Optimization of Culture Conditions for Lipase Production by Pseudomonas aeruginosa ECS3

Abstract

Lipases are hydrolytic enzymes with different biotechnological applications in food, detergents, pharmaceuticals, paper, and pulp industries. In lipase-producing bacteria, the encoding genes are responsible for enzyme synthesis. Optimization of medium parameters is an essential factor in the large-scale production of enzymes of biotechnological importance, and this served as the basis for this study. In this study, isolates ECS1, ECS3, ECS11, ECS14, ECS 19, ECS24, and ECS28 were screened for lipase production on tributyrin agar plates. The highest lipase-producing isolate was identified by sequencing the 16S rRNA region following a PCR procedure using a specific primer. The presence of the LipA gene in the isolate was confirmed by polymerase chain reaction (PCR) amplification of their specific primers. In addition, some physical and nutritional parameters were optimized for lipase production. On tributyrin agar plates, isolate ECS3 had the highest zone of hydrolysis (12mm) and was therefore selected. Based on the 16S rRNA sequencing, the highest lipase producer was identified as Pseudomonas aeruginosa ECS3. This study also ascertained the presence of the LipA gene in this bacterium with a positive band of 371 bp. Optimum activities were observed at pH (8), temperature (35oC), and incubation period (24 h). The activity of Pseudomonas aeruginosa ECS3 lipase was enhanced by yeast extract (0.5% w/v), lactose (0.5% w/v), agitation speed (120 rpm), and 1% substrate concentration. The study showed the influence of different culture conditions on lipase production by Pseudomonas aeruginosa ECS3 with the LipA encoding gene.