Sunday, April 29, 2007

Sequential production of amylolytic and lipolytic enzymes by bacteria isolated from petroleum contaminated soil

Nayara Bezerra Carvalho1, Ranyere Lucena de Souza1, Heizir F. de Castro2, Gisella M. Zanin3, Álvaro Silva Lima1, and Cleide M. F. Soares1. (1) Instituto de Tecnologia e Pesquisa, Universidade Tiradentes, Av. Murilo Dantas, 300, Farolandia, Aracaju - SE, 49032-490, Brazil, (2) Engineering School of Lorena, University of São Paulo, P.O.Box 116, Lorena - SP, 12602-810, Brazil, (3) Chemical Engineering Department, State University of Maringa, Av. Colombo, 5790, BL E-46, Maringa - PR, 87020-900, Brazil

Amylases and lipases are highly demanded industrial enzymes in various sectors such as food, pharmaceuticals, textiles and detergents. Amylases are of ubiquitous occurrence and hold the maximum market share of enzyme sales. Lipases are the most versatile biocatalyst and bring about a range of bioconversion reactions such as hydrolysis, interesterification, esterification, alcoholysis, acidolysis and aminolysis. The objective of this work is to present alternatives for amylolitic and lipolytic production using a bacterium strain isolated from petroleum contaminated soil under submerged fermentation. This was a sequential process, in which amyloglucosidase was first produced followed by lipase production, using as inductor agents starch (2%) and olive oil, respectively. Experiments were carried out in 500 mL Erlenmeyer flasks with 200mL medium containing (%, w/v): KH2PO4 (0.1), MgSO4.7H2O (0.05), NaNO3 (0.3), yeast extract (0.6), peptone (0.13). Fermentation conditions were pH 5.0; 30 °C and stirred speed (200rpm). Maximum activities for amyloglucosidase and lipase were, respectively, 2.60U/mL and 1,028U/mL. These results have shown a promising methodology to obtain both enzymes and future work is underway in order to test the feasibility of using industrial waste resources for the production of these enzymes.