Characterization of b-Xylosidase and  a-L-Arabinofuranosidase Activities From  Thermomonospora Fusca BD25

Münir TUNCER

Makale detayları

Characterization of b-Xylosidase and a-L-Arabinofuranosidase Activities From Thermomonospora Fusca BD25

Yazarlar:

Münir TUNCER

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Biology 2000 Vol.24 Issue 4, pp.753-768

Belge Tipi:

Makale

Yayın Tarihi:

3/2000

Belge Dili:

Türkçe

Document ID (Org No.):

2000813934

Sıklık:

İki Aylık

eISSN:

1303-6092

pISSN:

1300-0152

Anahtar kelimeler:

Özet:

 

Thermomonospora fuscaBD25 produces relatively high levels of activity of b-xylosidase and  a-L-arabinofuranosidase. The aim of the work described in this study was to characterize some  properties of b-xylosidase and a-L-arabinofuranosidase produced by T. fusca BD25 when growing on  oat spelt xylan as the main carbon and energy sources. The substrates p-NPX and p-NPA reacted with  b-xylosidase and a-L-arabinofuranosidase with specific activities of 4.01 U mg -1 protein and 0.35 U  mg -1 protein, respectively. The b-xylosidase remained stable at up to 65 °C, but a-L-arabinofuranosidase  lost 10 % of its maximum activity at 55 °C. b-xylosidase and a-L-arabinofuranosidase  activities remained at 86 % and 83 % of their maximum activities after 9 h of  incubation at 50 °C. The maximum relative b-xylosidase activity occurred (0.82 U mg -1 protein) at pH  8.0 with a 50 % decrease of maximum relative activity occurring at pH 4.5 and 10. a-L-arabinofuranosidase  exhibited maximum relative activity (0.136 U mg -1 protein) at pH 9.0 with 54 %  and 55 % activities remaining at pH of 4.5 and 11, respectively. The apparent K m values for the crude  b-xylosidase and a-L-arabinofuranosidase preparations were 0.5 mM of p-NPX and 0.18 mM of  p-NPA, while the V max values were 0.83 mmol p-nitrophenol ml -1 min -1 and 0.04 mmol p-nitrophenol ml -1  min -1 , respectively. The addition of D-xylose (10 mM) to the reaction mixture caused a 10 %  reduction in b-xylosidase activity as the end-product inhibitor. However, a 15 % reduction in a-L-arabinofuranosidase  activity was detected when L-arabinose (10 mM) was added to the reaction  mixture.

 

Thermomonospora fuscaBD25 produces relatively high levels of activity of b-xylosidase and  a-L-arabinofuranosidase. The aim of the work described in this study was to characterize some  properties of b-xylosidase and a-L-arabinofuranosidase produced by T. fusca BD25 when growing on  oat spelt xylan as the main carbon and energy sources. The substrates p-NPX and p-NPA reacted with  b-xylosidase and a-L-arabinofuranosidase with specific activities of 4.01 U mg -1 protein and 0.35 U  mg -1 protein, respectively. The b-xylosidase remained stable at up to 65 °C, but a-L-arabinofuranosidase  lost 10 % of its maximum activity at 55 °C. b-xylosidase and a-L-arabinofuranosidase  activities remained at 86 % and 83 % of their maximum activities after 9 h of  incubation at 50 °C. The maximum relative b-xylosidase activity occurred (0.82 U mg -1 protein) at pH  8.0 with a 50 % decrease of maximum relative activity occurring at pH 4.5 and 10. a-L-arabinofuranosidase  exhibited maximum relative activity (0.136 U mg -1 protein) at pH 9.0 with 54 %  and 55 % activities remaining at pH of 4.5 and 11, respectively. The apparent K m values for the crude  b-xylosidase and a-L-arabinofuranosidase preparations were 0.5 mM of p-NPX and 0.18 mM of  p-NPA, while the V max values were 0.83 mmol p-nitrophenol ml -1 min -1 and 0.04 mmol p-nitrophenol ml -1  min -1 , respectively. The addition of D-xylose (10 mM) to the reaction mixture caused a 10 %  reduction in b-xylosidase activity as the end-product inhibitor. However, a 15 % reduction in a-L-arabinofuranosidase  activity was detected when L-arabinose (10 mM) was added to the reaction  mixture.

Makale detayları

Characterization of b-Xylosidase and a-L-Arabinofuranosidase Activities From Thermomonospora Fusca BD25

Yazarlar:

Münir TUNCER

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Biology 2000 Vol.24 Issue 4, pp.753-768

Belge Tipi:

Makale

Yayın Tarihi:

3/2000

Belge Dili:

Türkçe

Document ID (Org No.):

2000813934

Sıklık:

İki Aylık

eISSN:

1303-6092

pISSN:

1300-0152

b-xylosidase

a-L-arabinofuranosidase

lignocellulose degradation

Thermomonospora fusca

actinomycete.

Sayı

Makale detayları

Characterization of b-Xylosidase and a-L-Arabinofuranosidase Activities From Thermomonospora Fusca BD25

Yazarlar: Münir TUNCER

Yayıncı: TUBITAK

Dergi: Turkish Journal of Biology 2000 Vol.24 Issue 4, pp.753-768

Belge Tipi: Makale

Yayın Tarihi: 3/2000

Belge Dili: Türkçe

Document ID (Org No.): 2000813934

Sıklık: İki Aylık

eISSN: 1303-6092

pISSN: 1300-0152

b-xylosidase

a-L-arabinofuranosidase

lignocellulose degradation

Thermomonospora fusca

actinomycete.

Sayı

Yazarlar:

Münir TUNCER

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Biology 2000 Vol.24 Issue 4, pp.753-768

Belge Tipi:

Makale

Yayın Tarihi:

3/2000

Belge Dili:

Türkçe

Document ID (Org No.):

2000813934

Sıklık:

İki Aylık

eISSN:

1303-6092

pISSN:

1300-0152