Effect of inoculum size, inducer and metal ion on lipase production by Rhodococcus strain UCC 0009

¹ Institute of Bio-IT Selangor, Universiti Selangor, Jalan Zirkon A7/A, Seksyen 7, 40000 Shah Alam, Selangor Darul Ehsan, Malaysia.
² Centre for Foundation and General Studies, Universiti Selangor, Jalan Timur Tambahan, 45600 Bestari Jaya, Selangor Darul Ehsan, Malaysia.
³ Faculty of Engineering and Life Sciences, Universiti Selangor, Jalan Timur Tambahan, 45600 Bestari Jaya, Selangor Darul Ehsan, Malaysia.

^* Corresponding author: maegala@unisel.edu.my; maegala_81@yahoo.com

Abstract

Lipases are critical enzymes for industrial applications such as in the food and pharmaceutical fields. Therefore, the discovery of new lipases with enhanced characteristics are always encouraged. Thus, the present study explored the ability of a novel bacterial strain isolated from a tropical climate for lipase production. The optimization method using the one-variable-at-a-time approach was adopted to obtain increased production of lipase. The strain identified as Rhodococcus strain UCC 0009 was able to generate specific lipase activity of 11.67^a ± 0.00 mU/mg at optimized conditions of 8 % (v/v) inoculum concentration, 1 % (v/v) olive oil as the inducer, and the addition of Ca²⁺ions. The specific lipase activity increased by 162 % when the optimization using a one-variable-ata-time approach was adopted compared to that of the non-optimized counterpart, signifying this experimental phase’s importance. The present study’s findings revealed the potential of utilizing Rhodococcus strain UCC 0009 as a green lipase producer for application in bioremediation and biotransformation at an industrial scale. Further study concentrating on enzyme characterization and improving culture conditions for conducive production of lipase via statistical optimization using response surface methodology (RSM) will be attempted to elucidate further the superiority of lipase obtained from local resources.