Aysel UĞUR, Yavuz BEYATLI, Nurettin ŞAHİN

Accumulation of poly-$beta$-hydroxybutyrate in Streptomyces species during growth with different nitrogen sources

Farklı taksonomik özelliklere sahip 27 Streptomyces izolatında Poly--hydroxybutyric asit (PHB) birikimi araştırıldı. Sentezlenen PHB miktarı krotonik asit olarak spektrofotometre ile belirlendi. Denenen izolatların %80’i PHB yi kuru miselyum ağırlığının %0.3-7.6’sı arasında akümüle etti. PHB, seçilmiş Streptomyces izolatları tarafından, farklı azot kaynakları (KNO3, glisin, pepton, proteoz pepton, L-asparagin, tripton ve malt ekstrakt) ve karbon kaynağı olarak da herbiri 2 g/l glukoz içeren besiyerlerinde üretildi. En etkili PHB üretimi kuru miselyum ağırlığının %7.6’sı ile glisin/glukoz ortamında gözlendi. Azotca sınırlandırılmış şartlar Streptomyces gelişimini inhibe ederken, PHB akümülasyonunu teşvik etmiştir. Morfolojik ve biyokimyasal test sonuçlarına göre seçilen izolatlar, Streptomyces halstedii (MU112), S. anulatus (MU117) ve S. rochei (MU119) olarak tanımlandı.

Farklı azot kaynakları ile büyüme sırasında Streptomyces türlerinde poly-$beta$- hydroxybutyratın birikimi

The accumulation of poly-b-hydroxybutyric acid (PHB) in 27 Streptomyces isolates with different taxonomical properties was investigated. The amount of synthesized PHB was determined as crotonic acid by spectrophotometry. Eighty percent of the tested isolates accumulated PHB between 0.3 and 7.6% of dry mycelial weight. PHB was produced by a selectant of Streptomyces isolates in media containing different nitrogen sources (KN$O_3$, glycine, peptone, proteose peptone, L-asparagine, tryptone and malt extract), each combined with 2 g/l glucose as the carbon source. The most effective PHB production was observed on glycine/glucose medium with a 7.6% dry mycelial weight. Nitrogen limiting conditions were inhibitory to Streptomyces growth, but stimulated PHB accumulation. Based on the morphological and biochemical test results, selected isolates were identified as Streptomyces halstedii (MU112), S. anulatus (MU117) and S. rochei (MU119).

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