Pseudomonas aeruginosa NR.22 – local hydrocarbon degrader species originated from crude oil non-exploration site: isolation, survivability and hydrocarbon degradation study

• Published in: Desalination and Water Treatment
• Main Author: Syuhadah B.H.; Raikhan N.H.N.
• Format: Article
• Language: English
• Published: Desalination Publications 2022
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85134578874&doi=10.5004%2fdwt.2022.28473&partnerID=40&md5=ea1fc2cde9ea2902db455a6f5b62ed47

Pseudomonas aeruginosa as a hydrocarbon degrader is not a something new. In fact, there were numerous published papers reported the excellent performance of this species as a hydrocarbon degrader. However, most of the previous study used P. aeruginosa that was isolated directly from the contaminated site. This however resulting a gap of information in understanding the relationship between species growth environmental condition on their hydrocarbon degrading ability. Therefore, in this study, enrichment method was used to isolate P. aeruginosa NR.22 (Ps.NR.22) from crude oil non-impacted recreational lakes in Section 7, Shah Alam, Selangor, Malaysia. The survivability and impact of crude oil concentrations (2% (w/v), 5% (w/v) and 7% (w/v)) on the kinetic growth of free moving Ps.NR.22 throughout the fermentation period were monitored through the changes of cell density till constant dropped of cell density obtained. 5% (w/v) was the ideal concentration to support the growth of Ps.NR.22 as specific growth rate, percentage of overall crude oil degraded by Ps.NR.22 and decay coefficient of cells in this culture medium recorded the highest (0.4787 d–1, 94.1%, 0.0097 h–1) followed by 7% (w/v) (0.3863 d–1, 67.17%, 0.0016 h–1) and 2% (w/v) (0.3325 d–1, 50.02%, 0.003 h–1). High decay coefficient value of cells in 5% (w/v) might be linked with active and fully utilization of crude oil during exponential phase. Next, potential of free moving Ps.NR.22 as a biodegradation tool was further expanded by evaluating its compatibility with membrane separation technology for removal of hydrocarbons. This was done by introducing 5% w/v crude oil water mixture to the immobilized Ps.NR.22 in a filtration cell through dead end filtration method. Accumulation of crude oil molecule on/within the surface of porous support ceramic activated the Ps.NR.22 hydrocarbon degrading mechanism. As a result, it was found out that, support ceramic with presence of Ps.NR.22 demonstrating de-fouling potential at minute 125 while with absence of Ps.NR.22 the flux rate kept on declining till the filtration ended. This showed that by Ps.NR.22 have the potential to enhance the performance of support ceramic in removing hydrocarbon. © 2022 Desalination Publications. All rights reserved.