Şevket GÖKPINAR, Tolga GÖKSAN, Sema CİRİK, Bircan ÖZBAŞ

Nannochloropsis sp. (Eustigmatophyta)'nin kış döneminde tubular fotobiyoreaktörde büyüme özelliği

Özet: Ülkemizdeki deniz balıkları larval yetiştiricilik kuiuçkahanelerinde mikroalg üretimi, kurulum maliyetlerinin nispeten daha düşük olması nedeni ile şeffaf polietilen torbalarda gerçekleştirilmektedir. Fakat fototrofik üretim açısından verimsiz sayılan bu tip yöntemlerdeki geniş alan ve yüksek işgücü gereksinimi önemli bir maliyet girdisini oluşturmaktadır. Bu nedenle, tubular sistemler ya da panel tipi fotobiyoreaktörler, daha yüksek aydınlanma yüzeyine sahip, yüksek fotosentez hızında ve yüksek verimlilikle çalışan biyoreaktör sistemlerdir. Denemelerde, ticari bir mikroalg üretim sistemi olan, 600 litre hacme ve 3 cm dış çapa sahip tubular fotobiyoreaktör sistemi (BioFence) kullanıldı. Çalışmada, Nannochloropsis sp.'nin 47 gün boyunca dış ortamda tubular fotobiyoreaktörde hem kesikli hem de sürekli kültür modunda büyümesi incelendi. Buna göre 16 x 106 hücre mH yoğunlukta başlayan kültür, 22 gün kesikli kültür modunda devam ettirildi ve 320 x 106 hücre mM sayıya ulaştı. Yüksek hücre sayısı nedeni ile tüplerin dibinde hücre birikmeleri meydana geldiği zaman kültürde sürekli üretim moduna geçildi. Kesikli kültürün ardından başlatılan sürekli üretim modu 25 gün devam ettirildi. Sistem günlük ortalama 7 saat gibi düşük bir aydınlanma süresine sahip olmasına rağmen, deneme süresince günde ortalama 208 x 106 hücre mi1 yoğunlukta 81 L kültür alındı. Sonuç olarak, dış ortamdaki bir tubular fotobiyoreaktör sisteminin, şeffaf naylon torbalarda yapılan kültürlere göre daha verimli çalıştığı saptandı.

Anahtar Kelimeler:

büyüme oranı, biyoreaktörler, alg kültürü

Growth characteristic of Nannochloropsis sp. (Eustigmatophyta) in tubular photobioreactor in winter period

Abstract: Growth characteristic of Nannochloropsis sp. (Eustigmatophyta) in tubular photobioreactor in winter period. In our country, microalgae cultures in the marine fish larvae hatcheries are carried out in transparent polyethylene bags due to the low investment costs. However, such methods, which are considered unproductive with respect to phototrophic production, result in high production costs due to the requirements of large area and high manpower, in this respect, tubular and panel photobioreactors are the productive systems having higher illumination surface and running at higher photosynthesis rate. In the experiments, BioFence tubular photobioreactor, a commercial microalgae culture system in 600 liter volume and 3 cm outer diameter, was used. The growth of Nannochloropsis sp., grown in the tubular photobioreactor outdoors in both batch and continuous culture modes during 47 days, was observed in the.study. Accordingly, the cultures that were begun with a cell density of 16 x 106 cells ml-1, were carried out 22 days in batch mode, and reached to 320 x 106 cells ml-1 at end of the trial. The culture was shifted to the continuous mode when the cell precipitation was observed on the bottom of the tubes due to the high cell density. The continuous mode, which was initiated just after the batch mode, was carried out 25 days. Although the system had a short illumination cycle, e.g., 7 hours a day, due to the location the system set up and the season, the system produced 81 L culture per day at an average cell concentration of 208 cells ml-1 during the experiment. As a result, it was shown that a tubular photobioreactor outdoors ran more efficient than the bag cultures.

Keywords:

growth rate, bioreactors, algae culture,

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