Production and Properties of α-glucosidase from Hansenula anamola

Abstract

Abstract: A large number of yeast isolates isolated from Egyptian soils were screened qualitatively and quentitavilly for their α-glucosidase activity. Isolate No. 96 was the most active isolate. This isolate was characterized and identified as Hansenula anamola. Results showed that its enzyme was intracellulary produced. Therefore permealization treatments were carried out using chemical and physical treatments. Data clear show that Toluene was the most suitable for releasing active enzyme with a good yield from yeast cell. On the other hand, the enzyme was found to be constitutively synthesized and is highest enzyme production was obtained when sucrose was used in medium with 1% final concentration, followed by maltose. Furthermore, different organic and inorganic nitrogen sources were added separately to the growth medium instead of its nitrogen source was used.The highest enzyme production was obtained in 43 4 the presence of urea followed by (NH ) PO . Partial purification of the enzyme using different saturations of ammonium sulphate followed by gel filtration on Sephadex G-100 was carried out. Studies on the purified enzyme showed that 43 C was the most suitable temperature for activity and the enzyme was o only stable when stored at 35 C for 60 min. At higher temperatures the enzyme was not stable which o clear indicate that the enzyme are not heat stable. In addition pH 7.0 was the most suitable pH for enzyme activity and stability. On the other hand α-glucosidase activity was increased and enhanced in the presence of potassium, ammonium, or magnesium ions in the assay mixture, while lithium or barium shows some inhibitory effects. In addition, enzyme showed high affinity toward ρ-Nitrophenyl-α-Dglucopyranoside followed by Sucrose