Isolation and Characterization of Protease Producing Bacteria from Soil, in Arba Minch University, Abaya Campus

Abstract

Microbes are ubiquitous and live in familiar settings such as soil, water, food and animal intestines as well as in more extreme setting such as rocks, glaciers, hot springs and deep-sea vents. They are essential component of the biodiversity as they account for 50% of the living biomass of this planet. The aim of this work was isolation and screening of protease producing bacteria from soil collected from the study area. Isolation of protease producing bacteria was performed by the serial dilution and spread plate technique using skim milk agar medium. Accordingly, 131 isolates were positive on skim milk agar and of which 13 (10%) of them are protease producer. Four best isolates were selected on the basis of their clear zone size, one from each site for further study. IS-4 has larger clear zone size with 10.5mm followed by IS-2 (6mm). All potential isolates have circular in shape of colony and flat in height of colony except IS-1 which is irregular and raised respectively. Most of potential isolates have opaque in their colonial optical density. All isolates were found to be Gram positive and spore producers. Morphological and biochemical results have revealed that three of four active enzyme producing bacteria are identified as Bacillus spp. Members of the genus Bacillus produce a large variety of extracellular enzymes (proteases) particularly significant for industrial application.