Isolation and characterization of partially furified bacteriocin of Bacillus cereus (CF1) soil isolate

Abstract

Bacteriocins are proteinaceous antimicrobial substances produce by bacteria against closely related bacterial species. However their broad spectrum inhibitory activity has been observed against other microorganisms such as fungi. The aim of this study was to isolate and determine physical, chemical and biological characteristics of bacteriocin from B. cereus of soil origin. A Gram-positive spore forming bacilli coded as CF1 was isolated by pour plating technique from the soil sample of the cereal farm land of Kura local government area, Kano State Nigeria and identified as Bacillus cereus based on cultural, microscopic and biochemical characteristics. Bacteriocin was isolated from this B. cereus and partially purified by solvent method (cold acetone) and had broad spectrum inhibitory activity with MIC of 64 AU/ ml. This bacteriocin was thermo stable up to 121°C for 15 minutes and its activity was maintained at wider pH value of 2-12. Although, the bacteriocin isolated by this B. cereus was not affected by some chemical such as Urea, EDTA and Tween 80, other chemical such as SDS and trypsin enzyme deactivated its activity. It is therefore recommended that further studies be carryout on this bacteriocin to purify the bacteriocin using Poly Acryl Amide Gel Electrophoresis PAGE and to elucidate its sequence, to determine its molecular conformation and antibacterial activity on multi drug resistant pathogens.

Key words: Bacteriocin, Bacillus cereus, Broad spectrum, Tween 80 and Sodium Dodecyl Sulphate.