Effects of heavy
metals on Antarctic bacterial cell growth kinetics and degradation of waste
canola oil
K.N.M. Zahri1,
A. Zulkharnain2, C. Gomez-Fuentes3, S. Sabri4
and S.A. Ahmad1,5*
1Department of
Biochemistry, Faculty of Biotechnology and Biomolecular Sciences, Universiti
Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
2Department of
Bioscience and Engineering, College of Systems Engineering and Science,
Shibaura Institute of Technology, 307 Fukasaku, Minuma-ku, Saitama, 337 8570,
Japan
3Department of
Chemical Engineering, Universidad de Magallanes, Avda. Bulnes, 01855, Punta
Arenas, Región de Magallanes y Antártica Chilena, Chile
4Department of
Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti
Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
5National Antarctic
Research Centre, B303 Level 3, Block B, IPS Building, Universiti Malaya,
50603 Kuala Lumpur, Malaysia
*Corresponding Author Email : aqlima@upm.edu.my
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Abstract
Aim:
The aim of the present study was to study the effect of heavy metals on
growth kinetics of Antarctic bacterial in degradation of waste canola oil.
Methodology: The BS14 Antarctic bacterial community was
introduced in the minimal salt media containing 1 ppm of heavy metals (Cd,
Cr, Al, Zn, Ni, As and Co) with 1% waste canola oil, and the effects of heavy
metals on biodegradation of waste canola oil was analysed by gravimetric
analysis. The turbidity of bacteria was obtained through UV-visible
spectroscopy at 600 nm of wavelength for every 24 hr within seven days of
incubation period, and the data were regressed with linear and non-linear
kinetic equations.
Results:
The results demonstrated that Co was the most active metal that led to 4.217%
increase in waste canola oil and the least active metal in biodegradation of
oil was zinc, as it degraded the waste canola oil only to 29.26%. Overall,
the bacterial growth was inhibited in increasing order of Al > Cd>
As> Zn> Ni> Cr> Co whereas the waste canola oil biodegradation
was inhibited in the order of Zn> Cr> Ni> Al> Cd> As> Co.
The best fitted-regression model was determined by comparing the kinetic parameters
estimated between linear and non-linear model equations, where the R2 value
for non-linear regression was highest at 0.8421, and low sy.x at 0.324 for Ni
with a maximum growth rate (0.01131 hr-1) of the Antarctic
bacterial in degrading waste canola oil, meantime best-fitted in the linear
regression model was Zn with high R2 and growth constant values
(0.9082 and 0.2075 hr-1, respectively) as well as low value of
statistical error, which was 0.2075.
Interpretation: The presence of heavy metals in
Antarctic bacterial community could suppress the ability of bacteria to
degrade waste canola oil, and this can slower the rate of bacterial growth in
the kinetics studies. Hence, this work would be helpful in actual
bioremediation operations by understanding and manipulating the process of
the kinetics parameters.
Key
words:
Antarctic, Canola oil, Degradation, Heavy metal, Kinetic growth
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