The Use of Response Surface Methodology as a Statistical Tool for the Optimisation of Waste and Pure Canola Oil Biodegradation by Antarctic Soil Bacteria

Abstract

Hydrocarbons can cause pollution to Antarctic terrestrial and aquatic ecosystems, both through accidental release and the discharge of waste cooking oil in grey water. Such pollutants can persist for long periods in cold environments. The native microbial community may play a role in their biodegradation. In this study, using mixed native Antarctic bacterial communities, several environmental factors influencing biodegradation of waste canola oil (WCO) and pure canola oil (PCO) were optimised using established one-factor-at-a-time (OFAT) and response surface methodology (RSM) approaches. The factors include salinity, pH, type of nitrogen and concentration, temperature, yeast extract and initial substrate concentration in OFAT and only the significant factors proceeded for the statistical optimisation through RSM. High concentration of substrate targeted for degradation activity through RSM compared to OFAT method. As for the result, all factors were significant in PBD, while only 4 factors were significant in biodegradation of PCO (pH, nitrogen concentration, yeast extract and initial substrate concentration). Using OFAT, the most effective microbial community examined was able to degrade 94.42% and 86.83% (from an initial concentration of 0.5% (v/v)) of WCO and PCO, respectively, within 7 days. Using RSM, 94.99% and 79.77% degradation of WCO and PCO was achieved in 6 days. The significant interaction for the RSM in biodegradation activity between temperature and WCO concentration in WCO media were exhibited. Meanwhile, in biodegradation of PCO the significant factors were between (1) pH and PCO concentration, (2) nitrogen concentration and yeast extract, (3) nitrogen concentration and PCO concentration. The models for the RSM were validated for both WCO and PCO media and it showed no significant difference between experimental and predicted values. The efficiency of canola oil biodegradation achieved in this study provides support for the development of practical strategies for efficient bioremediation in the Antarctic environment.

Optimisation of Various Physicochemical Variables Affecting Molybdenum Bioremediation Using Antarctic Bacterium, Arthrobacter sp. Strain AQ5-05

“…The reduction activity plummets as the temperature increases and the Mo-blue production halts as the temperature reaches 20 • C, while bacterial growth declines steadily with the increase in temperature. Previous reports stated that most Antarctic bacteria are psychrotolerant rather than strictly psychrophilic [8,16,33,34]. Therefore, most native microorganisms can withstand high temperature fluctuations considering the weather and climate of the continent.…”

Evaluation of Heavy Metal Tolerance Level of the Antarctic Bacterial Community in Biodegradation of Waste Canola Oil

“…The waste canola oil (WCO) was acquired directly from the station. The sampling method is described in more detail in Zahri et al [25].…”

“…The incubation conditions were at 13 • C and the sample was shaken in a 150 rpm orbital shaker for 6 days. These conditions were obtained based on the past study on the optimization of biodegradation of WCO using same bacterial community sample (BS14) [25].…”

Mathematical Modelling of Canola Oil Biodegradation and Optimisation of Biosurfactant Production by an Antarctic Bacterial Consortium Using Response Surface Methodology

“…The potential of microorganisms has been recognized in the development of strategies to remediate oil spills. Specifically relating to the biodegradation of waste cooking oils, Zahri et al [9] studied the degradation of waste canola oil (WCO) and pure canola oil (PCO) using a consortium of native Antarctic soil bacteria. Microorganisms are increasingly used to treat and transform waste products, and are considered as an eco-friendly technology for the remediation of contaminated environments.…”

“…A native Antarctic soil bacterial consortium, designated BS14, has been previously confirmed to degrade canola oil [9,14]. Further studies on the potential of this consortium are described here, involving degradation kinetics modelling using secondary non-linear regression.…”