Investigating the Ability of Diverse Native Bacillus Species to Produce Hydrolytic Enzymes Using Agar Plate Assay

Abstract

Hydrolytic enzymes of Bacillus attracting a great attention due to their various applications in industrial bioprocesses. In this work, out of 525 Bacillus isolates, 40 were screened for their potential capacity to produce hydrolytic enzymes including xylanase, lipase, amylase, pectinase, protease and carboxymethyl cellulose (CMC) using agar plate assay. A pure culture of each isolate was streaked on the surface of agar media containing suitable substrate specific for every enzyme activity, and the diameter of hydrolytic zones were measured. Data showed clear zones around the colonies which were interpreted as evidence of the enzymes activities. The isolates were able to generate at least one of these enzymes among which CMC and protease were the most common enzymes detected in 40 isolates; amylase in 39, xylanase in 36, lipase in 32 and pectinase in 26. Based on 16S rRNA gene sequencing the isolates were classified as B. atrophaeus, B. amyloliquefaciens, B. subtilis, Paenibacillus polymyxa, B. simplex and B. tequilensis. The native B. tequilensis isolates formed the largest zone clearance and had high abilities to produce five hydrolases. The isolates which had the largest enzymatic activity zones and the largest diameter of the clear hydrolysis zones on agar plates were submitted for further research work and enzyme-based industrials.

Keywords

• xylanase
• lipase
• amylase
• pectinase
• protease
• carboxymethyl cellulose
• bacillus species
• agar assay