Authors: AYSEL UĞUR, NURETTİN ŞAHİN, YAVUZ BEYATLI
Abstract: The accumulation of poly-\beta-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 (KNO_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).
Keywords: Poly-\beta-hydroxybutyric acid (PHB), Streptomyces, nitrogen sources
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