivity of ICP-OES is insufficient for trace-level measurement of Al(III). The method is based on the use of Coriolus versicolor-immobilized γ -Fe 2 O 3 magnetic nanoparticles as a solid phase sorbent. The best experimental conditions were found as pH 6.0, 2.0 mL/min flow rate, 100 mg amount of C. versicolor on 150 mg of γ -Fe 2 O 3 nanoparticles, and 500 mL of sample volume. The Al(III) absorbed on biosorbent was eluted with 5.0 mL of 1.0 mol/L HCl. Limit of detection, limit of quantitation, linear range, correlation coefficient, relative standard deviation, and preconcentration factor were achieved as 0.03 ng/mL, 0.11 ng/mL, 0.2 to 20 ng/mL, 0.9994, 3%, and 100, respectively. Al(III) was preconcentrated in different water and food samples after successful results were achieved in the case of certified reference samples.
Musa textilis (muz) kabuğu kullanarak katı-faz fermantasyon tekniği ile (SSF) Bacillus sp.'de a-amilaz üretimi
(2016) Özdemir, Sadin; Güven, Kemal
Günümüzde, biyoteknolojide enzimlerin kullanımı giderek önem kazanmaktadır. Bu enzimlerden biri olan a-amilaz, önemli biyoteknolojik enzimler arasındadır, a - amilazlar, nişastanın hidrolizi için gıda, deterjan, tekstil, kağıt, bira ve alkol gibi endüstriyel alanlarda kullanılmaktadır. Muz, karpuz ve kavun kabuğu, buğday ve mercimek kepeği ve darı gibi farklı SSF kaynaklan topraktan izole edilen Bacillus sp. tarafından substrat olarak kullanılarak a - amilaz aktivite oranları test edilmiştir. Enzim üretimi açısından en fazla olandan en az olana doğru muz kabuğu > karpuz kabuğu > mercimek kepeği > buğday kepeği > kavun kabuğu > darı olduğu tespit edilmiştir. Muz kabuğu üzerinde en yüksek aktivite görüldüğünden daha sonraki çalışmalarda muz kabuğu substrat olarak kullamldı. SSF metoduyla Bacillus sp. muz kabuğunu substrat olarak kullanarak değişik inkübasyon sürelerinde a - amilaz aktivitesi ölçülmüştür. İnkübasyon süresi 72. saat olarak uygun bulunmuştur. SSF metoduyla Bacillus sp. muz kabuğunu substrat olarak kullanarak % 2'lik karbon kaynağı eldentisinin a - amilaz aktivitesi üzerine etkisine bakılmıştır. En yüksek aktivitenin nişasta en düşük aktivitenin ise glukoz ile olduğu tespit edilmiştir. Sukroz enzim aktivitesini etkilememiştir. Mannoz, galaktoz, arabinoz ve glukoz kontrolden düşük çıkmıştır. SSF metoduyla Bacillus sp. muz kabuğunu substrat olarak kullanarak % 10'luk azot kaynakları elentisinin a - amilaz aktivitesi üzerindeki etkisine bakılmıştır. Amonyum sülfat, bacto casamino acid, bacto liver ve metWonin kontrolden yüksek çıkmıştır. NH4CI ve NH4N03 kontrolden düşük çıkmıştır. Ürede enzim aktivitesi görülmemiştir. En yüksek aktivitenin amonyum sülfat'ta olduğu tespit edilmiştir. NB besiyerinde üretilen bakterinin süpernatantında a-amilaz enziminin bazı özellikleri incelenmiştir. pH 4-11 arasında a - amilaz aktivite tayini yapıldı. Optimum pH 6 olarak belirlendi. 25 °C ile 95 °C arasında a - amilaz aktivite tayini yapıldı. Optimum sıcaklık 60 °C olarak belirlendi. 60 °C'de zamana bağlı enzim stabilite ölçümü için 30 ile 240 dakika arasında a - amilaz aktivite tayini yapıldı. 15-90 dakikaya kadar enzim aktivitesinde bir artış gözlendi.Sonra 90- 240 dakika arasında enzim aktivitesinde bir azalış görüldü. Bununla birlikte 240 dakika sonunda enzim aktivitesinde bir değişmenin olmadığı tespit edildi. NB besi yerinin üst sıvısında, % 2'lik deterjanların (SDS, CHAPS, omo matik) enzim aktivitesi üzerine olan etkisi zamana bağlı olarak 15 ile 90 dakikalık zaman aralığında test edilmiş, inhibisyon etkisi en fazla olandan en aza doğru SDS > Omo Matik > CHAPS şeklinde olduğu tespit edilmiştir.
A novel bio-solid phase extractor for preconcentrations of Hg and Sn in food samples
(Academic Press INC Elsevier Science, 2022) Kılınç, Ersin; Özdemir, Sadin; Poli, Annarita; Niolaus, Barbara; Romano, Ida; Bekmezci, Muhammed; Şen, Fatih
An ecofriendly preconcentration method was developed based on the use of Geobacillus galactosidasius sp. nov immobilized on Amberlite XAD-4 as an adsorbent for the preconcentrations of Hg and Sn. SEM-EDX performed for the investigation of surface functionality and morphology. The detailed investigations of factors such as pH of the solution, flow rate, interfering ions and sample volume have been thanks to the optimization of the preconcentration system. The optimum pHs were found as 5.0-7.0 for Hg and Sn and also the optimum flow rates were determined as 2 mL min(-1) for recovery of Hg and Sn. Under the best experimental conditions, limits of detections (LOD) were found as 0.53 ng mL(-1) for Hg and 0.27 ng mL(-1) for Sn. RSDs were calculated as 8.2% for Hg and 6.9% for Sn. The process was validated to use certified references (fish samples). ICP-OES was used to measure the levels of Hg and Sn in various real meal patterns after the devised technique was used. Concentrations of Hg and Sn were quantitively measured on gluten-free biscuit, flour, rice, Tuna fish, meat, chicken meat, potato, chocolate, coffee, tap water, energy drink and mineral water samples with low RSD. The developed method emerges as an innovative technology that will eliminate the low cost and toxic effect.
A Novel biosorbent for preconcentrations of Co(II) and Hg(II) in real samples
(Nature Research, 2020) Özdemir, Sadin; Kılınç, Ersin; Fatih, Şen
A new biosorbent, composed of Amberlite XAD-4 loaded with Anoxybacillus kestanboliensis, was developed and surface morphologies were investigated by SEM and FT-IR. It was used for solid phase column preconcentrations of Co(II) and Hg(II) before their measurements by ICP-OES. LODs were calculated as 0.04 and 0.06 ng mL-1 for Co(II) and Hg(II) respectively. The maximum biosorption capacities were determined as 24.3 and 27.8 mg g-1 for Co(II) and Hg(II) respectively. Preconcentration factors were achieved for Co(II) and Hg(II) as 80. The method validation was performed by analyzing certified reference materials. The new process was successfully utilized for the preconcentration of these metals in various food samples. It should be highlighted that the sensitivity of ICP-OES was critically improved by applying developed method. Hence, ICP-OES could be an effective alternative for ICP-MS and/or GF-AAS
A novel magnetized bio-solid phase extractor for the preconcentrations of Hg(II), Ni(II) and Zn(II) from foods
(Academic Press Inc., 2024) Yalçın, Mustafa Serkan; Özdemir, Sadin; Kılınç, Ersin; Soylak, Mustafa
Herein, Agaricus augustus, a mushroom, loaded on γ-Fe2O3 magnetic nanoparticles was developed as a biosorbent for the simultaneous preconcentrations of trace levels of Hg(II), Ni(II), and Zn(II)) in tap water, beverages, and some food samples prior to their determination by inductively coupled plasma optical emission spectrometry (ICP-OES). The experimental factors affecting the extraction performance were carefully examined throughout the investigation. The best experimental conditions were determined as pH 4.0, 3 mL/min of sample flow rate, 75 mg of biosorbent, 100 mg of γ-Fe2O3 magnetic nanoparticles, and 500 mL of sample volume. LOD values were determined as 0.016, 0.011, and 0.023 ng/mL, respectively for Hg(II), Ni(II), and Zn(II). The biosorption capacities were determined as 47.2 mg/g for Hg(II), 51.5 mg/g for Ni(II), and 49.0 mg/g for Zn(II). The effectiveness of the recommended method was assessed using certified reference material.
A novel raw starch hydrolyzing thermostable ?-amylase produced by newly isolated bacillus mojavensis SO-10: Purification, characterization and usage in starch industries
(Instituto de Tecnologia do Parana, 2018) Özdemir, Sadin; Fincan, Sema Agüloğlu; Karakaya, Adem; Enez, Barış
The aim of this study is the production, purification, and characterisation of thermostable raw starch hydrolyzing αamylase produced by Bacillus mojavensis SO-10. The maximum production conditions of α-amylase were found at 36th hour, 35 °C and pH 7.0. We utilized three steps to purify the thermostable α-amylase and as a result, 34-fold and 18% yield were obtained. The molecular weight of purified α-amylase was determined as 73 kD. The Km and Vmax rates were detected as 0.010 mM and 3.38 µmol min−1 , respectively. This purified α-amylase exhibited the highest activity at pH 5.0-6.0 and 70 ºC and showed stability over a wide variety of pH and temperature at 4.0–8.0, and 40– 50 ºC, respectively. The thermostable purified α-amylase exhibited stability in the presence of denaturing agents and heavy metal ions. The purified enzyme hydrolyzed the raw starches of corn and wheat grains in the ratio of 36.7% and 39.2% respectively. The end-yields of soluble starch hydrolysis were analyzed by thin-layer chromatography (TLC). In addition, the usage of purified α-amylase in clarification of apple juice and domestic washing detergent industries were evaluated.
Preconcentrations of Cu (II) and Mn (II) by magnetic solid-phase extraction on Bacillus cereus loaded gamma-Fe2O3 nanomaterials
(Academic Press INC Elsevier Science, 2022) Özdemir, Sadin; Türkan, Zeynep; Kılınç, Ersin; Bayat, Ramazan; Soylak, Mustafa; Sen, Fatih
For the simultaneous preconcentrations of Cu(II) and Mn(II), a novel preconcentration technique was developed and described. Bacillus cereus loaded magnetic gamma-Fe2O3 nanoparticles were prepared and used as support materials on solid-phase extraction procedure. Important experimental parameters were investigated in details and pH 6.0, 3 mL min(-1) of flow rate, 5 mL of 1 mol L-1 of HCl as eluent, 200 mg of biomass, and 200 mg of magnetic gamma-Fe2O3 nanoparticles as support material was found as the best conditions. The preconcentrations factor were found to be 80 for Cu (II) and Mn(II). It was confirmed by the results that SPE columns could be used in 32 cycles. The LOD values calculated for Cu (II) and Mn (II) were 0.09 and 0.08 ng mL(-1), respectively. The RSD values found were less than 3.4%. The extraction recoveries were achieved as higher than 98%. The biosorption capacities of Cu (II), and Mn (II) were 26.0 mg g(-1), 30.3 mg g(-1) respectively. The approach devised for analyzing analyte concentrations in food samples proved to be successful.
Preconcentrations of Pb(II), Ni(II) and Zn(II) by solid phase bio-extractor using thermophilic Bacillus subtilis loaded multiwalled carbon nanotube biosorbent
(Elsevier Ltd., 2023) Özdemir, Sadin; Dündar, Abdurrahman; Dizge, Nadir; Kılınç, Ersin; Balakrishnan, Deepanraj; Prasad, Kashi Sai
An alternative biotechnological solid phase bio-extraction (SPE) method was developed. Bacillus subtilis loaded multiwalled carbon nanotube was designed and used as biosorbent for the preconcentrations of Pb(II), Ni(II), and Zn(II). The experimental parameters such as sample flow rate, pH of sample solution, amounts of Bacillus subtilis and multiwalled carbon nanotube, volume of sample solution and reusability of column which affects the analytical characteristics of the SPE method were investigated in details. Surface structures were examined by using FTIR, SEM. The best pH was determined as 5.0 and the percentages recoveries of Zn(II), Ni(II), and Pb(II) were determined as 99.1%, 98.7%, and 96.2%, respectively, at a flow rate of 3 mL/min. In this study, in which the profitable sample volume was determined as 400 mL and the amount of multiwalled carbon nanotube (MWCNT) as 50 mg. It was also observed that the column had a significant potential to preconcentrate Zn(II), Ni(II), and Pb(II) even after 25 reuses. The biosorption capacities for Zn(II), Ni(II) and Pb(II) were calculated as 39.67 mg/g, 45.98 mg/g and 51.34 mg/g respectively. The LOD values were calculated as 0.024 ng/mL for Pb(II), 0.029 ng/mL for Ni(II), and 0.019 ng/mL for Zn(II). The linear range was detected as 0.25–25 ng/mL. The concentrations of Pb(II), Ni(II), and Zn(II) in a variety of real food samples were determined by using developed method after application of certified reference sample.
Preconcentrations of Zn(II) and Hg(II) in environmental and food samples by SPE on B. licheniformis loaded amberlite XAD-4
(Springernature, 2022) Özdemir, Sadin; Kılınç, Ersin; Acer, Ömer; Soylak, Mustafa
In this work, the separations and preconcentrations of Zn(II) and Hg(II) ions on Bacillus lichenifoemis loaded onto Amberlite XAD-4 resin by solid-phase extraction has been performed. The biosorbent was characterized by using FT-IR, SEM, and EDX. pH, sample flow rate, eluent type and concentration, amount of B. licheniformis and XAD-4 resin, sample volume, and possible interfering ions effect were investigated in details as experimental variables in the SPE procedure. Limit of detection values for Zn(II) and Hg(II) were detected as 0.03 and 0.06 ng-mL(-1), respectively. 0.2-15 ng-mL(-1) linear range values were achieved for Zn(II) and Hg(II), respectively. Relative standard deviation values were found to be lower than 5%. For validation of the procedure, the certified standard reference materials (CWW-TM-D, EU-L-2, NCS ZC73O14, NCS ZC73350) were analyzed. The concentrations of Zn(II) and Hg( II) in water and food samples were measured by ICP-OES. Consequently, it can be inferred that the immobilized B. licheniformis microcolumn has ideal selectivity for Zn(II) and Hg(II) biosorption.
The removal of heavy metal pollution from wastewaters using thermophilic B. cereus SO-16 bacteria
(Elsevier Ltd, 2023) Özdemir, Sadin; Türkan, Zeynep; Kılınç, Ersin; Bayat, Ramazan
In this study, bioaccumulation, remediation, tolerance, and effects of manganese ions (Mn(II)) and copper ions (Cu(II)) on antioxidant enzymes of thermophilic Bacillus cereus (B. cereus) SO-16 were investigated in detail. The findings of the study showed that Mn(II) was less toxic than Cu(II) to B. cereus SO-16. Moreover, B. cereus SO-16 was exhibited less tolerance to Mn(II) and Cu(II) ions in the liquid medium compared to the solid medium. The growth of bacteria was expressively effective for Mn(II) and Cu(II) concentrations of 2.5 mg/L at 24th h. The highest Mn(II) and Cu(II) bioaccumulation values after 48 h incubation of thermophilic B. cereus SO-16 were measured as 102.04 (24th h) and 87.96 (36th h) metal/dry bacteria weight. The change in morphology and functionality of B. cereus SO-16 after interaction with Mn(II) and Cu(II) was tested using various methods. The results indicated that B. cereus SO-16, a thermophilic bacterium, can be utilized in industrial wastewaters to recover and remediation of toxic metals.
Synthesis and characterization of a polydioxanone-coated dipeptide-functionalized magnetic ?-Fe2O3 nanoparticles-modified PES membrane and its biological applications
(MDPI, 2022) Demirci, Özlem; Gonca, Serpil; Tolan, Veysel; Özdemir, Sadin; Dizge, Nadir; Kılınç, Ersin
This work is focused on the synthesis of leucyl-glycine-functionalized γ-Fe2O3 magnetic nanoparticles coated by polydioxanone (γ-Fe2O3-CA-Leu-Gly-PDX) as a polyethersulphone (PES) membrane for biotechnological applications. The physicochemical characteristics were investigated by FT-IR, SEM, XRD, a vibrating sample magnetometer (VSM), and ICP-OES. The present investigation also centered on the several biological activities of γ-Fe2O3-CA-Leu-Gly-PDX. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and metal chelating activity was studied for evaluation of its antioxidant activity potential. It exhibited 100% DPPH radical scavenging and 93.33% metal chelating activity. With applicability to antimicrobial photodynamic therapy, DNA cleavage and antimicrobial activity, the cell viability of γ-Fe2O3-CA-Leu-Gly-PDX was investigated in detail. The γ-Fe2O3-CA-Leu-Gly-PDX demonstrated the significant biofilm inhibition activity as being 81.54% and 86.34% for P. aeruginosa and S. aureus, respectively. Moreover, a novel polyethersulphone nanocomposite membrane incorporated with γ-Fe2O3-CA-Leu-Gly-PDX was prepared. The performance of the γ-Fe2O3-CA-Leu-Gly-PDX-blended polyethersulphone (PES) membrane was investigated by measuring the antifouling and E. coli rejection. The nanocomposite membranes demonstrated remarkable antifouling properties in contrast with the pristine PES when BSA (bovine serum albumin) and E. coli were filtrated. A complete rejection was obtained by the composite membrane. After an application of the membrane study, the modified polyethersulphone (PES) membrane blended with γ-Fe2O3-CA-Leu-Gly-PDX removed 100% of the E. coli.

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