Purification and Characterization of a Thermostable Raw Starch Digesting Amylase from aStreptomycessp. Isolated in a Milling Factory

Abstract

A raw starch utilizing microbe was isolated from mud in a milling factory. The 16S ribosomal DNA (rDNA) sequencing and morphological properties of the strain indicated that it belongs to the genus Streptomyces. A strongly raw starch digesting amylase was purified from the culture supernatant of the strain by chromatographic procedures. The specific activity of the enzyme was 11.7 U/mg, molecular mass 47 kDa, optimum pH 6.0, and optimum temperature 50 to 60 C. The enzyme showed sufficient activity even at 70 C. It was activated by calcium, cobaltous, and magnesium ions, and inhibited by copper, nickel, zinc, and ferrous ions. It formed maltose mainly from raw and gelatinized starch, and glycogen. No products were formed from glucose, maltose, maltotriose, pullulan, or cyclodextrins (CDs). The enzyme digested raw wheat, rice, and waxy rice starch rapidly, and raw corn, waxy corn, sweet potato, tapioca, and potato starch normally.

Purification and characterization of extracellular acidophilic -amylase from Bacillus cereus MTCC 10205 isolated from soil

“…These results are in accordance with those reported by Kaneko et al (2005), who observed an increase in amylase activity in the presence of Ca 2+ . The alpha amylase preparations used for starch liquefaction have been reported to show highest activity at pH 5.5-6.0 and require addition of calcium ion for stability (Vieille and Zeikus, 2001).…”

Isolation, identification and characterization of four cellulolytic actinomycetes and their cellulases

“…The higher liquefaction of cellulose due to enzyme activity at pH 6.5 to 7.5 was reported by many workers ( Malek et al1987, Araujo and Ward 1990, Hachiro and Kazuhiko 1991, Shailendra et al 1991, Hossain et al 1998, Hossain et al1999.The higher liquefaction of cellulose due to enzyme activity at 50˚C was reported by Kaneko et al 2005 andLee et al 2006. This observation also showed similarities with their reports.…”

Thermal Stability and Starch Degradation Profile of α-Amylase fromStreptomyces avermitilis

“…There are reports of maltose-producing amylases from Streptomyces, where certain quantities of G1 and other oligosaccharides were produced simultaneously. 8,9,19) SAV5981 might have a characteristic degradation property that differs from other maltose-producing amylases.…”

“…have weak thermal properties (thermostability and optimal temperature) compared to amylases from other hosts such as Bacillus and Aspergillus species, [5][6][7] and they usually show high activity at ambient temperature or below 40 C, except in a few cases. 8,9) Streptomyces avermitilis is known to produce many secondary metabolites, and its genome sequence has been determined.…”