Abstract—Pecate lyase has great commercial significance in the feed and drink industries, pectate lyase is an enzyme catalyzing the hydrolysis of pectin, a plant polysaccharide that contributes to the structure of plant tissues, into galacturonic acid. Although several substrates for the production of pectate lyase have been reported as being economically effective such as utilization of pectin-rich substrate rather than pure pectin, however, there is still need to develop the substrate to make the entire process much cheaper and more effective. The present work deals with physiological studies on bacterial pectate lyase. Out of 50 spoilt cucumber and tomato samples from local markets in Baghdad city. Eighteen isolates from Erwiniachrysanthemi were obtained (36%). Pectate lyase activity was found in all isolates in primary and secondary screening and the isolate Erwinia chrysanthemiEc9 yielded the highest pectate lyase production. The enzyme activity was increased to 75.31U/ml when this isolate was cultivated under the optimal conditions which consisted of using basal medium containing (1.5%) (w/v) lemon peel extract and 0.02% (w/v) yeast extract with pH 6.0 at 25°C for 24 hour. The enzyme revealed maximum activity (88.34U/ml) with lemon peel powder (0.9% w/v), followed by orange peel and apple pomace powders with relative activities of 117,105 and 102%, respectively, as substrates. The best cofactors for this enzyme were Ca2+and Fe2+ with relative activities of 138 and 112%, respectively, and severely inhibited in presence of Hg2+and Cu2. Consequently, lemon peel has a potential as an effective and much cheaper (economical) substrate for pectate lyase production and pectate lyase activity in comparison with traditionally used substrates like polygalacturonic acid and other saccharides.

Index Terms—pecata lyase, erwinia chrysanthemi

Cite: Sahira N. Muslim, Israa M.S. AL_Kadmy, Alaa N. Mahammed, Hadeel K. Musafer, and Sraa N. Muslim, "Detection of the Optimal Conditions for Pectate lyase Productivity and Activity by Erwiniachrysanthemi," Journal of Medical and Bioengineering, Vol. 4, No. 3, pp. 184-191, June 2015. Doi: 10.12720/jomb.4.3.184-191