African Journal of Biotechnology Vol. 6 (10), pp. 1181-1184, 16 May 2007   

ISSN 1684–5315 © 2007 Academic Journals        

Full Length Research Paper

Heat activation and stability of amylases from Bacillus species

Ajayi, Adedayo Olajide^1* and Fagade, Obasola Ezekiel²

¹Department of Microbiology, Adekunle Ajasin University, P.M.B. 01, Akungba Akoko

Ondo State, Nigeria.

²Department of Botany and Microbiology, University of Ibadan, Ibadan, Oyo State, Nigeria.

*Corresponding authors E-mail: jidet02@yahoo.com.

Accepted 20 April, 2007

Leitch and Collier sporulating Bacillus medium was used to isolate some strains of Bacillus species from soil, wastewater and food sources in Ibadan, Oyo State, Nigeria, by heat activation method. Heat treatment at 80oC allowed the growth of sporulating Bacillus species, in the culture sample source without other bacteria forms. The amylolytic Bacillus species isolated during the study were identified as Bacillus macerans, Bacillus coagulans Bacillus licheniformis, Bacillus circulans, Bacillus megaterium, Bacillus polymyxa and Bacillus subtilis. Heat treatment at 70oC denatured the β-amylase component of the amylase source while α-amylase retained its potency at this temperature. Calcium cations (Ca2+) enhance the enzyme production than Na+ which was less effective. Physiological studies show that an optimum temperature of 40^oC was suitable for the enzyme activity while temperature above 60oC reduced its activity unless positive measures are taken to stabilize it with relevant cations like Ca2+.

Key words: Activation, Bacillus, effect, heat, treatment.