title: Purification and partial characterization of an acidic α-amylase from a newly isolated Bacillus subtilis ZJ-1 that may be applied to feed enzyme.
abstract: An amylase-producing strain was isolated from soy sauce and designated as Bacillus subtilis ZJ-1. Purification of α-amylase from B. subtilis ZJ-1 to homogeneity by ethanol fractionation, ultrafiltration, and Sephadex G-100 gel filtration resulted in recovery of 8.9% and a specific activity of 542.7 U/mg protein. The molecular mass was estimated to be 58 kD by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme reached its maximum activity at a pH of 5.0 and a temperature of 50°C. The enzyme remained at 89.4 ± 3.0% of its activity at 40°C. The enzyme retained 87.7 ± 3.7% and 63.4 ± 2.9% of its original activity at 40°C after a 60-min incubation in the presence of 5 mM CaCl2 at a pH of 5.0 and 4.0, respectively. These properties indicate that the novel enzyme has a theoretically high survival rate and excellent starch catalytic efficiency in the typical chicken gastrointestinal-tract environment (pH 3.5-7.0, 40°C). In addition, the enzyme remained at 78.4 ± 3.6% of its activity after a 5-min incubation at 80°C, which demonstrates that the enzyme could maintain a high survival rate in the pelleting process of feed production. The characteristics just described make this enzyme a good candidate for use as a chicken feed enzyme.
authors.affiliation: a Feed Biotechnology Laboratory, College of Animal Science , South China Agricultural University , Guangzhou , P. R. China.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Liu
authors.forename: Weiguang
authors.initials: W
authors.lastname: Xia
authors.forename: A Y
authors.initials: AY
authors.lastname: Abdullahi
authors.forename: Fan
authors.initials: F
authors.lastname: Wu
authors.forename: Qin
authors.initials: Q
authors.lastname: Ai
authors.forename: Dingyuan
authors.initials: D
authors.lastname: Feng
authors.forename: Jianjun
authors.initials: J
authors.lastname: Zuo
mesh_terms: D000143:Acids / Q000737:chemistry; D001412:Bacillus subtilis / Q000201:enzymology*; D001483:Base Sequence; D017931:DNA Primers; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D016133:Polymerase Chain Reaction; D013696:Temperature; D000516:alpha-Amylases / Q000737:chemistry*
chemical_list: D000143:Acids; D017931:DNA Primers; D000516:alpha-Amylases
keywords: Bacillus subtilis ZJ-1; acidic α-amylase; feed enzyme; pH stability; thermostability