Study on Some Properties of Calcium-dependent a -Amylase from Bacillus subtilis through Submerged Fermentation of Wheat Bran

Abstract

University of the Punjab new campus Lahore PakistanThis study reveals the production of α-amylase through Bacillus subtilis by submerged fermentation of wheat bran as a substrate. Various conditions were optimized and maximum production was observed at initial medium pH of 7.0, incubation temperature of 35 °C with agitation speed of 140 rpm for 48 h of fermentation period. Peptone, ammonium sulphate and soluble starch favored enzyme production as nitrogen and carbon source, respectively. The crude α-amylase was purified 2.03-fold by column (sephadex G-100) chromatography having specific activity of 480.0 U mg -1 . The purified enzyme had molecular mass of 54.18 kDa as determined by 12 % SDS-PAGE. The optimum pH and temperature of the enzyme was 8.5 and 60 °C, respectively. Ca 2+ played an important role in the stability of the enzyme retaining relative activity of 87 % and 67 % at pH 9.5 and 80 °C, revealing the Ca 2+ dependency respectively. The enzyme was highly stable towards surfactants and oxidizing agents. Kinetic study indicated that the enzyme exhibit K m and V max value of 4.4 mg mL -1 and 714.2 U mL -1 using soluble starch as a substrate respectively.

The optimized production, purification, characterization, and application in the bread making industry of three acid‐stable alpha‐amylases isoforms from a new isolated Bacillus subtilis strain US586

“…Commonly, bacterial α‐amylases are known to be stable in the presence of calcium ion. Indeed, Irfan () indicated that calcium played a key role for amylases stability and activity. Few studies reported that amylases were Ca 2+ ‐independent (Sajedi et al, ).…”

“…Indeed, Irfan (2017) indicated that calcium played a key role for amylases stability and activity. Few studies reported that amylases were Ca 2+ -independent (Sajedi et al, 2005).…”

Enhanced Bacterial α-Amylase Production Using Mutant Strains Through Submerged Fermentation

“…Bacillus subtilis BI19 and Bacillus licheniformis B4-423 had the highest crude-amylase enzyme activity at pH 6.0 and pH 5.0, respectively (Dash et al, 2015;Wu et al, 2018). The optimum pH of α-amylase was reported 8.5 which was produced from B. subtilis by using wheat bran as substrate in submerged fermentation (Irfan et al, 2016). The optimal activity of α-amylase produced by B. subtilis was also observed at pH 6.0 (Özdemir et al, 2011).…”

Utilization of fruit wastes for enzyme production in submerged fermentation

“…Amylase assay. Activity of α-amylase was calculated using amylase assay conditions [8]. Reaction mixture having 0.5 mL of crude enzyme and 0.5mL of 1% starch solution (pH 7) incubated at 60°C for 30 min.…”