Novel extracellular hyper acidophil and thermostable α‐amylase from Micrococcus sp.NS 211

Abstract

Among several bacteria examined in this study, a hyper acidophil and thermostable Micrococcus sp.NS 211 designated as M.Amy NS 211 was selected for production of amylase using starch agar plates with following incubation at 85°C. Identification by 16SrRNA on selected bacterium disclosed the highest similarity for protean regions of this gene, 27 F and 1492R as Micrococcus sp.NS 211. Although activity of M.Amy NS 211 was established at temperatures between 70 and 110°C and pH ranges 1.2–8.0, the optimum temperature and pH was achieved at 85°C and 3.5 in sodium citrate buffer system respectively. Two‐step chromatography was performed using (CM Bio‐Gel A) and (Bio‐Gel A‐150) columns to purify 84 kDa hyper acidophil and thermostable α‐amylase. SDS‐PAGE analysis showed molecular mass and amylolytic activity as single band. Enhancement of enzyme activity was obtained in presence of 5 mM MnCl2 (298%), CaCl2 (347%), FeCl2 (211%), MgCl2 (253%), ZnCl2 (146%), NiCl (142%), NaCl (141%), Na‐sulfate (153%) while inhibition was observed with (5 mM) EDTA, PMSF (3 mM), urea (8 M), and SDS (1%) at 143, 134, 43, and 119%, respectively. M.Amy NS 211 can be applied in laundry detergents, textile, and modern relevant industrial processes at extreme temperatures and under acidic conditions.

Characterization of an acidophilic and thermostable α‐amylase from Alicyclobacillus sendaiensis NUST

“…(66 kDa) 5, Bacillus acidocaldarius (68 kDa) 7 and Micrococcus sp. (84 kDa) 1, ASA was smaller. The α‐amylases isolated from Bacillus sp.…”

“…Residual enzyme activity was reduced by 88%, when 1% urea was used. Enzyme denaturation by urea suggests that the enzyme is mostly composed of hydrophobic amino acids 1. EDTA demonstrated a non‐significant inhibition of the enzyme activity and a slight inhibition was evidence of the purified enzyme being a metallo‐enzyme 3.…”

“…The history began in 1811 when the first starch degrading enzyme was discovered by Kirchhoff. Amylases have great applications for biotechnology, constituting a class of industrial enzymes having 25% of the world enzyme market 1. α‐Amylases (1,4‐α‐ D ‐glucan‐glucanhydrolase, EC.…”

“…Bacillus acidocaldarius 7, Bacillus caldovelox 8, Alicyclobacillus acidocaldarius 9, 10, Micrococcus sp. 1, and Aspergillus niger 11, are good producers of acidophilic and thermostable amylases.…”