Ünsal AÇIKEL, Mehtap ERŞAN

R. delemar 'IN ASİT FOSFATAZ ÜRETİMİ ve Zn(II) BİYOBİRİKİMİNİN CEVAP YÜZEY YÖNTEMİ KULLANARAK OPTİMİZE EDİLMESİ

Cumhuriyet Üniversitesi, Kimya Mühendisliği Bölümü, Sivas, Turkey mersan@cumhuriyet.edu.tr, uacikel@cumhuriyet.edu.tr (Geliş/Received: 08.05.2013; Kabul/Accepted: 05.12.2013) ÖZET R. delemar ın asit fosfataz aktivitesi, Zn(II) biyobirikimi ve üremesi, pH, sıcaklık ve başlangıç metal iyonu konsantrasyonunun fonksiyonu olarak araştırıldı. Deney tasarımı Cevap Yüzey Yöntemi (CYY) ve BoxBehnken tasarımına göre yapıldı. Önerilen matematiksel modeller varyans analizi (ANNOVA) istatistiksel yöntemi ile değerlendirilmiştir. Asit fosfataz aktivitesi için doğrusal, mikroorganizma derişimi ve Zn(II) biyobirikimi için kuadratik eşitliğe tam bir uyum gözlenmiştir. R. delemar ın üremesi asit fosfataz üretimi ve Zn(II) biyobirikimi için optimum pH 5,03, sıcaklık 31,82 o C ve başlangıç Zn(II) iyonu konsantrasyonu 30,15 mg/L olarak bulunmuştur. Bu koşullarda elde edilen maksimum asit fosfataz aktivitesi 794,098 µmol/L-dak, mikroorganizma konsantrasyonu 3,203 g/L ve biyobiriktirilen Zn(II) miktarı 17,62 mg/L olarak bulunmuştur. Deney doğrulama deneyi yapılarak sonuçların duyarlılığı ve geçerliliği gösterilmiştir.

OPTIMIZATION OF ACID PHOSPHATASE PRODUCTION AND ZN(II) BIOACCUMULATION by R. delemar USING RESPONSE SURFACE METHOD

Acid phosphatase activity, Zn (II) bioaccumulation and growth of R. delemar were investigated as a function of pH, temperature and initial Zn(II) ion concentration. Experimental design was performed by response surface method (RSM) and Box-Behnken design. The proposed mathematical models were evaluated by analysis of variance (ANNOVA) statistically method. The best fit for acid phosphatase activity was obtained by linear model, the Zn(II) bioaccumulation and microorganism growth were characterized by quadratic equations. The optimum conditions for acid phosphatase activity, Zn(II) bioaccumulation and growth of R. delemar were found to be pH 5,03, 31,82 o C and an initial Zn(II) ion concentration of 30,15 mg/L. At these conditions the maksimum acid phosphatase activity Zn(II) bioaccumulation and microorganism concentration were determined as 794,098 mmol / L-min, 17,62 mg / L and 3,2038 g / L respectively. To test sensivity and validity of the optimum conditions the validation experiments were performed.

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