Study on Production of Extracellular Amylase from Bacillus subtilis Strain KPA under Mild Stress Condition of Certain Antimicrobials

Abstract

The present study was investigated to improve Bacillus subtilis strain KPA for extracellular amylase production under mild stress condition of certain antimicrobials. The novel isolated bacterial culture was exposed to different concentrations of Allium sativum, ampicillin and Mercuric chloride at their sub- MIC values for 24 to 72 h. Exposure of Allium sativum and ampicillin to strain KPA did not give improved extracellular amylase production. Allium sativum and ampicillin at the concentration of 250 μ l and 100 μ l were able to induce strain KPA for amylase production of 1896.257 U/ml/min and 1740.976 U/ml/min respectively after 48 h of incubation. On the other hand Mercuric chloride at the concentration of 250 μ l was able to improve strain KPA even after 24 h of incubation for maximum enzyme production (2024.136 U/ml/min) compared to the enzyme produced (1854.099 U/ml/min) by the parental strain. The extracellular enzyme produced by strain KPA under mild stress condition of certain antimicrobials tested here were 2-3 fold higher than that of previously isolated Bacillus strains. The results clearly conclude the role of novel isolated strain in various industries such as textile, paper, pulp, food etc. due to enhanced production of amylase under mild stress conditions.