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    Assessment of light intensity and salinity regimes on the element levels of brown macroalgae, Treptacantha barbata: Application of response surface methodology (RSM)
    (Sociedade Brasileira de Ciencia e Tecnologia de Alimentos, SBCTA, 2021) Ak, İlknur; Cankırılıgil, Ekrem Cem; Türker, Gülen; Sever, Onur
    In this research, the effect of light intensity and salinity regimes on the element levels of Treptacantha barbata (formerly Cystoseira barbata) was studied, and the elemental compositions of this brown alga collected from wild stocks also compared with cultured ones. In culture trials, 11 different experiments that have ranges of light intensity as 50 to 150 µmol photon m-2s-1 and salinity as 24 ‰ to 42 ‰ were designed according to response surface methodology (RSM). Our results show that the element accumulation with changes of light intensity and salinity on the T. barbata was modeled. Most of the elements were affected by the salinity instead of light intensity. All macro and microelements were detected within the recommended dosages and exposure limits. In toxic elements, the least accumulations of Al, As, Cd, and Pb were observed in low light and salinity. Also, the levels of all toxic elements, including trace elements that exceed limits, can be reduced with using these models. The most effective experiment was found as 52.0001 µmol photon m-2s-1 light and 24.086 ‰ salinity for minimized toxic element accumulation on T. barbata with 0.869 desirability.
  • [ X ]
    Öğe
    Çanakkale ilinde dağilim gösteren yeşil alglerden codium fragile subsp. Fragile'in element içeriklerinin araştırılması
    (Çanakkale Onsekiz Mart Üniversitesi, 2024) Sever, Onur; Ak, İlknur
    Bu tez çalışmasında, Çanakkale Boğazı Kepez bölgesinden toplanan Codium fragile subsp. fragile'in mevsimsel mineral ve ağır metal içerikleri incelenmiştir. Çalışmada Ca, P, Cr, Fe, Cu, Mn, Zn ve Al elementlerinin mevsimsel dağılımları detaylı olarak analiz edilmiştir. Örneklerin mineral içerikleri incelendiğinde, Na, Ca, K, P, Co, Fe, Cu, Ni, Mn, Zn ve Al elementlerinin mevsimsel farklılıklar gösterdiği belirlenmiştir (p<0,05). Bahar mevsiminde Na (2749,20±490,40 ppm), K (291,68±37,97 ppm), Ca (361,91±93,44 ppm), P (31,57±2,48 ppm), Co (29,42±5,82 ppb), Cu (202,85±7,20 ppb), Fe (37,35±30,38 ppb), Mn (2,09±0,12 ppm), Ni (172,33±33,25 ppb), Al (23,02±4,78 ppm) ve Zn (543,93±44,66 ppb) en yüksek seviyelerde tespit edilmiştir. Mg, B ve Cr elementleri mevsimsel olarak anlamlı bir farklılık göstermemiştir (p>0,05). Kış mevsiminde elementler Na > K > Ca > Mg > P > Al > Mn > B > As > Zn > Cu > Ni > Cr > Fe > Co şeklinde sıralanmıştır. Bahar mevsiminde Na > Ca > K > Mg > P > Al > Mn > B > As > Zn > Cu > Ni > Cr > Fe > Co, yaz mevsiminde Na > Ca > K > Mg > P > Al > Mn > B > Zn > As > Cr > Ni > Cu > Fe > Co ve sonbahar mevsiminde Na > Mg > Ca > K > P > Al > B > Mn > Zn > As > Cu > Ni > Cr > Fe > Co sıralamaları gözlemlenmiştir. Anahtar Kelimeler: Codium fragile, Element İçerikleri, Mevsimsel Değişim, Yeşil Makroalgler
  • [ X ]
    Öğe
    Enhancement of antioxidant properties of Gongolaria barbata (Phaeophyceae) by optimization of combined light intensity and salinity stress
    (Taylor & Francis Ltd, 2022) Ak, Ilknur; Cankiriligil, Ekrem Cem; Turker, Gulen; Sever, Onur; Abomohra, Abdelfatah
    The present study aimed to optimize the light intensity coupled with different salinity regimes for enhanced growth and antioxidant properties of the brown seaweed Gongolaria barbata. Five experimental trials (T-1-T-5) were suggested using response surface methodology, where growth rate and antioxidant properties of G. barbata were evaluated in each run at the end of the experiment. The model for growth rate showed differences not statistically significant among all studied groups. However, concentration of methanol extract needed to scavenge 50% of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals (IC50), total phenolics, total flavonoids, total carotenoids, chlorophyll a and chlorophyll c showed significant differences among the five studied groups. Total phenolic and flavonoid contents were primarily affected by light, showing the highest values of 2.08 mg gallic acid equivalent g(-1) and 2.41 mg rutin g(-1) at 50 mu mol photon m(-2) s(-1). However, salinity stress showed a more pronounced impact on pigments. DPPH scavenging activity was influenced by the concentration of other compounds, which showed a significant increase by 34% in group T-4. The present study recommended light intensity of 53.86 mu mol photons m(-2) s(-1) at 24.02 parts per thousand salinity as the optimum conditions to achieve the maximum antioxidant activity along with phenolic and flavonoid contents (desirability = 0.82), without significant impact on the growth.