A comparative study of pectinolytic enzyme production by Bacillus species

Abstract

The economic and ecological function of pectinase enzymes in industries is gaining much attention with the need of highly productive strains of microorganisms to reduce production cost. The present investigation is a comparative evaluation of Bacillus sp. pectinases. The three isolates isolated from agro-waste, Bacillus stearothermophilus, Bacillus cereus and Bacillus subtilis, showed very high pectinase activities with pectin as the substrate. The three isolates also showed varying degree of preference for banana peels and wheat bran but their activity towards orange peel was very low compared to other substrate. The effect of temperature on the pectinase of the three isolates showed that B. stearothermophilus had optimum temperature at 60°C while B. cereus and B. subtilis both showed optimum activity at 50°C. On the effect of pH, B. stearothermophilus, B. cereus and B. subtilis showed optimum pectinase activities at pH 7.5, 8.0 and 9.0, respectively. Metal ions enhanced the activity of pectinase produced by the three isolates. The study exhibited that B. stearothermophilus gave the most pectinase activity, optimum temperature and a moderate alkaline pH, possibly making it a better source for industrial purpose.   Key words: Pectinase, enzymes, pectin, bacteria, Bacillus species.