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Öğe Analytical Grade Purification of Phycocyanin from Cyanobacteria(Humana Press Inc, 2020) Khazi, Mahammed Ilyas; Demirel, Zeliha; Liaqat, Fakhra; Dalay, Meltem ConkPhycocyanin is a blue-colored pigment-protein complex that exhibits numerous biofunctions such as anti-inflammation, antioxidation, antitumor, neuroprotective effect, and immunological enhancement. Purified phycocyanin has pharmaceutical and nutraceutical applications. In addition, as a nontoxic and non-carcinogenic natural coloring agent, phycocyanin has many applications in the food and cosmetic industries. This chapter describes a protocol for extraction and analytical grade purification of phycocyanin from cyanobacteria. The purification steps include (1) extraction of phycocyanin from biomass, (2) ammonium sulfate precipitation of phycocyanin and dialysis, and (3) purification of phycocyanin by gel filtration and ion-exchange chromatography.Öğe BİYOKÜTLE İÇİN MİKROALG VE SİYANOBAKTERİ’NİN BÜYÜK ÖLÇEKLİ ÜRETİMİ(2018) Demirel, Zeli?Ha; Tok, Rüştü; İlter, Işıl; Akyıl, Saniye; Erdoğan, Ayşegül; Koç, Mehmet; Dalay, Meltem ConkMikroalgler ve siyanobakteriler, binlerce yıldır ilaç, gıda ve su ürünleri yetiştiriciliği endüstrisi için yüksek değerli bileşiklerin doğal bir kaynağı olarak kullanılmaktadır ve büyük ölçekli mikroalg yetiştirilmesi, yarım yüzyılı aşkın bir süredir yapılmaktadır. Yakın zamanda yeni mikroalg ve siyanobakteri türleri tanımlanmış ve çeşitli ürünler için algal biyokütle yetiştiriciliği ticari ölçekli sistemlere geçilmiştir. İlk olarak, steril şişede (2L, 5L ve 10L) laboratuvar koşullarında yetiştirilen Arthrospira (Spirulina) platensis ve Phaeodactylum tricornutum kültürlerinin spesifik büyüme hızları ve klorofil-a analizleri yapılmıştır. Ardından ticari uygulama için büyük ölçekli siyanobakterler ve mikroalg biyokütlesi üretimi için açık ve kapalı sistemler kuruldu. Alg biyokütlesi üretimi için çevresel koşullar altında bir açık karıştırma tankı ve iki farklı tipte kapalı-kültür sistemi veya fotobiyoteraktör (polipropilen torbalar ve plexiglas tüpleri) kullanıldı. Bununla birlikte, P. tricornutum, düşük sıcaklığa karşı iyi direnç göstermiş ve düşük ışık şiddeti koşullarında bile büyüyebilmiştir. Açık havuz sistemlerinin performansı karşılaştırıldığında, entegre sıcaklık düzenlemesine sahip dış mekan sistemlerinin, daha iyi iklim koşullarına sahip bölgelerdeki açık havuzlarda yetiştirilen kültürlere benzer bir biyokütle üretimi elde edildiği gösterilmiştir. Ülkemizde yetiştirilen mikroalg ve siyanobakterilerin biyokütle verimliliğinin arttırması, ileri teknikle tasarlanan ve düşük maliyetli teknolojilerle geliştirilen fotobiyoreaktör ile sağlanabilir.Öğe Biyokütle İçin Mikroalg ve Siyanobakteri’nin Büyük Ölçekli Üretimi(2018) Demirel, Zeli?Ha; Tok, Rüştü; İlter, Işıl; Akyıl, Saniye; Erdoğan, Ayşegül; Koç, Mehmet; Dalay, Meltem ConkMikroalgler ve siyanobakteriler, binlerce yıldır ilaç, gıda ve su ürünleri yetiştiriciliği endüstrisi için yüksek değerli bileşiklerin doğal bir kaynağı olarak kullanılmaktadır ve büyük ölçekli mikroalg yetiştirilmesi, yarım yüzyılı aşkın bir süredir yapılmaktadır. Yakın zamanda yeni mikroalg ve siyanobakteri türleri tanımlanmış ve çeşitli ürünler için algal biyokütle yetiştiriciliği ticari ölçekli sistemlere geçilmiştir. İlk olarak, steril şişede (2L, 5L ve 10L) laboratuvar koşullarında yetiştirilen Arthrospira (Spirulina) platensis ve Phaeodactylum tricornutum kültürlerinin spesifik büyüme hızları ve klorofil-a analizleri yapılmıştır. Ardından ticari uygulama için büyük ölçekli siyanobakterler ve mikroalg biyokütlesi üretimi için açık ve kapalı sistemler kuruldu. Alg biyokütlesi üretimi için çevresel koşullar altında bir açık karıştırma tankı ve iki farklı tipte kapalı-kültür sistemi veya fotobiyoteraktör (polipropilen torbalar ve plexiglas tüpleri) kullanıldı. Bununla birlikte, P. tricornutum, düşük sıcaklığa karşı iyi direnç göstermiş ve düşük ışık şiddeti koşullarında bile büyüyebilmiştir. Açık havuz sistemlerinin performansı karşılaştırıldığında, entegre sıcaklık düzenlemesine sahip dış mekan sistemlerinin, daha iyi iklim koşullarına sahip bölgelerdeki açık havuzlarda yetiştirilen kültürlere benzer bir biyokütle üretimi elde edildiği gösterilmiştir. Ülkemizde yetiştirilen mikroalg ve siyanobakterilerin biyokütle verimliliğinin arttırması, ileri teknikle tasarlanan ve düşük maliyetli teknolojilerle geliştirilen fotobiyoreaktör ile sağlanabilir.Öğe Carotenoid Profile in Prochlorococcus sp and Enrichment of Lutein Using Different Nitrogen Sources(Springer, 2016) Erdogan, Aysegul; Demirel, Zeliha; Eroglu, Ahmet E.; Dalay, Meltem ConkVarious carotenoids of the cyanobacterium Prochlorococcus sp. are identified using chromatographic/spectroscopic techniques and quantified using HPLC-DAD. In the present study, beta-apo-8'-carotenal was used as internal standard. Identification of carotenoids was carried out by comparing the retention time, absorption spectra, and mass spectra of unknown peaks with reference standards. All-trans-lutein was found to be the major carotenoid in this cyanobacterium, and, therefore, algal productivity and the potential for lutein accumulation were analyzed as a function of different nitrogen sources such as nitrate, nitrite, ammonia, and urea for cultivation. Among them, urea clearly led to the best lutein accumulation. According to the experimental evidence, lutein increased from 2.54 to 3.34 mg g(-1) in the cyanobacteria when urea was used as the nitrogen source.Öğe Chlorella sorokiniana’ nın İzolasyonu, Moleküler Tanılanması, Fototrofik, Miksotrofik ve Heterotrofik Üretimi(2021) Bingül, Döndü Yalçın; Demirel, Zeliha; Dalay, Meltem Conkİzmir’in Gümüldür bölgesinden alınan su örneğinde, seyreltme ve dökme plaka yöntemleri kullanılarak mikroalg izolasyonu yapılmıştır. Işık mikroskobuyla morfolojik olarak değerlendirilen türün Chlorella sp. olduğu saptanmıştır. Moleküler yöntemlerle mikroalg DNA’sı izole edilerek 16S ve 18S rRNA gen bölgeleri PCR’da çoğaltılmıştır. Bu dizinin sekanslanması ve filogenetik olarak değerlendirilmesi sonucu Chlorella sorokiniana olduğu belirlenmiştir. Aksenik C. sorokiniana elde etmek için santrifüj ile yıkama, antibiyotik ile muamele, agar ortamında büyütme ve tek hücre izolasyonu gibi farklı yöntemler kullanılarak aksenikleştirme işleminden başarılı sonuçlar elde edilmiştir. Fototrofik C. sorokiniana’ dan elde edilen biyokütle (0,19 g L-1) ve spesifik büyüme hızı (0,78 gün-1), miksotrofik C. sorokiniana’ dan elde edilen biyokütle (0,31 g L-1) ve spesifik büyüme hızı(1,3 gün-1), heterotrofik C. sorokiniana’ dan elde edilen biyokütle (0,6 g L-1) ve spesifik büyüme hızı (2,52 gün-1) olarak belirlenmiştir. Elde edilen bulgulara göre aksenik mikroalg C. sorokiniana’ nın farklı üretim koşullarındaki biyokütle verimliliği şu şeklide sıralanabilir: heterotrofi>miksotrofi>fototrofi.Öğe Converted carotenoid production in Dunaliella salina by using cyclization inhibitors 2-methylimidazole and 3-amino-1,2,4-triazole(Tubitak Scientific & Technical Research Council Turkey, 2017) Yildirim, Arzu; Akgun, Ismail Hakki; Dalay, Meltem ConkCarotenoids are vital for most photosynthetic organisms because of their crucial role in prevention of the damage caused by excess light or stress conditions like heat or nutrient deprivation. Some of them are also valuable for biotechnology with respect to their colorful feature and antioxidant properties. In this study, a natural beta-carotene producer, green microalga Dunaliella salina, was evaluated for its potential to produce different valuable carotenoids through the inhibition of cyclization reactions in the carotenoid pathway by the chemical inhibitors 2-methylimidazole (2MI) and 3-amino-1,2,4-triazole (Amitrol). 2MI was shown to be effective on lutein accumulation in D. salina cultures grown at high temperature, without affecting cell viability. Addition of 2MI to the culture at 1 mM concentration resulted a 1.7-fold increase in lutein content in the cell with the highest amount of 3.45 pg/cell, and an associated decrease in beta-carotene content suggesting that this inhibitor is more effective on lycopene beta-cyclase activity, thus shifting the pathway from beta-carotene arm to the alpha-carotene direction. The results of this study may give the opportunity to use D. salina for the production of valuable carotenoids other than beta-carotene.Öğe The cultivation of Nitzchia communis in flat-plate photobioreactor and evaluation of different disruption techniques for lipid analysis(Elsevier Science Bv, 2014) Demirel, Zeliha; Imamoglu, Esra; Dalay, Meltem ConkÖğe Development of an efficient process to extract C-phycocyanin from marine cyanobacterial strains and evaluation of its bioactive potential(Wiley, 2024) Khazi, Mahammed Ilyas; Demirel, Zeliha; Liaqat, Fakhra; Eltem, Rengin; Dalay, Meltem ConkBACKGROUNDPhycocyanin (PC), a natural blue photosynthetic pigment found in cyanobacteria, rhodophyta and cryptophyta has numerous applications in biotechnology and the food industry. The phycocyanin extraction method has a significant impact on its bioactivities, purity index, cost and potential applications; thus, the development of an efficient extraction strategy continues to be a primary research goal.RESULTSThis study evaluated the efficacy of different methods for the extraction of cyanobacterial phycocyanin (C-PC) from three marine cyanobacterial isolates, namely Arthrospira platensis, Phormidium sp. and Pseudoscillatoria sp. wet biomass. The pretreatment step of soaking biomass in extraction buffer for 60 min, followed by a combination of freeze-thaw (one cycle; 2 h) and sonication (2 min) treatment was found to be the most effective extraction strategy, producing the highest C-PC yield (16.19 +/- 0.34%, 15.89 +/- 0.61% and 15.56 +/- 0.69% dry cell weight for strains A. platensis, Phormidium sp. and Pseudoscillatoria sp., respectively). Furthermore, a biomass-to-solvent ratio of 0.02 g mL-1 was optimal to attain food-grade purity ((A620/A280) >= 0.7). Bioactivity evaluation of crude and purified C-PC exhibited its potential as antioxidant compounds and as an antimicrobial agent with significant inhibitory effects against various pathogenic microorganisms.CONCLUSIONThe study proposed an efficient and cost-effective C-PC extraction process for cyanobacteria and highlighted the potential of C-PC as a valuable bioactive compound with various applications. (c) 2024 Society of Chemical Industry (SCI).Öğe Effect of different abiotic conditions on biomass and fucoxanthin content of Amphora capitellata(2022) Demirel, Zeliha; Erdoğan, Ayşegül; Karataş, Ayça Büşra; Dalay, Meltem ConkThe aim of the study was to investigate the influence of physical conditions such as aeration rate (1, 3, 5 L/min) as well as chemical conditions including sodium nitrite (NaNO2), urea (CH4N2O) and ammonium chloride (NH4Cl) on the biomass productivity and fucoxanthin concentration of A. capitellata. The optimum cultures were cultivated in f/2 medium using sodium nitrate (NaNO3) in 2 L bubbling bottle photobioreactors under the light intensity of 100 µE/ m2s with aeration rate of 2 L/min. All the bottles were then incubated at 22.0±2°C, under the light intensities of 300 µE/m2s with three different airflow rates of 1, 3, 5 L/min for 16 days. And then, culture medium was prepared with three different nitrogen sources to achieve higher biomass productivity. During the production of A. capitellata, the maximum specific growth rate of 0.166 day-1, which conformed to the doubling time of 4.166 day, was achieved at the light intensity of 300 µE/m2s with an aeration rate of 1 L/min when sodium nitrate was used. Chlorophyll-a and fucoxanthin contents were also at the highest level in the same light intensity. Dry biomass amount reached the maximum level of 0.66±0.17 g/L in case of NaNO2. In this study, it was defined that the airflow rate of 1 L/min, the light intensity of 300 µE/m2s and sodium nitrate (NaNO3) were the optimum values not only for the growth of A. capitellata cells but also for the production of biomass and a higher fucoxanthin concentration.Öğe Effects of Extraction Methods and Conditions on Bioactive Compounds Extracted from Phaeodactylum tricornutum(Slovensko Kemijsko Drustvo, 2020) Akyil, Saniye; Ilter, Isil; Koc, Mehmet; Demirel, Zeliha; Erdogan, Aysegul; Dalay, Meltem Conk; Ertekin, Figen KaymakThe effect of homogenization, ultrasound and microwave extraction methods and conditions on fucoxanthin content, total phenolic content and antioxidant activity of extracts obtained from Phaeodactylum tricornutum were investigated in this study. The solvent/biomass ratio was the most effective parameter on fucoxanthin content, total phenolic content and antioxidant activity. The maximum fucoxanthin content (5.60 +/- 0.06 mg/g) and antioxidant activity (763.00 +/- 15.88 EC50 mu g/mL extract) were obtained with the homogenization extraction method whose optimum conditions were 1.93% biomass/solvent ratio, -5200 rpm homogenization rate and 14.2 min extraction time. Although the ultrasonic extraction method has reached the approximately same level of fucoxanthin content (5.24 +/- 0.07 mg/g)), TPC (67.68 +/- 1.58 mg gallic acid/L) and antioxidant activity (619.90 +/- 17.16 EC50 mu g/mL extract) at an amplitude of 55.72%, a higher biomass/solvent ratio (2.72%) and a longer extraction time (17.37 min) have been required. The lowest fucoxanthin content, total phenolic content and antioxidant activity were determined for the microwave extraction method.Öğe Enhanced Microalgal Lipid Production in Internally Illuminated Airlift Photobioreactor(Marine Technology Soc Inc, 2019) Deniz, Irem; Demirel, Zeliha; Imamoglu, Esra; Dalay, Meltem ConkInternal illumination systems are being considered for use as an alternative light supply technique in microalgal products. The main goal of the study was to analyze the roles of different light wavelengths in internally illuminated airlift photobioreactors (PBRs) providing the light energy in an efficient way for the biomass production, lipid yield, and fatty acid composition of Amphora capitellata. The maximum chlorophyll-a concentration per unit biomass (2.62 +/- 0.16 mg L-1) was obtained under red light, which was only 14% higher than under blue light in internally illuminated airlift PBR, whereas low chlorophyll-a content was found under white light. Maximum specific growth rate of 0.317 day(-1), which corresponded to a doubling time of 2.185 days, was obtained under red light for A. capitellata. It was found that lipid content increased with decreasing growth rate for A. capitellata. Palmitic acid (C16:0) and palmitoleic acid (C16:1) were the principal fatty acids accounting for between 31%-33% and 31%-32% of total fatty acids, respectively. It is important to underline that red and blue light spectrum ranges contribute to improved biomass growth, whereas white light has the potential to support lipid content of diatoms.Öğe Evaluation of culture conditions of locally isolated Dunaliella salina strain EgeMacc-024(Elsevier, 2014) Imamoglu, Esra; Demirel, Zeliha; Dalay, Meltem ConkThe aim of this study was to optimize physical parameters such as light intensity, temperature and agitation rate which might affect the cultivation of Dunaliella sauna strain EgeMacc-024. For this purpose, a set of experiments were designed by central composite design using response surface methodology to statistically evaluate the findings. The optimal growth conditions were found at 22.09 degrees C under the light intensity of 55.75 mu mol photons m(-2) s(-1) at the agitation rate of 148.73 rpm with the chlorophyll-a concentration of 6.47 mg/L, whereas the protein amount was 14.87 mu g/100 mu L at 27.97 degrees C under the light intensity of 57.5 mu mol photons m(-2) s(-1) with the agitation rate of 166.08 rpm for D. salina. The maximum specific growth rate of 0.22 day(-1), which corresponded to the doubling time of 3.15 day, was obtained for D. salina under determined conditions. (C) 2014 Elsevier B.V. All rights reserved.Öğe Evaluation of growth and phycobiliprotein composition of cyanobacteria isolates cultivated in different nitrogen sources(Springer, 2018) Khazi, Mahammed Ilyas; Demirel, Zeliha; Dalay, Meltem ConkPhycobiliproteins, light-harvesting pigments found in cyanobacteria and in some eukaryotic algae, have numerous commercial applications in food, cosmetic, and pharmaceutical industries. Colorant production from cyanobacteria offers advantages over their production from higher plants, as cyanobacteria have fast growth rate and high photosynthetic efficiency and require less space. In this study, three cyanobacteria strains were studied for phycobiliprotein production and the influence of sodium nitrate, potassium nitrate and ammonium chloride on the growth and phycobiliprotein composition of the strains were evaluated. In the batch culture period of 12 days, Phormidium sp. and Pseudoscillatoria sp. were able to utilize all tested nitrogen sources; however, ammonium chloride was the best nitrogen source for both strains to achieve maximum growth rate mu = 0.284 +/- 0.03 and mu = 0.274 +/- 0.13 day(-1), chlorophyll a 16.2 +/- 0.5 and 12.2 +/- 0.2 mg L-1, and phycobiliprotein contents 19.38 +/- 0.09 and 19.99 +/- 0.14% of dry weight, whereas, for Arthrospira platensis, the highest growth rate of mu = 0.304 +/- 0.0 day(-1), chlorophyll a 19.1 +/- 0.5 mg L-1, and phycobiliprotein content of 22.27 +/- 0.21% of dry weight were achieved with sodium nitrate. The phycocyanin from the lyophilized cyanobacterial biomass was extracted using calcium chloride and food grade purity (A (620)/A (280) ratio > 0.7) was achieved. Furthermore, phycocyanin was purified using two-step chromatographic method and the analytical grade purity (A (620)/A (280) ratio > 4) was attained. SDS-PAGE demonstrated the purity and presence of two bands corresponding to alpha- and beta-subunits of the C-phycocyanin. The results showed that Phormidium sp. and Pseudoscillatoria sp. could be good candidates for phycocyanin production.Öğe Fucoxanthin Content of Cylindrotheca Closterium and Its Oxidative Stress Mediated Enhancement(Central Fisheries Research Inst, 2016) Erdogan, Aysegul; Demirel, Zeliha; Dalay, Meltem Conk; Eroglu, Ahmet E.Production of fucoxanthin by diatoms has become an alternative research area due to their low cost, convenience and diversity. The fucoxanthin content of Cylindrotheca closterium and its enhancement by altering the cultivation conditions via oxidative stress were investigated in this study. For this purpose, the extraction parameters were optimized and the highest fucoxanthin concentration (6.58 mg g(-1)) was achieved within 15.0 minutes at 40 degrees C. Then, this yield reached to 10.15 mg g(-1) in the presence of NaOCl and Fe2+. It is worth noting that, this is the first time that the effect of oxidative stress on fucoxanthin production in diatom has been studied according to our knowledge. Therefore, the results of this study and the discussion about the mechanisms can be a reference for the enrichment of fucoxanthin from other diatoms.Öğe Growth Kinetics of Nanofrustulum Shiloi Under Different Mixing Conditions in Flat-plate Photobioreactor(Inst Tecnologia Parana, 2020) Demirel, Zeliha; Imamoglu, Esra; Dalay, Meltem ConkDiatoms are the major group of microalgae which have been utilized by the potential applications as food industries, aquatic feeds, cosmetics, biofuels, and pharmaceuticals. in this study, current approaches were made in order to determine growth rate, biomass productivity, protein, carbohydrate, lipid and fatty acid composition for Nanofrustulum shiloi cultures using both aeration and mixing conditions in flat-plate photobioreactor (PBR). Physical (the intensity of aeration, mixing, light intensity etc.) and chemical (nutritional materials) factors are affecting the growth and bioproduct contents of a diatom. Biomass and lipid productivities of N. shiloi were measured as 31.29 and 36.9622 +/- 0.0598 mg L(-1)day(-1) in flat-plate PBR having the combination of aeration and stirring system, respectively. A slightly higher amount of saturated fatty acids was detected in PBR having only bubbling system while the increase of mono- and poly- unsaturated fatty acids were found in PBR having the combination of aeration and stirring system. Flat-plate PBR design was also investigated for improving not only biomass but also the lipid productivity of N. shiloi.Öğe In vitro evaluation of Spirulina platensis extract incorporated skin cream with its wound healing and antioxidant activities(Taylor & Francis Ltd, 2017) Gunes, Seda; Tamburaci, Sedef; Dalay, Meltem Conk; Gurhan, Ismet DelilogluContext: Algae have gained importance in cosmeceutical product development due to their beneficial effects on skin health and therapeutical value with bioactive compounds. Spirulina platensis Parachas (Phormidiaceae) is renowned as a potential source of high-value chemicals and recently used in skincare products. Objective: This study develops and evaluates skin creams incorporated with bioactive S. platensis extract. Materials and methods:Spirulina platensis was cultivated, the aqueous crude extract was prepared and in vitro cytotoxicity of S. platensis extract in the range of 0.001-1% concentrations for 1, 3 and 7d on HS2 keratinocyte cells was determined. Crude extracts were incorporated in skin cream formulation at 0.01% (w/w) concentration and in vitro wound healing and genotoxicity studies were performed. Immunohistochemical staining was performed to determine the collagen activity. Results: 0.1% S. platensis extract exhibited higher proliferation activity compared with the control group with 198% of cell viability after 3 d. Skin cream including 1.125% S. platensis crude extract showed enhanced wound healing effect on HS2 keratinocyte cell line and the highest HS2 cell viability % was obtained with this concentration. The micronucleus (MN) assay results indicated that S. platensis extract incorporated creams had no genotoxic effect on human peripheral blood cells. Immunohistochemical analysis showed that collagen 1 immunoreactivity was improved by increased extract concentration and it was strongly positive in cells treated with 1.125% extract incorporated skin cream. Conclusions: The cell viability, wound healing activity and genotoxicity results showed that S. platensis incorporated skin cream could be of potential value in cosmeceutical and biomedical applications.Öğe Influence of Media and Temperature on the Growth and the Biological Activities of Desmodesmus protuberans (F.E. Fritsch & M.F. Rich) E. Hegewald(2018) Demirel, Zeliha; Yılmaz, Ferda Fethiye; Özdemir, Güven; Dalay, Meltem ConkThe aim of this study is to determine different culture media and temperature values on the growth rate of Desmodesmus protuberans (F.E. Fritsch & M.F.Rich) E. Hegewald, and to investigate antimicrobial and antioxidant potency of the crude extracts. The microalga isolates from Lake Eğirdir in Isparta (Turkey) was identified as D. protuberans and included in Ege University Microalgae Culture Collection. D. protuberans was cultivated at two temperature regimes (22 and 28ºC) and growth media (BBM, BG-11 and RD medium) under the light intensity of 75 ?mol m-2s-1 for testing the impact of different environmental conditions on the growth rate. All of the productions of D. protuberans biomass were extracted with methanol and investigated the antimicrobial and antioxidant activity. Antimicrobial activities of the extracts of alga were tested by disc diffusion assay against five Gram-positive and four Gram-negative bacterial strains and against the yeast Candida albicans. The methanol extract of the biomass from BBM medium (28°C) showed the highest growth inhibition effect on C. albicans, while RD medium (22°C) extract showed the highest antioxidant activity. These results demonstrated that the differences in the bioactivity of biomasses are stemmed from different temperature and media conditions.Öğe Influence of Media and Temperature on the Growth and the Biological Activities of Desmodesmus protuberans (F.E. Fritsch & M.F. Rich) E. Hegewald(2018) Demirel, Zeliha; Yılmaz, Ferda Fethiye; Özdemir, Güven; Dalay, Meltem ConkThe aim of this study is to determine different culture media and temperature values on the growth rate of Desmodesmus protuberans (F.E. Fritsch & M.F.Rich) E. Hegewald, and to investigate antimicrobial and antioxidant potency of the crude extracts. the microalga isolates from Lake Eğirdir in Isparta (Turkey) was identified as D. protuberans and included in Ege University Microalgae Culture Collection. D. protuberans was cultivated at two temperature regimes (22 and 28ºC) and growth media (BBM, BG-11 and RD medium) under the light intensity of 75 ?mol m-2s-1 for testing the impact of different environmental conditions on the growth rate. All of the productions of D. protuberans biomass were extracted with methanol and investigated the antimicrobial and antioxidant activity. Antimicrobial activities of the extracts of alga were tested by disc diffusion assay against five Gram-positive and four Gram-negative bacterial strains and against the yeast Candida albicans. the methanol extract of the biomass from BBM medium (28°C) showed the highest growth inhibition effect on C. albicans, while RD medium (22°C) extract showed the highest antioxidant activity. These results demonstrated that the differences in the bioactivity of biomasses are stemmed from different temperature and media conditions.Öğe Influence of Media and Temperature on the Growth and the Biological Activities of Desmodesmus protuberans (FE Fritsch & MF Rich) E. Hegewald(Central Fisheries Research Inst, 2018) Demirel, Zeliha; Yilmaz, Ferda Fethiye; Ozdemir, Guven; Dalay, Meltem ConkThe aim of this study is to determine different culture media and temperature values on the growth rate of Desmodesmus protuberans (F.E. Fritsch & M.F.Rich) E. Hegewald, and to investigate antimicrobial and antioxidant potency of the crude extracts. The microalga isolates from Egirdir Lake in Isparta (Turkey) was identified as D. protuberans and included in Ege University Microalgae Culture Collection. D. protuberans was cultivated at two temperature regimes (22 and 28 degrees C) and growth media (BBM, BG-11 and RD medium) under the light intensity of 75 mu mol m(-2) S-1 for testing the impact of different environmental conditions on the growth rate. All of the productions of D. protuberans biomass were extracted with methanol and investigated the antimicrobial and antioxidant activity. Antimicrobial activities of the extracts of alga were tested by disc diffusion assay against five Gram-positive and four Gram-negative bacterial strains and against the yeast Candida albicans. The methanol extract of the biomass from BBM medium (28 degrees C) showed the highest growth inhibition effect on C. albicans, while RD medium (22 degrees C) extract showed the highest antioxidant activity. These results demonstrated that the differences in the bioactivity of biomasses are stemmed from different temperature and media conditions.Öğe Influences of different stress media and high light intensities on accumulation of astaxanthin in the green alga Haematococcus pluvialis(Elsevier Science Bv, 2009) Imamoglu, Esra; Dalay, Meltem Conk; Sukan, Fazilet VardarHaematococcus pluvialis Flotow is used in the aquaculture, pharmaceutical and cosmetic industries. The aim of this study was to compare the effect of various stress media and high light intensities on astaxanthin accumulation. The experimental design was achieved by four different stress media and two different light intensities for 14 days of induction period. The astaxanthin concentrations of 29.62 mg g(-1) and 30.07 mg g(-1) were obtained in distilled water with CO(2) and N-free medium, respectively, with no significant difference between them at 546 mu mol photons m(-2)s(-1). Because of the morphological changes of H. pluvialis, microscopic observation was considered during the induction period to facilitate the selection of stress medium. It was clear that the rate of astaxanthin accumulation was much faster in distilled water with the addition Of CO(2). The main point is that, this medium is more economical than others, especially for the large-scale productions.
