Malays. Appl. Biol. (2018) 47(3): 59–69
BIOCHEMICAL AND IN-SILICO STRUCTURAL ASSESSMENTS
OF AN Acinetobacter haemolyticus LIPASE KV1 ISOLATED FROM
AN OIL PALM MILL EFFLUENT
KALAIVANI BATUMALAIE1, NAJI ARAFAT MAHAT1, FAHRUL HUYOP2 and
ROSWANIRA ABDUL WAHAB1*
1Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia,
81310 UTM Johor Bahru, Malaysia
2Department of Biotechnology and Medical Engineering,
Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia,
81310 UTM Johor, Malaysia
*E-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it
Accepted 25 May 2018, Published online 30 June 2018
ABSTRACT
The use of microbial enzymes as biocatalysts for a myriad of commercial processes are currently trending owing to their versatility and, their use is considerably greener than the chemically-assisted methods. In this regard, this study reports the comprehensive biochemical characterization of a lipase from novel Acinetobacter haemolyticus KV1 bacteria. The intracellular lipase was purified to ~3.5-fold using consecutive treatments of ammonium sulfate precipitation, dialysis and DEAE-cellulose ion exchange chromatography. The purified lipase exhibited maximum relative activity at 40°C and pH 8.0, respectively. Lipase KV1 was significantly activated (p < 0.05) in reactions supplemented with metal ions, Na+, Ca2+, K+ and Mg2+ (112–128%) as well as surfactants, Tween 20–80 (110–143%). The lipase hydrolyzed a wide range of oils with tributyrin (140%) being the preferred ones. Reducing (PMSF, DTT, ?-mercaptoethanol) and chelating (EDTA) agents significantly inhibited the lipase (p < 0.05) and, significant inhibition was also evident for Triton-X100, SDS, SLS and CTAB (p < 0.05). Interestingly, lipase KV1 retained its relative activities at > 50% for up to 24 h for pH between pH 7-11. Therefore, the full characterization of lipase KV1 reported in this study deserves scientific and economic considerations.
Key words: Acinetobacter haemolyticus, lipase, purification, biochemical characterization, reducing agents
