The Relationship of Pellet Morphology to Polygalacturonase Production of Rhizopus Oryzae in Various Media Compositions (in English)

Öz

Various media parameters affecting the polygalacturonase (PG) production of Rhizopus oryzae, were stud­ied and their relation to pellet morphology was investigated. The basal medium in the absence of Mg+2 and in the presence of 4 mg/kg of Zn +2 at pH 3, resulted into maximum PG activity (11.53 U/ml). A composi­tion of 14.78 g/l of glucose, 10 g/l of galactose, 5 g/l mannose, 0.5 g/l of arabinose and 19.73 g/l of xylose resulted into maximum PG activity (27.94 U/ml) when used as combined carbon sources. Corn meal as the nitrogen source, promoted PG synthesis where it resulted into 33 % more activity than corn steep liquor (CSL) and (NH4)2SO4 which were the next highest promoter. The highest number of pellets with an aver­age mean diameter of 1.25±0.25 mm was obtained with the formulation containing (NH4)2SO4 and 25 g/l of glucose. Yeast extract on the other hand resulted into pellet formation with an average mean diameter of 1.75±0.25 mm at higher glucose concentration (50 g/l). The interactive effect of suitable carbon source (glucose) with suitable nitrogen source (corn meal) enhanced the PG activity 4 times more than the basal medium with pellets of 1.44±0.35mm in average diameter.

Anahtar Kelimeler

• Rhizopus oryzae, polygalacturonase, pellet morphology

Değişik Ortam Komposizyonunda Rhizopus oryzae’nin Poligalakturonaz Üretimi ile Pellet Morfolojisinin İlişkisi (İngilizce)

Öz

Bu çalışmada, ortam kompozisyonunu belirleyen değişik faktörlerin Rhizopus oryzae pellet morfolojisine ve poligalakturonaz (PG) enzimi üretimine olan etkisi incelenmiştir. En yüksek PG aktivitesine (11.53 U/ml) 4 mg/kg Zn+2 içeren, Mg+2 içermeyen ve pH 3 olan basal ortamında ulaşılmıştır. Karbon kaynağı olarak 14.78 g/l glukoz, 10 g/l galaktoz, 5 g/l mannoz, 0.5 g/l arabinoz ve 19.73 g/l ksilozun birlikte kullanılmıyla da en yüksek PG aktivitesine (27.94 U/ml) ulaşılmıştır. Mısır unu nitrojen kaynağı olarak PG sentezini tetik­lemede oldukça etkili olup bir diğer yüksek tetikleyici olan mısır maserasyon sıvısı (CSL) ve (NH4)2SO4’den %33 daha fazla aktivite vermiştir. (NH4)2SO4 and 25 g/l glukoz içereren formulasyon ortalama çapı 1.25± 0.25 olan en fazla sayıda pellet oluşumunu sağlamıştır. Ortalama çapı 1.75±0.25 mm olan pelletlerin oluşu­mu ise yüksek glukoz konsantrasyonuna sahip (50g/l) maya ekstraktı içeren formulasyon ile elde edilmiştir. Uygun karbon kaynağının (glukoz) uygun nitrojen kaynağı (mısır unu) ile interaktif etkisi PG aktivitesini basal ortama göre 4 kat daha arttırmış, ortalama çapı 1.44±0.35mm olan pelletler oluşturmuştur.

Anahtar Kelimeler

• Rhizopus oryzae, poligalaktronaz, pellet morfolojisi

Kaynakça

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