Nutrient effects on the growth rates of Marine diatom Chaetoceros gracilis Schütt

Bu çalışmanın amacı, Chaetoceros gracilis Schütt türünün kesikli kültür şartları altında nütrient zenginleştirme denemeleriyle, büyüme kinetikleri hakkında detaylı bilgileri ortaya çıkarmaktır. C. gracilis türü İzmir Körfezi’nden izole edilmiştir. Çalışmamız, incelenecek olan nütrient haricinde diğer nütrientlere doygun ve optimum ışık ve sıcaklık şartlarında gerçekleştirilmiştir. Denemeler sabit sıcaklık odasında 28°C sıcaklıkta ve “gün-ışığı” fluoresan lambalar kullanılarak 1300 ftCd ışık şiddetinde aydınlatılmıştır. Kültürlerin devamı 12:12 aydınlık:karanlık döngüsünde sürdürülmüştür. Stok kültürler ve kesikli kültür denemeleri için Guillard (1975) tarafından tanımlanan f/2 ve h/2 ortamları kullanılmıştır. Üssel büyüme hızları Guillard, 1973’e göre hesaplanmıştır. Herbir nütrient konsantrasyonuna karşılık gelen üssel büyüme hızları grafiğe geçirilmiştir. Monod eğrisi (Monod, 1942) parametreleri transformasyon ve en küçük kareler metodu kullanılarak hesaplandı. Herbir nütrient için bulunan Ks (Yarı-Doygunluk Sabiti) değerleri ise, nitrat için 0.496 μmol NO3—N L-1; amonyum için 0.862 μmol $NH_4^+-N L^{-1}$ ; fosfat için 1.045 μmol $PO_4^{-3}-P L^{-1}$ ve silikat için 0.558 μmol Si L-1 bulunmuştur. Aynı nütrientler dikkate alındığında maksimum büyüme hızı değerleri ise gün-1 olarak sırasıyla, 1.611, 1.332, 1.662 ve 1.757 bulunmuştur.

Deniz diyatomu Chaetoceros gracilis Schütt büyüme hızı üzerine besleyici elementlerin etkileri

The aim of this research is to reveal the detailed informtion on growth kinetics of Chaetoceros gracilis Schütt from the results of nutrient enrichment experiments under batch culture conditions. C. gracilis Schütt was isolated from İzmir Bay. Our studies were performed under optimum light and temperature and nutrient saturated conditions except the nutrient which is investigated. Experiments were conducted in a constant temperature room at 28 °C and irradiated at 1300 ftCd (foot-candle) by daylight fluorescent lambs. Cultures were maintained on a 12:12 light:dark cycle. For stock cultures and batch culture experiments, f/2 and h/2 mediums were used described by Guillard (1975). Exponential growth rates were calculated according to Guillard 1973. The exponential growth rates were plotted against corresponding each nutrient concentrations. Monod curve (Monod, 1942) parameters were calculated by using transformations and the least square method. Ks (Half Saturation Constant) values calculated for each of nutrients were found as follows; 0.496 μmol NO3—N L-1; 0.862 μmol $NH_4^+-N L^{-1}$ ; 1.045 μmol $PO_4^{-3}-P L^{-1}$ and 0.558 μmol Si L-1. Concerning the same nutrients, values of maximum growth rate were found as 1.611 day-1, 1.332 day-1, 1.662 day-1 and 1.757 day-1 respectively.

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Su Ürünleri Dergisi-Cover
  • ISSN: 1300-1590
  • Yayın Aralığı: Yılda 4 Sayı
  • Başlangıç: 1984
  • Yayıncı: Aynur Lök