ß-Glycosidase (amygdalase and linamarase) from Endomyces fibuliger (LU677): Formation and crude enzyme properties
Küçük Resim Yok
Tarih
1998
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Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
In our previous studies, the yeast Endomyces fibuliger LU677 was found to degrade amygdalin in bitter apricot seeds. The present investigation shows that E. fibuliger LU677 produces extracellular ß-glycosidase activity when grown in malt extract broth (MEB). Growth was very good at 25°C and 30°C and slightly less at 35°C. When grown in MEB of pH 5 and pH 6 with addition of 0, 10 or 100 ppm amygdalin, E. fibuliger produced only slightly more biomass at pH 5, and was only slightly inhibited in the presence of amygdalin. Approximately, 60% of the added amygdalin was degraded (fastest at 35°C) during an incubation period of 5 days. Supernatants of cultures grown at 25°C and pH 6 for 5 days were tested for the effects of pH and temperature on activity (using amygdalin, linamarin and prunasin as substrates). Prunase activity had two pH optima (pH 4 and pH 6), amygdalase and linamarase only one each at pH 6 and pH 4-5 respectively. The linamarase activity evolved earlier than amygdalase (2 days and 4 days respectively). The data thus indicate the presence of at least two different glycosidases having different pH optima and kinetics of excretion. In the presence of amygdalin, lower glycosidase activities were generally produced. However, the amygdalin was degraded from the start of the growth, strongly indicating an uptake of amygdalin by the cells. The temperature optimum for all activities was at 40°C. Activities of amygdalase (assayed at pH 4) and linamarase (at pH 6) evolving during the growth of E. fibuliger were generally higher in cultures grown at 25°C and 30°C. TLC analysis of amygdalin degradation products show a two-stage sequential mechanism as follows: (1) amygdalin to prunasin and (2) prunasin to cyanohydrin.
Açıklama
Anahtar Kelimeler
Kaynak
Applied Microbiology and Biotechnology
WoS Q Değeri
Scopus Q Değeri
N/A
Cilt
49
Sayı
2
